cssi/SciSciGPT-SciSciNet huggingface dataset:
Structured turing machines

A structured decomposition theorem for Turing machines is given. The nature of the building blocks and the form of the connections allowed suggest a parallel to the Bohm-Jacopini theorem on structured flowcharts. Thus in a broadest sense, there is obtained an independent machine-theoretic restatement of the fundamental precepts of structured programming. At the same time, the characteristics of the decomposition offer several obvious advantages over known results of this type. In particular, the building blocks (the “simple” machines) are seen to perform total and regular word functions. Furthermore, the connections themselves should prove to be useful as pedagogical tools in the Turing machine theory and as a theoretical framework for top-down machine (or algorithmic) design.
A developmental genetics-inspired approach to robot control

The need to build modular, scalable, and complex technology capable of adaptation, self-assembly, and self-repair has fuelled renewed interest in using approaches inspired by developmental biology. To meet this need, a new field, called Computational Development (CD), has emerged. Its focus is on adapting processes and mechanisms from developmental biology so as to help us build scalable, complex technology. Due to the embryonic nature of the field, however, research investigating the potential of such approaches for different problem domains is crucial to its success. In this paper, the plausibility of applying a developmental biology-inspired approach to the demanding problem domain of reactive robot control is explored. Using developmental genetics as a source of inspiration, a model of genetic regulatory networks is used in conjunction with a spatially distributed evolutionary algorithm to evolve real-time robot controllers for tasks such as general purpose obstacle avoidance.
Changes in lower eyelid resting position, movement, and tone with age

In a study of lower eyelid movement, resting position, and tone in 185 normal white patients ranging in age from 15 to 89 years, the mean vertical eyelid excursion from downgaze to upgaze was 5.29 mm. There was, however, a decrease in vertical eyelid movement with age of 0.05 mm/yr. The mean horizontal lower eyelid excursion with eyelid closure or gentle blink was 3.3 mm and horizontal eyelid movement decreased 0.015 mm/yr. The decrease in vertical and horizontal eyelid movement with aging was closely correlated with the increase in eyelid laxity in elderly patients (P
ALTERATIONS IN THEOPHYLLINE (T) METABOLISM DURING THE FIRST YEAR OF LIFE

Maturational changes in T pharmacokinetics were evaluated in 45 infants; postconceptional age (PCA) 30.9-95.7 wks. After achievement of steady-state on T maintenance therapy, multiple serum and urine samples were obtained over dosing interval and assayed by HPLC for T and metabolites: caffeine (C), 1-methyluric acid (1MU), 3-methylxanthine (3MX), 1,3-dimethyluric acid (1,3MU). Mean(SD) T clearance (Cl) increased significantly (p 50 wks from 21.9(6.3) to 26.6(7.7) and 57.7(17.6). ml/hr/kg, respectively. Concomitant decrease (p 0.10) were found in some infants up to 55 weeks PCA. Stepwise multiple regression analysis showed urinary excretion of 3MX to be the primary parameter explaining the change in both T Cl (r=0.81, p<0.01) and serum C/T ratio (r=0.66, p<0.01). Urinary excretion of 3MX (demethylated) for the 3 PCA groups was 1.4, 4.2 and 13.1% compared to 23%, 41% and 44% for 1.3MU (oxidative). Disappearance of serum C and maturation of T metabolism is dependent on development of demethylation pathway which does not occur until approximately 55 wks PCA. Prior to that age, serum C concentration should be monitored in patients receiving T.
'Til death do us part': coming to terms with symbiotic relationships

Symbiotic interactions of microorganisms are widespread in nature, and support fundamentally important processes in diverse areas of biology that range from health and disease to ecology and the environment. Here, David Relman discusses the selection of articles in this Focus issue, which reflects the exciting advances in our understanding of intimate partnerships between organisms and their environments.
Cooperation and the cooperativeness of the other player

The strategy choices, the number of cooperative versus competitive choices, constituted one dependent variable. The amount of winnings constituted a second response measure. A third response measure consisted of ratings of the confederate made by the subject. The subject responded to 18 traits divided into four categories: (1) motive traits-traits indicative of motives likely to be aroused by the game situation (for example: generous, cooperative, stubborn, greedy, accommodating, and willing to compromise); (2) sociometric traits-traits indicative of social attractiveness (for example: likable, desirable as a friend, roommate, or date, and favorable personality); (3) ability traits (for example: capable, orderly, efficient, intelligent, and effective); and (4) personality traits-traits indicative of some degree of personality disorder (for example: neurotic, anxious, emotionally unstable, and nervous). The subject rated the confederate on a nine-point scale on each trait.
Degradation of commercial azo dyes in water using ozonation and UV enhanced ozonation process

The chemical oxidation of eight non-biodegradable azo dyes by ozonation and photooxidation process was studied in a pilot scale photochemical (UV/ozone) reactor. In experiments with ozone bubbling, the degradation of eight azo dyes was found to occur in the absence of UV light. The degradation rate of azo dyes was observed to be first order with respected to both azo dye and ozone concentrations. The pH of the solution decreased while the azo dyes degraded. UV light did not significantly enhance the degradation ability of the ozonation reaction under various conditions. No degradation was observed when the azo dye solution was irradiated by UV light alone. Effects of ozone dosage, and initial concentrations of azo dyes are discussed. Time for removal of 50 % of azo dye and rate constants can be used to determine the decomposition rate of each azo dye by different oxidation processes as a function of various conditions.
Investigation of a strut/endwall interaction in supersonic annular flow

