cssi/SciSciGPT-SciSciNet huggingface dataset:
Studies of mammalian chromosome replication. II. Evidence for the existence of defined chromosome replicating units.

Sister chromatids of metaphase chromosomes can be differentially stained if the cells have replicated their DNA semiconservatively for two cell cycles in a medium containing 5-bromodeoxyuridine (BrdU). When prematurely condensed chromosomes (PCC) are induced in cells during the second S phase after BrdU is added to the medium, the replicated chromosome segments show sister chromatid differential (SCD) staining. Employing this PCC-SCD system on synchronous and asynchronous Chinese hamster ovary (CHO) cells, we have demonstrated that the replication patterns of the CHO cells can be categorized into G1/S, early, early-mid, mid-late, and late S phase patterns according to the amount of replicated chromosomes. During the first 4 h of the S phase, the replication patterns show SCD staining in chains of small chromosome segments. The amount of replicated chromosomes increase during the mid-late and late S categories (last 4 h). Significantly, small SCD segments are also present during these late intervals of the S phase. Measurements of these replicated segments indicate the presence of characteristic chromosome fragment sizes between 0.2 to 1.2 μm in all S phase cells except those at G1/S which contain no SCD fragments. These small segments are operationally defined as chromosome replicating units or chromosomal replicons. They are interpreted to be composed of clusters of molecular DNA replicons. The larger SCD segments in the late S cells may arise by the joining of adjacent chromosomal replicons. Further application of this PCC-SCD method to study the chromosome replication process of two other rodents, Peromyscus eremicus and Microtus agrestis, with peculiar chromosomal locations of heterochromatin has demonstrated an ordered sequence of chromosome replication. The euchromatin and heterochromatin of the two species undergo two separate sequences of decondensation, replication, and condensation during the early-mid and mid-late intervals respectively of the S phase. Similar-sized chromosomal replicons are present in both types of chromatin. These data suggest that mammalian chromosomes are replicated in groups of replicating units, or chromosomal replicons, along their lengths. The organization and structure of these chromosomal replicons with respect to those of the interphase nucleus and metaphase chromosomes are discussed.
The Possible Role of Zearalenone in the Floral Gradient in Nicotiana tabacum L.

Summary After plants entered the reproductive stage, the buds of a day-neutral tobacco (Nicotiana tabacum L. cv. Samson) developed in situ according to the following characteristic order: the apical bud, the lateral buds and three to four axillary buds below the apical bud produced inflorescences first, the next one or two lower axillary buds remained quiescent. The bud just below this zone developed predominantly into a floral branch. If the plant was allowed to grow in favorable conditions, the axillary buds located below the predominantly-developing-floral-branch (PDF) also remained quiescent and another axillary bud just below these quiescent buds developed predominantly. Such a growth model of axillary buds was expressed in the axillary buds of PDF and plants that were decapitated. The distribution of endogenous zearalenone (ZEN) in the stem was in correlation to this model, that is, there were higher levels of ZEN in the nodes at the upper side of which the predominantly-developing-bud (PDB) was located than the nodes at the lower side of which the same PDB was located. The results suggested that ZEN may be one of the important floral stimuli of day-neutral tobacco and is related to the floral gradient in tobacco shoot.
The Mediating Roles of Stress and Maladaptive Behaviors on Self-Harm and Suicide Attempts Among Runaway and Homeless Youth

Runaway and homeless youth often have a constellation of background behavioral, emotional, and familial problems that contribute to stress and maladaptive behaviors, which, in turn, can lead to self-harming and suicidal behaviors. The current study examined the roles of stress and maladaptive behaviors as mediators between demographic and psychosocial background characteristics and self-injurious outcomes through the lens of the stress process paradigm. The model was tested in a sample of runaway and homeless youth from Los Angeles County (N = 474, age 12–24, 41 % female, 17 % White, 32.5 % African American, 21.5 % Hispanic/Latino). Background variables (gender, age, sexual minority status, parental drug use history, and emotional distress) predicted hypothesized mediators of maladaptive behaviors and recent stress. In turn, it was hypothesized that the mediators would predict self-harming behaviors and suicide attempts in the last 3 months. Females and LGBT (lesbian, gay, bisexual, transgender) youth were more likely to have self-harmed and attempted suicide; younger participants reported more self-harming. The mediating constructs were associated more highly with self-harming than suicide attempts bivariately, although differences were modest. Maladaptive behaviors and recent stress were significant predictors of self-harm, whereas only recent stress was a significant predictor of suicide attempts. All background factors were significant predictors of recent stress. Older age, a history of parental drug use, and greater emotional distress predicted problem drug use. Males, younger participants, and participants with emotional distress reported more delinquent behaviors. Significant indirect effects on self-harming behaviors were mediated through stress and maladaptive behaviors. The hypothesized paradigm was useful in explaining the associations among background factors and self-injurious outcomes and the influence of mediating factors on these associations.
DNA sequence insertion and evolutionary variation in gene regulation

