cssi/SciSciGPT-SciSciNet huggingface dataset:
Cross-scale evaluation of dynamic crop growth in WRF and Noah-MP-Crop

Abstract Accurately representing croplands in climate models is important for simulating water and energy fluxes between the land and atmosphere, as well as evaluating the impacts of climate change on agriculture. The recent integration of dynamic crop growth in the Noah land surface model with multiparameterization (Noah-MP-Crop) has the potential to substantially advance Earth system modeling and is included in the latest release of the Weather Research and Forecasting (WRF) regional climate model. The addition of dynamic crop growth to WRF provides a unique opportunity to simultaneously evaluate biases associated with a crop model coupled to a regional climate model and address outstanding questions regarding the role of agroecosystems in modulating regional climate. Here, we analyze dynamic crop growth in WRF across three simulated spatial scales (25km, 5km, and 1km) for growing seasons with precipitation above (2010), below (2012), and approximately equal (2015) to the seasonal average. Including dynamic crop growth in WRF significantly reduces biases in simulated leaf area index over croplands in the central U.S. relative to observations. However, there is no substantial difference in calculated daily evapotranspiration, average growing season temperature, or total growing season precipitation between WRF simulations with dynamic crops (WRF-Crop) compared to the dynamic vegetation module without crops (WRF-DV). Simulated corn (soy) mean absolute error (MAE), as a percentage of observed annual average yield, ranges from 24.7% -101% (28.1% - 109%) depending on year and spatial resolution, with the most significant biases in highly irrigated counties. Forcing Noah-MP-Crop with observed climate substantially reduces the range of corn (soy) yield MAE to 9.5% - 55.1% (15.0% - 37.5). Increased model resolution consistently leads to lower corn and soy yield estimates within WRF-Crop.
Numerical study of a scramjet engine flow field

A computer program has been developed to analyze the turbulent reacting flow field in a two-dimensional scramjet engine configuration. The program numerically solves the full two-dimensional Navier-Stokes and species equations in the engine inlet and combustor, allowing consideration of flow separation and possible inlet-combustor interactions. The current work represents an intermediate step towards development of a three-dimensional program to analyze actual scramjet engine flow fields. Results from the current program are presented that predict the flow field for two inlet-combustor configurations, and comparisons of the program with experiment are given to allow assessment of the modeling that is employed.
Heterogeneous System Model for Security in E-Health Applications

With medical devices and Internet-of-Things (IoT) becoming increasingly connected, e-health applications have been widely developing. However, security of both sensitive health information and critical device settings is a significant concern. Due to the intrinsic limitations of many medical devices, including low power and limited computational resources, security and device performance can be difficult to balance - especially for implanted devices, as implanted devices require a surgical procedure to replace the device or battery. In this work we propose a system model for e-health applications with consideration of heterogeneous medical devices, in terms of battery capacity and computational ability. In addition, different attacks are considered in the proposed system model. A case study is presented to show that the proposed system model can support heterogeneous medical devices with varying power and resource constraints. The case study demonstrates that it is possible to significantly reduce the overhead for security on power-constrained devices based on the proposed system model.
Examination of the Adult Brachial Plexus Patient

The exam of the adult brachial plexus is key in the localization of the extent of injury as well as determining if the nerve injury is spontaneously recovering. Conventions of manual muscle grading, measurement of range of motion, evaluation of the patient by observation, and methods of examination are detailed in this chapter.
Polymers in Tissue Engineering

The landscape of polymer selection and processing techniques is constantly evolving in the field of tissue engineering and regenerative medicine. This chapter will cover new advances in polymers that are used to regenerate functional tissues used to repair or replace tissues lost to age, disease, injury, or congenital defect. The focus will be on new processing techniques and the incorporation of biologics or drug delivery to enhance cellular response and ingrowth into the polymers that will create a more functional tissue replacement by engineering the polymer tissue interface. Special emphasis is placed on new frontiers in tissue engineering the lung and liver.
Signal transduction by protease-activated receptors

The family of G protein-coupled receptors (GPCRs) constitutes the largest class of signalling receptors in the human genome, controlling vast physiological responses and are the target of many drugs. After activation, GPCRs are rapidly desensitized by phosphorylation and β-arrestin binding. Most classic GPCRs are internalized through a clathrin, dynamin and β-arrestin-dependent pathway and then recycled back to the cell surface or sorted to lysosomes for degradation. Given the vast number and diversity of GPCRs, different mechanisms are likely to exist to precisely regulate the magnitude, duration and spatial aspects of receptor signalling. The G protein-coupled protease-activated receptors (PARs) provide elegant examples of GPCRs that are regulated by distinct desensitization and endocytic sorting mechanisms, processes that are critically important for the spatial and temporal fidelity of PAR signalling. PARs are irreversibly activated through proteolytic cleavage and transmit cellular responses to extracellular proteases. Activated PAR1 internalizes through a clathrin- and dynamin-dependent pathway independent of β-arrestins. Interestingly, PAR1 is basally ubiquitinated and deubiquitinated after activation and traffics from endosomes to lysosomes independent of ubiquitination. In contrast, β-arrestins mediate activated PAR2 internalization and function as scaffolds that promote signalling from endocytic vesicles. Moreover, activated PAR2 is modified with ubiquitin, which facilitates lysosomal degradation. Activated PARs also adopt distinct active conformations that signal to diverse effectors and are likely regulated by different mechanisms. Thus, the identification of the molecular machinery important for PAR signal regulation will enable the development of new strategies to manipulate receptor signalling and will provide novel targets for the development of drugs.
Critical role of cerebellar fastigial nucleus in programming sequences of saccades