A combined experimental and numerical investigation of strut/endwall interactions within an annular duct having a supersonic core flow has been conducted. Four diamond-shaped struts with a 7 deg half angle were positioned circumferentially equidistant within an annular duct having a gap height of 0.7 strut chords, and an inner-to-outer wall radius ratio of 0.7. Turbulent boundary layers exist on both inner and outer walls of the duct, but have not merged. The core flow upstream of the struts is uniform at a nominal Mach number of 3.0 and a Reynolds number of 3 x 10 exp 5 based on the strut chord length. Experimental results, which include Pitot pressure distributions within the flow field, static pressure distributions on the inner and outer walls of the duct, and oil flow visualization on the centerbody and strut, are presented and compared with CFD predictions. Secondary flows associated with the interactions are examined including the trajectories of the horseshoe vortices formed at the leading and trailing edges of the strut and the trajectories of the vortices formed in the corner of the strut/endwall intersection.
Basic Capabilities of Man and Machine in Respect to Automated Checkout

The basic capabilities and limitations of men and machines are discussed, as they relate to automated testing of aerospace vehicles. Operators and technicians are discussed from psychological and physiological viewpoints, and present automatic checkout equipment is discussed in respect to in-system performance. Both general and specific capabilities and limitations are discussed. The views presented are based upon an extensive survey of field applications of automatic checkout equipment.
Conformations of poly(d(A-T-T))-poly(d(A-A-T)).

The sodium salt of poly[d(A-T-T)]·poly[d(A-A-T)] is observed in oriented and partially crystalline fibers to have the classical B -DNA molecular conformation at relative humidities >85% and the B -type D -form hitherto observed only for poly[d(Pur-Pyr)]·poly[d(Pyr-Pur)] DNAs, at relative humidities of zero to 85%. No A -type conformation is observed.
The Fundamentals of Performance Based Training in Aviation

In today's ever changing aviation community, the human contribution to accidents or mishaps can be minimized through the use of performance based training. The process of developing realistic performance based training has little to do with expenditures on the latest high tech equipment and software packages and everything to do with management's commitment to conducting a critical assessment of the individual vocation or job. Identification of the essential performance elements is necessary to develop a thoughtful, logical, and progressive training guide/syllabus and instructional strategy. A key component to performance based training is the extensive and appropriate use of the five senses: sight, hearing, touch, smell, and taste. The appropriate incorporation of the senses in performance based training strengthens understanding of the job task, provides an imprint of a work process or procedure, and allows for feedback and confirmation of new knowledge while insuring longer retention of subject matter. A structured performance based training program can be adapted to any job description in the aviation industry, requiring only a commitment to train employees in a manner which closely resembles real life demands of
The Exclusion of Black Women from National Leadership Positions in the United States: Taxation with Limited Representation

This article claims that the United States is progressing well when examined through the racial and cul- tural diversity of its young people aged 29 and younger with earned doctorates. The data show that fe- males in general and Asian and Black females in particular are earning very high proportions of doctorate degrees among individuals aged 29 and younger in 2009 and 2008. For example, of the 117,000 doctorate degrees (Ph.D., Ed.D., etc.) held by individuals in the US aged 25 - 29 in 2009, females accounted for 65,000 (55.6%), with Black females and Asian females accounting for 11.1% (13,000) and 10.3% (12,000) respectively. In 2008, of the 14,000 doctorate degrees (Ph.D., Ed.D., etc.) held by individuals aged 18 - 24 in the US, females accounted for 11,000 (78.6%), and Black females and Asian females each accounted for 4000 (28.6%). The article points out, however, that while high levels of educational attainment is shown to result in Asian, White and Hispanic women being elected or appointed to the United States Sen- ate, Governor’s Office and the United States Supreme Court, Black American women continue to be ex- cluded from these three national leadership positions—Taxation Without Representation.
The α2 adrenergic agonist, dexmedetomidine, selectively attenuates ischemia-induced increases in striatal norepinephrine concentrations