Current evidence on the long-term evolutionary effect of insertion of sequence elements into gene regions is reviewed, restricted to cases where a sequence derived from a past insertion participates in the regulation of expression of a useful gene. Ten such examples in eukaryotes demonstrate that segments of repetitive DNA or mobile elements have been inserted in the past in gene regions, have been preserved, sometimes modified by selection, and now affect control of transcription of the adjacent gene. Included are only examples in which transcription control was modified by the insert. Several cases in which merely transcription initiation occurred in the insert were set aside. Two of the examples involved the long terminal repeats of mammalian endogenous retroviruses. Another two examples were control of transcription by repeated sequence inserts in sea urchin genomes. There are now six published examples in which Alu sequences were inserted long ago into human gene regions, were modified, and now are central in control/enhancement of transcription. The number of published examples of Alu sequences affecting gene control has grown threefold in the last year and is likely to continue growing. Taken together, all of these examples show that the insertion of sequence elements in the genome has been a significant source of regulatory variation in evolution.
Escalated or Suppressed Cocaine Reward, Tegmental BDNF, and Accumbal Dopamine Caused by Episodic versus Continuous Social Stress in Rats

The neural link between ostensibly aversive stress experiences and intensely rewarding drug taking remains to be delineated. Epidemiological data associate stress and the abuse of various drugs, and experimental data identify the conditions that determine how episodic social stress intensifies the motivation for cocaine and the actual self-administration of cocaine. Two types of social stress have been the focus of experimental study in Long–Evans rats, since they engender divergent changes in drug- or sugar-rewarded behavior and in neuroadaptation. Episodic social defeat stress consists of four brief confrontations between the experimental rat and an aggressive resident rat of the Long–Evans strain over the course of 10 d. Subordination stress involves the continuous exposure to an aggressive resident for 5 weeks, while living in a protective cage within the resident's home cage with brief daily confrontations. These stress experiences result in (1) increased intravenous cocaine self-administration under a fixed ratio schedule with prolonged binge-like access in episodically defeated intruder rats but suppressed cocaine intake by continuously subordinate rats; (2) deteriorated sugar preference and intake and decreased exploratory behavior in subordinate, but not intermittently defeated, rats; and (3) a sensitized dopamine (DA) response in the nucleus accumbens via in vivo microdialysis and increased tegmental brain-derived neural growth factor (BDNF) in episodically defeated rats, whereas the continuously subordinate rats show suppression of the DA and BDNF responses. These divergent neuroadaptations to social stress may represent the substrates for the intensification of cocaine “bingeing” relative to the anhedonia-like deterioration of reward processes during subordination stress.
Effect of puromycin aminonucleoside on RNA synthesis in L cells.

Puromycin aminonucleoside has recently been shown to be a potent inhibitor of RNA synthesis in L cells ( Farnham, 1965 ). In the present studies, RNA from normal and aminonucleoside-treated cells has been fractionated by sucrose density-gradient centrifugation and analyzed for base composition. At a time when aminonucleoside had produced about 50% inhibition in over-all RNA synthesis, there appeared to be a relative preservation of S-RNA‡ and M-RNA synthesis. Calculations, made on the basis of base composition analyses, indicated that whereas R-RNA synthesis in the aminonucleoside-treated cells was inhibited by about 85%, M-RNA synthesis was inhibited by about 10%.
The election trap: the cycle of post-electoral repression and opposition fragmentation in Lukashenko's Belarus

Recent work on competitive authoritarianism has not explored the full consequences of electoral participation for opposition movements. While prominent work argues that the government must employ a mix of side-payments and repression to fragment opposition to its rule, Belarus’ history since the ascension of President Alexander Lukashenko in 1994 shows that the opposition has been repressed after most parliamentary and presidential elections without any substantial co-optation. I argue that electoral contestation and subsequent post-electoral repression have led to the Belarusian opposition's fragmented state. This state is grounded in competition for foreign aid, which creates a need among Belarusian opposition leaders to demonstrate their ability to mobilize support through campaigns. Invariably, successful opposition leaders emerge as the principal challengers to the regime, leading to their arrest or exile. Repression then fosters division within anti-government movements and restarts the cycle for ne...
Cardiovascular Disease Risk in Adult Women with Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is a common autosomal recessive disorder characterized by impaired cortisol biosynthesis, with or without aldosterone deficiency, and androgen excess. Patients with the classic (severe) form also have epinephrine deficiency. Patients with CAH have an increased prevalence of risk factors for cardiovascular disease including obesity, hypertension, and insulin resistance. Androgen excess in women appears to be an additional risk factor for cardiovascular disease. Carotid intima-media thickness, a measure of subclinical atherosclerosis, also has been found to be increased in adults with CAH. The multiple hormonal imbalances present in the adult woman with CAH, in combination with chronic glucocorticoid therapy, contribute to cardiovascular disease risk. Further investigation of the predisposition to cardiovascular disease in women with CAH is warranted. Longitudinal studies are needed, and interventions targeting obesity, insulin resistance, hypertension, and hyperandrogenism may offer improved outcome.
Reactions in the aqueous environment of low molecular weight organic molecules

