cssi/SciSciGPT-SciSciNet huggingface dataset:
Characterization of the human mitochondrial aconitase gene (ACO2).

Abstract We have cloned and characterized the ACO2 gene on human chromosome 22q13, which encodes the essential iron-dependent metabolic enzyme mitochondrial aconitase. We determined that the ACO2 gene comprises 18 translated exons distributed over approximately 35 kilobasepairs (kbp) of DNA. We have shown that the ACO2 mRNA is 2.7 kb in length and is expressed ubiquitously, and we can detect multiple isoforms of the ACO2 protein. As others had reported the existence of biochemically active electrophoretic variants of mitochondrial aconitase, we wished to find common ACO2 gene allozymes, functional polymorphisms that might be associated with susceptibility to human genetic diseases. We looked for ACO2 allozymes by DNA sequencing and genotyping in a population of 217 subjects, many of which had Idiopathic Parkinson's Disease (IPD). We studied patients with IPD because this movement disorder is thought to arise from defects in neuronal iron and energy metabolism, two properties with which aconitase is involved. Furthermore, reports of associations between alleles of the CYP2D6 locus (nearby on 22q13) and IPD, although inconsistent, indicated that an IPD susceptibility locus might be in linkage disequilibrium with CYP2D6 . We found three functionally silent single nucleotide polymorphisms (SNPs) present in transcribed sequences that exist in similar frequencies in IPD patients and healthy controls. These ACO2 SNPs are in linkage disequilibrium with each other, providing evidence for distinct ACO2 haplotypes. We have, as yet, not detected polymorphisms that would lead to ACO2 allozymes, nor have we observed differences in ACO2 isoform prevalence or distribution in our population of IPD patients and controls. We conclude it is unlikely that polymorphism in the ACO2 gene or post-translational modification of the enzyme predispose to IPD.
Measurements of Secondary Organic Aerosol from Oxidation of Cycloalkenes, Terpenes, and m-Xylene Using an Aerodyne Aerosol Mass Spectrometer

he Aerodyne aerosol mass spectrometer (AMS) was used to characterize physical and chemical properties of secondary organic aerosol (SOA) formed during ozonolysis of cycloalkenes and biogenic hydrocarbons and photooxidation of m-xylene. Comparison of mass and volume distributions from the AMS and differential mobility analyzers yielded estimates of “effective” density of the SOA in the range of 0.64−1.45 g/cm^3, depending on the particular system. Increased contribution of the fragment at m/z 44, CO_2^+ ion fragment of oxygenated organics, and higher “Δ” values, based on ion series analysis of the mass spectra, in nucleation experiments of cycloalkenes suggest greater contribution of more oxygenated molecules to the SOA as compared to those formed under seeded experiments. Dominant negative “Δ” values of SOA formed during ozonolysis of biogenics indicates the presence of terpene derivative structures or cyclic or unsaturated oxygenated compounds in the SOA. Evidence of acid-catalyzed heterogeneous chemistry, characterized by greater contribution of higher molecular weight fragments to the SOA and corresponding changes in “Δ” patterns, is observed in the ozonolysis of α-pinene. Mass spectra of SOA formed during photooxidation of m-xylene exhibit features consistent with the presence of furandione compounds and nitro organics. This study demonstrates that mixtures of SOA compounds produced from similar precursors result in broadly similar AMS mass spectra. Thus, fragmentation patterns observed for biogenic versus anthropogenic SOA may be useful in determining the sources of ambient SOA.
Alignment and calibration of an infrared achromatic retarder using FTIR Mueller matrix spectropolarimetry

An IR achromatic retarder was aligned and characterized using the University of Alabama in Huntsville's Fourier transform IR spectropolarimeter. The FTIR spectropolarimeter produces a full polarization description of a sample over wavelengths 3-14 micrometers . Mueller matrices were measured for different relative alignments between the complementary plates of the achromat until the retardance orientation variation was reduced to within +/- 1 degree and the retardance magnitude varied smoothly with a peak-to-valley difference of 24 degrees from 4-14 micrometers . The results presented here include the progression of retardance magnitudes and retardance orientations as the plates alignment varied as well as the final Mueller matrix and retardance components of the achromat element.
Implication of advanced donor age on the outcome of liver transplantation