Abstract This study was designed to evaluate the ability of a selective α2 adrenergic agonist (dexmedetomidine) to attenuate ischemia-induced increases in striatal norepinephrine, 3 methoxy-4-hydroxyphenethyleneglycol (MHPG), dopamine, and 5-hydroxyindoleacetic acid (5-HIAA). Following the induction of anesthesia with halothane and oxygen, microdialysis catheters were stereotacticly inserted into the striatum of 9 New Zealand white rabbits. Monitored variables included epidural temperature, arterial blood gases and pH, mean arterial pressure, blood glucose concentrations and the electroencephalogram. Following collection of baseline samples of dialysate, animals were randomized to receive a continuous infusion of saline (n = 4) or dexmedetomidine (n = 5). Cerebral ischemia was produced by the inflation of a neck tourniquet and induction of deliberate hypotension. Dialysate collection continued during the ischemic period and for the ensuing 140 min of reperfusion. All dialysate was frozen at −80°C prior to its analysis by liquid chromatography for catecholamine content. There were no significant differences between the two groups for temperature, arterial blood gases, or mean arterial pressure. Blood glucose concentrations increased in the dexmedetomidine group. The electroencephalogram became isoelectric within 30 s of tourniquet inflation in all animals. Analysis of the norepinephrine and MHPG levels revealed significantly lower values for the dexmedetomidine-treated group during and following the ischemic period. There were no differences between groups for extracellular dopamine or 5-HIAA concentrations. These results suggest that the α2 agonist dexmedetomidine can selectively attenuate ischemia-induced increases in striatal norepinephrine concentrations.
Radiocarbon “dating” of individual chemical compounds in atmospheric aerosol: First results comparing direct isotopic and multivariate statistical apportionment of specific polycyclic aromatic hydrocarbons

Abstract Recent instrumental developments which allow radiocarbon (14C) determinations on microgram quantities of organic material have revolutionized our ability to apportion fossil and biogenic sources of trace carbonaceous gases and aerosols in the environment. The chemical complexity of carbonaceous aerosol, however, presents a challenge in the interpretation of its average isotopic composition. For this reason, there has long been an interest in radiocarbon measurements of specific classes of compounds, or even individual trace compounds of particular environmental concern, such as the polycyclic aromatic hydrocarbons (PAHs). The PAHs hold special interest because they are produced at trace levels in combustion processes; they exhibit compound-specific genotoxicity; and they have the potential to serve as “molecular markers” or tracers for specific ambient aerosol sources. Prior to the work reported here, inferences from ambient studies concerning molecular tracer capabilities have been indirect, relying on circumstantial evidence and/or multivariate statistical techniques. In the present study we demonstrate, for the first time, the ability to measure the 14C content of individual, trace organic compounds (PAHs) in atmospheric aerosol. The research utilized a special, well characterized atmospheric reference material, where individual PAHs were radiocarbon “dated” using off-line gas chromatography/accelerator mass spectrometry (GC/AMS). Separation of individual compounds in sufficient amounts for AMS was accomplished by automated preparative capillary gas chromatography (PCGC). Results showed the PAHs dated to be primarily fossil in origin, and lent support to an earlier multivariate statistical study suggesting that benzo[ghi]perylene might serve as a useful tracer for soot generated by motor vehicles, although this assessment must be viewed as tentative because of potential interference from other compounds incompletely removed from the purified PAH fraction.
Flow Velocity Acceleration in the Left Ventricle: A Useful Doppler Echocardiographic Sign of Hemodynamically Significant Mitral Regurgitation

Doppler echocardiography is a sensitive method to detect mitral regurgitation in patients with both native and prosthetic valves. However, estimates of the amount of mitral regurgitation remain semiquantitative, and even severe mitral regurgitation may be underestimated in the presence of markedly eccentric regurgitant jets or acoustic shadowing of the left atrium by mitral or aortic prostheses. This report describes the Doppler findings in 10 patients with severe native valve mitral regurgitation (angiographic grade III or IV) and in 15 patients with severe bioprosthetic mitral regurgitation that required valve replacement. An increase in peak mitral flow velocity above normal values was seen in eight of 10 patients with severe native valve mitral regurgitation (≥ 130 cm per second) and 11 of 15 patients with severe prosthetic valve mitral regurgitation (≥210 cm per second). One of 10 patients with a native valve and four of 15 patients with a bioprosthetic valve appeared to have only a localized left atrial systolic flow disturbance, incorrectly suggesting that the mitral regurgitation was mild. However, in all patients with severe mitral regurgitation, a low velocity (
Early postnatal development of the rat accessory olfactory bulb

A volumetric study of the accessory olfactory bulb (AOB) in rats aged from birth (P0) to postnatal day 60 (P60) was conducted. AOB volume increased 600% from P0 to P18 and then declined, so that by P60, it was 66% of its maximum value. The growth of individual laminae paralleled overall AOB development, except for the internal plexiform layer, which continued to grow. The number of output neurons in the mitral cell layer declined after P18, while the total number of granule cells in the internal granular layer rose 300% from P0 to P18, but then did not change significantly through P60.
Ecology and Economics of the Great Plains

'Working from an impressive, sweeping, and thorough array of facts, Licht builds a bedrock-solid argument for restoration of our country's heartland. America ought to read it, and America ought to do it' - Richard Manning, author of "Grassland". '"Ecology and Economics of the Great Plains" is a well worked out proposal for the midsection of the country to restore its biodiversity while simultaneously improving the regional and national economy' - Deborah Popper, The College of Staten Island. The Great Plains were once characterized by vast expanses of grass, complex interdependence among species, and dynamic annual changes due to weather, waterways, and fire. It is now generally accepted that less than one percent of the original tallgrass prairie remains. Habitat fragmentation, the loss of natural predator-prey associations, changes in species composition, and various commercial practices continue to threaten grassland biodiversity.Recently scholars and conservationists have discussed opportunities for large-scale restoration projects in the Great Plains, but they have provided few details. Daniel Licht offers here a bold new approach to restoring and conserving the grassland ecosystem. In describing hypothetical reserves, he explains how they could help conserve grassland biodiversity, reduce federal expenditures on agriculture, increase recreational opportunities, and sustain rural economies outside the reserves. Daniel S. Licht is a fish and wildlife biologist at Fort Snelling, Minnesota. His articles have appeared in "Prairie Naturalist" and "Great Basin Naturalist".
Effects of Dissolved Calcium on Arsenate Sorption at the Kaolinite-Water Interface

