cssi/SciSciGPT-SciSciNet huggingface dataset:
Data of bromide sorption experiments with woodchips and tracer testing of denitrification beds

Three different woodchip forms were tested for bromide sorption including ground woodchip, unwashed woodchips, and washed woodchips. We used six varying initial bromide concentrations to conduct the bromide sorption experiments with each woodchip form. Data on the initial and equilibrium bromide concentrations, wood mass, and initial and equilibrium solution pH from each of the six experiments are presented. Seven bromide tracer tests were conducted on field-scale denitrification beds. In this paper, data from each of the tracer tests including variation of bromide concentration over time and hydraulic indices of the tracer tests are presented. Interpretation of the data can be found in the research article entitled "Efficacy of bromide tracers for evaluating the hydraulic performance of denitrification beds treating agricultural drainage water" [1].
Profiling microorganisms in whole saliva of children with and without dental caries.

Objectives Dental caries is a highly prevalent infectious disease that causes tooth decay. While no single bacterial species is causative of dental caries, the role of the oral microbiome in oral health and caries is gaining interest. The purpose of this study is to compare the major species present in whole saliva samples from caries-free and caries-active children using the IBIS Universal Biosensor. Material and methods The abundant microbial species in ninety-five whole saliva samples from caries-free and caries-active subjects were characterized using the IBIS Universal Biosensor. Results Twenty-four genera and sixty-five species were detected. Candida and Streptococcus were common across samples, and often the dominant genus. While we did not observe a strong association between the most abundant species and oral health, Bacteroides thetaiotaomicron and Rothia mucilaginosa were enriched in children with active caries; while, Staphylococcus epidermidis was enriched in caries-free children. Conclusions These study trends observed suggest that microbial markers in saliva may serve as predictors of oral health and thus aid in diagnosis and treatments for prevention of caries. Consistent with competitive interactions, we also observed negative associations between Streptococcus pneumoniae and other streptococcal species, Staphylococcus aureus and S. epidermidis, Candida and Neisseria, and Saccharomyces and Streptococcus.
Mother knows best … except when it comes to a diagnosis of preeclampsia: an exploratory study of the convergence between maternal recall of pregnancy-related outcomes and objective medical data.

Objective: This study details the importance of medical professionals accurately explaining a diagnosis of preeclampsia to their patients. Self-report data were compared to medical record data. We ...
Nonclinical Characterization of the Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor Roxadustat, a Novel Treatment of Anemia of Chronic Kidney Disease

Anemia of chronic kidney disease (CKD) is a multifactorial disorder caused by impaired erythropoietin (EPO) production and altered iron homeostasis associated with inflammation. Hypoxia-inducible factor (HIF) is a transcription factor that stimulates erythropoiesis via a coordinated response involving increased EPO production and enhanced iron availability for Hb synthesis. HIF degradation is regulated by HIF-prolyl hydroxylase (HIF-PH) enzymes. We hypothesized that roxadustat, an orally available small-molecule inhibitor of HIF-PH, would increase EPO production and promote erythropoiesis in animal models of anemia. In cells, roxadustat increased both HIF-1α and HIF-2α proteins, leading to an increase in EPO production, even in the presence of EPO-suppressing inflammatory cytokines. Roxadustat administered intermittently to healthy rats and cynomolgus monkeys increased circulating EPO levels, reticulocytes, blood Hb, and hematocrit in a dose-dependent manner. Roxadustat corrected anemia in a rat model of CKD after five-sixth nephrectomy and in a rat model of anemia of inflammation with impaired iron metabolism induced by peptidoglycan-polysaccharide (PG-PS). In the PG-PS model, roxadustat significantly decreased hepatic expression of hepcidin, a hormone responsible for iron sequestration and functional iron deficiency, and increased expression of two genes involved in duodenal iron absorption: divalent metal transporter 1 and duodenal cytochrome b. In conclusion, by activating the HIF pathway, roxadustat increased EPO production, elevated Hb, corrected anemia, and improved iron homeostasis. The coordinated erythropoietic response stimulated by roxadustat, involving both EPO production and mobilization of iron stores, makes this compound a promising treatment of anemia of CKD and anemia associated with functional iron deficiency. SIGNIFICANCE STATEMENT: Roxadustat is a novel orally available small-molecule inhibitor of HIF prolyl hydroxylase enzymes that reversibly stabilizes HIF-α, thus activating transcription of HIF-dependent genes, including EPO and regulators of iron homeostasis. Activation of the HIF pathway by roxadustat induces erythropoiesis in healthy rats and monkeys and corrects experimentally induced anemia in rats. The coordinated erythropoietic response that increases EPO production and mobilizes iron stores makes roxadustat a promising treatment for anemia of chronic kidney disease and anemia associated with functional iron deficiency.
Structure-Rheology-Property relationships in double-percolated Polypropylene/Poly(methyl methacrylate)/Boron nitride polymer composites

