cssi/SciSciGPT-SciSciNet huggingface dataset:
Probabilistic Resilience of DER Systems - A Simulation Assisted Optimization Approach

Energy systems resilience is becoming increasingly important as the frequency of major grid outages increases. In this work, we present a methodology to optimize a behind-tlie-meter distributed energy resource system to sustain a site's critical loads during a pre-defined outage period. With the fixed system design, we then propose an outage simulation approach to estimate the resilience potential of the DER system to sustain loads beyond the fixed outage period - a yearlong resilience performance analysis. We apply statistical analysis to assess the system's resilience performance over a broader parametric problem space on an hourly, monthly, and yearly basis. We demonstrate the impact of the pre-defined outage period on the resilience performance through a case study. Results show that the probability of surviving a random outage of a given duration changes from 20% to 95% when the outage is modeled for a weekday instead of a weekend for the given load-profile.
Variational multiscale method for fully coupled thermomechanical interface contact and debonding problems

Abstract In this study, a computational framework is proposed for thermomechanical contact and debonding problems with proper thermal resistance at the interface. Using the Variational Multiscale (VMS) framework, we present a fully coupled thermomechanical formulation with an explicit expression of the pressure at the contact interface. The formulation considers the quasi-static balance of the momentum and the transient heat transfer problem in a fully coupled fashion. At the interface, two different contact constitutive models are utilized for tension and compression. For tensile problems, in the mechanical phase, a tensile debonding model is employed, whereas in the thermal phase, the displacement-dependent model is employed. For compressive problems, in the mechanical phase, a Coulomb frictional model is employed while in the thermal phase, a pressure-dependent model is embedded. Because of the naturally derived interface stability terms that possess area- and stress-weighting, the proposed VMS formulation accommodates contact/debonding and contact/frictional sliding at the interface due to both thermal and mechanical loading without losing numerical stability. The proposed method is applied to a class of numerical test problems with discontinuity at the interfaces, and good agreement with analytical and numerical data is achieved.
Area based stratified random sampling using geospatial technology in a community-based survey

Most studies among Hispanics have focused on individual risk factors of obesity, with less attention on interpersonal, community and environmental determinants. Conducting community based surveys to study these determinants must ensure representativeness of disparate populations. We describe the use of a novel Geographic Information System (GIS)-based population based sampling to minimize selection bias in a rural community based study. We conducted a community based survey to collect and examine social determinants of health and their association with obesity prevalence among a sample of Hispanics and non-Hispanic whites living in a rural community in the Southeastern United States. To ensure a balanced sample of both ethnic groups, we designed an area stratified random sampling procedure involving three stages: (1) division of the sampling area into non-overlapping strata based on Hispanic household proportion using GIS software; (2) random selection of the designated number of Census blocks from each stratum; and (3) random selection of the designated number of housing units (i.e., survey participants) from each Census block. The proposed sample included 109 Hispanic and 107 non-Hispanic participants to be recruited from 44 Census blocks. The final sample included 106 Hispanic and 111 non-Hispanic participants. The proportion of Hispanic surveys completed per strata matched our proposed distribution: 7% for strata 1, 30% for strata 2, 58% for strata 3 and 83% for strata 4. Utilizing a standardized area based randomized sampling approach allowed us to successfully recruit an ethnically balanced sample while conducting door to door surveys in a rural, community based study. The integration of area based randomized sampling using tools such as GIS in future community-based research should be considered, particularly when trying to reach disparate populations.
The additive impact of the distal ureteral diameter ratio in predicting early breakthrough urinary tract infections in children with vesicoureteral reflux.

Summary Introduction Many factors influence patient and provider decisions to surgically correct vesicoureteral reflux (VUR), including risk of breakthrough febrile urinary tract infections and likelihood of spontaneous resolution. Ureteral diameter ratio has been shown in several studies to be more predictive than reflux grade with regard to breakthrough urinary tract infection (UTI). We developed and investigated the accuracy of a computational model for predicating febrile breakthrough urinary tract infection within 13 months of starting prophylactic antibiotics in children with VUR. Objective The aim of this study was to validate a model for evaluating the impact of distal ureteral diameter ratio (UDR) in predicting early breakthrough urinary tract infections in children with VUR. Study design Following a retrospective review, we recorded patient demographics, presenting symptoms, VUR grade, laterality, VUR during filling or voiding, initial bladder volume at the onset of VUR, ureteral duplication, voiding dysfunction, distal ureteral diameter ratio, and number of UTIs prior to VUR diagnosis. NeUROn++, a set of C++ programs, was used to model each data set using logistic regression and neural networks with different architectures. Results After exclusions, 136 children (93 girls and 43 boys) diagnosed with primary VUR had detailed VCUG and UDR data available. Fourteen children (10.3%) experienced breakthrough febrile UTI events within 13 months of VUR diagnosis. There was a significant association with UDR and breakthrough UTI (p = 0.008). Various computational prediction models for the outcome of breakthrough UTI were developed and evaluated. The computational model that fit best was a model using all variables with an ROC of 0.802. Discussion and conclusions Clinicians and parents often opt for intervention based on likelihood of spontaneous resolution of VUR as well as clinical course, thereby placing an emphasis on the ability to predict likelihood of breakthrough UTI infections. Our statistical analysis and prediction models further confirm UDR as an important variable predictive of breakthrough UTIs within the first 13 months of beginning prophylactic antibiotics. Furthermore, we developed a neural network model incorporating UDR and grade with an ability to yield the greatest accuracy of any breakthrough UTI predictive calculator to date at 80%.
Determining the Activity Series with the Fewest Experiments Using Sorting Algorithms