Abstract The origin of small organic molecules in surface waters of the United States, for the most part, stems from industrial, urban and agricultural sources. Agricultural materials were examined, particularly the chlorinated pesticides and herbicides, to determine concentration ranges within which the characteristic interactions of these solutes could be defined. It was found that chlorinated hydrocarbon concentrations of bottom sediments at selected locations range from 5 ng/kg (nanograms per kilogram) to 3.5 μg/kg (micrograms per kilogram), and in water from 5 ng/l to 0.06 μg/l. Herbicide concentrations in water ranged from 5 ng/l to 1.5 μg/l for the same samples. Total organic carbon concentrations at these locations ranged from less than 0.1 mg/l to 42 mg/l (milligrams per litre).
Pattern recognition assessment of water quality data: Coal strip mine drainage

Abstract The problem of assessing the impact of a pollutant source on a stream is often attacked by making numerous chemical and physical measurements at selected sites on the stream as a function of time. Although no distinct methodology exists for interpreting these data, pattern recognition and multivariate statistical methods are applicable. Results are presented for applying these methods to chemical measurements taken on a creek in Colorado receiving ground water flow from a strip coal mine. The results show that the impact is substantial, with a primary impact due to predominant dissolved solids buffered along the length of the creek probably by carbonate and sulfate precipitation of the major cations. Several additional conclusions are drawn, and the effect of substantial amounts of missing data on the results of the study is determined.
The Measurement of School Engagement Assessing Dimensionality and Measurement Invariance Across Race and Ethnicity

The purposes of this study were to (a) assess the measurement of school engagement in prior research that used the National Educational Longitudinal Study of 1988 (NELS:88), (b) systematically develop an improved measurement model for school engagement, and (c) examine the measurement invariance of this model across racial and ethnic groups. Results from confirmatory factor analyses indicated that school engagement should be measured as a multidimensional concept. A higher order measurement model in which behavioral and psychological engagement are second-order latent variables that influence several subdimensions is consistent with the data. Results from a series of multiple group analyses indicated that the proposed measurement model exhibits measurement invariance for White, African American, Latino, and Asian students. Therefore, it is appropriate to compare the effects of the dimensions of engagement across these groups. The results demonstrate the advantages of confirmatory factor analysis for enhancing the understanding and measurement of school engagement.
Introduction to Special Issue (Part 1): Broadening Participation in Computing Education

This special issue includes the first set of articles addressing broadening participation in computing education. The articles span the stages of the pipeline, from introducing middle school children to computer science to retaining underrepresented groups at the university level. The preface presented here outlines the need for increasing the participation of underrepresented minorities, women, and people with disabilities in the development of technology. In addition, the preface summarizes the six articles included in this first (of two) issues on broadening participation.
Elastohydrodynamic lubrication simulation of O-ring and U-cup hydraulic seals

The recent development of an elastohydrodynamic lubrication rod seal model has made possible the simulation of hydraulic seal performance for design and selection purposes. This model consists of c...
Captain America vs. Wonder Woman

Both books tentatively concern the same phenomena: how have superheroes – in this case Captain America and Wonder Woman – remained relevant since their ‘birth’, during or immediately before World W...
Concerning the management of pain associated with herpes zoster and of postherpetic neuralgia

Abstract This simple method of achieving substantial pain control in patients with documented herpes zoster and postherpetic neuralgia has been effective in each of the patients in whom it has been used (the most recent 12 cases have been summarized for this report). It has been more effective than narcotic analgesics, oral anti-inflammatory analgesics, sedatives, tranquilizers, TENS, hypnosis and the wide variety of operative measures we have tried in the past. Although it was initially used pragmatically, there is now a reasonable rationale for its effectiveness that can be proposed based on more recent insights into the anatomy and neurophysiology of cutaneous nociceptors and the neuropharmacology of aspirin. In view of the widely held persuasion that the management of pain syndromes associated with herpes zoster (especially severe postherpetic neuralgia) is an unsatisfactory and frustrating venture, it seemed reasonable to report these more favorable clinical observations.
Purification of galactose-1-phosphate uridylyltransferase from human placenta☆

