cssi/SciSciGPT-SciSciNet huggingface dataset:
Skeletal muscle ventricle pressure-volume properties conform to dynamic and static conditioning

Abstract Background Chronic changes in skeletal muscle ventricle (SMV) size and strength can directly affect performance and stability. These changes may depend on the conditioning protocol or implant system. Therefore the effects of conditioning protocols on SMV geometry and contractility must be identified for optimal SMV design and application. Methods Skeletal muscle ventricles were constructed in 14 goats using the left latissimus dorsi muscle. The SMVs were conditioned with a 40 mL constant-volume isovolumetric implant (n = 5, IsoVol group) or a compliant pneumatic system that allowed dynamic shortening and direct exposure to resting pressures. Dynamic SMV resting pressure was either progressively increased from 40 to 100 to 120 mm Hg (n = 5, high pressure [HiP] group) or maintained at 40 mm Hg (n = 4, low pressure [LowP] group) during conditioning. The SMV pressure and volume characteristics were monitored daily. Results All HiP SMVs expanded in volume during conditioning after exposure to physiologic pressures. Three of 4 LowP SMVs decreased in volume during conditioning. Skeletal muscle ventricle passive and active (isovolumetric evoked pressure) pressure-volume curves shifted toward the increasing, stable, and decreasing volumes in HiP, IsoVol, and LowP SMVs respectively. Conclusions Frequent monitoring of SMV characteristics during conditioning enabled progressive pressure training and is a valuable tool to evaluate SMV conformation. Chronic SMV adaptation is dependent on the conditioning protocol or implant system utilized. Demonstration of SMV expansion at physiologic pressures suggests that clinical sized SMVs may be chronically unstable unless a supporting implant system is utilized or SMV compliance is reduced. Therefore the mechanisms effecting chronic expansion should be further defined to optimally design SMVs for clinical implementation.
The volatility of asset returns during trading and nontrading hours: some evidence from the foreign exchange markets

Abstract This paper presents the ratio of the hourly return variance during trading-time to the hourly return variance during nontrading-time for live currency futures contracts. We find that: (1) hourly return variances are greater during trading-time than during nontrading-time, (2) hourly return variances are greater during weeknight nontrading-time than during weekend nontrading-time and (3) the variance ratios are generally highest for the Canadian dollar contracts, lower for the European currency contracts, and lowest for the Japanese yen contracts. The results suggests that the timing of business hours is an important determinant of the timing of currency futures return volatility.
A new class of parallel alternating-type iterative methods

Abstract This paper is concerned with parallel alternating-type iterative methods for solving large sparse linear systems of the form Au = b arising in the numerical solution of partial differential equations by finite difference methods. Examples of alternating-type methods include the alternating direction implicit (ADI) method and the unsymmetric SOR (USSOR) method. Each iteration of an alternating-type method involves the use of two parameters, say ϱ and ϱ ′. We consider parallel alternating-type methods where, given an initial vector u (0) , the positive integer m , and two sets of m parameters “ϱ i ” and “ϱ′ j ” , one carries out m 2 single iterations in parallel, each involving one pair ( ϱ i , ϱ ′ j ) of the parameters. It is shown that in some cases a linear combination v ∗ of the vectors thus obtained is the same as the vector v ∗∗ which would be obtained by a sequential process involving m iterations based on the successive use of the parameter pairs ( ϱ 1 , ϱ ′ 1 ), ( ϱ 2 , ϱ ′ 2 ),…, ( ϱ m , ϱ ′ m ). Thus, the parallel procedure offers the potential of reducing the wall-clock time by a factor of m as compared with the sequential procedure. Preliminary numerical results based on the use of a virtual parallel system of sequential computers confirm the expected reductions in the number of iterations.
Removal of fractured inferior vena cava filters: feasibility and outcomes.

Abstract Purpose To examine the feasibility and outcomes of removing retrievable inferior vena cava (IVC) filters that have fractured. Materials and Methods Retrospective review of IVC filter retrievals over an 8-year period identified patients in whom there was an attempt to retrieve fractured filters and struts. Patient medical records were evaluated for filter type, recovery method for filter body and struts, removal attempt results, and complications. Results Between January 2002 and December 2010, 148 IVC filters were retrieved, 15 of which were fractured. All 15 fractured filter bodies were successfully retrieved. Nine of 15 fractured filters (60%) were removed in their entirety by using endobronchial forceps to retrieve the filter body and/or fractured struts. In three cases, forceps were used to retrieve the filter body and the fractured strut was removed with a snare. In six patients (40%), only the filter body could be removed, three with the Recovery Cone and three with endobronchial forceps. Failed attempts to remove fractured struts were made in three cases, with no attempt made in the remaining three. These struts were incorporated in the right ventricle, embedded in the IVC wall, or extraluminal. Minor caval defect was identified in five of 15 retrievals (33%); mild hemoptysis was noted in one case in which the strut was snared from a pulmonary artery. No major complications occurred. Conclusions Fractured IVC filter bodies can be safely removed. Fractured filter struts can be removed when accessible, but are often in a position that makes retrieval not possible.
Determination of the Rate Constants of Oligomerization of Amyloid-β Peptides using Fluorescence Quenching of Tetramethylrhodamine

