cssi/SciSciGPT-SciSciNet huggingface dataset:
Phase inversion dynamics of PLGA solutions related to drug delivery. Part II. The role of solution thermodynamics and bath-side mass transfer

The role of solvent properties and bath-side composition on the phase inversion dynamics and in vitro protein release kinetics of polylactic-co-glycolic acid (PLGA) solutions has been examined using dark ground imaging, in vitro release rate, and SEM techniques. Thermodynamic phase diagrams for three model systems (PLGA in 1-methyl-2-pyrrolidinone (NMP), triacetin, and ethyl benzoate) suggest two general classes of precipitation behavior, depending on the relative solvent strength and water miscibility. Drug release from the NMP-based system is primarily governed by the dynamics of phase inversion and exhibits a distinct burst region followed by a much slower release. Alternatively, depots with low solvent/water affinity (PLGA in triacetin or ethyl benzoate) undergo much slower phase inversion, resulting in a less porous, more fluid, two-phase structure that also releases protein more uniformly. Addition of a small chain triglyceride or organic salt to the aqueous receptor bath also evokes a significant increase in the mass transfer rate of protein from the low solvent/non-solvent affinity depots. An interpretation of these results in terms of a qualitative model for the protein release mechanism is also given.
Descemet’s Stripping Endothelial Keratoplasty (DSEK) and Glaucoma

Posterior lamellar corneal procedures are gaining widespread acceptance as the surgical procedure of choice in cases of endo­thelial dysfunction. These offer more rapid visual recovery and more predictable refractive outcomes compared to penetrating keratoplasty. Originally developed by Melles and modified by Terry, deep lamellar endothelial keratoplasty (DLEK) evolved into Descemet stripping endothelial keratoplasty with (DSAEK) or without (DSEK) the use of an automated microkeratome. As the procedure and the pertinent instrumentation are undergoing refinements, little is known about the management of glaucoma that may coexist or arise as a result of posterior lamellar corneal procedures. We will review the available information on the incidence of glaucoma after DSEK/DLEK, the error of measurement in intraocular pressure (IOP) with the Goldmann applanation tonometer (GAT) and summarize considerations about the surgical management of glaucoma in patients after DSEK/DLEK.
Use of (meth)acrylamides as alternative monomers in dental adhesive systems.

Abstract Objectives: Methacrylamides are proposed as components for dental adhesive systems with enhanced resistance to hydrolytic and enzymatic degradation. The specific objective of this study was to evaluate the polymerization kinetics, water sorption and solubility, pH-derived degradation and microtensile bond strength of various monofunctional acrylamides and meth(acrylamides) when copolymerized with dimethacrylates. Methods: Base monomers were added at 60 wt%, and included either BisGMA or UDMA. Monofunctional monomers were added at 40 wt%, including one (meth)acrylate as the control, two secondary methacrylamides and two tertiary acrylamides. DMPA (0.2 wt%) and DPI-PF6 (0.4 wt%)/BHT (0.1 wt%) were added as initiators/inhibitor. Polymerization kinetics wwere followed with near-IR spectroscopy in real time. Water sorption (WS) and solubility (SL) were measured following ISO 4049. Monomer degradation at different pH levels was assessed with 1H NMR. Microtensile bond strength (MTBS) was assessed in caries-free human third molars 48 h and 3 weeks after restorations were placed using solvated BisGMA-based adhesives (40 vol% ethanol). Data were analyzed with one-way ANOVA/Tukey’s test (α = 0.05). Results: As expected, rate of polymerization and final degree of conversion (DC) were higher for the acryl versions of each monomer, and decreased with increasing steric hindrance around the vinyl group for each molecule. In general, UDMA copolymerizations were more rapid and extensive than for BisGMA, but this was dependent upon the specific monofunctional monomer added. WS/SL were in general higher for the (meth)acrylamides compared to the (meth)acrylates, except for the tertiary acrylamide, which showed the lowest values. One of the secondary methacrylamides was significantly more stable than the methacrylate control, but the alpha substitutions decreased stability to degradation in acid pH. MTBS in general was higher for the (meth)acrylates. While for all materials the MTBS values at 3 weeks decreased in relation to the 24 h results, the tertiary acrylamide showed no reduction in bond strength. Significance: This study highlights the importance of considering steric and electronic factors when designing monomers for applications where rapid polymerizations are needed, especially when co-polymerizations with other base monomers are required to balance mechanical properties, as is the case with dental adhesives. The results of this investigation will be used to design fully formulated adhesives to be tested in clinically-relevant conditions.
Productivity and Income Inequality Growth Rates in the United States

Abstract This paper examines the relationship between the size distribution of income and productivity. We are particularly interested in whether or not exogeneity tests indicate that the inequality and productivity relationship runs both ways. Bivariate and multivariate causality tests and impulse response functions from a vector autoregression are calculated. There is considerable evidence that productivity growth rates and inequality growth rates are inversely related. The main lesson from this study is that policies designed to affect productivity growth or income inequality should be considered simultaneously.
Special Education Teachers’ Experience, Confidence, Beliefs, and Knowledge About Integrating Technology:

This study investigated the perspectives of elementary special education teachers regarding integrating technology into lessons. Eight special education teachers at a private university laboratory ...
Analysis of high-frequency ANCF modes: Navier–Stokes physical damping and implicit numerical integration