Abstract Galactose-1-phosphate uridylyltransferase (uridine diphosphoglucose: α- d -galactose-1-phosphate uridylyltransferase, EC 2.7.7.12) has been purified 4000-fold from human placenta in four chromatographic steps using DEAE-cellulose, hydrocylapatite, ethyliminohexylagarose, and Sephacryl S-200. The specific activity of the homogeneous enzyme was 56 units/mg protein. The placental enzyme consists of two similar subunits, each of molecular weight about 48,000. The placental enzyme was similar to published results for the red cell enzyme (V. P. Williams, Arch. Biochem. Biophys. , 1978, 191, 182–191) with respect to subunit molecular weight, electrophoretic migration, and immunological properties. The more purified fractions of the placental enzyme invariably contained a glycoprotein which was removed in the gel filtration step. After this glycoprotein was removed, the enzyme was very labile and only about 20% of the catalytic activity was recovered.
Understanding intranets in the context of end-user computing

In this paper, we examine the adoption and use of organizational intranets as an extension of the end-user computing movement. This perspective provides a background against which the rapid proliferation of organizational intranets in the 1990s can be compared and contrasted with the explosion of personal computers and end-user computing in the 1980s. Our retrospective analysis of end-user computing is based on academic and business journal literature. Our contemporary analysis of intranet development and use relies on data from a large-scale study of intranets in US firms. We examine similarities with early EUC efforts, such as the initial grass-roots, multiple adoption of PC technologies, that were followed by efforts to standardize and integrate technological "islands." We also highlight ways in which organizational experiences with intranets may diverge from earlier EUC experiences. Our discussion of these organizational experiences and practices draws on institutional theory to understand how and why organizational adoption and use of information technologies may differ from those of the past in important ways that require rethinking of current practices. In particular, we focus on the issues related to intranet integration and to the evolving roles of intranet end-users and IT professionals.
QUALITY ASSURANCE SOFTWARE FOR PERSONAL COMPUTER

Demonstration Project 89 on Quality Management was created to provide guidance on the use of practical and effective procedures to assure that the level of quality designed into the plans and specifications is actually achieved in the constructed product. One part of this effort is the distribution of a software package consisting of several interactive programs developed for use on the personal computer. These extremely user-friendly programs make it possible to analyze both pass/fail and pay adjustment acceptance procedures, construct operating characteristic curves, plot control charts, experiment with computer simulation, perform statistical comparisons of data sets, demonstrate the unreliability of decisions based on a single test result, and explore the effectiveness of stratified random sampling. This comprehensive software package provides highway engineers with the necessary tools to learn why some statistical procedures are inherently superior to others and how to incorporate this knowledge into...
Problems that Teach the Obvious but Difficult.

(1988). Problems that Teach the Obvious but Difficult. The American Mathematical Monthly: Vol. 95, No. 3, pp. 254-257.
Solar Microwave Bursts and Injection Pitch-Angle Distribution of Flare Electrons

We calculate the time variation of the energy and pitch angle of high-energy electrons injected into a magnetic loop and subsequently trapped there because of magnetic mirroring. We use the evolving distribution in the calculation of gyrosynchrotron emission, as an aid to interpretation of a particular microwave burst observed using the Owens Valley Solar Array (OVSA) during a GOES class C2.8 flare on 1993 June 3. The electrons are assumed to have a Gaussian pitch-angle distribution, whose width and mean pitch angle are calculated as they evolve in time, taking into account the electron energy loss and a specific magnetic loop structure set as a model for the target active region. Various temporal behaviors of the microwave spectrum are found as a function of injection and trap conditions, which can be used to infer some of the injection properties directly from the observed microwave spectra. As a main result we found that initial pitch-angle distribution plays an important role in the microwave spectral evolution. This is largely due to the fact that pitch-angle diffusion of electrons under Coulomb collisions markedly differs at those electron energies to which the microwave spectrum is sensitive. This effect cannot be reproduced by adjusting the trap properties and therefore could be used to determine whether the initial pitch-angle distribution is isotropic or narrowly beamed. The microwave burst spectra observed during the 1993 June 3 flare are found to be most consistent with the hypothesis of an initially narrow beamed injection (≤30°) into a low-density (~4 × 109 cm-3) magnetic trap. This result explains the observed asymmetric microwave time curve consisting of a relatively short rise (~32 s) and a long decay (≥5 minutes) in terms of a transport effect rather than acceleration characteristics. The physical connection of the proposed microwave model to hard X-ray models in thin/thick targets is briefly discussed.
Lethal thromboembolism and its prevention in pelvic surgery: A review

Abstract Five hundred thousand new cases of pulmonary embolism occur annually in the United States and at least 10% of these are fatal. A survey of the members of the Felix Rutledge Society reveals that 84.5% of its members use low-dose heparin prophylactically in high-risk patients. The data supporting the efficacy of thromboembolism prophylaxis are reviewed. Four possible reasons why low-dose heparin is not used by all pelvic surgeons are discussed. The conclusion is that despite hazards in its use, the burden now rests with the gynecologic oncologist who does not use this prophylactic treatment to show cause for its omission.
Supranational identity, democratic attitudes, and political participation: The EU and Moldova