Soluble oligomers of amyloid-β (Aβ) play a central role in the pathology of Alzheimer's disease. Here we have determined the rate constants of the monomer-oligomer process of Aβ using a new method based on self-quenching of tetramethylrhodamine (TMR) which is covalently labeled at the N-terminal of Aβ. During aggregation TMR fluorescence is quenched in a time dependent manner in three distinct phases, an early oligomerization phase, a lag phase and a growth phase. Kinetic data of the early phase are consistent with a monomer-dimer-trimer process. The rate and the equilibrium constants differ markedly between Aβ1-42 and Aβ1-40 showing higher oligomerization propensity for A1-42.The association rate constants (∼102 M−1s−1) for both the peptides are slow compared to a diffusion limited process. The rates of oligomerization are altered dramatically with increase of temperature and are highly sensitive to changes in pH especially below pH 7.5. Our results for the first time provide quantitative estimation of the kinetics of monomer-oligomer process of Aβ. The methodologies presented here are simple and therefore can be easily applied to other amyloidogenic proteins.View Large Image | View Hi-Res Image | Download PowerPoint Slide
Diversity of Mn oxides produced by Mn(II)-oxidizing fungi

Manganese (Mn) oxides are environmentally abundant, highly reactive mineral phases that mediate the biogeochemical cycling of nutrients, contaminants, carbon, and numerous other elements. Despite the belief that microorganisms (specifically bacteria and fungi) are responsible for the majority of Mn oxide formation in the environment, the impact of microbial species, physiology, and growth stage on Mn oxide formation is largely unresolved. Here, we couple microscopic and spectroscopic techniques to characterize the Mn oxides produced by four di!erent species of Mn(II)-oxidizing Ascomycete fungi (Plectosphaerella cucumerinastrain DS2psM2a2, Pyrenochaetasp. DS3sAY3a,Stagonosporasp. SRC1lsM3a, andAcremonium strictumstrain DS1bioAY4a) isolated from acid mine drainage treatment systems in central Pennsylvania. The site of Mn oxide formation varies greatly among the fungi, including deposition on hyphal surfaces, at the base of reproductive structures (e.g., fruiting bodies), and on envisaged extracellular polymers adjacent to the cell. The primary product of Mn(II) oxidation for all species growing under the same chemical and physical conditions is a nanoparticulate, poorly-crystalline hexagonal birnessite-like phase resembling syntheticd-MnO 2 . The phylogeny and growth conditions (planktonic versus surface-attached) of the fungi, however, impact the conversion of the initial phyllomanganate to more ordered phases, such as todorokite (A. strictumstrain DS1bioAY4a) and triclinic birnessite (Stagonosporasp. SRC1lsM3a). Our findings reveal that the species of Mn(II)-oxidizing fungi impacts the size, morphology, and structure of Mn biooxides, which will likely translate to large di!erences in the reactivity of the Mn oxide phases.
The cascade loading of active systems

Abstract The cascade loading of a 2-port by a 1-port is analyzed under the assumption that both systems are linear, continuous, time-invariant, causal, and possibly active. At each port the incident and reflected waves are allowed to be Banach-space-valued distributions. This implies that both systems have convolution representations with unit impulse responses that are operator-valued distributions with supports bounded on the left at the origin. Moreover, the unit impulse response of the 2-port has a 2 × 2 matrix representation. Let s22 be the second-row second-column element of that matrix and let sL be the unit impulse response of the 1-port. It is shown that, if sL is at least as regular as s22 is singular so that s 22 ∗ s L is a continuous operator-valued distribution, then the 1-port resulting from the cascade connection has a uniquely determined scattering operator.
Fast Approximate Graph Partitioning Algorithms

We study graph partitioning problems on graphs with edge capacities and vertex weights. The problems of b-balanced cuts and k-balanced partitions are unified into a new problem called minimum capacity $\rho$-separators. A $\rho$-separator is a subset of edges whose removal partitions the vertex set into connected components such that the sum of the vertex weights in each component is at most $\rho$ times the weight of the graph. We present a new and simple O(log n)-approximation algorithm for minimum capacity $\rho$-separators which is based on spreading metrics yielding an O(log n)-approximation algorithm both for b-balanced cuts and k-balanced partitions. In particular, this result improves the previous best known approximation factor for k-balanced partitions in undirected graphs by a factor of O(log k). We enhance these results by presenting a version of the algorithm that obtains an O(log OPT)-approximation factor. The algorithm is based on a technique called spreading metrics that enables us to formulate directly the minimum capacity $\rho$-separator problem as an integer program. We also introduce a generalization called the simultaneous separator problem, where the goal is to find a minimum capacity subset of edges that separates a given collection of subsets simultaneously. We extend our results to directed graphs for values of $\rho \geq 1/2$. We conclude with an efficient algorithm for computing an optimal spreading metric for $\rho$-separators. This yields more efficient algorithms for computing b-balanced cuts than were previously known.
Molecular characteristics of pediatric patients with sickle cell anemia and stroke.