Abstract Double-percolated thermally conductive polymer composites comprising of polypropylene (PP), poly (methyl methacrylate) (PMMA), and boron nitride (BN) were successfully produced by melt compounding. The effects of BN platelets sizes on morphology and thermal conductivity (TC) were investigated by mixing three different sizes BN, namely 16, 30 and 180 μm with PP and PMMA. The obtained results demonstrate that for all the sizes, BN platelets were either in the PMMA phase or at the interface, and the ternary composites with high filler loadings showed enhanced TC compared to the corresponding binary systems. It is shown that smaller BN platelets led to finer morphology, which caused more interfaces and consequently more phonon scattering and lower TC of the system. Finally, we show for the first time that there is a direct scaling between particle size, mechanical properties and TC. This work proved the advantage of using double-percolated structure to improve TC of polymer composites and provided a better understanding of the filler size effects on the morphology and TC of ternary systems.
‘Calmly Making Ribbons of the Natural Order’: The Third Policeman, the Culture Industry, and Right Laughter

This article reads The Third Policeman through the lens of Max Horkheimer and Theodor Adorno’s ‘The Culture Industry: Enlightenment as Mass Deception,’ focussing specifically on the distinction they develop between ‘right’ and ‘wrong’ laughter. Through a close reading of key scenes in the novel, it is shown how The Third Policeman offers multiple occasions for resistance to the passive, de-politicising consumption of amusement through a form of 'right laughter' that hinges upon a comic embrace of unpredictability and meaninglessness.To read the article, click Download or View PDF.
The optimal living and survivorship program: Piloting a novel survivorship care model

40Background: Multiple agencies define cancer survivorship as beginning at the time of diagnosis. However, traditional care models deliver “survivorship care” months or years after diagnosis, which...
Active Learning in CNNs via Expected Improvement Maximization

Deep learning models such as Convolutional Neural Networks (CNNs) have demonstrated high levels of effectiveness in a variety of domains, including computer vision and more recently, computational biology. However, training effective models often requires assembling and/or labeling large datasets, which may be prohibitively time-consuming or costly. Pool-based active learning techniques have the potential to mitigate these issues, leveraging models trained on limited data to selectively query unlabeled data points from a pool in an attempt to expedite the learning process. Here we present "Dropout-based Expected IMprOvementS" (DEIMOS), a flexible and computationally-efficient approach to active learning that queries points that are expected to maximize the model's improvement across a representative sample of points. The proposed framework enables us to maintain a prediction covariance matrix capturing model uncertainty, and to dynamically update this matrix in order to generate diverse batches of points in the batch-mode setting. Our active learning results demonstrate that DEIMOS outperforms several existing baselines across multiple regression and classification tasks taken from computer vision and genomics.
Technical Change and Gender Wage Inequality: Long-Run Effects of India's Green Revolution

New technologies can have distributional consequences that narrow or widen existing inequalities. In this paper, I estimate the effect of India’s Green Revolution on the gender wage gap in village labor markets. Widely considered the country’s most important episode of agricultural technical change, productivity gains from the Green Revolution were due largely to the introduction of high-yielding variety seeds (HYVs). Their sensitivity to water conditions advantaged locations with reliable irrigation access, which I exploit by constructing a novel dataset of historical groundwater resources as a source of exogenous variation in Green Revolution adoption. Using data from 1956-1987 in a difference-in-differences framework, I estimate that groundwater-rich districts experienced large and significant increases in HYV adoption, crop revenues, and cropping intensity. These productivity gains affected labor markets, with male wages rising, but female wages declining, jointly raising the male wage premium an average 17 percent. Additionally, census and microdata results show women substituted away from wage work, and increased their time in unpaid own-farm work and home production. These outcomes are most likely driven by the sharp yield gains achieved with wheat HYVs. As a male labor-biased crop, the expansion of wheat production contributed to declines in female wage labor participation. These findings document how new technology shocks can generate winners and losers, and offers an example of productivity growth that exacerbated gender disparities.
Are spatial models advantageous for predicting county-level HIV epidemiology across the United States?

Abstract Predicting human immunodeficiency virus (HIV) epidemiology is vital for achieving public health milestones. Incorporating spatial dependence when data varies by region can often provide better prediction results, at the cost of computational efficiency. However, with the growing number of covariates available that capture the data variability, the benefit of a spatial model could be less crucial. We investigate this conjecture by considering both non-spatial and spatial models for county-level HIV prediction over the US. Due to many counties with zero HIV incidences, we utilize a two-part model, with one part estimating the probability of positive HIV rates and the other estimating HIV rates of counties not classified as zero. Based on our data, the compound of logistic regression and a generalized estimating equation outperforms the candidate models in making predictions. The results suggest that considering spatial correlation for our data is not necessarily advantageous when the purpose is making predictions.
A Pilot Study To Establish an In Vitro Model To Study Premature Intestinal Epithelium and Gut Microbiota Interactions.