The cerebellum plays an important role in programming accurate saccades. Cerebellar lesions affecting the ocular motor region of the fastigial nucleus (FOR) cause saccadic hypermetria; however, if a second target is presented before a saccade can be initiated (double-step paradigm), saccade hypermetria may be decreased. We tested the hypothesis that the cerebellum, especially FOR, plays a pivotal role in programming sequences of saccades. We studied patients with saccadic hypermetria because of either genetic cerebellar ataxia or surgical lesions affecting FOR and confirmed that the gain of initial saccades made to double-step stimuli was reduced compared with the gain of saccades to single target jumps. Based on measurements of the intersaccadic interval, we found that the ability to perform parallel processing of saccades was reduced or absent in all of our patients with cerebellar disease. Our results support the crucial role of the cerebellum, especially FOR, in programming sequences of saccades.
Presenting intuitive deductions via symmetric simplification

In automated deduction systems that are intended for human use, the presentation of a proof is no less important than its discovery. For most of today's automated theorem proving systems, this requires a non-trivial translation procedure to extract human-oriented deductions from machine-oriented proofs. Previously known translation procedures, though complete, tend to produce unintuitive deductions. One of the major flaws in such procedures is that too often the rule of indirect proof is used where the introduction of a lemma would result in a shorter and more intuitive proof.
Free Resources for Conducting Learning Sessions for Undergraduate Medical Students About Pharmaceutical Promotion

Pharmaceutical promotion has been shown in various studies to be an important influence on the prescribing behavior of doctors. Undergraduate students should be aware of promotion, be introduced to various tactics adopted by the industry and be able to respond to promotion. A survey conducted in 2004 showed most medical schools devoted only one to two hours of curriculum time to this topic. A number of free internet resources are available for faculty members interested in conducting sessions on this topic for students. This article discusses selected resources including the Ethical criteria for medicinal drug promotion, Understanding and responding to pharmaceutical promotion a practical guide, Healthy Skepticism website, Pharmedout website, No free lunch website, the website of the Citizen's Commission for Human Rights, the book Drug promotion: What we know, what we have yet to learn and resources dealing with disease mongering.
Raw Glycerol as an Alternative Carbon Source for Cultivation of Exopolysaccharide-Producing Bacteria

The large-scale use of biodiesel has shown significant environmental benefits as regards the reduction of global warming impacts. The increased generation of glycerol, the main byproduct of the reaction, makes necessary to propose alternatives to its use. In this context, the aim of this study was to evaluate raw glycerol (RG), a byproduct from biodiesel synthesis, as a carbon source for the cultivation of bacteria recognized as exopolysaccharides (EPSs) producers, compared with sucrose (S) and with a mixture of both components in a ratio of 1:1 w:w (SRG). The bacteria used were: Xanthomonas campestris pv. mangiferaeindicae IBSBF 1230, Pseudomonas oleovorans NRRL B-14683, Sphingomonas capsulata NRRL B-4261 and Zymomonas mobilis NRRL B-4286. All bacteria were capable of growing and producing EPSs using RG as the sole carbon source. For X . campestris , EPSs concentration of around 4.00 g L -1 was found for the different carbon sources tested. For P. oleovorans , only the medium composed by S (0.85 g L -1 ) differed from the other media, with better results being found using RG and SRG. S. capsulata showed higher concentration in the medium containing S and SRG, around 3.40 g L -1 , and in the medium containing RG this value decreased to 1.70 g L -1 . Z. mobilis , on the other hand, showed a better result using SRG (1.41 g L -1 ), and in the medium containing S and RG, these values were lower, reaching 0.27 and 0.77 g L -1 , respectively.
Multi-tier regulation of the streptomycete morphogenetic peptide SapB.

Summary Streptomyces coelicolor is a morphologically complex bacterium requiring the secretion of surface-active proteins to progress through its life cycle. SapB represents an important class of these biosurfactants, as illustrated by its ability to restore aerial hyphae formation when applied exogenously to developmental mutants. However, such aerial hyphae fail to sporulate, exemplifying the need to co-ordinate the timing of SapB production with other developmental events. SapB has an unusual lantibiotic structure. Its structural gene, ramS, is only 38 nucleotides downstream of the gene encoding its putative modification enzyme, RamC. Transient, co-ordinated expression of the operon was thought to be controlled by the response regulator RamR. However, we show that ramS is transcribed throughout the cell cycle with a dual expression profile dissimilar to the tightly controlled ramC expression. Surprisingly, post-translational modification relies on prior membrane localization of the precursor peptide, RamS, as demonstrated by the absence of RamS modification in S. coelicolor hyphae treated with the Bacillus subtilis lipoprotein surfactin. Our results demonstrate that interspecies interaction can also be mediated by interference of post-translational events. Further, temporal and spatial regulation of irreversible post-translational modification of a surface-active morphogenetic peptide suggests a new model for the control of key developmental events.
Blood Flow and Venous pH of Tissue-isolated Walker 256 Carcinoma during Hyperglycemia

