cssi/SciSciGPT-SciSciNet huggingface dataset:
Friction and Fracture of Single-Crystal Silicon Carbide in Contact with Itself and Titanium

An investigation was conducted to examine the friction properties and mechanical behavior of single-crystal silicon carbide (0001) surface sliding against itself and against polycrystalline titanium. The results indicate hexagon-shaped pits of silicon carbide and the formation of platelet hexagon-shaped wear debris of silicon carbide due to cleavages of both prismatic and basal planes as a result of silicon carbide sliding against itself. The fracturing of silicon carbide also occurs near the adhesive bond to titanium. The wear debris produced by brittle fracture plows the titanium and transfers to it. Further, the silicon carbide wear debris, which adhered and transferred to titanium, plows the silicon carbide surface and transfers back to it
The Effect of Carbohydrates and Arginine on Arginine Metabolism by Excised Bean Leaves in the Dark

The effect of carbohydrate on arginine utilization by excised bean ( Phaseolus vulgaris L. var. Tendergreen) leaves in the dark was studied by adding arginine to leaves differing in carbohydrate levels, and measuring the arginine content of the leaves at intervals. In nonstarved leaves, the arginine content decreased steadily after vacuum infiltration of 10 mm arginine and was essentially completely utilized by 36 hours after infiltration. In starved leaves, the arginine content did not decrease except for a brief period of about 4 hours after infiltration. The distribution of 14 C after adding 14 C-arginine to starved and nonstarved leaves indicated that the presence of carbohydrates in the leaves stimulates the utilization of arginine for protein synthesis and conversion to other amino acids, organic acids, and CO 2 (catabolism). Adding sucrose along with arginine to starved leaves stimulated this utilization of arginine for both protein synthesis and catabolism. This effect of sugar on catabolism is different than results of similar studies done previously with proline. Increasing the concentration of added arginine greatly increased arginine catabolism but had a relatively small effect on utilization of arginine for protein synthesis. This result is the same as similar results from adding different concentrations of proline to excised leaves.
Evaluation of forest cover estimates for Haiti using supervised classification of Landsat data

Abstract This study uses 2010–2011 Landsat Thematic Mapper (TM) imagery to estimate total forested area in Haiti. The thematic map was generated using radiometric normalization of digital numbers by a modified normalization method utilizing pseudo-invariant polygons (PIPs), followed by supervised classification of the mosaicked image using the Food and Agriculture Organization (FAO) of the United Nations Land Cover Classification System. Classification results were compared to other sources of land-cover data produced for similar years, with an emphasis on the statistics presented by the FAO. Three global land cover datasets (GLC2000, Globcover, 2009 , and MODIS MCD12Q1), and a national-scale dataset (a land cover analysis by Haitian National Centre for Geospatial Information (CNIGS)) were reclassified and compared. According to our classification, approximately 32.3% of Haiti's total land area was tree covered in 2010–2011. This result was confirmed using an error-adjusted area estimator, which predicted a tree covered area of 32.4%. Standardization to the FAO's forest cover class definition reduces the amount of tree cover of our supervised classification to 29.4%. This result was greater than the reported FAO value of 4% and the value for the recoded GLC2000 dataset of 7.0%, but is comparable to values for three other recoded datasets: MCD12Q1 (21.1%), Globcover (2009) (26.9%), and CNIGS (19.5%). We propose that at coarse resolutions, the segmented and patchy nature of Haiti's forests resulted in a systematic underestimation of the extent of forest cover. It appears the best explanation for the significant difference between our results, FAO statistics, and compared datasets is the accuracy of the data sources and the resolution of the imagery used for land cover analyses. Analysis of recoded global datasets and results from this study suggest a strong linear relationship (R2 = 0.996 for tree cover) between spatial resolution and land cover estimates.
Inhibitory effects of combinations of three phenolic acids on grain sorghum germination

Abstract Ferulic acid (FA), p -coumaric acid (pCA) and vanillic acid (VA) were tested to establish threshold levels required for inhibition of sorghum seed germination. An equimolar combination of 3.3 × 10 −3 M of each of the 3 phenolics showed synergistic inhibition of germination. This combination of the three also depressed germination more than any combination of two of these phytotoxins. Shoot elongation in germinating sorghum was depressed by 3.3 × 10 −3 M of either FA or pCA, but not VA. At the concentrations used in combination experiments, VA seemed to antagonize some of the inhibition of FA and pCA on shoot elongation.
GFP: from jellyfish to the Nobel prize and beyond

On December 10, 2008 Osamu Shimomura, Martin Chalfie and Roger Tsien were awarded the Nobel Prize in Chemistry for “the discovery and development of the green fluorescent protein, GFP”. The path taken by this jellyfish protein to become one of the most useful tools in modern science and medicine is described. Osamu Shimomura painstakingly isolated GFP from hundreds of thousands of jellyfish, characterized the chromophore and elucidated the mechanism of Aequorean bioluminescence. Martin Chalfie expressed the protein in E. coli and C. elegans, and Roger Tsien developed a palette of fluorescent proteins that could be used in a myriad of applications.
PSEUDOPOTENTIAL CALCULATION OF THE STACKING FAULT ENERGY IN DIAMOND, GERMANIUM, AND GREY TIN