This paper is concerned with the study of the high-frequency modes resulting from the use of the finite element absolute nodal coordinate formulation (ANCF) in multibody system (MBS) applications. The coupling between the cross-sectional deformations and bending and extension of ANCF beam and plate elements produces high-frequency modes which negatively impact the computational efficiency. In this paper, two new and fundamentally different approaches are proposed to efficiently solve stiff systems of differential/algebraic equations by filtering and/or damping out ANCF high-frequency modes. A new objective large rotation and large deformation viscoelastic constitutive model defined by the Navier–Stokes equations, widely used for fluids, is proposed for ANCF solids. The proposed Navier–Stokes viscoelastic constitutive model is formulated in terms of a diagonal damping matrix, allows damping out insignificant high-frequency modes, and leads to zero energy dissipation in the case of rigid body motion. The second approach, however, is numerical and is based on enhancing the two-loop implicit sparse matrix numerical integration (TLISMNI) method by introducing a new stiffness detection error control criterion. The new criterion avoids unnecessary reductions in the time step and minimizes the number of TLISMNI outer loop iterations required to achieve convergence. The TLISMNI method ensures that the MBS algebraic constraint equations are satisfied at the position, velocity, and acceleration levels, efficiently exploits sparse matrix techniques, and avoids numerical force differentiation. The performance of the TLISMNI/Adams algorithm using the proposed error criterion is evaluated by comparison with the TLISMNI/HHT method and the explicit predictor–corrector, variable-order, and variable step-size Adams methods. Several numerical examples are used to evaluate the accuracy, efficiency, and damping characteristics of the new nonlinear viscoelastic constitutive model and the TLISMNI procedure.
General relativistic hydrodynamics on a moving-mesh I: static space–times

We present the first-ever moving-mesh general relativistic hydrodynamics solver for static spacetimes as implemented in the code, MANGA. Our implementation builds on the architectures of MANGA and the numerical relativity Python package NRPy+. We review the general algorithm to solve these equations and, in particular, detail the time stepping; Riemann solution across moving faces; conversion between primitive and conservative variables; validation and correction of hydrodynamic variables; and mapping of the metric to a Voronoi moving-mesh grid. We present test results for the numerical integration of an unmagnetized Tolman-Oppenheimer-Volkoff star for 24 dynamical times. We demonstrate that at a resolution of $10^6$ mesh generating points, the star is stable and its central density drifts downward by 2% over this timescale. At a lower resolution the central density drift increases in a manner consistent with the adopted second order spatial reconstruction scheme. These results agree well with the exact solutions, and we find the error behavior to be similar to Eulerian codes with second-order spatial reconstruction. We also demonstrate that the new code recovers the fundamental mode frequency for the same TOV star but with its initial pressure depleted by 10%
Estrogen Receptor Involvement in Noradrenergic Regulation of Ventromedial Hypothalamic Nucleus Glucoregulatory Neurotransmitter and Stimulus-Specific Glycogen Phosphorylase Enzyme Isoform Expression.

Norepinephrine (NE) directly regulates ventromedial hypothalamic nucleus (VMN) glucoregulatory neurons and also controls glycogen-derived fuel provision to those cells. VMN nitric oxide (NO) and γ-...
Chapter 6 – Organofluorine Anesthetics

Organofluorine inhalation anesthetics, such as isoflurane, desflurane, enflurane, and sevoflurane, are safer alternatives compared to other intravenous general anesthetics, as they are relatively volatile and nonflammable. These anesthetics are currently administered as racemic mixtures due to the technological issues concerning the large-scale production of chiral compounds. The mechanisms of action of the inhalation anesthetics is still under debate, although there is general agreement that they exert their anesthetic effect by reversibly binding to ligand-gated ion channels (LGIC) or by binding to the guanine-nucleotide-binding protein-coupled receptors (GPCR), thereby causing disruption of signal transduction. This chapter outlines synthesis, hepatotoxicity, and the anesthetic effects of the widely used fluorinated inhalation anesthetics.
Denoising sparse images from GRAPPA using the nullspace method

To accelerate magnetic resonance imaging using uniformly undersampled (nonrandom) parallel imaging beyond what is achievable with generalized autocalibrating partially parallel acquisitions (GRAPPA) alone, the DEnoising of Sparse Images from GRAPPA using the Nullspace method is developed. The trade-off between denoising and smoothing the GRAPPA solution is studied for different levels of acceleration. Several brain images reconstructed from uniformly undersampled k-space data using DEnoising of Sparse Images from GRAPPA using the Nullspace method are compared against reconstructions using existing methods in terms of difference images (a qualitative measure), peak-signal-to-noise ratio, and noise amplification (g-factors) as measured using the pseudo-multiple replica method. Effects of smoothing, including contrast loss, are studied in synthetic phantom data. In the experiments presented, the contrast loss and spatial resolution are competitive with existing methods. Results for several brain images demonstrate significant improvements over GRAPPA at high acceleration factors in denoising performance with limited blurring or smoothing artifacts. In addition, the measured g-factors suggest that DEnoising of Sparse Images from GRAPPA using the Nullspace method mitigates noise amplification better than both GRAPPA and L1 iterative self-consistent parallel imaging reconstruction (the latter limited here by uniform undersampling). Magn Reson Med 68:1176–1189, 2012. V C 2011
Ghost guns: spookier than you think they are.