Intestinal microbiota has emerged as an important player in the health and disease of preterm infants. The interactions between intestinal flora and epithelium can lead to local injury and systemic diseases. A suitable in vitro cell model is needed to enhance our understanding of these interactions. In this study, we exposed fetal epithelial cell cultures (FHs-74 int cells, human, ATCC CCL 241) to sterile fecal filtrates derived from stool collected from preterm infants at <2 and at 3 to 4 weeks of age. We measured the cytokine levels from the culture media after 4, 24, and 48 h of exposure to the fecal filtrates. We analyzed the 16S rRNA V4 gene data of the fecal samples and transcriptome sequencing (RNA-seq) data from the fetal epithelial cells after 48 h of exposure to the same fecal filtrates. The results showed correlations between inflammatory responses (both cytokine levels and gene expression) and the Proteobacteria-to-Firmicutes ratio and between fecal bacterial genera and epithelial apoptosis-related genes. Our in vitro cell model can be further developed and applied to study how the epithelium responds to different microbial flora from preterm infants. Combining immature epithelial cells and preterm infant stool samples into one model allows us to investigate disease processes in preterm infants in a way that had not been previously reported. IMPORTANCE The gut bacterial flora influences the development of the immune system and long-term health outcomes in preterm infants. Studies of the mechanistic interactions between the gut bacteria and mucosal barrier are limited to clinical observations, animal models, and in vitro cell culture models for this vulnerable population. Most in vitro cell culture models of microbe-host interactions use single organisms or adult origin cell lines. Our study is innovative and significant in that we expose immature epithelial cells derived from fetal tissues to fecal filtrates from eight stool samples from four preterm infants to study the role of intestinal epithelial cells. In addition, we analyzed epithelial gene expression to examine multiple cellular processes simultaneously. This model can be developed into patient-derived two- or three-dimensional cell cultures exposed to their own fecal material to allow better prediction of patient physiological responses to support the growing field of precision medicine.
Intravascular Dual-frequency Ultrasound Transducer Using a Stack Composite

Intravascular sonothrombolysis has attracted much attention due to the safe and effective treatment potential compared to other conventional mechanical thrombectomy and high-dose medication. Meanwhile, multiple frequency sonothrombolysis is known to be more efficient to activate cavitation of micro or nano size contrast agents. Yet, the multiple frequency effects combined with an intravascular device have rarely been studied in the past due to technical limitations in transmitting acoustic pressure output with multiple frequencies from a single small aperture. Therefore, in this study, an intravascular ultrasound transducer with a composite structure is reported, which can operate with the dual-frequency condition for enhancing the cavitation effect of infused contrast agents. Compared with single frequency excitation, the in-vitro test results showed a 34% improvement in the lysis rate when the dual-frequency excitation was applied with the nanodroplets infusion.
COTS-Based Systems (CBS) Functional Density -- A Heuristic for Better CBS Design

The conventional rationale for using COTS (commercial off the shelf) components is that the more a software system is built from COTS products, the lower the cost of initial development. Less understood is that during the long term sustainment phase - from deployment through retirement - the cost of maintenance of a COTS-based system generally increases as the number of COTS products used increases. There exists then a tension between the imperative to maximize the use of COTS components to ease CBS development yet minimize the use of COTS components to ease CBS maintenance. A heuristic called the "CBS Functional Density Rule" is proposed to reconcile these two conflicting views. A corresponding metric for characterizing the "efficiency" of a given CBS design relative to another called the "COTS Functional Density" is then suggested. The paper concludes with suggestions for additional research to further validate the empirical foundations of the proposed heuristic and associated metric.
Reflection and Executive Function: Foundations for Learning and Healthy Development

Executive function (EF) refers to the neurocognitive processes involved in the deliberate, goal-directed modulation of thought, action, and emotion. Individual differences in EF measured in childhood predict key developmental outcomes, and interventions designed to foster the healthy development of EF have the potential to help children at risk for a wide range of difficulties. This article briefly describes a theoretical model of EF and its development, the Iterative Reprocessing model that spans levels of analysis and characterizes self-regulation as the product of a dynamic interaction between top-down (reflective) and bottom-up (reactive) influences.
Sensitivity Analysis of Optical Metrics for Spectral Splitting Photovoltaic Systems: A Case Study

Spectral splitting of sunlight to increase photovoltaic (PV) efficiency beyond the Shockley–Queisser limit has gained interest in recent years. Sensitivity analysis can be a useful tool for system designers to determine how much deviation from ideal conditions can be tolerated for different optical parameters. Understanding the origin of these sensitivities can offer insight into materials and device design. We employ 2-D TCAD simulations to analyze the sensitivity of system performance to two optical parameters: spectral fidelity (the fraction of photons directed to the intended material) and the spatial uniformity of illumination intensity. We analyze a system using crystalline silicon (Si) and cuprous oxide (Cu2O) as absorbers. We find that the spectral fidelity of the light directed to the Si cell has to be greater than 90% for the system to outperform a high-efficiency single-junction Si device. Varying the fidelity of the light directed to the Cu2O cell from 55% to 90% changes system efficiency by less than 10% relative. In some cases, increasing the fidelity of this light reduces system efficiency. We find no significant impact of spatial variation on length scales from 600 μm to 4.8 mm in devices with emitter sheet resistance less than 500 Ω/□.
Analytical Modeling of TCP Clients in Wi-Fi Hot Spot Networks