Abstract The intrinsic stacking fault energies of diamond, germanium and grey tin have been calculated by the pseudopotential method to a second order perturbation approximation. The calculated value for germanium, 26 erg/cm2, falls within 50% of the experimental value determined by the weak-beam technique in electron microscopy. The value for diamond, questionable because of possible poor convergence of the method, is very large, 1860 erg/cm2. Grey tin exhibits a small value, 3 erg/cm2, which could in principle be easily measured experimentally.
Growth modes in metal-organic molecular beam epitaxy of TiO2 on r-plane sapphire

Phase pure, epitaxial (101) rutile TiO2 films were grown on (012) sapphire substrates at temperatures between 485 and 725 °C using metal-organic molecular beam epitaxy with titanium tetraisopropoxide as the Ti source. Growth modes and rates were investigated as a function of substrate temperature using reflection high-energy electron diffraction, x-ray reflectivity, atomic force microscopy, and transmission electron microscopy. Growth rates were as high as 125 nm/h. The influence of additional oxygen supplied from a rf plasma source was investigated. Without oxygen plasma, the growth rate exhibited reaction and flux-limited regimes and layer-by-layer growth was observed in the initial stages of film growth. With oxygen plasma the growth rate became independent of temperature; films grew initially in step-flow mode and were insulating. The mechanisms for the different growth modes as a function of film thickness, temperature, and presence of oxygen are discussed.
Safety of Electroconvulsive Therapy in Patients With Unrepaired Abdominal Aortic Aneurysm: Report of 8 Patients

Objectives Patients with unrepaired abdominal aortic aneurysm (AAA) may have depression and other psychiatric disorders for which electroconvulsive therapy (ECT) may be recommended. It is unclear whether ECT, which transiently, yet markedly, increases blood pressure and heart rate, can be safely performed in patients with AAA. We investigated the safety of ECT in patients with unrepaired AAA. Methods A retrospective review was conducted of the medical records of all patients with unrepaired AAA who underwent ECT for severe depressive syndromes at Mayo Clinic, Rochester, Minn, between January 1, 1995, and June 30, 2007. Results Eight patients (5 men and 3 women) with unrepaired AAA who underwent ECT were identified. Median age was 78.5 years (range, 67-83 years). All patients had AAA (median diameter, 3.95 cm [range, 3.0-5.2 cm]). The median number of treatments was 8.5 (range, 4-48). None of the patients died during the periprocedural period or experienced symptoms or signs suggestive of AAA expansion or rupture. Follow-up imaging data were available for 6 patients whose median post-ECT AAA diameter was 4.65 cm (range, 3.3-5.3 cm). Expansion of AAA ranged from 0.1 cm (for 11 and 13 months in 2 patients) to 1.0 cm (for 29 months in 1 patient), which is less than the expected mean expansion rates for AAAs of these diameters. Conclusions Electroconvulsive therapy was safe for 8 patients with unrepaired AAA treated at our institution. Our findings may be informative to clinicians who manage the care of patients with unrepaired AAA who are undergoing ECT.
A study of thermal stability of polyester containing phenyl phosphonate unit for flame retardant fiber

Abstract Phenyl phosphonic acid (PPA) was chosen as a comonomer to manufacture flame retardant polyester fiber. The yield based on PPA is less than 55% by a conventional polyester formation process. Different factors which might affect the yield of the copolymerization were investigated. The phosphorus residues in the reactor during the process of polymerization were monitored. It is found that the phosphorus residues decrease sharply in the high vacuum stage. This indicates that factors which increase the molecular weight of the prepolymer containing phenyl phosphonate unit will promote the yield of the copolymerization. In order to get an insight into the low yield of the copolymerization, the compounds containing phenyl phosphonate unit, bis(2-naphtholyloxyethyl) phosphonate (BNEP) and bis( p -methoxycarbonyl phenyl) phosphonate (BMPP) were synthesized for model studies. The preliminary results showed that these compounds decompose significantly above 240 °C. This suggests that the low yield of the PPA polymerization process may be attributed to the thermal instability of the OP bond in the phenyl phosphonate unit at the polymerization temperature.
Lithium diisopropylamide-mediated ortholithiations: lithium chloride catalysis.

Ortholithiations of a range of arenes mediated by lithium diisopropylamide (LDA) in THF at −78 °C reveal substantial accelerations by as little as 0.5 mol % of LiCl (relative to LDA). Substrate dependencies suggest a specific range of reactivity within which the LiCl catalysis is optimal. Standard protocols with unpurified commercial samples of n-butyllithium to prepare LDA or commercially available LDA show marked batch-dependent rates—up to 100-fold—that could prove significant to the unwary practitioner. Other lithium salts elicit more modest accelerations. The mechanism is not discussed.
Women men and contraceptive sterilization.