Hemodynamic (blood flow rate, hematocrit, hemoglobin concentration, and blood viscosity) and pH responses to glucose (6 g/kg, i.p.) injections were studied in ten Walker 256 carcinoma tumors (0.5–1.8 g) grown in the “tissue-isolated” tumor preparation. A maximum blood flow reduction of 57 ± 19% (SD) occurred concurrently with an increase in tumor arterial-venous blood pH difference 20–30 min after glucose administration. Tumor venous blood pH dropped significantly by 0.15 ± 0.07 pH unit to 7.15 ± 0.01, while systemic blood pH dropped by 0.06 ± 0.02 pH unit to 7.38 ± 0.03. Arteriovenous blood pH differences were found to correlate with blood flow rates; however, both the small magnitude of the pH reduction and the immediate blood flow response argue against the hypothesis of increased resistance to flow caused by low pH-stiffened RBC membranes. Significant increases in systemic and tumor efferent whole blood viscosities at 2.25 and 4.5s-1 occurred after glucose administration, while hemoglobin concentrations of systemic and tumor efferent blood increased by as much as 11 ± 1 and 16 ± 2%, respectively. Venous to arterial hematocrit and hemoglobin ratios remained unchanged with glucose administration. These data suggest local tumor blood flow reductions are caused by increased viscous resistance to flow within the tortuous microvasculature of tumor, not as a result of low pH RBC rigidity, but rather from other mechanisms such as glucose-mediated RBC rigidity and systemic hemoconcentration.
Review of geochemical reference sample programs since G-1 and W-1: progress to date and remaining challenges

Abstract A brief history of programs to develop geochemical reference samples and certified reference samples for use in geochemical analysis is presented. While progress has been made since G-1 and W-1 were issued, many challenges remain.
On the Role of Formal Methods in Software Certification: An Experience Report

This paper describes how formal methods were used to produce evidence in a certification, based on the Common Criteria, of a security-critical software system. The evidence included a top level specification (TLS) of the security-relevant software behavior, a formal statement of the required security properties, proofs that the specification satisfied the properties, and a demonstration that the source code, which had been annotated with preconditions and postconditions, was a refinement of the TLS. The paper also describes those aspects of our approach which were most effective and research that could significantly increase the effectiveness of formal methods in software certification.
Better backtracking support for programmers

Programmers often need to backtrack while coding, yet there is only limited support for backtracking in modern programming tools. Our study results confirmed the prevalence of backtracking and identified several problems programmers face while backtracking. To mitigate these problems, we are building an IDE plug-in aimed at providing better support for backtracking by combining a selective undo mechanism, novel visualizations, and code change history search features. We envision that this approach will help programmers perform backtracking tasks more easily.
The effect of dibutyl phthalate (DBP) plasticizer on the stability of optical properties of polystyrene (PS) after exposure to gamma radiation

Abstract The objective of this work was to study the effect of gamma radiation on the UV-visible transmission properties of PS/DBP solutions in the range containing 0–25wt% of DBP. Samples were prepared by bulk-polymerizing styrene in the presence of DBP. Transmission spectra before and at intervals after irradiation were characterized with a Hewlett-Packard 8452A diode array spectrophotometer. Glass transition temperatures were determined by a Du Pont 2910 DSC. Radiation-induced losses in transparency decreased as the glass transition temperatures decreased. Glass transition temperatures were unchanged by irradiation. GPC studies were conducted in filtered samples using a Polymer Laboratories PL gel 10-μm mixed-bed column. Molecular-weight distributions were broad, but decreased after irradiation. Number-average molecular weights increased after irradiation. Radiation damage is discussed in terms of the effect of matrix mobility on recoverable losses in transparency.
Rituximab Inhibits the In Vivo Primary and Secondary Antibody Response to a Neoantigen, Bacteriophage phiX174

The response to primary immunization in patients treated with Rituximab (RIT) is not clear. We studied the in vivo antibody response of chronic renal failure (CRF) patients to the neoantigen bacteriophage phiX174 given alone or after ablation with RIT. Eighteen CRF subjects received two immunizations with phiX174 separated by 6 weeks. Nine subjects received a single dose of RIT. The intensity and immunoglobulin isotype of the antibody response (K(v)) were measured post-infusion. In addition, three subjects previously immunized and treated with RIT underwent a third and fourth immunization with phiX174 and a tetanus control 2 years later. RIT significantly decreased peak K(v) responses when compared to both historic non-CRF controls and to CRF subjects. CRF itself decreased peak K(v) responses compared to non-CRF controls. Percent-ratio of anti-phage IgM to IgG was significantly decreased in RIT treated subjects. One of three subjects treated with RIT was found to have developed a partial B cell tolerance to phiX174 administration 2 years later. RIT decreases antibody production and isotype switching to neoantigens and might be useful to prevent antibody response to therapeutic drugs and to newly transplanted organs.
Neutron Diffraction by Paramagnetic and Antiferromagnetic Substances