Individuals self-categorize within an international context, and this supranational identity shapes expectations for their own political system. Those individuals in post- Communist countries who believe that their country's primary international orientation should be towards the European Union have a more participatory view of politics and are more politically active. This study develops a social identity explanation of political behavior, and tests the explanation utilizing maximum likelihood and non-parametric matching methods in a 2004 survey of political attitudes in Moldova. Moldova's patch- work of identities, mixed historical legacy, and salience of supranational association make it an excellent case for study. The analysis finds strong support for the effect of supranational identity across a wide range of attitudes and activities.
Automatic diagnosis and location of open-switch fault in brushless DC motor drives using wavelets and neuro-fuzzy systems

The faulty performance of permanent-magnet (PM) brushless dc motor drives is studied under open-switch conditions. The wavelet transform is used to extract diagnostic indices from the current waveform of the motor dc link. An intelligent agent based on adaptive neuro-fuzzy inference systems (ANFIS) is developed to automate the fault identification and location process. ANFIS is trained offline using simulation results under various healthy and faulty conditions obtained from a lumped-parameter, network model. ANFIS testing shows that the system could not only detect the open-switch fault, but also identify the faulty switch. Good agreement between simulation results and measured waveforms confirms the effectiveness of the proposed methodology.
Measurement of diabetes stress in older children and adolescents with type 1 diabetes mellitus.

Objective Studies indicate general psychological stress plays a role in the glycemic control of individuals with type 1 diabetes mellitus (T1DM). Disease-specific rather than general measures may be more closely related to measures of health outcomes. Therefore, measurement of diabetes-related stress is needed to advance knowledge of significant relationships between stress and glycemic control. The objective of this study was to evaluate the psychometric properties of a measure of diabetes-related stress for youth with T1DM. Research design and methods A 65-item diabetes stress questionnaire for youths (DSQY) was previously developed for use with older children and adolescents. The DSQY was completed by 417 youths with T1DM and the results were analyzed to determine the factor structure and psychometric properties of the questionnaire, as well as relationships of diabetes stress with demographic and clinical variables. Results A factor analysis of the DSQY yielded an eight-factor solution with acceptable internal consistencies. Significant relationships were observed between glycemic control and stress related to parents and dietary issues. While age and socioeconomic status were unrelated with DSQY scores, higher stress was associated with longer diabetes duration, female gender, and racial/ethnic minority status. Conclusions The DSQY is a reliable and valid measure for assessment of diabetes-specific stress in youths with T1DM.
Evaluation of Radar Reflectivity-Based Estimates of Water Content in Stratiform Marine Clouds

Abstract The performance of radar reflectivity (Ze)–based relations for retrievals of marine stratiform cloud liquid water content (LWC) is evaluated by comparing liquid water path (LWP) estimates from microwave radiometers with vertically integrated LWC values retrieved from radar measurements. Based on a measurement dataset from a research vessel in the tropical eastern Pacific Ocean, it is shown that reflectivity thresholding allows minimizing of the influence of drizzle drops present in marine stratiform clouds to the extent that LWP estimates from a ground-/shipborne radar can have uncertainties that might be acceptable for different applications. The accuracies of Ze-based retrievals depend on the thresholding level Zet, and they are generally better than a factor of 2 for Zet ≲ −15 dBZ. These accuracies typically improve when Zet is lowered; however, the amount of cloud profiles that pass thresholding diminishes as Zet is decreased from about 50% for a −15-dbZ threshold to only about 10% for a −25-...
Nutrient intake patterns, body mass index, and vitamin levels in patients with rheumatoid arthritis.

Objective. To assess nutrient intakes and vitamin levels in 79 patients with rheumatoid arthritis participating in a trial and to determine whether changes in body mass index were associated with changes in disease activity. Methods. This study evaluated baseline vitamin levels, 1-day dietary intakes, and weight every 3 months for 1 year. Linear regression analysis was used to evaluate the relationship of time to body mass index. Analysis of covariance was used to determine if body mass index, time, or treatment had an effect on disease activity. Results. Deficient vitamin levels and poor nutrient intake patterns were prevalent in the study population. Changes in body mass index over time did not correlate with changes in disease activity. Conclusions. Rheumatoid arthritis patients are at high risk of obesity, abnormal vitamin levels, and poor nutrient intakes. Changes in body mass index failed to correlate with changes in disease activity.
Possibilities for error during communication by neotropical frogs in a complex acoustic environment