Historically, age has been considered to be a relative contraindication for organ donors. The use of elderly donors for liver transplantation remains controversial due to the fear of inferior outcome. According to United Network for Organ Sharing (UNOS) data, the proportion of older donors has been increasing annually. This study describes the short- and long-term outcomes for transplantation of elderly donor livers. Three hundred and seventy-four primary liver transplantations, which had been performed at the University of Virginia Health System from 7 February 1988 to 31 December 1998, were included. Graft survival, incidence of primary non-function, and hepatic artery thrombosis (HAT) after transplantation according to the different age groups of liver donors were analyzed. Cases were analyzed by donor age (group I, n = 106: aged 5 yr younger than their age; group VI, n = 43: recipients from donors > 5 yr older than their age). Group III or VI (group of advanced donor age) and group II or V (control group) were compared by age, gender, race, body weight, height, pre-transplantation cytomegalovirus (CMV) status of the recipients donors, cause of brain death of donors, total or warm ischemic time, ABO matching, and degree of human leucocyte antigen (HLA) mismatching. No significant difference in 5 yr graft survival was found between the groups by donor age (p = 0.604) and by donor age compared with recipient age (p = 0.567). Moreover, no significant differences in the incidence of primary non-function and HAT after transplantation were found between the groups by donor age and by donor age compared with recipient age. Older donors were more likely to be women and to have antibodies to CMV, as well as to have died by cerebrovascular causes. Race, body weight, height of both recipients and donors, total or warm ischemic time of grafts, ABO matching, and degree of HLA mismatching were not significantly different between the groups. We conclude from this study that advanced donor age is not a contraindication to liver transplantation if careful assessment of donors is made on a case-by-case basis. There is a need to maintain an open mind with regard to the use of livers from older donors due to the current situation of serious organ shortages.
Image Reconstruction in Optical Tomography: Beyond the Diffusion Approximation

We review recent progress on the development of inverse scattering methods for the radiative transfer equation. Applications to the image reconstruction problem in optical tomography are described
Description and application of core cloud user roles

At IBM®, we developed a set of user roles that describe the tasks of the people who interact with any cloud based Information Technology system. The three core roles of Cloud Service Creator, Cloud Service Provider, and Cloud Service Consumer create the base for reflecting the close interaction between developers, providers, and consumers in order to achieve the optimum service flow. The development of a single role as well as the entire taxonomy of roles is guided by a framework of governing principles.Our paper will first present an overview of the user roles and basic framework. Then we will present a series of examples and best practices for interpreting and applying the roles in the design and operation of cloud computing solutions.
Maintenance of Human Hepatocyte Function In Vitro by Liver-Derived Extracellular Matrix Gels

Tissue engineering and regenerative medicine (TE&RM) approaches to treating liver disease have the potential to provide temporary support with biohybrid-liver-assist devices or long-term therapy by replacing the diseased liver with functional constructs. A rate-limiting step for TE&RM strategies has been the loss of hepatocyte-specific functions after hepatocytes are isolated from their highly specialized in vivo microenvironment and placed in in vitro culture systems. The identification of a biologic substrate that can maintain a functional hepatocyte differentiation profile during in vitro culture would advance potential TE&RM therapeutic strategies. The present study compared two different biologic substrates for their ability to support human hepatocyte function in vitro: porcine-liver-derived extracellular matrix (PLECM) or Matrigel. Because Matrigel has been shown to be the most useful matrix for static, traditional hepatocyte culture, we directly compared PLECM with Matrigel in each experiment. Albumin secretion, hepatic transport activity, and ammonia metabolism were used to determine hepatocyte function. Hepatocytes cultured between two layers of PLECM or Matrigel showed equally high levels of albumin expression and secretion, ammonia metabolism, and hepatic transporter expression and function. We conclude that like Matrigel, PLECM represents a favorable substrate for in vitro culture of human hepatocytes.
Strain relief in compositionally graded InAsxSb1−x buffer layers and InAsxSb1−x/InSb strained-layer superlattices grown by MOCVD

Abstract InAS x Sb 1- x /InSb strained-layer superlattices were grown by metalorganic chemical vapor deposition on four different types of compositionally graded InAs y Sb 1- y buffer layers. The samples were examined by X-ray diffraction and optical and transmission electron microscopy. Comparisons of the resulting surface morphology and residual strain were made between constant composition, step-graded and two types of continuously graded buffer layers. Both the buffer layer thickness and composition profile were found to affect the formation of microcracks and dislocations. Residual strain in the buffer layers examined in this study was minimized by the use of a linear variation of the composition in the graded buffer layers.
Does clopidogrel change morbidity and mortality in ICU sepsis patients

The purpose of this study was to evaluate whether patients with sepsis exposed to clopidogrel have lower mortality and fewer days on mechanical ventilation compared with patients not exposed to clopidogrel. A recent post-hoc analysis of the PLATO trial suggests that the antiplatelet agent ticagrelor provided a significant reduction in sepsis-related mortality and pulmonary adverse events compared with clopidogrel. It is unknown whether clopidogrel also provides benefit in patients with sepsis compared with no therapy. Knowing this information may help focus future research on determining the mechanism of ticagrelor's benefit.
Metaphoric cognition as social activity: Dissolving the divide between metaphor in thought and communication

Metaphoric thought is often viewed as a property of individual minds that is quite separate from people’s social, communicative actions with metaphoric language and gesture. My goal in this article is to argue that metaphoric cognition is fundamentally linked to human social activities. I defend this idea by focusing not only on metaphor use in overt communicative situations, but by suggesting ways that individual metaphoric cognition is implicitly social. Many of the experimental tasks used in psychology to demonstrate the psychological reality of conceptual metaphors reflect intricate couplings between cognitive and social processes. This argument demands a reorientation in how metaphor scholars interpret empirical findings related to conceptual metaphor theory, and more broadly aims to dissolve the long-standing theoretical divide between metaphoric cognition and metaphoric communication.
Continuum-Level Analytical Model for Solid Oxide Fuel Cells with Mixed Conducting Electrolytes