The effects of dissolved calcium (Ca) on arsenate (As(V)) reactivity and surface speciation at the kaolinite-water interface were studied as a function of pH using pseudo-equilibrium adsorption/ desorption experiments and extended X-ray absorption fine-structure spectroscopy (EXAFS) analyses. The EXAFS analyses indicated that As(V) tetrahedral molecules were coordinated on aluminum octahedral via bidentate binuclear (E3.11 A ˚ ) bonding at pH 4.5 to 6.75 and total As loading levels of 978 to 1,783 Kmol/L kg j1 . There was no evidence for As(V)-Ca ternary species when both As(V) and Ca were present (0.68Y1.3 mmol/L). In the adsorption experiments, As(V) adsorption gradually increased with increasing pH and decreased at pH above 6. Interestingly, As(V) sorption was suppressed when 1 mmol/L of Ca was added to the systems at pH 4 to 8. The As(V) desorption was also pronounced when the systems contained Ca. These macroscopic results indirectly suggest that the weakly sorbed As(V) surface species are outcompeted by the ion-exchange process of Ca at the broken edge site of kaolinite. Results of macroscopic data and EXAFS analysis suggest that both outer-sphere and inner-sphere surface As(V) species might coexist on kaolinite surfaces. In predicting the dissolved As(V) in subsurface environments, weakly sorbed As(V) species might be in- fluenced by not only anionic species, but also cationic species in soil solutions and in pore water. Quantifying the effects of various sorbed cations may be important in predicting arsenic transport processes in subsurface environments.
The role of matrix metalloproteinases in intestinal epithelial wound healing during normal and inflammatory states.

Background Healing of the epithelium is a key consideration in gastrointestinal surgery. Inflammation is one factor innate to patients with inflammatory bowel disease that poses a risk of delayed healing of the intestinal epithelium postoperatively. Materials and Methods Epithelial wounding model was performed on rat intestinal epithelial cells grown under control and interferon gamma (IFN-γ)-, interleukin-1beta (IL-1β)-, and tumor necrosis factor-alpha (TNF-α)-stimulated conditions. Wounds were measured and percent healing was calculated at 0, 8 and 24 h. Western blot analysis was performed using matrix metalloproteinase (MMP)-7 primary antibody and semiquantitative densitometry was conducted. Results Wounds were 50.0% and 99.7% healed under control conditions at 8 and 24 h, respectively. IL-1β and IFN-γ delayed wound closure. MMP-7 increased by 2.3-fold at 8 h and 1.6-fold at 24 h during wound healing. Activated MMP-7 increased by 3- to 5-fold at 24 h. IL-1β stimulation increased levels of MMP-7 by 17% to 37% above the elevated expression due to healing alone. TNF-α up-regulated MMP-7 in non-wounded and wounded cells, and IFN-γ did not affect its expression. When MMP-7 activity was blocked, wound closure was delayed. Conclusions MMP-7 significantly contributes to intestinal epithelial wound closure evidenced by: (1) presence of increased MMP-7 during healing under control conditions and (2) the delayed rate of closure when MMP-7 activity was blocked. IL-1β increased MMP-7 levels beyond those seen during normal healing. It appears that some increase in MMP-7 is necessary for normal wound closure; however, its overexpression may delay intestinal epithelial wound healing, especially when MMP-7 is up-regulated by cytokines present in the inflammatory environment of inflammatory bowel disease (IBD).
Parametric identification of a servo-hydraulic actuator for real-time hybrid simulation

Abstract In a typical Real-time Hybrid Simulation (RTHS) setup, servo-hydraulic actuators serve as interfaces between the computational and physical substructures. Time delay introduced by actuator dynamics and complex interaction between the actuators and the specimen has detrimental effects on the stability and accuracy of RTHS. Therefore, a good understanding of servo-hydraulic actuator dynamics is a prerequisite for controller design and computational simulation of RTHS. This paper presents an easy-to-use parametric identification procedure for RTHS users to obtain re-useable actuator parameters for a range of payloads. The critical parameters in a linearized servo-hydraulic actuator model are optimally obtained from genetic algorithms (GA) based on experimental data collected from various specimen mass/stiffness combinations loaded to the target actuator. The actuator parameters demonstrate convincing convergence trend in GA. A key feature of this parametric modeling procedure is its re-usability under different testing scenarios, including different specimen mechanical properties and actuator inner-loop control gains. The models match well with experimental results. The benefit of the proposed parametric identification procedure has been demonstrated by (1) designing an H ∞ controller with the identified system parameters that significantly improves RTHS performance; and (2) establishing an analysis and computational simulation of a servo-hydraulic system that help researchers interpret system instability and improve design of experiments.
G456(P) Improving the diagnostic process and delivery of interim intervention for pre-school autism spectrum disorder children in a developmental clinic