Differences in vocalizations promote accurate identification of species during mate choice. The proper- ties of vocalizations vary, however, and overlap in the properties of different species' calls raises the possibility of errors in species identification. A general model of these possibilities is provided by discriminant function analysis (DFA). To illustrate this use of DFA, we consid- er possibilities for error in the classification of advertise- ment calls by Hyla ebraccata in a diverse community of neotropical hylid frogs. The analysis used three features of their calls: duration, dominant frequency, and pulse repetition rate, separately and in combination. These properties are known to be used for mate choice by fe- male H. ebraccata and many other species of frogs. With only one feature, DFA misidentified 12-32% of individ- uals, either by assigning H. ebraccata calls to other spe- cies (missed detections) or by assigning calls of other species to H. ebraccata (false alarms). With two call pa- rameters, DFA committed few or no errors. If the analy- sis included the relative abundances of the different spe- cies, there were even fewer errors. Thus DFA can use as few as two features to identify calls of H. ebraccata al- most without error. The dispersion of the different spe- cies in discriminant-function space was random, not overdispersed as expected, regardless of the call features included in the analysis. The lack of overdispersion might be explained by differences in selection on calls of common and rare species. This application of DFA indi- cates several ways in which understanding the possibili- ties for errors can advance our understanding of the evo- lution of communication in general.
3D CFD Electrochemical and Heat Transfer Model of an Integrated-Planar Solid Oxide Electrolysis Cell

A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in a new novel integrated planar porous-tube supported solid oxide electrolysis cell (SOEC). The model is of several integrated planar cells attached to a ceramic support tube. This design is being evaluated with modeling at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean per-cell area-specific-resistance (ASR) values decrease with increasing current density. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, cathode and anode exchange current density, and contact resistance from the base case are presented. Contour plotsmore » of local electrolyte temperature, current density, and Nernst potential indicated the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Results are discussed for using this design in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal efficiency, cell electrical efficiency, and Gibbs free energy are discussed and reported herein.« less
A Stochastic Framework for Scheduling in Wireless Packet Access Networks

We put forth a unified framework for downlink and uplink scheduling of multiple connections with diverse quality-of-service requirements, where each connection transmits using adaptive modulation and coding over a wireless fading channel. Based on quantized channel state information at the transmitters (Q-CSIT), we derive the information-theoretic optimal downlink and uplink resource allocation/scheduling strategies using tools from convex/nonlinear optimization theory. When the fading statistics are not known a priori, we develop a class of stochastic primal-dual (SPD) algorithms which can dynamically adapt the scheduling policies online. We prove rigorously and confirm by simulations that with affordable complexity, these SPD algorithms asymptotically converge to the optimal scheduling strategies from any initial value.
Nonminimal derivations in unification-based parsing

Shieber's abstract parsing algorithm (Shieber 1992) for unification grammars is an extension of Earley's algorithm (Earley 1970) for context-free grammars to feature structures. In this paper, we show that, under certain conditions, Shieber's algorithm produces what we call a nonminimal derivation: a parse tree which contains additional features that are not in the licensing productions. While Shieber's definition of parse tree allows for such nonminimal derivations, we claim that they should be viewed as invalid. We describe the sources of the nonminimal derivation problem, and propose a precise definition of minimal parse tree, as well as a modification to Shieber's algorithm which ensures minimality, although at some computational cost.
The Adaptive Code Kitchen: Flexible Tools for Dynamic Application Composition

Driven by the increasing componentization of scientific codes, the deployment of high-end system infrastructures such as the grid, and the desire to support high level problem solving primitives, application composition systems have become prevalent in computational science practice. We present the adaptive code kitchen which, as the name connotes, is a loose collection of capabilities to help realize complex adaptive composition scenarios. These include function interception, continuation modification, dynamic process checkpointing and rollback, and runtime recommendation. Using these broad primitives, a computational scientist can specify many 'recipes' of adaptivity as complete control systems around native object codes. Runtime systems support then enables loading and linking of native code components, monitoring of performance indicators, consulting a recommender system for algorithmic decisions, and dynamically updating application components in response to the recommendations. We present the architecture of the adaptive code kitchen and the key enabling technologies with brief mention of the applications that will be investigated henceforth during the course of the project.
Characterization of vasopressin-responsive collecting duct adenylyl cyclases in the mouse

