cssi/SciSciGPT-SciSciNet huggingface dataset:
Fistulotomy or fistulectomy and primary sphincteroplasty for anal fistula (FIPS): a systematic review

There is still no clear consensus about surgical treatment of anal fistulas. Fistulotomy or fistulectomy and primary sphincter reconstruction is still regarded with skepticism. The aim of this systematic review was to evaluate the evidence in the literature supporting the use of this technique in the treatment of complex anal fistulas. MEDLINE, EMBASE and Cochrane Library databases were searched for the period between 1985 and 2015. The studies selected were peer-reviewed articles, with no limitations concerning the study cohort size, length of the follow-up or language. Technical notes, commentaries, letters and meeting abstracts were excluded. The major endpoints were the technique adopted, clinical efficacy, changes at anorectal manometry and assessment of quality of life after the procedure. Fourteen reports (666 patients) satisfied the inclusion criteria. The quality of the studies was low. Some differences about the surgical technique emerged; however, after a weighted average duration of follow-up of 28.9 months, the overall success rate was 93.2 %, with a low morbidity rate. The overall postoperative worsening continence rate was 12.4 % (mainly post-defecation soiling). In almost all cases, the anorectal manometry parameters remained unchanged. The quality of life, when evaluated, improved significantly. Fistulotomy or fistulectomy and primary sphincteroplasty could be a therapeutic option for complex anal fistula. Success rates were very high and the risk of postoperative fecal incontinence was lower than after simple fistulotomy. Well-designed trials are needed to support the inclusion of this technique in a treatment algorithm for the management of complex anal fistulas.
On the Structural Stability and Solvent Denaturation of Proteins II. DENATURATION BY THE UREAS

Abstract The denaturation of sperm whale myoglobin, horse heart cytochrome c, and bovine α-chymotrypsinogen by various water-miscible amides has been investigated by spectral, difference spectral, and optical rotatory dispersion methods. As in the case of denaturants of the type of alcohols, glycols, and ureas, the effectiveness of the amides was found to increase with increasing hydrocarbon content and alkyl substitution of their functional amino groups. Branching of the hydrocarbon portion of the substituent groups of the latter compounds decreased their effectiveness as protein denaturants. Analysis of the denaturation data based on the theories of Peller and Flory, with appropriate binding constants and Setschenow parameters calculated from the solubilities of N-acetyl-l-tryptophan ethyl ester, has shown that hydrophobic interactions play an increasingly important role with increasing hydrocarbon content in the mode of action of the amides as denaturants.
Posttraumatic stress disorder: the burden to the individual and to society.

Background Little is known about the total population prevalence and societal costs of posttraumatic stress disorder (PTSD); this report reviews relevant literature on these topics. Method A literature search of computerized databases for published reports on trauma and PTSD was conducted. This literature was reviewed to find data on general population exposure to trauma, conditional risk of PTSD among those exposed to trauma both in focused samples of trauma victims and in general population samples, and the adverse consequences of PTSD. Results PTSD was found to be a commonly occurring disorder that often has a duration of many years and is frequently associated with exposure to multiple traumas. The impairment associated with PTSD in U.S. samples, where the majority of research on these consequences has been carried out, is comparable to, or greater than, that of other seriously impairing mental disorders. Risk of suicide attempts is particularly high among people with PTSD. Available evidence suggests that the prevalence of PTSD and the adverse emotional and psychological consequences of PTSD are much greater in the many countries around the world that are in the midst of armed conflicts involving political, racial, or ethnic violence. Conclusion PTSD is a highly prevalent and impairing condition. Only a minority of people with PTSD obtain treatment. Early and aggressive outreach to treat people with PTSD could help reduce the enormous societal costs of this disorder.
Scientific Management and Pragmatism in PA Theory: Taylor and Dewey as Strange Bedfellows

Scientific management in public administration is usually associated with the Philadelphian, machinist and industrial engineer Frederick Winslow Taylor, who introduced high-priced efficiency studies into the workplace with a stopwatch and a clever method of analysis. In contrast, scientific management in philosophy finds more resonance with the ideas of the American pragmatist John Dewey, who conceived management as a species of intelligent inquiry, or scientifically-modeled problem solving. While these accounts are not entirely accurate, they do provide depictions of two thinkers with strikingly different visions of scientific management. However, this reading is the result of filtering Taylor’s ideas through recent commentaries, mostly critical, of mainstream management and consulting practices. Likewise, the view that Dewey understood management as a form of inquiry is the result of contemporary interpretations of his work. In the first two sections of this paper, I examine the similarities and differences between Dewey and Taylor’s conceptions of scientific management. Dewey’s critique of scientific management in his book Democracy and Education receives attention in the second section. In the third section, I consider how approaches to organizational theory and public management have moved away from Taylorism, reflecting several of Dewey’s critical insights about scientific management and a more recent alternative: human relations theory. The paper concludes with some final thoughts concerning the usefulness of the Dewey-Taylor comparison and its implications for good governance in a democratic society.
Principles of Chemotherapy in Hodgkin Lymphoma