Cerebrovascular accidents (CVA) are serious complications of sickle cell anemia (SS) in children. Factors that predispose children to this complication are not well established. In an effort to elucidate the risk factors associated with CVA in SS, we have determined the alpha-globin genotype and the beta(S) haplotype of children with this complication. Among 700 children with SS followed at Children's Hospital of Michigan, 41 (6%) are on chronic transfusions because of stroke due to cerebral infarction. The mean age of patients with CVA at the time of stroke was 5.6 +/- 3.2 years (mean +/- SD). The male/female ratio was 2/3. Only 8 of 41 patients (19.5%) had one alpha-gene deletion, compared to the reported prevalence of 30% in African-Americans. None of the patients had two alpha-gene deletions, and two (5%) had five alpha-genes. These findings are different than those in our adult patients with SS, where the prevalence of -alpha/-alpha and alphaalphaalpha/alphaalpha is 4% and <2%, respectively. Ten different beta(S)-haplotypes were detected in the patients studied. The majority of the patients (31%) were doubly heterozygous for the Ben/CAR haplotypes followed by Ben/Ben, Ben/Sen, and CAR/CAR haplotypes, respectively. The prevalence of these haplotypes, with the exception of the CAR/CAR haplotype, was higher in females than males. All the patients with CAR/CAR haplotype were males, had four alpha-genes, and ranked third in prevalence. Three patients were heterozygous for the Cameron haplotype. The Cameron and atypical haplotypes were more prevalent than reported in patients with SS at large. The data suggest that CVA in children seems to occur more frequently in females and in patients with certain beta(S) haplotype. alpha-Gene deletion seems to offer a protective effect against this complication. Neonates with four or more alpha-genes whose beta(S) haplotype is Ben/CAR, atypical, or CAR/CAR seem to be at a higher risk for CAV than other patients. A prospective study on a larger group of patients with or without CVA may clarify this issue.
Inter-receiver fairness: a novel performance measure for multicast ABR sessions

In a multicast ABR service, a connection is typically restricted to the rate allowed on the bottleneck link in the distribution tree from the source to the set of receivers. Because of this, receivers in the connection can experience inter-receiver unfairness, when the preferred operating rates of the receivers are different. In this paper we explore the issue of improving the inter-receiver fairness in a multicast ABR connection by allowing the connection to operate at a rate higher than what is allowed by the multicast tree's bottleneck link. Since this can result in cell loss to some receivers, we operate with the knowledge of each receiver's application-specific loss tolerance. The multicast connection rate is not allowed to increase beyond the point where the cell loss on a path to a receiver exceeds this receiver's loss tolerance. Based on these ideas we develop an inter-receiver fairness measure and a technique for determining the rate that maximizes this measure. We show possible switch algorithms that can be used to convey the parameters needed to compute the function to the connection's source. In addition we develop a global network measure that helps us assess the effect of increasing inter-receiver fairness on the total network delivered throughput. We also briefly explore improving inter-receiver fairness through the use of multiple virtual circuits to carry traffic for a single multicast session. A set of examples demonstrate the use of the inter-receiver fairness concept in various network scenarios.
Myocardial contrast echocardiography can be used to quantify intramyocardial blood volume : New insights into structural mechanisms of coronary autoregulation

Background Changes in intramyocardial blood volume (IBV) mediate autoregulatory adaptations to coronary stenosis. This study investigated whether (1) myocardial contrast echocardiography (MCE) can quantify changes in IBV during coronary stenosis and (2) the relation between coronary resistance– and MCE-derived IBV could yield insight into structural mechanisms of IBV change. Methods and Results A circulating in vitro model with constant flow and varying volume was used to determine whether indicator dilution theory could be applied to MCE. Contrast echo was performed with albumin microbubbles, and time-intensity data were fit to a gamma-variate function. With six different volumes, bubble transit time was linearly related to volume (r=.91). To determine whether changes in IBV could be quantified in vivo, the left anterior descending coronary artery in 12 dogs was instrumented with a flow probe, occluder, and intracoronary pressure catheter, and non–flow-limiting stenoses were created. IBV was derived by u...
Variations in the velocities of the major plates since the late cretaceous

Abstract We present models for the relative and absolute velocities of the major plates from 80 m.y. ago to the present as tests of several alternative plate reconstructions and as a guide in the evaluation of the hypothesis that pronounced changes in plate speeds or directions arise directly from changes in the configuration of plate boundary forces. Digitized plate boundaries were rotated backwards in time using published rotations to determine positions at 5 m.y. intervals back to the late Cretaceous. The oceanic plate boundaries were then corrected so as to properly match magnetic anomalies. Relative plate velocities were obtained by differencing finite rotations. “Absolute” velocities were determined by assuming that no net torque is exerted on the lithosphere. Rms “absolute” speeds of each plate were calculated as functions of time as a conceptually simple measure of plate velocities and accelerations. We have tested several possible reconstructions for the Antarctic and Pacific plates proposed to explain the failure of simple rigid Antarctic and/or Pacific plate models to match paleomagnetic data, hotspot tracks, and equatorial crossings defined by pelagic sediment deposition. We find that: 1. (1) Plate reconstruction models with either two Antarctic or two Pacific plates in the early Tertiary are distinguishable from models with single Antarctic and Pacific plates principally on the basis of faster speeds for the Kula plate and the northern Pacific, greater areas for the Kula and Farallon plates, and faster subduction at the Aleutians and along the west coast of South America for that time. 2. (2) Oceanic plates as a group have moved faster than those with continental lithosphere only since 50 m.y. ago; active subduction appears to be a sufficient condition for rapid plate motion regardless of the fractional plate area comprised of continental lithosphere. 3. (3) The absolute motion of India in the late Cretaceous was anomalously fast (15–20 cm/yr) compared to the speeds of the present plates. 4. (4) The rms velocities of a number of plates and of the lithosphere as a whole are much higher in the late Cretaceous than through most of the Cenozoic. 5. (5) The predicted apparent polar wander for North America is in fairly good agreement with paleomagnetic data, with the slight discrepancy attributable to a net contribution to the torque balance from plate boundary forces.
Environmental Contaminants in Coal Slurry Intended for Underground Injection in the State of West Virginia