Introduction Autism Spectrum Disorder (ASD) is increasingly common, and the department we work in is a key diagnostic and interim service provider for ASD among pre-school children. To improve the diagnostic process and delivery of interim intervention services for children and families referred to our department for ASD, we established an interdisciplinary ASD team, which initiated a Clinical Practice Improvement Project (CPIP) in September 2007 to provide an “ASD track” service. In this paper, we share our learning from this project. Methods The ASD team analysed the root cause through cause and effect analysis. We derived solutions which improved 1) case differentiation mechanism and prioritisation of services, 2) standardisation of diagnostic processes and documentation, 3) continuity of care and case management, 4) cross-disciplinary training and professional standards, 5) family-centeredness of our interim intervention services. We conducted 3 Plan-Do-Check-Action (PDCA) cycles (January 2010–April 2011) before implementing the ASD track service in May 2011. Results This paper presents results of our implementation. From September 2011 to March 2012, 181 cases were referred to the ASD team from the DCD triage clinic. Of these, 93 were classical ASD and offered the fast-track diagnostic service, for which 73(78.5%) underwent 2-hour psychological assessment. Compared to the non-track process, the ASD track achieved 1) reduced default rates of 17.7%, 2) 45% reduction in psychological assessment duration, 3) 64.4% reduction in wait time for psychological assessment, 4) 63.3% reduction in ASD psychological assessment cycle time, 5) 32.8% reduction in ASD diagnostic process cycle time, 6) 28.1% reduction in clinic time usage, 7) enhanced case management and delivery of interim intervention services in family-centred manner. (Illustration – Improvements of ASD Track from Old Process) Conclusions The ASD track improved the diagnostic process and delivery of interim intervention service for Autism Spectrum Disorder in our department.
DNA excision repair and transcription: implications for genome evolution

The past two years have seen a substantial increase in knowledge regarding the enzymology of DNA excision repair. These data support a growing body of information which suggests that transcribed nucleotide sequences are preferentially subject to excision repair. It is possible that these mechanisms, or related ones, are relevant to the molecular evolution of sequences that appear not to evolve according to models which do not take into account regional sequence differences in the extent of DNA repair.
The Role of Self-Esteem and Social Influences in Aggressive Reactions to Interactional Injustice.

Two experiments were conducted to examine the potential negative consequences an organization may face in response to perceptions of interactional injustice. Study 1 found that one potentially negative reaction to perceived injustice can be intended retaliation. In addition, study 1 found that individuals with high self-esteem are most likely to respond negatively to a perceived injustice by indicating that they plan to engage in a retaliatory response. Study 2 explored the effects of one’s situation on intended retaliation behavior. The results again indicate that perceptions of interactional injustice are strongly related to intended retaliation behavior. In addition, the study demonstrates that one’s group can have a significant influence on the perceptions of injustice and one’s subsequent reactions to these injustices.
The polarity of axon growth in the wings of Drosophila melanogaster

We have analyzed the growth of axons in the wings of the mutants Hairy wing and hairy of Drosophila melanogaster. These mutants produce many supernumerary bristle organs and sensilla campaniformia, whose axons grow between the two wing epithelia and can be visualized in both pupal and adult stages. The sensory axons of wild-type animals follow two paths in the wing, within longitudinal veins L1 and L3, and always grow with a distal to proximal polarity. In the mutants, all axons following these two paths likewise grow with correct polarity. Axons elsewhere in the wing, however, are found to grow in many different directions, including from proximal to distal and hence directly away from the central nervous system. A variety of patterns of axon growth and fasciculation are seen in different individuals. Only if the supernumerary axons encounter the two normal paths do they reliably grow toward the base of the wing. We conclude that these two paths provide polarity information for axon growth, information which is either not used or not available elsewhere in the wing in spite of the obvious morphological polarization of every epithelial cell. The time course of neural differentiation suggests that the normal sensory cells of mutant wings, which grow axons relatively early, may be the source of polarity information for the later-differentiating supernumerary cells.
HAP1 and intracellular trafficking

Huntington's disease is caused by a polyglutamine expansion in the protein huntingtin. Several studies suggest that huntingtin and its associated protein HAP1 participate in intracellular trafficking and that polyglutamine expansion affects vesicular transport. A study now provides new evidence that HAP1 is also involved in the endocytosis of membrane receptors. These studies offer insight into the normal function of HAP1 and its involvement in Huntington's disease.
The Application of Perdeuterated Polycyclic Aromatic Hydrocarbons (PAH) as Internal Standards for the Liquid Chromatographic Determination of PAH in a Petroleum Crude Oil and Other Complex Mixtures

Abstract A sequential liquid chromatographic (LC) procedure for the determination of polycyclic aromatic hydrocarbons (PAH) in a petroleum crude oil and other complex mixtures is described. The procedure includes normal-phase LC on an aminosilane column to isolate fractions containing isomeric PAH and reversed-phase LC on a polymeric C18 column to separate the individual PAH isomers. Appropriate perdeuterated PAH are added to the sample so that each isomeric fraction will contain one internal standard. The perdeuterated PAH are excellent internal standards for this sequential LC procedure. Perdeuterated PAH have normal-phase and reversed-phase LC retention characteristics similar to those of the parent PAH. In the normal-phase LC separation, the perdeuterated PAH elute in the same fraction as the parent PAH. In the reversed-phase LC separation, the perdeuterated PAH elute first and are generally resolved from the parent PAH. The optimized spectrofluorometric detection of each PAH analyte is accomplished b...
The use of PIPES buffer in the fixation of mammalian and marine tissues for electron microscopy.

