cssi/SciSciGPT-SciSciNet huggingface dataset:
Predictors of post-mastectomy reconstruction in an underserved population.

Summary Objective Past studies found insurance status, race, comorbidities and hospital setting influence the likelihood and timing of post-mastectomy breast reconstruction (BR). We evaluated these factors at a public hospital serving a predominantly minority and uninsured population. Methods Women who underwent mastectomy and/or BR from 2005 to 2011 were reviewed. The association between patients' characteristics and receipt of BR and timing (immediate BR vs. delayed BR) were analyzed. The 5-year overall BR rate was estimated with the Kaplan–Meier method. Results The analysis included 387 patients. 130 received BR. 85 (65%) received immediate BR and 25 (19%) underwent microsurgical repair. The total complication rate was 25%. The 5yr overall BR rate was 43% (95% CI: 36%–51%). Univariate factors positively associated with overall BR included younger age, non-smoker, lower BMI, no comorbidities, no neoadjuvant chemotherapy requirement, lower AJCC stage and negative lymph nodes. Younger age, no comorbidities, neoadjuvant chemotherapy, higher AJCC stage, and positive lymph nodes were positively associated with delayed breast reconstruction compared to immediate BR. Multivariate regression models show patient of younger age ( p p p p p Conclusion At a public hospital, serving a largely uninsured population, post-mastectomy rates of immediate BR and overall BR within 5 yrs are 22% and 43%, respectively. Overall complication rates were low and a substantial fraction of post-mastectomy patients received microsurgical BR. Contrary to previous studies, race and insurance status were not found to be the primary drivers of post-mastectomy reconstruction.
Promoter mutations affecting divergent transcription in the Tn10 tetracycline resistance determinant.

Abstract The tetracycline resistance determinant in transposon Tn10 consists of two genes, the tetA resistance gene and the tetR repressor gene, that are transcribed from divergent overlapping promoters. We determined the levels of pulse-labeled tet messenger RNA in Escherichia coli strains with the Tn10 tet genes on a multicopy plasmid. Addition of the inducer 5a,6-anhydrotetracycline results in a 270- to 430-fold increase in tetA mRNA and a 35- to 65-fold increase in tetR mRNA. As judged by the relative molar amounts of tetA and tetR mRNA synthesized under maximally inducing conditions, the tetA promoter (tetPA is 7 to 11 times more active than the two tetR promoters (tetPR1 and tetPR2) combined. We characterized ten mutations in tetPA, including nine single-base-pair substitutions and a 30-base-pair deletion. All of the single-base-pair changes reduce the agreement with the consensus sequence for promoters recognized by E. coli RNA polymerase. Mutations in highly conserved nucleotides result in a 200- to 600-fold reduction in tetPA activity in vivo. Unexpectedly, tetPA mutations reduce by two- to fourfold the combined activity in vivo of tetPR1and tetPR2, in spite of their locations outside the −35 and −10 regions of tetPR1 and tetPR2. For two tetPA mutations, the negative effect on tetPR activity was also demonstrated in tetR− tetRR-lacZ operon fusion strains, thus eliminating the possibility that it is due to variations in either plasmid copy-number or induction efficiency. The pleiotropic effects of tetPA mutations are discussed in terms of the expectation that the overlapping tet promoters compete for RNA polymerase.
The Fiber Walk: A Model of Tip-Driven Growth with Lateral Expansion

Tip-driven growth processes underlie the development of many plants. To date, tip-driven growth processes have been modeled as an elongating path or series of segments, without taking into account lateral expansion during elongation. Instead, models of growth often introduce an explicit thickness by expanding the area around the completed elongated path. Modeling expansion in this way can lead to contradictions in the physical plausibility of the resulting surface and to uncertainty about how the object reached certain regions of space. Here, we introduce fiber walks as a self-avoiding random walk model for tip-driven growth processes that includes lateral expansion. In 2D, the fiber walk takes place on a square lattice and the space occupied by the fiber is modeled as a lateral contraction of the lattice. This contraction influences the possible subsequent steps of the fiber walk. The boundary of the area consumed by the contraction is derived as the dual of the lattice faces adjacent to the fiber. We show that fiber walks generate fibers that have well-defined curvatures, and thus enable the identification of the process underlying the occupancy of physical space. Hence, fiber walks provide a base from which to model both the extension and expansion of physical biological objects with finite thickness.
Evidence for an alteration in the microsomal Ca2+ release mechanism in senescent rat parotid acinar cells