The channel utilization of 802.11-based wireless local area networks has been studied extensively from an analytical perspective. However, these studies consider wireless networks formed by saturated stations that transmit UDP-like traffic to randomly selected destinations. This model cannot be easily applied to hot spots since: i) the majority of Internet applications are based on the TCP protocol; ii) the TCP traffic is rate-controlled and the TCP flow control mechanisms impede the stations to saturate; and iii) the users’ traffic is either sent towards or received from the access point. This paper is the first to provide an analytical model of the channel utilization in hot spots when there are M users which use TCP connections to download traffic from the Internet. Specifically, in this work we analytically investigate the complex interaction of the TCP flow control mechanisms and MAC collision avoidance techniques in 802.lib-based hot spot networks. We validate our model by means of simulations, and we exploit it to provide thorough reasons of the following counter-intuitive observations: i) the channel utilization is almost independent of the number of TCP connections; ii) on average the access point contends with few users for the channel bandwidth.
East Africa's Gorée: slave trade and slave tourism in Bagamoyo, Tanzania.

A tourist visiting Bagamoyo, Tanzania, today would be hard pressed not to come away with the impression that this idyllic, seaside port was once the centre of the East African slave trade. Local museums, interpretive signposts, and amateur tour guides throughout the town claim that tens of thousands of enslaved Africans were brought to Bagamoyo each year before being shipped off across the Indian Ocean. In 2006, the Tanzanian government applied to UNESCO to have Bagamoyo recognized as the exit point of the Central Slave and Ivory Trade Route that reached as far west as Lake Victoria. This paper investigates this application by assessing claims made to prove Bagamoyo's reputation as a major slave entrepot against archival evidence. Similar to the case made by Phil Curtin in 1995 on H-Net regarding the memorialization of the West African island of Goree, I demonstrate that enslaved Africans did not constitute a significant portion of local exports and that numbers have been highly exaggerated; instead, the ...
Is pelvic obliquity related to degenerative scoliosis

Objective The hypothesis of this study is that pelvic obliquity (PO) is associated with specific patterns of degenerative scoliosis. Methods This study was a retrospective case series of consecutive patients undergoing fusion for lumbar conditions (degenerative scoliosis or spondylolisthesis). The discrepancy in the iliac crest height, coronal L1-S1 endplate angles, distance from L1 coronal bisector to the sacral center, number of degenerative scoliosis curves, and individual curve angulations were measured. Results Limb length discrepancy was present in 87% of patients with a degenerative scoliosis. There were 116 patients with a single curve > 5° and PO > 2 cm. Of the patients with a single curve, the apex of scoliosis was opposite the high iliac crest side in 79% patients. There were 338 patients with a double curve. The apex of scoliosis was opposite the high iliac crest side in 48% of patients. Conclusion There were distinct patterns of limb length discrepancy corresponding to degenerative scoliotic curve morphology. In patients with single degenerative scoliotic curves, PO most commonly appeared to counteract the scoliotic curve and result in an overall decrease in trunk shift. This occurred because the high iliac crest was observed most commonly on the convex side of the scoliotic curve. This effect was not observed in double lumbar degenerative scoliotic curves.
The Physics of Gravitationally Collapsed Objects

For a long time it has been recognized that Einstein’s theory of general relativity is very likely the most elegant theoretical framework in modern physics. However, all conceivable effects predicted by this theory and observable inside our own solar system are largely negligible and could be taken into account by a simple ‘tabulation’ of the correction factors from the traditional Newtonian physics. If these observable effects were found to be so negligible in the entire Universe, the relevance of general relativity, despite its mathematical elegance, would certainly have been very limited. However, it has become more and more clear since the pioneering work of Landau [1], Chandrasekhar [2], Baade and Zwicky [3] that to properly describe the processes occurring at the late stages of evolution of a star after all the sources of its thermo­nuclear energy have been exhausted, a fully relativistic theory of gravity is needed and very large deviations from a Newtonian approach are to be expected. Then the process of gravitational collapse appears to be the natural testing ground where one may probe some of the most novel and unique predictions of Einstein’s theory. From an astrophysical point of view, this process is also of the greatest relevance since it repre­sents energetically, by far the most important part of the life of a star. (See Section 7).
Adaptive production systems

Adaptive production systems are defined and used to illustrate adaptive techniques in production system construction. A learning paradigm is described with in the framework of adaptive production systems, and is applied to a simple rote learning task, a nonsense syllable association and discrimination task, and a serial pattern acquisition task. It is shown that with the appropriate production building mechanism, all three tasks can be solved using similar adaptive production system learning techniques.
Effective field theory during inflation: Reduced density matrix and its quantum master equation