AbstractWaste from coal cleaning processes includes coarse size fractions (i.e., coarse refuse) and small particles (i.e., fine refuse). The aqueous suspension of fine refuse, referred to as coal slurry, frequently contains potentially toxic substances, including hydrocarbons, heavy metals, and coal cleaning chemicals. Disposal of coal slurry using underground injection has raised environmental concerns because it may lead to contamination of groundwater and water supplies. In the present study, liquid and solid fractions of coal slurries collected from five underground injection sites and one coal preparation site in West Virginia (WV) were analyzed for a suite of 177 organic and inorganic constituents. The original data presented in this article were all collected by the WV Department of Environmental Protection, Office of Mining and Reclamation, and the U.S. Department of Interior, Office of Surface Mining, with input from the WV Department of Health and Human Resources. Several metals of health and en...
Integrated cross‐cultural business training

Addresses the theme of the internationalization of business practice at a time when research indicates that US firms are providing less training to prepare managers to be internationally effective than are firms in other industrialized countries. Describes a training programme developed for middle managers of GoldStar Electronics Corporation of Korea, a division of the Lucky GoldStar Group, by Ball State University, Indiana. Details the genesis of this inter‐departmental venture from conception to programme delivery. Gives the rationale for the 12‐day programme’s components and an account of activities through which trainees acquire the desired experiences of American culture and business practices. Highlights the overall objective as developing an understanding in participants of the process of learning about other cultures and practices. Since the rationale eschews national‐cultural specificity, argues that the programme would be equally applicable to US managers with global remits.
Compact parallel optical modified-signed-digit arithmetic-logic array processor with electron-trapping device

A compact two-step modified-signed-digit arithmetic-logic array processor is proposed. When the reference digits are programmed, both addition and subtraction can be performed by the same binary logic operations regardless of the sign of the input digits. The optical implementation and experimental demonstration with an electron-trapping device are shown. Each digit is encoded by a single pixel, and no polarization is included. Any combinational logic can be easily performed without optoelectronic and electro-optic conversions of the intermediate results. The system is compact, general purpose, simple to align, and has a high signal-to-noise ratio.
Measures of Social Functioning in Psychiatric Outcome Research

Measures of socral functioning are gaining increasing attention as important outcome criteria in evaluation of psychiatric treatment. This article reviews approaches to conceptualization and measurement of social functioning in mental health treatment outcome evaluation, and enumerates several reasons why their contribution to outcome research is valuable. The value of these measures, however, is jeopardized by lack of attention to problems posed by conceptual and psychometric issues associated with current measures, and by the social context in which the measures are embedded. Three alternative directions to take in the search for solutions are presented
Programmatic semantics for natural language interfaces

An important way of making interfaces usable by non-expert users is to enable the use of natural language input, as in natural language query interfaces to databases, or MUDs and MOOs. When the subject matter is about procedures, however, we have discovered that interfaces can take advantage of what we call Programmatic Semantics, procedural relations that can be inferred from the linguistic structure. Roughly, nouns can be interpreted as data structures; verbs are functions; adjectives are properties. Some linguistic forms imply conditionals, loops, and recursive structures.We illustrate the principles of Programmatic Semantics with a description of Metafor, a "brainstorming" editor for programs, analogous to an outlining tool for prose writing. Metafor interactively converts English sentences to partially specified program code, to be used as "scaffolding" for a more detailed program. A user study showed that Metafor is capable of capturing enough Programmatic Semantics to facilitate non-programming users and beginners' conceptualization of programming problems.
Exploring families of quantum controls for generating unitary transformations

A numerical method is presented for exploring the intertwined roles of the control-field structure and the final time T in determining the unitary evolution operator U(T, 0) for finite-level quantum control systems. The algorithm can (a) identify controls achieving a target unitary operator W at time T up to machine precision and (b) identify a continuous family of controls producing the same operator W over a continuous interval of final times. The high degree of precision is obtained, in part, by exploiting the geometry of the unitary group. In particular, geodesics of the unitary group are followed, both for tracking to a target transformation and for error management.
A computational approach to pricing a bank credit line

