cssi/SciSciGPT-SciSciNet huggingface dataset:
Further evidence for the role of adenosine in

Experiments were performed on isolated, nonworking rat hearts perfused at constant pressure according to the Langendorff technique to evaluate the role of adenosine in hypercapnia-evoked coronary vasodilation. Hypercapnia/acidosis resulted in increases in heart rate and coronary flow rates in conjunction with a decrease in ventricular contractile tensions. The adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA, 10 microM) reduced the heart rate and enhanced CO2-evoked increases in coronary vascular flow. 5-Iodotubercidin (1 microM), an inhibitor of adenosine kinase, caused a reduction in heart rate and enhanced coronary flow rates during hypercapnic perfusion. Adenosine deaminase (1 U/ml) significantly attenuated CO2-evoked increases in coronary vascular flow. These results extend those of previous investigations implicating adenosine in the regulation of coronary flow during conditions of respiratory or metabolic acidosis.
Learning Processes in Development Planning : A Theoretical Overview and Case Study

Planners work with various kinds of organizations, sometimes to provide technical expertise and other times to facilitate communication between different organizations and interest groups. Planners are also important players in “organizational learning.” In this article, the authors describe how organizational practices change through learning. Drawing from the sociological literature on organizational behavior, the authors develop a conceptual model of organizational learning. This model is then applied to the case of a nongovernmental organization (NGO) engaged in development planning in western India. We show not only how learning processes have led to behavioral change in this NGO but also ways in which learning has been constrained.
Reconstruction of the image on the cartesian lattice from a finite number of projections in computed-tomographic imaging

The reconstruction of the image f(x, y) is from a finite number of projections on the discrete Cartesian lattice N × N is described. The reconstruction is exact in the framework of the model, when image is considered as the set of N 2 cells, or image elements with constant intensity each. Such reconstruction is achieved because of the following two facts. Each basis function of the tensor transformation is determined by the set of parallel rays, and, therefore, the components of the tensor transform can be calculated by ray-sums. These sums can be determined from the ray-integrals, and we introduce here the concept of geometrical, or G -rays to solve this problem. The examples of image reconstruction by the proposed method are given, and the reconstruction on the Cartesian lattice 7 × 7 is described in detail.
Using the minimum description length to discover the intrinsic cardinality and dimensionality of time series

Many algorithms for data mining or indexing time series data do not operate directly on the raw data, but instead they use alternative representations that include transforms, quantization, approximation, and multi-resolution abstractions. Choosing the best representation and abstraction level for a given task/dataset is arguably the most critical step in time series data mining. In this work, we investigate the problem of discovering the natural intrinsic representation model, dimensionality and alphabet cardinality of a time series. The ability to automatically discover these intrinsic features has implications beyond selecting the best parameters for particular algorithms, as characterizing data in such a manner is useful in its own right and an important sub-routine in algorithms for classification, clustering and outlier discovery. We will frame the discovery of these intrinsic features in the Minimal Description Length framework. Extensive empirical tests show that our method is simpler, more general and more accurate than previous methods, and has the important advantage of being essentially parameter-free.
1.3 µm Traveling Wave Interferometer Modulator For Instrument Applications

A Ti:LiNb03 interferometer modulator has been fabricated for instrument applications in the 1.3 μm wavelength region. It requires only 3.5 volts switching voltage, and has a fiber-to-fiber insertion loss of -4 dB. This includes a propagation loss of 2 dB and a fiber/device coupling loss of ~ 1 dB/end. Frequency response measurements indicate an optical 3 dB bandwidth of ~ 8 GHz. The corresponding drive voltage/bandwidth figure of merit of .44 volts/GHz is the lowest reported for a 1.3 um modulator.© (1987) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Physical vapor transport of cadmium telluride in closed ampoules

Abstract The dependence of the mass flux on the source material pretreatment, on the source temperature, and on the temperature difference between the source and transport product have been systematically investigated. Procedures have been developed yielding source materials of composition near that of the “congruently vaporizing” phase of CdTe. With this material, mass fluxes at moderate temperatures are observed which are up to about an order of magnitude larger than the highest reported in the literature for comparable conditions. Minute deviations from the “stoichiometric” composition reduce the mass flux by orders of magnitude. The experimental results are compared with theoretically predicted mass fluxes based on a diffusion limited transport process, and with other possible limitations reported in the literature. The high mass fluxes observed in this work at relatively low temperatures enable the vapor growth of large CdTe single crystals under conditions of practical importance.
Implications of expert systems for the operations of financial institutions

Abstract This paper discusses how expert systems can improve operation function of the various organizations in the financial services sector. We use a well-known conceptual framework known as “the service management model” (which consists of service strategy, service product design, service process design, and service delivery system) to discuss the managerial implications of expert systems employed to manage operations of the financial organizations. By viewing expert systems as enablers to improve the various components of the service management model, we demonstrate that expert systems in various financial institutions have assisted in accomplishing the service strategy by providing alternatives for improved service design as well as more quality-based delivery systems. The operations strategy based on performance measures such as dependability, efficiency. flexibility and quality can be enhanced by ES implementations; incorporating these systems into a company's service management model will enable an operations manager to increase the attainment of each measure.
Earth's Critical Zone and hydropedology: concepts, characteristics, and advances

