cssi/SciSciGPT-SciSciNet huggingface dataset:
Polar-on-nonpolar epitaxy

Abstract One of the most fundamental problems that must be solved if device-quality GaAs is to be grown on Si substrates is that of suppressing antiphase disorder. Recent experimental evidence shows that such disorder can be suppressed not only on the (211) orientation, but also on (100), contrary to earlier theoretical expectations. A detailed discussion is given of the mechanism by which this suppression takes place, through a combination of slight misorientation and a high-temperature surface anneal, which lead to the pairing of all Si surface steps into a particular kind of double-height steps. A recent model by Aspnes and Ihm explains the energetic preference for this kind of step by postulating a drastic reconstruction of the atomic configuration at the step edge through the formation of a π-bonded chain running along the step. Another unexpected puzzle is posed by the recent observation that on a given Si(100) surface antiphase disorder-free growth with both possible Ga—As sublattice allocations can be achieved, depending on initial nucleation conditions. A new detailed nucleation model is proposed that explains these observations, by drawing heavily on earlier considerations of Harrison et al. concerning the electrostatics of a polar-nonpolar interface.
Diabetic nephropathy: the proteinuria hypothesis.

Background/Aims: Proteinuria, nearly a universal finding in progressive kidney disease, has been the subject of frequent recent analyses in the renal literature. Proteinuria is a ha
Numerically stable fluid-structure interactions between compressible flow and solid structures

We propose a novel method to implicitly two-way couple Eulerian compressible flow to volumetric Lagrangian solids. The method works for both deformable and rigid solids and for arbitrary equations of state. The method exploits the formulation of [11] which solves compressible fluid in a semi-implicit manner, solving for the advection part explicitly and then correcting the intermediate state to time t^n^+^1 using an implicit pressure, obtained by solving a modified Poisson system. Similar to previous fluid-structure interaction methods, we apply pressure forces to the solid and enforce a velocity boundary condition on the fluid in order to satisfy a no-slip constraint. Unlike previous methods, however, we apply these coupled interactions implicitly by adding the constraint to the pressure system and combining it with any implicit solid forces in order to obtain a strongly coupled, symmetric indefinite system (similar to [17], which only handles incompressible flow). We also show that, under a few reasonable assumptions, this system can be made symmetric positive-definite by following the methodology of [16]. Because our method handles the fluid-structure interactions implicitly, we avoid introducing any new time step restrictions and obtain stable results even for high density-to-mass ratios, where explicit methods struggle or fail. We exactly conserve momentum and kinetic energy (thermal fluid-structure interactions are not considered) at the fluid-structure interface, and hence naturally handle highly non-linear phenomenon such as shocks, contacts and rarefactions.
A new technique to measure the etch rate of mica

Abstract We have developed a new technique for measuring the general etch rate of mica in hydrofluoric acid. A laser interferometer is used to monitor the thickness of the sample as it etches. This technique can be extended to other materials and etchants.
Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.
Calorimetric determination of the heat of reaction of solid tris(hydroxymethyl)aminomethane with 0.1 M HCl solutions at 10, 25 and 40°c

Abstract The heat of reaction of solid tris(hydroxymethyl)aminomethane (THAM) with 0.1 M hydrochloric acid solution has been determined calorimetrically at 10, 25, and 40°C. The experimental conditions suggested by the Standards Committee of the U.S. Calorimetry Conference were followed. Values of Δ H ° of −7.644±0.014, −7.104± 0.008, and −6.555±0.012 kcal/mole at 10, 25, and 40°C, respectively, are reported. Results of the study are compared with those of other workers, and THAM is recommended for use as an interlaboratory comparison standard for solution calorimetry.
Dynamic preferences and specialized tastes

Abstract A dynamic preference model suggests why people may develop specialized tastes as they age, why initially similar people may develop different specializations, and why socially related people, even if initially dissimilar, may develop the same specializations.
Methylation patterns of HLA-DR alpha genes in six mononuclear cell lines.

The relationship between DNA methylation and HLA-DRα gene expression was investigated in six mononuclear cell lines. RPMI-4265 (B cell) and HUT-78 (T cell) constitutively express HLA-DR. HL-60 (myelomonocyte) and U-937 (monocyte) can be induced to express HLA-DR. Jurkat and Molt-4 (T cells) do not and cannot be induced to express HLA-DR. Based on the known nucleotide sequence of the HLA-DRα gene, methylation-sensitive restriction endonucleases Msp I, Hpa II, Hha I, Ava I, Hae II, and Sma I were used to detect the CpG methylation in three regions of the HLA-DRα gene: (1) the 5′flanking region, (2) the exon 1 region, and (3) the coding region containing exons 2, 3, 4, and 5. This precise mapping of CpG methylation yielded no correlation between DNA hypomethylation and HLA-DRα gene expression. In all cell lines, exon 1 region is hypomethylated, whereas 5′ and coding regions are hypermethylated. Whereas hypermethylation of the coding region does not block transcription, hypomethylation of the exon 1 region may be essential but is clearly not sufficient for HLA-DRα gene transcription. This exon 1 region demethylation may result in an open (deoxyribonuclease I hypersensitive) chromatin conformation around the promoter where trans-acting regulatory factors presumably bind and initiate HLA-DRα transcription. In the course of this study, a novel Msp I polymorphism in the intron 1 of the HLA-DRα, gene was found.
Discussion of “Case Study: Numerical Evaluation of Hydraulic Transients in a Combined Sewer Overflow Tunnel System” by M. Politano, A. J. Odgaard, and W. Klecan