Previously, we have shown that Ca2+ mobilization following an α1-adrenergic receptor stimulus is reduced in parotid acinar cells from senescent rats as a result of an altered ability of inositol 1,4,5-trisphosphate (IP3) to induce Ca2+ release from a non-mitochondrial, intracellular Ca2+ store (Ishikawa, Y., et al. Biochim. Biophys. Acta 968, 203–210). We have used this model to examine the IP3-induced Ca2+ release mechanisms in these cells. 45Ca2+ efflux, after exposure to (−) epinephrine, from cells of young adult (3–6 months) rats was approx. 2-fold that observed from cells from older animals (approx. 24 months) either in the presence or absence of extracellular Ca2+. Similarly, cytosolic Ca2+ levels were greater in cells of young adult rats under these same incubation conditions. However, microsomal membrane preparations, from both age groups displayed similar IP3 binding sites (Kd ≈ 90nM, Bmax ≈ 850fmol/mg protein) and ATP-dependent Ca2+ transport ability (approx. 8 nmol/mg protein·min−1). These data suggest that there is an alteration in the IP3-induced Ca2+ release mechanism in microsomal membranes of parotid glands from senescent rats which may account for the decreased Ca2+ release seen after agonist stimulation of this tissue.
Curvature is a Basic Feature for Visual Search Tasks

A curved target can be found efficiently among straight distractors in a visual search task. This could reflect the status of curvature as a basic feature for visual search. Alternatively, curvature could be detected as a locus of high variation in orientation. In a series of experiments it is shown that efficient search for curvature is possible even if local variation in orientation is eliminated as a cue. This suggests that curvature is part of the set of basic features for visual search and that this set is derived relatively late in the course of visual processing.
Modeling of residual stress distribution in D2 steel via grinding dynamics using a second-order damping system

Abstract A second-order system is proposed to model residual stress distributions in D2 tool steel under various heat treatment procedures and grinding dynamics. The study was motivated to predict the magnitude of the residual stress, tensile peak location, and to establish the nonlinear superposition relationship in the residual stress distribution due to the number of grinding passes. The grinding dynamics was represented as a lumped system composed of a spring-mass-damper of the grinding machine and a damper-stiffness of the workpiece. A nested factorial experiment of 18 conditions with 3 levels of tempering, 2 levels of grinding conditions and 3 multipass grinding levels was used for the model development and validation. The parameters of each condition were then optimized by using auto-regressive system identification. The proposed model depicts changes of the complex experimental treatment conditions and estimates in a precise and parsimonious way the corresponding change in the subsurface residual stress distribution. With only one parameter involved, the model facilitates conceptual progress in the residual stress superposition; the prediction elucidates grinding dynamics and supports a theory of the heat treatment and grinding effects on the material characteristics.
Improving the Navigability of a Hexapod Robot using a Fault-Tolerant Adaptive Gait

This paper encompasses a study on the development of a walking gait for fault tolerant locomotion in unstructured environments. The fault tolerant gait for adaptive locomotion fulfills stability co...
Hitting probabilities and polar sets for fractional brownian motion

Let be the d-dimensional fractional Brownian motion with index . The upper and lower bounds on the hitting probabilities of X(t) are obtained. Sufficient conditions for a compact set to be a polar set for X(t) are proved. It is also proved that if N≤αd, then for any compact set and if N<αd, then for any compact set where B(R d ) denotes the Borel σ-algebra in R d , and where dim and Dim are HausdorfT dimension and packing dimension respectively
The halo effect: It is a unitary concept! A reply to Fox et al. (1983)

Fox et al. (1983) concluded that halo is not a unitary concept. This paper argues that their conclusion is erroneous and that it is based on a misunderstanding of the role of variance in statistical analysis, a mistaken use of ANOVA to calculate halo, and the confusion of those analyses that measure the similarity in ratings across raters with those that compare the similarities in ratings under different rating conditions.
Layer-by-layer etching of Si(100)-2 x 1 with Br2: A scanning-tunneling-microscopy study.

Layer-by-layer etching of Si(100)-2×1 at 900 K with Br 2 has been studied with scanning tunneling microscopy. Preferential etching of S B (ragged) step edges dominates at low Br 2 exposures but etch pits that are one layer deep (vacancy islands) also appear on the terraces. The elongated shapes of the vacancy islands indicate that etching proceeds at a much faster rate along the dimer row direction than perpendicular to it. Chains and two-dimensional islands due to Si regrowth appear on the terraces. With increased exposure, the vacancy islands form networks on the terraces and become connected to step edges
Identifying Linkages Between Land Use, Geomorphology, and Aquatic Habitat in a Mixed-Use Watershed

The potential impacts of land use on large woody debris (LWD) were examined in Sourdough Creek Watershed, a rapidly growing area encompassing Bozeman, Montana, USA. We identified six land classes within a 250 m buffer extending on either side of Sourdough Creek and assessed aquatic habitat and geomorphologic variables within each class. All LWD pieces were counted, and we examined 14 other variables, including undercut bank, sinuosity, and substrate composition. LWD numbers were generally low and ranged from 0 to 8.2 pieces per 50 m of stream. Linear regression showed that LWD increased with distance from headwaters, riparian forest width, and sinuosity in four of the six land classes. Statistically significant differences between land classes for many aquatic habitat and geomorphologic variables indicated the impacts of different land uses on stream structure. We also found that practices such as active wood removal played a key role in LWD abundance. This finding suggests that managers should prioritize public education and outreach concerning the importance of in-stream wood, especially in mixed-use watersheds where wood is removed for either aesthetic reasons or to prevent stream flooding.
Adverse Selection and Pay Compression