Abstract Using trended Brownian motion to characterize borrower cash needs over time, we are able to derive a probability density function for the time to depletion of a bank credit line as well as the likelihoods for the time to exhausting the sources of liquidity that fund the loan. Armed with these analytic results, we solve for the credit line mark-up rate and the configuration of stored liquidity that maximizes the bank’s intertemporal expected profits from the loan. The optimality conditions produce a system of integral differential equations whose solutions we then simulate over a host of scenarios.
HUSBANDS' EDUCATIONAL ATTAINMENT AND SUPPORT FOR WIVES' RETURN TO SCHOOL

This study used data collected during intensive interviews with 44 returning women students and 33 of their husbands to investigate the effects of husbands' educational attainment on their attitudes toward their wives' enrollment and on their provision of instrumental support during the first year in a university. As hypothesized, well-educated husbands held more positive attitudes toward their wives' enrollment than did less-educated husbands; however, contrary to expectations, well-educated husbands provided their wives with lower levels of instrumental support than did less-educated husbands. Less-educated husbands appear to have provided their wives with higher levels of instrumental support because they were more likely to believe that their wives' increasing educational attainment would raise the total family income.
Determining the extent of reaction by29Si NMR of abrasion-resistant hybrid sol-gel coatings based on triethoxysilane functionalized organics

Diethylenetriamine, melamine, and low molecular weight branched polyethylenimine were functionalized separately with 3-isocyanatopropyltriethoxysilane. Coatings on polycarbonate were prepared from these compounds through the sol-gel process. The extent of reaction and the relative species concentration of the trifunctional silicon atom were obtained from29Si CP-MAS NMR measurements. The sol-gel reaction was found to be limited by vitrification. A variety of silicon species was present in the vitrified coating. The extent of reaction could be increased by increasing the curing temperature, curing for longer times, and increasing the acid concentration. The extent of reaction was also found to be related to the basicity of the functionalized organic backbone.
Simulations of aerosol aggregation including long-range interactions.

Current understanding of solid aerosol particle aggregation is limited to simulation models based on diffusive and ballistic motion of the colliding particles. The role of the long-range van der Waals forces in aggregation phenomena, although important, has never been examined. In an effort to address this issue, a simulation model, based on molecular dynamics techniques, is developed. Using this model to simulate thermal collisions of single spheres with small aggregates of similar spheres, we examine the effects of retardation of the long-range van der Waals forces, particle transport, ambient temperature, and pressure on the collision rates and mass and structure distributions of the aggregated particles. The model calculations were performed at simulated temperatures of 293 and 1500 K and at simulated pressures of 760 and 3040 torr for glassy carbon primary particles in the free molecular regime with diameters of 6 nm, and in the transition regime with diameters of 30 nm. Inclusion of the long-range van der Waals forces resulted in aggregates with relatively open structures and few branches and collision rate constants that were larger than the corresponding hard sphere rate constants, whereas exclusion of the forces resulted in compact structures with more branches and smaller enhancements inmore » the rate constants. The above effects were found to be more pronounced in the free molecular regime than in the transition regime, which is consistent with the observation that the initial conditions and the interparticle forces play a more significant role in particle transport in the free molecular regime than in the transition regime. The effect of retardation of the forces is an increase in the percentage of open aggregates and the collision rate constants over that of the corresponding nonretarded case. An increase in temperature resulted in a collapse of aggregate structure and a decrease in collision rate constants corresponding to the reduced geometrical cross sections. Again, the effects were found to be more pronounced in the free molecular regime than in the transition regime. No significant difference was observed in the structure of the aggregates or in the collision rate constants with a change in pressure, indicating that the pressure effect, if any, is hidden by the much stronger effect of the long-range van der Waals forces. {copyright} {ital 1999} {ital The American Physical Society}« less
KINETIC AND THERMODYNAMIC INFORMATION DERIVED FROM ELECTROCHEMICAL MEASUREMENTS ON STATIONARY STATES

Experiments are reported on the electrochemical displacement of the nonlinear minimum bromate reaction from stationary states far from equilibrium and from equilibrium. We measure the CeIV/CeIII el...
The role of divalent cations in structure and function of murine adenosine deaminase

For murine adenosine deaminase, we have determined that a single zinc or cobalt cofactor bound in a high affinity site is required for catalytic function while metal ions bound at an additional site(s) inhibit the enzyme. A catalytically inactive apoenzyme of murine adenosine deaminase was produced by dialysis in the presence of specific zinc chelators in an acidic buffer. This represents the first production of the apoenzyme and demonstrates a rigorous method for removing the occult cofactor. Restoration to the holoenzyme is achieved with stoichiometric amounts of either Zn2+ or Co2+ yielding at least 95% of initial activity. Far UV CD and fluorescence spectra are the same for both the apo- and holoenzyme, providing evidence that removal of the cofactor does not alter secondary or tertiary structure. The substrate binding site remains functional as determined by similar quenching measured by tryptophan fluorescence of apo- or holoenzyme upon mixing with the transition state analog, deoxycoformycin. Excess levels of adenosine or N6- methyladenosine incubated with the apoenzyme prior to the addition of metal prevent restoration, suggesting that the cofactor adds through the substrate binding cleft. The cations Ca2+, Cd2+, Cr2+, Cu+, Cu2+, Mn2+, Fe2+, Fe3+, Pb2+, or Mg2+ did not restore adenosine deaminase activity to the apoenzyme. Mn2+, Cu2+, and Zn2+ were found to be competitive inhibitors of the holoenzyme with respect to substrate and Cd2+ and Co2+ were noncompetitive inhibitors. Weak inhibition (Ki > or = 1000 microM) was noted for Ca2+, Fe2+, and Fe3+.
The role of the blood in metabolism of prostaglandin E1 in the cat lung.

