cssi/SciSciGPT-SciSciNet huggingface dataset:
Axioms for Geodesics and Their Implications

Publisher Summary This chapter discusses the foundations of metric differential geometry. It explores the extent to which differentiability is necessary. In this context, one of the major advances states that the intrinsic geometry in the large of not necessarily Riemannian spaces. In context to metric differential geometry, the chapter considers several axioms– namely, the space is metric, a bounded infinite set has an accumulation point, and the metric is intrinsic. These axioms are satisfied by a closed convex subset of a Euclidean space. A geodesic is a locally isometric image of the real t -axis. The geodesics on an ordinary cylinder are helices, entire straight lines or circles traversed infinitely. The chapter also presents certain typical results and discusses in detail the theory of parallels.
Pulse Image Processing

The foundations of mammalian visual processing and popular digital image processing algorithms are vastly different. The mammalian system relies on cooperative pulsing activity of neurons to extract segments, textures, edges, and signatures. Popular digital algorithms tend to rely on statistical similarities. The success of the mammalian system justifies the creation of digital simulations and applications. Here a model of the mammalian visual cortex is used to generate several digital applications.
The Inhibitory Effect of trans-10, cis-12 CLA on Lipid Synthesis in Bovine Mammary Epithelial Cells Involves Reduced Proteolytic Activation of the Transcription Factor SREBP-1

The trans-10, cis-12 CLA isomer has been causally related to milk fat depression in dairy cows, although no molecular mechanism has been established. Sterol response element-binding protein (SREBP)-1 is a transcription factor synthesized and retained as a membrane-bound precursor in the endoplasmic reticulum and proteolytically cleaved to release an active fragment that migrates to the nucleus to stimulate lipogenic gene transcription. Certain lipid molecules (i.e., PUFA) were shown to inhibit the proteolytic activation of SREBP-1 in rodent liver models, although there has been no previous demonstration of its presence in bovine tissues or in mammary tissue of any species. We used a bovine mammary cell line (MAC-T) to assess the involvement of SREBP-1 in the regulation of lipid synthesis in bovine mammary cells by trans-10, cis-12 CLA. Treatment with 75 micromol/L trans-10, cis-12 CLA for 48 h resulted in an approximately 50% reduction of (14)C-acetate incorporation into total lipid and corresponding reductions in mRNA abundance for acetyl CoA carboxylase, fatty acid synthase, and stearoyl CoA desaturase, whereas cis-9, trans-11 CLA had no effect on these genes. There was no reduction in SREBP-1 mRNA or precursor protein, but the abundance of the activated nuclear fragment of the protein was significantly reduced by treatment with 75 micromol/L trans-10, cis-12 CLA. These results indicate that trans-10, cis-12 CLA reduces lipid synthesis in the bovine mammary gland through inhibition of the proteolytic activation of SREBP-1 and subsequent reduction in transcriptional activation of lipogenic genes.
CenSSIS: the first year of an engineering research center for subsurface sensing and imaging

Historically, the communities of engineers and scientists who image objects under the ground, under the ocean, inside the body, and inside the cell, have had relatively little contact, despite dealing with similar issues and often using similar mathematical models and algorithms. CenSSIS, the Center for Subsurface Sensing and Imaging Systems, is an NSF Engineering Research Center, developed to bring these seemingly disparate fields together. Conceived at Northeastern University, the Center now has four university partners, four affiliates, and a growing number of corporate and government sponsors. CenSSIS was established to solve real--world problems in these and other fields, to spark revolutionary advances by developing a unified framework for subsurface sensing and imaging systems, and to immerse students and researchers in a multi--disciplinary teaching and learning environment. Already this effort has begun to bear fruit. Here we report on the first full year of activity as an Engineering Research Center.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Optimal Order of One-Point and Multipoint Iteration

The problem is to calculate a simple zero of a nonlinear function ƒ by iteration. There is exhibited a family of iterations of order 2n-1 which use n evaluations of ƒ and no derivative evaluations, as well as a second family of iterations of order 2n-1 based on n — 1 evaluations of ƒ and one of ƒ′. In particular, with four evaluations an iteration of eighth order is constructed. The best previous result for four evaluations was fifth order.It is proved that the optimal order of one general class of multipoint iterations is 2n-1 and that an upper bound on the order of a multipoint iteration based on n evaluations of ƒ (no derivatives) is 2n.It is conjectured that a multipoint iteration without memory based on n evaluations has optimal order 2n-1.
From Eliza to Internet: a brief history of computerized assessment

Three decades of research into the equivalency of traditional and automated assessments have culminated in the growing popularity of Internet-based surveys. This article briefly reviews the history of computerized assessment and compares and contrasts it to the current research on Internet-based surveying.
Simulation of NO and O2 transport facilitated by polymerized hemoglobin solutions in an arteriole that takes into account wall shear stress-induced NO production.