Hodgkin lymphoma (HL) is highly responsive to combination chemotherapy and cure rates approach 75–80% with modern therapy, in which chemotherapy is almost always employed. In this chapter, we discuss the five standard chemotherapy regimens commonly used for the treatment of HL as well as their side-effect profiles, including late side effects, which may be seen many years after the administration of chemotherapy. Two new agents not yet commercially available will also be discussed.
Correction of the coagulation defect in hemophilia A mice through factor VIII expression in skin

To test the hypothesis that factor VIII expressed in the epidermis can correct hemophilia A, we generated transgenic mice in a factor VIII–deficient background that express human factor VIII under control of the involucrin promoter. Mice from 5 transgenic lines had both phenotypic correction and plasma factor VIII activity. In addition to the skin, however, some factor VIII expression was detected in other tissues that have stratified squamous epithelia. To determine whether an exclusively cutaneous source of factor VIII could correct factor VIII deficiency, we grafted skin explants from transgenic mice onto mice that are double knockouts for the factor VIII and RAG-1 genes. Two graft recipients had plasma factor VIII activity of 4% to 20% of normal and improved whole blood clotting compared with factor VIII–deficient mice. Thus, expression of factor VIII from the epidermis can correct hemophilia A mice, thereby supporting the feasibility of cutaneous gene therapy for systemic disease.
Algebraic properties of some parallel processor interconnection networks

Interconnection networks form an integral part of parallel processing systems, providing the facility for communication between several concurrently executing tasks. This paper presents an algebraic characterization of the sets of communication paths that a network can simultaneously establish between the processing elements of the system. This characterization provides a uniform framework for the analysis of interconnection networks and is shown to yield answers to several important questions concerning the capabilities, limitations and operation of these networks. The networks considered include one way and two way shift register rings, near neighbor meshes, single stage switching networks and briefly, multistage switching networks.
Givenness and Locality

Constituents that encode information that was made salient by prior context often remain unaccented. This paper presents evidence that in order for a constituent to be marked as given by deaccenting, it is not sufficient that it is given, it must be given relative to something else. In particular, I will argue that constituents have to be given relative to their sister. This first section outlines the problem that earlier approaches to givenness face: sometimes, but not always, it appears that the sister of a constituent is relevant in deciding whether it can be marked as given.
All-optical wavelength shifting of combined baseband and subcarrier signals using SOA cross-gain compression

Summary form only given. We have demonstrated all-optical /spl lambda/shifting of combined baseband and control signals using semiconductor optical amplifier (SOA) cross-gain compression. We found that the subcarrier modulation depth must be increased if the combined baseband and control signals are to be /spl lambda/-shifted and detected.
Efficient real-time concurrency on low-cost microcontrollers

Advanced compiler methods squeeze more-efficient concurrency from generic processors, extending their reach and reducing the need for dedicated logic such as ASICs and FPGAs. Software thread integration creates implicitly multithreaded functions, which improves performance and enables more sophisticated programs on less expensive processors.
Transient performance model for parallel and distributed systems

In studying or designing parallel and distributed systems one should have available a robust analytical model that includes the major parameters that determine the system performance. Jackson networks have been very successful in modeling parallel and distributed systems. However, Jackson networks have their limitations. In particular, the product-form solution of Jackson networks assumes steady state and exponential service centers with certain specialized queueing discipline. In this paper, we present a performance model that can be used to study the transient behavior of parallel and distributed systems with finite workload. When the number of tasks to be executed is large enough, the model approaches the product-form of Jackson networks (steady state solution). We show how to use the model to analyze the performance of parallel and distributed systems. We also use the model to show to what extent the product-form solution of Jackson networks can be used.
Age-associated declines in immune system development and function: causes, consequences, and reversal.

Understanding why we age and how that process can be delayed or reversed are topics that have engaged both researchers and the general public [1]. From a scientific perspective, aging is a fascinating biologic question, and knowledge of this process will undoubtedly provide insights into fundamental cellular mechanisms. The subject also intrigues us all because aging affects everyone. If we can find strategies to improve the health of the aged, it would have enormous societal implications, since meeting the medical needs of the growing population of elderly is a huge challenge. Aging affects multiple organs, but its effects on the immune system are among the best studied. One reason for this is that developing and mature lymphoid cells are easily isolated and manipulated in developmental and functional assays in comparison to cells from other tissues. Furthermore, as pointed out by Liu and Sharpless, lymphoid cells persist for extended periods and thus are particularly susceptible to environmental insults that may lead to age-associated defects. These are being increasingly defined. For example, there is a general consensus that declines in immune function with age make the elderly more susceptible to infectious agents, such as influenza, with increasing morbidity and mortality. Furthermore, as reviewed by McElhaney and Effros, vaccination is less efficient in aged individuals. Thus, a better understanding of age-induced immune senescence may lead to the development of strategies to circumvent impaired immunity and other limitations of aging and to improve human health-span. The chapters in this volume of Current Opinion in Immunology provide a broad perspective on the effects of aging on the immune system. As a result, individuals familiar with this area will obtain the latest information from experts in the field, while readers new to the discipline will gain a perspective on how aging affects lymphocyte production and function. In the following sections we highlight some of the questions addressed in the various chapters and issues in need of further investigation.
MEASUREMENT OF IMPINGING JET HEAT TRANSFER UTILIZING INFRARED TECHNIQUES

