cssi/SciSciGPT-SciSciNet huggingface dataset:
Complex Numbers in Algebra

The next three chapters revisit the topics of algebra, curves, and functions, observing how they are simplified by the introduction of complex numbers. That’s right: the so-called “complex” numbers actually make things simpler. In the present chapter we see where complex numbers came from (not from quadratic equations, as you might expect, but from cubic equations) and observe how they simplify the study of polynomial equations. Equations become simpler because they always have solutions in the complex numbers, and it follows that they have the “right” number of solutions. One of the reasons for the simplifying power of complex numbers is their two-dimensional nature. The extra dimension gives more room for solutions of equations to exist. For example, the equation x n = 1, which has only one or two solutions in the real numbers, has n different solutions in the complex numbers, equally spaced around the unit circle. More generally, complex numbers give a way to divide any angle into n equal parts. This comes about because multiplication of complex numbers involves addition of angles, and is related to the famous de Moivre formula in trigonometry. The equation x n = 1 is not the only one with the “right” number of solutions in the complex numbers. In fact, any equation of degree n has n complex solutions, when solutions are properly counted. This is the fundamental theorem of algebra, and it follows from intuitively simple properties of the plane and continuous functions.
Making War, Not Love: Gender and Sexuality in Russian Humor

Reviewed Medium: book Authors: Emil A. Draitser Year: 1999 Pages: viii + 308 Publisher: St. Martin's Press Prices: $45.00
Prognostic factors for squamous cell cancer of the parotid gland: An analysis of 2104 patients

Background Parotid gland squamous cell cancer (SCC) occurs as metastasis from cutaneous SCC or primary malignancy. There is limited data on incidence, prognosis, and treatment outcomes. Methods The Surveillance, Epidemiology, and End Results (SEER) database (1988–2009) identified 2104 adult patients with parotid SCC. Results SCC is the second most common parotid malignancy, and its incidence is increasing (annual percentage change 1.7%; ptrend = .004). Age ≥85 years, tumor size ≥4 cm, extraparenchymal extension, cervical metastases, and distant metastases were independently associated with disease-specific mortality. Compared to no surgery, surgery was associated with improved 5-year disease-specific survival (DSS; 44.4% vs 71.0%; p < .001), whereas radiation alone was similar to no treatment (47.0% vs 41.6%; p = .28). Conclusion Surgery and adjuvant radiation therapy (RT) are associated with improved survival compared to radiation alone and no treatment. Patients ≥85 years of age account for nearly 20% of all patients and have a poor prognosis independent of treatment. © 2014 Wiley Periodicals, Inc. Head Neck 37: 1–7, 2015
Satellite architecture [for autonomous on-orbit servicing]

This paper describes an effort to develop an avionics architecture that enables replacement of deficient satellite hardware on-orbit as well as upgrade/adapt on-orbit systems. It is anticipated that routine, safe, and reliable spacecraft servicing will have significant payoff for many future types of science and military missions. Satellites that are placed on-orbit and are functionally lost due to simple failures beg for the development of an on-orbit replacement capability. To date, this has been performed by an astronaut. Human intervention in space, however, carries risk and cost associated with it that would not be necessary if an autonomous satellite repair capability was developed. The associated capability to perform pre-planned upgrades and adaptations to on-orbit space assets also has the potential for architecting high performance future spacecraft. The first step in developing a serviceable satellite is to evolve the tightly integrated satellite architectures of today toward an architecture that supports functional and/or physical replacement of anomalous or failed hardware. Draper Laboratory has performed a trade study to develop a single-point architecture that provides a growth path from the functionally efficient satellite designs of today to a functionally reliable modular architecture that will support the autonomous on-orbit upgrade and functional enhancement of tomorrow's satellites. This paper presents an overview of an architecture that can enable autonomous satellite servicing.
Incorporating Photography as a Therapeutic Tool in Counseling

Over a period of 150 years, photographic images have contributed to how we see and think about the world, ourselves, and others. Individuals who are particularly resistant to therapy and those who communicate better with the use of visual aids may not benefit from standard counseling practices alone. Although verbal communication is vital in most forms of therapy, several alternative expressive therapies are available. As a form of complementary and alternative therapy, photography has shown to be beneficial for individuals who express themselves more adequately with visual aids. As an expression of reality, photography assists the rehabilitation counseling process and has been implemented in various therapeutic settings. This article also describes several international organizations that encourage and support the use of phototherapy for rehabilition of people in need.
A hybridization method for autoradiographic visualization of small unique sequence fragments resolved on polyacrylamide gels.