A continuum-level analytical model was developed for the performance of solid oxide fuel cells (SOFCs) with mixed conducting electrolytes. The model was derived by coupling the Nernst-Planck equation for mass transport in the bulk with the Butler-Volmer equation for mass transport across an interface and by employing defect thermodynamics for boundary values. This approach allowed the usual assumptions of reversible electrodes and linear potential gradients (across the electrolyte) to be removed, thereby resulting in boundary defect concentrations that depend on potential (SOFC operating conditions) and allowing non-ohmic responses in mixed conducting electrolytes. Using only three fitting parameters, the authors validated the model through successful fits to experimental data from SOFCs with samaria- and gadolinia-doped ceria electrolytes, which are presently the mixed conducting electrolytes of greatest interest. The fits also allowed valuable information to be extracted from the experimental data regarding the overpotentials in the SOFC. Significantly, the anode, cathode, and electrolyte overpotentials were uniquely determined, each as a function of current. Hence, it was confirmed that performance losses due to electronic leakage through ceria electrolytes is confined to low load (low current and high voltage) conditions. Finally, the model was used to show that open-circuit voltage is a function of electrolyte thickness.
Percutaneous feeding tube replacement in the ED--are confirmatory x-rays necessary?

Abstract Objective No study to date has addressed whether confirmatory x-ray after ED percutaneous feeding tube (PFT) replacement is always necessary. We hypothesized that x-ray confirmation of PFT replacement is not necessary in patients lacking both tract immaturity and trauma to the tract during dislodgement or replacement. Therefore confirmatory x-rays could safely be avoided for these patients. Methods Medical records of 113 adult PFT encounters that met inclusion criteria between December 2000 and March 2004 at an urban university hospital ED seeing approximately 50 000 adult patients per year were reviewed. Results Ninety-four patients (83%) presented secondary to dislodgement, and 19 patients (17%) presented secondary to malfunction. Forty-seven patients (42%) did not have confirmatory x-rays, and 66 (58%) had confirmatory x-rays. None of the patients discharged without a confirmatory x-ray returned with evidence of improper PFT placement. Of the 66 patients who had a confirmatory x-ray, 62 (94%) x-rays showed the feeding tube was in the correct location. In 4 patients, the x-ray showed either the PFT was not in the stomach or evidence of tract compromise. All of these patients had trauma to the tract and 3 of 4 were in immature tracts. There were only 19 patients of the total group of 113, however, who had neither trauma nor an immature tract. Conclusion Although uncommon, significant problems with PFT placement occur with the potential for catastrophic consequences. It appears that immaturity of the tract and trauma to the tract, either potential or actual, are the major risk factors for such complications.
Reliability and validity of the emergency severity index triage algorithm in a pediatric population

Study objectives: As demand for emergency services has continued to outpace available allocated resources in recent years, emergency department (ED) triage systems have faced increasing scrutiny. Longer queues for care make the use of a reliable, valid triage system imperative to patient safety. Little is known about the reliability and validity of triage systems in children. The purpose of this study is to evaluate the reliability and validity of the Emergency Severity Index (ESI) triage algorithm in a pediatric population. Methods: This 2-phase investigation used a methodologic design. In the first phase, interrater reliability was evaluated using ED triage scenarios, as well as in a prospective cohort of ED patients presenting to triage. ED triage nurses and nurse and physician investigators performed retrospective blinded triages using only the original triage note to assess reproducibility. In phase 2, validity was assessed using a retrospective analysis of observed resource use, ED length of stay, and hospitalization compared with resource utilization estimated at triage by the ESI. Results: During the validity phase, 510 patients were included in the final data analysis. Hospitalization, ED length of stay, and resource utilization were strongly associated with ESI category. In the reliability phase, weighted κ for ED nurse triage of standard scenarios ranged from 0.84 to 1.00, representing excellent agreement. Twenty ED pediatric patients were triaged simultaneously by an ED triage nurse and the nurse investigator. Weighted κ was 0.82 (95% confidence interval 0.66 to 0.98), also representing strong agreement between raters. Conclusion: When used to triage pediatric patients, the ESI triage algorithm demonstrated both reliability and validity in this tertiary care pediatric population.
Constraints on Scalar Asymmetric Dark Matter from Black Hole Formation in Neutron Stars

We consider possibly observable effects of asymmetric dark matter (ADM) in neutron stars. Since dark matter does not self-annihilate in the ADM scenario, dark matter accumulates in neutron stars, eventually reaching the Chandrasekhar limit and forming a black hole. We focus on the case of scalar ADM, where the constraints from Bose-Einstein condensation and subsequent black hole formation are most severe due to the absence of Fermi degeneracy pressure. We also note that in some portions of this constrained parameter space, nontrivial effects from Hawking radiation can modify our limits. We find that for scalar ADM with mass between 5 MeV and 13 GeV, the constraint from nearby neutron stars on the scattering cross section with neutrons ranges from ${\ensuremath{\sigma}}_{n}\ensuremath{\lesssim}{10}^{\ensuremath{-}45}\text{ }\text{ }{\mathrm{cm}}^{2}$ to ${10}^{\ensuremath{-}47}\text{ }\text{ }{\mathrm{cm}}^{2}$.
Use of dynamic theory to describe experimental results from volume holography