Abstract. The Critical Zone (CZ) is a holistic framework for integrated studies of water with soil, rock, air, and biotic resources in the near-surface terrestrial environment. This most heterogeneous and complex region of the Earth ranges from the vegetation top to the aquifer bottom, with a highly variable thickness globally and a yet-to-be clearly defined lower boundary of active water cycle. Interfaces among different compartments in the CZ are critical, which provide fertile ground for interdisciplinary research. The reconciliation of coupled geological and biological cycles (vastly different in space and time scales) is essential to understanding the complexity and evolution of the CZ. Irreversible evolution, coupled cycling, interactive layers, and hierarchical heterogeneity are the characteristics of the CZ, suggesting that forcing, coupling, interfacing, and scaling are grand challenges for advancing CZ science. Hydropedology – the science of the behaviour and distribution of soil-water interactions in contact with mineral and biological materials in the CZ – is an important contributor to CZ study. The pedosphere is the foundation of the CZ, which represents a geomembrance across which water and solutes, as well as energy, gases, solids, and organisms are actively exchanged with the atmosphere, biosphere, hydrosphere, and lithosphere, thereby creating a life-sustaining environment. Hydropedology emphasizes in situ soils in the landscape setting, where distinct pedogenic features and soil-landscape relationships are essential to understanding interactive pedologic and hydrologic processes. Both CZ science and hydropedology embrace an evolutionary and holistic worldview, which offers stimulating opportunities through steps such as integrated systems approach, evolutionary mapping-monitoring-modeling framework, and fostering a global alliance. Our capability to predict the behaviour and evolution of the CZ in response to changing environment can be significantly improved if cross-site scientific comparisons, evolutionary treatment of organized complex systems, and deeper insights into the CZ can be made.
The Periplasmic Molecular Chaperone Protein SurA Binds a Peptide Motif That Is Characteristic of Integral Outer Membrane Proteins

Abstract The Escherichia coli SurA protein is a periplasmic molecular chaperone that facilitates correct folding of outer membrane porins. The peptide binding specificity of SurA has been characterized using phage display of heptameric peptides of random sequence. The consensus binding pattern of aromatic-polar-aromatic-nonpolar-proline amino acids emerges for both SurA and a SurA “core domain,” which remains after deletion of a peripheral peptidyl-proline isomerase domain. Isothermal titration calorimetry with a high affinity heptameric peptide of sequence WEYIPNV yields peptide affinities in the range of 1-14 μm for both SurA and its core domain. Although the peptide consensus aromatic-polar-aromatic-nonpolar-proline occurs infrequently in E. coli proteins, the less restrictive tripeptide motif aromatic-random-aromatic appears with greater-than-random frequency in outer membrane proteins and is prevalent in the “aromatic bands” of the porin β barrel structures. Thus, SurA recognizes a peptide motif that is characteristic of integral outer membrane proteins.
A History of Undergraduate Education for Public Health: From Behind the Scenes to Center Stage

Education for Public Health traces its roots to the Welch–Rose report of 1915. The Welch–Rose report defined education for public health as applied graduate education primarily for professionals such as physicians, nurses, and engineers who needed academic education and the latest research to help them take on leadership roles in governmental public health (1). The graduate and research focus of academic public health dominated the landscape for the better part of the twentieth century. Yet behind the scenes, changes were occurring that have led in the twenty-first century to new approaches to undergraduate public health education. The Society for Public Health Education (SOPHE) was founded in 1950. As was the practice of the era, membership required a graduate degree. A decade later, SOPHE began admitting members with an undergraduate degree and practice experience (2). Undergraduate programs supported by SOPHE have included community health and school health. The emergence of environmental health as a distinct field led to the development of environmental health programs at the bachelor’s degree level with a strong science emphasis. In 1967, the National Environmental Health Science & Protection Accreditation Council (EHAC) was established. East Tennessee State’s undergraduate environmental health program became the first accredited undergraduate program (3). When the Association of University Programs in Health Administration (AUPHA) was founded in the late 1940s, graduate degree programs formed the basis of eligibility for membership. Undergraduate programs were gradually added. By the late part of the century, AUPHA was offering a certification process for undergraduate health administration programs (4). During the last half of the twentieth century, undergraduate programs in public health and related fields were developed that either did not qualify for membership in SOPHE, EHAC, or AUPHA, or chose not to pursue such membership. According to the Association of Schools and Programs of Public Health (ASPPH), by 1992, there were 45 institutions that were offering one or more undergraduate degrees in a public health related field. By 2000, this number had risen to 76 (5). These early efforts to develop specialty degrees for undergraduates not only survived but have grown over the years. At the turn of the twenty-first century, they represented the major source of undergraduate education for public health.
Long-term shifts in snake populations: a California site revisited