Abstract A useful method is described for sequence-specific visualization of small nucleic acid fragments on polyacrylamide gels. Excess highly radioactive probe is annealed in solution to smaller fragments. The resulting hybrids are trimmed (under appropriate conditions) with S1 nuclease to yield duplex fragments whose sizes are determined by the strand contributed by the smaller unlabeled fragment, but which also contain a labeled strand from the radioactive probe. These fragments can then be resolved on polyacrylamide gels and visualized by drying the gel and subjecting it to autoradiography. This method is shown to visualize fragments as small as 40 base pairs.
Characterization of Adsorbed Ionic Surfactants on a Mica Substrate

An AFM study is presented to investigate the morphology of adsorbed cationic surfactants on mica substrates. At low surfactant concentrations and low pH values, discrete aggregates of adsorbed surfactants are found on the surface. As the surfactant concentration is increased, these aggregates become more organized into elongated cylindrical shapes. The continuity of the network of patches increases until a concentration just below the cmc. At this concentration, the patches become continuous “wormlike” admicelles on the surface. Contact angle measurements corroborate the change in the surface properties from hydrophobic at low surfactant concentrations to hydrophilic at concentrations slightly below the cmc. Force versus distance curves also clearly indicate a change in surface morphology. It is clear from our observations that the formation of dense continuous monolayers or bilayers does not occur as postulated earlier. Indeed our observations suggest the formation of discrete surfactant aggregates on th...
The sequences of the N protein gene and intergenic region of the S RNA of pichinde arenavirus.

Abstract Two overlapping DNA clones representing more than half of the Pichinde arenavirus S RNA segment were cloned into pBR322 and their nucleotide sequences were determined. The analyses predict that the viral nucleocapsid protein (N) is encoded in a reading frame in the viral complementary RNA sequence starting at viral S RNA nucleotide residue 84 from the 3′ end and terminating with an opal codon at residues 1767–1769. The position of the termination codon has been confirmed by primer directed dideoxynucleotide sequencing. The N protein has a calculated size of 62,911 Da and a net positive charge of +9. Viral complementary 15 S mRNA that directs the synthesis of N protein and hybridizes to the predicted N gene DNA has been identified in infected cell extracts. A second nonoverlapping reading frame in the viral complementary sequence originates at nucleotide position 1827 and remains open for at least 71 amino acids (i.e., the extent of the second clone). A long stretch of hydrophobic amino acids is near the amino terminus of this predicted gene product. Between the two reading frames is a 60-nucleotide-long noncoding intergenic region. This nucleotide sequence can be arranged in hairpin configuration involving 14 G-C and 4 A-U base pairs. The possible function of this intergenic region in the regulation of transcription and/or translation is discussed.
Early protected motion after extensor tendon repair.

Abstract Thirty hands with 50 extensor tendon lacerations, excluding mallet finger injuries, were examined. They were treated with surgical repair followed by immediate motion which included a dynamic splinting and tendon mobilization program. The average follow-up period was 7 months (range, 8 weeks to 2 years). Forty-five of the 50 tendons regained full range of motion (average total active motion, 262°) within an average time of 9 weeks; the remaining 5 tendons had extension lags of ≤10°. All patients regained at least 93% of their predicted normal strength within 9 to 12 weeks and returned to their previous level of activity in an average of 10 weeks. These results, which include complex lacerations, are an improvement from previously published data. This is probably due to the addition of a tendon mobilization program to dynamic splinting following extensor tendon repair. (J Hand Surg 1999;24A:1061–1070. Copyright © 1999 by the American Society for Surgery of the Hand.)
Comparison of confined mandrill (Mandrillus sphinx) behavior in traditional and “ecologically representative” exhibits

Behavior in a confined group of mandrills (Mandrillus sphinx) was compared before and after their move from a traditional, all indoor exhibit to an indoor/outdoor facility. The outdoor exhibit was designed to represent as well as is possible important features of the mandrills' forest habitat. We predicted that activity budgets in the outdoor exhibit would more closely resemble those of wild African Cercopithecines, specifically that time spent in forage/feed, locomotion, and social behavior would increase and time spent stationary would decrease. Time spent in forage/feed, locomotion, and stationary did change, as expected. However, there was a small significant decrease in some social behaviors. Differences in proximate environmental contingencies may explain the behavioral changes observed: feeding/foraging opportunities throughout the time on exhibit; increased social refuges; modest increase in facility size; and significantly increased environmental complexity and novelty. Our results are discussed within the context of data obtained from mandrills and baboons observed along a theoretical continuum between confined and free-ranging environments. This analysis supports what others have suggested: that primate well-being is not so much a function of confinement as of the presence of relevant incentives to engage in species-appropriate behavior. Zoo Biol 18:163–176, 1999. © 1999 Wiley-Liss, Inc.
Design and fabrication of disposable percutaneous chemical sensors