The general applicability of dynamic theory to the description of the recording and readout characteristics of volume (thick) hologram gratings is indicated. In dynamic theory (as opposed to static theory), the volume nature of the thick holographic grating allows the interference of an incident light beam with its own diffracted beam inside the recording medium. This effect causes the continuous recording of another grating that alters the initial one, producing a resultant grating that is not uniform through the thickness of the recording material and a grating whose writing and reading characteristics may vary dramatically depending on the recording material and the experimental conditions. A large number of diverse types of writing, reading, and angular selectivity behavior have been reported in the published literature. The dynamic theory of thick hologram writing and reading is shown to predict qualitatively all of these various types of experimental behavior.
Correctness of semantic integrity checking in database management systems

Although today’s applications are very demanding with regard to semantic integrity, few database systems provide capabilities of this type. In this paper, a definition of integrity constraint is given in terms of Relational Algebra and certain aspects are then discussed concerning transaction management in the presence of such integrity constraints. In particular, the problem of when to enforce a set of integrity constraints during the execution of a transaction is addressed. For this purpose the notion ofIntegrity Enforcement Schedule is introduced. An Integrity Enforcement Schedule represents the sequence of integrity checking actions performed during the execution of a transaction. A correctness criterion for the Integrity Enforcement Schedules is established, and a sufficient condition for the correctness is provided. Finally the notion ofMinimal Integrity Enforcement Schedule is introduced. The Minimal Integrity Enforcement Schedules are those Integrity Enforcement Schedules in which every constraint is verified ‘as soon as possible”. For this reason they are really desirable in the transaction management to avoid expensive rollingback operations. Algorithms for their construction are presented, together with the associated correctness proofs.
Nontopological magnetic monopoles and new magnetically charged black holes

The existence of nonsingular classical magnetic monopole solutions is usually understood in terms of topologically nontrivial Higgs field configurations. We show that finite energy magnetic monopole solutions also exist within a class of purely Abelian gauge theories containing charged vector mesons, even though the possibility of nontrivial topology does not even arise provided that certain relationships among the parameters of the theory are satisfied. These solutions are singular if these relationships do not hold, but even then become meaningful once the theory is coupled to gravity, for they then give rise to an interesting new class of magnetically charged black holes with hair.
World money or domestic money: Which predicts US inflation best?

Abstract In this paper I demonstrate that McKinnon and Tan's result that world money outperforms US money in explaining US inflation is sensitive to their choice of price index. When inflation is measured by the US CPI or GNP Deflator, US money outperforms world money in explaining US inflation.
Performance guarantees and applications for Xia's algorithm

Abstract Xia's algorithm consists of a reduction algorithm and a translation procedure both originally used to tackle the fixed point property for ordered sets. We present results that show that the translation procedure allows access to a much wider range of problems and results showing that the algorithm is very efficient when applied to the fixed point property in ordered sets or for order/graph isomorphism/rigidity.
Adaptive Reachability Analysis to Achieve Mission Objectives in Strongly Non-Keplerian Systems

Adaptive numerical reachability analysis is studied as a tool for coping with sensitive, strongly non-Keplerian dynamics when planning impulsive spacecraft maneuvers in pursuit of mission objectives at small-body systems. The concept of an objective reachability map is developed beginning from analytical results for the Kepler problem and is shown to become intricately structured for the environments of asteroid Itokawa and Martian satellite Phobos. An existing method for efficient map computation via heuristic refinement, originally applied to chart safety outcomes on a planar maneuver domain, is extended for application to spherical domains and two types of non-Boolean science objectives defined for target locations on the body surface: cumulative observation time and surface payload deployment accuracy. In addition to its potential as a tool for preliminary mission design and the general study of small-body dynamics, this reachability analysis method is also examined and discussed as a resource for rec...
Ab initio calculation on fullerene C-32 and its derivatives

Abstract In this paper, we studied the equilibrium geometries, the electronic structures and the binding energies of fullerene C32 as well as its hydrogenates and fluorides interactions by the SCF Hartree-Fock calculations using the latest version of GAMESS of ab initio programs. The fullerene C32 is found to have a 1A2′ closed-shell ground state in D3d symmetry or a 1EU singlet state in D3h symmetry. It is predicted to be easy to add some hydrogen or fluorine atoms to the C32 cage and to produce a series of derivatives C32H2n,C32F2n (n=l, 3, 6), in which C32H2,C32F2 (D3d), C32H6 a,C32F6 c(D3h) are more stable. We suggest that this implies that the vertex of triplet pentagons of the C32 cage is an activation site for addition.
The repellent effect of two pyrethroid insecticides on the honey bee

. . An improved model for the repellent effect of pyrethroid insecticides on insects was developed using small colonies of honey bees, Apis mellifera L., in flight cages. Conditioning to scented feeders allowed the separation of foraging bees from a single colony into paired treatment and control groups. The repellent response was characterized as a sublethal toxic effect resulting in transitory inhibition of activity. Permethrin and cypermethrin were shown to be contact repellents to honey bees; exposure was primarily to the tarsi and abdominal venter. Repellency was fully reversible within 24 h. No permanent effects on either memory function or foraging efficiency were observed following acute exposure.
Coldness triggers northward flight in remigrant monarch butterflies.