We study the power spectrum of super-Hubble fluctuations of an inflatonlike scalar field, the ``system,'' coupled to another scalar field, the ``environment'' during de Sitter inflation. We obtain the reduced density matrix for the inflaton fluctuations by integrating out the environmental degrees of freedom. These are considered to be massless and conformally coupled to gravity as a proxy to describe degrees of freedom that remain sub-Hubble all throughout inflation. The time evolution of the density matrix is described by a quantum master equation, which describes the decay of the vacuum state, the production of particles and correlated pairs and quantum entanglement between super and sub-Hubble degrees of freedom. The quantum master equation provides a nonperturbative resummation of secular terms from self-energy (loop) corrections to the inflaton fluctuations. In the case studied here these are Sudakov-type double logarithms which result in the decay of the power spectrum of inflaton fluctuations upon horizon crossing with a concomitant violation of scale invariance. The reduced density matrix and its quantum master equation furnish a powerful nonperturbative framework to study the effective field theory of long wavelength fluctuations by tracing short wavelength degrees of freedom.
Terminating decision algorithms optimally

Incomplete decision algorithms can often solve larger problem instances than complete ones. The drawback is that one does not know whether the algorithm will finish soon, later, or never. This paper presents a general decision-theoretic method for optimally terminating such algorithms. The stopping policy is computed based on a prior probability of the answer, a payoff model describing the value that different probability estimates would provide at different times, and the algorithm's run-time distribution. We present a linear-time algorithm for determining the optimal stopping policy given a finite cap on the number of algorithm steps. To increase accuracy, the initial satisfiability probability and the run-time distribution are conditioned on features of the instance. The expectation of the result at each future time step is computed using Bayesian updating. We then extend the framework to settings where no exogenous cap is given on the number of algorithm steps. The method also provides a normative basis for algorithm selection. Finally, our method can be used to terminate and/or select complete algorithms optimally as well.
Management Elements for Interpretation Placard System in Mountain Scenic Resort

Tourism interpretation placard system is an important carrier conveying information about scenic resort, which can not only serve tourists but also benefit the management. At present, lots of problems exist in mountain scenic resorts’ tourism interpretation placard system, which influences the resorts’ images and sustainable development. Considering the requirements for interpreting mountain scenic resorts, this paper probes into the management elements for interpretation placard system: establish interpretation placards’ locations, contents, and ways in display, and advance to improve the interpretations for natural landscapes, form scientific interpretation views, actualize standardization and characterization of tourism interpretation placard system, and strengthen tourists’ safety, with the hope for improving the quality and the utility of constructing mountain scenic resorts’ interpretation placard system.
Combined genetic K-means and radial basis function neural network technique for classifying and predicting soil moisture

A combined technique of genetic k-means and radial basis function neural network (RBFNN) is used in this study to process remote sensing data and classify soil basing on its moisture content. Radial basis function neural network is used for its advantages of rapid training, generality and simplicity over feed-forward backpropagation neural network. The genetic k-means clustering is used to choose the initial radial basis centers and widths for the RBFNN. An attempt is also made to study the performance of the RBFNN with the centers and widths chosen using the classical k-means clustering. The results showed that genetic algorithms give global optimal centers and widths for the RBFNN. The results also indicated that this hybrid technique can be used in soil moisture classification and prediction.
TOWARD A THEORY OF CONSTRAINTS

Grounded in the cybernetic concept of negative explanation, the theory of constraints examines how human systems are kept from solving problems. To identify constraints, therapists must know where to look for them and what to look for. The theory proposes that constraints exist among the levels of a biopsychosocial system, which include biology, person, relationship, family, community, and society. The six metaframeworks of organization, sequences, mind, development, gender, and culture assist constraint identification. Combining the levels and metaframeworks creates a web of constraints, the complexity of which determines how difficult it will be to solve a given problem. The theory of constraint offers an integrative and pragmatic approach to therapy while simultaneously honoring the complexity of human systems.
The cycle of the seminiferous epithelium in humans: a need to revisit?

ABSTRACT: Understanding the dynamics of spermatogenesis is central to clinical andrology or to probing environmental effects on human testes. This review considers what is known about renewal and proliferation of spermatogonia, how germ cells are organized in cellular associations constituting the cycle of the seminiferous epithelium, relative frequencies of cellular associations, durations of the cycle of the seminiferous epithelium and spermatogenesis, and measurement of daily sperm production. Daily sperm production (DSP) per testis tends to decline with advancing age. Regardless of age, there is substantial loss of potential sperm from degeneration of spermatocytes, but not spermatids. DSP per gram testis parenchyma or DSP per testis cannot be predicted on the basis of testis size or age of a man. The review shows why our 1960s data base is neither robust nor precise and suggests how deficiencies might be rectified. New cellular associations should be defined, with none representing >15% of the cycle of the seminiferous epithelium. Then determine when Apale-spermatogonia become committed to proliferate or how many mitotic divisions occur thereafter. Restudy the duration of spermatogenesis because the accepted value might be in error by ∼6 days. Restudying human spermatogenesis will benefit clinicians, toxicologists, and epidemiologists probing testis function by direct evaluations or indirectly via evaluations of quantity and quality of sperm ejaculated. It also will benefit scientists interested in renewal and proliferation of spermatogonia, or a spermatogonium as a prototype stem cell.
Monolithically integrated carbon nanotube bundle field emitters using a double-SOI process