Little is known about collecting duct adenylyl cyclase (AC) isoforms or regulation in the mouse. We performed RT-PCR for AC isoforms 1–9 in microdissected cortical (CCD) and outer medullary (OMCD) and acutely isolated inner medullary (IMCD) collecting duct. All collecting duct regions contained AC3, AC4, and AC6 mRNA, while CCD and OMCD, but not IMCD, also contained AC5 mRNA. Acutely isolated IMCD expressed AC3, AC4, and AC6 proteins by Western blot analysis. The mIMCD3 cell line expressed AC2, AC3, AC4, AC5, and AC6 mRNA; M-1 CCD cells expressed AC2, 3, 4, and 6, while mpkCCD cell lines contained AC3, AC4, and AC6 mRNA. AVP stimulated cAMP accumulation in acutely isolated mouse IMCD; this was reduced by chelation of extracellular calcium (EGTA) and almost completely abolished by blockade of calmodulin (W-7). Blockade of calmodulin kinase with KN-93 or endoplasmic reticulum calcium ATPase (thapsigargin) also reduced the AVP response. A similar inhibitory effect of W-7, KN-93, and thapsigargin was seen on forskolin-stimulated cAMP content in acutely isolated mouse IMCD. These three agents had the same pattern of blockade of AVP- or forskolin-stimulated AC activity in acutely isolated rat IMCD. AVP responsiveness in primary cultures of mouse IMCD was also reduced by W-7, KN-93, and thapsigargin. Small interfering RNA (siRNA) designed to knock down AC3 or AC6 in primary cultured mouse IMCD significantly reduced AVP-stimulated cAMP accumulation. Together, these data are consistent with a role of AC3 and AC6 in the activation of mouse collecting duct by AVP.
Studies on the Tissue Distribution of the Puromycin-Sensitive Enkephalin-Degrading Aminopeptidases

An antiserum generated to the soluble form of the rat brain puromycin-sensitive enkephalin-degrading aminopeptidase was used to determine the tissue distribution of the soluble and membrane-associated forms of this enzyme. All tissues examined contained significant levels of the soluble enzyme form, with this enzyme accounting for greater than 90% of the arylamidase activity in brain, heart, and skeletal muscle. Native gel electrophoresis coupled with activity staining as well as inhibition studies were used to confirm the presence of this enzyme in various tissues. Serum was found not to contain this particular aminopeptidase. In contrast to the results obtained with the soluble enzyme form, brain was the only tissue found to contain the membrane-associated enzyme form. Although all tissues contained membrane-associated aminopeptidase activity only the brain enzyme could be maintained in solution in the absence of detergent. In addition, the brain membrane-associated enzyme could be distinguished from the membrane-associated aminopeptidase activity in other tissues on the basis of its sensitivity to inhibition by puromycin.
A Dynamic Equilibrium Model of International Portfolio Holdings

This paper develops a continuous-time equilibrium model of a two-country exchange economy with heterogeneous agents and nontraded goods. Nontraded goods play the role of state variables that shift the marginal utility of traded goods. This affects prices and generates dynamic hedging demands that explain the well documented home bias puzzle in international equity portfolios. When calibrated to both consumption and production data, the model is able to generate significative home bias in equity portfolios. A new methodology, based on Malliavin calculus, is presented to solve for the portfolio policies along the equilibrium path. This methodology allows one to reduce the determination of equilibrium portfolio holdings to the solution of a linear algebraic system, rather than a partial differential equation.
Notch signaling at a glance

Cell–cell interactions define a quintessential aspect of multicellular development. Metazoan morphogenesis depends on a handful of fundamental, conserved cellular interaction mechanisms, one of which is defined by the Notch signaling pathway. Signals transmitted through the Notch surface receptor have a unique developmental role: Notch signaling links the fate of one cell with that of a cellular neighbor through physical interactions between the Notch receptor and the membrane-bound ligands that are expressed in an apposing cell. The developmental outcome of Notch signals is strictly dependent on the cellular context and can influence differentiation, proliferation and apoptotic cell fates. The Notch pathway is conserved across species (Artavanis-Tsakonas et al., 1999; Bray, 2006; Kopan and Ilagan, 2009). In humans, Notch malfunction has been associated with a diverse range of diseases linked to changes in cell fate and cell proliferation including cancer (Louvi and Artavanis-Tsakonas, 2012). In this Cell Science at a Glance article and the accompanying poster we summarize the molecular biology of Notch signaling, its role in development and its relevance to disease.
Detecting selection in immunoglobulin sequences

The ability to detect selection by analyzing mutation patterns in experimentally derived immunoglobulin (Ig) sequences is a critical part of many studies. Such techniques are useful not only for understanding the response to pathogens, but also to determine the role of antigen-driven selection in autoimmunity, B cell cancers and the diversification of pre-immune repertoires in certain species. Despite its importance, quantifying selection in experimentally derived sequences is fraught with difficulties. The necessary parameters for statistical tests (such as the expected frequency of replacement mutations in the absence of selection) are non-trivial to calculate, and results are not easily interpretable when analyzing more than a handful of sequences. We have developed a web server that implements our previously proposed Focused binomial test for detecting selection. Several features are integrated into the web site in order to facilitate analysis, including V(D)J germline segment identification with IMGT alignment, batch submission of sequences and integration of additional test statistics proposed by other groups. We also implement a Z-score-based statistic that increases the power of detecting selection while maintaining specificity, and further allows for the combined analysis of sequences from different germlines. The tool is freely available at http://clip.med.yale.edu/selection.
Simulation of minimal infrastructure short-range radar networks