Abstract A mathematical model was developed to study nitric oxide (NO) and oxygen (O2) transport in an arteriole and surrounding tissues exposed to a mixture of red blood cells (RBCs) and hemoglobin (Hb)-based O2 carriers (HBOCs). A unique feature of this model is the inclusion of blood vessel wall shear stress-induced production of endothelial-derived NO, which is very sensitive to the viscosity of the RBC and HBOC mixture traversing the blood vessel lumen. Therefore in this study, a series of polymerized bovine Hb (PolyHb) solutions with high viscosity, varying O2 affinities, NO dioxygenation rate constants and O2 dissociation rate constants that were previously synthesized and characterized by our group was evaluated via mathematical modeling, in order to investigate the effect of these biophysical properties on the transport of NO and O2 in an arteriole and its surrounding tissues subjected to anemia with the commercial HBOC Oxyglobin® and cell-free bovine Hb (bHb) serving as appropriate controls. The computer simulation results indicated that transfusion of high viscosity PolyHb solutions promoted blood vessel wall shear stress dependent generation of the vasodilator NO, especially in the blood vessel wall and should transport enough NO inside the smooth muscle layer to activate vasodilation compared to the commercial HBOC Oxyglobin® and cell-free bHb. However, NO scavenging in the arteriole lumen was unavoidable due to the intrinsic high NO dioxygenation rate constant of the HBOCs being studied. This study also observed that all PolyHbs could potentially improve tissue oxygenation under hypoxic conditions, while low O2 affinity PolyHbs were more effective in oxygenating tissues under normoxic conditions compared with high O2 affinity PolyHbs. In addition, all ultrahigh molecular weight PolyHbs displayed higher O2 transfer rates than the commercial HBOC Oxyglobin® and cell-free bHb. Therefore, these results suggest that ultrahigh molecular weight PolyHb solutions could be used as safe and efficacious O2 carriers for use in transfusion medicine. It also suggests that future generations of PolyHb solutions should possess lower NO dioxygenation reaction rate constants in order to reduce NO scavenging, while maintaining high solution viscosity to take advantage of wall shear stress-induced NO production. Taken together, we suggest that this mathematical model can be used to predict the vasoactivity of HBOCs and help guide the design and optimization of the next generation of HBOCs for use in transfusion medicine.
Drosophila eye development: Notch and Delta amplify a neurogenic pattern conferred on the morphogenetic furrow by scabrous.

Abstract Loss of function mutations of scabrous and conditional alleles of Notch and Delta affect the pattern of morphogenetic furrow development. By studying differentiation of R8 cells, the first photoreceptor neuron subtype to differentiate, we show that all furrow cells pass through an R8-competent stage. Function of Notch and scabrous is necessary if most of these cells are to attain other cell fates. The scabrous gene confers a regular pattern on the morphogenetic furrow, restricting R8 differentiation to alternating groups of cells. Notch and Delta function to restrict the R8 fate to a single cell in each group. Without scabrous gene function, action of Notch and Delta on the entire morphogenetic furrow results in a disorganised pattern of ommatidia arising from a disorganised array of single R8 cells. Aspects of the scabrous mutant phenotype also suggest a secondary role in selecting a single R8 cell from competent clusters. We show that scabrous expression preceeds changes in the apical profiles of morphogenetic furrow cells that identify ommatidial precursor cells, and also preceeds changes in levels of Notch and Delta expression. The pattern of initiation of sca expression depends on sca gene function, indicating that patterning of the morphogenetic furrow depends on the pattern of posterior columns. Our results suggest that in the eye, Notch and Delta amplify and refine a morphogenetic landscape generated by scabrous . Cell determination in other tissues and organisms might also be molded in a two-step process where initial inhomogeneities determined by one protein provide a context for subsequent development.
Experimental analysis of patch dynamics and community heterogeneity in tallgrass prairie

Effects of fire and small-scale soil disturbances on species richness, community heterogeneity, and microsuccession were investigated in a central Oklahoma tallgrass prairie. In the fall of 1985, 0.2 m2 soil disturbances were created on burned and unburned tallgrass prairie. Vegetation on and off disturbances was sampled at monthly intervals over two growing seasons. During the first growing season, the cover of forbs and annuals, and species richness were significantly greater on versus off disturbances, but these differences did not persist through the second year. The variation in species composition among disturbed plots (heterogeneity) was significantly greater compared to undisturbed areas throughout the study. Fire had no consistent effect on richness and heterogeneity of vegetation on soil disturbances but fire reduced heterogeneity on undisturbed vegetation. Rate of succession, based on an increase in cumulative cover of perennial grasses over time, did not differ among treatments during the first growing season. During the second year, rate of succession was significantly greater on burned soil disturbances compared to unburned soil disturbances. These results suggest that while small-scale soil disturbances have primarily short-lived effects on grassland community structure, disturbances do help to maintain spatial and temporal variation in tallgrass prairie communities. Unlike in undisturbed vegetation, however, species richness and heterogeneity on soil disturbances were little effected by fire, but the rate of colonization onto disturbances appeared to be enhanced by fire.
Concepts, Theory, and Techniques DISTRIBUTED COMPUTER SYSTEM DESIGN: A MULTICRITERIA DECISION‐MAKING METHODOLOGY*