Summary Each fall, eastern North American monarch butterflies ( Danaus plexippus ) migrate from their northern range to their overwintering grounds in central Mexico [1–3]. Fall migrants are in reproductive diapause, and they use a time-compensated sun compass to navigate during the long journey south [4–6]. Eye-sensed directional cues from the daylight sky (e.g., the horizontal or azimuthal position of the sun) are integrated in the sun compass in the midbrain central complex region [7, 8]. Sun compass output is time compensated by circadian clocks in the antennae so that fall migrants can maintain a fixed flight direction south [9, 10]. In the spring, the same migrants remigrate northward to the southern United States to initiate the northern leg of the migration cycle. Here we show that spring remigrants also use an antenna-dependent time-compensated sun compass to direct their northward flight. Remarkably, fall migrants prematurely exposed to overwintering-like coldness reverse their flight orientation to the north. The temperature microenvironment at the overwintering site is essential for successful completion of the migration cycle, because without cold exposure, aged migrants continue to orient south. Our discovery that coldness triggers the northward flight direction in spring remigrants solves one of the long-standing mysteries of the monarch migration.
A 'Highly Significant' Comment

To the Editor.— A recent lead article (1983;249:3047) uses the termhighly significantseveral times in reference to the statistical difference between groups. This term, which is frequently misused in medical literature, is misleading because it implies that the difference was either important or more significant than it might otherwise have been. In fact, the termhighly significantonly means that the results were very unlikely to have been caused by chance alone. Usually, we accept a one-in-20 risk. For example, if the mean hematocrit value in a control group is different from the value for an experimental group and by appropriate statistical testing is shown to be different with aPvalue less than.05, we say that the two groups' hematocrit values are significantly different. If thePvalue had been "highly significant" at less than.001, we can only state that our conclusion is less likely to be in
The effects of aging on opioid modulation of feeding in rats

Abstract Feeding responses to naloxone and butorphanol tartrate were measured in Fisher-344 rats with ages of 2, 12, 22 and 28 months. The two younger groups were 10–100 times more sensitive than the older groups to the suppressive effects of naloxone on feeding. Additionally, the older rats were less responsive to the feeding enhancement following butorphanol injections. These results are consistent with reports of age-related changes in endogenous opioid systems.
Functional role of the 5′ terminal cloverleaf in Coxsackievirus RNA replication

Using cell-free reactions, we investigated the role of the 5' cloverleaf (5'CL) and associated C-rich sequence in Coxsackievirus B3 RNA replication. We showed that the binding of poly(C) binding protein (PCBP) to the C-rich sequence was the primary determinant of RNA stability. In addition, inhibition of negative-strand synthesis was only observed when PCBP binding to both stem-loop 'b' and the C-rich sequence was inhibited. Taken together, these findings suggest that PCBP binding to the C-rich sequence was sufficient to support RNA stability and negative-strand synthesis. Mutational analysis of the three conserved structural elements in stem-loop 'd' showed that they were required for efficient negative- and positive-strand synthesis. Finally, we showed an RNA with a 5' terminal deletion (Delta49TD RNA), which was previously isolated from persistently infected cells, replicated at low but detectable levels in these reactions. Importantly, the critical replication elements identified in this study are still present in the Delta49TD RNA.
Population Changes and Capital Accumulation: The Aging of the Baby Boom

In this paper I explore the quantitative implications for savings of population aging. In doing so, I pay particular attention to some features that have been partially over-looked in the literature. These features include the details of the population aging process, the initial conditions with respect to assets holdings, and the relation between age and household size. In order to do so, I develop recursive methods capable of dealing with overlapping generations environments where the population is stochastic.
γ-Aminobutyric AcidA Receptor Pharmacology in Rat Cerebral Cortical Synaptoneurosomes

Equilibrium binding interactions at the gamma-aminobutyric acid (GABA) and benzodiazepine recognition sites on the GABAA receptor-Cl- ionophore complex were studied using a vesicular synaptoneurosome (microsacs) preparation of rat brain in a physiological HEPES buffer similar to that applied successfully in recent GABAergic 36Cl- flux measurements. NO 328, a GABA reuptake inhibitor, was included in the binding assays to prevent the uptake of [3H]muscimol. Under these conditions, the equilibrium dissociation constant (KD) values for [3H]muscimol and [3H]diazepam bindings are 1.9 microM and 40 nM, respectively. Binding affinities for these and other GABA and benzodiazepine agonists and antagonists correlate well with the known physiological doses required to elicit functional activity. This new in vitro binding protocol coupled with 36Cl- flux studies should prove to be of value in reassessing the pharmacology of the GABAA receptor complex in a more physiological environment.
Reference materials and certified reference materials: An essential ingredient in environmental research and management