Distributed networks of short-range radars offer the potential to observe winds and rainfall at high spatial resolution in volumes of the troposphere that are unobserved by today's long-range weather radars. One class of potential distributed radar network designs includes Off-the-Grid (OTG) weather radar networks. These are short-range radar nodes designed to be deployed as part of an ad-hoc network and to limit their reliance on existing infrastructure. Independence of the wired infrastructure (power or communications) would allow OTG networks to be deployed in specific regions where sensing needs are greatest, such as mountain valleys prone to flash-flooding, geographic regions where the infrastructure is susceptible to failure, and underdeveloped regions lacking urban infrastructure. This paper will present a system model and simulation framework for the design of OTG networks. The model estimates the energy requirements of the three major system functions, sensing, communicating and computing, as well as power generated from the solar panel. The simulation will be used to develop an energy cost function to be used in control decisions.
Mental budgeting versus marginal decision making: training, experience and justification effects on decisions involving sunk costs

Many studies have shown that individuals make economically irrational decisions by using, rather than ignoring, sunk cost information. In this study, the effects of relevant academic training, financial experience and decision justification on investment decisions involving sunk costs were examined. Data on both the process (strategy) and outcome of the decisions were collected. The results indicate that practicing Certified Public Accountants (CPAs), Masters of Business Administration students (MBAs) and undergraduate accounting students perform better than undergraduate psychology students. The level of training, as measured by the number of college courses in managerial accounting, was found to be positively correlated with performance, while the level of experience, as measured by years of financially-related work, was not. Justification was found to improve decisions only for those participants with significant work experience (MBAs and CPAs). Strategies used in this type of decision were examined with the surprising finding that economically rational decisions can be made even if sunk costs are not ignored. Copyright © 2007 John Wiley & Sons, Ltd.
Matching 4.7-Å XRD Spacing in Amelogenin Nanoribbons and Enamel Matrix

The recent discovery of conditions that induce nanoribbon structures of amelogenin protein in vitro raises questions about their role in enamel formation. Nanoribbons of recombinant human full-length amelogenin (rH174) are about 17 nm wide and self-align into parallel bundles; thus, they could act as templates for crystallization of nanofibrous apatite comprising dental enamel. Here we analyzed the secondary structures of nanoribbon amelogenin by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) and tested if the structural motif matches previous data on the organic matrix of enamel. XRD analysis showed that a peak corresponding to 4.7 A is present in nanoribbons of amelogenin. In addition, FTIR analysis showed that amelogenin in the form of nanoribbons was comprised of β-sheets by up to 75%, while amelogenin nanospheres had predominantly random-coil structure. The observation of a 4.7-A XRD spacing confirms the presence of β-sheets and illustrates structural parallels between the...
The “Banana Belt” of the Coastal Regions of Southern Oregon and Northern California

Abstract The coastal regions of southern Oregon and northern California can be considerably warmer than locations to the north and south when air descends the substantial mountain barrier to the east. This paper describes the event of 27 February 1985, during which Brookings, Oregon experienced the highest February temperature ever observed in that state.
catena-Poly[[bis­(μ-5-bromo­pyridine-3-carboxyl­ato-κ2 O:O′)dicopper(II)]-bis­(μ-5-bromo­pyridine-3-carboxyl­ato)-κ3 O,O′:N;κ3 N:O,O′]

The title compound [Cu2(C6H3BrNO2)4]n, forms sheets in the bc plane. The structure features the dinuclear paddle-wheel cage motif common to copper(II) carboxyl­ates. The polymeric structure is achieved through bridging between binuclear units by the pyridyl donors of two of the four carboxyl­ates of the cage. Each cage engages in axial bonding at each copper atom to a pyridyl nitro­gen donor and extends two 5-bromo­pyridine-3-carboxyl­ate groups to bridge to adjacent binuclear sites in the bc plane. Each cage is linked to four adjacent cages in the plane. The intra­dimer Cu⋯Cu distance is 2.6465 (5) A. The remaining 5-bromo­pyridine-3-carboxyl­ate groups project into the inter­lamellar domain and inter­digitate in pairs from each neighboring layer.
Effects of process variables on the yield stress of rheologically modified biomass

Additives that alter the rheology of lignocellulosic biomass suspensions were tested under conditions of variable pH, temperature, and solid concentration. The effects of certain ions, biomass type, and time after the addition of rheological modifier were also examined. Torque and vane rheometry were used to measure the yield stress of samples. It was found that the effectiveness of rheological modifiers depends on pH over a range of 1.5 to 6, biomass type, concentration of certain ions, and time after addition. The time-dependent properties of rheologically modified biomass are sensitive to the type of rheological modifier, and also to mixtures of these additives, which can result in unexpected behavior. We show that time-dependent rheology is not correlated with time-dependent changes of the water-soluble polymer (WSP) in the aqueous environment, such as slow polymer hydration, suggesting that time-dependent changes in the polymer-fiber interaction may play a more significant role.