A fundamental result of the principal-agent literature is that pay will be linked to performance when it is difficult for the principal to monitor the agent's actions. However, performance pay can lead to adverse incentives. In these models, high-powered incentives encourage workers to neglect some aspects of their job or to sabotage their coworkers' efforts. This paper offers another explanation for the weak link between pay and performance: worker heterogeneity. When workers are heterogeneous and labor contracts are contests, the Nash equilibrium often pools workers. I show that this implies that the link between pay and performance is weaker than would be the case if firms could observe workers' types before contracting and offer each type their respective optimal contests. A fundamental result of the principal-agent literature is that pay will be linked to performance when it is difficult for the principal to monitor the agent's actions. But in the real world, we often find this link to be weak. Several authors (Lazear 1989; Holmstrom and Milgrom 1991; Garvey and Swan 1992) have shown that weaker incentives may be optimal when performance pay leads to undesired behavior on the part of workers. In Lazear's tournament model, firms weaken the link between pay and performance when workers can sabotage their coworkers' efforts. Holmstrom and Milgrom show that straight salaries are optimal when the worker's job includes some activities that cannot be easily monitored. And Garvey and Swan show that a hybrid compensation scheme that is part tournament and part managerial discretion is optimal when workers can sabotage coworkers' efforts and managers face adverse incentives. The common thread in these papers is that principals weaken the link between pay and performance to mitigate adverse incentives.' This is what Garvey and Swan call "pay compression." In this paper, I show that adverse incentives, while sufficient, are not necessary for pay compression to occur. I consider a labor market where workers are heterogeneous with respect to ability (measured as cost of effort, with more able workers having a lower cost of effort), jobs have a single
Non-covalent interactions between unsolvated peptides: helical complexes based on acid-base interactions.

We have used ion-mobility mass spectrometry to examine the conformations of the protonated complex formed between AcA 7 KA 6 KK and AcEA 7 EA 7 , helical alanine-based peptides that incorporate glutamic acid (E) and lysine (K). Designed interactions between the acidic E and basic K residues help to stabilize the complex, which is generated by electrospray and studied in the gas phase. There are two main conformations: (1) a coaxial linear arrangement where the helices are tethered together by an EKK interaction between the pair of lysines at the C-terminus of the AcA 7 KA 6 KK peptide and a glutamic acid at the N-terminus of the AcEA 7 -EA 7 peptide and (2) a coiled-coil arrangement with side-by-side antiparallel helices where there is an additional EK interaction between the E and K residues in the middle of the helices. The coiled-coil opens up to the coaxial linear structure as the temperature is raised. Entropy and enthalpy changes for the opening of the coiled-coil were derived from the measurements. The enthalpy change indicates that the interaction between the E and K residues in the middle of the helices is a weak neutral hydrogen bond. The EKK interaction is significantly stronger.
USEFULNESS OF WELL REGISTRATION DATA

. This investigation was to determine whether data on irrigation-well registration forms as reported by well drillers can be used in hydrologic studies. Transmissivity maps were prepared for Hamilton County, Nebraska using only specific capacity values computed from yield and drawdown data, as reported on irrigation well-registration forms. On one map each control point was the mean of the transmissivity values calculated for all wells in a section. On a second map each control point was the mean of the means for four contiguous sections sharing a common corner. The second map was similar to that of a previously prepared map based on control point values computed from specific capacities of selected wells, test hole logs, and geologic interpretations. These results suggest that reported registration data for a given area have a normal population distribution. In situations where individual data are unverified the data base can be treated as samples of a population where the mean of the means of several samples for adjacent areas is representative of actual field conditions.
The role of Brinkman viscosity in poroacoustic propagation

Abstract Through perturbation analysis, we study the role of Brinkman viscosity in the propagation of finite amplitude harmonic waves. Interplay between various parameters, namely frequency, Reynolds number and beta, is investigated. For systems with physically realizable Reynolds numbers, departure from the Darcy Jordan model (DJM) is noted for high frequency signals. The low and high frequency limiting cases are discussed, and the physical parameters defining the acoustic propagation are obtained.
Numerical simulation of steady supersonic flow over an ogive-cylinder-boattail body

A recently reported parabolized Navier-Stokes code has been employed to compute the supersonic flow field surrounding an ogive-cylinder-boattail body at incidence. The computations were performed for flow conditions where an extensive series of experimental surface pressure and turbulent boundary-layer profile measurements had been obtained. Comparison between the computational results and experimental measurements for angles of attack up to 6 deg show excellent agreement. At angles greater than 6 deg discrepancies are observed which are tentatively attributed to three-dimensional turbulence modeling errors.
A rapid purification of proteolipid protein adaptable to large quantities

Abstract By means of two solvent treatments and two gel-permeation treatments, a crude total lipid extract can be processed in quantity to obtain pure proteolipid protein which retains its characteristic property of being soluble in CHCl3CH3OH mixtures and is freed of adventitious lipids.
Qualitative and Quantitative High Performance Liquid Chromatographic Analysis of Quassinoids in Simaroubaceae Plants