SUMMARY PIPES, an organic based buffer, was used in the preparation of a variety of marine and mammalian tissues for electron microscopic study. The ultrastructural results demonstrate that this buffer renders superior ultrastructural details to those obtained with some of the more common inorganic buffers especially when long fixation times are required. Furthermore, this buffer system does not appear to contribute extraneous anions or cations to the tissues and thus permits accurate elemental determinations to be performed on thin sections of the plastic embedded specimens by means of energy dispersive X-ray analysis.
The Role of Cell Calcium Overload in Nephrotoxic Renal Tubular Cell Injury

Data on the role of cell Ca ++ overload in the pathogenesis of nephrotoxic renal tubular injury and methodologic considerations for studying this process were reviewed. It was concluded that: (1) A consistent pattern of Ca ++ uptake and resultant functional changes are attributable to the interactions of Ca ++ with mitochondria during their isolation, unless specific measures are taken to prevent these interactions. (2) The simplest approach to prevent in vitro Ca ++ from occurring during isolation of mitochondria from injured tissues having high Ca ++ levels is to include ruthenium red in the homogenizing solution used to prepare the mitochondria, although this will still permit some surface binding of Ca ++ to mitochondria. (3) By comparing mitochondrial Ca ++ levels and functional parameters of mitochondria isolated after in vivo nephrotoxic injury with those of control mitochondria isolated at similar homogenate Ca ++ levels, the components of mitochondrial Ca ++ overload and functional deterioration solely attributable to in vivo events can be identified. These were detailed for gentamicin- and mercuric chloride-induced nephrotoxicity. (4) Tissue and mitochondrial Ca ++ overload are relatively late events during the development of renal tubule cell injury secondary to aminoglycosides or to mercuric chloride, occurring only when lethal cell injury is present by morphologic criteria. (5) Since it correlates with lethal cell injury, the presence of tissue Ca ++ overload can be of value in assessing this process, but care must be exercised in drawing conclusions about the extent of lethal cell injury, because the degree of Ca ++ overload can be modified by factors, such as saline intake, independently of changes in the number of lethally injured cells.
Early structural valve deterioration of the mitroflow aortic bioprosthesis

There has been a trend toward more frequent use of bioprosthetic valves, especially in the young generations, over the last decade.1,2 According to the Society of Thoracic Surgeons database, use of bioprosthetic valve increased from 44% in 1996 to 78% in 2006 in North America.1 Freedom from warfarin use and restrictions on diet and activities make bioprosthetic valves more attractive and popular, and multiple reports have shown that choosing a bioprosthetic valve does not decrease survival despite the increased rate of reoperation.3,4 Article see p 2012 The Mitroflow aortic prosthesis (Sorin Group Inc) is one of the most frequently used bioprostheses, with >100 000 implanted worldwide.5 The bovine pericardium is mounted externally around the stent, which maximizes the flow relative to the stent size. The valve is placed in the supra-annular position compared with the intra-annular position in some of the other bioprostheses. These characteristics allow superior valve hemodynamics in the Mitroflow aortic valve, especially in those with a small aortic annulus (19 and 21 mm)6; therefore, the Mitroflow aortic valve is considered an ideal valve for patients with a small aortic root. The Achilles heel of the bioprosthetic valve is structural valve deterioration (SVD). Cusp tears and thickening, calcification, pannus formation, and thrombus lead to deterioration of the valve,7 which is the leading reason for reoperation in bioprosthetic valves. The rate of SVD differs among ages; valves implanted in younger patients degenerate faster. For patients >65 years of age, the 10-year freedom from SVD in new pericardial valves is typically >90%.8 In this issue of Circulation , Senage et al9 strike a note of warning …
Stiffness Degradation and Time to Cracking of Cover Concrete in Reinforced Concrete Structures Subject to Corrosion

Corrosion-induced cracks in reinforced concrete (RC) structures degrade the stiffness of the cover concrete. The stiffness degradation is mainly caused by the softening in the stress-strain relation in the cracked concrete. Limited efforts have been made to model the cracking and the corresponding effects on the cover concrete, despite of its importance in assessing and modeling the behavior of RC structures. This paper proposes a stiffness degradation factor to model the stiffness degradation of the cover concrete subject to cracking. The proposed factor is computed in terms of the cracking strain corresponding to the maximum opening of the concrete cracks based on an energy principle applied to a fractured RC structure. The time to cracking of the cover concrete is then determined as the time from the corrosion initiation needed by the crack front to reach the outer surface of the cover concrete. The proposed stiffness degradation factor and the method to compute the time to cracking are illustrated through two numerical examples. The times to cracking of the cover concrete that are predicted using the proposed method are in agreement with the measured values from laboratory experiments.
Scanning Electron Microscopy and Energy Dispersion Microanalysis of Metallographically Polished Dental Amalgam Surfaces