The discussers would like to congratulate the authors for a very interesting paper, in which the gradual flow regime transition i.e., in the absence of a pipe-filling bore front —an outstanding issue in interface tracking models for flow regime transition—was addressed. The proposed model is in this regard an improvement on the family of models presented by Song et al. 1983 and Cardle and Song 1988 , among others. Based on the discussers’ experience in modeling tunnel systems, gradual-flow regime transitions should probably be more common than pipe-filling bores, even though some extreme inflow conditions, which could be very important for design purposes, may require pipe-filling bore modeling. The discussers would like to make a few comments and raise some issues: 1. Geysering events are not necessarily characterized solely by water jets, as investigated by Vasconcelos 2005 . Experiments and field evidence indicate that such phenomena could also be triggered by air pocket expulsion through water-filled vertical shafts in stormwater systems. Careful consideration of the air pocket entrapment is required when dealing with flow-regime transition events. 2. There is already available an alternative to model flowregime transition other than Preissmann slot or interface tracking-based models, namely the TPA model of Vasconcelos et al. 2006 . The TPA model overcomes the limitations of Preissmann-slot models of modeling subatmospheric flows, while retaining a single set of equations to simulate both free-surface and pressurized flows. Indeed as the authors mentioned, flow-regime transition models constructed with shock-capturing approaches may develop numerical oscillations in the vicinity of pipe-filling bores. However, Vasconcelos et al. 2006 propose an approach to attenuate such oscillations. More recently, Vasconcelos et al. 2009 address this issue, and other techniques to attenuate these numerical oscillations are proposed. 3. The discussers doubt that the proposed model would be able to handle a depressurization scenario in which pressurized flows are succeeded by free-surface flows. In such cases, the flow regime interface would be characterized by air intrusion
Welfare analysis of alternative patent policies for software innovations

We present a duopoly model that extends existing patent policy design models in the economics literature to formalize the links among the patent policy levers set by public policy (patent height and width), the strategic decisions made by firms (RD (2) an increase in patent height may increase or decrease RD (3) while enforced patents will improve innovator profits they may worsen imitator profits, consumer welfare, or both and may even worsen total social welfare; (4) the optimal (social welfare maximizing) policy design is characterized by a relatively high patent height and moderate patent width.
Oxygen isotope evidence for shallow emplacement of Adirondack anorthosite

Oxygen isotopic analysis of wollastonites from the Willsboro Mine, Adirondack Mountains, New York reveals a 400-ft wide zone of 18O depletion at anorthosite contacts. Values of δ18O vary more sharply with distance and are lower (to −1.3) than any yet reported for a granulite fades terrain. Exchange with circulating hot meteoric water best explains these results and implies that the anorthosite was emplaced at relatively shallow depths, <10 km, in marked contrast to the depth of granulite fades metamorphism (23 km). These 18O depletions offer the first strong evidence for shallow emplacement of anorthosite within the Grenville Province and suggest that regional metamorphism was a later and tectonically distinct event.
Oxidative Transformation of Intermetallic Nanoparticles: An Alternative Pathway to Metal/Oxide Nanocomposites, Textured Ceramics, and Nanocrystalline Multimetal Oxides

A new low-temperature strategy is described for the synthesis of nanocrystalline multimetal oxides. In this approach, intermetallic nanoparticles synthesized via a modified polyol process are used as reactive precursors that help to define both the composition and morphology of multimetal oxides via a two-step thermal oxidation process. We use Bi2PdO4 and Bi2Pt2O7 as model systems for elaborating this new synthetic strategy. For Bi2PdO4, intermetallic Bi2Pd nanocubes are thermally oxidized to form a Bi2O3/Pd nanocomposite, which transforms to textured Bi2PdO4 upon further heating in O2. Bi2Pt2O7 is formed using a similar strategy involving the thermal oxidation of intermetallic Bi−Pt nanoparticles. The reaction pathway is established using a combination of X-ray diffraction analysis, transmission electron microscopy, thermogravimetric analysis, and energy-dispersive spectrometry element mapping data. Given the growing number of intermetallic compounds that are accessible as nanoparticles, this strategy ha...
Ductal spread in prostatic carcinoma

The histologic appearances of ductal invasion were studied in 139 cases of prostatic adenocarcinoma diagnosed in the Department of Pathology, Howard University Hospital, during the period January 1980 through October 1983. Intraductal spread was found in almost half (48%) of the prostatic glands examined. Ductal spread was associated with the local extent (P less than 0.001) rather than with the grade of the tumor (P less than 0.01). Three distinct patterns of ductal penetration were recognized. The duct wall was completely destroyed in microinvasion. In foci of ductal permeation the integrity of the basement membrane was generally preserved, and the duct wall was infiltrated mainly by solitary tumor cells. When the tumor spread was by extension in continuity within the duct wall, the neoplastic cells appeared to grow between the pre-existing epithelial layers. It was concluded that prostatic carcinoma cells have the ability to penetrate the wall of benign ducts and progressively replace the normal epithelial elements. In this process the general framework of the affected duct appears to be preserved.
Empirical Bayes and item-clustering effects in a latent variable hierarchical model: A case study from the National Assessment of Educational Progress

