cssi/SciSciGPT-SciSciNet huggingface dataset:
Associations between Escherichia coli O157 shedding and the faecal microbiota of dairy cows.

Aims Dairy cattle shed pathogenic Escherichia coli O157 (O157) in faeces, playing a role in human exposure. We aimed to measure faecal microbial communities in early lactation dairy cattle, and model outcomes with O157 shedding metrics. Methods and results Daily faecal samples were collected from 40 cattle on two Colorado dairies for five consecutive days, and characterized for O157. 16S rRNA gene sequencing was used to measure sample-level microbial communities. Alpha-diversity metrics were associated with O157 outcomes via regression modelling, adjusting for confounders. Differential abundance of taxa were identified between O157(+) and O157(-) samples and between shedding days of individuals, using matched Wilcoxon rank-sum tests, zero-inflated Gaussian (ZIG) regression and negative binomial regression. After removing an outlier, multi-day and intermittently shedding cows had lower average richness compared to those that never shed. ZIG modelling revealed Bacillus coagulans to be more abundant in O157(-) samples, while Moryella were more abundant in O157(+) samples. Negative binomial models and Wilcoxon tests revealed no differentially abundant taxa between O157(+) vs O157(-) samples, or between shedding days of individuals. Conclusions Microbial diversity and some taxa may be influenced by or affect O157 shedding by dairy cattle. Significance and impact of the study If future work corroborates these findings, dairy cow microbial community changes may be used to guide on-farm strategies that mitigate O157 dissemination, protecting the human food chain.
Scaling the Mars Oxygen ISRU experiment (MOXIE) for mars sample return

Space exploration has always faced serious economic challenges corresponding to the huge cost factors that accompany the mass being launched. This issue is a challenge for all previous and upcoming Martian missions, which increases the importance of In-Situ Resource Utilization (ISRU) technologies for future missions. One ISRU technology is being demonstrated by MOXIE, the Mars Oxygen ISRU Experiment. It is being developed by MIT and NASA/JPL as a payload on the Mars 2020 rover to transform the CO2 that makes up 96% of the Martian atmosphere into O 2 using solid oxide electrolysis (SOE). This paper proposes ISRU-produced O 2 to be used as an oxidizer of the propellant for the Mars Ascent Vehicle (MAV) in a Mars Sample Return (MSR) mission or a Human Mars Mission. However, in order to support these missions, the current MOXIE design must be scaled up. This research involves expanding MOXIE to support the mass, volume, and power budget requirements of a potential SpaceX Red Dragon MSR mission, and runs several SimSitu™ tests and simulations on the new modeled system to ensure robust controls and performance on Mars. The research analysis shows the feasibility of supporting the Red Dragon's Mars Ascent Vehicle (MAV) using one stack of 18 expanded MOXIE cells consuming around 404 Watts of power. The expanded system would also require a scaled up orbiting scroll compressor with a mass of around 18 kg occupying a volume of ∼3954 cc. This pump would consume 789 Watts of power. This finding can significantly reduce the financial and complexity aspects of this mission and other similar missions by reducing the launch mass. Thus, this research helps emphasize the feasibility and importance of ISRU technologies in the upcoming Martian missions proposed by NASA and SpaceX.
Efficient Evaluation Techniques for Topological Predicates on Complex Regions

Topological predicates between spatial objects have for a long time been a focus of intensive research in a number of diverse disciplines. In the context of spatial databases and geographical information systems, they support the construction of suitable query languages for spatial data retrieval and analysis. Whereas to a large extent conceptual aspects of topological predicates have been emphasized, the development of efficient evaluation techniques for them has been rather neglected. Recently, the design of topological predicates for different combinations of complex spatial data types has led to a large increase of their numbers and accentuated the need for their efficient implementation. The goal of this paper is to develop efficient implementation techniques for them within the framework of the spatial algebra SPAL2D.
Ultrafast Charge Separation in Two-Dimensional CsPbBr3 Perovskite Nanoplatelets.

Two-dimensional (2D) cesium lead halide perovskite colloidal nanoplatelets show sharper excitonic absorption/emission peaks and larger absorption cross section in comparison to bulk materials and q...
The Range and Reproducibility of the Liver Frailty Index.

The Liver Frailty Index (LFI), composed of 3 performance-based tests (grip strength, chair stands, and balance), is a tool specifically developed in patients with cirrhosis to objectively measure physical function, a critical determinant of health outcomes. We aimed to (1) determine the range of LFI scores in adults with chronic liver disease but without cirrhosis, (2) determine the range of LFI scores in adults without known liver disease, and (3) evaluate reproducibility of the LFI in adults with cirrhosis listed for liver transplantation. Intraclass correlation coefficient (ICC) assessed interrater reliability of the LFI. Included were 91 adults with chronic liver disease, 109 adults without known liver disease, and 166 adults with cirrhosis with median Model for End-Stage Liver Disease-sodium of 16. Median (interquartile range) LFI was 3.6 (3.1-4.1) in adults with cirrhosis, 3.1 (2.5-3.7) in adults with chronic liver disease but not cirrhosis, and 2.7 (2.2-3.2) in adults without liver disease (P < 0.001). Using established LFI cutoffs for robust, prefrail, and frail categories, adults with cirrhosis or chronic liver disease were less likely to be robust (29% versus 53% versus 77%) and more likely to be prefrail (57% versus 42% versus 22%) or frail (14% versus 5% versus 1%) when compared with adults without liver disease (P < 0.001). The LFI had excellent reliability with ICC of 0.93 (95% confidence interval, 0.91-0.95). In conclusion, the LFI has external validity in noncirrhotic populations and is highly reproducible among different raters. This objective assessment tool can be implemented in outpatient clinical practice or research to operationalize the concept of physical frailty.
Developing global champions: Why national oil companies expand abroad