Abstract Objective: To review the social and behavior contexts of decisions about contraceptive sterilization and to analyze factors associated with sterilization choices. Design: Multinomial logit regression of sterilization. Patient(s): Various subsamples as appropriate to specific analyses drawn from the 10,847 women interviewed in the 1995 National Survey of Family Growth, and the 5,227 men interviewed in the National Survey of Families and Households. Intervention(s): None. Main Outcome Measure(s): Tubal sterilization and vasectomy. Result(s): Surprisingly high proportions of recent tubal sterilizations were performed on unmarried women: 1 in 3 overall, 1 in 5 among white non-Hispanic women, and 2 in 3 among black women. Sterilization choice among continuously married couples also revealed large differences by race and ethnicity. Parity at the time of the last wanted birth is a major factor affecting sterilization choices, although significant effects were found as well as for a number of other variables, including age differences between spouses, education, and religion. Compared with other regions, the ratio of tubal sterilizations to vasectomies is extremely low in the Western region of the United States. Conclusion(s): Analysis of sterilization decisions must be based on time since the completion of childbearing. The findings call attention to the need for measuring variables that mediate observed associations with sterilization outcomes.
Thermometer placement for oral temperature measurement in febrile adults

BODY temperature is a useful indicator of a person’s state of health when measured accurately and evaluated in the context of related observations about the individual and his environment. Oral temperature measurement is used commonly in clinical settings to screen for febrile states and to document the pattern of fever and whether the course is increasing or diminishing. This study was undertaken to provide additional guidelines for accuracy in oral thermometry technique.
Practical recognition of armored vehicles in FLIR

A practical method for the recognition of armored vehicles in FLIR (forward-looking infrared radar) imagery is presented. This unique method is applied to second-generation IR images of unoccluded vehicles. The principal value of our technique is that recognition is invariant to large changes (up to 45 degrees) in target depth aspect (rotation into or out of the view plane), as well as large changes in range from sensor to target. Feature detection is robust, and is not easily fooled by various irregularities, appendages, and variations among the test targets. This is accomplished by ensuring that certain geometric relationship constraints are satisfied. Various length measurements from target centroid and perimeter are combined into six ratios to supply input features. Such simple, reliable measurements provide low computational complexity, thus having the potential to scale well to larger target sets. Real-time implementation may also be possible. The principal limitation is that, thus far, we have tested the system on less than a dozen different vehicle types. Nevertheless, discrimination between similar-looking vehicles was very high. Also the algorithm works on armored vehicles tha have markedly different appearances (e.g., with or without turrets). Currently our method is reliable with up to 10% shot-noise appearing in the scene. Pattern classification is achieved using an expert system, but this has not been completely automated. We are now using the CLIPS expert system shell, and heuristically coding the various allowable feature ranges. EMYCIN type confidence factors are also being used to give a quantitative measure of classification.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Elm bark derived feeding stimulants for the smaller European elm bark beetle.

The principal feeding stimulants for the beetle Scolytus multistriatus Marsham from the twig bark of Ulmus americana L. have been identified as (+)-catechin-5-β-D-xylopyranoside and lupeyl cerotate.
Renormalized ladder-type expansions for many-particle propagators

For a system of indistinguishable fermions with pairwise interactions, we consider renormalized, perturbative expansions for the three- and four-particle propagators ~Green’s functions ! in terms of exact one-particle propagators, along with a pair interaction that may be bare ~as it appears in the Hamiltonian! or dressed ~polarized!. Care is taken to provide a rigorous foundation for the diagrammatic representations of these perturbation series; in particular, it is demonstrated how each topologically distinct diagram represents an embedding ~in three-dimensional space! of numerous separate terms in the perturbation series. Within a renormalized ladder approximation for the three- and four-particle propagators, we derive diagram weights ~which differ from the two-particle diagram weights! in order to limit the perturbation series to topologically distinct, permutationally independent diagrams. These results lay the foundation for perturbative approximations that decouple the propagator and density matrix equations of motion. DOI: 10.1103/PhysRevA.66.052502
Contribution of proximal promoter elements to the regulation of basal and differential glutathione S-transferase P1 gene expression in human breast cancer cells.

Glutathione S-transferase P1 (GST P1-1) is normally expressed exclusively in estrogen receptor negative (ER−) but not receptor positive (ER+) cultured breast cancer cells. We examined the role of proximal promoter elements in GST P1 gene expression in MCF7 (ER+, GST P1−) and HS578T (ER−, GST P1+) breast cancer cells. Transient transfection of GST P1 promoter–CAT reporter genes confirmed that the GST P1 TRE (−69 to −60) and the adjacent distal GC box (−56 to −51) are required for basal promoter activity in both cell lines. Other studies identified differences in the GST P1 promoter activity and DNA–protein interactions between the two cell lines. Electrophoretic mobility shift assay revealed a protein–TRE interaction that is unique to nuclear proteins derived from GST P1 expressing HS578T cells. Furthermore, a putative silencer region contained within sequences −130 to −70 selectively reduced GST P1 promoter–CAT reporter gene expression in MCF7 but not HS578T cells. While this cell-line specific silencer contributed to the level of GST P1 promoter activity observed in the two cell lines, analysis of cells stably transfected with a novel genomic GST P1 minigene vector established that the silencer is insufficient to completely repress GST P1 transcription in ER+, MCF7 cells that do not normally express endogenous GST P1.
Characterization of the Expression, Intracellular Localization, and Replication Complex Association of the Putative Mouse Hepatitis Virus RNA-Dependent RNA Polymerase