Empirical Bayes regression procedures are often used in educational and psychological testing as extensions to latent variables models. The National Assessment of Educational Progress (NAEP) is an important national survey using such procedures. The NAEP applies empirical Bayes methods to models from item response theory to calibrate student responses to questions of varying difficulty. Due partially to the limited computing technology that existed when NAEP was first conceived, NAEP analyses are carried out using a two-stage estimation procedure that ignores uncertainty about some model parameters. Furthermore, the item response theory model that NAEP uses ignores the effect of item clustering created by the design of a test form. Using Markov chain Monte Carlo, we simultaneously estimate all parameters of an expanded model that considers item clustering to investigate the impact of item clustering and ignoring uncertainty about model parameters on an important outcome measure that NAEP report. Ignoring ...
Prooxidant Activity of Polar Lipid Oxidation Products in Bulk Oil and Oil-in-Water Emulsion

Lipid oxidation products can arise when oils are subjected to high temperature and exposed to oxygen. Many of these oxidation products have higher polarity than the original triacylglycerols due to the incorporation of oxygen. These polar oxidation products could have a negative impact on oxidative stability by acting as prooxidants. In this study, the influence of polar lipid oxidation products on the oxidative stability of bulk oils and oil-in-water emulsions was investigated. Polar compounds were isolated from used frying oil by silica gel column chromatography. They were added to bulk stripped corn oil (with/without reverse micelles formed by dioleoylphosphatidylcholine, DOPC) and oil-in-water (O/W) emulsion to evaluate their prooxidative activity. Polar compounds increased lipid oxidation in bulk oil with and without DOPC. The presence of DOPC reverse micelles decreased the prooxidant activity of the polar oxidation products. On the other hand, there was no significant effect of the polar compounds on oxidation of O/W emulsions. To gain a better understanding of the polar compounds responsible for the prooxidant effect, linoleic acid and linoleic hydroperoxide were added into bulk oil at the same concentration as those in the polar fraction of the frying oil. However, they did not show the same prooxidative activity compared to oil with the polar fraction.
A medium-energy neutron facility☆

Abstract This paper describes a facility for producing variable energy neutron beams in the energy range 20 to 60 MeV using protons from the 76″ Isochronous Cyclotron at the University of California, Davis. The 7 Li(p, n) 7 Be reaction is used to produce nearly monoenergetic beams with approximately 60% of the neutrons in a well defined peak.
Conventional Surgical Treatment of Hepatocellular Carcinoma

Liver resection remains the standard therapy for solitary hepatocellular carcinoma in patients with preserved hepatic function. In well-selected patients, 5-year survival rates are good and can approach that of liver transplantation for early-stage disease. Patient selection is critical to optimizing therapeutic benefit, and the health of the native liver must be considered in addition to tumor characteristics. Hepatic recurrence after resection is common. The difficulty lies in deciding which patients with chronic liver disease and small solitary tumors are best served by resection and which should proceed with transplant evaluation; this is the focus of this article.
Haplotyping a quantitative trait with a high-density map in experimental crosses

Background The ultimate goal of genetic mapping of quantitative trait loci (QTL) is the positional cloning of genes involved in any agriculturally or medically important phenotype. However, only a small portion (≤ 1%) of the QTL detected have been characterized at the molecular level, despite the report of hundreds of thousands of QTL for different traits and populations. Methods/Results We develop a statistical model for detecting and characterizing the nucleotide structure and organization of haplotypes that underlie QTL responsible for a quantitative trait in an F2 pedigree. The discovery of such haplotypes by the new model will facilitate the molecular cloning of a QTL. Our model is founded on population genetic properties of genes that are segregating in a pedigree, constructed with the mixture-based maximum likelihood context and implemented with the EM algorithm. The closed forms have been derived to estimate the linkage and linkage disequilibria among different molecular markers, such as single nucleotide polymorphisms, and quantitative genetic effects of haplotypes constructed by non-alleles of these markers. Results from the analysis of a real example in mouse have validated the usefulness and utilization of the model proposed. Conclusion The model is flexible to be extended to model a complex network of genetic regulation that includes the interactions between different haplotypes and between haplotypes and environments.
FAD Mutations in Presenilin-1 or Amyloid Precursor Protein Decrease the Efficacy of a γ-Secretase Inhibitor: Evidence for Direct Involvement of PS1 in the γ-Secretase Cleavage Complex

To investigate the mechanism of regulation of Ass production by familial Alzheimer's disease (FAD)-linked presenilin 1 (PS1), we used a cell-free system that allows de novo Ass generation to examine whether PS1 participates directly in the gamma-secretase reaction. Optimal Ass generation in vitro was achieved at mildly acidic pH and could be inhibited by the aspartyl protease inhibitor pepstatin A, consistent with the suggestion that gamma-secretase is an aspartyl protease. Dominant negative mutations of the critical transmembrane aspartates in PS1 or full deletion of PS1 did not alter the maturation of APP in the secretory pathway. Instead, PS1 had a direct effect on the inhibition of Ass production by a designed peptidomimetic inhibitor: the inhibition was significantly less effective in cells expressing FAD-causing mutations in either APP or PS1 than in cells expressing the wild-type proteins. Taken together, these findings suggest that PS1 participates physically in a complex with APP during the gamma-secretase cleavage event.
The power of generosity to change views on social power