Carbon nanotube (CNT) field emitters offer high energy efficiency and high current density needed for miniature analytical instruments for space exploration. This paper reports design and fabrication of monolithically gate-integrated carbon nanotube bundle field electron emitters using double silicon-on-insulator (SOI) substrates. While gate integration with CNT field emitters has been reported before, this process and its extension (as in manylayered- SOI substrates) allow monolithic integration of multiple electrodes for electron beam shaping to produce a highly compact field emission electron gun. In addition, this process offers improved dimensional precision, and can be used to integrate gates with single CNT bundle or with an array as needed for an application.
Relationship between giant planet frequency and stellar metallicity

We describe results from two independent analyses of the [Fe/H] abundance of stars in two separate planet search programs. For the Keck, AAT and Lick (KAL) planet search program, we determined stellar parameters spectroscopically. Results for the CORALIE and KAL both show a similar steep increase in the fraction of stars with known planets as stellar [Fe/H] increases. This planet metallicity correlation is a key observational constraint on the formation and evolution of giant planets. We rule out changes in velocity precision as the cause of the correlation. By comparing stars with different convection zone depths (along and off the main sequence), we rule out chemical enrichment by accretion as the origin of the correlation. Most known planets have migrated inwards since formation. The end point of migration does not depend on stellar [Fe/H], but it is still possible that migration occurs only above some metallicity threshold. The planet–metallicity correlation is consistent with core-accretion scenarios of giant planet formation and inconsistent with gravitational instability models (unless migration occurs preferentially in metal-rich disks).
Auroral N2(c′41Σu+ → a1Πg emission

Abstract Inspection of recent spectra presented by Sivjee (1983) show evidence of the 0–4 and 0–5 bands of the N 2 ( c ′ 4 1 Σ u + → a 1 Π g ) Gaydon-Herman system. In conjunction with earlier spectra, it is now possible that this band system is a significant auroral component, with an intensity approx. 7% that of the N2 2P system. The absence in aurorae of the potentially far stronger N 2 ( c ′ 4 1 Σ u + → X 1 Π g ) system is discussed. It is that the O 2 ( A 3 Σ u + → X 3 Σ g − ) band system is indiscernible in Sivjee's auroral spectra, under conditio the foreground nightglow is expected to be clearly visible. On the other hand, at least one relatively strong O 2 ( A ′ 3 Δ u → a 1 Δ g ) band appears to be present in these spectra.
Fourier Synthesis of Ocean Scenes

Considerable interest in scene synthesis has focused on fractal techniques such as 1/f noise filtering. However, these techniques produce poor synthetic ocean scenes. A superior technique is presented here that used an empirical sea spectrum model to represent a fully developed sea in nautre. A computer program has been written whereby a user supplies a wind velocity, and a two-dimensional Fourier-domain filter is created whose shape is decribed by the modified Pierson-Moskowitz spectrum. A white-noise image can then be filtered and rendered with a ray-tracing algorithm to produce a realistic ocean scene. Wave motion may be invoked by manipulating teh phase of the Fourier-transormed white-noise image. Several phase-manipulating techniques have been implemented.
On the Mean Value of Multiplicative Functions

Abstract We show a theorem which deduces the existence of the mean value [formula] of a multiplicative arithmetic function ƒ: N → C under weaker conditions of Delange, Elliott, Daboussi, and Indlekofer. The theorem also applied cases which Heppner′s theorem does not cover.
Sodium arsenite inhibits terminal differentiation of murine C3H 10T1/2 preadipocytes.

Abstract Cancer represents an imbalance between cell proliferation and differentiation, two processes that are coordinately and antagonistically regulated. Aberrant cell proliferation is considered to be an important etiological factor in the development of arsenic-induced cancer, suggesting that arsenic also dysregulates differentiation. Based on evidence that arsenic modulates mitogenic events that antagonize the process of differentiation, this study addresses the hypothesis that sodium arsenite inhibits insulin/dexamethasone-induced differentiation of C3H 10T1/2 preadipocytes; it was further postulated that arsenic-treated cells retain mitogenic responsiveness under differentiating conditions. To test this hypothesis, the differentiation capacity of C3H 10T1/2 preadipocytes was examined in control cells and cells treated with sodium arsenite. Differentiation was assessed morphologically and quantified by Oil Red-O staining of accumulated lipids. The effect of long-term arsenic exposure on mitogenic competence was quantified by flow cytometry, [ 3 H]thymidine incorporation, and cell counting under conditions favorable for adipocyte differentiation. Results indicate that arsenic inhibits morphological differentiation of wild-type C3H 10T1/2 preadipocytes. Short-term arsenic exposure inhibits differentiation in a dose-dependent manner, with arsenic concentrations ≥3 μM producing a significant inhibition of dexamethasone/insulin-induced lipid accumulation. Furthermore, arsenic-treated cells exhibit an accentuated response to mitogenic stimulation under differentiating conditions. These data suggest that arsenic exposure results in the inhibition of cellular programming required for terminal differentiation of C3H 10T1/2 preadipocytes and that cells acquire mitogenic hyperresponsiveness. The ability of arsenic to dysregulate the balance between proliferation and differentiation is proposed to be one mechanism by which this metalloid causes cancer in humans.
Constructing security on the U.S.–Mexico border