Neutron scattering and diffraction studies on a series of paramagnetic and antiferromagnetic substances are reported in the present paper. The paramagnetic diffuse scattering predicted by Halpern and Johnson has been studied, resulting in the determination of the magnetic form factor for ${\mathrm{Mn}}^{++}$ ions. From the form factor, the radial distribution of the electrons in the $3d$-shell of ${\mathrm{Mn}}^{++}$ has been determined, and this is compared with a theoretical distribution of Dancoff. Antiferromagnetic substances are shown to produce strong, coherent scattering effects in the diffraction pattern. The antiferromagnetic reflections have been used to determine the magnetic structure of the material below the antiferromagnetic Curie temperature. For some substances the magnetic unit cell is found to be larger than the chemical unit cell. The temperature dependence of the antiferromagnetic intensities has been studied, and the directional effects which characterize neutron scattering by aligned atomic moments have been used to determine the moment alignment with respect to crystallographic axes. From studies with magnetic ions possessing both orbital and spin moments, it is found that the antiferromagnetic intensities contain partial orbital moment components along with the spin moment component. The degree of orbital moment contribution agrees satisfactorily with that predicted by models of lattice quenching.
Wielding the green stick: criminal enforcement at the EPA under the Bush and Obama administrations

The criminal prosecution of environmental offenders by the US Environmental Protection Agency (EPA) is one of the agency’s most politicised yet poorly understood responsibilities. Through content analysis of the Agency’s criminal prosecutions in 2001–2011, we undertook analysis of nearly 1000 cases to understand better whether and how the outcomes of the criminal enforcement division change under presidential administrations. Using a principal-agent framework, our results suggest presidents do matter for enforcement outcomes. Yet, the more interesting conclusion is that these outcomes are not extremely divergent, suggesting that the Agency is able to navigate the often conflicting dictates of various political principals, under similar budgetary constraints, and in step with an Agency culture that values strong enforcement. Moreover, we find that such enforcement efforts are substantively valuable, as many of these cases involve serious and willful violations of law that result in significant harm to huma...
Electronic structure models, bonding and optical moments in amorphous and crystalline semiconductors

Abstract A deteiled comparison of moments of e2 for a variety of amorphous (a) semiconductors and closely related crystals (x) is presented as an example of a general methodology utilizing such moments as a probe of electronic structure and chemical bonding models. The moments 0 and 2 are found to be explicitly related within a one-electron approximation to average interband dipole and momentum matrix elements ( Q and P ). Although the scope of this study is limited by the availability of sufficiently extensive optical data, the present results strongly suggest that for nearly “ideal” amorphous samples Q a > Q x in simple tetrahedral semiconductors, Q a ≈ Q x in tetrahedral oxides, and Q a Q x in chain-like or layered semiconductors. In the materials considered here the differences in Q values are typically less than 15%. The validity of the “independent band” model and a more general real space analog are discussed using these results. Differences between Q a and Q x are shown to result from short-range disorder. The effects of such disorder are examined qualitatively. The result Q a > Q x in tetrahedral semiconductors is attributed to bond angle and dihedral angle fluctuations and the result Q a Q x in molecular semiconductors is attributed to reduced interactions between lone pair electrons.
TQM and CIM Can Work Together

ABSTRACTMultiple simultaneous change initiatives are, in general, more difficult to successfully implement than are individual change initiatives. Multiple initiatives, at a minimum, compete for scarce attention, time, and resources and often actually have conflicting objectives or employee behavior requirements. However, CIM and TQM complement each other and are best implemented together. Companies that currently lag behind their competitors in quality and CIM can implement both at the same time as a catch-up strategy.
An experimental study of the backscattering of 5.3-MeV alpha particles from platinum and monel metal

Abstract The angular and energy distribution of the α-particles backscattered from essentially weightless sources of polonium-210 deposited on platinum and on monel metal have been measured. It was found that the backscattering occurs only at angles close to the plane of the mounting, i.e. within 15°, and that the backscattered α-particles are distributed over the entire energy range. Numerical integration of the angular distribution gives 3.1 percent and 2.1 percent backscattering for platinum and monel, respectively.
‘Is’–‘Ought’ Derivations and Ethical Taxonomies

Hume seems to claim that there does not exist a valid argument that has all non-ethical sentences as premises and an ethical sentence as its conclusion. Starting with Prior, a number of counterexamples to this claim have been proposed. Unfortunately, all of these proposals are controversial. Even the most plausible have a premise that seems like it might be an ethical sentence or a conclusion that seems like it might be non-ethical. Since it is difficult to tell whether any of these counterexamples are genuine, we need a taxonomy that sorts out ethical sentences from non-ethical ones. We need to know the difference between an ‘Is’ and an ‘Ought’. In the first part of the paper, I establish the need for a taxonomy. I consider some of the most influential ‘Is’–‘Ought’ derivations. These include proposals by Prior and Searle. I argue that each proposal has a premise whose status as ethical or non-ethical is difficult to determine. In the second part of the paper, I consider taxonomies proposed by Karmo and Maitzen. I argue against both taxonomies. I end with the claim that we need a taxonomy of ethical sentences and that none of the current proposals are adequate.
Effect of Asymmetry on Bilayer Membrane Systems