A heat transfer jet impingement facility (HJIF) was designed and developed in order to determine the overall surface heat transfer pattern due to the impingement of a turbulent jet. Turbulent jets of air in a standard air atmosphere were investigated for their surface impingement characteristics with various nozzle configurations. The HJIF was used to compare the heat transfer performance of the different impingement nozzles using infrared measurements of the impingement surface temperature. Rapid and accurate measurements utilizing this technique were possible.
Ultrafast Amplification of DNA on Plastic Microdevices for Forensic Short Tandem Repeat Analysis

The majority of microfluidic devices used as a platform for low-cost, rapid DNA analysis are glass devices; however, microchip fabrication in glass is costly and laborious, enhancing the interest in polymeric substrates, such as poly (methyl methacrylate) (PMMA), as an inexpensive alternative. Here, we report amplification in PMMA polymerase chain reaction (PCR) microchips providing full short tandem repeat profiles (16 of 16 loci) in 30-40 min, with peak height ratios and stutter percentages that meet literature threshold requirements. In addition, partial profiles (15 of 16 loci) were generated using an ultrafast PCR method in 17.1 min, representing a ~10-fold reduction in reaction time as compared to current amplification methods. Finally, a multichamber device was demonstrated to simultaneously amplify one positive, one negative, and five individual samples in 39 min. Although there were instances of loci dropout, this device represents a first step toward a microfluidic system capable of amplifying more than one sample simultaneously.
Stagnant film model for concentration polarization in membrane systems

The stagnant film model is used almost universally to describe bulk mass transfer (concentration polarization) in pressure-driven membrane systems. However, the mathematical justification for this model, and in particular the logarithmic dependence on the solute concentration and the form of the mass transfer coefficient, remains a point of considerable confusion. This communication presents a more rigorous development of the stagnant film model, providing a much firmer mathematical justification for this approach as well as a more quantitative description of the limitations of this model. Specific calculations are provided for fully developed laminar flow in a parallel plate device and for unsteady mass transfer in an unstirred batch system. In addition, the effects of a concentration-dependent viscosity and diffusivity on the stagnant film analysis are examined, yielding new insights into the proper form of the stagnant film model under these conditions.
Scaling breaking with a dipole pomeron and the growth of proton-proton total cross-section

Using the Mueller formalism, the effect of the conjecture that the coupling of the dipole pomeron is strong only in the double Regge diagrams on the behavior of the inclusive spectrum of pions in the central region, the rising of the inelastic proton-proton cross section at the ISR energies, and the asymptotic behavior of the average multiplicity. For this purpose the Mueller expansion in the central region is used assuming that the leading singularity (pomeron) is a dipole with intercept 1. (JFP)
Quasielastic pion scattering in the (3,3) resonance region

After qualitative discussion of what can be expected in quasielastic ($\ensuremath{\pi}, {\ensuremath{\pi}}^{\ensuremath{'}}$) experiments, a semiclassical model is developed. The mean free path for pion absorption in nuclear matter is a more or less unknown ingredient of the model, but the predictions for the effective nucleon number are insensitive to it. The uncertainties of nuclear corrections can be largely avoided by considering ratios of quasielastic cross sections between different nuclei.
Influence of 17β-estradiol and progesterone on GABAergic gene expression in the arcuate nucleus, amygdala and hippocampus of the rhesus macaque

Abstract Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain, and the responsiveness of neurons to GABA can be modulated by sex steroids. To better understand how ovarian steroids influence the GABAergic system in the primate brain, we evaluated the expression of genes encoding GABA receptor subunits, glutamic acid decarboxylase (GAD) and a GABA transporter in the brains of female rhesus macaques. Ovariectomized adults were subjected to a hormone replacement paradigm involving either 17β-estradiol (E), or E plus progesterone (E + P). Untreated animals served as controls. Using GeneChip® microarray analysis and real-time RT-PCR (qPCR), we examined gene expression differences within and between the amygdala (AMD), hippocampus (HPC) and arcuate nuclei of the medial basal hypothalamus (MBH). The results from PCR corresponded with results from representative GeneChip® probesets, and showed similar effects of sex steroids on GABA receptor subunit gene expression in the AMD and HPC, and a more pronounced expression than in the MBH. Exposure to E + P attenuated GAD1 , GAD2 and SLC32A1 gene expression in the AMD and HPC, but not in the MBH. GABA receptor subunit gene expression was generally higher in the AMD and HPC than in the MBH, with the exception of receptor subunits ɛ and γ2. Taken together, the data demonstrate differential regulation of GABA receptor subunits and GABAergic system components in the MBH compared to the AMD and HPC of rhesus macaques. Elevated ɛ and reduced δ subunit expression in the MBH supports the hypothesis that the hypothalamic GABAergic system is resistant to the modulatory effects of sex steroids.
Electrical resistivity and microstructural changes accompanying the isothermal decomposition of austenite in eutectoid steel