Off-the-books, untraceable “ghost guns” can now be manufactured at home, easily, and in large numbers; they contribute ever more frequently to firearm violence, including hate violence and domestic terrorism. The Bureau of Alcohol, Tobacco, Firearms and Explosives estimates that in 2019 alone, law enforcement agencies recovered more than 10,000 ghost guns. The manuscript describes the current situation and suggests specific actions that state and federal governments can take to avert disaster.
A people’s history of leisure studies: a historiography of four traditions of critical leisure studies

Recent calls for papers in numerous academic journals within leisure studies have focused on a global and nation-specific climate that leans towards autocratic policy development, fascist rhetoric ...
Topological Learning and Its Application to Multimodal Brain Network Integration

A long-standing challenge in multimodal brain network analyses is to integrate topologically different brain networks obtained from diffusion and functional MRI in a coherent statistical framework. Existing multimodal frameworks will inevitably destroy the topological difference of the networks. In this paper, we propose a novel topological learning framework that integrates networks of different topology through persistent homology. Such challenging task is made possible through the introduction of a new topological loss that bypasses intrinsic computational bottlenecks and thus enables us to perform various topological computations and optimizations with ease. We validate the topological loss in extensive statistical simulations with ground truth to assess its effectiveness of discriminating networks. Among many possible applications, we demonstrate the versatility of topological loss in the twin imaging study where we determine the extend to which brain networks are genetically heritable.
Systems Engineering for Artificial Intelligence-based Systems: A Review in Time

With backgrounds in the science of information fusion and information technology, a review of Systems Engineering (SE) for Artificial Intelligence (AI)-based systems is provided across time, first with a brief history of AI and then the systems’ perspective based on the lead author’s experience with information fusion processes. The different types of AI are reviewed, such as expert systems and machine learning. Then SE is introduced and how it has evolved and must evolve further to become fully integrated with AI, such that both disciplines can help each other move into the future and evolve together. Several SE issues are reviewed, including risk, technical debt, software engineering, test and evaluation, emergent behavior, safety, and explainable AI.
Syncope, Tilt Testing, and Cardioversion

Syncope is a frequent diagnostic and therapeutic challenge for emergency room physicians, primary care providers, cardiologists and electrophysiologists. Syncope accounts for 3 % of emergency room visits and 6 % of all hospital admissions, with a lifetime incidence of nearly 40 %. Syncope is derived from the Greek word synkopē, which means “to cut short” or “to interrupt”. Syncope is defined by transient loss of consciousness due to global cerebral hypoperfusion. It is characterized by rapid onset, short duration, and spontaneous complete recovery. Understanding the pathophysiological basis for the syncopal episode is the most useful tool for etiology-based treatment and risk assessment. The classification of syncope based on pathophysiology is discussed.
Chapter 7 GABAergic circuits in the mammalian retina

Publisher Summary This chapter focuses on specific gamma-aminobutyric acid–releasing (GABAergic) retinal neurons and discusses their role in the retinal circuitry of eutherian mammals. Many distinct types of interneurons convey the visual scene, transduced by rods and cones, to the ganglion cells. The cat retina has been estimated to contain 33 types of interneurons and 23 types of ganglion cells. These interneurons form two major pathways: the rod-bipolar pathway and the cone-bipolar pathway. This arrangement may be common to mammals. The pathways begin in the outer plexiform layer. Putative GABAergic neurons have been located by several methods: the autoradiography of tritiated GABA or its tritiated analogues (isoguvacine, diaminobutyric acid, and muscimol)—after these substances are accumulated by neurons—shows grains over somas and processes. The structure of the rod bipolar cell dyad synapse—with its putative reciprocal, GABAergic amacrine—is well characterized, and recently some success at isolating its constituent neurons has been made.
Reviving the Subject of Law

This essay is an advanced draft of work that will be published in On Philosophy and American Law (Francis J. Mootz III ed. forthcoming, Cambridge U.P., 2009). This edited collection includes responses by a wide range of scholars working in legal theory to Mootz's challenge to respond to the current state of American legal philosophy, using Karl Llewellyn's 1934 University of Pennsylvania law review account of the emergence of legal realism as a prompt. Drawing on the author's recent scholarship on the emergence of a distinctive and impoverished model of common law judging in the U.S. since the mid-c 20th, and taking its lead from Duncan Kennedy's suggestive argument that Realism failed to gain traction in Europe because of the obscene cast that the Third Reich gave to its project, the essay gives a critical account of the contemporary inheritances of the Realists' account of law and their reliance on social science. It argues that interdisciplinary work in studies of law and the linguistic humanities and human sciences might be deployed in reviving the subject of law, generating a thick account of what law is and might be, of how its institutions, discourses, texts and subjects are formed in culture and history, and of how legal subjects reproduce culture and make history in their turn.
Mathematical models governing dynamic user-driven resource allocation

In many complex computer-driven tasks, select information is hidden from users, either on purpose or inadvertently. When this is the case, users may become frustrated because they are not alerted to the causes of delays or other malfunctions. In turn, overall efficiency of a system can decrease while users wait for the system to time out or otherwise resolve the delay. One way to minimize the ill effects of resource conflicts is to involve users in the process of determining resource allocation by providing a forum for self-governance and problem resolution.
"The Blackness of the Day": Job's Regressive Paradise as Creation Unmade