National oil companies (NOCs) have invested hundreds of billions of dollars in foreign oil and gas assets. Why have some governments increased their NOC outward investments, while others have not? I argue that domestic structures can influence a government's calculus that potential benefits, such as added revenues and fuel supply, outweigh potential costs, such as information asymmetries and inefficiencies associated with NOCs. Nationally, partisan competition limits democratic tolerance for failures by NOCs. Bureaucratically, overlapping authority in energy policy undermines coherent NOC governance. Based on investments by NOCs hailing from 79 countries, 2000-2013, I find robust evidence for the national hypothesis.
Automated Reasoning for the Synthesis and Analysis of Biological Programs

Cellular decision-making arises as the output of biochemical information processing, as complex cascades of molecular interactions are triggered by input stimuli. Deciphering critical interactions and how they are organised into biological programs is a huge challenge, compounded by the difficulty of manually navigating alternative hypotheses consistent with observed behaviour. Against this backdrop, automated reasoning is a powerful methodology to tackle biological complexity and derive explanations of behaviour that are provably consistent with experimental evidence. We present a reasoning framework that permits the synthesis and analysis of a set of dynamic biological interaction networks. Employing methods based on Satisfiability Modulo Theories (SMT), we encode experimental observations as specifications of expected dynamics, and synthesise networks consistent with these constraints. Predictions of untested behaviour are generated based on all consistent models, without requiring time-consuming simulation or state space exploration, and the method can be used to identify additional components, topological ‘switches’ that allow cell state changes, and to predict gene-level dynamics. We show the reader how to utilise this reasoning framework to encode and explore rich queries for their biological system of choice.
Medical Imaging Modalities and Protocols

Abstract To capture vascular motions and deformations, proper medical imaging modalities and protocols must be used. This chapter provides a brief overview of X-ray, computed tomography (CT), ultrasound, and magnetic resonance imaging and explains the types of anatomies and vascular motions each can capture. Contrast agents, imaging risks, and image quality trade-offs are discussed, with special attention to resolution, signal-to-noise, and radiation exposure. Specific approaches to capture motions induced by cardiac pulsatility, respiration, and musculoskeletal motion are presented. An example CT angiography protocol to capture cardiac and respiratory motion of the thoracic aorta is provided, along with a list of some common patient recruitment and imaging challenges.
Promising Truths, in Fiction & Teaching: Sincerity

In this essay, Jarvie makes the case for teaching as a sincere act. By that, he does not mean the conventional notion of operating without “pretense, deceit, or hypocrisy” (OED), but instead a more radical uptake drawn from literature—fiction (e.g., Egan, 2010; Eggers, 2001; Wallace, 2001)—and literary theory (Kelly, 2016) that understands the concept as “always contaminated internally by the threat of manipulating the other…this sincerity depends not on purity but on trust and faith” (Kelly, 2016, p. 201). Such a sincerity offers educators ways of teaching hopefully, bringing forth themselves in conversation with students. It offers a way of rethinking teaching as primarily and problematically a manipulative and impositional act, a mode of imagining pedagogy beyond the dichotomy between oppressive transmission pedagogies and liberatory critical ones. Jarvie suggests that if we’re going to humanize (Paris & Winn, 2013) our work as educators and scholars of education, a renewed theorizing that affirms the role of the teacher as relationally important, as having something to offer through the communication of their selves, can enrich the work of teaching—as an extension of teachers’ lives, as creative and communal, compelling, complex, and deeply personal work—in ways that prove fruitful for both teachers and students.
System-Level Framework for Logic Obfuscation with Quantified Metrics for Evaluation

Logic obfuscation techniques are used to deter intellectual property piracy, reverse engineering, and counterfeiting threats in the design and manufacturing of integrated circuits. However, obfuscation can be reverse-engineered in a variety of ways, there has been little effort in measuring the effectiveness of different obfuscation techniques using uniform security and overhead metrics, and only limited investigations on the effect of combining multiple methods on the same die. This paper presents MIRAGE, a system-level end-to-end framework for integrated circuit obfuscation. MIRAGE includes a front-end design space exploration tool that selects an appropriate combination of obfuscation techniques for a given circuit, a netlist manipulation application programming interface to apply the obfuscation, and a back-end analysis tool that evaluates the obfuscation strength in terms of attack resiliency time as well as area, power, and timing overhead. The effectiveness of the proposed framework is illustrated on benchmarks from ISCAS and cores from an open-source system-on-chip test platform, thus extending the analysis to practical circuits with more than 100k gates. MIRAGE utilizes 1,242 circuit configurations to evaluate 6 obfuscation methods in terms of the attack resiliency time and the obfuscation overheads such as area, power, and timing.
Bridging the Gap Between Green Self-Perception and Intentional Behaviors: Mediating Role of Ad-Brand Congruency