Isothermal transformation diagrams derived by optical metallography and by electrical resistance changes were compared. Incubation periods and the onset of the various transformations, as determined by these two methods, were in close agreement. However, the 100 pct transformation times that were determined by optical metallography always preceded those determined by the resistance method. The time differences between these data increased with decreasing temperature. This may be accounted for in terms of composition adjustments which are not possible to observe metallographically. The acceleration of the onset of the lower bainite reaction at temperatures approaching theM s temperature was also observed.
Gamma Irradiation of Active Self-Healing PLGA Microspheres for Efficient Aqueous Encapsulation of Vaccine Antigens

Purpose To investigate the effect of γ-irradiation of poly(lactic-co-glycolic acid) (PLGA)/Al(OH)3/0 or 5 wt% diethyl phthalate (DEP) microspheres for active self-healing encapsulation of vaccine antigens.
Theory and Limitations of Genetic Network Inference from Microarray Data

Since the advent of gene expression microarray technology more than 10 years ago, many computational approaches have been developed aimed at using statistical associations between mRNA abundance profiles to predict transcriptional regulatory interactions. The ultimate goal is to develop causal network models describing the transcriptional influences that genes exert on each other (via their protein products), which can be used to predict network disruptions (e.g., mutations) leading to a disease phenotype, as well as the appropriate therapeutic intervention. However, microarray data measure only a small component of the interacting variables in a genetic regulatory network, as cells are known to regulate gene expression via many diverse mechanisms. Although many researchers have acknowledged the questionable interpretation of statistical dependencies between mRNA profiles, very little work has been done on theoretically characterizing the nature of inferred dependencies using models that account for unobserved interacting variables. In this work, we review the theory behind reverse engineering algorithms derived from three separate disciplines-system control theory, graphical models, and information theory-and highlight several mathematical relationships between the various methods. We then apply recent theoretical work on constructing graphical models with latent variables to the context of reverse engineering genetic networks. We demonstrate that even the addition of simple latent variables induces statistical dependencies between non-directly interacting (e.g., co-regulated) genes that cannot be eliminated by conditioning on any observed variables.
Analysis of influenza specific CTL responses in children using fibroblasts as stimulator and target cells

Abstract Determination of cytotoxic T lymphocyte (CTL) responses in humans by traditional assays have been restricted by the volumes of blood needed and the nature of the target cells used for the assays. A number of technological advances have recently been described which improve quantitation and sensitivity of the assays. We are developing the concept of using fibroblasts as permissive targets for respiratory viruses in CTL assays. Methods: Fibroblasts can be grown from dispersed nasal epithelium obtained from adenoids. These cells infected with influenza are used as a stimulator layer for lymphocytes. They also can form the target for CTLs in a chromium release assay. Results: Comparison showed fibroblasts to be comparable to influenza infected lymphocytes as stimulators and to EBV transformed lymphocytes as targets. Cells from 25 adenoids have been explored in the fibroblast CTL system with about half of the cryoperserved peripheral blood lymphocytes showing CTL activity and mucosally associated CTLs being found in one patient. Conclusions: Exploration of new CTL targets that may be adapted not only to chromium release assays but to newer CTL assays offers the promise of developing a practical way of defining the CTL response in young children to natural infection and to varying immunization strategies. This may allow us to put in perspective CTLs as a correlate of immunity to influenza in humans.
Identification of circumsporozoite proteins in individual malaria-infected mosquitoes by Western blot analysis

Circumsporozoite (CS) proteins of rodent (Plasmodium berghei), simian (P. knowlesi), and human (P. falciparum) malaria parasites extracted from dead and dried mosquitoes have been identified by the Western blot (immunoblot) technique. Dried mosquitoes which were laboratory-reared and infected with Plasmodium or freshly dissected sporozoites were triturated in sample reducing buffer and the extracts electrophoresed in a 10% SDS-polyacrylamide gel. After transferring the proteins to nitrocellulose, the molecular weights of both precursor and surface CS proteins of the plasmodial species were identified by probing with homologous monoclonal antibodies followed by 125I-labeled anti-mouse IgG. The molecular weights of the CS proteins extracted from dried mosquitoes were identical to those of CS proteins extracted from viable sporozoites. Immunoblot analysis is sensitive in that it can detect as few as 100 sporozoites. This technique is of epidemiological significance because it permits the identification of CS proteins of different plasmodial isolates extracted from individual, dried field-collected mosquitoes.
Aspects of Self-Regulation and Self-Structure as Predictors of Perceived Emotional Distress:

Research on the link between the self and emotional distress has produced many measures that have unknown conceptual and empirical interrelations. The authors identified two classes of self-related variables shown previously to be important predictors of emotional distress. The first class, termed self-regulatory variables, included ego-resiliency, ego-control, ego-strength, and hardiness. The second class, termed self-structure variables, included self-complexity, self-discrepancy, self-consistency, self-attitude ambivalence, and role conflict. Using a two-step structural equation modeling (SEM) strategy, the authors examined first the factor structure of this set of measures. Second, they determined that Elasticity and Permeability (two self-regulatory factors) accounted for unique variance in the prediction of perceived emotional distress (Agitation and Dejection), whereas Self-Discrepancy and Self-Complexity (two self-structure factors) did not.
Growth of Epitaxial ZnO:Mn/ZnO:V Heterostructures and Ferroelectric-ferromagnetic Characterization

The wide band gap semiconductor ZnO is well known for its multifunctionality in the form of ferromagnetism (FM), piezoelectricity, and magneto optics. ZnO has been found to grow with intrinsic oxygen deficiencies which in turn are believed to give ferromagnetism and high conductivity in this material. Doping Zn 2+ sites by V 5+ ions creates a mixed valency as well as strain in the original ZnO hexagonal structure because of the reduced ionic size of vanadium. The mixed valency creates charge polarity between Zn-O and V-O bonds. This charge polarity and the rotation of the nonlinear V-O bonds with respect to Zn-O bonds under electric field have been shown to produce ferroelectricity. Furthermore, Mn doping of ZnO has also shown enhancement in ferromagnetic properties in ZnO. For this material to be a viable ferromagnetic material the magnetic properties should not be from segregated phases. In the present study we have grown undoped, Mn, and V doped ZnO thin films using pulsed laser deposition (PLD). ZnO target with 2% atomic Mn doping and a target with 0.5% atomic V doping were prepared by solid state reactions and sintering. Films were grown both epitaxially on sapphire substrates and in polycrystalline form on silicon substrates. Magnetization measurements by the PPMS showed M vs. H hysteresis loops with saturation for all ZnO: Mn films. V doped films showed high saturation polarization for film deposited at high pressures. We have also fabricated epitaxial bilayers of ZnO:V/ZnO:Mn on sapphire substrates. Ferroelectric and ferromagnetic properties of these heterostructures are presented.
Parameterized framework for the analysis of visual quality assessments using crowdsourcing

The ability to assess the quality of new multimedia tools and applications relies heavily on the perception of the end user. In order to quantify the perception, subjective tests are required to evaluate the effectiveness of new technologies. However, the standard for subjective user studies requires a highly controlled test environment and is costly in terms of both money and time. To circumvent these issues we are utilizing crowdsourcing platforms such as CrowdFlower and Amazon's Mechanical Turk. The reliability of the results relies on factors that are not controlled and can be considered “hidden”. We are using pre-test survey to collect responses from subjects that reveal some of the hidden factors. Using statistical analysis we build parameterized model allowing for proper adjustments to collected test scores.
Changes in the level of apoptosis-related proteins in Jurkat cells infected with HIV-1 versus HIV-2

Human immunodeficiency virus (HIV) infection-induced apoptosis of infected CD4 T cells as well as uninfected (bystander) CD4 T cells and other types of cells is a major factor in the pathogenesis of AIDS. Clinically, HIV-2 patients have a higher CD4 cell count at the time of an AIDS diagnosis, and generally have longer survival after development of symptoms. The mortality after an AIDS diagnosis has been reported to be more influenced by CD4 cell count than HIV type. Previous studies have shown significant variations in cytopathic effects following in vitro infection with primary isolates of HIV-1 or HIV-2 subtypes; however, the relative contributions of HIV-1 and HIV-2 infection leading to cell death remain unclear. Using a human cell line, Jurkat, we examined differences in key molecules involved in apoptotic signaling pathways during infection with either HIV-1 or HIV-2. HIV-1 infection generated more reactive oxygen species (ROS), increased the expression of a larger number of molecules involved in cell signaling such as p47, p38α, JNK, c-Yes, total PKC, and decreased the expression of molecules such as p38β, ERK1/2, and XIAP relative to HIV-2 infection. HIV-1 induced a higher degree of cell death through stronger activation of both apoptotic pathways. HIV-1 infection downregulated both Bcl-XL and FLIP expressions at later time points postinfection, while HIV-2 infection dramatically upregulated both Bcl-XL and FLIP expression. We also found that the expression of Bcl-XL or FLIP resulted in significant inhibition of HIV replication in Jurkat cells. These findings suggest that HIV-1 infection with high levels of cytotoxicity results in a higher level of cell death through apoptosis during a short time postinfection. The longer period of infection observed with HIV-2 with a lower degree of cytotoxicity was accompanied by increased Bcl-XL and FLIP expression. High protein levels of Bcl-XL or FLIP inhibit HIV replication and may be one explanation for the clinical observation that HIV-2 infected patients generally tend to be long-term nonprogressors with high CD4 lymphocyte counts compared with HIV-1 infected persons.
The oxidation and leaching of some chromia-alumina and chromia-silica-alumina preparations