The distribution and abundance of snakes along a transect across an ecotone from an oak woodland-chaparral mosaic to a more arid grassland in north-central California was surveyed. Of 11 taxa documented in the 1970s, 10 were observed in the 1990s; only Tantilla planiceps, a rare form in the 1970s, was absent in the 1990s. Nine of the 11 taxa were similar in abundance across sampling periods. Juvenile Pituophis catenifer and Crotalus viridis increased dramatically in the 1990s; adult Pituophis catenifer declined, whereas adult Crotalus viridis increased. Analysis of these two taxa indicated that abundance along the transect was approximately similar in the 1970s and 1990s; snakes were most abundant in the ecotone. Snake abundance was similar for the 1970s and 1990s in spite of increased road traffic, continued off-road vehicle use and sheep and cattle grazing, and collecting for the pet-trade. Additional study will be necessary to assess the apparent stability of this snake community.
Determination of Avrami parameters from calorimetric studies of precipitates in alloys: Methods to correct for the loss of early-time data

The kinetics of phase transformations, including diffusion-controlled precipitation, are frequently well described by the Avrami equation. The authors have presented methods for deriving Avrami parameters in cases where data are missing for early times. The first method involves re-plotting the experimental data for a series of shifts, [Delta]t, of the time origin (neglecting data falling earlier than the new time origin); calculating X(t), fraction of material transformed, vs. t for each [Delta]t; fitting the Avrami equation to X(t) to derive [tau] and m values; plotting the values as a function of [Delta]t; and extrapolating to [Delta]t = 0 to obtain the best values. A second, faster method may, at times, be suitably accurate: the authors use the 2-exponential simulation to approximate the data over the entire time range from 0 to [infinity]. They then calculate X(t) and carry out an Avrami fit to X(t) to determine [tau] and m values in fair agreement with those of the lengthier first method. A caveat is in order: The methods of the present paper should be applied with caution.
The relevance of economic data in the decision-making process for orbital launch vehicle programs, a U.S. perspective

Abstract Over the past fifteen years, major U.S. initiatives for the development of new launch vehicles have been remarkably unsuccessful. The list is long: NLI, SLI, and X-33, not to mention several cancelled programs aimed at high speed airplanes (NASP, HSCT) which would share some similar technological problems. The economic aspects of these programs are equally as important to their success as are the technical aspects. In fact, by largely ignoring economic realities in the decisions to undertake these programs and in subsequent management decisions, space agencies (and their commercial partners) have inadvertently contributed to the eventual demise of these efforts. The transportation revolution that was envisaged by the promises of these programs has never occurred. Access to space is still very expensive; reliability of launch vehicles has remained constant over the years; and market demand has been relatively low, volatile and slow to develop. The changing international context of the industry (launching overcapacity, etc.) has also worked against the investment in new vehicles in the U.S. Today, unless there are unforeseen technical breakthroughs, orbital space access is likely to continue as it has been with high costs and market stagnation. Space exploration will require significant launching capabilities. The details of the future needs are not yet well defined. But, the question of the launch costs, the overall demand for vehicles, and the size and type of role that NASA will play in the overall launch market is likely to influence the industry. This paper will emphasize the lessons learned from the economic and management perspective from past launch programs, analyze the issues behind the demand for launches, and project the challenges that NASA will face as only one new customer in a very complex market situation. It will be important for NASA to make launch vehicle decisions based as much on economic considerations as it does on solving new technical challenges.
Interconverting multiple bonds between molybdenum and tungsten atoms: oxidative-additions and reductive-eliminations from dinuclear centers

Abstract Analogies between the chemistry of mononuclear group 8, 9 and 10 transition elements and the chemistry of dinuclear molybdenum and tungsten compounds are noted. Just as the d8- and d6-configurations determine preferred coordination numbers, geometries, substitution patterns and the propensity for oxidative-addition or reductive-elimination, so does the MM bonding configuration influence the coordination chemistry and reactivity of dinuclear compounds. The presence of two metal atoms united by a multiple bond provides an electron source or sink for multi-electron redox reactions and a template for substrate assembly and coupling. The presence of two metal centers poses fascinating mechanistic questions concerning cooperative interactions between the metal atoms and the detailed reaction profile for even simple addition-elimination sequences. These general principles are illustrated in studies of the formation of M-M quadruple bonds by reductive-elimination from (MM)6+ centers and oxidative-additions leading to (MM)8+ and (M|M)10+ centers.
Coastal eutrophication assessment in the United States

Recent national assessments document that nitrogen-driven coastal eutrophication is widespread and increasing in the United States. This significant coastal pollution problem includes impacts including increased areas and severity of hypoxic and anoxic waters; alteration of food webs; degradation and loss of sea grass beds, kelp beds and coral reefs; loss of biodiversity; and increased incidences and duration of harmful algal blooms. In this paper, we review two comple- mentary approaches to assessing the causes and consequences of these trends, as well as potential remedies for them. The first is a national-scale assessment, drawn primarily from expert knowledge of those most familiar with the individual estuaries and integrated into a common analysis framework. The second approach, focused on the Mississippi/Atchafalaya basin - the largest US drainage basin - draws upon both quantitative and qualitative analyses within a comprehensive framework, Integrated Assessment.
A genetic map of citrus based on the segregation of isozymes and RFLPs in an intergeneric cross.