Abstract Intergroup helping behavior by high status group members typically functions to support and further entrench systems of social hierarchy (Nadler, 2002). This research examined whether the virtue of generosity could increase support for more egalitarian group relations, as indexed by reduced social dominance orientation (SDO; Pratto, Sidanius, Stallworth, & Malle, 1994). Pilot testing (N = 367) revealed a negative relationship between self-reported generosity and SDO. In Study 1, two long-term experimental manipulations of generosity in 110 college students reduced SDO. One manipulation involved a nine week community service learning project, and the other involved a five-part reflection paper assignment on generous individuals. In Study 2, a brief generosity prime in 58 college students reduced SDO scores. The potential benefits of targeting SDO directly, and the importance of examining the motives behind generosity are discussed.
Entropy, irreversible processes and fluctuations

Abstract The Gibbs and Boltzmann description of a system are contrasted for the entropy of a general Markov process. An H theorem is established for the Gibbs entropy. The master equation for non-stationary processes is introduced to initiate a discussion of the phenomenological equations in the two descriptions. The assumed connection between stationary state fluctuations and irreversible processes is exploited to yield the Nyquist relation for stationary processes.
Molecular weight effects and the sequential dynamic nature of poly(ethylene oxide) adsorption on silica from polydisperse aqueous solution

Adsorption kinetics of a polydisperse sample of poly(ethylene oxide) were studied using total internal reflectance fluorescence (TIRF), a method whose signal is approximately proportional to the adsorbed chain number. The initial stages of the adsorption process were found to be approximately transport-limited, dominated by single-chain adsorption for free solution concentrations below 100 ppm and clusters at higher concentrations. In the intermediate stages of single-chain adsorption, an overshoot occurs. The timing of the overshoot is extremely sensitive to the molecular weight distribution of the sample, and various populations of different molecular weights within the sample can be resolved. The signal decrease after the overshoot is attributed to one or both of the following processes : replacement of initially adsorbed short chains with ones of higher molecular weight, or interfacial reconfigurations driven by the filling of the surface and affecting the quantum yield of the fluorescent tag on the chain end.
Orthorhombic electron-paramagnetic-resonance spectrum of U 3+ in SrF 2

An EPR spectrum with orthorhombic symmetry of ${\mathrm{U}}^{3+}$ in ${\mathrm{SrF}}_{2}$ has been investigated. The principal axes and characteristic values of the $g$-tensor ellipsoid were determined. Twelve equivalent, yet distinguishable, spectra were resolved. The $12 X$ axes lie in {110} planes and are 15\ifmmode^\circ\else\textdegree\fi{} from 110g directions. The $Y$ axes lie in the same {110} planes 90\ifmmode^\circ\else\textdegree\fi{} from the corresponding $X$ axes (i.e., \ifmmode\pm\else\textpm\fi{} 15\ifmmode^\circ\else\textdegree\fi{} from 100g directions). The $12 Z$ axes were found to be in the 110g directions perpendicular to the {110} plane which contains the corresponding $X$ and $Y$ axes. These principal axes were determined to within \ifmmode\pm\else\textpm\fi{} 0.5\ifmmode^\circ\else\textdegree\fi{}. The principal $g$ values are ${g}_{x}=1.3276\ifmmode\pm\else\textpm\fi{}0.0005$, ${g}_{y}=2.88\ifmmode\pm\else\textpm\fi{}0.01$, and ${g}_{z}=3.183\ifmmode\pm\else\textpm\fi{}0.002$. A rotating sample holder which facilitated this investigation will be discussed briefly.
Properties of the Two States in Ca 40 near 9.87 MeV