Certified Reference Materials (CRMs) are necessary and valuable tools in both research and routine chemical analysis for environmental management and in monitoring and surveillance programs. As part of the National Water Research Institute, Quality Assurance Program for environmental analysis, a series of RMs have been prepared for water analysis, and a variety of CRMs for sediment analysis. They include the world's first lake sediment CRMs for polynuclear aromatic hydrocarbons (PAHs), chlorobenzenes, polychlorinated biphenyls (PCBs) and selenium. This paper describes the research and development of the CRMs. It also briefly discusses the importance of CRMs and RMs in environmental research and management.
Carbon Dioxide Migration Pathways in Proteins

Some of the most important biological processes, such as carbon fixation, are dependent on protein-gas interactions. The motion of CO2 through the enzyme phosphoenolpyruvate carboxykinase was investigated using extensive all-atom molecular dynamics simulations. Three discrete migration pathways were located, suggesting the protein directs the movement of CO2. The chemical nature of these pathways is discussed, as are their biotechnological ramifications.
Modeling of a high throughput hot-wall reactor for selective epitaxial growth of silicon

A tubular hot-wall silicon epitaxial reactor operated in the selective deposition regime is characterized for growth rate uniformity in both the radial and longitudinal directions. The range of experimental conditions includes temperatures from 900 degrees C to 800 degrees C, pressures from 1 torr to 0.4 torr, concentrations of SiH/sub 2/Cl/sub 2/ in H/sub 2/ from 17% to 4%, and wafer diameters from 125 mm to 75 mm. The simplest possible models that accurately predict these data are formulated. The resulting simulator is used to demonstrate improvements to the existing hot-wall reactor, and to propose a design for a scaled up production-sized hot-wall reactor. >
Atypical Proarrhythmia with Dofetilide: Monomorphic VT and Exercise-Induced Torsade de Pointes

Proarrhythmia with dofetilide has most typically taken the form of torsade de pointes (TdP) and generally occurs early with therapy, such that in-hospital initiation of dofetilide with 3 days of continuous electrocardiogram monitoring is recommended. This article reports two unusual variants of ventricular proarrhythmia with dofetilide: (1) nonsustained runs of monomorphic ventricular tachycardia shortly after taking the first dose of dofetilide, confirmed by rechallenge; and (2) TdP that followed the development of isolated ventricular premature beats during an exercise test in a patient with neither excessive QT prolongation on dofetilide nor any ectopy whatsoever during in-hospital telemetric monitoring but with significant QT interval prolongation after the postectopic pause. These cases demonstrate that clinicians must be alert to the appearance of proarrhythmia with dofetilide at times other than early during drug initiation if the electrophysiological milieu is altered during nonhospital activity and/or of a pattern other than TdP.
Measurement of multipath effects in a satellite-aircraft UHF link

Preliminary results are presented which were obtained during a measurement program designed to investigate multipath effects in the propagation path at UHF frequencies from a synchronous satellite to an aircraft. Specular reflection was observed over both land and sea for grazing angles up to about 15°.
Trade-off between FPGA resource utilization and roundoff error in optimized CSD FIR digital filters

In this paper, we investigate the trade off between filter order and bits of coefficient precision in fixed-coefficient FIR digital filters utilizing canonical signed digit (CSD) coefficient representation. We demonstrate that the use of optimized CSD coefficients is often the only method for which many practical FIR filters can be prototyped on a single FPGA in today's technology. Due to finite FPGA resources, our resulting analysis of filter-length, word-length, and CSD bit optimization provides an indication of whether a desired filter performance can be obtained with a specific FPGA logic capacity. We develop a MATLAB algorithm for determining the optimum trade-off between FIR filter length and bits of precision of the coefficients in FIR digital filters. >
On the Customization of Components: A Rule-Based Approach

Realizing the quality-of-service (QoS) requirements for a software system continues to be an important and challenging issue in software engineering. A software system may need to be updated or reconfigured to provide modified QoS capabilities. These changes can occur at development time or at runtime. In component-based software engineering, software systems are built by composing components. When the QoS requirements change, there is a need to reconfigure the components. Unfortunately, many components are not designed to be reconfigurable, especially in terms of QoS capabilities. It is often labor-intensive and error-prone work to reconfigure the components, as developers need to manually check and modify the source code. Furthermore, the work requires experienced senior developers, which makes it costly. The limitations motivate the development of a new rule-based semiautomated component parameterization technique that performs code analysis to identify and adapt parameters and changes components into reconfigurable ones. Compared with a number of alternative QoS adaptation approaches, the proposed rule-based technique has advantages in terms of flexibility, extensibility, and efficiency. The adapted components support the reconfiguration of potential QoS trade-offs among time, space, quality, and so forth. The proposed rule-based technique has been successfully applied to two substantial libraries of components. The F-measure or balanced F-score results for the validation are excellent, that is, 94 percent. Index Terms-Performance measures, rule-based processing, representations.
Volatility estimation by combining stock price data and option data