A convenient and reliable reversed phase high performance liquid chromatography method was developed using a phenyl column and gradient elution for the determination of eight important quassinoids including glaucarubolone, chaparrinone, holacanthone, glaucarubinone, picrasin B, paraine, neoquassin and quassin, in diverse tissues of species of the Simaroubaceae. The method gave well resolved peaks for these compounds with good response and linearity in the range of 25–1000 ng. Incorporation of an internal standard provided easy quantitation of the quassinoids.
Hydrodynamic Forces on Spillway Torque-Tube Gates

The critical hydraulic configuration for a set of torque-tube gates controlling the flow through the navigable portion of a spillway was experimentally identified. In this paper, an analytical model for the upstream pressure field on a typical gate within the set is constructed. The gate rotation from the maximum elevation (gate in closed position) and the hydraulic torque transmitted by the pressure field to the gate tube are formulated. Mean values of parameters of response are often sufficient for the preliminary design of a gate. The dispersions of these parameters of response, which are necessary for the final design of a gate, may be computed using the corresponding mean-square values. These were obtained empirically in a flume from experiments on a 1/15-scale physical model of a set of three prototype gates for the Montgomery Point Lock and Dam project. Theoretical predictions of parameter mean and mean-square values compare well with the average corresponding statistics obtained experimentally.
Chemical regulation of alfalfa/grass mixtures with imazethapyr

(...) A field experiment was conducted for 2 yr to investigate the effects of applications of imazethapyr [5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl) nicotinic acid] on production and quality of alfalfa (Medicago sativa L.)/grass mixtures. Mixtures of alfalfa with either orchardgrass (Dactylis glomerata L.), ryegrass (Lolium perenne × L. multiflorum Lam), reed canarygrass (Phalaris arundinaceae L.), smooth bromegrass (Bromus inermis Leyss)., or timothy (Phleum pratense L.) were established on a Hagerstown silt loam (fine, mixed, mesic Typic Hapludalf) and were treated with imazethapyr at application rates of 0, 25, 50, and 100 g a.i. ha −1 .(...)
Three-dimensional image reconstruction in variable density acoustic tomography

Diffraction tomography (DT) is an established imaging technique for use with diffracting wavefields, which represents a generalized form of x-ray tomography. In this work, we revisit the three-dimensional reconstruction problem of DT for variable density acoustic media. Novel reconstruction algorithms are developed for reconstructing separate images that depict a weakly scattering object's compressibility and density variations. If tomographic measurement data are acquired at four distinct temporal frequencies, we demonstrate that the effects of object dispersion can be accounted for completely by use of analytic reconstruction formulas. Computer-simulation studies are conducted to demonstrate the developed image reconstruction methods.
Utilization of Hydrolyzed Sucrose Polyester (Olestra) in Broiler Diets

Abstract Three experiments were conducted in which hydrolyzed olestra (HO) and hydrolyzed olestra manufacturing by-product (HBP) were compared with corn oil (CO) and a feed-grade hydrolyzed animal-vegetable fat blend (AVF) as fat supplements in diets for broilers. Various blends of HO and HBP with AVF and other fat sources were also evaluated. Results of these experiments indicate that HO or HBP may be used as energy sources in broiler diets. Use of these materials as the sole source of supplemental fat often reduced body weight gain and impaired feed utilization as compared with CO or AVF; however, when used as a component of a blended fat product typical of industry supplements, there was little if any adverse effect on live performance. Carcass fatty acid content was a reflection of dietary fat content. If the blend of fats containing HO or HBP contains a suitable ratio of unsaturated and saturated fatty acids, the product should be an acceptable source of supplemental energy in broiler diets.
Anisotropic photonic crystal building blocks: colloids tuned from mushroom-caps to dimers

Nonspherical polystyrene particles tuned from collapsed spheres (mushroom cap and hemisphere shapes) to two-lobed dimers are synthesized by seeded emulsion polymerization. The presence of a swelling solvent and additions of divinylbenzene crosslinker facilitate shape control through directing phase separation of the polymer network and the monomer in the swollen particles as well as the solvent release behavior. Confocal microscopy of the particles, dyed in the initial swelling and polymerization stage followed by a second stage, differentiates the locations of effective seeds and second stage polymerized material which dictate the external particle morphology. The anisotropic particles are prepared in sufficient quantity and uniformity to self-organize into colloidal crystal and rotator structures, as is demonstrated with a mushroom cap-shaped particle system condensed under confinement. Structural transitions follow the drive to maximize packing efficiency at systematically varied confinement heights. Confocal microscopy confirms monolayer, buckled and bilayer thin films with unconventional orientational ordering.
Friendships in Childhood and Adolescence: The Life Course and New Directions*