This study draws on social identity and congruity theories to examine the effect of green self-perception on intentional behaviors. Also, this study tests the role of ad-brand congruency in bridging between green self-perception (i.e., perceived consumer effectiveness) and intentional behaviors (i.e., share and purchase intentions). A total of 612 college students attending a large university in the US was used for the data analysis. A structural equation modeling was used for final data analysis. The results provide support for the effect of green self-perception on ad-brand congruency and intentional behaviors. Findings revealed that the direct effect of ad-brand congruency was stronger than the direct effect of green self-perception on intentional behaviors. The mediating role of ad-brand congruency was statistically significant in the relationship. The results provide support for the importance of matching the CSR advertising appeals and the brand image in the social media context where green-minded consumers encounter advertisements stimulating green consumption.
Sorting Parity Encodings by Reusing Variables

Parity reasoning is challenging for CDCL solvers: Refuting a formula consisting of two contradictory, differently ordered parity constraints of modest size is hard. Two alternative methods can solve these reordered parity formulas efficiently: binary decision diagrams and Gaussian Elimination (which requires detection of the parity constraints). Yet, implementations of these techniques either lack support of proof logging or introduce many extension variables.
International Development Buzzwords: Understanding Their Use Among Donors, NGOs, and Academics

Scholars and practitioners of international development often note the use of ‘development buzzwords’: terms that represent hot topics in the field. Buzzwords characterise a development issue and i...
The introduction of an Oracle in a simple finance inspired dynamic system leads to instability

The rising of the Computational Oracles in our society justifies the effort to study the Oracle Theory and its application. We will introduce a finance based model of differential equations, which is able to model the introduction of an Oracle in a Game. Analyzing this model we will find surprising results connected with Economic Crysis and Oracle Supremacy.
Pavement treatment type influences visitor experiences related to vehicular road sound in Death Valley National Park

In many parks and protected areas around the globe, reducing human-caused sounds is a critical component to providing quality visitor experiences. However, very little research examines the effect ...
MinerRay: semantics-aware analysis for ever-evolving cryptojacking detection

Recent advances in web technology have made in-browser crypto-mining a viable funding model. However, these services have been abused to launch large-scale cryptojacking attacks to secretly mine cryptocurrency in browsers. To detect them, various signature-based or runtime feature-based methods have been proposed. However, they can be imprecise or easily circumvented. To this end, we propose MinerRay, a generic scheme to detect malicious in-browser cryptominers. Instead of leveraging unreliable external patterns, MinerRay infers the essence of cryptomining behaviors that differentiate mining from common browser activities in both WebAssembly and JavaScript contexts. Additionally, to detect stealthy mining activities without user consents, MinerRay checks if the miner can only be instantiated from user actions. MinerRay was evaluated on over 1 million websites. It detected cryptominers on 901 websites, where 885 secretly start mining without user consent. Besides, we compared MinerRay with five state-of-the-art signature-based or behavior-based cryptominer detectors (MineSweeper, CMTracker, Outguard, No Coin, and minerBlock). We observed that emerging miners with new signatures or new services were detected by MinerRay but missed by others. The results show that our proposed technique is effective and robust in detecting evolving cryptominers, yielding more true positives, and fewer errors.
Approximated Dynamic Trait Models for Heterogeneous Multi-Robot Teams

To realize effective heterogeneous multi-agent teams, we must be able to leverage individual agents’ relative strengths. Recent work has addressed this challenge by introducing trait-based task assignment approaches that exploit the agents’ relative advantages. These approaches, however, assume that the agents’ traits remain static. Indeed, in real-world scenarios, traits are likely to vary as agents execute tasks. In this paper, we present a transformation-based modeling framework to bridge the gap between state-of-the-art task assignment algorithms and the reality of dynamic traits. We define a transformation as a function that approximates dynamic traits with static traits based on a specific statistical measure. We define different candidate transformations, investigate their effects on different dynamic trait models, and the resulting task performance. Further, we propose a variance-based transformation as a general solution that approximates a variety of dynamic models, eliminating the need for hand specification. Finally, we demonstrate the benefits of reasoning about dynamic traits both in simulation and in a physical experiment involving the game of capture-the-flag.
EDA and Quantum Computing: The key role of Quantum Circuits

Quantum computing (QC) is fast emerging as a potential disruptive technology that can upend some businesses in the short-term and many enterprises in the long run. Electronic Design Automation (EDA) is uniquely positioned to not only benefit from quantum computing technologies but can also impact the pace of development of that technology. Quantum circuits will play a key role in driving the synergy between quantum and EDA. Much like standard cell libraries became the most important abstraction between CMOS technology and most EDA tooling and spawned four decades of EDA innovation and designer productivity, quantum circuits can unleash a similar streak of innovation in quantum computing.
Parliamentary Daydreams in Belarus: When the Rubber-Stamp Really is Just a Rubber-Stamp