Determining the activity series of a collection of elements is a classic pedagogical experiment, in which pairs of elements are reacted to determine the relative rank ordering of their reactivity. Determining the optimal sequence of pairwise experiments that minimizes the total number of experiments corresponds to well-known comparison sorting algorithms in computer science. We describe relevant algorithms (insertion sort, binary insertion sort, merge sort, and merge insertion sort) and their application to the activity series problem and discuss ways that this connection can contribute to the introductory chemistry and computer science curricula. In addition to pedagogical interest, this illustrates a simple form of artificial intelligence for chemical experiment planning.
Polymer informatics with multi-task learning

Summary Modern data-driven tools are transforming application-specific polymer development cycles. Surrogate models that can be trained to predict properties of polymers are becoming commonplace. Nevertheless, these models do not utilize the full breadth of the knowledge available in datasets, which are oftentimes sparse; inherent correlations between different property datasets are disregarded. Here, we demonstrate the potency of multi-task learning approaches that exploit such inherent correlations effectively. Data pertaining to 36 different properties of over 13,000 polymers are supplied to deep-learning multi-task architectures. Compared to conventional single-task learning models, the multi-task approach is accurate, efficient, scalable, and amenable to transfer learning as more data on the same or different properties become available. Moreover, these models are interpretable. Chemical rules, that explain how certain features control trends in property values, emerge from the present work, paving the way for the rational design of application specific polymers meeting desired property or performance objectives.
Communicating results of pRCTs to the medical community

Abstract The purpose of pragmatic clinical trials (PCTs) is to produce results that directly address the practical questions raised by clinicians, patients, health systems, payers and other decision-makers. It is therefore fundamental that when PCTs are completed, their results should be shared effectively with clinicians and others. The simple act of releasing new information through traditional channels such as publications and continuing medical education, even using sophisticated methods, is rarely sufficient to lead to uptake of research findings and change in clinical practice; dissemination and implementation efforts require dedicated, well-informed, and inclusive strategies. In this chapter, we consider potential approaches for disseminating research evidence to clinicians and for implementing research into practice. We discuss barriers to uptake from the point of view of the Patient-Centered Outcomes Research Institute (PCORI), a funder with a strong commitment to the dissemination and implementation of evidence. Finally, we provide examples of dissemination approaches that target clinicians, and of implementation approaches designed to integrate new evidence into care delivery.
Reproduction is affected by individual breeding experience but not pair longevity in a socially monogamous bird

In socially monogamous animals, maintaining stable mating pairs across years has been hypothesized to result in increased reproductive success. However, previous individual breeding experience may independently affect reproductive success, regardless of pair stability. We examined associations between pair composition based on previous breeding experience, pair longevity, and reproduction in socially monogamous mountain chickadees, Poecile gambeli, in the Sierra Nevada. There were no significant differences in any reproductive parameters between pairs of experienced breeders that had bred together in previous years and those that were newly formed. Pairs in which both partners were experienced had heavier nestlings than both first-year breeders and mixed experienced–inexperienced pairs. Experienced females started laying eggs earlier and laid larger clutches regardless of their social mate’s previous breeding experience. As all experienced birds were older than inexperienced breeders, it remains possible that observed differences between these groups were due to age rather than breeding experience. Overall, our data did not support the hypothesis that pair longevity drives reproductive investment. We showed that pair longevity in birds with previous experience had no significant association with any reproductive parameters. Instead, we detected that individual-level characteristics related to either previous breeding experience or age (first-year breeders vs. older, experienced breeders) were associated with earlier breeding, larger clutch size, and heavier nestlings. While it remains unclear whether age, breeding experience, or both influence the observed differences in reproductive investment, our results do suggest that pair longevity may not be a critical determinant of reproductive investment in a relatively short-lived, socially monogamous species.
Transitioning to the Journal of Inter-Organizational Relationships

Welcome to the transitional issue of the Journal of Inter-Organizational Relationships. JIOR has emerged from the Journal of Marketing Channels with a new focus, while not forgetting JMC’s legacy o...
Endocannabinoid-Dopamine Interactions Shape Ethologically Relevant Behavior through Computation of Conditioned Stimuli