Volatility modeling and analysis are traditionally based on either historical price data or option data. Finance theory shows that option prices heavily depend on the underlying stocks’ prices, thus the two kinds of data are related. This paper explores the approach that combines both stock price data and option data to perform the statistical analysis of volatility. We investigate the Black-Scholes model and an exponential GARCH model and derive the relationship among the Fisher information for volatility estimation based on stock price data alone or option data alone as well as joint volatility estimation for combining stock price data and option data. Under the Black-Scholes model an asymptotic theory for the joint estimation is established, and a simulation study is conducted to check finite sample performances of the proposed joint estimation.
The Basal Ganglia Is Necessary for Learning Spectral, but Not Temporal, Features of Birdsong

SUMMARY Executing a motor skill requires the brain to control which muscles to activate at what times. How these aspects of control—motor implementation and timing—are acquired, and whether the learning processes underlying them differ, is not well understood. To address this, we used a reinforcement learning paradigm to independently manipulate both spectral and temporal features of birdsong, a complex learned motor sequence, while recording and perturbing activity in underlying circuits. Our results uncovered a striking dissociation in how neural circuits underlie learning in the two domains. The basal ganglia was required for modifying spectral, but not temporal, structure. This functional dissociation extended to the descending motor pathway, where recordings from a premotor cortex analog nucleus reflected changes to temporal, but not spectral, structure. Our results reveal a strategy in which the nervous system employs different and largely independent circuits to learn distinct aspects of a motor skill.
Dopaminergic polymorphisms in Tourette syndrome: association with the DAT gene (SLC6A3).

Tourette syndrome (TS) is a chronic neuropsychiatric disorder characterized by involuntary motor and phonic tics. The pattern of inheritance and associated genetic abnormality has yet to be fully characterized. A dopaminergic abnormality in this disorder is supported by response to specific therapies, nuclear imaging, and postmortem studies. In this protocol, dopaminergic polymorphisms were examined for associations with TS and attention-deficit hyperactivity disorder (ADHD). Polymorphisms investigated included the dopamine transporter (DAT1 DdeI and DAT1 VNTR), dopamine receptor (D4 Upstream Repeat and D4 VNTR), dopamine converting enzyme (dopamine β-hydroxylase), and the acid phosphatase locus 1 (ACP1) gene. DNA was obtained from 266 TS individuals ± ADHD and 236 controls that were ethnicity-matched. A significant association, using a genotype-based association analysis, was identified for the TS-total and TS-only versus control groups for the DAT1 DdeI polymorphism (AG vs. AA, P = 0.004 and P = 0.01, respectively). Population structure, estimated by the genotyping of 27 informative SNP markers, identified 3 subgroups. A statistical re-evaluation of the DAT1 DdeI polymorphism following population stratification confirmed the association for the TS-total and TS-only groups, but the degree of significance was reduced (P = 0.017 and P = 0.016, respectively). This study has identified a significant association between the presence of TS and a DAT polymorphism. Since abnormalities of the dopamine transporter have been hypothesized in the pathophysiology of TS, it is possible that this could be a functional allele associated with clinical expression. © 2006 Wiley-Liss, Inc.
Primary Total Knee Arthroplasty Allogenic Transfusion Trends, Length of Stay, and Complications: Nationwide Inpatient Sample 2000–2009

Perioperative blood loss leading to blood transfusion continues to be an issue for total knee arthroplasty (TKA) patients. The US Nationwide Inpatient Sample (NIS) was used to determine annual trends in allogenic blood transfusion rates, and effects of transfusion on in-hospital mortality, length of stay (LOS), costs, discharge disposition, and complications of primary TKA patients. TKA patients between 2000 and 2009 were included (n = 4,544,999) and categorized as: (1) those who received a transfusion of allogenic blood, and (2) those who did not. Transfusion rates increased from 7.7% to 12.2%. For both transfused and not transfused groups, mortality rates and mean LOS declined, while total costs increased. Transfused patients were associated with adjusted odds ratios of in-hospital mortality (AOR 1.16; P = 0.184), 0.71 ± 0.01 days longer LOS (P < 0.0001), and incurred ($1777 ± 36; P < 0.0001) higher total costs per admission.
Is stress accumulating on the creeping section of the San Andreas fault

[1] The creeping section of the San Andreas fault (CSAF) in central California is a proposed barrier to propagation of large earthquakes. Yet, recent studies show that the creeping section is not entirely uncoupled but is accumulating slip deficit at a rate equivalent to a Mw=7.2–7.4 earthquake every 150years. A critical piece to understanding earthquake potential on the CSAF is determining whether slip deficit is occurring with stress accumulation on stick‒slip regions or without stress accumulation on stable‒sliding regions shadowed by surrounding locked areas. We use a physical model to estimate the spatial distribution of locked, stress‒accumulating areas of the fault constrained by surface creep rate measurements and GPS‒derived velocities. We find that the area of the fault accumulating stress, if ruptured every 150years, would release slip equivalent to at most a Mw=6.75 earthquake, significantly less than the Mw=7.2–7.4, 150year equivalent total slip deficit rate.
Experimental studies on masseter muscle grafts in rats: comparison of donor muscles.