Abstract We found that when 15-keto-PGE1 was added to cat blood, it was converted to 13,14-dihydro-15-keto-PGE1 (dihydro-keto-PGE1) by a NADH-dependent enzyme associated with some formed element(s) in the blood. When PGE1 was injected into the pulmonary artery of blood-perfused lungs, the only metabolite detectable in the pulmonary venous blood was the dihydro-keto-PGE1. However, when the lungs were perfused with an artificial perfusate containing no blood cells, a small amount of 15-keto-PGE1 was detected in the venous effluent. Therefore it would appear that a blood-borne Δ13 reductase was partially responsible for the conversion of PGE1 to dihydro-keto-PGE1 on passage through blood-perfused cat lungs.
How Much Software Quality Investment Is Enough: A Value-Based Approach

This article draws on results from the emerging field of value-based software engineering (VBSE). VBSE aims to provide a quantitative approach to questions as how much software quality investment is enough. Based on the COCOMO II cost-estimation model and the COQUALMO quality-estimation model, quantitative risk analysis helps determine when to stop testing software and release the product. Further, we show how the model and approach can assess the relative payoff of value-based testing as compared to value-neutral testing
Discrete phase model of domain walls in ferroelectric crystals

A discrete phase model is used to simulate evolution of domain structures in ferroelectric materials. The discrete phase model balances the structural energy against local mechanical and electrical energies. Devonshire theory is used to model the structural energy while a finite element framework using scalar potential theory computes the local electric field and stress.
Learning and nonlearned neophobia enhancement both contribute to the formation of illness-induced taste aversions by deer mice (Peromyscus maniculatus bairdi)

An investigation was made of the occurrence of learned and nonlearned aversions in the acquisition of illness-induced taste aversions in mice of the genusPeromyscus. It was determined: (1) that illness following the ingestion of a novel flavor both produced aversions specific to that flavor and also enhanced neophobia directed toward novel flavors in general; (2) that the specific aversion and the enhanced neophobia appeared to be mediated by independent processes, with no indication that the enhanced neophobia was dependent upon the integrity of the specific aversion; and (3) that illness following the ingestion of familiar water produced enhanced neophobia, which did not appear to be mediated by an aversion to water. It was noted that the results were fundamentally in agreement with those previously obtained with laboratory rats, except that a demonstration of the independence between the two types of aversions has not yet been reported in those animals.
Characterization of N-succinyl metabolites of adenine and aminoimidazole carboxamide by mass spectrometry†

N6-(2-succinyl)adenosine 5′-phosphate and N-(5-amino-1-ribosyl-4-imidazole carbonyl)-L-aspartic acid ′-phosphate were prepared enzymatically using adenylosuccinate lyase (EC 4.3.2.2) isolated from human erythrocytes. N6-(2-succinyl)adenosine 5′-phosphate, N-(5-amino-1-ribosyl-4-imidazole carbonyl)-L-aspartic acid 5′-phosphate and N-(5-amino-1-ribosyl-4-imidazole carboxamide) 5′-phosphate and the nucleoside and free base analogs of these nucleotides were converted to the trimethylsilyl derivatives and characterized by mass spectrometry. The extent of the trimethylsilylation was greater for adenine substituted compounds compared with those related to aminoimidazole carboxamide. Major mass spectral fragment ions correspond to the intact base plus portions of the sugar skeleton and to electron impact-induced decomposition products of the sugar moiety. Succinyl substitution at N6 of the adenine derivatives leads to characteristic loss of CO2 SiMe3 from the molecular ion. A combination of liquid chromatographic procedures and gas chromatography mass spectrometry gave rapid and unequivocal identification of succinyladenine from human urine.
Polyacrylamide-gel electrophoresis of soybean whey proteins and trypsin inhibitors.