Endocannabinoids are theorized to modulate cue-motivated behavior by amplifying dopamine release within the mesolimbic dopamine system. Here, we summarize the neurochemical results that revealed how endocannabinoids, particularly 2-arachidonoylglycerol within the ventral tegmental area, augment cue-evoked dopamine release events into the nucleus accumbens while concurrently facilitating cue-motivated behavior. Data are initially described within the context of the classical role attributed to the mesolimbic system—promoting reward seeking. We then expand our discussion beyond simple reward-directed behaviors by discussing a potential role for endocannabinoid-mesolimbic dopamine interactions in: switching an animal’s motivation from feeding to foraging behavior when reward availability is temporally delayed, facilitating the extinction of fear memories by amplifying dopaminergic updates of the association between aversive stimuli and their predictors to the fear network, and promoting the avoidance of harmful stimuli through newly discovered negative reinforcement mechanisms.
La autoevaluación en edades tempranas, mecanismo para potenciar aprendizajes

En los ultimos tempos la educacion infantil ha adquirido especial relevancia en el marco de las politicas educacionales de los paises latinoamericanos y en especial de Chile (CONTRERAS, HERRERA; LEYTON, 2007; DIEZ, 2011; DUSSAILLANT, 2009; TOKMAN, 2010). La investigacion centra su atencion en la calidad educativa y, en particular, en los procesos autoevaluativos que demuestran los ninos de edades tempranas. Desde una perspectiva paradigmatica cuantitativa, apoyada de reportes cualitativos, el estudio presenta la capacidad explicativa de las variables metacognicion, autorregulacion, autoeficacia, lenguaje y autoconcepto, respecto del desarrollo de la autoevaluacion y su vinculacion con mejores niveles de logros en parvulos de cinco a seis anos. Los hallazgos muestran que la autoevaluacion es una dimension que muestra diversos niveles de expresion en el grupo investigado, fuertemente influenciada por las profesionales del area, tal como se aprecia en los discursos infantiles. Ademas, las variables analizadas presentan diferentes grados de contribucion a la explicacion de la autoevaluacion en el grupo estudiado.
Judging State-Sponsored Violence, Imagining Political Change

1. Introduction: transitional justice and the 'gray zone' 2. Human rights legalism and the legacy of Nuremberg 3. A different kind of justice: South Africa's alternative to legalism 4. Political judgment and transitional justice: actors and spectators 5. Rethinking restorative justice 6. Remembering resistance 7. Conclusion: the shadows of the past.
Sulfhydryl reactivity of human erythrocyte superoxide dismutase. On the origin of the unusual spectral properties of the protein when prepared by a procedure utilizing chloroform and ethanol for the precipitation of hemoglobin.

Abstract 1. 1.|During purification of human superoxide dismutase by the McCord-Fridovich procedure (McCord, J.M. and Fridovich, I. (1969) J. Biol. Chem. 244, 6049–6055) the ‘extra’ sulfhydryl groups react with a variety of sulfur containing compounds including zero-valent sulfur to yield several dismutase fractions containing excess sulfur atoms and having a unique absorption band in the region of 325 nm. This is shown to be artefact of the purification procedure. 2. 2.|Cysteine trisulfide and glutathione polysulfide were found to react with native human superoxide dismutase to yield derivatives having no reactive sulfhydryl groups and possessing spectral properties similar to the various fractions obtainable from the above purification procedure. A structure of the type protein-CH2-S-(S)nR is proposed to account for the results. The value of n is variable, and the additional sulfur reactive toward thiol reagents is thought to be due to persulfides (R = H). The 325 nm band is probably due to a n → σ ss ∗ transition associated with a strained S-S bound.
CD4+ T Cells Provide Intermolecular Help To Generate Robust Antibody Responses in Vaccinia Virus–Vaccinated Humans

Immunization with vaccinia virus elicits a protective Ab response that is almost completely CD4 + T cell dependent. A recent study in a rodent model observed a deterministic linkage between Ab and CD4 + T cell responses to particular vaccinia virus proteins suggesting that CD4 + T cell help is preferentially provided to B cells with the same protein specificity (Sette et al. 2008. Immunity 28: 847–858). However, a causal linkage between Ab and CD4 + T cell responses to vaccinia or any other large pathogen in humans has yet to be done. In this study, we measured the Ab and CD4 + T cell responses against four vaccinia viral proteins (A27L, A33R, B5R, and L1R) known to be strongly targeted by humoral and cellular responses induced by vaccinia virus vaccination in 90 recently vaccinated and 7 long-term vaccinia-immunized human donors. Our data indicate that there is no direct linkage between Ab and CD4 + T cell responses against each individual protein in both short-term and long-term immunized donors. Together with the observation that the presence of immune responses to these four proteins is linked together within donors, our data suggest that in vaccinia-immunized humans, individual viral proteins are not the primary recognition unit of CD4 + T cell help for B cells. Therefore, we have for the first time, to our knowledge, shown evidence that CD4 + T cells provide intermolecular (also known as noncognate or heterotypic) help to generate robust Ab responses against four vaccinia viral proteins in humans.
Automatic SQL tuning in oracle 10g