Early in his book Tears and Saints , E. M. Cioran (1995: 17-18) describes the “original forgotten vision” which individuals pursue as they age. Cioran argues that God is everyone’s initial memory, and he asks, “Are they haunted by dateless memories which evoke the immediate proximity of God in paradise? Could they be hiding in the depths of their memory the figure of Divinity?” The entrapment individuals feel, being subject to temporality, inevitably awakens an awareness or a foreboding of the otherworldly, the eternal. Cioran is fascinated – and maddened – by saints, for they alone are able to successfully enter “dateless memories,” indeed the very presence of God, although what they aim for is not completely grasped. Increasing age is not the only thing that propels individuals to retrogressively pursue their first memory of God, if indeed this is true; suffering also has the power to drive one toward one’s original memory, God (hence why many of the saints, particularly in their youth, inflict suffering upon themselves in pursuit of mystical rapture). Such is the case in the book of Job; readers are introduced to Job, a man who is “blameless, upright, fearing God and turning away from evil” (Job, 1, 1). Nevertheless, God agrees twice to allow Job to suffer in response to Satan’s requests. As calamity sets upon him over the course of two separate days, Job’s mind turns not to nostalgia but instead to God himself; Job pursues God in an attempt to place his suffering in a suitable and sufficient framework for understanding. Job also pursues God in an attempt to investigate this perceived change in God, who now seems not beneficent but malevolent. While Job chooses to pursue God through the despair caused by his [Job’s] undeserved suffering, readers should be uneasy with Satan’s return into God’s court,
The treatment of female stress urinary incontinence: an evidenced-based review

Objective To review the literature on the surgical and nonsurgical treatment options for stress urinary incontinence in women, focusing exclusively on randomized clinical trials and high quality meta-analyses.
Horizontal merger analysis in retail markets

In this essay, we describe antitrust analysis of horizontal mergers in U.S. retail markets. We begin by providing a brief overview of the economic and legal framework governing horizontal merger policy, and highlight key issues in analyzing retail mergers. Next, we discuss the changing legal treatment of retailing mergers by providing a description of four major merger challenges brought by U.S. antitrust authorities over the last 50 years. We then provide a detailed discussion of the economic tools used to analyze retailing mergers. We start by presenting a frequently used model of retail competition to illustrate how retail mergers can create or enhance market power. We then describe a variety of structural and reduced form empirical techniques that can be used to quantify competition between merging retailers and, in some cases, to forecast merger price effects.
Identification of a Precursor to Phosphatidyl Choline-Specific B-1 Cells Suggesting That B-1 Cells Differentiate from Splenic Conventional B Cells In Vivo: Cyclosporin A Blocks Differentiation to B-1

The origin of B-1 cells is controversial. The initial paradigm posited that B-1 and B-2 cells derive from separate lineages. More recently it has been argued that B-1 cells derive from conventional B cells as a result of T-independent Ag activation. To understand B-1 cell differentiation, we have generated Ig transgenic (Tg) mice using the H and L chain genes (VH12 and Vκ4) of anti-phosphatidyl choline (anti-PtC) B cells. In normal mice anti-PtC B cells segregate to B-1. Segregation is intact in VH12 (6-1) and VH12/Vκ4 (double) Tg mice that develop large numbers of PtC-specific B cells. However, if B-1 cell differentiation is blocked, anti-PtC B cells in these Tg mice are B-2-like in phenotype, suggesting the existence of an Ag-driven differentiative pathway from B-2 to B-1. In this study, we show that double Tg mice have a population of anti-PtC B cells that have the phenotypic characteristics of both B-2 and B-1 cells and that have the potential to differentiate to B-1 (B-1a and B-1b). Cyclosporin A blocks this differentiation and induces a more B-2-like phenotype in these cells. These findings indicate that these cells are intermediate between B-2 and B-1, further evidence of a B-2 to B-1 differentiative pathway.
Adding trees to irrigated turfgrass lawns may be a water-saving measure in semi-arid environments

Evapotranspiration (ET) of irrigated urban plants is a large yet uncertain component of urban water budgets in semi-arid regions. A detailed understanding of plot-scale ET and its sensitivity to plant species composition is necessary to improve estimates of urban water vapour fluxes and water balance. We used portable enclosed chambers and empirical equations to quantify ET from (1) unshaded urban lawns covered exclusively by turfgrass and (2) urban lawns comprised of open-grown trees and turfgrass groundcover in the Los Angeles Metropolitan area. Turfgrass at all locations had a non-limiting supply of soil water because of regular sprinkler irrigation. ET of irrigated turfgrass reached a maximum of 10. 4 ± 1·3 mm d−1 and was always higher than plot-scale tree transpiration, which did not exceed 1 mm d−1. In summer, total plot ET of the lawns with trees was lower than lawns without trees by 0·9–3·9 mm d−1. Turfgrass ET was highly sensitive to solar radiation, and the ratio of ET of lawns with trees to ET of lawns without trees decreased with tree canopy cover. Hence, reductions in turfgrass ET caused by shading effects of open-grown trees were more important in influencing total landscape ET than the addition of tree transpiration. This suggests that low-density planting of trees that partially shade irrigated urban lawns may be a water-saving measure in semi-arid irrigated environments. Copyright © 2013 John Wiley & Sons, Ltd.
Is there a relationship between hepatitis B surface antibody status and diabetes