Abstract  Sencils (sen sory cilia) are chemical sensors that are minimally invasive, disposable and easily readable to make freque nt measurements of various analytes in vivo over a period of 1-3 months. A percutaneous optical fiber permits precise, reliable photonic measurement of chemical reactions in a nano-engineered poly mer matrix attached to the internal end of the fiber. The first Sencils sense interstitial glucose based on mea surement of fluorescence resonance energy transfer (FRET) between fluorophors bound to dextran and Concanavalin-A in a polyethylene glycol (PEG) matrix. In vitro experiments demonstrate a rapid and precise relationship be tween the ratio of the two fluorescent emissions and concentration of gluc ose in saline over the physiological range of 0-500mg/dl. Chronic implantation in pigs has demonstrated biocompatibility. The Sencil platform can be adapted to detect other analytes in interstitial fluids. Keywords  Optical fiber, chemical sensor, fluorescence resonance energy transfer, affinity-binding assay, glucose, Quantum dots 1 The Potential of Chemical Sensing in vivo Although biosensors have been used in clinical application for decades, most of the commercialized products are intended for in vitro assays of samples expelled or extracted from body (urine, blood, tissue etc.). These sensors have significant disadvantages for monitoring fluctuating physiological processes because it is impractical to obtain these samples more than once or twice a day. In order to manage certain diseases and conditions, it is important to make frequent measurements of specific analytes over an extended pe riod of time. These include diabet es, cancer chemotherapy treatment, and hormonal monitoring for fertility and complications of pregnancy. Continuous in vivo monitoring could reduce the complications of diabetes from hyperglycemia and hypoglycemia (insulin overdosage). Frequent monitoring could increase the safety and ef fectiveness of chemotherapy by measuring interstitial drug levels and detecting apoptosis of tumor cells in situ without sampling through biopsy. The technology can also benefit basic research in molecular biology, drug discovery and veterinary medicine. For example, some metabolites and secondary messengers in signaling transduction pathways can only be traced directly through in vivo detection (Harper et al.). Tracking such activity without requiring biopsies or sacrificing experimental animals wo uld expedite such research (Wiley et al.). Sencils can be implanted precisely in solid tumors and other tissues to provide highly localized information. 2 Challenges of chemical sensing in vivo Over the past twenty years, there have been many research projects to develop minimally invasive chemical sensors but relatively few products have been approved for clinical use. The requirements discussed below tend to compete with each other, making it difficult to develop and validate strategies that achieve useful tradeoffs among them.
System testing: implications of requirements specifications

Abstract On many software development projects, software system testing takes considerably longer than predicted. Even worse, the resultant product often fails to meet customer expectations. It is well understood and documented that the requirements specification process as currently practised is grossly inadequate. Perhaps this inadequate requirements process is a cause of the apparent inadequate software system testing process. The paper explores the qualities of a well written requirements specification. It also provides insight into how the lack of each of these qualities can have profound effects on the potential success or failure of software system testing. More attention to quality during the requirements specification process can help alleviate these problems.
The Continuing Significance of Racism Discrimination Against Black Students in White Colleges

In the last few years we have seen a growing concern among academic administrators and educational researchers about Black student enrollment and attrition rates. A number of survey studies (Astin, 1977, 1982) have found that college enrollment and graduation rates for Black Americans have declined in many programs. In a recent major review of the literature, George Keller (19881989), professor at the University of Pennsylvania Graduate School of Education and recipient of the Casey Award in education planning, examined nine books, reports, and special journal issues devoted to assessing the problems of minority access and achievement in higher education. Keller's analysis (pp. 50-54), representative of much social science and policy analysis of minority problems, notes the extensive discussion of minority student attrition and suggests 10 reasons that are documented in the literature he reviewed:
All-trans retinoic acid regulates adhesion mechanism and transmigration of the acute promyelocytic leukaemia cell line NB-4 under physiologic flow.

The success of all-trans retinoic acid (ATRA) in the therapy of acute promyelocytic leukaemia (APL) has received increased attention. Unfortunately, life-threatening multiorgan failure commonly occurs, i.e. retinoic acid syndrome, and is thought to be the result of organ infiltration by leukaemic cells. We hypothesized that ATRA-induced differentiation of APL cells leads to adhesion receptor alterations responsible for leucocyte extravasation from the blood into tissue. Changes in adhesive properties of the APL cell line NB-4 in response to ATRA were investigated using a parallel plate flow chamber under conditions that recapitulate physiologic flow conditions. Untreated NB-4 cells initially tether and roll on activated human umbilical vein endothelial cell monolayers using a combination of E-selectin, P-selectin and alpha4 integrin. After ATRA treatment, > 80% of initial NB-4 cell attachment to endothelial cells was E-selectin dependent. Stable arrest (firm adherence) of NB-4 cells on activated endothelium was also altered by ATRA treatment. Untreated NB-4 cells used alpha4 integrin to arrest on endothelium, but beta2 integrin dependent arrest was induced by ATRA. With the acquisition of beta2 integrin function, ATRA-treated cells acquired the ability to transmigrate through activated endothelium. Thus, ATRA dramatically altered the adhesion phenotype on NB-4 cells: ATRA induced rolling largely attributable to E-selectin, abrogated alpha4 integrin dependent rolling, and promoted acquisition of beta2 integrin dependent firm adherence and transmigration. These findings represent novel cellular and differentiation effects of ATRA, and, to our knowledge, are the first demonstration that a therapeutic agent differentially regulates alpha4 and beta2 integrin on the same leucocyte.
Representation of the computer-aided design process by a network of decision tables☆