Abstract The oxidation and leaching of some chromia-alumina and chromia-silica-alumina preparations have been studied. A correlation has been found between ionic potential of a number of ions used as promoters on a chromia-alumina, and the amount of equivalent CrO 3 leached from these preparations after oxidation at 500 °. The correlation is good for ions having inert gas electron configurations. Those ions having pseudo-inert gas configurations fit the correlation as well. A study of extended oxidation and leaching shows that a limit of oxidizability of chromia on alumina can be reached. However, this limit is closely approached while much of the clump chromia is still present. This is shown by electron spin resonance spectra. The presence of dispersed phase chromia is also shown. The loss of oxidizability is related to activity in dehydrocyclization of n -hexane and is explained in terms of accumulated surface acidity. The effect of potassium promotion on oxidizability and dehydrocyclization activity has also been studied.
The influence of urea on the kinetics of interfacial transfer

The phase transfer kinetics of methyl nicotinate (2-pyridine carboxylic acid, methyl ester) across a water-isopropyl myristate interface have been determined in the presence and absence of a large concentration of urea dissolved in the aqueous phase. Using a rotating diffusion cell, rate constants have been measured at four temperatures covering the range 20–37°C; the temperature dependence of the kinetics has enabled the thermodynamic parameters for interfacial transfer to be derived. Although urea appeared to have little effect on the rate of solute transfer organic → aqueous at the concentration used (6M), it was found to reduce the rate constant in the opposite direction by a factor of two. The free energy barrier (ΔG⦵#,±) to transfer at the interface was relatively insensitive to the presence of urea; however, the favorable entropic contribution to (ΔG⦵#,±) was significantly reduced when urea was introduced into the system. Interpretation of the results is proposed in which both the solute solvation behavior and the relative ordering of the interface with and without urea present are taken into consideration.
Risk factors for neurocognitive dysfunction after cardiac surgery in postmenopausal women.

Background Women are at higher risk than men for neurologic complications from cardiac operations. This study identified risk factors for neurocognitive dysfunction after cardiac operations in elderly women. Methods One hundred thirteen postmenopausal women undergoing primary coronary artery bypass grafting, with or without valve operation, underwent psychometric testing and neurologic evaluation the day before operation and 4 to 6 weeks postoperatively. Risk factors assessed for neurologic complications included atherosclerosis of the ascending aorta and apolipoprotein e4 genotype. Postoperative neurocognitive dysfunction was defined as the composite end point of a one standard deviation decrement from baseline on two or more psychometric tests or a new neurologic deficit. Results Neurocognitive dysfunction was present in 25% of the women 4 to 6 weeks postoperatively. Women with a neurocognitive deficit tended to be older than those without a deficit (72.1 ± 8.1 vs 69.4 ± 8.9 years, p = 0.144) and were more likely to have mild atherosclerosis of the ascending aorta, a history of congestive heart failure, longer duration of cardiopulmonary bypass (CPB) and aortic cross-clamping, lower nadir blood pressure during CPB, higher rates of postoperative atrial fibrillation, and longer postoperative hospitalization. Mild atherosclerosis of the ascending aorta, duration of CPB, duration of aortic cross-clamping ( p = 0.051), and length of postsurgical hospitalization were independently associated with postoperative neurocognitive dysfunction. Conclusions Mild atherosclerosis of the ascending aorta, duration of CPB, aortic cross-clamping time, and length of hospitalization, but not apolipoprotein e4 genotype, identified risk for neurocognitive dysfunction after cardiac operation in postmenopausal women.
SH3 Domains Specifically Regulate Kinase Activity of Expressed Src Family Proteins

The Src homology 2 (SH2) and Src homology 3 (SH3) domain are approximately 50% conserved in various Src family kinase members. Several lines of evidence suggest that in Src these domains are sequence motifs that direct substrate recognition, regulate kinase activity, or control subcellular localization. We sought to investigate the function of the homology domains in human Lyn, and to determine whether the differences between various SH3 domains affect function. To do this, we generated variant forms of Lyn lacking SH2 and SH3 domains, and created chimeras in which the SH3 domains in human c-Src and Lyn were replaced with SH3 domains from other family members. In contrast to similar deletions in Src, forms of Lyn lacking SH2 or SH3 had decreased kinase activity. The SH3 chimeras all had individual characteristics. Insertion of the Blk SH3 domain into Lyn restored kinase activity, while insertion of the Fyn or Src SH3 into Lyn enhanced the kinase activity 2-3-fold. Insertion of the Lyn SH3 into Src also doubled kinase activity. Expression of the Lyn-Src SH3 chimera in mammalian cells induced cell transformation. This study 1) demonstrates that the regulation of Lyn is different than Src, and 2) provides new evidence that despite their homology, there are important functional differences between the SH3 domains of the various Src family members.
Age and Position of Lower Devonian Graptolite Zones Relative to the Appalachian Standard Succession