Mouse hepatitis virus (MHV) RNA synthesis is mediated by a viral RNA-dependent RNA polymerase (RdRp) on membrane-bound replication complexes in the host cell cytoplasm. However, it is not known how the putative MHV RdRp (Pol) is targeted to and retained on cellular membranes. In this report, we show that a 100-kDa protein was stably detected by an anti-Pol antiserum as a mature product throughout the virus life cycle. Gradient fractionation and biochemical extraction experiments demonstrated that Pol was not an integral membrane protein but was tightly associated with membranes and coimmunoprecipitated with the replicase proteins 3CLpro, p22, and p12. By immunofluorescence confocal microscopy, Pol colocalized with viral proteins at replication complexes, distinct from sites of virion assembly, over the entire course of infection. To determine if Pol associated with cellular membranes in the absence of other viral factors, the pol domain of gene 1 was cloned and expressed in cells as a fusion with green fluorescent protein, termed Gpol. In Gpol-expressing cells that were infected with MHV, but not in mock-infected cells, Gpol relocalized from a diffuse distribution in the cytoplasm to punctate foci that colocalized with markers for replication complexes. Expression of Gpol deletion mutants established that the conserved enzymatic domains of Pol were dispensable for replication complex association, but a 38-amino-acid domain in the RdRp unique region of Pol was required. This study demonstrates that viral or virus-induced factors are necessary for Pol to associate with membranes of replication complexes, and it identifies a defined region of Pol that may mediate its interactions with those factors.
Fast Space-Varying Convolution Using Matrix Source Coding With Applications to Camera Stray Light Reduction

Many imaging applications require the implementation of space-varying convolution for accurate restoration and reconstruction of images. Here, we use the term space-varying convolution to refer to linear operators whose impulse response has slow spatial variation. In addition, these space-varying convolution operators are often dense, so direct implementation of the convolution operator is typically computationally impractical. One such example is the problem of stray light reduction in digital cameras, which requires the implementation of a dense space-varying deconvolution operator. However, other inverse problems, such as iterative tomographic reconstruction, can also depend on the implementation of dense space-varying convolution. While space-invariant convolution can be efficiently implemented with the fast Fourier transform, this approach does not work for space-varying operators. So direct convolution is often the only option for implementing space-varying convolution. In this paper, we develop a general approach to the efficient implementation of space-varying convolution, and demonstrate its use in the application of stray light reduction. Our approach, which we call matrix source coding, is based on lossy source coding of the dense space-varying convolution matrix. Importantly, by coding the transformation matrix, we not only reduce the memory required to store it; we also dramatically reduce the computation required to implement matrix-vector products. Our algorithm is able to reduce computation by approximately factoring the dense space-varying convolution operator into a product of sparse transforms. Experimental results show that our method can dramatically reduce the computation required for stray light reduction while maintaining high accuracy.
Tibial Tuberosity Realignment Decreases Pressure Applied to Patellofemoral Cartilage

For patients with unrelenting patellofemoral pain, tibial tuberosity realignment procedures are commonly performed to improve patellofemoral alignment and decrease the pressure applied to patellofemoral cartilage. Because malalignment is typically attributed to an excessive lateral force applied to the patella by the quadriceps muscles and the patella tendon, the tibial tuberosity is commonly osteotomized and transferred medially to decrease the lateral force applied by the patella tendon. The tibial tuberosity can also be anteriorized to increase the extensor moment arm of the patella tendon, which decreases the forces applied by the quadriceps muscles during function and subsequently decreases joint compression. Anteriorization and medialization of the tibial tuberosity can also be combined in a single procedure. The goal of the current study was to characterize how medialization, anteriorization and anteromedialization of the tibial tuberosity influence the patellofemoral force and pressure distributions within symptomatic knees. The authors hypothesize that all three realignment techniques decrease the pressure applied to patellofemoral cartilage, but that anteromedialization produces the largest pressure decrease.© 2007 ASME
Online Education of Older Adults and Its Relation to Life Satisfaction.