As social scientists and political observers, we tend to have a bias towards analyzing events when they produce unusual results or have outcomes that interact dynamically with other social and political processes and institutions. Assigning importance to a given subject of interest is a natural thing, and reassessing under-appreciated political institutions is a particular concern of many comparative political scientists. Scholarship on how authoritarian parliaments can ‘matter’ in different ways grows every year – my own ongoing dissertation research very much so included. So, what do we do when the rubber-stamp really does seem to be a rubber-stamp? We explore the Belarusian case here.
Decision-Making for Emergent Vascular Access

Establishing emergent vascular access is a complicated process, including many different considerations. Providers must consider multiple aspects of patient care, including the need for vascular access, comorbid conditions, advance directives, and the likely clinical course for patients following the initial vascular access attempt. Patients undergoing emergent intervention, evaluation, and treatment require an individualized approach to establishing vascular access, considering myriad factors derived from the patient’s unique presentation as well as the provider’s own subjective experience, the physical environment in which care is provided, understanding of the vascular access process, and the provider’s ability to complete the task at hand. This chapter describes an approach that will help providers to tailor their decision-making process for each patient requiring emergent vascular access rather than relying upon a strictly algorithmic approach.
Hosting a Pipeline of K-12 Robotics Competitions at a College of Engineering – A Review of Benefits and Challenges

This paper describes a pipeline of K-12 robotics challenges, which not only excites and engages elementary through high school students but also provides valuable educational experiences to engineering undergraduate and graduate students from Texas Tech University through formal class work, volunteer opportunities, and engagement in student organizations. It describes the benefits of the robotics programs seen by the participants, school teachers, undergraduate and graduate students, and university faculty as well as struggles and pitfalls experienced.
The Hydronium Ion

Naked protons cannot exist in aqueous solution. Even when one writes (1) one knows that the H+(aq) is a representation of a significantly more complicated moiety (or, to be more precise, set of moieties). The simplest representation of H+(aq) is the hydronium ion (sometimes also referred to as the oxonium ion or the hydroxonium ion), H3O+(aq), but this is just the first in a series the next few members of which are H5O2+, H7O3+, H9O4+, and in summary (H2O)nH3O+, the hydrated hydronium ions (Fig. 1). Keywords: hydronium; oxonium; ion; cation
Induction of human B cell differentiation by Fc region activators. I. Identification of an active tetrapeptide.

Addition of pFc' fragments, composed of residues 334 to 446 in the Fc region of human IgG1, to cultures of human peripheral blood mononuclear cells resulted in the induction of Ig-secreting cells (ISC). Intact IgG1 and F(ab')2 fragments were inactive. The synthetic peptide p23, representing residues 335 to 357, retained the ISC-inducing property of pFc' fragments. The ISC response to p23 exhibited the isotype pattern IgMSC > IgGSC ≥ IgASC. Results from cell depletion experiments revealed that the B cell response to p23 was T cell dependent but relatively monocyte independent. Cell proliferation was not increased in p23-stimulated PBMC cultures. Overlapping synthetic peptides based on the sequence of p23 were used to localize the active site in this molecule. These studies revealed that LPPSR (residues 351 to 355) was the sequence responsible for the ISC-inducing property of p23; however, expression of activity by this pentapeptide sequence could be dampened by N-flanking sequences. Finally, residue-deleted analogs of LPPSR were used to determine that LPPS was the minimum sequence retaining activity. Collectively, these data suggest that the fragmentation of IgG results in the expression of a tetrapeptide sequence with lymphocyte-stimulating properties.
Software Tools and the User Software Engineering Project

Software tools are becoming an increasingly important aspect of systematic methods for software development. This paper describes some general properties of tools, showing how they fit within an engineering approach to software development. Then the use and development of tools within the context of the User Software Engineering (USE) project is described. The paper concludes with some cautionary notes about the nature and use of software tools.
Physiological mechanisms used by fish to cope with salinity stress

ABSTRACT Salinity represents a critical environmental factor for all aquatic organisms, including fishes. Environments of stable salinity are inhabited by stenohaline fishes having narrow salinity tolerance ranges. Environments of variable salinity are inhabited by euryhaline fishes having wide salinity tolerance ranges. Euryhaline fishes harbor mechanisms that control dynamic changes in osmoregulatory strategy from active salt absorption to salt secretion and from water excretion to water retention. These mechanisms of dynamic control of osmoregulatory strategy include the ability to perceive changes in environmental salinity that perturb body water and salt homeostasis (osmosensing), signaling networks that encode information about the direction and magnitude of salinity change, and epithelial transport and permeability effectors. These mechanisms of euryhalinity likely arose by mosaic evolution involving ancestral and derived protein functions. Most proteins necessary for euryhalinity are also critical for other biological functions and are preserved even in stenohaline fish. Only a few proteins have evolved functions specific to euryhaline fish and they may vary in different fish taxa because of multiple independent phylogenetic origins of euryhalinity in fish. Moreover, proteins involved in combinatorial osmosensing are likely interchangeable. Most euryhaline fishes have an upper salinity tolerance limit of approximately 2× seawater (60 g kg −1 ). However, some species tolerate up to 130 g kg −1 salinity and they may be able to do so by switching their adaptive strategy when the salinity exceeds 60 g kg −1 . The superior salinity stress tolerance of euryhaline fishes represents an evolutionary advantage favoring their expansion and adaptive radiation in a climate of rapidly changing and pulsatory fluctuating salinity. Because such a climate scenario has been predicted, it is intriguing to mechanistically understand euryhalinity and how this complex physiological phenotype evolves under high selection pressure.
An investigation on parasitic couplings and feedback loops in the CMOS circuits