Many biological processes, such as membrane fusion and the action of microbial proteins, involve asymmetric uptake of proteins. In addition, it has been demonstrated that large mechaosensitive channels open by the asymmetric inclusion of lyso-lipids in the bilayer in the absence of external pressure. These phenomena can be interpreted in terms of the asymmetric local pressure profile in the bilayer, which lacks the quantitative understanding. By noting that such asymmetric pressure profile can be induced in bilayer membranes with asymmetric number of lipids between leaflets, to provide quantitative understanding, we performed molecular dynamics simulations of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) bilayer membranes for a set of systems with different level of asymmetry with and without gramicidin A (gA) or WALP23. We observed that even highly asymmetric lipid bilayers with and without gA or WALP23 were stable during the whole simulation time, which is consistent with the previous study of dipalmitoyl-phosphatidylcholine (DPPC) bilayers [J. Am. Chem. Soc. 131, 15194 (2009)]. As the number of lipids in the lower leaflet becomes smaller, the lipids are more tightly packed in the top leaflet and less ordered in the bottom leaflet, which are quantified in terms the lateral pressure profile, the order parameter, the area per lipid, etc. However, the hydrophobic thickness for pure lipid bilayers does not show meaningful dependence on the asymmetry, which results from the stretched and less ordered lipids in the upper and lower leaflets, respectively. We will also discuss the influence of the asymmetry on the properties of protein-lipid interactions, such as the distance dependence of the lipid properties and the interaction patterns around gA or WALP23.
Detailed modeling of soot formation in laminar premixed ethylene flames at a pressure of 10 bar

Abstract Detailed modeling of soot particle nucleation, growth and oxidation in laminar premixed ethylene-air flames at a pressure of 10 bar is presented. The employed kinetic model of soot formation, developed and tested earlier for subatmospheric and atmospheric flames, can quantitatively describe the experimental soot volume fraction profiles collected in a number of ehtylene flames at high pressures. The kinetic model consists of initial aromatic ring formation from nonaromatic species, planar polycyclic aromatic hydrocarbon (PAH) growth through the hydrogen-abstraction-acetylene-addition reaction mechanism, particle nucleation through coalescence of PAHs, particle growth by coagulation and surface reactions of the forming clusters and particles, and particle oxidation. Analysis of the computational results obtained at 10 bar and additional tests performed for a 1-bar flame suggest that the influence of pressure on soot production arises mainly from the larger concentration of acetylene, which affects both the soot surface growth and the nucleation of soot particles.
Shear-thickening in suspensions, associating polymers, worm-like micelles, and poor polymer solutions

During the past year, major advances in our understanding of shear-thickening phenomena have occurred especially as the result of rheo-optical techniques and simulations. In suspensions, studies have found that shear-thickening is caused by cluster formation and is not necessarily due to an order→disorder transition; in associating polymer systems and poor polymer solutions, recent work has shown that shear-thickening-is related to the shear-induced formation of intermolecular structures.
Spreadsheets and databases—alternatives to programming for non-computer science majors

Microcomputers have become easier and easier to use an emphasis is placed on software design for users with little or no experience. With a minimal amount of training, students or employees can become productive. Yet, academic programs still teach programming as a fundamental part of computer literacy. This paper proposes that the programming portion of the class be eliminated and replaced with a study of spreadsheets and databases. The paper discusses the manner in which spreadsheet and database design can be approached to maximize learning.An important concept that is learned in any programming class is algorithm development. Students learn how to analyze the problem and to set up the step-by-step solution. This process must be done before any coding can begin. Spreadsheets offer the same type of learning and are much more appropriate for non-computer science majors. Students must formulate the problem, determine the equations and formulas necessary to solve it, and then set up the worksheet. Spreadsheet applications are found in every discipline and their design requires a minimal amount of computer knowledge and mathematics.Learning to set up a database and design the queries necessary to obtain information from the database is a concept important to computer literacy. Once again, students learn to “program” by learning to construct their questions in a manner that is meaningful to the software package.
Butylate hydroxytoluene pretreatment protects against cytotoxicity and reduces covalent binding of aflatoxin B1 in primary hepatocyte cultures

Primary cultures of adult rat hepatocytes were used to characterize the effect of butylated hydroxytoluene (BHT) pretreatment on the metabolic disposition and cytotoxicity of a single dose of aflatoxin B1 (AFB1). Four male Sprague-Dawley rats were fed a control diet, and five were fed a diet containing 0.5% BHT. After 10 days, hepatocytes were prepared and cultured in chemically defined, hormone-supplemented medium. After 20–22 hr in culture, 120–150 ng of [14C]aflatoxin B1 was added to dishes containing 2.5 × 106 cells. By 10 hr, control cells had converted 59% of the AFB1 to aqueous metabolites, while 15.5% was bound covalently. During the same interval, cells from BHT-fed rats produced 69% aqueous metabolites, and only 6.6% was bound covalently. The rate of AFB1 disappearance in the two groups was not statistically different. AFB1 produced marked cytotoxicity in hepatocyte cultures from control rats but had no apparent toxic effect on hepatocyte cultures from BHT-pretreated rats, as indicated by light microscopic examination and release of lactate dehydrogenase into the medium. These results suggest that reduction of cytotoxicity by BHT was associated with increased output of nontoxic, water-soluble metabolites and decreased binding of metabolites to macromolecules. These results also indicate that BHT may protect against the acute toxicity and carcinogenicity of aflatoxin B1 in vivo.
STARNET: a multiGbit/s optical local area network with both packet and circuit switching