The design of distributed computer systems (DCSs) requires compromise among several conflicting objectives. For instance, high system availability conflicts with low cost which in turn conflicts with quick response time. This paper presents an approach, based on multi-criteria decision-making techniques, to arrive at a good design in this multiobjective environment. An interactive procedure is developed to support the decision making of system designers. Starting from an initial solution, the procedure presents a sequence of non-dominated vectors to designers, allowing them to explore systematically alternative possibilities on the path to a final design. The model user has control over trade-offs among different design objectives. This paper focuses on the details of the mathematical model used to provide decision support. Accordingly, a formulation of DCS design as a multicriteria decision problem is developed. The exchange search heuristic used to generate nondominated solutions also is presented. We argue that multicriteria models provide a more realistic formulation of the DCS design problem than the single-criterion models used widely in the literature. While obtaining a clear definition of design objectives (single or multiple) is an important activity, by explicitly acknowledging the trade-offs among multiple objectives in the design process, our methodology is more likely to produce a better overall design than methods addressing a single criterion in isolation.
Restructuring, Workers' Pension Rights, and the Law

This paper extends analysis of the intersection between economic and geographical restructuring, unions, and corporate pension liabilities. The focus here is on Gavalik v Continental Can Co., a suit brought in federal district court alleging that the company had violated Section 510 of the Employee Retirement Income Security Act by laying off workers and relocating work at the company's Pittsburgh plant. After considering the role of unions in the growth and expansion of private pensions in the United States, and the current case in the context of litigation over the power of Section 510, the legal arguments made by the plaintiffs and defendants in federal courts are examined. Emphasized are issues relating to the motivations of the corporation, as well as the courts' determination of what are legal and illegal actions.
Age-Dependent Effects of Methamphetamine on VMAT-2

Abuse of methamphetamine (METH) among adolescents and young adults is concerning since studies have demonstrated that multiple administrations of high-dose METH induce persistent dopaminergic deficits. METH has also been shown to reduce dopamine (DA) uptake by the vesicular monoamine transporter-2 (VMAT-2) and to reduce the amount of VMAT-2 protein in a purified vesicular fraction. VMAT-2 plays a critical role in the sequestration of DA in dopaminergic nerve terminals. This function is important since DA can oxidize rapidly to form highly reactive species. It is likely that disruption of this normal intracellular processing of DA contributes to oxidative sequences ultimately leading to persistent deficits. Interestingly, METH appears to be less toxic in adolescent rats compared to young adult rats. VMAT-2 is proposed to play an important role in the age-dependent difference. Since the effect of METH on the function and quantity of VMAT-2 has primarily been studied in young adult rats and since developmental changes in the dopaminergic system are reported to occur between adolescence and adulthood, it is important to determine if there is an age-dependent difference in response of VMAT-2 to METH.
Sexual Minority Women Who Use Drugs: Prejudice, Poverty, and Access to Care

Access to care is a critical issue for ameliorating the health and social impact of marginalization. Research indicates that sexual minority women experience low utilization of medical care overall, combined with high levels of substance abuse and lack of access to culturally appropriate services. This study uses qualitative data to examine factors that affect access to services for sexual minority women who use(d) heroin or crack cocaine. Semi-structured interviews were done with 34 sexual minority women drug users, of diverse sexual identities, recruited from community-based agencies. Interviews explored factors shaping service utilization, including basic life history, self-assessed needs, positive and negative experiences with service providers, and barriers to care. Analysis explored prejudice and discrimination at institutional and interactional levels, the role of social policy, the interactional dynamics surrounding gender presentation, and how these institutional and social processes shape individual experience. The women who participated in this study described multiple layers of marginalization that limited access to—and discouraged use of—a range of vital services, but their stories simultaneously demonstrated the power of personal networks and low-threshold agencies to share resources, provide bridges to services, and build supportive communities.
Involutive Functionals, Infinite Dimensional Tori, and Neighboring Tori☆

In the class of smooth periodic functions, we consider Hamiltonian equationsut=K(u), constants of the motionFm(u) that are in involution, and prove an infinite-dimensional version of Liouville's Theorem. We explain in what sense the generic level set of the functionalsFm(u) is an infinite-dimensional torus, why the solution of the Hamiltonian equation is almost periodic in time, and describe how neighboring generic infinite-dimensional tori are related. The proof of the Theorem is independent of the method of inverse spectral theory and the viewpoint of algebraic curves.
The three-dimensional structure of α-actinin obtained by cryoelectron microscopy suggests a model for Ca2+-dependent actin binding