Abstract Large-scale implementation of computer-aided design of structural systems, as opposed to the analysis or mathematical optimization of such systems, had been largely unsuccessful to date, owing largely to the difficulty of representing the myriad decisions and processing steps involved. It is shown that decision tables are an ideal tool for representing the detailed decisions and processing steps. The interaction between the data items and the transformations including decision tables is concisely represented by networks of ingredience and dependence. Finally, the iterative, open-ended nature of the design process is accommodated by assigning to each data item a status indicator, which specifies whether the item is valid or void. It is shown that only two basic recursive routines are needed to link the data together, either to evaluate a given item by evaluating all of its ingredients or to make all dependents of a modified data item void. Examples illustrating the application of the representation are included, using the 1969 AISC Specifications as a basis.
Tobramycin‐neomycin cross‐sensitivity

Fifty normal control volunteers were patch tested to 20% neomycin as well as tobramycin 1%, 10%, 20% and 30% in white petrolatum. Tobramycin is a new aminoglycoside antibiotic for prescription ophthalmologic use in the United States. There were no reactions on any of the control volunteers. Twenty known and proven neomycin-allergic patients were then tested to tobramycin 10% and 20% in white petrolatum, as well as to neomycin 20% aqueous and 20% in white petrolatum. All 20 reacted with a 2+ or greater response to the neomycin patch tests. Twelve out of the 20 or 60% of the neomycin-allergic patients reacted to the 10% tobramycin in white petrolatum. Thirteen out of 20 or 65% reacted to 20% tobramycin in white petrolatum. From these data, tobramycin (ophthalmic) should not be used to treat known neomycin-allergic patients without first patch testing the patient with 20% tobramycin in white petrolatum. It appears probable that 65% of neomycin-allergic patients would react with a dermatitic response to such therapy.
Cutaneous melanoma-associated paraneoplastic retinopathy: histopathologic observations.

Abstract PURPOSE: To describe the retinal histopathology of paraneoplastic retinopathy associated with cutaneous melanoma. METHODS: A 59-year-old man had visual loss attributable to paraneoplastic retinopathy and died of metastatic cutaneous melanoma. His eyes were studied by conventional histopathologic techniques. RESULTS: Histopathologic examination of both eyes disclosed a marked reduction in the density of bipolar neurons in the inner nuclear layer; photoreceptor cell neurons in the outer nuclear layer were normal. Ganglion cells were present, although many showed evidence of transsynaptic atrophy. CONCLUSION: The histopathologic changes observed are consistent with clinical, immunologic, and electrophysiologic data that implicate the bipolar cell as the major site of the paraneoplastic process in cutaneous melanoma-associated retinopathy.
Personality differences between successfully and unsuccessfully treated drug abusers

Personality differences of 71 residents in a therapeutic community drug abuse programme were examined with the Minnesota Multiphasic Personality Inventory (MMPI). Successfully treated males scored significantly ( p < .05) higher on scales of Hypochondriasis (Hs), Hysteria (Hy), and Masculinity-Femininity (Mf). Successfully treated females obtained a significantly ( p < .05) higher score on the Social Introversion (si) Scale. Unsuccessfully treated females scored significantly ( p < .05) higher than the successfully treated females on the Masculinity-Femininity (Mf) Scales. Of the two-point code types, all of the 49-94 code types were unsuccessful; the largest number of successfully treated drug abusers for any one code type was in the 48-84 code type.
Comparison of experiment with calculations using curvature-corrected zero and two equation turbulence models for a two-dimensional U-duct

In this paper experimental measurements are compared with Navier-Stokes calculations using seven different turbulence models for the internal flow in a two-dimensional U-duct. The configuration is representative of many internal flows of engineering interst that experience strong curvature. In an effort to improve agreement, this paper tests several versions of the two-equation k-epsilon turbulence model including the standard version, an extended version with a production range time scale, and a version that includes curvature time scales. Each is tested in its high and low Reynolds number formulations. Calculations using these new models and the original mixing length model are compared here with measurements of mean and turbulence velocities, static pressure and skin friction in the U-duct at two Reynolds numbers. The comparisons show that only the low Reynolds number version of the extended k-epsilon model does a reasonable job of predicting the important features of this flow at both Reynolds numbers tested.
Analyzing Multiple Multivariate Time Series Data Using Multilevel Dynamic Factor Models.

Multivariate time series data offer researchers opportunities to study dynamics of various systems in social and behavioral sciences. Dynamic factor model (DFM), as an idiographic approach for studying intraindividual variability and dynamics, has typically been applied to time series data obtained from a single unit. When multivariate time series data are collected from multiple units, how to synchronize dynamical information becomes a silent issue. To address this issue, the current study presented a multilevel dynamic factor model (MDFM) that analyzes multiple multivariate time series in multilevel SEM frameworks. MDFM not only disentangles within- and between-person variability but also models dynamics of the intraindividual processes. To illustrate the uses of MDFMs, we applied lag0, lag1, and lag2 MDFMs to empirical data on affect collected from 205 dating couples who had at least 50 consecutive days of observations. We also considered a model extension where the dynamical coefficients were allowed ...
Challenges in Meeting the Mental Health Needs of Urban Asian American Adolescents: Service Providers’ Perspectives