The potential of passive star WDM networks is believed to be extremely high.1-3 STARNET is a new broadband optical LAN based on such physical structure. Every STARNET node supports both packet traffic and a high-speed WDM circuit interconnect, simultaneously and independently. As a result, STARNET carries diverse types of traffic (i.e., bursty and continuous, low-speed and broadband) in an efficient way. Each node requires only two lasers and its structure permits frequency stabilization of the whole network. An experimental four-node, 12-Gbit/s (3-Gbit/s per node) FDDI-compatible (at the packet network level) STARNET is being built at Stanford University.
Pathways of n-aminopyrrole synthesis

Abstract Acid-catalyzed condensation of tosylhydrazine with 2,5-diethoxytetrahydrofuran yielded, in addition to N-tosylamidopyrrole, the bistosylhydrazone of succindialdehyde and two hydropyridazine derivatives; the composition of the product was highly dependent upon the choice of reaction conditions. On the basis of chemical and spectral evidence structures were established for all of these compounds, and their interconversions were studied.
Adaptive Seeding: A New Method for Simulating Biologically Relevant Timescales

Molecular Dynamics (MD) simulations may complement experiments by allowing the evolution of molecular systems to be monitored with atomic resolution. However, it is currently only possible to simulate a few dozen nanoseconds of molecular dynamics in a month whereas most biologically relevant processes on the molecular scale take a few microseconds, or even seconds. Simulating a microsecond would take about a year so the utility of MD is limited. Our new adaptive seeding method, on the other hand, is able to completely sample processes that take tens of microseconds experimentally in a single week. This is accomplished by using short non-equilibrium simulations to identify the dominant thermodynamic states of the system. New simulations are then started from each state in a process called seeding and these simulations are found to give equilibrium sampling. We can then predict experimental observables like folding free energies and explain the chemical details underlying processes like folding. We have applied the adaptive seeding method to a small RNA system that folds in about ten microseconds. One set of simulations was started from the folded state determined by NMR while another was started from a random coil. The models obtained from each set of simulations agree within error and, therefore, represent the true equilibrium distribution of the molecule.
BONE MORPHOGENETIC PROTEIN 2 (BMP-2) ENHANCES BMP-3, BMP-4, AND BONE CELL DIFFERENTIATION MARKER GENE EXPRESSION DURING THE INDUCTION OF MINERALIZED BONE MATRIX FORMATION IN CULTURES OF FETAL RAT CALVARIAL OSTEOBLASTS

Normal bone formation is a prolonged process that is carefully regulated and involves sequential expression of growth regulatory factors by osteoblasts as they proliferate and ultimately differentiate. Since this orderly sequence of gene expression by osteoblasts suggests a cascade effect, and BMP-2 is capable of initiating and maintaining this effect, we examined the effects of BMP-2 on expression of other BMPs and compared these effects with the expression pattern of bone cell differentiation marker genes in primary cultures of fetal rat calvarial (FRC) osteoblasts. To examine the gene expression profile during bone cell differentiation and bone formation, we also examined the effects of rBMP-2 on bone formation in vivo and in vitro. rBMP-2 stimulated bone formation on the periosteal surface of mice when 500 ng/day rBMP-2 was injected subcutaneously. When rBMP-2 was added to primary cultures of FRC osteoblasts, it accelerated mineralized nodule formation in a time and concentration-dependent manner (10–40 ng/ml). rBMP-2 (40 ng/ml) enhanced BMP-3 and -4 mRNA expression during the mineralization phase of primary cultures of FRC osteoblasts. Enhancement of BMP-3 and -4 mRNA expression by rBMP-2 was associated with increased expression of bone cell differentiation marker genes, alkaline phosphatase (ALP), type I collagen, osteocalcin (OC), osteopontin (OP), and bone sialoprotein (BSP). These results suggest that BMP-2 enhances expression of other BMP genes during bone cell differentiation. BMP-2 may act in a paracrine fashion in concert with other BMPs it induces to stimulate bone cell differentiation and bone formation during remodeling.
Non-aqueous polypyrrole colloids: Synthesis and characterization

Abstract The preparation of sterically-stabilized polypyrrole colloids via a dispersion polymerization route in non-aqueous media is described for the first time. Pyrrole polymerization was achieved using FeCl 3 as an oxidant/dopant in organic solvents such as methyl acetate, methyl formate and propyl formate. Macroscopic precipitation was prevented by the use of poly(vinyl acetate) as a polymeric surfactant. Various other surfactants were ineffective and consequently resulted in precipitation of polypyrrole. Several techniques were used for characterization of the dispersions including transmission and scanning electron microscopies (TEM and SEM), thermogravimetric analysis (TGA), charge velocity analysis and visible absorption spectroscopy. TEM indicated a polydisperse spherical morphology with a particle diameter in the range 100–300 nm. The compressed pellet conductivities of the dried dispersion were as high as 0.1 S/cm. These dispersions are often compared with bulk and colloidal polypyrrole prepared in aqueous media.
Differentiating malignant hypertension-induced thrombotic microangiopathy from thrombotic thrombocytopenic purpura.