The close-lying pair of resonances in the ${\mathrm{K}}^{39}(p, \ensuremath{\gamma}){\mathrm{Ca}}^{40}$ reaction, which correspond to excitation in ${\mathrm{Ca}}^{40}$ of about 9.87 MeV, have been measured to be at ${E}_{p}=1575.5\ifmmode\pm\else\textpm\fi{}0.8 \mathrm{and} 1580.0\ifmmode\pm\else\textpm\fi{}0.8$ keV by comparison with the ${\mathrm{Al}}^{27}(p, \ensuremath{\gamma}){\mathrm{Si}}^{28}$ resonance at 992 keV. Gamma-ray spectra obtained for both resonances show both have strong transitions to the ground state and to the first excited state. Weaker cascades through higher levels are also shown. The angular distribution of the ground-state radiation from the ${E}_{p}=1580$ keV level leads to an assignment of ${2}^{+}$ for the level. The radiation from this level to the 3.35 MeV (${0}^{+}$) first excited state appears enhanced, thus lending support to the suggestion by Pope et al. that the 3.35-MeV level may have a stable deformation and that upon this level is built a band of vibrational states at higher excitation. Resonant absorption measurements on the ground-state radiation from the ${E}_{p}=1575.5$-keV level gave ${\ensuremath{\Gamma}}_{t}=110\ifmmode\pm\else\textpm\fi{}30$ eV and ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}0}=1.36\ifmmode\pm\else\textpm\fi{}0.25$ eV. For the ${E}_{p}=1580$ keV level, the yield curve gave ${\ensuremath{\Gamma}}_{t}=1060\ifmmode\pm\else\textpm\fi{}200$ eV and a yield measurement gave ${\ensuremath{\Gamma}}_{\ensuremath{\gamma}0}=0.80\ifmmode\pm\else\textpm\fi{}0.26$ eV. At both levels, the ($p, \ensuremath{\alpha}$) cross section was measured to be \ensuremath{\le}68 \ensuremath{\mu}b and thus ${\ensuremath{\Gamma}}_{\ensuremath{\alpha}}l~0.012 \mathrm{and} 0.068$ eV for the lower and upper levels, respectively. The proton widths are thus 110\ifmmode\pm\else\textpm\fi{}30 and 1060\ifmmode\pm\else\textpm\fi{}200 eV. Arguments are given for $J=1$ assignment for the lower level. An even parity assignment is favored slightly by the experimental data. The possibility of "cross excitation" between the levels in the resonant absorption measurements is considered.
Conditions for optimum noise performance of transistor amplifiers with a reactive source

When driven from a purely reactive source, conventional noise figure is undefined for a two-port network such as an audio amplifier. In order to assess the noise performance of small-signal amplifiers driven from reactive sources such as capacitor microphones, a signal-to-wideband-average-noise ratio is defined. It is shown that for transducers where output is related to internal reactance by a simple transformer relationship and where the Thevenin equivalent internal impedance is a pure series R and L or C , there exists an optimum value of internal reactance for maximum signal-to-noise ratio when used with a given noisy amplifier. The equations for optimum reactance and signal-to-average-noise ratio are general and include low-frequency dependence of the transistor noise generators, equalization or frequency dependence of amplifier gain, and source resistance as well as reactance. Solutions are given for the practical audio case with typical low-noise audio transistors for both inductive and capacitive transducers.
Prediction of sudden cardiac death: next steps in pursuit of effective methodology.

The recognition that severe left ventricular dysfunction is a predictor of sudden cardiac death (SCD) risk enabled widespread utilization of the implantable cardioverter defibrillator (ICD) for SCD prevention. Use of the ICD prior to any signs or symptoms of ventricular arrhythmias (“primary prevention”) is particularly important for SCD because case fatality for patients with sustained ventricular tachyarrhythmias is among the highest of any disease process. At the same time, primary prevention of SCD presents a unique epidemiologic challenge for many reasons [1, 2]: (1) high-risk subgroups constitute only a small proportion of all patients at risk for SCD, (2) the pathophysiologic etiologies of SCD are complex and infrequently recognized prior to arrest, (3) ventricular arrhythmia substrate often evolves over time and may require repeated risk stratification, (4) classification of arrhythmic death is particularly imprecise, (5) triggers for SCD may be transient, and (6) patients at high risk for SCD have many competing risks that are not ameliorated by ICDs. This review will address the limitations of risk stratification based on left ventricular ejection fraction (LVEF), summarize new developments in the field that extend beyond LVEF, and suggest new investigative approaches for refinement of SCD risk assessment.
The Reagan Presidency, Growing Inequality, and the American Dream

For reasons that are not entirely clear, indices of inequality in the United States have increased since the 1970s. Evidence indicates that the policies of the Reagan administration were not the original cause of this inequality, but it does suggest that they contributed to that trend. This essay concludes that the political skills of the Reagan presidency, combined with the residual effects of the Democratic party's failure in the late 1970s, meant that Reagan was relatively immune to liberal attacks about growing inequality.
The “polarizing–tolerizing” mechanism of intestinal epithelium: its relevance to colonic homeostasis

Recent data indicate that stimulation of Toll-like receptors (TLRs) by intestinal microbiota supports colonic homeostasis. Intestinal epithelial cells (IECs) express several TLRs. It has been demonstrated that repeated exposure to TLR ligands causes IECs to become hypo-responsive. Inhibition of TLR cell surface expression and the induction of inhibitory intracellular signaling molecules have been proposed to mediate this state of tolerance to luminal commensals and/or their TLR ligands. In this review, we summarize our recent observations that uncover the essential role of IEC polarization in the homeostatic response of IECs to TLR ligands. In particular, apical TLR9 stimulation delivers negative signals that curtail inflammatory responses induced by basolateral stimulation by other TLRs. This "polarizing-tolerizing" ability of IECs represents a unique mechanism that restrains inflammatory responses in a bacteria-rich environment. Thus, interventions that enhance IEC polarization could prevent or inhibit human inflammatory bowel diseases and other types of intestinal inflammation.
Perceived Competencies of Elementary and Special Education Teachers