Two major problems in network partitioning are investigated: the parasitic coupling capacitances between the partitioned subcircuits, and the feedback loops. The coupling capacitance effect is shown to be negligible if state transitions in the neighboring subcircuits do not occur simultaneously. A decoupling criterion is developed to decide whether the coupling between the subcircuits is negligible. A loop-merging algorithm is developed to handle feedback in loops such a manner that the network topology is described by a unidirectional signal path graph, which makes it possible for a single-sweep Gauss-Seidel relaxation. Moreover, an event-driven algorithm is proposed to take advantage of the hierarchical loop structure resulting from the merge algorithm. >
Role of nutrition in the prevention of toxemia

Toxemia of pregnancy is called the disease of theories because over decades of research numerous causes have been proposed but none proved. Although many nutritional factors have been suggested as playing a causal role in the etiology of toxemia mortality from this disease has not varied over time or between circumstances as one would expect a nutritional disease to do. This does not mean that there is no nutritional influence but it does mean that the available evidence does not show that nutrition makes a major difference in maternal mortality from toxemia of pregnancy. (authors)
A Child with ADHD: Convergences of Rorschach Data and Case Material

The Rorschach protocol and psychotherapy of a 7 year-old boy with severe ADHD symptomatology were studied in conjunction with one another. Both arenas place a premium on affect tolerance and expression. On the Rorschach, he displayed a constricted record on achromatic cards and a chaotic record on chromatic cards. This pattern was replicated many times over the course of his subsequent dynamically-oriented treatment. Both patterns were explained as an attempt to either simplify or deaden complex/ambiguous stimuli, with inner and outer tumult as the result when the emotional demands of a given situation could not be subdued in that manner. This work was supported in part by the National Institute on Deafness and Other Communication Disorders Grant # DC 04992-02 awarded to Hilary Gomes. Ph.D., and by a PSC-CUNY Award given to Steve Tuber, Ph.D. The authors gratefully acknowledge the enormous help they received on this project from Professor Gomes and Virginia Wolfson.
Human and canine fucosidosis: a comparative lectin histochemistry study

Selected formalin-fixed, paraffin-embedded tissues of human and canine fucosidosis were stained with nine different lectins. Neurons, splenic sinusoidal cells, hepatic Kupffer cells, tissue macrophages, and capillary endothelium from human patients with fucosidosis stained intensely withUlex europaeus agglutinin-I (UEA-I), but the same cells were unstained in tissues from canine fucosidosis. Since UEA-I specifically binds to terminal fucose residues, and fucose-rich undegraded metabolites are stored in affected cells of both human and canine fucosidosis, the variable lectin staining pattern demonstrates an unexpected species-specific histochemical variability. This finding highlights the fact that although both species have decreased fucosidase activity, the precursor substrates, undegraded stored metabolites, and particular cells affected by this enzyme deficiency are different.
Developing New Cast Austenitic Stainless Steels With Improved High-Temperature Creep Resistance

Oak Ridge National Laboratory (ORNL) and Caterpillar have recently developed a new cast austenitic stainless steel, CF8C-Plus, for a wide range of high-temperature applications, including diesel exhaust components and turbine casings. The creep-rupture life of the new CF8C-Plus is over ten times greater than that of the standard cast CF8C stainless steel, and the creep-strength is about double. Another variant, CF8C-Plus Cu/W has been developed with even more creep strength at 750–850°C. The creep-strength of these new cast austenitic stainless steels is close to that of Ni-based superalloys like 617. CF8C-Plus steel was developed in about 1.5 years using an “engineered microstructure” alloy development approach, which produces creep resistance based on formation of stable nano-carbides (NbC) and prevention of deleterious intermetallics (sigma, Laves). CF8C-Plus steel won a 2003 R&D 100 Award, and to date, over 32,000 lb have been produced in various commercial component trials. The current commercialization status of the alloy is summarized.Copyright © 2007 by Caterpillar, Inc.
Precipitation of nanocomposite particles from a multi-component, rapidly expanding supercritical solution