Isozymes and restriction fragment length polymorphisms were used as markers in the construction of a genetic map of the citrus nuclear genome. The map was based on the segregation of 8 isozyme, 1 protein, and 37 RFLP loci in 60 progeny of a cross of two intergeneric hybrids, ‘Sacaton’ citrumelo (Citrus paradisi Macf. x Poncirus trifoliata (L.) Raf.) and ‘Troyer’ citrange (C. sinensis (L.) Osbeck x P. trifoliata), often used as rootstocks. The map contains 38 of 46 studied loci distributed on ten linkage groups. A genome size of 1,700 cM was estimated from partial linkage data. Approximately 35% of the genome should be within 10 cM and 58% within 20 cM of the mapped markers. Eight loci in three linkage groups and 1 unlinked locus deviated significantly from Mendelian segregation.
Transcriptional Regulation of puc Operon Expression in Rhodobacter sphaeroides ANALYSIS OF THE CIS-ACTING DOWNSTREAM REGULATORY SEQUENCE

Both site-directed and spontaneous mutagenesis have been used to investigate the role of the cis-acting regulatory region between −92 and −1 base pair (bp) of the puc operon of Rhodobacter sphaeroides. The DNA sequence from −84 to −66 bp upstream of the 5′ end of the start site of puc operon transcription is essential for normal puc operon expression. This regulatory effect was exerted irrespective of the presence or absence of additional upstream regulatory sequences extending from −629 to −93 bp. It is likely that this region is involved in activator binding. Additionally, two regions of dyad symmetry centered at −42 and −17 bp are shown to be involved in oxygen repression of puc operon expression. Mutations within these regions of dyad symmetry were further subdivided on the basis of whether or not the upstream regulatory region was required to observe the mutant phenotype. Based upon these observations we conclude that these regions of dyad symmetry possessing the motif TGT-N12-ACA (where N represents any nucleotide) are involved in repressor binding with the puc operon promoter overlapping each of these dyad symmetries.
Fresh produce consumption and the association between frequency of food shopping, car access, and distance to supermarkets.

Abstract Background Fresh fruit and vegetables are important components of a healthy diet. Distance to a supermarket has been associated with the ability to access fresh produce. Methods A randomly sampled telephone survey was conducted with the main shopper for 3000 households in New Orleans, Louisiana in 2011. Individuals were asked where and how often they shopped for groceries, frequency of consumption of a variety of foods, and whether they had access to a car. Bivariate models assessed the relationship between four outcomes: car access, distance to the store patronized by the respondent, number of monthly shopping trips, and daily servings of produce. Structural equation modeling (SEM) was used to distinguish direct and indirect effects. Results In bivariate models, car access was positively associated with number of shopping trips and produce consumption while distance was inversely associated with shopping trips. In SEM models, produce consumption was not associated with car access or distance, but to the number of monthly shopping trips. Conclusion The frequency of shopping is associated with car access but a further distance deters it. Access to stores closer to the shopper may promote more frequent shopping and consumption of produce.
The development of control over complementary systems during the second year

Eleven infants were tested longitudinally at 16, 18, and 20 months to examine the nature and development of the invention of new means in problem solving. Each infant was administered a means-ends problem and a picture-showing task, both of which required orienting one sensorimotor system with respect to another. The means-ends problem used a transparent cylinder to control for representation in the Piagetian sense of symbolic evocation. Infants were unlikely to either orient the instrument to fit inside the cylinder or orient the picture relative to the experimenter until 20 months. Infants progressed through a predicted sequence from 16 to 20 months on both tasks. There was no contingency between orienting on both tasks until 20 months. The results challenge Piaget's representation model and support the hypothesis that invention at the end of the second year reflects the development of control over two complementary systems.
Metaanalysis of the effect of antenatal indomethacin on neonatal outcomes.

Objective The objective of the study was to determine whether indomethacin used as a tocolytic agent is associated with adverse neonatal outcomes. Study Design We used published guidelines of the Metaanalysis of Observational Studies in Epidemiology Group (MOOSE) to perform the metaanalysis. The search strategy used included computerized bibliographic searches of MEDLINE (1966-2005), PubMed (1966-2005), abstracts published in Obstetrics and Gynecology (1991-2005), abstracts published in Pediatric Research (1991-2005), and references of published manuscripts. Study inclusion criteria were publication in English, more than 30 deliveries less than 37 weeks' gestation, and meeting diagnostic criteria for individual neonatal outcomes. Exclusion criteria included case reports, case series, and multiple publications from the same author. Metaanalysis was performed using random effects model if there were more than 2 observational studies for a specific outcome. Eggers test was performed to exclude publication bias. Sensitivity analysis was performed to evaluate the effect of antenatal steroid exposure, gestation, and recent antenatal indomethacin exposure (duration of 48 hours or more between the last dose and delivery). Results Fifteen retrospective cohort studies and 6 case-controlled studies met inclusion criteria. Antenatal indomethacin was associated with an increased risk of periventricular leukomalacia (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.3-3.1). Recent exposure to antenatal indomethacin was associated with necrotizing enterocolitis (OR, 2.2; 95% CI; 1.1-4.2). Antenatal indomethacin was not associated with intraventricular hemorrhage, patent ductus arteriosus, respiratory distress syndrome, bronchopulmonary dysplasia, and mortality. Conclusion Antenatal indomethacin may be associated with an increased risk of periventricular leukomalacia and necrotizing enterocolitis in premature infants and therefore should be used judiciously for tocolysis.
Transcriptional profiling of non-small cell lung cancer cells with activating EGFR somatic mutations.