AbstractThe purpose of this study, conducted with 180 elementary and special education teacher graduates of Bowling Green State University, was to identify competency areas needed in teaching and to analyze teachers’ reported proficiency in these competencies. The elementary teachers’ most needed competencies were in the areas of student motivation, utilization of audiovisual equipment, and maintaining order in the classroom. The special education teachers ranked maintaining order in the classroom, student motivation, and developing social skills as their most needed competencies. A moderately high relationship (p = .58 and .73, respectively) was found between elementary and special education teachers’ reported need for a competency and their perceived proficiency within the competency area. The results were interpreted in terms of the existing literature and implications for teacher training.
Microbial endocrinology as a basis for improved l-DOPA bioavailability in Parkinson’s patients treated for Helicobacter pylori

Antibiotic therapy to eradicate Helicobacter pylori, the causative agent of gastric and duodenal ulcers, has been suggested to improve L-DOPA bioavailability in Parkinson's and thereby improve patient symptomology. To date, there has been no proven mechanism to explain the purported benefit of treatment of H. pylori in the management of Parkinson's disease. I propose the hypothesis, and provide initial data, that the mechanism of action is due to direct utilization of L-DOPA by H. pylori to maintain its ecological niche within the gastrointestinal tract. In support of this hypothesis, data is presented which demonstrates for the first time the ability of L-DOPA to influence the in vitro growth of H. pylori in an iron-restricted minimal medium. H. pylori utilization of L-DOPA for its own growth requirement reduces the amount of per orally administered L-DOPA that would be available to the patient for the treatment of Parkinson's disease-related pathology. Neuroendocrine-mediated interactions with bacteria represent the emerging interdisciplinary field of microbial endocrinology. Thus, microbial endocrinology provides for a mechanism between L-DOPA and H. pylori with which to explain the purported benefit of H. pylori-directed antibiotic therapy to improve L-DOPA bioavailability in Parkinson's patients and thereby improve drug therapy management. Further, if other bacterial species within the gastrointestinal tract depend on the availability of L-DOPA or other similar neuroendocrine-based drugs for their survival, then the efficacy of such neuroendocrine-based drugs not restricted solely for the management of parkinsonian symptomology may also be adversely affected and may therefore justify the use of an antibiotic regimen to eradicate them.
Regularity estimates for solutions of the equations of linear elasticity in convex plane polygonal domains

The Dirichlet problem for the plane elasticity problem on a convex polygonal domain is considered and it is proved that for data in L 2 the H 2 regularity estimate holds with constants independent of the Lame coefficients.
Impact of aerobic exercise on neurobehavioral outcomes

Numerous studies have examined the relationship between physical activity and cognitive function, demonstrating that greater physical activity is associated with lower incidence of cognitive impairment in later life. Due to an increasingly large number of older adults at risk for cognitive impairment, the relationship between physical activity and cognition has garnered increasing public health relevance and multiple randomized trials have demonstrated that exercise interventions among sedentary adults improve cognitive performance in multiple domains of function. This article will examine the relationship between physical activity and cognitive function by reviewing several different areas of literature, including the prevalence of cognitive impairment, assessment methods, observational studies examining physical activity and cognition, and intervention studies. The present review is intended to provide a historical tutorial of existing literature linking physical activity, exercise, and cognitive function among both healthy and clinical populations.
Using the absorbed power method to evaluate effectiveness of vibration absorption of selected seat cushions during manual wheelchair propulsion

Although wheelchair users are frequently subjected to oscillatory and shock vibrations, little research has been conducted to assess the whole-body vibration exposure of wheelchair users. The purpose of this study was to determine if selected wheelchair cushions alter potentially harmful whole-body vibrations transferred to wheelchair users. Thirty-two participants, who use wheelchairs as their primary mode of mobility, contributed to this study. Four of the most commonly prescribed wheelchair cushions were selected. Participants were asked to propel their wheelchair over a simulated activities of daily living (ADL) course while acceleration and force data were recorded. A repeated measures ANOVA showed no significant differences between the different cushions for the total averaged absorbed power (p = 0.190), the 50 mm curb drop (p = 0.234), or the rumble strip (p = 0.143). A repeated measure ANOVA for the peak curb drop absorbed power revealed a significant difference in the cushions (p = 0.043). The cushions that were most effective in this testing appear to be the Invacare Pindot and the Varilite Solo. Not only did those cushions appear to have the lowest values much of the time but also they did not display the highest values. When comparing results from a similar study, absorbed power appears to be as effective in determining vibration effects in the time domain as the methods in the ISO 2631 Standard.
Crystal structure and low-temperature emission of [(dmp)Cu(μ-S2butphos)2Cu(dmp)][BF4]2·6CH2Cl2 (dmp=2,9-dimethyl-1,10-phenanthroline; S2butphos=1,4-bis(diphenylphosphinesulfido)butane)

The synthesis and crystal structure of a bimetallic luminescent Cu(I) complex containing 1,4-bis(diphenylphosphinesulfido)butane and the α-diimine 2,9-dimethyl-1,10-phenanthroline (dmp) is described. The coordination geometry about the Cu(I) center is pseudo-tetrahedral. Interplanar interactions between phenyl groups on the phosphine sulfide ligands and the phenanthroline exist which are indicative ofintramolecular π-stacking, leading to compressed S−Cu−S bond angles. The complex displays emission from a single metal-centered charge-transfer state at 77 K in a 4∶1 ethanol/methanol (v/v) glass. This is in contrast to the triphenylphosphine complex, which exhibits dual luminescence from a charge-transfer and an intraligand state at 77 K. Crystal data: triclinic, $$P\bar 1$$ ,a=13.619(4) A,b=13.673(2) A,c=15.384(2) A, α=75.08(1)°, β=80.35(2)°, γ=80.67(2)°.
Altered bile acid metabolism in primary biliary cirrhosis