SQL tuning is a very critical aspect of database performance tuning. It is an inherently complex activity requiring a high level of expertise in several domains: query optimization, to improve the execution plan selected by the query optimizer; access design, to identify missing access structures; and SQL design, to restructure and simplify the text of a badly written SQL statement. Furthermore, SQL tuning is a time consuming task due to the large volume and evolving nature of the SQL workload and its underlying data. In this paper we present the new Automatic SQL Tuning feature of Oracle 10g. This technology is implemented as a core enhancement of the Oracle query optimizer and offers a comprehensive solution to the SQL tuning challenges mentioned above. Automatic SQL Tuning introduces the concept of SQL profiling to transparently improve execution plans. It also generates SQL tuning recommendations by performing cost-based access path and SQL structure "what-if" analyses. This feature is exposed to the user through both graphical and command line interfaces. The Automatic SQL Tuning is an integral part of the Oracle's framework for self-managing databases. The superiority of this new technology is demonstrated by comparing the results of Automatic SQL Tuning to manual tuning using a real customer workload.
Silicon hetero-interface photodetector

We propose and demonstrate a novel avalanche photodetector that uses separate InGaAs absorption and Si multiplication regions fabricated by wafer fusion. Directly integrating InGaAs and silicon layers in an avalanche photodetector combines the high long-wavelength absorption capabilities of InGaAs and the avalanche multiplication properties of Si. The large ratio of electron and hole ionization coefficients of silicon results in lower noise and a higher gain bandwidth product than achievable using III-V semiconductors in avalanche regions.
Cyclic AMP-dependent stimulation of basolateral K(+)conductance in the rabbit conjunctival epithelium.

The regulation of Na(+)transport by cAMP in freshly isolated rabbit conjunctival epithelium, a tissue exhibiting both Cl(-)secretion and Na(+)absorption, was examined. Bulbar-palpebral segments of conjunctiva were mounted between Ussing-type hemichambers under short-circuit conditions in Cl(-)free media. In this situation, the short-circuit current (I(sc)) measures an amiloride-resistant Na(+)absorptive process in the apical-to-basolateral direction. Apical additions (each at 10 microm) of cAMP-elevating compounds, forskolin, rolipram, IBMX and epinephrine all stimulated the Na(+)-dependent I(sc)by approximately 3.5-4.5 microA cm(-2)(minimal 40% increase) and reduced transepithelial resistance (R(t)) by at least 7% (P<0.05). Pre-exposure (1 hr) to the protein kinase A (PKA) inhibitor H-89 (10 microm), which in itself inhibited the I(sc)by 0. 5 microA cm(-2), attenuated the I(sc)responses of the cAMP-elevating agents (P< 0.05, unpaired data). In reverse, H-89 promptly decreased the I(sc)by 1.5-2.5 microA cm(-2)and increased R(t)by 5% (P<0.05) in tissues pre-stimulated with either forskolin or an epinephrine plus IBMX combination. Additions of epinephrine or rolipram to apically permeabilized preparations using amphotericin B, increased the I(sc)by 12 and 22% respectively over baseline and reduced R(t)by 6% (P<0.05). Similarly, in the presence of a transepithelial K(+)gradient (apical to basolateral) and amphotericin B, cAMP elevation stimulated K diffusion across the preparation by at least 1.8 microA cm(-2)and decreased the R(t)by 4% (P<0.05), changes that were reversed by subsequent H-89 addition. Under Cl(-)rich conditions, pretreatment with 5 m m Ba(2+)reduced the basal I(sc)by 59% and blocked the cAMP-induced I(sc)stimulations typically seen in the presence of the anion. The results provide evidence for a PKA-regulated, Ba(2+)-inhibitable (voltage insensitive) basolateral K(+)conductance in rabbit conjunctival epithelial cells. The action of Cl(-)secretogogues acting via cAMP on basolateral K(+)channel activity indicates that endogenous levels of cAMP may play a role in the regulation of Cl(-)secretion and Na(+)absorption in the conjunctiva.
Inhibitor-1 interaction domain that mediates the inhibition of protein phosphatase-1.

Inhibitor-1 (I-1), a cyclic AMP-regulated phosphoprotein, inhibits protein phosphatase-1 (PP1) activity in response to hormones. The molecular mechanism for PP1 inhibition by I-1 remains unknown. Mutation of nine acidic residues lining a proposed I-1-binding channel in rabbit PP1α yielded one mutant (E256A) slightly impaired in its inhibition by I-1, with the IC50 increased by 3-fold, and one mutant (E275R) located in the β12–β13 loop that showed 4-fold enhanced inhibition by I-1. Substituting Tyr-272, a proposed binding site for the toxins okadaic acid and microcystin-LR, in the β12–β13 loop with Trp, Phe, Asp, Arg, or Ala impaired PP1α inhibition by I-1 by 8–10-fold. Chemical mutagenesis of the Saccharomyces cerevisiae PP1 gene (GLC7) yielded 20 point mutations in the PP1 coding region. Two-hybrid analyses and biochemical assays of these yeast enzymes identified four additional residues in the β12–β13 loop that were required for PP1 binding and inhibition by I-1. Ten-fold higher concentrations of I-1 were required to inhibit these mutants. Finally, deletion of the β12–β13 loop from PP1α maintained full enzyme activity, but attenuated inhibition by I-1 by >100-fold. These data identified the β12–β13 loop in the PP1 catalytic subunit as a domain that mediates binding and enzyme inhibition by I-1.
Numerical examination of acousto-optic Bragg interactions for profiled lightwaves using a transfer function formalism