Background Activating somatic mutations in epidermal growth factor receptor (EGFR) confer unique biologic features to non-small cell lung cancer (NSCLC) cells, but the transcriptional mediators of EGFR in this subgroup of NSCLC have not been fully elucidated.
Estimation of Photovoltaic System Reliability and Performance Metrics

A framework to integrate reliability and performance analysis of grid-tied photovoltaic (PV) systems is formulated using Markov reward models (MRM). The framework allows the computation of performance metrics such as capacity and energy yield, and reliability metrics such as availability. The paper also provides an analytical method to compute the sensitivity of performance metrics to MRM-parameter variations. The approach to sensitivity analysis is demonstrated to be particularly useful to formulate optimal operational policies, e.g., repair strategies, as the impact of variations in model parameters on system performance can be rapidly evaluated. Case studies demonstrate several applications of the proposed framework, including analysis of residential and large utility-level installations, and emerging distributed inverter architectures.
Neutrino masses, mixing and hierarchy

Abstract We build a model to describe neutrinos based on strict hierarchy, incorporating as much as possible, the latest known data, for Δsol and Δatm, and for the mixing angles determined from neutrino oscillation experiments, including that from KamLAND. Since the hierarchy assumption is a statement about mass ratios, it lets us obtain all three neutrino masses. We obtain a mass matrix, Mν and a mixing matrix, U, where both Mν and U are given in terms of powers of Λ, the analog of the Cabibbo angle λ in the Wolfenstein representation, and two parameters, ρ and κ, each of order one. The expansion parameter, Λ, is defined by Λ 2 =m 2 /m 3 = Δ sol /Δ atm ≈0.16 , and ρ expresses our ignorance of the lightest neutrino mass m1, (m1=ρΛ4m3), while κ scales s13 to the experimental upper limit, s13=κΛ2≈0.16κ. These matrices are similar in structure to those for the quark and lepton families, but with Λ about 1.6 times larger than the λ for the quarks and charged leptons. The upper limit for the effective neutrino mass in double β-decay experiments is 4×10−3 eV if s13=0 and 6×10−3 eV if s13 is maximal. The model, which is fairly unique, given the hierarchy assumption and the data, is compared to supersymmetric extension and texture zero models of mass generation.
Time-dependent universal conductance fluctuations in mesoscopic Au wires: Implications

In cold, mesoscopic conductors, two-level fluctuators lead to time-dependent universal conductance fluctuations (TDUCFs) manifested as $1∕f$ noise. In Au nanowires, we measure the magnetic-field dependence of TDUCFs, weak localization (WL), and magnetic-field-driven UCFs before and after treatments that alter magnetic scattering and passivate surface fluctuators. Inconsistencies between ${L}_{\ensuremath{\phi}}^{\mathrm{WL}}$ and ${L}_{\ensuremath{\phi}}^{\mathrm{TDUCF}}$ strongly suggest either that the theory of these mesoscopic phenomena in weakly disordered, highly pure Au is incomplete, or that the assumption that the TDUCF frequency dependence remains $1∕f$ to very high frequencies is incorrect. In the latter case, TDUCFs in excess of $1∕f$ expectations may have implications for decoherence in solid-state qubits.
Examination of Mechanism of N-Acetyl-1-d-myo-inosityl-2-amino-2-deoxy-α-d-glucopyranoside Deacetylase (MshB) Reveals Unexpected Role for Dynamic Tyrosine *