摘要 乙型肝炎病毒感染与肝病相关的发病率以及死亡率显著增加有关1。在发生慢性乙型肝炎病毒(HBV)感染时存在糖尿病也与阴性肝病结果有关,而且与非糖尿病患者相比肝病进展更快,发生肝癌的风险也更高2-4。迄今为止在感染HBV的患者中评估糖尿病患病率的可用信息很有限,主要来自于亚洲流行地区,报告的患病率范围为6%至14%5-7。最近来自北美HBV感染人群参与的乙型肝炎研究网络数据发现患病率为13%,这比普通人群报告的(9%)更高8。虽然目前已经明确丙型肝炎病毒(HCV)感染与代谢异常(例如胰岛素抵抗与糖尿病)之间具有相关性,并且根治丙型肝炎病毒感染后可使这些指标得以改善9-12,但是HBV本身并没有表现出与糖尿病相关13。实际上在一个大型的具有良好特征的北美HBV感染人群中,除了已知的代谢危险因素之外,糖尿病与升高的丙氨酸氨基转移酶水平之间具有相关性,但是与HBV病毒水平无关,这表明糖尿病与宿主因素之间的关系与病毒因素相比更为紧密8。此外,最近在一项大型的纵向研究中对阿拉斯加土著居民人群进行了超过20年的随访,发现存在HBV感染并不会影响糖尿病的发生14。然而,与普通人群相比,糖尿病人群的HBV感染患病率更高,因此推荐在糖尿病患者中筛查乙型肝炎并且对易感个体进行接种15。 Li等16的回顾性队列研究的目的是在中国退休工人中(所有的人年龄都> 50岁,他们都参与了一个健康体检项目,既往没有已知的糖尿病病史)评估存在乙型肝炎表面抗体(HBsAb)与葡萄糖耐量状态之间的关系。该研究使用的方法是口服葡萄糖耐量试验,它与空腹血糖截点相比能够诊断出更多的糖尿病患者17。然而,存在HBsAb代表的是既往感染过HBV或者是通过接种后导致的免疫结果,但这个人群的HBV疫苗接种状态信息不明。作者推断在女性参与者中存在HBsAb与糖尿病之间没有相关性。 虽然这一发现很有趣,但是作者应该谨慎地解释他的结论。首先, HBsAb阳性以及抗HBV治疗可能有助于减少经绝后妇女的胰岛素抵抗与糖尿病风险这一结论是错误的,因为这项横向研究设计并不能得出因果关系。此外,由于HBsAb阴性组可能还没有感染HBV或者接受过接种,因此并不能够得出在该人群中HBsAb的阳性状态可能代表了更好的先天性和/或获得性免疫调节并且有助于改善胰岛素抵抗与降低糖尿病风险这一结论。另外,还不明确不同的性别对于HBsAb与糖尿病风险之间的阴性相关关系的影响为什么不同。然而,最近一项对7142名无糖尿病的多民族成年人的研究,这些成年人都参与了2005至2010年全国健康与营养调查研究(National Health and Nutrition Examination Survey,NHANES)(在2014年美国糖尿病协会年会上以摘要形式展出),结果发现接种HBV疫苗与较低的糖尿病风险之间具有相关性,而这项研究是通过空腹血糖水平来诊断糖尿病的18。根据此研究,在1412名曾经接受过乙型肝炎疫苗接种的参与者中有1.13%的人发生了糖尿病,而对照的5730名未接种的参与者中有5.67%的人发生了糖尿病18。与Li等人的研究16相似,NHANES研究18并不能得出明确的因果关系,并且接种患者可能代表了一个无法测定危险因素的人群,我们也不能够排除他们固有的糖尿病风险就较低。虽然如此,这些观察结果提示将来可能需要纵向研究来明确抗HBV感染免疫状态与糖尿病风险之间的关系,特别是在全世界都可以接种HBV疫苗的时代。
A BME solution of the inverse problem for saturated groundwater flow

In most real-world hydrogeologic situations, natural heterogeneity and measurement errors introduce major sources of uncertainty in the solution of the inverse problem. The Bayesian Maximum Entropy (BME) method of modern geostatistics offers an efficient solution to the inverse problem by first assimilating various physical knowledge bases (hydrologic laws, water table elevation data, uncertain hydraulic resistivity measurements, etc.) and then producing robust estimates of the subsurface variables across space. We present specific methods for implementing the BME conceptual framework to solve an inverse problem involving Darcy’s law for subsurface flow. We illustrate one of these methods in the case of a synthetic one-dimensional case study concerned with the estimation of hydraulic resistivity conditioned on soft data and hydraulic head measurements. The BME framework processes the physical knowledge contained in Darcy’s law and generates accurate estimates of hydraulic resistivity across space. The optimal distribution of hard and soft data needed to minimize the associated estimation error at a specified sampling cost is determined.
Collisions with relative acceleration and cross sections in velocity space

Abstract The kinetic formula for collisional frequency as a product of particle concentration, cross section and relative velocity is based on the assumption that the latter is constant before and after the collision. This result is here generalized to include the case of collisions with relative acceleration and this is found to involve a cross section in velocity space and the number of particles per unit volume of velocity space. The argument proceeds from the relaxational Boltzmann equation satisfied by the probability density of localization in phase space. The Gauss divergence theorem is applied in the positional and velocity subspaces to convert a space integration and a velocity space integration into the corresponding surface integrations and under the assumptions of unidirectional relative velocity and relative acceleration the two kinds of cross section are obtained naturally.
Computer facilitation of communication within professional communities