The purpose of this research was to study the effect of participation in online education on the life satisfaction of the older adult. Life satisfaction was assessed by scores obtained using questions the from Nuegarten, Havighurst, and Tobin (1961) Life Satisfaction Index-A (LSI-A). Other data was obtained using demographic and procedural questions. Raw data suggested that participation in online education can, in fact, increase life satisfaction. However, when results were tested significance was not determined.An implication of the research is that older adults are positively impacted by even minimal exposure to online education.
Conservation Laws in General Relativity as the Generators of Coordinate Transformations

The components of the so-called canonical energy-stress pseudotensor in general relativity may be thought of as the generators of infinitesimal coordinate transformations corresponding to a rigid parallel displacement of the coordinate origin, just as in Lorentz-covariant theories. In this paper it is shown that the canonical expressions, as well as the expressions proposed by Landau and Lifshitz and the expressions for the angular momentum density, are all special cases of an infinity of conservation laws whose pseudovectors generate arbitrary curvilinear coordinate transformations. This approach enables us to construct the transform of every one of these conservation laws under an arbitrary (finite) coordinate transformation. Finally it is shown that every one of these conservation laws may be used to obtain a surface integral relationship that describes the motion of singularities in a general-relativistic theory. It is concluded that there is an infinite number of parameters that describes a singularity of the field, a fact that had previously been in doubt.
TGF‐β: a mobile purveyor of immune privilege

Functionally barricaded immune responses or sites of immune privilege are no longer considered dependent on specific anatomical considerations, but rather, they can develop in any location where immunoregulatory cells congregate and express or release products capable of deviating the host response to foreign antigens. Among the pivotal molecules involved in orchestrating these ectopic sites of immune suppression is transforming growth factor-beta (TGF-beta), a secreted and cell-associated polypeptide with a multiplicity of actions in innate and adaptive immunity. While beneficial in initiating and controlling immune responses and maintaining immune homeostasis, immunosuppressive pathways mediated by TGF-beta may obscure immune surveillance mechanisms, resulting in failure to recognize or respond adequately to self, foreign, or tumor-associated antigens. CD4+CD25+Foxp3+ regulatory T cells represent a dominant purveyor of TGF-beta-mediated suppression and are found in infiltrating tumors and other sites of immune privilege, where they influence CD8+ T cells; CD4+ T-helper (Th)1, Th2, and Th17 cells; natural killer cells; and cells of myeloid lineage to choreograph and/or muck up host defense. Defining the cellular sources, mechanisms of action, and networking that distinguish the dynamic establishment of localized immune privilege is vital for developing strategic approaches to diminish or to embellish these tolerogenic events for therapeutic benefit.
The impact of riverboat casinos on the demand for gambling at casino resorts: a theoretical and empirical investigation

We provide conditions under which a casino resort enjoys an increase in demand following the entry of a riverboat casino in a separate geographical market. Gambling is modeled as an ‘experience good’, whereby consumers are uncertain of the benefit they will receive from the activity prior to engaging in it. The riverboat casino provides nearby consumers with the opportunity to experience gambling without having to incur large transportation costs. Those consumers who discover that they enjoy gambling travel to the casino resort for a vacation next period. Our theoretical results are supported by empirical evidence for casinos in Las Vegas. Copyright © 2001 John Wiley & Sons, Ltd.
A scalar/vector potential formulation of an airfoil in nonuniform stream

A recent innovation in aerodynamic calculation techniques is the formulation based upon scalar and vector potentials (Stokes-Helmholtz decomposition) for the velocity field. This technique is presented: an implementation involving classical panel method is studied. The application of interest is to two-dimensional airfoils moving into a nonuniform approach flow. Comparisons with theoretical and numerical results are included. Furthermore the variations of lift and moment coefficients of quasi-steady simulated flight of an airfoil through microburst wind shear data are studied.
EFFECT OF JEJUNOSTOMY IN EXPERIMENTAL OBSTRUCTION OF THE JEJUNUM OF THE DOG

1. Jejunostomy does not prevent the development of the chemical changes of the blood characteristic of obstruction of the jejunum in the dog. 2. Jejunostomy following experimental obstruction of the jejunum has no beneficial effect upon the duration of life. There is some evidence that life may be shortened by early jejunostomy. 3. Treatment of jejunal obstruction with sodium chloride solution tends to prolong the life of animals regardless of jejunostomy.
Nonlinear optical response in condensed phases: A microscopic theory using the multipolar Hamiltonian

A general scheme is presented for calculating the nonlinear optical response in condensed phases that provides a unified picture of excitons, polaritons, retardation, and local-field effects in crystals and in disordered systems. A fully microscopic starting point is taken by considering the evolution of the quantized radiation-matter system described by the multipolar (µ•D┴) Hamiltonian. For a molecular system with localized electronic states we derive equations of motion in which the instantaneous intermolecular interactions are explicitly recovered and the interaction with the Maxwell electric field is of the µ•E┴ type. It is shown that with total neglect of retardation, these equations lead to the usual expressions for nonlinear optical susceptibilities in terms of equilibrium correlation functions of the polarization field of the molecular system. A mean-field approximation for these equations of motion yields the commonly used local-field expression. Finally, a procedure is proposed for calculating the optical response that fully accounts for retardation, based on a hierarchy of equations of motion for polaritons.
Contamination of cord blood with maternal blood during delivery.