Contemporary sociologists and psychologists have long been interested in youth friendship, and have generated a large but disconnected body of literature on this topic. In this essay, I advocate using life course theory to weave together the varied elements of this literature and to generate new lines of research for the next millennium. First, I survey four general themes of contemporary research: friendship and development, the nature and structure of friendship, friendship culture, and the social context of friendship. Second, I explore how life course theory can bridge sociological and psychological research by viewing friendship as shaped by sociohistorical forces and as regulating human development. Four general issues are discussed: pathways and trajectories, the social embeddedness of relationships, long-term perspectives on friendship, and methodological issues pertinent to life course treatments of friendship. By drawing on life course principles, future researchers can advance understanding of the role of friendship in young people's lives.
Optimal realizable networked controllers for networked systems

In this paper, we provide the optimal solution for the H 2 control problem in the case when both plant and controller are interconnected systems interacting over an arbitrary directed causal network. We first analyze the structure of network realizable systems and then characterize the set of all stabilizing controllers that are realizable over the given network using the Youla parametrization. The H 2 control problem is then cast as a convex optimization problem and its solution is shown to provide the optimal distributed controller over the given network. The results of this paper allow one to apply many classical results and approaches of multi-variable robust control to networked systems.
INFLUENCE OF GLUTARALDEHYDE AND/OR OSMIUM TETROXIDE ON CELL VOLUME, ION CONTENT, MECHANICAL STABILITY, AND MEMBRANE PERMEABILITY OF EHRLICH ASCITES TUMOR CELLS

Effects of fixation with glutaraldehyde (GA), glutaraldehyde-osmium tetroxide (GA-OsO4), and osmium tetroxide (OsO4) on ion and ATP content, cell volume, vital dye staining, and stability to mechanical and thermal stress were studied in Ehrlich ascites tumor cells (EATC). Among variables investigated were fixation time, fixative concentration, temperature, osmolality of the fixative agent and buffer, total osmolality of the fixative solution, osmolality of the postfixation buffer, and time of postfixation treatment in buffer (Sutherland, R. M., et al. 1967. J. Cell Physiol. 69:185.). Rapid loss of potassium, exchangeable magnesium, and ATP, and increase of vital dye uptake and electrical conductivity occurred with all fixatives studied. These changes were virtually immediate with GA-OsO4 or OsO4 but slower with GA (in the latter case they were dependent on fixative temperature and concentration) (Foot, N. C. 1950. In McClung's Handbook of Microscopical Technique. 3rd edition. 564.). Total fixative osmolality had a marked effect on cell volume with OsO4 but little or no effect with GA or GA-OsO4. Osmolality of the buffer had a marked effect on cell volume with OsO4, whereas with GA or GA-OsO4 it was only significant at very hypotonic buffer osmolalities. Concentration of GA had no effect on cell volume. Osmolality of the postfixation buffer had little effect on cell volume, and duration of fixation or postfixation treatment had no effect with all fixatives. Freezing and thawing or centrifugal stress (up to 100,000 g) had little or no effect on cell volume after all fixatives studied. Mechanical stress obtained by sonication showed that OsO4 alone produced poor stabilization and that GA fixation alone produced the greatest stabilization. The results indicate that rapid membrane permeability changes of EATC follow fixative action. The results are consistent with known greater stabilizing effects of GA on model protein systems since cells were also rendered relatively stable to osmotic stress during fixation, an effect not noted with OsO4. After fixation with GA and/or OsO4 cells were stable to osmotic, thermal, or mechanical stress; this is inconsistent with several earlier reports that GA-fixed cells retain their osmotic properties.
Lasting Welfare Effects of Widowhood in Mali

Summary Widows and their children are largely hidden from view in the data used to inform social policy discussions in Africa. Data for Mali reveal that households headed by widows have significantly lower living standards than other households in rural and urban areas. Furthermore, the welfare difference persists even after widows are absorbed into male headed households. An examination of individual measures of well-being further reveals that, relative to other women, worse outcomes for ever-widowed women persist through remarriage. These detrimental effects are passed on to children, suggesting an intergenerational transmission of poverty stemming from widowhood.
Rapid and Accurate Determination of Stern-Volmer Quenching Constants

In this work, a novel system has been designed, characterized, and validated for the determination of fluorescence quenching constants. Capillary flow injection methods are used to automate the preparation and mixing of the fluorophore and quencher solutions. Because of the small diameter of the capillary (75-200 mu m), fluorescence measurements can be made without corrections for primary and secondary absorbance effects. The fluorescence spectrometer is equipped with a charge-coupled device (CCD) that has a detection limit of 3.0 X 10-9 M (2.3 ppb) and a linear dynamic range of 10 5 for integration times of 0.01-10 s. This spectrometer has a 300 nm spectral range with 1 nm resolution, allowing the fluorescence quenching constants to be calculated at single wavelengths or over integrated wavelength ranges. This system was validated by comparison to traditional methods for the determination of Stern-Volmer constants for alternant and nonalternant polycyclic aromatic hydrocarbons with nitromethane and triethylamine.
Lifetime Cancer Risks of PTEN Mutation Carriers—Response