The monograptid fauna extends almost to the top of the Lower Devonian in the Old World, but monograptids do not occur in the Lower Devonian succession of New York or elsewhere in the central or southern Appalachians. Monograptid occurrences in the northern Appalachians are too sparse to demonstrate equivalence of any Old World graptolite zone with a definite level in the New York succession. Three Lower Devonian graptolite zones occur in sequence interbedded with shelly and conodont-bearing carbonate rocks in central Nevada. The Nevada succession, coupled with an auxiliary succession at Royal Creek, Yukon Territory, Canada, can be correlated with the Appalachian Lower Devonian standard according to New York terminology, principally on the basis of brachiopods and conodonts. Allowing for relatively small, eventually correctable errors of inexactness, the Monograptus uniformis Zone correlates with the Coeymans Limestone, the M. praehercynicus Zone with the New Scotland Formation, and the M. hercynicus Zone with the Becraft Limestone. The position of the Monograptus yukonensis Zone corresponds to the Oriskany-Esopus interval. These correlations will provide the basis for a continent-wide evaluation of paleogeography and tectonism in terms of chronostratigraphic units smaller than series for the first time.
Alphaviruses — vectors for the expression of heterologous genes

Abstract DNA viruses and retroviruses are well established as vectors for the expression of heterologous genes, but there is increasing interest in the possibilities of using RNA viruses, which do not replicate through a DNA intermediate, for this purpose. This article summarizes some of the general properties of RNA viruses and concentrates on one class of RNA viruses — the alphaviruses — and their potential as expression vectors.
A test of randomness for finite spatial distributions

-A statistical method is presented for determining randomness of points spatially distributed in two-dimensional space. The procedure is based on a dtstance-to-particle (nearest neighbor) model derived from an elementary Poisson process. In a previous derivation of the method, an extension to the model was proposed and used without adequate empirical justi£ication. Herein the test is derived in detail and its performance evaluated with Monte Carlo simulations. Results indicate that the model extension provides adequate representations when the n d hypothesis is true.
Protoplanetary core formation by rain-out of minerals

Models of giant protoplanets computed by DeCampli and Cameron (1979) show that Fe and other minerals in the planet interior are in a liquid state during one of the stages of protoplanet evolution. A model of coalescence of liquid drops was developed using the 'stochastic' collection equation of Slattery (1978); the growth times to droplets was much shorter than the period during which the drops are in a liquid state. Brownian collection quickly coalesced the tiny droplets to a radius of 0.005 cm; gravitational collection was required to form droplets of radii greater than 0.005 cm.
A rapid method for exploring the protein structure universe

We have developed an automatic protein fingerprinting method for the evaluation of protein structural similarities based on secondary structure element compositions, spatial arrangements, lengths, and topologies. This method can rapidly identify proteins sharing structural homologies as we demonstrate with five test cases: the globins, the mammalian trypsinlike serine proteases, the immunoglobulins, the cupredoxins, and the actinlike ATPase domain-containing proteins. Principal components analysis of the similarity distance matrix calculated from an all-by-all comparison of 1,031 unique chains in the Protein Data Bank has produced a distribution of structures within a high-dimensional structural space. Fifty percent of the variance observed for this distribution is bounded by six axes, two of which encode structural variability within two large families, the immunoglobulins and the trypsinlike serine proteases. Many aspects of the spatial distribution remain stable upon reduction of the database to 140 proteins with minimal family overlap. The axes correlated with specific structural families are no longer observed. A clear hierarchy of organization is seen in the arrangement of protein structures in the universe. At the highest level, protein structures populate regions corresponding to the all-alpha, all-beta, and α/β superfamilies. Large protein families are arranged along family-specific axes, forming local densely populated regions within the space. The lowest level of organization is intrafamilial; homologous structures are ordered by variations in peripheral secondary structure elements or by conformational shifts in the tertiary structure. Proteins 1999;34:317–332. © 1999 Wiley-Liss, Inc.
Scalable preconditioned conjugate gradient inversion of vector finite element mass matrices

Mass matrices arise in the numerical solution of time-dependent partial differential equations by the Galerkin method. Since these systems must be inverted at each time step, rapid inversion algorithms for these systems are important. When nodal finite elements are used as basis functions, it is known that the mass matrices can be consistently approximated by a diagonal matrix or solved by a scalable conjugate gradient method. This may not be the case for other basis functions. In this paper, we show that the preconditioned conjugate gradient method is scalable when used to invert mass matrices that arise from vector finite element basis functions. These basis functions are particularly important for solving Maxwell's equations on unstructured grids by the Galerkin method.
Code elaboration and self-concept states.