The microstructures of copper- and zinc-containing dental amalgams and nonzinc dental amalgams were examined. The three major phases were distinguishable without etching. The silver-mercury phase exhibited considerable substructure; some of the inclusions found had high concentrations of copper or zinc. Generally, zinc was distributed more uniformly than copper when both were present.
Microfabrication of a resistance temperature detector by freshman engineering students

A hands-on microfabrication project was developed and implemented for Louisiana Techpsilas integrated freshman engineering curriculum. The project involved the design and fabrication of a simple nickel resistance temperature detector. The project is part of a series of hands-on projects being developed for the freshman engineering curriculum as part of a "Living with the Lab" concept that utilizes a microcontroller-based robotics kit to increase experiential learning. The project was initially piloted in two sections of a freshman engineering course and was extended to seven sections in the current academic year. The project included the direct application of fundamental engineering topics as well as applied technical skills and additionally provided an opportunity to introduce students to some common microfabrication techniques. The sensors were fabricated using optical lithography and etching of a nickel coated microscope slide. Students interfaced the sensors with microcontrollers and calibrated the sensors. The project provided an opportunity for freshman students to gain first-hand experience in the design, fabrication and calibration of a temperature sensor as well as motivated the need for engineering tools such as spreadsheets and CAD packages. The paper presents assessment results for the projectpsilas impact on student knowledge and interest in micro and nanotechnology.
An inhibitor of protein synthesis in cytoplasmic extracts of density inhibited cells

Cytoplasmic extracts of green monkey kidney-Vero M3 cells that have been grown to high cell density and have entered the stationary phase of growth lose the capacity to synthesize proteins after they have been frozen and thawed. The same loss of protein synthetic capacity is not observed when cytoplasmic extracts of low cell density Vero M3 or HeLa S-3 cells are frozen and thawed before assay, nor when high cell density Vero M3 cell extract is assayed without having been frozen. The loss of the protein synthesis capacity of the frozen and thawed extracts of stationary phase Vero M3 cells is accounted for by the appearance of an inhibitor. The inhibitor is precipitated in the 30 to 70% ammonium sulfate fraction of the 100,000 g supernatant. It is inactivated by heat and is non-dialyzable. It blocks the transfer of amino acids from tRNA to growing peptide chains. The amount of this inhibitor in the extract (measured by relative inhibition of in vitro protein synthesis) increases as a function of the density of the cells from which the extract was made, and the increase can be correlated with the progressive turnoff of protein synthesis in whole cells.
Optimal pain management after aortic valve implantation: an opportunity to improve outcomes after transapical access in the future?

Ten years after transcatheter aortic valve implantation (TAVI) was pioneered by Alain Cribier in 2002, it has been accepted as an alternative treatment for aortic stenosis. The PARTNER–US trial, in which the Edwards Sapien (Edwards Lifesciences, Irvine, California, USA) transcatheter heart valve (THV) was used and the mortality risk for surgical aortic valve replacement (AVR) was jointly estimated by the heart team (cardiologist and cardiac surgeon), is the first prospective randomised trial on TAVI. Results demonstrate superiority of TAVI compared with medical treatment, in patients with an estimated AVR mortality of 50% or greater (cohort B).1 Cohort A results confirm that TAVI also compares to AVR in patients seen to be at high risk of open heart surgery (AVR mortality estimated ≥15% to <50%).2 So far the vast majority of TAVI has been performed through transfemoral and transapical access. Until recently, the Edwards Sapien was the only THV with CE mark accreditation for transapical TAVI, and is still the only device that has been approved by the US Food and Drug Administration. Alternative access routes through the subclavian artery and ascending aorta are currently being explored and offer additional treatment opportunities. The extensive European TAVI experience using the Edwards Sapien THV has been reported previously and the SOURCE Registry, the largest European TAVI registry, demonstrated favourable outcomes for transfemoral and transapical access.3 ,4 In contrast to the transfemoral approach, transapical TAVI is not restricted by size and quality of the iliofemoral arteries and therefore inclusion criteria for the two access routes are different. This results in a higher risk profile for the transapical group and may explain the slightly higher 30-day (10.3% vs 6.3%) and 1-year mortality (27.9% vs 18.9%) found in SOURCE for transapical patients.3 ,4 This view …
MnOx-CeO2 mixed oxides prepared by co-precipitation for selective catalytic reduction of NO with NH3 at low temperatures