Actinomycetes are a group of Gram-positive bacteria that includes pathogenic mycobacterial species, such as Mycobacterium tuberculosis. These organisms do not have glutathione and instead utilize the small molecule mycothiol (MSH) as their primary reducing agent and for the detoxification of xenobiotics. Due to these important functions, enzymes involved in MSH biosynthesis and MSH-dependent detoxification are targets for drug development. The metal-dependent deacetylase N-acetyl-1-d-myo-inosityl-2-amino-2-deoxy-α-d-glucopyranoside deacetylase (MshB) catalyzes the hydrolysis of N-acetyl-1-d-myo-inosityl-2-amino-2-deoxy-α-d-glucopyranoside to form 1-d-myo-inosityl-2-amino-2-deoxy-α-d-glucopyranoside and acetate in MSH biosynthesis. Herein we examine the chemical mechanism of MshB. We demonstrate that the side chains of Asp-15, Tyr-142, His-144, and Asp-146 are important for catalytic activity. We show that NaF is an uncompetitive inhibitor of MshB, consistent with a metal-water/hydroxide functioning as the reactive nucleophile in the catalytic mechanism. We have previously shown that MshB activity has a bell-shaped dependence on pH with pKa values of ∼7.3 and 10.5 (Huang, X., Kocabas, E. and Hernick, M. (2011) J. Biol. Chem. 286, 20275–20282). Mutagenesis experiments indicate that the observed pKa values reflect ionization of Asp-15 and Tyr-142, respectively. Together, findings from our studies suggest that MshB functions through a general acid-base pair mechanism with the side chain of Asp-15 functioning as the general base catalyst and His-144 serving as the general acid catalyst, whereas the side chain of Tyr-142 probably assists in polarizing substrate/stabilizing the oxyanion intermediate. Additionally, our results indicate that Tyr-142 is a dynamic side chain that plays key roles in catalysis, modulating substrate binding, chemistry, and product release.
Evaluation of Off-Flavor in Pond-Raised Channel Catfish following Partial Crop Harvest

Abstract Ponds used to raise channel catfish Ictalurus punctatus in the southeastern United States often contain more food-sized catfish than processors can accept at one time. Fish remaining after initial harvest are returned to the pond and harvested again as soon as possible based upon processor demands. Some catfish farmers report that catfish crops initially declared “on-flavor” appear to develop off-flavors soon after the first harvest, which postpones harvest of the remaining population and delays subsequent production. We conducted a 9-month study on a commercial catfish farm in northwest Mississippi to determine whether fish systematically develop off-flavors after partial fish harvest and, if so, the type and origin of the flavor. Channel catfish and water samples were obtained from 12 ponds before initial harvest and then at intervals for 2 weeks after harvest. Water and catfish fillet samples were analyzed for geosmin and 2-methylisoborneol (MIB). Phytoplankton were identified and counted micr...
Derivation of the Singh-Yu Infiltration Equation Using Entropy Theory

Using the entropy theory, this note derives the Singh-Yu infiltration equation which is based on two simple constraints: (1) the total probability and (2) the mean logarithmic effective infiltration. The entropy theory permits a probabilistic characterization of the potential infiltration rate and hence the probability density function underlying the Singh-Yu infiltration equation. It also permits a quantitative assessment of the uncertainty of the infiltration yielded by the equation.
Fractal measures and mean p-variations

Abstract Recently Strichartz proved that if μ is locally uniformly α-dimensional on R d, then , where 0 ⩽ α ⩽ d, and BT denotes the ball of radius T center at 0; if μ is self-similar and satisfies a certain open set condition, he also obtained a formula for the α so that 0 lim sup T → ∞ ( 1 T d − α ) ∝ B T ¦( μ f ) \ s| 2 . The α can serve, in some sense, as the dimensional index of the measure μ. By using the mean p-variation and the Tauberian theorems, we extend the first inequality and its variants to p, q forms, and give necessary and sufficient conditions on μ for such inequalities to hold; we then use the mean quadratic variation to study some self-similar measures μ on R which do not satisfy the open set condition: the μ's that are constructed from S 1 x = ϱx, S 2 x = ϱx + (1 − ϱ), 1 2 with weights 1 2 each. The index α for μ corresponding to ϱ = (√5 − 1) 2 is calculated. The expression for such α is significantly different from the one obtained by Strichartz.
Environmental health criteria for disaster relief and refugee camps

The very subjective nature of most environmental health criteria for disaster relief and refugee camps makes interpretation of minimum quantities of potable water and separation distances from sources of pollution difficult, even for the trained environmental health professional. A review of the literature and a survey carried out with international environmental health professionals were conducted to summarize both the least‐preferred and most‐preferred parameters for enhanced environmental health services in such camps. The survey was conducted using a form of decision analysis, modified from the Simple Multiattribute Rating Technique. A campsite evaluation form was prepared using the selected criteria, after converting them to utilities. The form was used to evaluate existing refugee camps in Thailand. Camp environmental health scores were then compared to selected environmentally‐associated diseases. Results of that evaluation suggest that the environmental health criteria and the camp rating methodol...
Effect of Examining Half the Teeth in a Partial Periodontal Recording of Older Adults

Limited evidence to date has suggested that half-mouth examinations can be used in epidemiological surveys for accurate estimation of the prevalence of periodontal conditions. This study investigated the accuracy and efficiency of half-mouth periodontal examinations of mesial and buccal sites by comparing whole-mouth findings from those sites with findings that would have been obtained by examining only two randomly selected quadrants of teeth in three older dentate adult populations: 263 whites in Iowa, 309 whites in North Carolina, and 384 blacks in North Carolina. Mean half-mouth scores for gingival recession, pocket depth, attachment loss, and Extent and Severity Index were almost identical to those of mean whole-mouth scores, with correlations between means exceeding 0.93. However, the proportions of the population having selected levels of moderate or severe periodontal disease in mesial and buccal sites were underestimated by as much as 13%. This study showed that half-mouth examinations can be acc...
Comments on marginal deformations in open string field theory