We thank Daniels and colleagues for their comments on our report ([1][1]). Given that the Cleveland Clinic is the main referral center of patients with germline PTEN mutations in the United States, it is certainly possible that ascertainment bias may exist, an issue we acknowledged in our report.
Development of “stainless” aluminum alloys by surface modification

Abstract In a research project devoted to the elimination of toxic materials in methods of corrosion protection, surface modification processes have been developed to improve the pitting resistance of aluminum alloys without the use of chromates. These processes use chemical treatments in various cerium salt solutions and an electrochemical treatment in a molybdate solution. The details of the surface modification method depend on alloy composition. For Al 6061 and Al 6013 treated by immersion in hot Ce(NO3)3 and CeCl3 followed by anodic polarization in Na2MoO4, pitting did not occur during immersion in 0.5 M NaCl for 60 days. Surface modification of Al 7075-T6 and Al 2024-T3 involves immersion in boiling Ce(NO3)3, anodic polarization in Na2MoO4 and immersion in boiling CeCl3. Very corrosion-resistant surfaces were produced on Al 7075-T6 after applying an electrochemical pretreatment step which removes copper from the outer surface layers. During exposure of Al 7075 in 0.5 M NaCl for 30 days no measurable corrosion was indicated by continuous monitoring with electrochemical impedance spectroscopy and by visual observation. For Al 2024, significant improvements in the resistance to localized corrosion were also obtained with these processes. A further modification of the CeMo process which is very effective for Al 2024 consists of immersion in hot cerium acetate, anodic polarization in Na2MoO4 and immesion in hot Ce(NO3)3. Impedance data collected in 0.5 M NaCl remained capacitive for 30 days, which is indicative of lack of localized corrosion. Surface anlaysis showed increased levels of Ce and Mo at sites where Cu-containing compounds are located. Apparently local cathodes are eliminated during the surface modification process, thereby reducing the driving force for pitting.
Mutations in Sensor 1 and Walker B in the Bovine Papillomavirus E1 Initiator Protein Mimic the Nucleotide-Bound State

Viral replication initiator proteins are multifunctional proteins that utilize ATP binding and hydrolysis by their AAA+ modules for multiple functions in the replication of their viral genomes. These proteins are therefore of particular interest for understanding how AAA+ proteins carry out multiple ATP driven functions. We have performed a comprehensive mutational analysis of the residues involved in ATP binding and hydrolysis in the papillomavirus E1 initiator protein based on the recent structural data. Ten of the eleven residues that were targeted were defective for ATP hydrolysis, and seven of these were also defective for ATP binding. The three mutants that could still bind nucleotide represent the Walker B motif (D478 and D479) and Sensor 1 (N523), three residues that are in close proximity to each other and generally are considered to be involved in ATP hydrolysis. Surprisingly, however, two of these mutants, D478A and N523A, mimicked the nucleotide bound state and were capable of binding DNA in the absence of nucleotide. However, these mutants could not form the E1 double trimer in the absence of nucleotide, demonstrating that there are two qualitatively different consequences of ATP binding by E1, one that can be mimicked by D478A and N523A and one which cannot.
Gastric Emptying and Intestinal Absorption of Carbohydrate and Protein as Influenced by the Nature of the Test Meal

The rate of glucose absorption appears to be governed by the rate at which it is emptied from the stomach (Fenton, '45; Reynell and Spray, '56). The rate of protein absorption has not been extensively investigated, partly because the mix ing of dietary protein in the alimentary tract with endogenous protein of the digestive secretions makes interpretation of the data difficult. The purpose of the present investigation was to observe the disappearance of carbohydrate and pro tein from the alimentary tract as influenced by different car bohydrates and by high and low protein in the diet. There was a need to study separately the contents of the stomach and the small intestine and to extend previous results from this laboratory (Dreisbach and NA¤sset,'54).
Hexamethylene bisacetamide induces programmed cell death (apoptosis) and down-regulates BCL-2 expression in human myeloma cells

Multiple myeloma (MM) is a B cell malignancy characterized by the expansion of monoclonal Ig-secreting plasma cells with low proliferative activity. It is postulated that inhibition of physiologic cell death is an underlying factor in the pathophysiology of MM. The development of chemoresistance is a common feature in patients with MM. In the present studies, hexamethylene bisacetamide (HMBA), a hybrid polar compound that is a potent inducer of terminal differentiation of various transformed cells, is shown to inhibit the growth of several human myeloma cell lines (ARP-1, U266, and RPMI 8226), including doxorubicin-resistant RPMI 8226 variants that overexpress the multidrug-resistance gene, MDR-1, and its product, p-glycoprotein. In addition to growth arrest and suppression of clonogenicity, HMBA induces apoptosis both in freshly isolated human myeloma cells and in cell lines, as determined by morphologic alterations, cell cycle distribution and endonucleosomal DNA fragmentation. Further, HMBA decreases BCL-2 protein expression in myeloma cells within 12–48 hr. Overexpression of BCL-2 protein in ARP-1 cells confers resistance to HMBA-induced apoptosis. Taken together, these data suggest that HMBA is a potent inducer of apoptosis in human myeloma cells, which may act through suppressing the anti-apoptotic function of the bcl-2 gene. HMBA, and related hybrid polar compounds, may prove useful in the management of this presently incurable disease.
The gender earnings gap among pharmacists.