This report is based on several projects at the University of Michigan. The software used is CONFER, a computer-augmented conferencing program. Access is provided nationally through TELENET data services. The paper describes hardware and software for information systems at the University of Michigan, the development of CONFER, and a rationale for computer-aided communication within professional communities. Six applications of this particular software and system are summarized: national committees, regional planning groups, on-campus working groups, and user consulting services. One innovative application (support of an international congress held recently in Ann Arbor) is described in detail. Computer-based conununications were used for sending messages, adjusting schedules, planning additional sessions and trips, and developing written material through computer-mediated caucuses on specific topics. Contributions of computing to professional communications are summarized, with particular attention given to projected impact on teaching and research in universities.
Distribution and abundance of aquatic macroinvertebrates following drought in three prairie pothole wetlands

We collected aquatic macroinvertebrates in a seasonal, semipermanent, and permanent pothole wetland in southwestern Manitoba, Canada to determine their abundance and distribution following drought in relation to the prelaying, egg-laying and brood-rearing periods of canvasbacks (Aythya valisineria). We collected 26 taxa of nektonic macroinvertebrates of which 6 major groups (Cladocera, Copepoda, Ostracoda, Culicidae, Dytiscidae, Gastropoda) collectively comprised >98% of the total number of individuals. The number of nektonic macroinvertebrates peaked during the egg-laying period, and crustaceans were the most abundant taxa in all 3 potholes during all 3 breeding periods. We collected 50 families of emergent insects and several unknown families in the orders Coleoptera and Diptera. Five major groups (Chironomidae, Culicidae, other Diptera, Coleoptera, Leptoceridae) collectively comprised >97% of the total number. Insect emergence increased during the breeding season to a peak during the brood-rearing period. Chironomids were the most abundant emergent insect during all 3 breeding periods and were most abundant in the permanent pothole. Chironomids collected on artificial substrates also were most abundant in the permanent pothole during all 3 breeding periods. The number of gastropods was greatest during the laying and broodrearing periods. Following drought, it appeared that macroinvertebrates were abundant and widely distributed in the 3 potholes.
Old World Teaching Meets the New Digital Cultural Creatives

This article sets forth a conceptual, philosophical and social agenda for art and design education in the twenty-first century, considering how a set of beliefs articulated within US art education discourse interfaces with conceptualisations about emerging global digital media and technologies. Discussion highlights selected writings in the USA primarily, writings about art education technology orientations; and then describes the professional experiences and insights of the writer as she embraced, implemented and made sense of technology in terms of her own multicultural educational orientation in a US university. Based on these insights, this writer proposes that technology pedagogy is not actually about digital technologies per se, but about what we intend to do with new technologies in the twenty-first century. Old notions of art as an embodiment of things that matter and a testament to the human condition are now connected to contemporary ideas about citizenship, caring and public engagement. In this trajectory, citizenship education is then posed as central to a future vision of art education in the digitally connected classroom. Caveats and limitations of the educational and transformative power of new global electronic media being set forth in this article are also noted, including paradoxical self-contradictions within the orientation itself.
Schiff base complexesA numerical study of the nickelII—pyruvate—glycinate system using a high speed computer

Abstract A numerical study of the nickel II -pyruvate-glycinate system is undertaken and a computer method of solving the pertinent equations is developed. Theoretical titration curves using trial constants are calculated for conditions corresponding to those used experimentally. The observed inter-relationships between the values of the constants, the concentrations of the reactants and the resulting titration curves yield valuable information regarding the importance of the various mixed complexes under the differing conditions. The “best” set of constants which fits the experimental data according to the minimum value of the sum of the squares of the residuals, pH calc i -pH obs , i , is obtained. The results of the study lead to a procedure which should be applicable to determining the constants for mixed complex systems in general.
A three-dimensional quality-guided phase unwrapping method for MR elastography

Magnetic resonance elastography (MRE) uses accumulated phases that are acquired at multiple, uniformly spaced relative phase offsets, to estimate harmonic motion information. Heavily wrapped phase occurs when the motion is large and unwrapping procedures are necessary to estimate the displacements required by MRE. Two unwrapping methods were developed and compared in this paper. The first method is a sequentially applied approach. The three-dimensional MRE phase image block for each slice was processed by two-dimensional unwrapping followed by a one-dimensional phase unwrapping approach along the phase-offset direction. This unwrapping approach generally works well for low noise data. However, there are still cases where the two-dimensional unwrapping method fails when noise is high. In this case, the baseline of the corrupted regions within an unwrapped image will not be consistent. Instead of separating the two-dimensional and one-dimensional unwrapping in a sequential approach, an interleaved three-dimensional quality-guided unwrapping method was developed to combine both the two-dimensional phase image continuity and one-dimensional harmonic motion information. The quality of one-dimensional harmonic motion unwrapping was used to guide the three-dimensional unwrapping procedures and it resulted in stronger guidance than in the sequential method. In this work, in vivo results generated by the two methods were compared.
Progress and challenges in the application of artificial intelligence to computational fluid dynamics

An approach to analyzing CFD knowledge-based systems is proposed which is based, in part, on the concept of knowledge-level analysis. Consideration is given to the expert cooling fan design system, the PAN AIR knowledge system, grid adaptation, and expert zonal grid generation. These AI/CFD systems demonstrate that current AI technology can be successfully applied to well-formulated problems that are solved by means of classification or selection of preenumerated solutions.
Evidence for heterogeneity in the association properties of the gamma protein of mouse 7S nerve growth factor protein.