Classically, acousto-optic (AO) interactions comprise scattering of photons by energetic phonons into higher and lower orders. Standard weak interaction theory describes diffraction in the Bragg regime as the propagation of a uniform plane wave of light through a uniform plane wave of sound, resulting in the well-known first- and zeroth-order diffraction. Our preliminary investigation of the nature of wave diffraction and photon scattering from a Bragg cell under intensity feedback with profiled light beams indicates that the diffracted (upshifted photon) light continues to maintain the expected (uniform plane wave) behavior versus the optical phase shift in the cell within a small range of the Q-parameter, and at larger Qs, begins to deviate. Additionally, we observe the asymptotic axial shift of the beam center as predicted by the transfer function formalism.
Input Tolerance Considerations for Multithreshold Threshold Elements

This paper deals with input tolerance considerations of a multithreshold threshold element. The concept of a multilevel minus-plus-one model[9] of a threshold element is introduced. It is shown that the multilevel minus-plus-one model is equivalent to the zero-one model[9] of a multithreshold element. The equivalence is established through a set of defining equations similar to that of a single threshold threshold element. For a nonlinearly separable Boolean function, more than one multithreshold weight threshold vector may exist for its realization, even though the number of thresholds and the sum of the absolute magnitude of all the input weights are the same; i.e., ?n i=1 |w i |. From reliability considerations, the optimal synthesis of the multithreshold threshold elements is shown to depend on the magnitudes of max (|T 1 |, |T k |) in addition to the minimum number of thresholds needed to realize the Boolean function and the min ?n i=1 |w i |. An example is given for illustrative purposes of choosing an optimal realization. For a given margin of operation with the error model assumed, it is shown that one need only work from the normalized set of inequalities. The solution with margins specified is obtained from the optimal solutions of the normalized system of inequalities.
Crust 5.1‐based inference of the Earth's dynamic surface topography: geodynamic implications

SUMMARY We employ the recently published Crust 5.1 model of global crustal structure (Mooney et al. 1998) to estimate the topographic contributions of isostatically compensated crustal loads and, in turn, infer a long-wavelength field for Earth’s dynamic surface topography. Our inference of dynamic surface topography is characterized by peak-to-peak variations of the order of 4 km. We argue that the square root of age variation of the oceanic bathymetry has a dynamic origin. Remarkably, continental regions are the site of deep (approximately 1.5 km) dynamic surface topography depressions. The power spectrum of the field is dominated by spherical harmonic degrees l=1, 4 and 5, suggesting the importance of continent‐ocean differences, rather than deep lower mantle heterogeneity, to its origin. We model the Crust 5.1-based inference of dynamic surface topography within the context of seismic tomography-based internal loading theories. We compute the depth dependences of dynamic surface topography response functions for various viscosity profiles that we consider in our analyses. Our best descriptions of the Crust 5.1-based inference achieve total variance reductions of the order of 70 per cent in the spherical harmonic degree range l=1‐8. These are obtained for wholemantle circulation models that preclude lower mantle heterogeneity from maintaining significant vertical stresses on the outer surface. These models are characterized by a significant increase in viscosity across the depth of the 660 km seismic discontinuity, by a factor of at least 50 relative to the average viscosity of the upper mantle. We also consider results of a layered circulation model but, in this case, we are unable to reconcile constraints provided by large-scale superswell topography. We propose that the antipodal Pacific and African superswells are dynamically maintained by positively buoyant lower mantle superplumes imparting on the outer surface a large-scale, low-amplitude, predominantly degree 2 pattern of vertical stresses. Finally, we note that the Crust 5.1based inference of dynamic surface topography provides useful geodynamic constraints on the nature of deep subcontinental structure: optimal descriptions of the data require deep subcontinental keels composed of anomalously dense material.
Binary fate decisions in differentiating neurons.

Neural cell fate programs must generate an enormous number of neurons with distinct adult functions. The decision to choose one neuronal subtype from two alternatives--a binary fate decision--is one way to diversify neuronal subtypes during nervous system development. Recent progress has been made in describing the genetic programs that define late-stage neuronal identity. Here, we review mechanisms that control how such fate decisions generate two different post-mitotic, terminally differentiated neuronal subtypes. We survey examples from C. elegans and Drosophila that demonstrate different modes of binary neuronal fate specification that depend on cell division, lineage, stochastic gene expression, or extracellular signals. Comparison of these strategies reveals that, although organisms use diverse approaches to generate neural diversity, some common themes do exist.
MICROSCOPIC MODELING OF VEHICLE START EMISSIONS