Summary A study was conducted to explore the relationship between selected aspects of language and the self. The semantic differential and the Twenty Statements Test were administered to high school students in two urban settings. A rationale for using the TST both as a measure of self and as a language task is presented. The results of analysis showed that code elaboration was inversely related to self-esteem and positively related to derogation. These associations are interpreted as a consequence of the type of social interaction made possible by code elaboration.
Stochastic phase space dynamics with constraints for molecular systems.

Constraining fast degrees of freedom and using a Langevin-like description of the dynamics are standard tools to simulate complex systems that allow for comparatively large time steps in the numerical integration of the equations of motion. Here we start with the Hamiltonian description of classical mechanics for the incorporation of stochastic and frictional forces. Constraints are incorporated into Hamiltonian dynamics following a procedure put forward by Dirac. Combining these two approaches, in general, requires a different treatment of the constraints from that which is usually done in deterministic dynamics. The numerical algorithm we chose for the integration of these equations is a second-order Runge-Kutta scheme modified by a Euler treatment for the constraints. The resulting algorithm is stable up to large time steps and generates averages in the canonical ensemble. The applicability of the method to the simulation of large molecular systems is shown for a melt of n-${\mathrm{C}}_{13}$ alkane chains by a comparison to results from a Nos\'e-Hoover molecular dynamics simulation.
Beta and gamma subunits of a yeast guanine nucleotide-binding protein are not essential for membrane association of the alpha subunit but are required for receptor coupling.

Abstract Conditions were devised to demonstrate GTP-regulated coupling between the yeast STE2-encoded receptor and its cognate guanine nucleotide-binding protein (G protein). Treatment of partially purified membranes with guanosine 5'-[gamma-thio]triphosphate (GTP[gamma-S]) converted the receptor from a high-affinity state (Kd = 17 nM) to a much lower affinity state (Kd approximately 150 nM), as judged by three independent criteria: rate of ligand (alpha-factor) dissociation, equilibrium binding, and antagonist competition. Expression of STE2 from the GAL1 promoter in MATa/MAT alpha diploids, which do not express GPA1 (encoding G protein alpha subunit, G alpha), STE4 (encoding G protein beta subunit, G beta), and STE18 (encoding G protein gamma subunit, G gamma) but do express another G protein alpha subunit (product of GPA2), yielded a single class of low-affinity receptors that were GTP[gamma-S]-insensitive, indicating that STE2 gene product cannot couple productively with other G proteins, even in the absence of competition by its cognate G protein. By using gpa1, STE4, and ste18 mutations, it was found that all three G protein subunits were required for functional coupling, as judged by the absence of high-affinity receptors when any of the three gene products was altered. This finding demonstrates that G beta and G gamma subunits are essential for formation of a productive complex between a G alpha subunit and its corresponding receptor. Wild-type STE4 and STE18 gene products were not essential for membrane localization of the GPA1 gene product, as indicated by cell fractionation and immunological analyses, suggesting that G beta and G gamma subunits interact with the receptor or make the G alpha subunit competent to associate correctly with the receptor, or both.
Functional anatomy of the cardiac nerves in the baboon.

In 17 anesthetized baboons, the autonomic innervation of the heart was carefully exposed and electrically stimulated to determine the course of fibers having direct inotropic and/or chronotropic actions. The superior cervical and nodose ganglia are intimately associated by means of short but large interconnections, and the sympathetic and parasympathetic trunks descend with the carotid artery in a common epineural sheath. The middle cervical ganglion is invariably well defined and completely separated from the vagus trunk in the upper portion of the thoracic cage. Direct nervous connections between the sympathetic and vagal trunks are frequent at all levels within the thorax. Both systems also send small nerves into the phrenic and recurrent laryngeal nerves. Separate inferior cervical and first thoracic ganglia were not found, but rather, a large and well defined stellate ganglion extending across the heads of the first and second ribs. The stellates are connected to the middle cervical ganglia by means of both dorsal and ventral ansae subclavia of varying size. Although fine nerves arising from the upper thoracic trunk were located, they appeared to have no direct inotropic or chronotropic actions. The major sympathetic and parasympathetic nerves converge upon richly interconnected dorsal and ventral cardiopulmonary plexuses and several minor (superior vena cava, left atrial, pulmonary veins) plexuses. Both ipsilateral and contralateral control of cardiac function is possible through these pathways. The baboon cardiac innervation thus appears to resemble that of man in some respects and the dog in others.
Impacts of mountaintop mining on terrestrial ecosystem integrity: identifying landscape thresholds for avian species in the central Appalachians, United States

Context Mountaintop removal/valley fill (MTR/VF) mining in the central Appalachians is a major driver of landscape change within terrestrial ecosystems.