Abstract Polyacrylamide-gel electrophoresis with glycine buffer (pH 9.2) containing 8 m urea separated soybean whey proteins into at least 24 bands. In contrast, ultracentrifugation indicated only 2 fractions; moving-boundary electrophoresis, 8–9 components; and column chromatography, 13 or more proteins. A prominent, fast-moving band in the gel pattern appeared to be identical to crystalline soybean trypsin inhibitor. Examination of 9 commercial samples of trypsin inhibitor showed multiple bands in all; most samples separated into 6 or more bands, and one preparation resolved into at least 13 bands in the gel. An inhibitor sample isolated by column chromatography and apparently identical to crystalline inhibitor also appeared heterogeneous although it contained fewer minor bands than the commercial samples. Three other trypsin inhibitor fractions recently isolated by column chromatography likewise yielded multiple bands but distinctly different from crystalline soybean trypsin inhibitor. Polyacrylamide-gel electrophoresis appears to be a sensitive tool for examining soybean whey protein fractions and should greatly facilitate future fractionation studies on this complex protein mixture.
Measuring the Contractile Forces of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes With Arrays of Microposts

Human stem cell-derived cardiomyocytes hold promise for heart repair, disease modeling, drug screening, and for studies of developmental biology. All of these applications can be improved by assessing the contractility of cardiomyocytes at the single cell level. We have developed an in vitro platform for assessing the contractile performance of stem cell-derived cardiomyocytes that is compatible with other common endpoints such as microscopy and molecular biology. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were seeded onto elastomeric micropost arrays in order to characterize the contractile force, velocity, and power produced by these cells. We assessed contractile function by tracking the deflection of microposts beneath an individual hiPSC-CM with optical microscopy. Immunofluorescent staining of these cells was employed to assess their spread area, nucleation, and sarcomeric structure on the microposts. Following seeding of hiPSC-CMs onto microposts coated with fibronectin, laminin, and collagen IV, we found that hiPSC-CMs on laminin coatings demonstrated higher attachment, spread area, and contractile velocity than those seeded on fibronectin or collagen IV coatings. Under optimized conditions, hiPSC-CMs spread to an area of approximately 420 μm2, generated systolic forces of approximately 15 nN/cell, showed contraction and relaxation rates of 1.74 μm/s and 1.46 μm/s, respectively, and had a peak contraction power of 29 fW. Thus, elastomeric micropost arrays can be used to study the contractile strength and kinetics of hiPSC-CMs. This system should facilitate studies of hiPSC-CM maturation, disease modeling, and drug screens as well as fundamental studies of human cardiac contraction.
Magnetic Field And Field Gradient Corrections within a Nonconducting Sensor Enclosure in a Conducting Fluid---Part I: Potential Flow

Measurements of ocean-generated magnetic fields in submerged enclosures are affected by the nonconducting environment within the sensor housing. There are two physical sources for the effect: the exclusion of the electrical current from the interior of the enclosure and the perturbation of the hydrodynamic flow field produced by the enclosure. Of particular interest is the distortion of gradient-type measurements. Due to the current exclusion effect, any observed gradient dyad must be symmetric. This result is unavoidable. In order to analytically examine these effects in detail, we have considered the particular case of a spherical goemetry. Furthermore, in the present paper we neglect any vorticity associated with the perturbed velocity field (potential flow).
The continuing enigma of pyloric stenosis of infancy: a review.

Abstract:Striking features of the descriptive epidemiology of pyloric stenosis of infancy have been identified but until recently have not suggested any useful etiologic lead. The disease first received serious attention approximately 100 years ago and has since occurred throughout the Western world
Nigrostriatal dopamine actions on the D2 receptors mediate methamphetamine effects on the striatonigral substance P system.

Abstract Multiple administrations of methamphetamine to rats produced elevated concentrations of substance P-like immunoreactivity within the substantia nigra, an effect which is believed to be mediated by increases in dopaminergic activity induced by methamphetamine. The results reported here demonstrate that the effect of methamphetamine is mediated specifically by the dopamine pathway in the nigrostriatum. Thus, extensive destruction of dopamine neurons in the nigrostriatum by lesions induced by 6-hydroxydopamine or blockade of synthesis of dopamine with α -methyl- p -tyrosine prevented the increases in substance P-like immunoreactivity in the nigra, induced by methamphetamine. Similarly, the concurrent administration of the D 2 receptor antagonist, sulpiride, also prevented the effects of methamphetamine on substance P-like immunoreactivity in a dose-dependent way. In addition, multiple administrations of the D 2 agonist, RU24926, elevated, whereas the D 1 agonist, SKF38393, decreased the content of substance P-like immunoreactivity in the nigra. The effects of methamphetamine were not altered in rats with lesions induced by 5,7-dihydroxytryptamine. Thus, these findings suggest that the effect of methamphetamine on the striatonigral substance P pathway is mediated by nigrostriatal dopaminergic actions on D 2 receptors.
Liouville-type and uniqueness results for a class of elliptic equations

Abstract Liouville-type results are obtained for fourth order elliptic equations of the form Δ 2 u − q(x) g(Δu) + p(x) f(u) = 0 and Δ(q(x) g(u) Δu) + p(x) f(u) = 0 by means of two subharmonic functionals defined appropriately on their respective solutions and a Green inequality.
Uptake and fractionation of rare earth elements on hydrothermal plume particles at 9°45′N, East Pacific Rise