A microscopic framework for estimating instantaneous vehicle start emissions for light-duty vehicles and trucks is developed. The framework assumes a linear decay in instantaneous start emissions over a 200-s time horizon. The initial vehicle start emissions rate is computed by using the soak time function of the U.S. Environmental Protection Agency's MOBILE6 model, assuming a 200-s decay time interval. The use of the MOBILE6 soak time function ensures that the microscopic procedures that are developed produce start emissions that are consistent with the MOBILE6 model. The validity of the framework was demonstrated using independent trips that involved cold-start and hot-start impacts with vehicle emissions estimated to within 10% of the test in-laboratory measurements.
Solvent Dependent Changes in the Proton NMR Spectra of 2′-Deoxyadenosine and Its Derivatives

Abstract Intramolecular hydrogen bonding in four purine-2′-deoxyribosides containing free sugar hydroxyls has been observed in CDCl3. This bond results in the appearance of a double doublet for H-1′ of the C-6 substituted β-anomers. On increasing the solvent polarity, as in DMSO-d6, the signal appears as triplet, which is typical of previously reported NMR spectra of β-anomers in D2O and DMSO-d6. Solvent polarity, therefore plays a significant role in determining the splitting patterns of the anomeric proton in these compounds.
Mechanism of active K+ secretion by flounder urinary bladder.

We investigated the mechanism of active K+ transport by the urinary bladder of the winter flounder by measuring transepithelial properties in Ussing Chambers and by determining the cellular electrical potential profile using conventional microelectrodes. In the absence of transmural electrochemical potential gradients isolated bladders can exhibit a serosa-to-mucosa short circuit which is due entirely to net K+ secretion. The properties of transcellular K+ movement can be adequately described by a model which provides for active K+ uptake across the basolateral membrane via an electrogenic Na/K ATPase and K+ exit from the cell across the apical membrane down an electrochemical potential gradient via K+ channels which are blocked by mucosal barium. The conductance of the apical membranes of the transporting cells appears to be due almost solely to K+ while that of the basolateral membrane may be due largely to Cl−.
Edge Fracture Prediction of Traditional and Advanced Trimming Processes for AA6111-T4 Sheets

This work examines the traditional and advanced trimming of AA6111-T4 aluminum sheets with finite element simulations. The Rice-Tracy damage model is used for the simulation with damage parameters estimated from experimental observation of grain aspect ratio near the fracture surface of trimmed parts. Fine meshes at the shearing zone, adaptive meshing, and adaptive contact techniques are used to accurately capture the contact interactions between the sharp corner of the trimming tools and the blank to be trimmed. To the knowledge of the authors, these are the first trimming simulations that can predict the effects of shearing clearance on burr heights with quantitative accuracy for AA6111-T4 aluminum sheets. In addition, the models have also accurately reproduced the crack initiation site as well as burr and sliver formation mechanisms observed experimentally.
Optimum Steeping Process for Wet Milling of Sorghum

ABSTRACT Pioneer 8500, a red hard sorghum hybrid, was steeped batchwise using three steeping solutions at 50°C: SO2 solution; SO2 solution containing 1.25% (w/w) of a commercial multiple-enzyme preparation (Novo SP249); and SO2 solution with the addition of 0.5% (w/w) lactic acid. Novo SP249 contained pectolytic, cellulolytic, hemicellulolytic, and proteolytic activities and small amounts of saccharolytic activities. Three SO2 concentrations (0.1, 0.2, and 0.3% w/v) prepared by dissolving sodium bisulfite in distilled water and three steeping times (24, 36, and 48 hr) were used. Incorporation of multiple enzymes into the SO2 resulted in an increase in starch yield with reduced protein content compared with the SO2 solution alone. The best wet-milling performance for sorghum resulted from the SO2 solution containing 0.5% lactic acid; it produced the whitest starch with the highest yield and the lowest protein content. Both higher SO2 concentration of the steeping solution and longer steeping time led to hi...
A live attenuated chimeric recombinant parainfluenza virus (PIV) encoding the internal proteins of PIV type 3 and the surface glycoproteins of PIV type 1 induces complete resistance to PIV1 challenge and partial resistance to PIV3 challenge.