Abstract This article examines U.S.–Mexico border security in both the pre- and post-September 11th, 2001 periods. It argues for and then employs a constructivist approach to better understand the socio-political context in which the United States has formulated policy solutions for certain defined threats or risks—namely undocumented migration, drugs, and terrorism. It explains how these phenomena are treated as security issues on the border, a process that involves the rhetoric and symbolism of political projects concerned with identity, power, and order. This analysis is accomplished through an evaluation of both policy changes and public discourse. The article contends that, in response to a number of transnational threats, a gradual merging of societal and state security has occurred in both periods. The piece concludes with some thoughts on the place of this approach within border studies and the future of U.S.–Mexico border security.
Color-related differences in the chemical composition of aerosol-laden filters

We examined color-related differences in the chemical composition of ∼6000 aerosol filters collected from 1989 to 1997 at three sampling sites in the North Atlantic Ocean (Barbados, Bermuda, and Izana) operated for the Atmosphere/Ocean Chemistry Experiment (AEROCE). The concentrations of the trace elements (Al, Br, Ca, Cl, Fe, Na, Sb, Sc, Se, V) and two ions, NO3− and SO42−; the activities of 210Pb and 7Be; and the mixing ratios of ozone were compared and contrasted for groups of samples and data matched to the three basic colors of aerosol filters (brown, gray or white). Chemical composition is related to filter color, that is, the brown and gray samples correspond to mineral dust and absorbing aerosol from various pollution sources, respectively, although these substances often are mixed in varying proportions. The white filters are best regarded as indicating the absence or low concentrations of dust or other absorbing aerosols, and they are often indicative of clean marine air. Relationships among atmospheric substances differ significantly in the color-stratified data subsets, and grouping the samples by color provides unique insight into the relationships among mineral dust, pollution aerosol, and other substances over the North Atlantic.
Tenure denied! not ready for promotion! no merit pay increase! poor Leonardo da Vinci!

Abstract Most academic institutions convey to faculty that they must have a clearly identified single or dual stream of research. Such a standard inhibits expertise. It stifles creativity and innovation and results in faculty unable to deal effectively with a broad range of doctoral students. People like Leonardo da Vinci, and other outstanding experts, fall outside of such a standard and, in today's academic world, would be denied promotion and tenure. Such artificial standards forcing all faculties to behave in the same way must be set aside.
A Cost-Benefit Analysis of Ocean Mineral Resource Development: The Case of Manganese Nodules

N recent years, both popular magazines and scholarly journals have, in increasing numbers, heralded the imminent opening up of the "inexhaustible treasures of the oceans," leading some investment advisory services to conclude that ocean mining will be "the growth industry of the 1970's." At the same time, committees of the United Nations are studying the implications of ocean mineral exploitation for the underdeveloped nations, fearing the impending loss of major export sales and hoping to arrive at a "law of the sea" which protects these nations' presumed "natural right" to a basic inheritance of mankind. Is this optimism justified? And are there externalities connected with these developments of sufficient value that a case can be made for government inducements to growth? The present paper attempts to answer these questions by applying cost-benefit analysis to the most promising untapped ocean mineral resource, manganese nodules.
Conjugate gradient methods in optimization

This paper attempts to survey our knowledge, and the practical scope of our use of, the method of conjugate gradients and its close relatives in the numerical solution of problems of quadratic and nonquadratic optimization.
Amino-terminal region of poliovirus 2C protein is sufficient for membrane binding