Abstract A series of manganese-cerium oxide catalysts were prepared by co-precipitation method and used for low temperature selective catalytic reduction (SCR) of NO x with ammonia in the presence of excess O 2 . These catalysts were characterized by X-ray diffraction (XRD), surface area measurement and FTIR. The experimental results showed that the best Mn-Ce mixed-oxide catalyst yielded 95% NO conversion at 150 °C at a space velocity of 42,000 h −1 . As the manganese content was increased from 0 to 40% (i.e. the molar ratio of Mn/(Mn+Ce)), NO conversion increased significantly, but decreased at higher manganese contents. The most active catalyst was obtained with a molar Mn/(Mn+Ce) ratio of 0.4. Only N 2 rather than N 2 O was found in the product when the temperature was below 150 °C. At higher temperatures, trace amounts of N 2 O were detected. A mechanistic pathway for this reaction was proposed based on earlier findings and FTIR results obtained in this work. The initial step was the adsorption of NH 3 on Lewis acid sites of catalyst, followed by reaction with nitrite species to produce N 2 and H 2 O. Possible intermediates are proposed and all the intermediates could transform into NH 2 NO, which could further react to produce N 2 and H 2 O.
Lattice Boltzmann Simulation of Viscoelastic Liquid Bearing in Head-Disk Interface: A Three-Dimensional Model

In order to keep pace with the demand of higher recording density of hard disk drive (HDD), further reduction in head-media spacing is needed. In addition to make the thinner overcoat and lubricant film, reducing the fly height is an alternative key step. Two possible candidates for next generation HDDs are quasi-contact recording and viscoelastic liquid bearing (VLB). In the first approach, the slider operates in the mixed region between sliding and flying. The modeling of the lubrication of the quasi-contact recording requires complex molecular design of both thin liquid films and air flows. In the VLB technology, an incompressible liquid film is used for the lubrication instead of conventional air bearing. Such a liquid lubrication can avoid the contact of the slider and disk, which has a very "stiff" bearing and high shock resistance. The standard mathematical modeling of lubrication for VLB has been reported in the past decades. In this paper, a novel computational tool based on lattice Boltzmann methods (LBM) is adopted to simulate the lubrication for head-disk interface using a non-Newtonian fluid model in three dimensions. LBM is a versatile numerical tool for simulating fluid flows containing complex physics phenomena. The numerous advantages including clear physical pictures, an inherently transient nature, multi-scale simulation capabilities, and fully parallel algorithms make LBM to be an attractive candidate as a next generation head-disk interface (HDI) simulation tool.
Palatability and Selected Related Characteristics of Three Types of Roasted Porcine Muscle

SUMMARY: A completely randomized design was followed to evaluate 48 roasts posterior third of the loin) from 12 Duroc and 12 Poland China barrows. Antemortem treatment of pigs produced “normal”, pale-soft-exudative (PSE) and dark-firm-dry (DFD) longissimus dorsi (LD) muscle. Meat was roasted at 350°F to an internal temperature of 167°F and evaluated by organoleptic and selected objective measurements. There was no significant organoleptic preference for one type (“normal”, PSE, DFD) of LD. Also, differences among types of muscle were not significant for roasting time, volume of press fluid or total moisture (press method); whereas roasting losses, total moisture (Brabender) and pH of LD were affected significantly by type of muscle. In general, there were significant (P < 0.05) differences between PSE and DFD muscle, and between “normal” and DFD muscle. DFD muscle exhibited the smallest roasting loss and greatest total moisture, whereas PSE muscle had the greatest roasting loss and least total moisture. DFD muscle rated highest in pH and lowest in Warner-Bratzler shear value. LD from Durocs was more tender (P < 0.05), had a higher (P < 0.05) pH, and contained less (P < 0.01) total moisture (Brabender) than LD from Poland Chinas. Cooking losses were greater (P < 0.05) for roasts from Durocs than for roasts from Poland Chinas.
A successive parameter estimation algorithm for chirplet signal decomposition

In ultrasonic imaging systems, the patterns of detected echoes correspond to the shape, size, and orientation of the reflectors and the physical properties of the propagation path. However, these echoes often are overlapped due to closely spaced reflectors and/or microstructure scattering. The decomposition of these echoes is a major and challenging problem. Therefore, signal modeling and parameter estimation of the nonstationary ultrasonic echoes is critical for image analysis, target detection, arid object recognition. In this paper, a successive parameter estimation algorithm based on the chirplet transform is presented. The chirplet transform is used not only as a means for time-frequency representation, but also to estimate the echo parameters, including the amplitude, time-of-arrival, center frequency, bandwidth, phase, and chirp rate. Furthermore, noise performance analysis using the Cramer Rao lower bounds demonstrates that the parameter estimator based on the chirplet transform is a minimum variance and unbiased estimator for signal-to-noise ratio (SNR) as low as 2.5 dB. To demonstrate the superior time-frequency and parameter estimation performance of the chirplet decomposition, ultrasonic flaw echoes embedded in grain scattering, and multiple interfering chirplets emitted by a large, brown bat have been analyzed. It has been shown that the chirplet signal decomposition algorithm performs robustly, yields accurate echo estimation, and results in SNR enhancements. Numerical and analytical results show that the algorithm is efficient and successful in high-fidelity signal representation
Special Education Teacher Preparation in Classroom Management: Implications for Students with Emotional and Behavioral Disorders.

Special education teachers’ skills with classroom organization and behavior management affect the emergence and persistence of behavior problems as well as the success of inclusive practice for stu...
Ultra-low RF linewidth in a quantum dot mode-locked laser under external optical feedback stabilization

The effect of external optical feedback on quantum dot two-section passively mode-locked lasers is investigated. The RF linewidth narrows down from 8 KHz in the free-running situation to a very low value of 350 Hz.