In this short Letter we present a class of remarkably simple solutions to Witten's open string field theory that describe marginal deformations of the underlying boundary conformal field theory. The solutions we consider correspond to dimension-one matter primary operators that have non-singular operator products with themselves. We briefly discuss application to rolling tachyons.
REGULATION OF FINE ROOT DYNAMICS BY MAMMALIAN BROWSERS IN EARLY SUCCESSIONAL ALASKAN TAIGA FORESTS

The effects of browsing by moose and snowshoe hares on fine root production, mortality, and decomposition in early successional forest ecosystems along the Tanana River floodplain in interior Alaska were studied over a 3-yr period using minirhizotrons placed inside and outside large permanent exclosures. Fine root production and mortality varied seasonally, with greatest rates of production occurring during June each year, and greatest rates of mortality occurring in fall and over winter. Annual production and mortality during 1993, a year of unusually low precipitation, were significantly higher than during either 1992 or 1994. Aboveground herbivory significantly reduced monthly rates of fine root production, and on an annual basis, fine root production of browsed plots (311.4 ± 31.7 mm·tube−1·yr−1) was significantly less than that of unbrowsed plots (453.8 ± 49.8 mm·tube−1·yr−1) when averaged over 3 yr. Because herbivory had less of an effect on monthly or annual rates of fine root mortality, fine root ...
Comparison of SCC Thresholds and Environmentally Assisted Cracking in 7050-T7451 Aluminum Plate

Aerospace alloys, often aluminums, are frequently exposed to corrosive environments resulting from naval service. These environments may produce significant changes in crack growth characteristics in these materials. An experiment was designed to characterize the effects of environment on crack growth thresholds and fracture characteristics for existing cracks in aluminum 7050-T7451 plate material. This data will be comparatively analyzed against aluminum 7075-T7631, an alloy with known susceptibility to corrosion, in order to determine a relative susceptibility of 7050-T7451, generally considered a superior aluminum alloy in terms of strength and corrosion resistance. The resulting data and subsequent analysis can in turn be used in more accurate determination of aircraft component service life in common corrosive environments experienced by aircraft in naval service.
CNS wide simulation of flow resistance and drug transport due to spinal microanatomy

Spinal microstructures are known to substantially affect cerebrospinal fluid patterns, yet their actual impact on flow resistance has not been quantified. Because the length scale of microanatomical aspects is below medical image resolution, their effect on flow is difficult to observe experimentally. Using a computational fluid mechanics approach, we were able to quantify the contribution of micro-anatomical aspects on cerebrospinal fluid (CSF) flow patterns and flow resistance within the entire central nervous system (CNS). Cranial and spinal CSF filled compartments were reconstructed from human imaging data; microscopic trabeculae below the image detection threshold were added artificially. Nerve roots and trabeculae were found to induce regions of microcirculation, whose location, size and vorticity along the spine were characterized. Our CFD simulations based on volumetric flow rates acquired with Cine Phase Contrast MRI in a normal human subject suggest a 2-2.5 fold increase in pressure drop mainly due to arachnoid trabeculae. The timing and phase lag of the CSF pressure and velocity waves along the spinal canal were also computed, and a complete spatio-temporal map encoding CSF volumetric flow rates and pressure was created. Micro-anatomy induced fluid patterns were found responsible for the rapid caudo-cranial spread of an intrathecally administered drug. The speed of rostral drug dispersion is drastically accelerated through pulsatile flow around microanatomy induced vortices. Exploring massive parallelization on a supercomputer, the feasibility of computational drug transport studies was demonstrated. CNS-wide simulations of intrathecal drugs administration can become a practical tool for in silico design, interspecies scaling and optimization of experimental drug trials.
The Dim Light Melatonin Onset, Melatonin Assays and Biological Rhythm Research in Humans

The most useful marker for human circadian phase position is the dim light melatonin onset (DLMO). This is optimally obtained by sampling blood or saliva in the evening at intervals of 30 min or less.
A history of aesthetic conservation in California.