Selected aspects of bile acid metabolism were assessed in six women with primary biliary cirrhosis and varying degrees of cholestasis. Urinary bile acid excretion was markedly increased and correlated highly with serum levels. In three patients in whom urinary bile acids were separated by chromatography, the majority of urinary bile acids were monosulfated (34%, 42%, 32%) or polysulfated and/or glucuronidated (30%, 20%, 38%). The monosulfates of chenodeoxycholic acid were conjugated at either the 3 position (67%, 68%, 73%) or the 7 position (33%, 32%, 27%); similarly, the monosulfates of cholic acid were conjugated at the 3 position (65%, 58%, 68%) or the 7 position (35%, 42%, 32%). The position of sulfation was not markedly influenced by the mode of amidation with glycine or taurine. Chenodeoxycholic exchangeable pool size, turnover rate, and synthesis were measured by isotope dilution and found to be well within normal limits, despite the cholestasis. The fraction of chenodeoxycholic acid synthesis excreted in urine ranged from 9 to 48%; 4–38% of chenodeoxycholic acid synthesis was sulfated. These data indicate that the major abnormalities in bile acid metabolism in patients with cholestasis secondary to primary biliary cirrhosis are formation of sulfated bile acids in greatly increased amounts, elevation of blood levels of primary bile acids, and a shift to renal excretion as a major mechanism for bile acid elimination. Chenodeoxycholic acid synthesis continues at its usual rate despite cholestasis. Whether these changes, including the formation of 7-monosulfated bile acids, occur in other forms of cholestasis and whether either the persistance of unchanged chenodeoxycholic acid synthesis or the formation of such novel conjugates has any pathophysiological significance remain to be investigated.
Studies on the fine structure of Lophomonas blattarum with special reference to the so-called parabasal apparatus

Extending down the central axis of Lophomonas blattarum is a trumpet-shaped body, the calyx. Arranged in rows and attached to the anterior end of the calyx is a tuft of flagella. Each flagellum possesses the usual 11 filaments and ends in a typical basal body. The calyx membrane in the region of the basal bodies appears continuous, thick and fibrous. Below this region it is composed of a series of discrete longitudinally and obliquely arranged plates; these gather below the nucleus to form a bundle which extends posteriorly as the axial filament. Surrounding the calyx in the region of the nucleus is a specialized collar of cytoplasm known as the “parabasal apparatus.” The electron microscope reveals this region to possess numerous radiating tubules which penetrate the calyx and apparently join directly with the nucleus. Each tubule consists of (1) a distal, or body portion (about 2.5 μ long and 280 m μ wide) which narrows abruptly to (2) a highly convoluted, tortuous, and possibly conducting portion (about 62 m μ in diameter) which in turn penetrates the calyx membrane by passing through or between the plates, (3) a calyx portion which is highly twisted and shows some anastomosis of tubules, and (4) a constricted junctional portion (about 40 m μ in diameter) which appears to perforate the nuclear envelope. The calyx, perinuclear tubules and nucleus may rotate together within the organism.
Different Cellular and Genetic Basis of Noise-Related Endocochlear Potential Reduction in CBA/J and BALB/cJ Mice

The acute and permanent effects of noise exposure on the endocochlear potential (EP) and cochlear lateral wall were evaluated in BALB/cJ (BALB) inbred mice, and compared with CBA/J (CBA) and C57BL/6 (B6) mice. Two-hour exposure to broadband noise (4-45 kHz) at 110 dB SPL leads to a approximately 50 mV reduction in the EP in BALB and CBA, but not B6. EP reduction in BALB and CBA is reliably associated with characteristic acute cellular pathology in stria vascularis and spiral ligament. By 8 weeks after exposure, the EP in CBA mice has returned to normal. In BALBs, however, the EP remains depressed by an average approximately 10 mV, so that permanent EP reduction contributes to permanent threshold shifts in these mice. We recently showed that the CBA noise phenotype in part reflects the influence of a large effect quantitative trait locus on Chr. 18, termed Nirep (Ohlemiller et al., Hear Res 260:47-53, 2010b). While CBA "EP susceptibility" alleles are dominant to those in B6, examination of (B6 × BALB) F1 hybrid mice and (F1 × BALB) N2 backcross mice revealed that noise-related EP reduction and associated cell pathology in BALBs are inherited in an autosomal recessive manner, and are dependent on multiple genes. Moreover, while N2 mice formed from B6 and CBA retain strong correspondence between acute EP reduction, ligament pathology, and strial pathology, N2s formed from B6 and BALB include subsets that dissociate pathology of ligament and stria. We conclude that the genes and cascades that govern the very similar EP susceptibility phenotypes in BALB and CBA mice need not be the same. BALBs appear to carry alleles that promote more pronounced long term effects of noise on the lateral wall. Separate loci in BALBs may preferentially impact stria versus ligament.
Hydrography and circulation of the West Antarctic Peninsula Continental Shelf