The three-dimensional structure of α-actinin from rabbit skeletal muscle was determined by cryoelectron microscopy in combination with homology modeling of the separate domain structures based on results previously determined by X-ray crystallography and nuclear magnetic resonance spectroscopy. α-Actinin was induced to form two-dimensional arrays on a positively charged lipid monolayer and micrographs were collected from unstained, frozen hydrated specimens at tilt angles from 0 ° to 60 °. Interpretation of the 15 A-resolution three-dimensional structure was done by manually docking homologous models of the three key domains, actin-binding, three-helix motif and the C-terminal calmodulin-like domains. The initial model was refined quantitatively to improve its fit to the experimental reconstruction. The molecular model of α-actinin provides the first view of the overall structure of a complete actin cross-linking protein. The structure is characterized by close proximity of the C-terminal, calmodulin-like domain to the linker between the two calponin-homology domains that comprise the actin-binding domain. This location suggests a hypothesis to explain the involvement of the C-terminal domain in Ca2+-dependent actin binding of non-muscle isoforms.
Safety Performance of G4 (1S) W-Beam Guardrails versus Cable Median Barriers on Florida's Freeways

Different roadside safety hardware including guardrails and cable barriers have been installed on freeways to prevent run-off-the-road and median crossover crashes. This article compares the safety performance of G4 (1S) strong-post W-beam guardrails and cable barriers installed in the medians on freeways in Florida. The comparison is based on the percentages of barrier and median crossovers by vehicle type and crash severity. A crash is categorized as barrier crossover crash if the errant vehicle crosses the barrier during the crash. If after crossing the barrier the errant vehicle clears the median and traverses into the opposite travel lanes, it becomes a median crossover crash. To obtain a more precise measurement of barrier performance, this study considers only crashes involving vehicles hitting a barrier. A total of 678.9 miles of freeways with G4 (1S) W-beam guardrails and 101.0 miles of freeways with cable barriers were identified. Police reports of 8,536 crashes from years 2006 to 2010 at these locations were reviewed. Z-test and odds ratio were used to compare the safety performance of cable median barriers and guardrails. Overall, guardrails performed slightly better than cable barriers in terms of barrier and median crossover crashes. However, cable median barriers were found to result in fewer severe injury crashes.
Pancreatic Dornase Aerosol in Pulmonary, Endotracheal and Endobronchial Disease

(Vanidase), trypsin and of detergents such as alevaire has been popularized. Trypsin has been shown to be effective by many investigators18 but not universally.9 Serious complications have been reported,’. � �‘ � � and almost all authors advise use of antihistamines9 and/or epinephnine or ephednine inhalations with trypsin.4’ 5, 8 The effects of these drugs themselves have not been considered in these reports. Vanidase has been used with less success.”�4 Detergents, particularly alevaire, are in common use and have been reported to be effective.’5 Continuous therapy by tent or nasal catheters, on repeated treatments each day for several days are necessary to obtain results.’5 Pancreatic desoxyribose-nuclease (dornase) prepared by the method of McCarty’6 was first used in patients with thick purulent sputum, such as those with bronchiectasis, with excellent results.’7 Satisfactory results with a purified pancreatic dornase have been reported, with a review of pharmacological effects of the drug.’8 No irritating effects were noted. Pancreatic dornase and trypsin have been used together with good effect but many serious reactions.19 We set out to evaluate the usefulness of this purified pancreatic dornase in all pulmonary conditions presented as unresolved by standard procedures. The local effects and general reactions to dornase were also studied by clinical and laboratory means, including bronchoscopy and pathological examination of resected specimens. The effect of pancreatic dornase on the discovery of malignant disease by cellular cytology from bronchial washings was also studied. Materials Pancreatic desoxyribose-nuclease (dornase) was furnished in sterile vials of 100,000 units.* Sterile diluent was supplied in vials of 10 cc.
Multiple Forms of Bacterial NADP-Specific Isocitrate Dehydrogenase

Electrophoretically distinct forms of nicotinamide adenine dinucleotide phosphate-specific isocritrate dehydrogenase have been observed in extracts of Escherichia coli grown under different culture conditions. In glucose-grown cells, two distinct bands of isocitrate dehydrogenase activity were observed on polyacrylamide gels and have been completely resolved by employing ion-exchange chromatography. These multiple forms of the enzyme have been studied and their possible metabolic role is discussed.
Automated AI Planning and Code Pattern Based Code Synthesis

The past decade has seen great progress in the development of embedded real-time systems, which are playing increasingly important roles in various application domains. However, the growing complexity of these systems has revealed the urgent need to develop advanced techniques to reduce the time-to-market as well as the overall system development cost. One method for achieving both of these goals is automated code synthesis combined with component based software development (CBSD). This enables the synthesizer to focus on generating the glue code needed to assemble an application from existing components. The main challenge is how to enable the synthesizer to recognize and generate complex conditional or loop statements. In this paper, a pattern-based code synthesis approach is enhanced to enable it to synthesize new loop statements. Specifically, we use an extended version of Graphplan to help the synthesizer to recognize and generate new loop statements. The paper proposes a planning domain model for code patterns and an automated code synthesis system, which integrates the enhanced AI planner with the Code Pattern Integration System (CPIS) to fully automate the code synthesis process.
Perioperative Outcomes in Patients Undergoing Conventional Laparoscopic Versus Laparoendoscopic Single-site Pyeloplasty