Abstract The recovery of wild type and attenuated human parainfluenza type 3 (PIV3) recombinant viruses has made possible a new strategy to rapidly generate a live-attenuated vaccine virus for PIV1. We previously replaced the coding sequences for the hemagglutinin-neuraminidase (HN) and fusion (F) proteins of PIV3 with those of PIV1 in the PIV3 antigenomic cDNA. This was used to recover a fully-viable, recombinant chimeric PIV3-PIV1 virus, termed rPIV3-1, which bears the major protective antigens of PIV1 and is wild type-like with regard to growth in cell culture and in hamsters [Tao T, Durbin AP, Whitehead SS, Davoodi F, Collins PL, Murphy BR. Recovery of a fully viable chimeric human parainfluenza virus (PIV) type 3 in which the hemagglutinin-neuraminidase and fusion glycoprotein have been replaced by those of PIV type 1. J Virol 1998;72:2955–2961]. Here we report the recovery of a derivative of rPIV3-1 carrying the three temperature-sensitive and attenuating amino acid coding changes found in the L gene of the live-attenuated cp45 PIV3 candidate vaccine virus. This virus, termed rPIV3-1.cp45L, is temperature-sensitive with a shut-off temperature of 38°C, which is similar to that of the recombinant rPIV3cp45L, which possesses the same three mutations. rPIV3-1.cp45L is attenuated in the respiratory tract of hamsters to the same extent as rPIV3cp45L. Infection of hamsters with rPIV3-1.cp45L generated a moderate level of hemagglutination-inhibiting antibodies against wild type PIV1 and induced complete resistance to challenge with wild type PIV1. This demonstrates that this novel attenuated chimeric virus is capable of inducing a highly effective immune response against PIV1. It confirms previous observations that the surface glycoproteins of parainfluenza viruses are sufficient to induce a high level of resistance to homologous virus challenge. Unexpectedly, infection with recombinant chimeric virus rPIV3-1.cp45L or rPIV3-1, each bearing the surface glycoprotein genes of PIV1 and the internal genes of PIV3, also induced a moderate level of resistance to replication of wild type PIV3 challenge virus. This indicates that the internal genes of PIV3 can independently induce protective immunity against PIV3 in rodents, albeit a lower level of resistance than that induced by the surface glycoproteins. Thus, a reverse genetics system for PIV3 has been used successfully to produce a live attenuated PIV1 vaccine candidate that is attenuated and protective in experimental infection in hamsters.
Fluxes and transformations of nitrogen in a high-elevation catchment, Sierra Nevada

The fluxes and transformations of nitrogen (N) were investigated from 1985 through 1987 at the Emerald Lake watershed (ELW), a 120 ha high-elevation catchment located in the southern Sierra Nevada, California, USA. Up to 90% of annual wet deposition of N was stored in the seasonal snowpack; NO 3 − and NH 4 + were released from storage in the form of an ionic pulse, where the first fraction of meltwater draining from the snowpack had concentrations of NO 3 − and NH 4 + as high as 28 μeq L−1 compared to bulk concentrations of <5 μeq L−1 in the snowpack. The soil reservoir of organic N (81 keq ha−1) was about ten times the N storage in litter and biomass (12 keq ha−1). Assimilation of N by vegetation was balanced by the release of N from soil mineralization, nitrification, and litter decay. Mineralization and nitrification processes produced 1.1 keq ha−1 yr−1 of inorganic N, about 3 1/2 times the loading of N from wet and dry deposition. Less than 1% of the NH 4 + in wet and dry deposition was exported from the basin as NH 4 + . Biological assimilation was primarily responsible for retention of NH 4 + in the basin, releasing one mode of H+ for every mole of NH 4 + retained and neutralizing about 25% of the annual acid neutralizing capacity produced by mineral weathering in the basin. Nitrate concentrations in stream waters reached an annual peak during the first part of snowmelt runoff, with maximum concentrations in stream water of 20 μeq L−1, more than 4 times the volume-weighted mean annual concentrations of NO 3 − in wet deposition. This annual peak in stream water NO 3 − was consistent with the release of NO 3 − from the snowpack in the form of an ionic pulse; however soil processes occurring underneath the winter snowpack were another potential source of this NO 3 − . Concentrations of stream water NO 3 − during the summer growing season were always near or below detection limits (0.5 μeq L−1).
Unitarity and the scale of fermion mass generation

We study the upper bound on the scale of fermion mass generation in a two-Higgs-doublet model. If the model is weakly-coupled, the scale of fermion mass generation is much less than the Appelquist-Chanowitz unitarity bound. However, if we allow some dimensionless Higgs self-couplings to become large, the Appelquist-Chanowitz unitarity bound can be saturated. The unitarity bound on the scale of top-quark mass generation is about 3 TeV, which may be within the reach of future colliders.
Studying Radiation Damage in Structural Materials by Using Ion Accelerators

Radiation damage in structural materials is of major concern and a limiting factor for a wide range of engineering and scientific applications, including nuclear power production, medical applications, or components for scientific radiation sources. The usefulness of these applications is largely limited by the damage a material can sustain in the extreme environments of radiation, temperature, stress, and fatigue, over long periods of time. Although a wide range of materials has been extensively studied in nuclear reactors and neutron spallation sources since the beginning of the nuclear age, ion beam irradiations using particle accelerators are a more cost-effective alternative to study radiation damage in materials in a rather short period of time, allowing researchers to gain fundamental insights into the damage processes and to estimate the property changes due to irradiation. However, the comparison of results gained from ion beam irradiation, large-scale neutron irradiation, and a variety of experimental setups is not straightforward, and several effects have to be taken into account. It is the intention of this article to introduce the reader to the basic phenomena taking place and to point out the differences between classic reactor irradiations and ion irradiations. It will also provide an assessment of how accelerator-based ion beam irradiation is used today to gain insight into the damage in structural materials for large-scale engineering applications.
The pituitary gland of the coelacanth Latimeria chalumnae Smith.