Abstract The poliovirus-encoded, membrane associated polypeptide 2C is required for viral replication. We have previously established that, while the 2C protein lacks a defined membrane binding domain, the N-terminal region containing a putative amphipathic helix plays an important role in membrane binding both in vivo and in vitro. In order to determine whether the N-terminal region is sufficient for membrane binding, we have made fusion constructs between this region of 2C (amino acids 1–72 and 1–88) and a soluble protein, chloramphenicol acetyltransferase (CAT). The ability of CAT and the fusion polypeptides to bind to membranes was examined by in vitro translation in the presence of microsomal membrane. While CAT was found in the soluble fraction, both 2C/CAT fusion constructs (1–72/CAT and 1–88/CAT) were membrane associated, suggesting that the N-terminal region of 2C was sufficient to impart membrane binding. To confirm these results in vivo, CAT, 1–72/CAT, and 1–88/CAT were expressed in HeLa cells and their localization was examined using indirect immunofluorescence. Results presented here demonstrate that, while CAT is expressed throughout the cell, 1–72/CAT and 1–88/CAT constructs are capable of localizing to the endoplasmic reticulum (ER) area in transfected cells in the absence of other poliovirus proteins. These results suggest that the first 72 amino acids of 2C contain a membrane binding domain that is capable of targeting soluble proteins to the ER region of the cell.
A BAND-RATIO TECHNIQUE FOR DETERMINING TEMPERATURES AND CONCENTRATIONS OF HOT COMBUSTION GASES FROM INFRARED-EMISSION SPECTRA,

An infrared-band-ratio technique (BRT) has been developed by which infrared emission spectra from various bands of H2O and CO2 in the 1-μ to 3.5-μ spectral region are used to determine the temperature and concentration ratio [CO2]/[H2O] of hot gases. BRT is based on the observation that the integrated intensities of various H2O and CO2 bands are temperature dependent and that emission in the 2.7-μ spectral region is due to both H2O and CO2. Although BRT is applicable to any molecule, the working curves have been obtained only for H2O and CO2, as an example of the method. The original technique is extended to include emission from a continuum source; moreover, working curves are given for small carbon particles in the hot-gas sample. The carbon work is based on a specific model for the absorption coefficient as a function of temperature and wavelength. The technique has been applied to hot-gas systems, where the temperatures and concentrations are known from an independent experiment, and the agreement with those values found by BRT is very good.
Volatile retention during freeze drying of protein solutions

Abstract Retention of 14 C-labeled 2-propanol was studied in freeze-dried systems containing either bovine serum albumin (BSA) or pepsin. Retention during freeze drying varied with: initial concentration of solids and 2-propanol, rate of freezing and sample thickness. Heat denaturation of the proteins did not significantly affect the volatile retention. When freeze-dried BSA was rehumidified, volatile retention dropped to a new level which depended on the final water content. Heating the freeze-dried BSA systems in vacuum had no effect on the 2-propanol retention. The results are indicative of structurally dependent retention and can be mainly interpreted by the “microregions” theory of volatile retention.
Select Inflammasome Assembly

Some pairs of interacting proteins have homologous domains in other species that are fused together to form a single multidomain protein. This observation has been successfully exploited by various computational methods that predict inter actions between different protein domains ( 1 , 2 ). On page 481 in this issue, Shenoy et al. ( 3 ) use a similar approach to identify a protein in macrophages that selectively induces the assembly of a large multiprotein complex called the inflammasome. There are distinct types of inflammasomes, differentiated by their protein constituents, activators, and effectors. What has not been clear is how the assembly of these large multiprotein structures is controlled.
Eocene and Oligocene volcanism at Mount Petras, Marie Byrd Land: implications for middle Cenozoic ice sheet reconstructions in West Antarctica

Evidence for one late Eocene and four middle Oligocene eruptions of Mount Petras, Marie Byrd Land provides new insights into reconstructions of middle Tertiary ice sheet configurations, surface topography, and volcanism in West Antarctica. The interpretation presented here of the volcanic record at Mount Petras, based on detailed analyses of lithofacies, petrography, 40Ar/39Ar geochronology, and geochemistry, is significantly different from previous interpretations based on reconnaissance studies. A massive, 25 m thick, mugearite lava near the summit of Mount Petras is 40Ar/39Ar dated to 36.11 ± 0.22 Ma (2 σ uncertainty), indicating an onset of Cenozoic alkaline volcanism in the Marie Byrd Land Volcanic Province in latest Eocene time. Middle Oligocene (29-27 Ma) hawaiite volcaniclastic lithofacies at Mount Petras are interpreted as products of mixed magmatic (Strombolian style) and phreatomagmatic (Surtseyan style) subaerial eruptions. The four hawaiite outcrop areas exhibit characteristics of near-vent tuff cone environments. The near-vent deposits are located at different elevations and positions on Mount Petras and suggest four separate eruptive centres, with eruptions dated to between 28.59 ± 0.22 Ma and 27.18 ± 0.23 Ma. The mixed Surtseyan and Strombolian eruptions imply local or intermittent contact with external water, which we infer was derived from melting of a thin, local ice cap or ice and snow on slopes. The 29-27 Ma volcanic deposits at Mount Petras provide the oldest terrestrial evidence for glacial ice in Marie Byrd Land. The 29-27 Ma tuff cone deposits overlie an erosional unconformity, with > 400 m of topographic relief. The relatively high relief pre-volcanic environment is suggestive of ongoing erosion and is inconsistent with previous interpretations of a regional, low relief, early Cenozoic West Antarctic Erosion Surface.