OBJECTIVES To compare the outcomes of laparoendoscopic single-site (LESS) surgery with conventional laparoscopic pyeloplasty (CLP) before LESS can be widely accepted. LESS surgery is a novel technique for performing laparoscopic pyeloplasty through a single incision. METHODS Fourteen patients undergoing less pyeloplasty were matched 2:1 with regard to age and side of surgery to a previous cohort of 28 patients who underwent CLP. All patients underwent surgery for symptomatic ureteropelvic junction obstruction and/or delayed urinary excretion based on functional imaging. Intracorporeal suturing was aided through a 5-mm instrument placed in the eventual drain site. RESULTS No difference was observed between the LESS and CLP cohorts in regard to preoperative characteristics. Postoperatively, no difference was noted between LESS and CLP cases in regard to length of stay (77 vs 74 hours; P = .69), morphine equivalents required (34 vs 38; P = .93), minor postoperative complications (14.3% vs 14.3%; P = 1.0), or major postoperative complications (21.4% vs 10%; P = .18). Median operative times (207 vs 237.5 minutes; P <.001) and median estimated blood loss (30 vs 72.5 mL; P = .002) were lower in patients undergoing LESS. Detailed follow-up imaging revealed a success rate of 96% for CLP at 14.6 months (86% follow-up) and 100% for LESS at 6.8 months (71% follow-up). CONCLUSIONS Although LESS pyeloplasty is feasible, all measured perioperative outcomes are similar to CLP. Further studies are needed to better define the appropriate role of LESS surgery in urology.
The 29 kDa light chain that regulates axonemal dynein activity binds to cytoplasmic dyneins.

In earlier studies, Hamasaki et al. (Proc. Natl. Acad. Sci. USA. 88:7918-7922, 1991) and Barkalow et al. (J. Cell Biol. 126:727-735, 1994) found that cAMP- and Ca2+-sensitive phosphorylation of a 29 kDa dynein light chain (p29) extracted from 22S axonemal dynein of Paramecium, regulates the velocity of in vitro microtubule translocation and ciliate swimming speed. In this study we report evidence of recombination of p29 to cytoplasmic dyneins from both rat liver and Paramecium, as well as to a 22S dynein precursor molecule, based on immunoprecipitation and force filtration data. Immunoprecipitation also provides additional evidence for the binding of p29 to 22S axonemal dynein. The results suggest that p29 might regulate cytoplasmic dynein, as well as axonemal dynein function in Paramecium, and that a homologue of p29 may exist in rat liver and other mammalian cells. Cell Motil. Cytoskeleton 39:1–8, 1998. © 1998 Wiley-Liss, Inc.
Capital punishment, the moratorium movement, and empirical questions: Looking beyond innocence, race, and bad lawyering in death penalty cases.

This article briefly explores the underpinnings of the contemporary capital punishment moratorium movement and examines executive and legislative responses to calls for a halt to executions, including suggestions for studying the death penalty process. Although most investigations focus on select issues like innocence, ineffective counsel, and race bias, this article suggests that a wide-ranging constellation of issues should be investigated in any legitimate attempt to evaluate the administration of the death penalty. The article canvasses this broader sweep of issues, discusses related research evidence, and then considers the policy implications of conducting such a thorough empirical assessment of the administration of capital punishment in this country.
Lycopene Stability During Food Processing

Accumulating epidemiological evidence continues to show that lycopene, found in tomatoes, grapefruits and watermelons, is associated with a reduced risk of developing certain chronic diseases and cancers. With respect to lycopene in tomato products, the effect of thermal processing on its stability has not yet been rigorously addressed. This paper assesses the effect of several different heat treatments on lycopene's isomeric distribution in a variety of tomato products, as well as in organic solvent mixtures containing all-trans lycopene. Experimental results indicate that in contrast to beta-carotene, lycopene remained relatively resistant to heat-induced geometrical conversion during typical food processing of tomatoes and related products. The presence of fat, the change in percentage of solids, and the severity of heat treatment were not contributing factors in the formation of lycopene isomers in tomato products, except at extreme conditions not regularly employed in the food industry or during food preparation. However, lycopene in organic solvent isomerized readily as a function of time even in the absence of light and the presence of antioxidants. These findings suggest that while lycopene is stable in the tomato matrix, sample handling techniques should be carefully evaluated to minimize the formation of lycopene cis isomers in organic solutions.
Porphyrin-cyclophanes : inclusion complexation and X-ray crystal structure of a zinc octamethyldiphenylporphyrin

Abstract The synthesis, characterization, and complexation properties of two novel porphyrincyclophanes are reported. In the first system, one face of an octamethyldiphenylporphyrin is capped by one diphenylmethane unit. In the second system, both faces of a tetraphenylporphyrin are strapped by diphenylmethane units. The X-ray crystal structure has been determined for the singly-capped zinc octamethyldiphenylporphyrin.
Modeling Kinetic Data from In Vitro Drug Metabolism Enzyme Experiments