Abstract Pituitary structure in the coelacanth Latimeria, the surviving member of the Crossopterygii, demonstrates features both shared and unique amongst the bony fishes. The neurohypophysis contains three areas of specialized neural contact. The anterior neurohypophysis comprises both a neurohemal organ—a median eminence—and an area of more direct, interdigitate contact with the pars distalis reminiscent of Amia. The predominant axon type of the median eminence contains a small monaminergic-type, dense-cored vesicle of 950 A diameter. A neurointermediate lobe complex consists of branching tubular processes of the posterior neurohypophysis and follicles of the pars intermedia. The former contain peptidergic-type axons with large dense-cored vesicles of 1960 A diameter which stain strongly as elementary neurosecretory granules (Knowles Type A). The saccus vasculosus is incompletely separated from the peptidergic posterior neurohypophysis. The tripartite pars distalis shows a more marked tendency toward compartmentalization relative to the lower Actinopterygii and the Dipnoi. Two major divisions of the pars distalis are evident on the basis of vascularization. The more orthodox proximal division is closely associated with the neurointermediate lobe and the portal vessels which appear to represent the major blood supply to this area. It comprises a purely acidophilic dorsal lobe (orangeophils and erythrosinophils), and a posterior lobe of mixed-cell type (orangeophils and basophils) which has a limited area of direct interdigitate neurohypophysial contact. The elongate extension of the pituitary so peculiar to the coelacanth comprises the rostral division which is connected only by a tubular hypophysial cavity to the remainder of the distalis. This virtually separated lobe has a substantial direct arterial supply derived from the internal carotids and contains relatively few chromophilic cells of basophil type in this immature female. The organization of the neurohypophysis in Latimeria is similar to that of other jawed fishes, particularly some relic actinopterygians. In contrast, the tripartite division of the pars distalis, the histologically separated rostral division with its direct arterial supply, basophil cell type, and close association with the carotid anastomosis, are unique features among the Osteichthyes, but are strongly reminiscent of the elasmobranch ventral lobe. Pituitary organization in Latimeria contrasts markedly with that of the lungfishes. The significance of this disparity in terms of the relationship of the two Orders of the Sarcopterygii (Romer) to each other, and of the unique features of the coelacanth in terms of its position as a sister group to the Rhipidistia, is discussed.
An F NMR Study of Bis(trifluoromethyl)phenyl Bacteriorhodopsin Analogs

Two bis-trifluoromethylated phenylretinal bacteriorhodopsin (bR) analogs were prepared and studied by F NMR and UV−vis spectroscopy. In contrast to those of visual pigments, only one fluorine signal was observed for the doubly labeled bR analogs. After considering different possible explanations, we believe the result probably reflects a more open hydrophobic pocket for the bR analogs allowing rapid equilibration (at the NMR scale) of the double labels. The extent of protein perturbation at the ortho position is different from that at the meta position.
Development and Validation of Parametric Models for Vector Tracking Loops

This paper develops parametric models from the existing vector architecture equations to explain the performance benefits of vector tracking loops. A theoretical analysis of the parametric models which are validated with simulation studies shows that internal aiding among loops is the key to the superior performance of the vector tracking architecture. A systematic methodology for comparing scalar and vector architectures with similar design parameters is also presented. From this, the conditions under which both architectures can perform comparably are identified. The analysis results presented in the paper lead to the following important conclusions. First, internal aiding, in addition to being responsible for vector loops' superior performance, allows easy propagation of errors among loops and, therefore, affects the fault tolerance capability of the vector tracking architecture. Second, well designed scalar tracking loops with external Doppler aiding can offer similar performance improvements while avoiding the complexity of the vector architecture.
Measurement of spontaneous morphologic variations in the electrocardiographic P-wave.

A real-time computer-oriented data acquisition and analysis system is described for measuring the spontaneous morphologic variations in the electrocardiographic P-wave. A waveform index is obtained by comparing each P-wave on a beat-by-beat basis with a reference P-wave. A graphic history of the P-wave morphology is produced by plotting this waveform index versus time. When structural changes in the P-wave are present the waveform index is further used to separate the P-waves into families and these families are averaged.
Intrapulmonary pressures in the newborn infant

Summary A pressure of from 20 to 30 cm. water is usually required to overcomethe factors resisting the expansion of the human lung at birth. To determine how much force the thorax of the newborn infant can exert against this resistance, the intrapulmonary pressures of forty-seven infants in the first few days of life were measured during respiration against partial or complete obstruction. Most of the thirty-four infants weighing more than 5 pounds developed intrapulmonary pressures of −40 cm. water during maximal inspiratory effort; ten of thirteen premature infants also achieved pressures of this degree, the other three reaching −26 and −32 cm. water. Collapsing inward of the chest wall was observed in only one infant. More correlation was observed between intrapulmonary pressure and general irritability and activity, than between intrapulmonary pressure and size or maturity of the infant.
A test problem for outflow boundary conditions—flow over a backward-facing step

A numerical solution for steady incompressible flow over a two-dimensional backward-facing step is developed using a Galerkin-based finite element method. The Reynolds number for the simulations is 800. Computations are performed on an extended channel length to minimize the effect of the outflow boundary on the upstream recirculation zones. A thorough mesh refinement study is performed to validate the results. Extensive profile data at several channel locations are provided to allow future testing and evaluation of outflow boundary conditions.