Abstract Composite micro- and nanoscale particles were precipitated from rapidly expanding, multiple-component supercritical solutions. A monomer–monomer system consisting of 2,5-distyrylpyrazine (DSP) and diethyl p-phenylenediacrylate (EPA) and a monomer–polymer system consisting of DSP and a fluorinated polyacrylate (FAA) were precipitated from supercritical chlorodifluoromethane (F22). The product morphology was investigated at several different operating conditions (concentration, nozzle temperature and pressure). Single-component (binary system) phase behavior measurements were performed and compared to that of the monomer–monomer–solvent and monomer–polymer–solvent ternary systems. The resulting particle morphology was investigated using atomic force microscope (AFM), scanning electron microscope (SEM) and optical microscopy. It was determined that the microstructure of the composite precipitates depends strongly on the processing conditions and can range from segregated materials to encapsulated particles.
Irrigation frequency effects on leaching of cations from gypsum amended coastal plain surface soils

In low Ca soils, gypsum is applied at flowering of peanut (Arachis hypogaea L.) to insure adequate availability of Ca in the fruiting zone (0 to 8 cm soil depth) during pod development. Effects of 15.2 cm water applied as 1, 2, 4 or 12 split applications over 28-d period following the application of gypsum on the distribution of Ca and other cations in the fruiting zone and immediately below the fruiting zone (8 to 16 cm depth) were investigated on the Lakeland and Tifton soils under controlled conditions in rainout shelter plots. In Lakeland soil, the fruiting zone Ca concentration was greater for the high frequency (15.2 cm in 4 or 12 split applications) irrigation treatments than for the low frequency (15.2 cm in 1 or 2 split applications) treatments at 7 d. Those differences became non-significant after 14 d. In Tifton soil, leaching of Ca below the fruiting zone was significantly greater for the low frequency irrigation treatments than for the high frequency treatments throughout the duration of this e experiment. High frequency irrigation of moderate quantities should result in low Ca losses from the fruiting zone. Irrigation following gypsum application decreased K and Mg concentrations in the fruiting zone for both soils. The gypsum-induced leaching of K or Mg was lower in high frequency irrigation treatments than in low frequency treatments. High frequency irrigation following gypsum application resulted in a decrease in soil pH during the initial 7 d.
High-resolution transmission electron microscopy study of defects and interfaces in epitaxial TiO2 films on sapphire and LaAlO3

Abstract TiO2 thin films grown on sapphire (α-Al2O3) (1102) and on LaAlO3 (001) at 800° C by pulsed-laser deposition have been characterized by transmission electron microscopy. The TiO2 thin films grown on LaAlO3 (001) crystallize in anatase, while those on sapphire (1102) crystallize in rutile. The epitaxial relationship between the anatase thin films and the LaAlO3 substrate is (004)[110]A//(001)[110]L, where the subscripts A and L indicate anatase and LaAlO3 respectively, and that between the rutile thin films and the sapphire substrate is (011)[111]R//(1102)[202 1]S, where the subscripts R and S indicate rutile and sapphire respectively. The rutile thin films contain a high density of growth twins with (101) and (011)T being the twin planes and [101] being the twinning direction, where the subscript T represents a twinning plane. The atomic structure of the twin boundary, the anatase-LaAlO3 and the rutile-sapphire interfaces were investigated by high-resolution transmission electron microscopy in com...
Characterization of neurons in the area of the medullary lateral reticular nucleus responsive to noxious visceral and cutaneous stimuli.

Abstract In halothane-anesthetized rats, 283 caudal medullary neurons responsive to colorectal distension (CRD) were characterized using extracellular electrodes. Neurons inhibited by CRD (n=82) were in the area dorsal to the lateral reticular nucleus (LRN). Most neurons excited by CRD (n=130) were located within or immediately adjacent to the LRN, were excited by noxious heat and/or noxious pinch of at least half the body surface and were called bilateral nociceptive specific (bNS) neurons. bNS neurons had accelerating responses to graded CRD (threshold: 20±2 mmHg). Ten of twelve bNS neurons tested could be antidromically activated by electrical stimulation of the midline cerebellum. Other neurons excited by CRD (n=71) had mixed responses to cutaneous stimuli and were generally located in the area dorsal to the LRN. Increases in blood pressure due to intravenous phenylephrine did not significantly alter the spontaneous activity of neurons excited by CRD, but altered spontaneous activity (12 excited, four inhibited) in all neurons tested which were inhibited by CRD. Decreases in blood pressure produced by intravenous nitroprusside produced a reciprocal response in most neurons inhibited by CRD and had a delayed onset (20–30 s after bolus administration) excitatory effect on 21 of 27 units excited by CRD. Combined with other studies, these data suggest a role for neurons within and adjacent to the LRN in the modulation of visceral nociception. They also implicate a role for the cerebellum in visceral nociceptive processing.
Generating the kernel of a staircase starshaped set from certain staircase convex subsets

Let S be an orthogonal polygon in the plane. Assume that S is starshaped via staircase paths, and let K be any component of Ker S, the staircase kernel of S, where K ≠ S. For every x in S\K, define W K (x) = {s: s lies on some staircase path in S from x to a point of K}. There is a minimal (finite) collection W(K) of W K (x) sets whose union is S. Further, each set W K (x) may be associated with a finite family U K (x) of staircase convex subsets, each containing x and K, with ∪{U: U in U K (x)} = W K (x). If W(K) = {W K (x 1), ..., W K (x n )}, then K ⊆ V K ≡ ∩{U: U in some family U K (x i ), 1 ≤ i ≤ n} ⊆ Ker S. It follows that each set V K is staircase convex and ∪{V k : K a component of Ker S} = Ker S. Finally, if S is simply connected, then Ker S has exactly one component K, each set W K (x i ) is staircase convex, 1 ≤ i ≤ n, and ∩{W k (x i ): 1 ≤ i ≤ n} = Ker S.
A model of extraordinary social engagement, or "moral giftedness".