Modeling of in vitro enzyme kinetic data derived from drug metabolism experiments can greatly facilitate the drug development process because estimation of kinetic parameters can facilitate decision making regarding whether to continue development of a compound. From this information, predictions can be made regarding the "metabolic stability" of a compound and even the in vivo intrinsic clearance of the drug. Many drugs exhibit typical Michaelis-Menten-type kinetics in vitro that result in a hyperbolic kinetic profile from which Km and Vm can be readily estimated. However, it is increasingly being recognized that many drug compounds exhibit "atypical" enzyme kinetics in vitro, requiring use of more complex kinetic models for data fitting and parameter estimation. These atypical kinetic profiles may include sigmoidal kinetics (autoactivation), biphasic kinetics, substrate inhibition kinetics, and heterotropic cooperativity (activation). This article briefly summarizes the types of equations necessary to adequately model both typical and atypical kinetic profiles in order to facilitate correct estimation of the relevant kinetic parameters.
A synthesis of diketopiperazines using polyphosphoric acid.

Conversion of an alpba -amino acid to its corresponding 2,5-diketopiperazine was accomplished by heating the amino acid with a suitable dehydrating agent such as polyphosphoric acid. This procedure, after the excess polyphosphoric acid was decomposed and neutralized, when applied to glycine, alanine, leucine, isoleucine, and phenylalanine, gave good yields of the corresponding diketopiperazines. The temperature of the reaction is the most critical factor in obtaining satisfactory yields. The optimum reaction conditions for each of the five amino acids are reported.
DSM interconnect effects on system-on-chip design flows

Interconnect scaling to 0.13 μm and below technology processes has a tremendous impact on design flows. The author looks at the issues created by DSM scaling and how tools can deal with them.
Trends in airline passenger trip delays (2007 – 2009)

Delays in arrival of airline passengers should be the on-time performance metric of the airline passenger transportation system (not flight delays). A passenger trip can experience arrival delays, relative to the ticketed arrival time, as a result of a delayed flight, as well as a diverted flight, cancelled flight, denied boarding, and/or missed connection. This paper describes the results of analysis of annual passenger trip delays for U.S. domestic airline flights from 2007 to 2009. These results are based on estimated itineraries and load factors, and actual airline (flight) on-time performance data available from government websites.
Temperature controls a latitudinal gradient in the proportion of watershed nitrogen exported to coastal ecosystems

Increased export of biologically available nitrogen (N) to the coastal zone is strongly linked to eutrophication, which is a major problem in coastal marine ecosystems (NRC (2000) Clean Coastal Waters: Understanding and Reducing the Effects of Nutrient Pollution. National Academy Press, Washington, DC; Bricker et al. (1999) National Estuarine Eutrophication Assessment. Effects of nutrient enrichment in the nation’s estuaries. NOAA-NOS Special Projects Office, Silver Spring, MD). However, not all of the nitrogen input to a watershed is exported to the coast (Howarth et al. (1996) Biogeochemistry 35:75–139; Jordan and Weller (1996) Bioscience 46:655–664). Global estimates of nitrogen export to coasts have been taken to be 25% of watershed input, based largely on northeastern U.S. observations (Galloway et al. (2004) Biogeochemistry 70:153–226; Boyer et al. (2006) Global Biogeochem Cycle 20:Art. No. GB1S91). We applied the N budgeting methodology developed for the International SCOPE Nitrogen project (Howarth et al. (1996) Biogeochemistry 35:75–139; Boyer et al. (2002) Biogeochemistry 57:137–169) to 12 watersheds in the southeastern U.S., and compared them with estimates of N export for 16 watersheds in the northeastern U.S. (Boyer et al. (2002) Biogeochemistry 57:137–169). In southeastern watersheds, average N export was only 9% of input, suggesting the need for downward revision of global estimates. The difference between northern and southern watersheds is not a function of the absolute value of N inputs, which spanned a comparable range and were positively related to export in both cases. Rather, the proportion of N exported was significantly related to average watershed temperature (% N export = 58.41 e−0.11 * temperature; R 2 = 0.76), with lower proportionate nitrogen export in warmer watersheds. In addition, we identified a threshold in proportionate N export at 38°N latitude that corresponds to a reported breakpoint in the rate of denitrification at 10–12°C. We hypothesize that temperature, by regulating denitrification, results in increased proportionate N export at higher latitudes. Regardless of the mechanism, these observations suggest that temperature increases associated with future climate change may well reduce the amount of nitrogen that reaches estuaries, which will have implications for coastal eutrophication.
The Evaluation and Management of Insomnia

Insomnia is a highly prevalent malady and adversely affects many dimensions of daily human function. Although its pathophysiology is poorly understood, it seems to arise in the context of heightened arousal in neurophysiologic and psychological systems. Because it often coexists with a wide variety of medical and psychiatric conditions, the first task in the management of this condition is to identify comorbid disorders through a comprehensive evaluation. Once identified, specific treatments can be tailored to the underlying conditions. Effective cognitive/behavioral and pharmacologic management techniques are available for primary insomnia.
Thermal and catalytic properties of alumina-pillared Montmorillonite prepared in the presence of polyvinyl alcohol