Summary Experimental studies were performed in rats to explore the feasibility of using limb muscles to replace masticatory masseter muscles. The results showed that if several small fusiform muscles such as the extensor digitorum longus (EDL), soleus (SOL) and plantaris (PLT) were used for the grafting, the graft regenerated and matured fully in the masseter bed, although the weights were lower than those of contralateral control masseter muscles. If a multipennate muscle such as the gastrocnemius was used for the grafting, the graft also regenerated but later degenerated due to the lack of innervation. This is probably due to the excessive amount of connective tissue in the multipennate muscle. The connective tissue proliferates faster than the regeneration of muscle fibres and, thus, renders the innervation of muscle fibres difficult. Other factors pertinent to the possible clinical application of muscle transplantation in oral region are discussed.
Evaluation of statistical methods to estimate forest volume in a mediterranean region

The use of three estimation methods was investigated for mapping forest volume over a complex Mediterranean region (Tuscany, central Italy). The first two methods were based on the processing of satellite images, specifically a summer Landsat Thematic Mapper scene. From this scene, information about forest volume was extracted through a nonparametric approach [k-nearest neighbor (k-NN)] and by means of locally calibrated regressions. The last method considered, kriging, instead used only the spatial autocorrelation of tree volume relying on geostatistical principles. The experiments performed demonstrated that, at the original sampling density, the three methods produced nearly equivalent accuracies. This was no more the case when reducing the sampling density to various levels. Whereas, in fact, this reduction marginally affected the performances of the two remote-sensing-based methods, it dramatically degraded that of kriging. Additionally, the investigation showed how per-pixel estimates of error variance were obtainable also by k-NN and locally calibrated regression procedures, in analogy with the same property of kriging. Such estimated error variances were utilized to optimally integrate the outputs of the methods based on remotely sensed data and spatial autocorrelation. In all cases, the integrated estimation outperformed the single procedures. These results are relevant to develop an operational strategy for mapping forest attributes in complex Mediterranean areas
Adaptive software rejuvenation: degradation model and rejuvenation scheme

We present a framework of adaptive estimation and rejuvenation of software system performance in the presence of aging sources. The framework specifies that a degradation model not only describe an aging process but also enable the adaptation of model-based performance estimates to on-line measurements of data pertaining to the aging process. The adaptive estimation uses model-based a priori estimation and obtains a posteriori estimation based on the data measurements. With the adaptive estimation, the rejuvenation policy determines the time epochs for data collection and rejuvenation according to system dynamics. In the specific context of resource leaks previously assumed to lead to aging, we present a non-homogeneous Markov model to explicitly establish a connection between resource leaks and the failure rate. We demonstrate an increasing failure rate in the presence of resource leaks. 1. Introduction: the Adaptation Problem We present a framework for adaptive estimation and rejuvenation of software system performance in the presence of aging sources. We are concerned with system resource loss, in particular, memory leakage. Memory is indispensable in computer and communication systems. Memory leakage is a typical aging source for server systems due to software bugs in the client applications that use server resources. Our framework for adaptive estimation and rejuvenation consists of three integral components: a degradation model, an adaptive estimation scheme, and an adaptive rejuvenation scheduling policy. The degradation model allows adaptation of model-based performance estimates to on-line measurements of data pertaining to the aging process. The adaptive estimation scheme uses the model-based a priori estimation and obtains a posteriori estimation based on the measurements. With the adaptive estimation, the rejuvenation scheduling policy determines time epochs for data
Cytotoxic T Lymphocyte Lines Specific for Human Immunodeficiency Virus Type 1 Gag and Reverse Transcriptase Derived from a Vertically Infected Child

Cytotoxic T lymphocytes (CTL) specific for human immunodeficiency virus type 1 (HIV-1) are thought to play an important role in controlling HIV-1 infection. HIV-1-specific CTL are readily demonstrated in unstimulated peripheral blood mononuclear cells (PBMC) of HIV-infected adults but less frequently in PBMC from vertically infected children. HIV-1-specific CTL lines were derived from a long-term survivor of vertical HIV-1 infection using PBMC stimulated with a CD3-specific monoclonal antibody and interleukin-2; these lines had Gag- or reverse transcriptase (RT)-specific cytotoxicity. Cytotoxicity was restricted by major histocompatibility complex class I antigen and blocked by antibody to the T cell receptor complex. Fluorescence-activated cell sorting analysis demonstrated their phenotype to be CD3+CD4-CD8+. Unstimulated PBMC from this patient had no detectable HIV-1-specific cytotoxicity when tested against autologous HIV-1 envelope-, Gag-, or RT-expressing target cells. Thus, this child with vertically acquired HIV-1 infection likely has HIV-1-specific CTL precursors despite the absence of circulating, activated HIV-1-specific CTL.