Academically and artistically talented youngsters have been well studied, but little focus has been directed to understanding young activists. This chapter considers what elements might contribute to a clear pattern of moral action in a young person who is “morally gifted.”
Pentafluoro-λ6-sulfanyl (SF5) fluoroalkyl iodides

Abstract Fluoroalkyl iodides are an important class of compounds used in the preparation of large numbers of fluoro-organo and fluoro-organometallic derivatives. We report the synthesis of several SF 5 -containing fluoroalkyl iodides derived from an improved synthesis of SF 5 CF 2 CF 2 I. They are: SF 5 CF 2 CF 2 CH 2 CH 2 I, SF 5 CF 2 CF 2 CF 2 CF 2 I, SF 5 CF 2 CF 2 (CH 2 CH 2 ) 2 I, SF 5 CF 2 CF 2 CH=CHI/isomer and SF 5 CF 2 CF 2 CHFCF 2 I/isomer. In addition, the higher homologs SF 5 (CF 2 ) 6 I, SF 5 CF 2 CF 2 (CHFCF 2 ) 2 I/isomer and SF 5 CF 2 CF 2 (CH 2 CH 2 ) 3 I have been identified.
Limits of scalar diffraction theory for diffractive phase elements

The range of validity and the accuracy of scalar diffraction theory for periodic diffractive phase elements (DPE’s) is evaluated by a comparison of diffraction efficiencies predicted from scalar theory to exact results calculated with a rigorous electromagnetic theory. The effects of DPE parameters (depth, feature size, period, index of refraction, angle of incidence, fill factor, and number of binary levels) on the accuracy of scalar diffraction theory is determined. It is found that, in general, the error of scalar theory is significant (∊ > ±5%) when the feature size is less than 14 wavelengths (s < 14λ). The error is minimized when the fill factor approaches 50%, even for small feature sizes (s = 2λ); for elements with an overall fill factor of 50% the larger period of the DPE replaces the smaller feature size as the condition of validity for scalar diffraction theory. For an 8-level DPE of refractive index 1.5 analyzed at normal incidence the error of the scalar analysis is greater than ±5% when the period is less than 20 wavelengths (Λ < 20λ). The accuracy of the scalar treatment degrades as either the index of refraction, the depth, the number of binary levels, or the angle of incidence is increased. The conclusions are, in general, applicable to nonperiodic as well as other periodic (trapezoidal, two-dimensional) structures.
Magnetic response of spin-density waves in a quasilinear half-filled Hubbard band

The linear and nonlinear response of spin-density waves (SDW) to a magnetic field is studied in a quasi-one-dimensional half-filled Hubbard band within a mean-field approximation. We find that the linear transverse susceptibility remains nearly temperature independent below the SDW transition, while the longitudinal susceptibility drops exponentially with the temperature. At low fields we prove that the free energy is minimum when the field is perpendicular to the spontaneous magnetization and maximum when it is parallel. Regardless of its magnitude, a transverse field is shown to have no significant effect on the temperature dependence of the spontaneous magnetization and the susceptibility in agreement with data. On the other hand, a large longitudinal field destroys the SDW. In this case the free energy is maximum and a much lower energy is obtained by reorienting the spontaneous magnetization perpendicular to the field. The relevance of the results to the organic conductors ${(\mathrm{TMTSF})}_{2}X$ (tetramethyltetraselenafulvalene; $X=\mathrm{P}{\mathrm{F}}_{6} \mathrm{and} \mathrm{As}{\mathrm{F}}_{6}$) is discussed.
Fiber-optic nanosensors for single-cell monitoring

This article is an overview of the fabrication, operating principles, and applications of fiber-optic nanobiosensors with the capability of in-vivo analysis at the single-cell level. Recently, the cross-disciplinary integration of nanotechnology, biology, and photonics has been revolutionizing important areas in molecular biology, especially diagnostics and therapy at the molecular and cellular level. Fiber-optic nanobiosensors are a unique class of biosensor that enable analytical measurements in individual living cells and the probing of individual chemical species in specific locations within a cell. This article provides a review of the research performed in our laboratory and discusses the usefulness and potential of this nanotechnology-based biosensor system in biological research and its applications to biomonitoring of individual cells.
Introducing positive psychology: Finding a place within school psychology