Objectives:Malignant hypertension can cause thrombotic microangiopathy (TMA) and the overall presentation may mimic thrombotic thrombocytopenic purpura (TTP). This presents a dilemma of whether or ...
The Behavior of Thrust Washer Bearings Considering Mixed Lubrication and Asperity Contact

The behavior and life of a tilted flat thrust washer bearing is modeled by a comprehensive numerical code. The goal is to investigate the conditions that distress thrust washer bearings through numerical techniques. The thrust washer bearing supports non-axisymmetric loads within the planetary gear sets of automatic transmissions and consists of flat-faced washers placed between an idle helical gear and its contacting face. Because of non-axisymmetric loading, the gears and washers tilt in relation to the carrier, forming a converging gap that may produce hydrodynamic lift. Various coupled numerical schemes model sliding friction, boundary lubrication, asperity contact, thermo-viscous effects, and full film lubrication. The model provides predictions of frictional torque, bearing temperature, hydrodynamic lift, and other indicators of bearing performance. The results show that the bearing operates in the regimes of boundary lubrication, mixed lubrication, and full-film lubrication, and that the bearing ca...
TU-C-17A-05: Dose Domain Optimization of MLC Leaf Patterns for Highly Complicated 4Ï€ IMRT Plans

Purpose: Highly conformal non-coplanar 4π radiotherapy plans typically require more than 20 intensity-modulated fields to deliver. A novel method to calculate multileaf collimator (MLC) leaf patterns is introduced to maximize delivery efficiency, accuracy and plan quality. Methods: 4 GBM patients, with a prescription dose of 59.4 Gy or 60 Gy, were evaluated using the 4π algorithm using 20 beams. The MLC calculation utilized a least square minimization of the dose distribution, with an anisotropic total variation regularization term to encourage piecewise continuity in the fluence maps. Transforming the fluence to the dose domain required multiplying the fluence with a sparse matrix. Exploiting this property made it feasible to solve the problem using CVX, a MATLAB-based convex modeling framework. The fluence was stratified into even step sizes, and the MLC segments, limited to 300, were calculated. The patients studied were replanned using Eclipse with the same beam angles. Results: Compared to the original 4π plan, the stratified 4π plan increased the maximum/mean dose for, in Gy, by 1.0/0.0 (brainstem), 0.5/0.2 (chiasm), 0.0/0.0 (spinal cord), 1.9/0.3 (L eye), 0.7/0.2 (R eye), 0.4/0.4 (L lens), 0.3/0.3 (R lens), 1.0/0.8 (L Optical Nerve), 0.5/0.3 (R Optical Nerve), 0.3/0.2 (L Cochlea), 0.1/0.1 (R Cochlea), 4.6/0.2 (brain), 2.4/0.1 (brain-PTV), 5.1/0.9 (PTV). Compared to Eclipse, which generated an average of 607 segments, the stratified plan reduced (−) or increased (+) the maximum/mean dose, in Gy, by −10.2/−4.1 (brainstem), −10.5/−8.9 (chiasm), +0.0/−0.1 (spinal cord), −4.9/−3.4 (L eye), −4.1/−2.5 (R eye), −2.8/−2.7 (L lens), −2.1/−1.9 (R lens), −7.6/−6.5 (L Optical Nerve), −8.9/−6.1 (R Optical Nerve), −1.3/−1.9 (L Cochlea), −1.8/−1.8 (R Cochlea), +1.7/−2.1 (brain), +3.2/−2.6 (brain-PTV), +1.8/+0.3 Gy (PTV. The stratified plan was also more homogeneous in the PTV. Conclusion: This novel solver can transform complicated fluence maps into significantly fewer deliverable MLC segments than the commercial system while achieving superior dosimetry. Funding support partially contributed by Varian.
Timing of referral for vascular access placement: A systematic review

Objective This review was conducted to determine the optimal timing for referring patients with end-stage renal disease to vascular surgery for access placement. Methods A systematic review of the electronic databases (MEDLINE, EMBASE, Current Contents, Cochrane CENTRAL and Web of Science) was conducted through March 2007. Randomized and observational studies were eligible if they compared an early referral cohort with a late referral cohort in terms of patient-important outcomes such as death, access-related sepsis, and hospitalization related to access complications. Results We found no studies that fulfilled eligibility criteria. Conclusion At the present time, the optimal timing for referral to vascular surgery for vascular access placement is based on expert opinion and choices made by patients and physicians.
Prediction of drug concentration-time profiles of therapeutic proteins in humans from animals

The main objective of this work is to evaluate two methods to predict concentration-time profiles of therapeutic proteins in humans in a multi-compartment system using animal pharmacokinetic parameters. The prediction of concentration-time profiles in humans in a multi-compartment system was based on two proposed methods (volumes of distribution and pharmacokinetic constants) of Mordenti. Seven protein drugs (5 monoclonal antibodies, one epoetin, and one thrombin inhibitor) from the literature were chosen that were described by two-compartment model in both humans and animals. Two- compartment model parameters (CL, Vc, Vss, Vβ, α, A, β and B) at least from 3 animals were scaled to humans and then were used to predict plasma concentrations-time profiles in humans. The results showed that both the methods provided almost similar concentration-time profiles for most of the drugs. It appears that the proposed methods of Mordenti can be used for reasonably accurate prediction of concentration-time profiles of ...
Structural stability of BTTB-based metal–organic frameworks under humid conditions