Although Asian American youth are often viewed as the model minority group who are doing well, research with youths, parents, and school personnel have documented significant unmet mental health needs among this population. However, little is known about the perspectives of service providers who work with Asian American youth in afterschool and mental health care settings with respect to what they perceive as challenges meeting the psychosocial needs of the population. The current exploratory study used Consensual Qualitative Research to analyze in-depth interviews with mental health providers, educators, and advocates working with Asian American youths in a multiethnic large urban environment. Results found that service providers were attuned to the multiple needs of the community but also spoke of challenges in meeting basic and psychological needs due to difficult family dynamics, structural stressors (e.g., economic and legal), and societal stigma and discrimination. We draw implications for providing more integrated services across different levels of urban Asian American adolescents’ ecological system to better meet the psychosocial challenges facing this population.
Copper and signal transduction: platelets as a model to determine the role of copper in stimulus-response coupling.

Platelets from copper-deficient rats have been used as a model to investigate the role of copper in receptor-mediated cellular responses. Copper deficiency doubles the rate of dense granule secretion and increases myosin association with the platelet cytoskeleton following thrombin stimulation. Mechanisms underlying the effects of copper deficiency on thrombin- induced signals that elicit dense granule secretion involve suppression of protein kinase C activity and impairment of Ca2+ release from intracellular stores. Copper deficiency also reduces the cellular GTP content of platelets. This may limit receptor effector coupling through GTP-dependent regulatory proteins leading to protein kinase C activation and the release of Ca2+ from intracellular stores. The reduction in GTP content during copper deficiency results from its utilization to maintain cellular ATP levels in response to severely inhibited cytochrome c oxidase activity in platelet mitochondria. Thus, the role of copper in maintaining normal signal transduction may be indirectly related to its biological function in mitochondria.
Adaptation of an information quality framework to measure customers’ behavioral intentions to use lodging Web sites

Abstract The information quality of commercial Web sites is becoming a focal point in the current consumer behavior literature. A consumer's perceived quality of information for products and services on the Web is believed to be the most salient factor for predicting his/her decision behavior. Combining the concepts of information quality and consumer decision behavior, this study tested a framework to evaluate the information quality of simulated lodging Web sites. Two hundred and forty conference attendees evaluated the information quality of one of eight hypothetically designed lodging Web sites. Results indicated that the adapted information quality model could be a useful framework for evaluating information quality on lodging Web sites. Of the four constructs of information quality, perceived usefulness and attitudes were found to be significant indicators to predict the customers’ purchase behavior using the lodging Web sites.
Role of interface layer in stress-induced leakage current in high-k/metal-gate dielectric stacks

The impact of the Silica-based interface layer (IL) thickness on stress induced leakage current (SILC) on highk/metal-gate transistors is studied at various constant voltage stresses (CVS) and at various temperatures. It is shown that high-k/metal-gate transistors reliability can be greatly improved with interface layer optimization.
Acceptability of Mature Turkeys and Fryer Chickens Cooked On the Bone and Off the Bone

Abstract An increasing amount of further processed poultry is being fabricated into roll and loaf type products but little information is available as to the possible organoleptic changes due to the removal of meat from the bone. This study was made to determine whether mature turkeys and fryer chickens cooked on the bone differed organoleptically from the corresponding meat made into rolls or loaves. The products were evaluated by a trained taste panel using the triangle test to determine differences. Shear values were also obtained. There were significant differences between turkey dark meat roasted on the bone and the corresponding deboned parts. Dark meat of chicken roasted on the bone and deboned were also significantly different. Shear values were lower for the meat cooked on the bone. Significant differences were also noted between turkey and fryer meat cooked on the bone and the corresponding parts made into loaves. Generally, turkey meat cooked on the bone was preferred but when phosphate (Kena) was added to the loaves, the reverse was true. Fryer meat in the form of loaves was preferred in most cases.
PARSING SURROUNDING SPACE INTO REGIONS

Surrounding space is not inherently organized, but we tend to treat it as though it consisted of regions (e.g., front, back, right, and left). The current studies show that these conceptual regions have characteristics that reflect our typical interactions with space. Three experiments examined the relative sizes and resolutions of front, back, left, and right around oneself. Front, argued to be the most important horizontal region, was found to be (a) largest, (b) recalled with the greatest precision, and (c) described with the greatest degree of detail. Our findings suggest that some of the characteristics of the category model proposed by Huttenlocher, Hedges, and Duncan (1991) regarding memory for pictured circular displays may be generalized to space around oneself. More broadly, our results support and extend thespatial framework analysis of representation of surrounding space (Franklin & Tversky, 1990).
Human Unsupervised and Supervised Learning as a Quantitative Distinction