The water mass structure and circulation of the continental shelf waters west of the Antarctic Peninsula are described from hydrographic observations made in March—May 1993. The observations cover an area that extends 900 km alongshore and 200 km o⁄shore and represent the most extensive hydrographic data set currently available for this region. Waters above 100—150 m are composed of Antarctic Surface Water and its end member Winter Water. Below the permanent pycnocline is a modified version of Circumpolar Deep Water, which is a cooled and freshened version of Upper Circumpolar Deep Water. The distinctive signature of cold and salty water from the Bransfield Strait is found at some inshore locations, but there is little indication of significant exchange between Bransfield Strait and the west Antarctic Peninsula shelf. Dynamic topography at 200 m relative to 400 m indicates that the baroclinic circulation on the shelf is composed of a large, weak, cyclonic gyre, with sub-gyres at the northeastern and southwestern ends of the shelf. The total transport of the shelf gyre is 0.15 Sv, with geostrophic currents of order 0.01 m s~1. A simple model that balances across-shelf di⁄usion of heat and salt from o⁄shore Upper Circumpolar Deep Water with vertical di⁄usion of heat and salt across the permanent pycnocline into Winter Water is used to explain the formation of the modified Circumpolar Deep Water that is found on the shelf. Model results show that the observed thermohaline distributions across the shelf can be maintained with a coeƒcient of vertical di⁄usion of 10~4 m2 s~1 and horizontal di⁄usion coeƒcients for heat and salt of 200 and 1200 m2 s~1, respectively. When the e⁄ects of double di⁄usion are included in the model, the required horizontal di⁄usion coeƒcients for heat and salt are 200 and 400 m2 s~1, respectively. ( 1999 Elsevier Science Ltd. All rights reserved.
BCG-induced protection against malignant melanoma: possible immunospecific effect in a murine system.

This report documents for the first time BCG-induced protection against a murine malignant melanoma. Adult Balb/C mice recieved 0.1-cm3 doses of BCG prior to intramuscular challenge with 1 x 10-6 S-91 melanoma cells. A 65% reduction in melanoma incidence was noted in BCG-pretreated mice. The possibility of specific protection induced by the BCG against the melanoma exists, since the BCG pretreatment did not protect against challenge with 1 x 10-5 mammary carcinoma cells or 1 x 10-4 MCA fibrosarcoma cells in the same strain of mice. Lack of immunogenicity was not a factor in the inability of the carcinoma and sarcoma to be inhibited by BCG. The strenght of the BCG-induced protection against the S-91 melanoma was demonstrated by significantly decreased tumor incidence following three different log challenge doses of the melanoma. However, reduction of the sarcoma challenge dose to as few as 10-2 cells administered to BCG pretreated mice did not result in decreased tumor incidence. It was further discovered that as few as two doses of 0.1 cm3 of BCG were sufficient to produce a 70% reduction in melanoma incidence compared with the incidence in control animals (P less than .001). Lymphocyte-mediated cytotoxicity studies paralleled the results of the in vivo experiments. Lymphocytes immune to each of the three tumors showed significant cytotoxicity against their respective tumor target cells (p less than .001), while the only tumor cells that lymphocytes from BCG-pretreated mice showed significant cytotoxicity against were S-91 target cells (p less than .01). Nonspecific cytotoxicity was not a factor in the effect of BCG-immune lymphocytes against S-91 target cells, since BCG-immune lymphocytes were not cytotoxic to Balb/C fibroblasts.
A precision low-flow-rate air delivery system for use with olfactometers

A precision air delivery system was adapted for use with insect olfactometers where a regulated low flow rate is desirable. The system employs hypobaric flow regulated by a barostat tower and a series of capillary flowmeters. Air flow is regulated by a balance of pressures on either side of the capillary. The regulated air flow is fed through Teflon lines to the olfactometer chambers. Flow-rate adjustments ranging from 5 ml to 5 liter/min can be made by changing the pressure on the system through the barostat tower or by changing the size of the capillary.
High performance question/answering

In this paper we present the features of a Question/Answering (Q/A) system that had unparalleled performance in the TREC-9 evaluations. We explain the accuracy of our system through the unique characteristics of its architecture: (1) usage of a wide-coverage answer type taxonomy; (2) repeated passage retrieval; (3) lexico-semantic feedback loops; (4) extraction of the answers based on machine learning techniques; and (5) answer caching. Experimental results show the effects of each feature on the overall performance of the Q/A system and lead to general conclusions about Q/A from large text collections.
Measuring Success in the Treatment of Children in the Emergency Department Setting: Process Versus Outcomes?

The current best design practices for clinical studies require consideration of the assessment of end points that combine key processes and outcomes. Process assessment measures events in the pathway on which a more important intermediate or ultimate health outcome depends. Process assessment can be either formative or summative. Outcomes assessment relates to identifying the results related to a process, and is most often defined as the change in a patient's current or future health state. The development of process and outcomes measures for any study is difficult, and children and emergency department settings present unique sets of issues worth highlighting. This article presents an overview of issues relating to choice of process and outcomes measures in studies of pediatric emergency medicine. Asthma care is used to illustrate the complex issues surrounding the measurement of success in management in the emergency department setting.