Abstract Background A gender earnings gap exists across professions. Compared with men, women earn consistently lower income levels. The determinants of wages and salaries should be explored to assess whether a gender earnings gap exists in the pharmacy profession. Objectives The objectives of this study were to (1) compare the responses of male and female pharmacists' earnings with human-capital stock, workers' preferences, and opinion variables and (2) assess whether the earnings determination models for male and female pharmacists yielded similar results in estimating the wage-and-salary gap through earnings projections, the influence of each explanatory variable, and gender differences in statistical significance. Methods Data were collected through the use of a 37-question survey mailed to registered pharmacists in South Florida, United States. Earnings functions were formulated and tested separately for male and female pharmacists using unlogged and semilog equation forms. Number of hours worked, human-capital stock, job preferences, and opinion variables were hypothesized to explain wage-and-salary differentials. Results The empirical evidence led to 3 major conclusions: (1) men's and women's earnings sometimes were influenced by different stimuli, and when they responded to the same variables, the effect often was different; (2) although the influence of some explanatory variables on earnings differed in the unlogged and semilog equations, the earnings projections derived from both equation forms for male and female pharmacists were remarkably similar and yielded nearly identical male-female earnings ratios; and (3) controlling for number of hours worked, human-capital stock, job preferences, and opinion variables reduced the initial unadjusted male-female earnings ratios only slightly, which pointed toward the presence of gender bias. Conclusion After controlling for human-capital stock, job-related characteristics, and opinion variables, male pharmacists continued to earn higher income levels than female pharmacists.
Inducible Nitric-oxide Synthase Is Regulated by the Proteasome Degradation Pathway

Inducible nitric-oxide synthase (iNOS) is responsible for nitric oxide (NO) synthesis from l-arginine in response to inflammatory mediators. To determine the degradation pathway of iNOS, human epithelial kidney HEK293 cells with stable expression of human iNOS were incubated in the presence of various degradation pathway inhibitors. Treatment with the proteasomal inhibitors lactacystin, MG132, and N-acetyl-l-leucinyl-l-leucinyl-l-norleucinal resulted in the accumulation of iNOS, indicating that these inhibitors blocked its degradation. Moreover, proteasomal inhibition blocked iNOS degradation in a dose- and time-dependent manner as well as when NO synthesis was inhibited by N(omega)-nitro-l-arginine methyl ester. Furthermore, proteasomal inhibition blocked the degradation of an iNOS splice variant that lacked the capacity to dimerize and of an iNOS mutant that lacks l-arginine binding ability, suggesting that iNOS is targeted by proteasomes, notwithstanding its capacity to produce NO, dimerize, or bind the substrate. In contrast to proteasomal inhibitors, the calpain inhibitor calpastatin and the lysosomal inhibitors trans-epoxysuccinyl-l-leucylamido-4-guanidino butane, leupeptin, pepstatin-A, chloroquine, and NH(4)Cl did not lead to significant accumulation of iNOS. Interestingly, when cytokines were used to induce iNOS in RT4 human epithelial cells, the effect of proteasomal inhibition was dichotomous. Lactacystin added prior to cytokine stimulation prevented iNOS induction by blocking the degradation of the NF-kappaB inhibitor IkappaB-alpha, thus preventing activation of NF-kappaB. In contrast, lactacystin added 48 h after iNOS induction led to the accumulation of iNOS. Similarly, in murine macrophage cell line RAW 264.7, lactacystin blocked iNOS degradation when added 48 h after iNOS induction by lipopolysaccharide. These data identify the proteasome as the primary degradation pathway for iNOS.
Second-Order Divided-Difference Filter Using a Generalized Complex-Step Approximation

This paper presents a framework for the second-order divided-difference filter using a generalized complex-step derivative approximation. For first derivatives the complex-step approach does not suffer substraction cancelation errors as in standard numerical finitedifference approaches. Therefore, since an arbitrarily small step size can be chosen, the complex-step method can achieve near analytical accuracy. However, for second derivatives straight implementation of the complex-step approach does suffer from roundoff errors. Therefore, an arbitrarily small step size cannot be chosen. Previous work expanded upon the standard complex-step approach to provide a wider range of accuracy for both the first and second derivative approximations. The new extensions can allow the use of one step size to provide optimal accuracy for both derivative approximations, which are used in the divided-difference filter in order to improve its accuracy. Simulation results are provided to show the performance of the new complex-step approximations on the divided-difference filter.
BioNEMS: Nanomechanical Systems for Single-Molecule Biophysics