SUSTAIN (Supervised and Unsupervised STratified Adaptive Incremental Network) is a network model of human category learning. SUSTAIN initially assumes a simple category structure. If simple solutions prove inadequate and SUSTAIN is confronted with a surprising event (e.g. it is told that a bat is a mammal instead of a bird), SUSTAIN recruits an additional cluster to represent the surprising event. Newly recruited clusters are available to explain future events and can themselves evolve into prototypes/attractors/rules. SUSTAIN has expanded the scope of findings that models of human category learning can address. This paper extends SUSTAIN to account for both supervised and unsupervised learning data through a common mechanism. The modified model, uSUSTAIN (unified SUSTAIN), is successfully applied to human learning data that compares unsupervised and supervised learning performances.
HALOENOL LACTONES AS INACTIVATORS AND SUBSTRATES OF ALDEHYDE DEHYDROGENASE

Human aldehyde dehydrogenase (EC 1.2.1.3) isozymes E1 and E2 were irreversibly inactivated by stoichiometric concentrations of the haloenol lactones 3-isopropyl-6(E)-bromomethylene tetrahydro-pyran-2-one and 3-phenyl-6(E)-bromomethylene tetrahydro-pyran-2-one. No inactivation occurred with the corresponding nonhalogenated enol lactones. Both the dehydrogenase and esterase activities were abolished. Activity was not regained on dialysis or treatment with 2-mercaptoethanol. The inactivation was subject to substrate protection: NAD afforded protection which increased in the presence of the aldehyde-substrate competitive inhibitor chloral. Saturation kinetics gave positivey-axis intercepts, allowing the determination of binding constants. Inactivation stiochiometry determined with14C-labeled 3-(1-naphthyl)-6(E)-iodomethylene tetrahydropyran-2-one was found to correspond to the active-site number. The nonhalogenated lactone, 3-(1-naphthyl)-6(E)-methylene tetrahydropyran-1-one was shown to be a substrate for aldehyde dehydrogenase via its esterase function. Inactivation and enzymatic hydrolysis occurred within a similar time frame. Opening of the lactone ring to form enzyme-acyl intermediate with active site cysteine appears to be a necessary prerequisite to inactivation, since halogen in the lactone ring is nonreactive. Thus, the inactivation of aldehyde dehydrogenase by haloenol lactones is mechanism-based. Inactivation by haloenol lactones occurs in a manner analogous to that of chymotrypsin with which aldehyde dehydrogenase shares esterase activity and binding of haloenol lactones at the active site.
Blue Gene/L compute chip: synthesis, timing, and physical design

As one of the most highly integrated system-on-a-chip application-specific integrated circuits (ASICs) to date, the Blue Gene®/L compute chip presented unique challenges that required extensions of the standard ASIC synthesis, timing, and physical design methodologies. We describe the design flow from floorplanning through synthesis and timing closure to physical design, with emphasis on the novel features of this ASIC. Among these are a process to easily inject datapath placements for speed-critical circuits or to relieve wire congestion, and a timing closure methodology that resulted in timing closure for both nominal and worst-case timing specifications. The physical design methodology featured removal of the pre-physical-design buffering to improve routability and visualization of buses, and it featured strategic seeding of buffers to close wiring and timing and end up at 90% utilization of total chip area. Robustness was enhanced by using additional input/output (I/O) and internal decoupling capacitors and by increasing I/O-to-C4 wire widths.
Marine Vadose Beachrock Cementation by Cryptocrystalline Magnesian Calcite--Maui, Hawaii

ABSTRACT Active precipitation of high-magnesian cryptocrystalline calcite cement (15.5 mole % MgCO3) in the intertidal zone on the north shore of Maui, Hawaii, results in formation of an extensive beachrock exposure at Hookipa Park. Framework grains in the beachrock are coarse algal, molluscan, and intraclast-bearing sands. Meniscus fabric is dominant in the cement, indicating that most lithification occurs in the vadose zone. The cryptocrystalline cement is generally brownish gold in color, but very thin, clear isopachous fringes of microcrystalline calcite surround darker cryptocrystalline cement, especially in upper horizons of the beachrock. Peloidal texture is scarce in the cement but is present in a few samples. Silt and fine-sand-sized skeletal fragments have been trapped in he evolving cement, resulting in cement-supported fabric. Hollow rims of microcrystalline calcite occupy some pore spaces. These hollow rims may have precipitated at the air-water interface of bubbles that formed in pores, and they may therefore be additional evidence of cementation in the vadose zone. Interstitial water samples from wells that penetrate portions of the beachrock and unconsolidated beach sands reveal temporal chemical variations that suggest the importance of CO2 degassing in the formation of beachrock cement. When chemical and tidal cycles fluctuate with the same period, PCO2 values in pore water of the intertidal zone generally bear a direct relationship to tidal stand. Increasing values of PCO2 most often occur during semi-daily rising tides and decreasing values of PCO2 occur during falling tides. Saturation ratios with respect to calcite vary in direct proportion to PCO2. Saturation levels generally increase during rising tides and decrease during falling tides. T ese data suggest that CO2 degassing during falling tides results in precipitation of calcite cement from pore water of the beach.
Nesidioblastosis is Not a Histopathologic Diagnosis. 380