Abstract The mouse 7S nerve growth factor γ subunit, which is homogeneous with respect to molecular weight and heterogeneous with respect to charge, has been found to display heterogeneous self-association behavior at pH values 4 and 7.4.
Comparison of background gamma-ray spectra between Los Alamos, New Mexico and Austin, Texas

Background counts in gamma-ray spectrometry are caused by a variety of sources. Among these are naturally occurring radioactive materials (NORM) in the environment, interactions from cosmic radiation, and contamination within the laboratory. High-purity germanium detectors were used to acquire long background spectra in Los Alamos, NM (elevation ~7,300 feet) and Austin, TX (elevation ~500 feet). This difference in elevation has a sizeable effect on background spectra due to cosmic interactions, such as (n,n′) and (n,γ). Los Alamos also has a fairly high NORM concentration in the soil relative to Austin, and this gives way to various spectral interferences. When analyzing nuclear forensics samples, these background sources can have non-trivial effects on detection limits of low-level fission products. By accurately determining the influence that elevation and environment have on background spectra, interferences within various laboratory environments can be more accurately characterized.
Detection of estrous activity cycle by 1-hour samples of running behavior

Daily 1 h samples of activity-wheel performance yielded activity records in which the 4–5 day estrous cycle was evident in 23 of 36 albino rats. Mean activity level was still increasing at the conclusion of 60 daily periods of measurement, but a correlational analysis revealed marked stability of relative activity level.
Detrimental effects of prostaglandin F2alpha on preimplantation bovine embryos.

Abstract Two studies were performed to determine effects of prostaglandin F2α (PGF2α) on continued development of pre-compacted (in vitro-produced) and compacted (in vivo-derived) bovine embryos. In Experiment 1, pre-compacted embryos were placed in KSOM media supplemented with polyvinyl alcohol (0.3%) and assigned to the following treatments: (1) control; (2) PGF-1 (1 ng/mL PGF2α); (3) PGF-10 (10 ng/mL PGF2α); (4) PGF-100 (100 ng/mL PGF2α); or (5) PGE-5 (5 ng/mL PGE2). Following 4 days of incubation in assigned treatments, continued development of pre-compacted embryos to blastocysts was reduced by addition of PGF2α in culture medium (P=0.002). Development did not differ between control and PGE2 treatments (P>0.10). In Experiment 2, compacted morula’s were placed in KSOM-PVA supplemented media and assigned to one of four treatments: (1) control; (2) PGF-0.1 (0.1 ng/mL PGF2α); (3) PGF-1 (1 ng/mL PGF2α); and (4) PGF-10 (10 ng/mL PGF2α). After 24 h in culture, embryos were washed and placed in KSOM-BSA (0.5%) without PGF2α for an additional 48 h until assessment for development. Continued development of compacted morula to blastocyst was not affected by addition of PGF2α to the culture medium (P>0.10). However, hatching rates of embryos cultured with PGF2α were lower (P=0.05). In conclusion, it is suggested that PGF2α has a direct negative effect on continued embryonic development of pre-compacted and compacted bovine embryos.
Characterizing the metabolic phenotype: A phenotype phase plane analysis

Genome-scale metabolic maps can be reconstructed from annotated genome sequence data, biochemical literature, bioinformatic analysis, and strain-specific information. Flux-balance analysis has been useful for qualitative and quantitative analysis of metabolic reconstructions. In the past, FBA has typically been performed in one growth condition at a time, thus giving a limited view of the metabolic capabilities of a metabolic network. We have broadened the use of FBA to map the optimal metabolic flux distribution onto a single plane, which is defined by the availability of two key substrates. A finite number of qualitatively distinct patterns of metabolic pathway utilization were identified in this plane, dividing it into discrete phases. The characteristics of these distinct phases are interpreted using ratios of shadow prices in the form of isoclines. The isoclines can be used to classify the state of the metabolic network. This methodology gives rise to a "phase plane" analysis of the metabolic genotype-phenotype relation relevant for a range of growth conditions. Phenotype phase planes (PhPPs) were generated for Escherichia coli growth on two carbon sources (acetate and glucose) at all levels of oxygenation, and the resulting optimal metabolic phenotypes were studied. Supplementary information can be downloaded from our website (http://epicurus.che.udel.edu).
Poincaré and Sobolev type inequalities for vector-valued functions

Various L"p form Poincare and Sobolev type inequalities are given for functions valued in a Banach vector space. We give applications on C.
The Disruptive Behavior Rating Scale–Parent Version (DBRS-PV): Factor Analytic Structure and Validity Among Young Preschool Children