Abstract Na-montmorillonite was pillared with alumina in an aqueous solution of polyvinyl alcohol (PVA). The surface area was always more than 100 m2 g−1 larger than that of montmorillonite pillared without PVA after calcining at elevated temperatures. On calcining at 1073 K, the surface area still exceeded 200 m2 g−1 for the former montmorillonite, while it was negligibly small for the latter. It was concluded that pillaring in the presence of PVA resulted in an enhancement of the heat stability of alumina-pillared montmorillonite in the sense that high-temperature calcination led to a less pronounced decrease in the surface area. Nitrogen adsorption isotherms suggested that the pore size was larger for pillaring in the presence of PVA than in its absence. Between these two alumina-pillared montmorillonites, catalytic activity for the alkylation of toluene with methanol varied with the calcination temperature in a very different way. An approximate correlation was observed between the activity and the surface area on the montmorillonite pillared in the absence of PVA. On the montmorillonite pillared in the presence of PVA, on the other hand, the activity was very low after calcination at 773 K, despite the larger surface area. The elevation of the calcination temperature resulted in an increase in the activity: after calcination at 1073 K, the activity was at almost the same high level as that for pillaring in the absence of PVA. The cause for the observed activity variation was discussed in terms of residual carbon originating from PVA.
Reactions of [W(NH=NR)(CO)2(PPh3)2+][PF6−] with azide and amines that occur without displacement of the NH=NR ligand

Abstract The d 6 tungsten phenyldiazene complex [ trans , trans -W (NH=NPh) (CO) 2 (NO) (PPh 3 ) 2 + ][PF 6 − ] ( 1a ) reacted with ammonia, methylamine or hydrazine at −78°C giving [ trans -W (NH=NPh) (CO) (NO) (NH 2 R) (PPh 3 ) 2 + ][PF 6 − ] ( 2a , R = H; 2b , R = CH 3 ; 2c , R = NH 2 ) as purple salts in good yield, along with one equivalent of carbon monoxide. Sodium azide reacted with la or the p -tolyldiazene derivative [ trans , trans -W(NH=NTol)(CO) 2 (NO)(PPh 3 ) 2 + ][PF 6 − ] ( 1b ) in the presence of a proton source giving CO and [ trans , trans -W(NHNHR)(N 3 ) 2 (NO) (PPh 3 ) 2 ] ( 3a , R = Ph, 3b , R = Tol), neutral bis (azido) complexes containing arylhydrazido ligands. These reactions involving nitrogen nucleophiles are in striking contrast with the known activity of 1a,b with Br − that gives [ trans -W(Br)(CO) 2 (NO)(PPh 3 ) 2 ] and free NH = NPh.
How to Compare Different Loss Functions and Their Risks

Many learning problems are described by a risk functional which in turn is defined by a loss function, and a straightforward and widely known approach to learn such problems is to minimize a (modified) empirical version of this risk functional. However, in many cases this approach suffers from substantial problems such as computational requirements in classification or robustness concerns in regression. In order to resolve these issues many successful learning algorithms try to minimize a (modified) empirical risk of a surrogate loss function, instead. Of course, such a surrogate loss must be "reasonably related" to the original loss function since otherwise this approach cannot work well. For classification good surrogate loss functions have been recently identified, and the relationship between the excess classification risk and the excess risk of these surrogate loss functions has been exactly described. However, beyond the classification problem little is known on good surrogate loss functions up to now. In this work we establish a general theory that provides powerful tools for comparing excess risks of different loss functions. We then apply this theory to several learning problems including (cost-sensitive) classification, regression, density estimation, and density level detection.
SCREENING FOR CORTICOSTEROIDS IN TOPICAL PHARMACEUTICALS BY HPLC WITH A SCANNING ULTRAVIOLET DETECTOR

A screening procedure was developed for the detection of 49 corticosteroids in topical pharmaceutical products. These products were analyzed by reversed-phase HPLC using two gradient systems: a linear gradient of 18–82% acetonitrile over 12 min and a linear gradient of 38–88% methanol over 12 min. Although all corticosteroids were not resolved during a single 12-min gradient analysis, a peak retention time from a sample analysis was usually sufficient to limit an unknown to 1–3 probable corticosteroids. Steroids unresolved with the first gradient system were resolved with the second one, with the exception of three steroid pairs. Assignments based on retention times were supported by spectra provided by a rapid scanning ultraviolet detector. Two extraction procedures were developed to isolate corticosteroids from both water-soluble and lipid-soluble sample components. When applied to a variety of topical formulations, the two extraction methods eliminated most of the sample excipients, recovered corticost...
Postorder B-tree construction

A method is presented for building B-trees from a sorted list of records without node splitting. There are several advantages to such an approach. The number of records stored per node can be independently specified for each level of the tree, what Knuth calls a generalized B-tree. Once a node is filled it need not be referenced again. If the tree is being stored on a DASD the number of accesses, O(N/d) for N keys and an order-d tree, will be less than required for methods that use node splitting.
Dental abnormalities in the osteopetrotic rat mutation microphthalmia blanc.