Nesidioblastosis is a condition characterized clinically by intractable hyperinsulinemic hypoglycemia. Since serum insulin levels are rarely extremely elevated, diagnostic confirmation has historically relied upon characteristic histopathologic changes in the pancreatic tissue removed as a therapeutic modality of this condition. Although the finding of abundant nests of endocrine tissue budding off of ductal elements is considered to be confirmatory, there have been reports in the adult and pathology literature that such findings may be present in normal individuals. We present here the case of an infant which demonstrates that nesidioblastosis is not a histopathologic diagnosis.
Absolute CH concentration measurements in low-pressure methane flames: comparisons with model results

Abstract Absolute CH concentration profiles were measured for rich and lean premixed, low-pressure, laminar-flow methane flames, using laser-induced fluorescence calibrated with a Rayleigh scattering technique. Agreement between measured concentrations and GRI-Mech 3.0/Premix model predictions varies with flame stoichiometry: measured and predicted maximum CH concentrations and position agree well for a near-stoichiometric flame, but predicted values are approximately 20% too large for rich flames and too small for the lean flame. The model, constrained by a measured temperature profile, predicts the [CH] peak to be too far from the burner for rich flames and too close for the lean flame. Measured OH concentrations give good agreement with model results for all flame stoichiometries.
Numerical simulation of air pollution in urban areas: Model development

Abstract A three-dimensional, grid-based numerical air pollution model for the estimation of air pollutant concentrations in an urban area is developed. Based on the continuity equation, the modeling system incorporates the combined influences of advective transport, turbulent diffusion, chemical transformation, source emissions and surface removal of air contaminants. Recent developments in plume rise and plume penetration processes, objective wind field analysis procedures and numerical solution techniques incorporated into the model are described.
(±)-2-Oxocyclohexanepropionic acid: dual conformational selection and hydrogen bonding in a δ-keto acid, and a two-phase technique for crystallizing acids by contact with aqueous solutions of their salts

The asymmetric unit of the title compound, C(9)H(14)O(3), consists of two molecules having conformations that differ by 121.7 (4) degrees in their rotation about the equatorial substituent bond, so that the side chain extends away from the ring in different directions in the two species. The hydrogen-bonding mode is acid-to-acid dimerization. However, despite the centrosymmetric space group (P-1), the dimers are asymmetric, formed by pairing molecules of identical chirality but differing conformational type [O...O = 2.681 (2) and 2.654 (2) A, and O-H...O = 175 (3) and 176 (3) degrees ]. Two intermolecular C-H...O=C close contacts exist, involving the ketone group of one of the molecules. A two-phase technique is described for slow reforming of crystals of a water-insoluble acid by contact with an aqueous solution of its water-soluble salt.
skn-1-Dependent and -Independent Regulation of aip-1 Expression following Metabolic Stress in Caenorhabditis elegans

Maintenance of a stable, properly folded, and catalytically active proteome is a major challenge to organisms in the face of multiple internal and external stresses which damage proteins and lead to protein misfolding. Here we show that internal metabolic stress produced by reactive intermediates resulting from tyrosine degradation triggers the expression of the aip-1 gene, which is critical in responses to the environmental toxin arsenic and the clearance of unstable polyglutamine and Aβ proteins. aip-1 acts via binding to the proteosome and enhancing proteosomal function. We find that full induction of aip-1 depends on the oxidative-stress-responsive skn-1 transcription factor but significant induction still occurs without skn-1. Importantly, activation of skn-1 with wdr-23(RNAi), which dramatically induces the expression of other skn-1 target genes, produces a minimal increase in aip-1 expression. This suggests that the previously demonstrated specificity in aip-1/AIRAP induction could reflect the actions of multiple synergistic activators, such as the heat shock factor homolog hsf-1, which we also find is required for full induction. These may be triggered by proteosome dysfunction, as we find that this event links the multiple inducers of aip-1. Together, our results show that cell stress triggers aip-1 expression by both skn-1-dependent and -independent pathways.
Sculpting nanostructures with light

We show that it is possible to pattern nanostructures with long-wavelength photons, effectively breaking the far-field diffraction barrier. We also present approaches to single-molecule spatial resolution with light in 3 dimensions.
Numerical study of finned heat pipe-assisted thermal energy storage system with high temperature phase change material

In the present study, the thermal characteristics of a finned heat pipe-assisted latent heat thermal energy storage system are investigated numerically. A transient two-dimensional finite volume based model employing enthalpy-porosity technique is implemented to analyze the performance of a thermal energy storage unit with square container and high melting temperature phase change material. The effects of heat pipe spacing, fin length and numbers and the influence of natural convection on the thermal response of the thermal energy storage unit have been studied. The obtained results reveal that the natural convection has considerable effect on the melting process of the phase change material. Increasing the number of heat pipes (decreasing the heat pipe spacing) leads to the increase of melting rate and the decrease of base wall temperature. Also, the increase of fin length results in the decrease of temperature difference within the phase change material in the container, providing more uniform temperature distribution. It was also shown that number of the fins does not have a significant effect on the performance of the system.
Cost optimal preventive maintenance and replacement scheduling