Objective: Despite recognition that disruptive behavior disorders often begin early in development, existing assessment tools are largely based on research with school-aged children. Further empirical work is needed to evaluate the utility of these tools in younger children. Methods: The present study investigated the factor structure, internal consistency, and validity of the Disruptive Behavior Rating Scale -Parent Version (DBRS-PV) in a sample of preschoolers. Participants included mothers and fathers of 261 three- to four-year-old children with and without behavior problems. Results: Findings provide support for the use of the DBRS-PV as a measure of disruptive behavior disorder symptoms in this age group, with strong internal consistency and evidence of convergent/divergent and discriminative validity. Conclusions: Results provide evidence in favor of a two-factor (a. inattention/hyperactivity -impulsivity and b. oppositional defiant behaviors) and moderate support for a three-factor (a. inattention,...
Prototypes, metaphors, metonymies and imaginative rationality in high school mathematics

The growing recognition that imagination, far from being a peripheral adjunct plays a central role in reasoning has important implications for the teaching and learning of mathematics. This paper has two main parts. In the first part, examples from high school case studies are used to illustrate prototypical mathematical images and the use of imagery in metaphoric and metonymic ways in mathematics. In the second part, pattern imagery and other types of imagery are discussed as central components in a model of mathematical reasoning. It is suggested that different forms of imagery may be used in ways that make abstraction and generalization possible in mathematics. The more abstract forms are idiosyncratically constructed by individuals. However, it is suggested that the activity of the imagination in the model presented here is central to meaning-making, and that the process makes shared meanings possible. Some social consequences for mathematics classrooms are explored briefly.
Characterization of a rat yolk sac carcinoma cell line.

Abstract A continuous cell line was established from an experimentally induced rat yolk sac carcinoma. In the early passages both visceral and parietal yolk sac carcinoma were present (designated L1). When the cell line was reestablished in culture after serial transplantations in rats, only parietal yolk sac carcinoma could be identified (designated L2). This cell line expresses parietal yolk sac endoderm characteristics in that it synthesizes basement membrane components, in particular, laminin, but also entactin, collagen IV, and heparan sulfate proteoglycan. In addition, a noncartilage chondrotin sulfate proteoglycan is synthesized. This rat yolk sac carcinoma cell line L2 will be a valuable model for the study of basement membrane components.
A dislocation dipole in an anisotropic medium

Abstract The elastic field produced by a straight dislocation dipole in an unbounded anisotropic elastic medium is investigated in the framework of the elastic continuum approximation. The problem is formulated on the basis of the solution of eigen-strain problem of anisotropic media. The result is expressed by line integrals along a contour on a unit sphere.
Altered cross‐bridge characteristics following haemodynamic overload in rabbit hearts expressing V3 myosin

1. Our goal in this study was to evaluate the effect of haemodynamic overload on cross-bridge (XBr) kinetics in the rabbit heart independently of myosin heavy chain (MHC) isoforms, which are known to modulate kinetics in small mammals. We applied a myothermal-mechanical protocol to isometrically contracting papillary muscles from two rabbit heart populations: (1) surgically induced right ventricular pressure overload (PO), and (2) sustained treatment with propylthiouracil (PTU). Both treatments resulted in a 100 % V3 MHC profile. 2. XBr force-time integral (FTI), evaluated during the peak of the twitch from muscle FTI and tension-dependent heat, was greater in the PO hearts (0.80 +/- 0.10 versus 0.45 +/- 0.05 pN s, means +/- S.E.M., P = 0.01). 3. Within the framework of a two-state XBr model, the PO XBr developed more force while attached (5.8 +/- 0.9 versus 2.7 +/- 0.3 pN), with a lower cycling rate (0.89 +/- 0.10 versus 1.50 +/- 0.14 s(-1)) and duty cycle (0.14 +/- 0.03 versus 0.24 +/- 0.02). 4. Only the ventricular isoforms of myosin light chain 1 and 2 and cardiac troponin I (cTnI) were expressed, with no difference in cTnI phosphorylation between the PO and PTU samples. The troponin T (TnT) isoform compositions in the PO and PTU samples were significantly different (P = 0.001), with TnT2 comprising 2.29 +/- 0.03 % in PO hearts versus 0.98 +/- 0.01 % in PTU hearts of total TnT. 5. This study demonstrates that MHC does not mediate dramatic alterations in XBr function induced by haemodynamic overload. Our findings support the likelihood that differences among other thick and thin filament proteins underlie these XBr alterations.
Compositional evidence regarding the origins of rims on Semarkona chondrules

This paper presents results on neutron activation analyses of the interiors and the abraded surfaces of seven chondrules from Semarkona chondrite. The results showed that six of seven chondrule rims have enhanced contents of siderophiles and chalcophiles relative to chondrule interiors, indicating that, during chondrule formation, metal/sulfide melts migrated to the exterior of the chondrule; later reheating caused this material to spread out into fine-grained rim material. For nonvolatile elements, the lithophile and siderophile element abundance patterns in the surfaces are generally similar to those in the corresponding interiors, indicating that the surface and the interior metal might have originated from a single precursor. The volatile to moderately-volatile elements K, As, and Zn tend to be enriched in the surface, compared with other elements of similar mineral affinity.
Toeplitz type operators, determining functions, principal functions, and trace formulas

We introduce and solve an operator valued Riemann-Hilbert problem defined by symbols associated with weak contractions T and operators A for which TAT∗ = A. The solution of this problem leads to a connection between such objects as the eigenvalue distribution of ¦ΘT(eit)¦ and the principal function of the hyponormal operator H = (s-limTnT∗n)12T∗.