Techniques from nanoscience now enable the creation of ultrasmall electronic devices. Among these, nanoelectromechanical systems (NEMS) in particular offer unprecedented opportunities for sensitive chemical, biological, and physical measurements [1]. For vacuum-based applications NEMS provide extremely high force and mass sensitivity, ultimately below the attonewton and single-Dalton level respectively. In fluidic media, even though the high quality factors attainable in vacuum become precipitously damped due to fluid coupling, extremely small device size and high compliance still yield force sensitivity at the piconewton level - i.e., smaller than that, on average, required to break individual hydrogen bonds that are the fundamental structural elements underlying molecular recognition processes. A profound and unique new feature of nanoscale fluid-based mechanical sensors is that they offer the advantage of unprecedented signal bandwidth (»1 MHz), even at piconewton force levels. Their combined sensitivity and temporal resolution is destined to enable real-time observations of stochastic single-molecular biochemical processes down to the sub-microsecond regime [2].
Integrating Spatial and Discriminant Strength for Feature Selection and Linear Dimensionality Reduction

Interest strength assignment to image points is important for selecting good features. Strength assignments using spatial information aim to detect interest points repeatable across different image/illumination transformations, and have been widely adopted in many interest point detectors. Recently, strength assignment schemes using discriminant information received attention, and studies showed the superiority of discriminant strength. In this paper, we introduce a strength assignment scheme integrating spatial and discriminant information, with the motivation that strong spatial information can be helpful in improving the robustness of the discriminant strength estimation, e.g., in undersampled training scenario. Our integrated strength uses a new discriminant strength assignment, so-called locality oriented Fisher criterion score. The integrated strength leads to new methods for feature selection and weighted linear dimensionality reduction. Experimental results in two case studies (embryo developmental stage classification and face recognition) show the favorable performance of the proposed methods.
Summarizing high-level scene behavior

We present several novel techniques to summarize the high-level behavior in surveillance video. Our proposed methods can employ either optical flow or trajectories as input, and incorporate spatial and temporal information together, which improve upon existing approaches for summarization. To begin, we extract common pathway regions by performing graph-based clustering on similarity matrices describing the relationships between location/orientation states. We then employ the activities along the pathway regions to extract the aggregate behavioral patterns throughout scenes. We show how our summarization methods can be applied to detect anomalies, retrieve video clips of interest, and generate adaptive-speed summary videos. We examine our approaches on multiple complex urban scenes and present experimental results.
In vitro selection of resistance in haemophilus influenzae by 4 quinolones and 5 β-lactams

We tested abilities of ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin, amoxicillin, amoxicillin/clavulanate, cefixime, cefpodoxime, and cefdinir to select resistant mutants in 5 β-lactamase positive and 5 β-lactamase negative Haemophilus influenzae strains by single and multistep methodology. In multistep tests, amoxicillin, amoxicillin/clavulanate and cefpodoxime exposure did not cause >4-fold minimum inhibitory concentration (MIC) increase after 50 days. One mutant selected by cefdinir had one amino acid substitution (Gly490Glu) in PBP3 and became resistant to cefdinir. Cefixime exposure caused 8-fold MIC-increase in 1 strain with TEM but the mutant remained cefixime susceptible and had no alteration in PBP3 or TEM. Among 10 strains tested, ciprofloxacin, moxifloxacin, gatifloxacin, levofloxacin caused >4-fold MIC increase in 6, 6, 5, and 2 strain, respectively. Despite the increases in quinolone MICs, none of the mutants became resistant to quinolones by established criteria. Quinolone selected mutants had quindone resistance-determining region (QRDR) alterations in GyrA, GyrB, ParC, ParE. Four quinolone mutants had no QRDR alterations. Among β-lactams cefdinir and cefixime selected one mutant each with higher MICs however amoxicillin, amoxicillin/clavulanate, and cefpodoxime exposure did not select resistant mutants.
On the effectiveness of incorporating randomness and memory into a multi-start metaheuristic with application to the Set Covering Problem

The construction of good starting solutions for multi-start local search heuristics is an important, yet not well-studied problem. In these heuristics, randomization methods are usually applied to explore new promising areas and memory mechanisms are incorporated with the main purpose of reinforcing good solutions. Under the template of a typical multi-start metaheuristic, Meta-RaPS (Meta-heuristic for Randomized Priority Search), this paper presents several randomization methods and memory mechanisms with a focus on comparing their effectiveness and analyzing their interaction effects. With the Set Covering Problem (SCP) as the application problem, it is found that these randomization methods work well for Meta-RaPS with an improvement phase while the memory mechanisms better the solution quality of the construction phase. The quality and efficiency of Meta-RaPS can be improved through the use of both memory mechanisms and randomization methods. This paper also discovers several efficient algorithms that maintain a good balance between randomness and memory and finds the optimal or best-known solutions for the 65 SCP test instances from the OR-library.
Research on Giftedness and Gifted Education Status of the Field and Considerations for the Future

Gifted education has a rich history and a solid if uneven research base. As policy makers and educators increasingly turn their attention to advanced students and educational excellence, the time is ripe for a dispassionate analysis of the field’s conceptual and empirical strengths and weaknesses. The purpose of this special feature article is to highlight advances in theories and research related to giftedness and gifted education, note the promising areas for additional research, and propose next steps for improving the quality and utility of empirical work in this important area.