Mixed field agglutination was observed during the ABO grouping of two infants and in the Rh typing of another when using cord blood. Retyping of the babies' blood was performed with blood obtained by heel stick. Kleihauer stains were performed on cord blood smears in two cases. The additional studies revealed that the cord was contaminated with maternal blood in each case. It is postulated that contamination may occur by either of two mechanisms: 1) Maternal blood on the exterior of the umbilical cord may inadvertently drip into the collection container; or 2) during labor maternal blood may enter cord vessels because of retroplacental hemorrhage and rents in the placenta. Cord blood mixed with maternal blood may lead to mistyping of the infant, and because of the absence of preformed alloagglutinins in the newborn misgrouping may not be detected by compatibility testing.
Plasmodium falciparum: effects of membrane modulating agents on direct binding of rhoptry proteins to human erythrocytes.

Abstract We studied the effects of membrane modulation on the interaction of Plasmodium falciparum rhoptry proteins of 140/130/110 kDa (Rhop-H) with human and mouse erythrocytes. Cells treated with 2-(2-methoxyethoxy)ethyl-8-( cis -2- n -octylcydopropyl)octanoate, myristoleyl alcohol, and proteins extracted with sublytic concentrations of membrane solubilizing detergents were used in erythrocyte binding assays. Protein binding was evaluated by immunoblotting using Rhop-H- and SERA-specific antisera, 1B9, K15, and 5E3, respectively. Protein binding to liposomes prepared with dipalmitoyl-L-α-phosphatidylcholine (DPPC) or dilauroyl-L-α-phosphatidylcholine (DLPC) was also examined. Our results show that erythrocyte membrane modulation markedly enhanced direct Rhop-H binding to intact human erythrocytes. Binding of SERA to intact human erythrocytes appeared unaffected. Both DPPC and DLPC liposomes had similar Rhop-H and SERA protein binding activities. However, binding to DLPC liposomes was reduced. Rhop-H and SERA extracted with the detergents octanoyl- N -methylglucamide, decanoyl- N -methylglucamide, sodium deoxycholate, and 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate bound directly to intact human erythrocytes, probably by partitioning hydrophobically into the membranes. Sodium carbonate treatment demonstrated a nonintegral association of Rhop-H with the erythrocyte membrane during invasion. Membrane modulation may expose cryptic phospholipid binding sites in the bilayer.
Hydrazine-mediated DNA damage: role of hemoprotein, electron transport, and organic free radicals.

The hydrazines represent an important class of xenobiotic agents encountered in the environment, in industrial settings, and in medical therapeutics. Agents with a hydrazine functionality are metabolized to toxic intermediates capable of damaging cellular macromolecules and stimulating proteolysis. Phenylhydrazine (PH), methylhydrazine (MH), hydrazine (HY), and the therapeutic agents phenelzine (PZ) and hydralazine (HD) were examined for their ability to undergo metabolism via HbO2 and to cause damage to added supercoiled phi x174 RF DNA. The hydrazines, when incubated in hemolysate, caused a time- and concentration-dependent strand scission of DNA as monitored using phi x174 RF DNA. The rank order for hydrazine-mediated damage was phenylhydrazine > phenelzine > hydrazine > hydralazine > methylhydrazine. In addition, hydrazine-mediated damage to DNA increased in proportion to protein concentration (i.e., HbO2 content) of the hemolysate. To examine whether the DNA damage resulted primarily from organic free radicals or reactive oxygen free radical species, a series of mechanistic studies employing antioxidants and a free radical scavenger was initiated. The antioxidants dimethylfuran, dimethyl sulfoxide, and dimethylthiourea failed to inhibit hydrazine-mediated DNA damage in hemolysate. In contrast, the free radical spin trap agent dimethylpyrrolidin-N-oxide effectively inhibited PH-mediated DNA damage, while the free radical scavenger N-acetylcysteine also showed a protective effect against PH-, PZ-, HD-, HY-, and MH-mediated DNA strand scission. Potassium ferricyanide-mediated methemoglobin formation and imidazole, a ligand for the heme moiety of hemoglobin, both inhibited PH-stimulated DNA damage in hemolysate demonstrating the importance of oxyhemoglobin to the process. These results suggest that organic free radicals play a dominant role, relative to oxygen free radical species, in hydrazine-mediated DNA strand scission.
Mary Tudor, Lord Morley, and St. Thomas Aquinas: The Politics of Pious Translation at the Henrician Court

Sometime in 1527 an eleven-year-old Mary Tudor translated a prayer by St. Thomas Aquinas (Concede mihi) from Latin into English. Although Henry Parker, Lord Morley attests to the fact that Mary's t...
Nuclear chromatin changes in hepatocytes of soman treated rats.

Abstract Cytochemical and morphometric indices of DNA metabolism and nuclear transcriptional-translational capabilities were used to monitor liver responses in Sprague-Dawley × Wistar rats subcutaneously injected with 0.9 LD 50 soman, a highly toxic acetylcholinesterase-inhibiting organophosphate. Thirty minutes post-soman the following were evident: (1) increased polyploidization; (2) expansion of the nuclear envelope; and (3) elevated deoxyribonucleoprotein (DNP) complex lability to acid hydrolysis. Nuclear changes were accompanied by cytoplasmic correlates of impaired hepatocyte function, i.e., vacuolation and depressed basophilia. The overall data suggest that with acute soman toxication there are concomitant adaptive and maladaptive responses occurring within liver parenchymal elements. It is postulated that nuclear changes represent an early proliferative response and DNP activation to enhance detoxification capabilities, whereas cytoplasmic changes reflect the disruption of normal function and hepatotoxic injury.
The relationship between spectral sensitivity and spatial sensitivity for the primate r-g X-channel.