In this paper, we present a method for predicting a cost-optimal preventive maintenance policy for a repairable system with an increasing Rate of Occurrence Of Failure (ROCOF). We segment the maintenance planning horizon into n discrete and equally-sized periods. For each period, we predict which of three possible actions, (maintain the system, replace the system, or do nothing to the system) should be taken, such that the total net present worth of all future costs is minimized. Our model expands upon previous work by utilizing the concept that maintenance reduces the “effective age” of the system and hence the system ROCOF. We develop the model and evaluate three solution procedures, namely, a random search, a genetic algorithm, and a branch-and-bound approach. The entire approach is illustrated through the use of a numerical example.
Early and late outcome of percutaneous transluminal coronary angioplasty for subacute and chronic total coronary occlusion

Percutaneous transluminal coronary angioplasty (PTCA) for nonacute total coronary occlusion was performed in 46 patients, with a 63% primary success rate (29 of 46 procedures). There were no acute myocardial infarctions and no deaths in the study group. There was no difference in success rate according to vessel dilated, prior myocardial infarction, or lesion morphology. The success rate with occlusions 2 weeks' duration (p =NS). There was clinical recurrence in 14 of 29 (48%). Factors predictive of recurrence included a greater residual post-PTCA stenosis of 47 ± 6% in recurrences vs 31 ± 3% in nonrecurrences (p < 0.025), while estimated duration of initial occlusion was 1.1 ± 0.4 months for recurrences vs 3.1 ± 1 months for nonrecurrences (p = 0.07). PTCA for total occlusion has a lower success rate and higher recurrence rate than PTCA for nontotal stenoses. Recurrence appears to be related to a higher degree of post-PTCA residual narrowing and to a shorter duration of initial occlusion.
Microscopical model for polarization stability in optically anisotropic VCSELs

A comparative study between microscopic and macroscopic models describing polarization switching in optically anisotropic VCSELs is presented. The microscopic model includes: (1) steady-state, many-body multi-band microscopic theory for the optical response of semiconductor quantum wells; (2) the polarization properties of vectorial eigenmodes of VCSEL structures including mode-dependent losses and frequencies; (3) realistic model for optical anisotropies resulting from intentional or unintentional strain in an active quantum-well layer. A macroscopic model is derived from this microscopic model. It provides a rigorous generalization of the phenomenological approaches to the description of polarization properties of VCSELs used commonly in the literature. The optical anisotropy of the VCSEL structure is assumed to result from anisotropic strain of the active quantum well materials. The valence band anisotropy and heavy-hole light-hole mixing effects determine the system characteristics like anisotropic gain and refractive index. The results of microscopic and macroscopic models agree very well for input/output characteristics of anisotropic VCSELs. Also, the stability properties of polarization eigenmodes are qualitatively the same, although the ranges of stability are quantitatively different for both approaches. Incorporation of many-body effects into the analysis usually diminishes the agreement between microscopic and macroscopic theories.
Inhibition of RNase II by DNA.

Summary Extracts of Escherichia coli contain an inhibitor of RNase II activity that is likely to be oligonucleotides of DNA. Purified RNase II is also inhibited by partially digested DNA.
Dental Health Personnel Planning: a Review of the Literature

Dental personnel planning is important in formulating policy in dental education, dental public health programs, and dental care delivery systems. The purpose of this literature review is to illustrate the use of dentist-to-population ratios, need-based models, and demand-based models in the determination of appropriate supply of dental personnel. A historical perspective is provided that demonstrates how political manipulation and subjectivity have characterized the use of these models by organized dentistry, the federal government, and others. The lack of pertinent data and the inability to predict economic, social, political, and epidemiologic trends weaken the applicability of each model in determining future personnel levels. Considering the long-term consequences of the use of each model in personnel planning, caution is urged in using any of the presently available models.
Effect of flux on the wetting characteristics of SnAg, SnCu, SnAgBi, and SnAgCu lead-free solders on copper substrates

The effect of flux on the wetting characteristics of four lead-free solders, Sn-3.5Ag, Sn-0.7Cu, Sn-3.5Ag-4.8Bi, and Sn-3.8Ag-0.7Cu (wt.%), on copper substrates have been studied at 240, 260, and 280°C. The fluxes investigated were rosin (R), mildly activated rosin (RMA), and activated rosin (RA). The wetting tests were conducted using the sessile-drop method. Results showed that fluxes significantly affect the wetting properties of the solders. Contact angles ranging from 10° to 30° for RMA, 20° to 30° for RA, and 35° to 60° for R were obtained. The effect of temperature on contact angle depended on the type of flux used. The contact angle decreased with increasing temperature; however, in some cases the contact angle was independent of temperature. The Sn-3.5Ag-4.8Bi exhibited the lowest contact angles indicating improved wettability with addition of bismuth. The microstructure of the solder/copper interface was analyzed by scanning electron microscopy.