Abstract In spite of early indifference to the scenic qualities of California and the exploitative attitude of the gold miners, lumbermen and other settlers, the state's landscape played a central and symbolic role in the emergence of the conservation movement in the second half of the nineteenth century. This paradox was largely due to the fortuitous fact that California, containing what was later described as some of the finest scenery in the world, was opened up at the height of the nature-oriented Romantic Movement centered in the eastern states. This paper explores the events and circumstances which have contributed to the present-day, broadly based concern for environmental quality in California. The establishment of Yosemite Valley as a preserved landscape in 1864 initiated, and gave focus to, the conservation movement in the United States. In California, its supporters included wealthy outdoorsmen who gave their time and money to the cause, scientists and university intellectuals who defined the objectives, and impassioned naturalists such as John Muir who provided an emotional framework. The designation of national parks in California and elsewhere, and ultimately an appropriate agency to administer them, was a major achievement of the movement. A leader in the campaign was the Sierra Club of California, founded in 1892. Its goals included the protection of the environmental quality and natural resources of the state. In the nineteen-twenties, increased population together with improved transportation, especially the automobile, contributed to a widespread popularity of outdoor recreation and a demand for more places to enjoy it. State and regional parks were established in mountain and coastal areas of California to satisfy the demand and at the same time take pressure off the national parks. The high quality and success of the California State Park system was largely due to the abundant scenic resources available and the public's willingness to pay for it. The post-war years brought unprecedented growth and increasing conflict of interest between short-term economics, the immediate demands of society and the longer-term, less definable values of resource conservation. In the nineteen-sixties and -seventies a series of controversial cases attracted widespread public attention, resulting in a greater awareness and vigilance on the part of the electorate. Several important battles have been won and some important conservation oriented legislation has been passed. Several related commissions and agencies have been established. The result is that California has become a testing ground for systems of controlling the impact of change on the environment, including scenic quality and the resolution of environmental conflicts.
Triazine absorption by excised corn root tissue and isolated corn root protoplasts

Abstract Absorption of four triazine herbicide analogs [ametryn (2-(ethylamino)-4-(isopropylamino)-6-(methylthio)- s -triazine), atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)- s -triazine), atratone (2-methoxy-4-(ethylamino)-6-(isopropylamino)- s -triazine), and hydroxyatrazine (2-hydroxy-4-(ethylamino)-6-(isopropylamino)- s -triazine)] was compared using excised corn ( Zea mays L.) root segments and isolated corn root protoplasts. The tissue absorbed ametryn, atrazine, and atratone for only 20 min. Ametryn and atrazine permeated tissue to passive equilibrium with the ambient solution in 10 min. Atratone permeated to 65 and 82% of passive equilibrium in 10 and 30 min, respectively. In contrast, hydroxyatrazine concentration in tissue was only 15 and 70% of the ambient concentration at 30 min and 24 hr, respectively. However, hydroxyatrazine permeated frozen/thawed tissue to 90% of passive equilibrium in 10 min. Protoplast absorption of ametryn and atratone was complete in 10 sec; hydroxyatrazine absorption by protoplasts did not reach a plateau until 5 min. Protoplasts absorbed the triazines to greater than passive equilibrium. Three kinetically homogeneous pools were detected for ametryn, atrazine, and atratone, whereas elution of hydroxyatrazine produced four pools. The three pools for atrazine were confounded by metabolism of atrazine to hydroxyatrazine. Pools for the triazines could not be identified as the free space, cytoplasm, and vacuole as proposed previously for mineral ions. Although the plasma membrane impeded diffusion of hydroxyatrazine, all analogs penetrated into the symplast.
A Tax Reform That Falls Flat

Even progressives these days are discussing ways to increase tax revenues that do not require an increase in progressive income taxes. The reason is that increasing income taxes on the rich is a no-go politically. But is a flat tax a reasonable replacement? Not at all, argues this economist.
Effect of insulin resistance and hyperglycemia on proinsulin release in a primate model of diabetes mellitus.

An elevated plasma proinsulin (PI) to immunoreactive insulin (IRI) ratio occurs in relatives of patients with insulin-dependent diabetes mellitus and in subjects with non-insulin-dependent diabetes mellitus. To determine whether this alteration is the result of B-cell dysfunction and/or insulin resistance, we infused nicotinic acid for 3 weeks to produce insulin resistance in five adolescent male baboons before and after the administration of streptozocin (200 mg/kg). We measured basal PI and IRI levels and the acute incremental PI (APIR) and IRI (AIRIR) responses to iv arginine. The quantity of IRI comprised of PI was calculated in the basal state (PI/IRI) and following arginine injection (APIR/AIRIR). Streptozocin administration did not change the fasting plasma glucose (FPG) compared to that in the normal animals (4.7 +/- 0.3 vs. 4.3 +/- 0.2 mM) but raised the PI/IRI (16.4 +/- 3.4 vs. 5.9 +/- 1.7%) and APIR/AIRIR (7.1 +/- 1.0 vs. 2.8 +/- 1.0%) due to a concurrent reduction in IRI and increase in PI con...
Nuclear transport: Randy couples

The recently solved structures of the Ran GTPase with a Ran-binding domain and with karyopherin-beta2 have revealed unusually tight embraces that provide important insights into the mechanism of nuclear transport and the many ways in which common protein folds are adapted to perform very different functions.
What happened to blood substitutes

Abstract Concerns about the safety and adequacy of the blood supply have fostered twenty years of research into the so-called “blood substitutes” among them the oxygen carriers based on modified hemoglobin. Although none of these materials has yet been licensed for use in North America or Europe, the results of research and clinical trials have increased our understanding of oxygen delivery and its regulation. In particular, the examination of the basis for the vasoactivity observed with some of the hemoglobin based oxygen carriers has led to the insight that several colligative properties of hemoglobin solutions, such as their diffusion coefficient for oxygen, viscosity and colloid oncotic pressure, are important determinants of efficacy.