Which visual channel detects high spatial frequencies during careful fixation? Color vision models based on psychophysical data contradict electrophysiological results. According to electrophysiology, the channel which mediates foveal acuity originates in the small, tonic color-opponent r-g units of the X-cell pathway. However, psychophysical models assign acuity to theVλ channel because when acuity is used as a criterion for equating luminosity it is additive. In all opponent-color models the r-g channel is subadditive and hence is excluded from mediating acuity. We show that the r-g channel adds cone signals for high spatial frequencies and subtracts them for low, and conclude that the major achromatic channel for human foveal vision originates within the r-g color-opponent channel. Quantitative analysis makes explicit the interaction between the spatial and spectral variables for the simple-opponent cells which predominate in primate foveal vision.
How I Learned to Have a Heart

Seasoned teachers know how important relationships are in the classroom. This includes students' relationships with one another, but also teachers' relationships with each individual student. It to...
Software engineering for web services workflow systems

Service-oriented computing (SOC) suggests that many open, network-accessible services will be available over the Internet for organizations to incorporate into their own processes. Developing new software systems by composing an organization's local services and externally-available web services is conceptually different from system development supported by traditional software engineering lifecycles. Consumer organizations typically have no control over the quality and/or consistency of the external services that they incorporate, thus top-down software development lifecycles are impractical. Software architects and designers will require agile, lightweight processes to evaluate tradeoffs in system design based on the "estimated" responsiveness of external services coupled with known performance of local services. We introduce a model-driven software engineering approach for designing systems (i.e. workflows of web services) under these circumstances and a corresponding simulation-based evaluation tool.
The Patient Centered Medical Home as Curricular Model: Perceived Impact of the “Education-Centered Medical Home”

Background The patient-centered medical home (PCMH) model aims to provide patient-centered care, lower costs, and improve health outcomes. Medical students have not been meaningfully integrated in this model.
Inefficient vaginal transmission of tenofovir resistant HIV-1

Transmission of drug-resistant HIV has been postulated to be a threat to current first-line antiretroviral therapy (ART) regimens and the efficacy of several antiretroviral-based preexposure prophylaxis (PrEP) strategies being tested. Here we evaluated the effect of the common tenofovir (TFV) resistance mutation K65R on vaginal HIV transmission. Our results demonstrate that despite no overt loss of overall replication competence in vivo, this mutation results in significantly reduced mucosal transmission. When transmitted, the mutant virus eventually reverted to the wild type in 2 of 3 animals examined.
Spin-flip configuration interaction: an electronic structure model that is both variational and size-consistent

A new formulation of the configuration interaction (CI) method is presented. It is based on the recently introduced spin-flip (SF) approach. SF-CI target states are described as spin-flipping excitations from the reference Hartree–Fock high-spin, e.g., Ms=1 (|αα〉), determinant. The resulting model is both variational and size-consistent. Moreover, the SF-CI model can describe within a single-reference formalism some inherently multi-reference situations, such as single bond-breaking and diradicals. Initial benchmarks for the SF-CI model with single and double substitutions (SF-CISD) are presented.
Temperature dependence of the graybody approximation to emissivity for some common materials

Modern infrared imaging radiometric cameras typically measure over a nominal waveband within one of two atmospheric windows, 8-12 or 3-5 micrometers. As such, they must assume targets are graybodies to calculate their temperatures. The IR camera can be used to measure target emissivity, enhancing the integrity of the graybody approximation, at least near the temperature at which the emissivity was measured. For realbodies, spectrally nonuniform emitters, the graybody emissivity approximation will be temperature dependent. This paper models the graybody emissivity temperature dependence for a variety of materials whose emissivity may be easily measured near room temperature whilst the application temperatures may be several hundred degrees Celsius.
An exploratory study of a risk neutral pricing model of accumulators

Purpose – Accumulators are cutting‐edge stock derivative investments that have been the subject of much controversy in Hong Kong over the past year. Accumulators are exotic options composed of a full year of daily long up‐and‐out call options and short up‐and‐out put options. Because accumulators are so new, the understanding of accumulators is currently very limited. This paper attempts to characterize and understand the properties of this fairly unknown and new stock derivative investment.Design/methodology/approach – The study analyzed and characterized accumulators based on observations from past history of 11 stocks of the Hang Seng Index. Using historical stock data covering from January 3, 2006, and onward, the profit and loss for each accumulator contract was calculated.Findings – Through the research it is understood that the profit and loss of accumulator contracts depends primarily on the following factors: knockout percentage, discount percentage, variability of the underlying stock, and the o...
Thermal emission of holes from defects in uniaxially stressed p-type silicon.