Abstract Dental manifestations of the mild, transient osteopetrosis in the rat mutation microphthalmia blanc ( mib ) were examined. Eruption of all teeth was delayed in mib rats compared to normal littermates. The delays ranged from 5 days for incisors to 3 and 2 days for the first and second molars. Normal rats had straight incisors in the sagittal plane that exhibited signs of wear, but in mib littermates the incisors were maloccluded, distorted, and snowed no signs of wear. Radiographic and histological examination of the dentition of 1- and 4-week-old rats revealed that the apical end of incisors in mib rats failed to extend posteriorly to the third molar region as in normal siblings, but ended at the first molar. Histological examination of longitudinal sections of mandibles through the incisors of neonatal normal and mib rats showed that in 1-day-old mutants the incisor was closely surrounded by alveolar bone to which it was ankylosed. The incisor body in mib rats was also malformed, with an indented apical end. This ankyosis was temporary, being resolved by 3 days. These findings show that neonatal reductions in bone resorption cause incisor defects and delay the eruption of all teeth in mib rats. The malocclusion and distortion of incisors of mib rats are likely caused by temporary ankylosis of incisor matrices to alveolar bone. Taken together, these findings illustrate the concept that bone resorption is an essential and rate-limiting element of tooth eruption.
RNS representations with redundant residues

Residue number system (RNS) representations that contain redundant moduli have been extensively studied with regard to their error checking properties. A second form of redundancy in RNS, that of redundant residues, has been applied in certain application contexts to gain speed and cost benefits. Such applications are developed in an ad hoc manner and there does not exist a theoretical framework for the latter variety of redundant RNS. We develop a theory of RNS representations with redundant residues and show how representation parameters affect the speed and complexity of various arithmetic operations. The theory parallels that of redundant signed-digit representations in that at issue are choice of 'residue sets' (akin to digit sets), encoding of residue sets, conversions between residue sets with different degrees of redundancy, including none, and algorithms for arithmetic on redundant-residue operands.
Microencapsulated Bovine Chromaffin Cells In Vitro: Effect of Density and Coseeding with a NGF-Releasing Cell Line

Immobilization of discrete cell clusters within a partially crosslinked matrix prevents reaggregation of primary tissues and may provide a means for long-term maintenance of encapsulated cells. Dissociated bovine adrenal chromaffin (BAC) cells were suspended throughout crosslinked polyanionic microspheres previously shown to be selectively permeable. Microcapsules approximately 500 µm in diameter were seeded with: 1) three different densities of BAC cells; and 2) BAC cells suspended in Matrigel® or coseeded with a genetically modified nerve growth factor (NGF)- releasing fibroblast cell line. Each group was analyzed in vitro at 1, 4 and 8 weeks for spontaneous and potassium-evoked release of catecholamines, and maintained in vitro for up to 12 weeks for morphological observations. Over time, release of norepinephrine (NE) and epinephrine (EPI) diminished, while dopamine (DA) remained constant from the monoseeded capsules. In the coseeded group, an increase in potassium-evoked release of DA was observed from 1 to 4 weeks, and remained at that level up to 8 weeks. Encapsulated chromaffin cells retained a rounded morphology typical of undifferentiated cells. Intact chromaffin cells with well preserved and abundant secretory granules were observed ultrastructurally after 4 weeks in vitro. Small neurites from the chromaffin cells in the coseeded group were observed at 4 weeks with light microscopy, and up to 12 weeks with electron microscopy. Under static incubation conditions, 1 mM D-amphetamine resulted in a significant increase in the output of NE and DA from the coseeded capsules 8 weeks postimplantation, as compared to microcapsules loaded with chromaffin cells alone. Encapsulation within an immobilization matrix allows manipulation of the internal environment, thereby providing the ability to pre-treat cells with various factors in a non-invasive manner, which may enhance long-term cellular viability.
Optimal two-layer approximation for continuous density stratification

Two-layer fluids of finite depth under gravity are the simplest configuration capable of supporting internal wave motion. The extent to which such systems can be used to provide quantitative information on smoothly stratified fluids, in configurations relevant for geophysical applications, is analysed and a model of practical interest derived. The model is based on long-wave asymptotic expansions and on first-principle criteria for an optimal choice of effective two-layer parameters for the incompressible, smoothly stratified Euler equations. The accuracy of the model is extensively tested, via fully resolved numerical computations, on the class of travelling wave solutions supported by smooth stratification systems. It is found that, despite the severe restrictions posed by the discrete two-layer density assumption, solitary wave solutions corresponding to experimentally realizable parametric values can be accurately predicted, in both wave and fluid parcel markers, such as phase speed and density fields, respectively. Thanks to this analysis, explicit closed-form solutions are available for all relevant physical quantities. The agreement between the simple, optimized two-layer model and the parent smooth-stratification Euler system persists up to extreme cases, such as that of internal fronts, and even up to thicknesses of the pycnocline comparable to that of the effective layers.