Abstract Particulate samples (>0.45 μm) from a neutrally buoyant hydrothermal plume at 9°45′N on the northern East Pacific Rise were collected using large volume in situ filtration and analyzed for Fe, Al, Mn, Ni, and fourteen rare earth elements (REE). The Sm/Fe ratio (a proxy for overall REE/Fe) and Nd/Er (light/heavy REE fractionation) increased moderately with decreasing particulate Fe. Chemically, the sense of these relationships matched that documented previously in the TAG plume on the Mid-Atlantic Ridge (German et al., 1990) , although particulate Fe was about 10 fold lower at 9°45′N. Spatial trends relative to the vent source, however, were opposite of expectation because slow Fe(II) oxidation and Fe(III) colloid aggregation over this interval led to increased particulate Fe (10–26 nM) with distance from source (Field and Sherrell, submitted) . After subtraction of non-plume background particle composition, plume particles at 9°45′N and TAG had indistinguishable ranges of light REE-enriched fractionation relative to ambient seawater and had very similar Sm/Fe (therefore Kd for Fe oxyhydroxides), demonstrating that plume particles in both oceans reflect to a first degree the local seawater REE composition. Within-plume REE variations at 9°45′N were investigated using a simple mixing model which accounts for the bulk Fe-Al-Mn variations in the plume using two endmembers: fresh hydrothermal oxyhydroxide precipitates and ridge-crest background particles (composed largely of locally resuspended sediment). Sm/Fe and Nd/Er plot linearly with mixing ratio (R > 0.96), implying that the observed REE trends result from mixing of these two endmembers. Extrapolation to the composition of pure hydrothermal precipitates suggests that Nd/Er is fractionated relative to seawater by a factor of 1.8 during adsorption onto fresh Fe oxyhydroxide particles. The ridge-crest background particles are 5 fold higher in Sm/Fe and Nd/Er is 2.49 relative to seawater, partly a result of enriched terrigenous component in the resuspended matter. A reinterpretation of REE at TAG reveals that positive curvature in REE vs. Fe plots, argued previously to reflect continuous REE uptake (i.e., increasing Kd; German et al., 1990 ), may result from local depletion of the dissolved REE pool by partitioning onto Fe particles at Fe > 100 nM. Similar drawdown effects could contribute to the variable degrees of curvature observed for all seawater-source particle-reactive species in plumes that are sampled at high particulate Fe concentration. In sum, REE behavior in hydrothermal plumes is more consistent with equilibrium adsorption and mixing of distinct particle types, than with kinetic uptake control. Precise measurements of REEs in modern ridge-crest metalliferous sediments could be compared to the endmember composition calculated from the plume data to evaluate long-term changes in REE of the hydrothermal component.
Gallbladder Stent Placement for Prevention of Cholecystitis in Patients Receiving Covered Metal Stent for Malignant Obstructive Jaundice: A Feasibility Study

Covered self-expanding metal stents (CSEMS) have been used for palliation of malignant distal biliary strictures. Occlusion of the cystic duct by CSEMS may be complicated by cholecystitis. This potentially could be prevented by placement of a transpapillary gallbladder stent (GBS). Between 11/2006 and 10/2007, a total of 73 patients (50 male) aged 65 ± 14 years underwent CSEMS placement for palliation of malignant obstructive jaundice. In cases where CSEMS placement caused occlusion of the cystic duct, a 7 French transpapillary pigtail gallbladder stent (GBS) was inserted to prevent cholecystitis. Of the 73 patients, 18 had a prior cholecystectomy; 34 had the CSEMS placed below the cystic duct insertion. In 19 out of the 21 patients who had a CSEMS covering the cystic duct ostium, GBS placement was attempted, which was successful in 11 individuals (58%). An attempt to access the gallbladder was complicated by wire perforation of the cystic duct in three patients; one patient requiring emergent cholecystostomy tube placement. None of the patients who underwent successful GBS placement developed cholecystitis. One GBS dislodged and was repositioned. Cholecystitis occurred in two (20%) of the ten patients without transpapillary gallbladder decompression who had a CSEMS covering the cystic duct. The ideal placement of a CSEMS is below the cystic duct insertion. Should the cystic duct ostium be occluded, placement of a GBS should be considered to minimize the risk of cholecystitis.
A GPU-accelerated face annotation system for smartphones

Face annotation makes it easy to share and manage digital photos and videos. While state-of-the-art face recognition algorithms can achieve high accuracy to support automatic face annotation, their implementations on an embedded platform cannot achieve real-time performance due to the demanding computational requirement. However, the availability of an embedded GPU in most smartphones offers the opportunity to use it as an accelerator for the face recognition task. In this demonstration, we show that, with acceleration achieved by the embedded low-power GPU, a real-time face annotation system could be realized on an existing off-the-shelf smartphone.
Determination of furosine in biomedical samples employing an improved hydrolysis and high-performance liquid chromatographic technique.

Abstract Traditionally, the most sensitive and specific determination of non-enzymatic protein glycation has involved an 18–24-h acid hydrolysis in order to generate the compound furosine, which has been detected employing reversed-phase h.p.l.c. In this study, we have reported that significant quantities of furosine can be generated with much shorter hydrolysis times employing a 90-min vapor-phase acid hydrolysis procedure. The furosine generated by vapor-phase hydrolysis is then quantitated by pulsed amperometric detection using anion-exchange high-performance liquid chromatography. Employing this method, we were able to show that furosine generated from acid hydrolysis of purified hepatic membranes in a diabetic and non-diabetic animal model agreed with traditional methods assessing total glycated protein ( i.e ., boronate affinity methods).