Iron-acceptor pair defects in silicon are insensitive to stress. These defects therefore provide convenient reference points from which to measure the effects of uniaxial stress on the valence-band structure in silicon. Despite the strong mixing of light- and heavy-hole bands at low values of stress, we find that for thermal emission the stress-split valence band can be approximated as two independent bands that displace rigidly with increasing stress according to the shear deformation potentials. The spherical approximation for the effective masses is not consistent with these deformation potentials because the approximation incorrectly partitions the density of states between the two bands. We establish the correct partitioning of the density of states numerically, and find stress-dependent density of states that approximately conserve the center of gravity of the split valence bands. Uniaxial stress data on the Fe-Al defects in silicon are used to experimentally verify the numerical results. The analysis described in this paper can be easily generalized to determine the stress properties of hole traps in any p-type semiconductor.
Inhibition of endocytosis by anti-clathrin antibodies

We examined the function of clathrin, a cytoplasmic protein associated with coated pits and vesicles, by introducing monoclonal antibodies into living cells and determining their effects on membrane transport. When anti-clathrin heavy chain antibodies were used, the following effects were observed: clathrin became aggregated in the cytoplasm, the number of coated pits on the plasma membrane was reduced, and adsorbtive endocytosis of Semliki Forest virus and fluid-phase endocytosis were decreased by 40%-50%. No change in transport of newly synthesized influenza hemagglutinin to the plasma membrane was observed. The results indicated that clathrin in CV-1 cells is involved in fluid-phase uptake and receptor-mediated endocytosis, but not in constitutive transport within the secretory pathway.
Correlation of the Charge Storage and Magnetic Susceptibility of Hydrous RuO2

Hydrous RuO2 is a mixed metallic-protonic conductor that is used as a charge storage material in electrochemical capacitors and as an electrocatalyst. Previous structural analysis by Dmowski, et. al. has shown that RuO2 is a composite of ordered RuO2 nanoparticles that are surrounded by hydrous grain boundaries. In this paper, magnetic susceptibility (MS) is used to show that the hydrous RuO2 has both localized and delocalized electrons. The localized electrons are attributed to Ru3+ defects that decrease in concentration with decreasing water content. The delocalized electrons are represented by a temperature independent paramagnetic (TIP) component of the MS. The magnetic data is consistent with a structure having metallic nanoparticles whose electrons become more itinerant with decreasing structural water. We conclude that hydrous RuO2 stores charge analogously to double-layer capacitors in which charge is stored at the interface of the hydrous grain boundaries and the metallic nanoparticles, and that there is effectively no difference in the charge storage mechanisms of hydrous RuO2 and carbon.
Skill Level and Efficacy of Effector Visual Feedback in Ball Catching

The importance of visual feedback of the catching arm in a one-handed catching task and the interaction of that feedback with skill level was investigated. 10 male and 10 female subjects were separated into skilled or unskilled groups based on previous experience. Seated subjects attempted to catch 20 balls projected from a ball-projection machine aimed near the right shoulder. During half of these trials, the subject's vision of the catching arm was prevented by a screen which still permitted viewing of the critical portion of the ball's trajectory. All trials were recorded on video to identify the catching errors as errors of position or grasping. Skilled subjects made fewer errors than unskilled subjects. Occluding vision of the catching arm resulted in more errors, specifically more position errors. This finding was true for both skilled and unskilled subjects, indicating that both groups process information, visual and proprioceptive, in a qualitatively similar fashion in this task.
Physiological evidence that the 2-deoxyglucose method reveals orientation columns in cat visual cortex.

A method for measuring local rates of glucose uptake in mammalian brain tissue1,2 has been used to study monkey cortex receiving visual stimulation through one eye3. The resulting pattern of glucose uptake resembled that of the ocular dominance columns, identified by several independent methods in the cortex4–6. In addition, the pattern of glucose uptake produced by binocular viewing of stripes of a single orientation7–12 was consistent with the arrangement of orientation columns expected from the sequence of preferred orientations of single cells recorded in the visual cortex4,13–16. It was therefore assumed that the columns of glucose uptake revealed in the studies of orientation selectivity correspond to columns of cortical cells selective for the orientation viewed. Recent findings about the monkey visual cortex led us to question this assumption.17–20 We have now investigated this question in the cat by making microelectrode recordings to determine preferred orientation of cortical units at known positions within the visual cortex and then stimulating the same animals with a full-field pattern of stripes to measure the rates of glucose uptake at the positions of each of the cortical units. As in previous studies, preferred orientation shifted gradually and progressively along electrode tracks parallel to the cortical surface4,13–16 and a pattern of densely labelled columns was observed in the 2-deoxyglucose autoradiographs7–12. The centres of densely labelled cortical columns contained cells selective for the stimulated orientation. Preferred orientation shifted gradually away from the stimulated orientation at sites progressively more distant from the centres of the columns. Control experiments revealed no columns after stimulation with a pattern of changing orientation. Thus the columns revealed by the deoxyglucose method do correspond to the physiological orientation columns.