Stability of metal–organic frameworks (MOFs) under humid environments is of particular interest for their potential commercial and industrial uses. In this work, water vapor adsorption experiments and subsequent structural analysis on the newly synthesized BTTB-based MOFs (BTTB = 4,4′,4′′,4′′′-benzene-1,2,4,5-tetrayltetrabenzoic acid) have been performed to investigate their stability under humid conditions. ZnBTTB and CdBTTB degrade completely after exposure to 90% relative humidity (RH). The instability of ZnBTTB is due to the four-coordinated zinc carboxylate system similar to MOF-5. Similarly, CdBTTB is also unstable as Cd2+ ions have coordination number of 4 when the MOF is activated (desolvated). Unlike ZnBTTB and CdBTTB, the structure of ZnBTTBBDC has not degraded significantly upon exposure to 90% RH. This partial structure retention is attributed to the higher nuclearity of metal in the SBU of ZnBTTBBDC and higher metal coordination number compared to ZnBTTB and CdBTTB. Water adsorption isotherms of CoBTTBAZPY and ZnBTTBAZPY show type V behavior due to free nitrogen sites. The crystal structures of AZPY-based pillared MOFs show partial loss of crystallinity whereas BPY-based pillared MOFs remain stable after exposure to 90% RH. The greater stability of BPY-based MOFs is attributed to the higher extent of catenation, higher rigidity of the BPY linker, and absence of any hydrophilic sites.
“Changing men” and feminist politics in the United States

In recent years, U.S. men have responded to and at times initiated changes in the personal and social relations of gender. There is an increasing cultural preoccupation with men's roles as fathers.1 Gay liberationists and anti-sexist men are confronting heterosexism and male domination in society,2 while some academic men contribute to the feminist challenge to phallocentric curricula.3 Meanwhile, born-again Christians are subtly re-defining women's and men's "god-given roles,"4 while conservative ministers hold popular seminars on "the meaning of manhood,"5 and angry men (mostly divorced fathers) organize for "men's rights."6 And as I write, Robert Bly's book, Iron John: A Book About Men7 enjoyed over half a year on the national top ten bestsellers list.
Thomas Forrest's Pseudonym in The Disappointment

Although critics generally agree that Thomas Forrest wrote The Disappointment; or, the Force of Credulity (1767; rev. ed. 1796), no one has explained the significance of his pseudonym, Andrew Barton. Were the play typical of early American drama, the matter of authorship would be relatively unimportant; but because The Disappointment has historical, cultural and literary value, the pseudonym deserves attention.
Methylation of fatty acids in a methionine-dependent Agrobacterium tumefaciens controlled with exogenous methionine.

Abstract 14 C-transmethylation to form the cyclopropane and branched-chain fatty acids occurred linearly without a lag if exogenous [ ME - 14 C]methionine was pulsed late in the stationary growth phase. With chemostatic cultures (specific dilution rate of 0.03 h −1 ) of a methionine-dependent Agrobacterium tumefaciens (strain WM-11), synthesis of only the cyclopropanes was controlled by an excess of exogenous methionine with a restricting concentration of sucrose. When exogenous methionine was a limiting growth factor, cyclopropane fatty acids were not formed and mono-unsaturated fatty acids accumulated to a maximal amount. A methyl-branched fatty acid presumed to be [ 14 C]methylstearic acid (Me-C 18 ) was also found when excess methionine was present in batch cultures with low aeration. In addition to the specific 14 C-methylation, the “methylstearic” acid was identical in its gas-liquid Chromatographie property to a reference Me-C 18 compound. The reference Me-C 18 was prepared from the PtO 2 -hydrogenation of C 19 cyclopropane acid (dihydrosterculic). Since the “methylstearic” acid was detected in aged cells of static cultures, a biological transmethylation-hydrogenation was suggested.
Keratinocyte growth factor ameliorates mucosal injury in an experimental model of colitis in rats

Abstract BACKGROUND & AIMS: Keratinocyte growth factor (KGF) is known to enhance tissue repair in the skin; however, its role in the gastrointestinal tract is largely unknown. The aim of this study was to evaluate the effects of exogenous KGF in an experimental model of colitis in rats. METHODS: KGF was administered before or after induction of colitis with 2,4,6-trinitrobenzenesulfonic acid/ethanol. In the first two study groups, KGF (5 mg/kg) was administered intraperitoneally 24 hours and 1 hour before induction of colitis; animals were killed 8 hours (n=10) and 1 week (n=10) after injury. In subsequent study groups, KGF or vehicle treatment was begun 24 hours after the induction of colitis at doses of 5 (n=20), 1 (n=10), and 0.1 (n=10) mg/kg intraperitoneally and continued once daily for 1 week. Colonic tissue samples were evaluated macroscopically and microscopically for mucosal injury and assayed for myeloperoxidase activity. RESULTS: Administration of KGF after but not before induction of colitis significantly ameliorated tissue damage. Macroscopic necrosis and microscopic ulcerations were reduced by 40%- 50% at KGF doses of 1 and 5 mg/kg. CONCLUSIONS: Exogenous KGF has a key role in mucosal healing in an experimental model of colitis in rats. (Gastroenterology 1996 Apr;110(4):1077-83)