An introduction to the special issue addressing positive psychology and its “place” in and implications for schools is provided. The articles contained within the issue are described within the context of our perspective regarding positive psychology in schools. As the study of positive psychology continues to evolve, it is likely that its application within other fields (including school psychology) will be more clearly expressed. We contend that the “success” of introducing, implementing, and sustaining positive psychology within schools may be dependent on its early yet also sustained integration across multiple contexts. And, a “positive” school psychology will require attention to the convergence of multiple, diverse areas of literature. The articles within this special issue begin this movement toward finding either a place for positive psychology within school psychology or a place for school psychology within positive psychology. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 1–5, 2004.
Clathrin Regulates the Association of PIPKIγ661 with the AP-2 Adaptor β2 Appendage

The AP-2 clathrin adaptor differs fundamentally from the related AP-1, AP-3, and AP-4 sorting complexes because membrane deposition does not depend directly on an Arf family GTPase. Instead phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) appears to act as the principal compartmental cue for AP-2 placement at the plasma membrane as well as for the docking of numerous other important clathrin coat components at the nascent bud site. This PtdIns(4,5)P2 dependence makes type I phosphatidylinositol 4-phosphate 5-kinases (PIPKIs) lynchpin enzymes in the assembly of clathrin-coated structures at the cell surface. PIPKIγ is the chief 5-kinase at nerve terminals, and here we show that the 26-amino acid, alternatively spliced C terminus of PIPKIγ661 is an intrinsically unstructured polypeptide that binds directly to the sandwich subdomain of the AP-2 β2 subunit appendage. An aromatic side chain-based, extended interaction motif that also includes the two bulky C-terminal residues of the short PIPKIγ635 variant is necessary for β2 appendage engagement. The clathrin heavy chain accesses the same contact surface on the AP-2 β2 appendage, but because of additional clathrin binding sites located within the unstructured hinge segment of the β2 subunit, clathrin binds the β2 chain with a higher apparent affinity than PIPKIγ661. A clathrin-regulated interaction with AP-2 could allow PIPKIγ661 to be strategically positioned for regional PtdIns(4,5)P2 generation during clathrin-coated vesicle assembly at the synapse.
Langevin Representation of Coulomb Collisions in PIC Simulations

An efficient grid-based Langevin formulation is developed for treating electron?electron (e-e) and electron?ion collisions within a particle-in-cell plasma simulation code. The formulation is energy- and momentum-conserving. If the thermal part of the electron velocity distribution is reasonably close to isotropy in any local frame of reference, the basic scattering algorithm is quantitatively accurate for electrons with any value of energy. This is particularly important in calculating the approach to equilibrium of the high-energy tail, or the equilibrium under the competing influences of e-e collisions, inelastic electron?neutral collisions, and end losses through sheaths. If the electron velocity distribution is multi-peaked or very anisotropic, accurate calculations can be performed by representing the electrons as a superposition of several beams. Computational examples are given illustrating both equilibrium energy distribution and approach to equilibrium.
Optimization of the Matrix Solid Phase Dispersion Extraction Procedure for the Analysis of Polybrominated Diphenyl Ethers in Human Placenta

Characterization of prenatal exposure to hazardous chemicals most often relies upon the analysis of cord blood. However, human placenta is an appropriate tissue alternative with noteworthy advantages. Owing to analytical challenges, reports on placental levels of toxic chemicals are limited. The purpose of this study was to establish a reliable, cost-effective, and relatively fast and simple method to extract polybrominated diphenyl ethers (PBDEs) from human placenta for analysis using gas chromatography coupled with mass spectrometry (GC/MS). The matrix solid phase dispersion (MSPD) method was optimized for the extraction and analysis of 43 PBDEs (including BDE209) from human placenta samples. Different sorbents, sample conditions, grinding methods, elution solvents, and single and repeated extractions were compared for their effects on the extraction efficiency. The performance of the optimized method was validated by analyzing spiked placenta samples and a standard reference material of fish tissue. Co...
Discovery of a New Molecular Probe ML228: An Activator of the Hypoxia Inducible Factor (HIF) Pathway

Hypoxia and ischemia are linked to several serious public health problems that affect most major organ systems. Specific examples include diseases of the cardiovascular, pulmonary, renal, neurologic, and musculoskeletal systems. The most significant pathway for cellular response to hypoxia is the hypoxia inducible factor (HIF) pathway. HIFs are transcription factors responsible for the activation of genes which encode proteins that mediate adaptive responses to reduced oxygen availability. A high-throughput cell-based HIF-mediated gene reporter screen was carried out using the NIH’s Molecular Libraries Small Molecule Repository to identify activators of the HIF pathway. This communication describes the subsequent medicinal chemistry optimization of a triazine scaffold that led to the identification of the new molecular probe ML228. A discussion of HIF activation SAR within this chemotype as well as detailed in vitro characterization of the probe molecule is presented here.
Variational calculations and Bogolubov transformations.

The usefulness of the Bogolubov transformations in variational calculations is demonstrated using the massive Thirring model as a specific example. It is shown that such transformations can be chosen so that the expectation value of the Hamiltonian is regulator independent when the exact form of the counterterms is used. Moreover enough freedom is left to optimize the variational state as a trial vacuum. The problem of dealing with the anomalous commutators that arise in the model is discussed.