cssi/SciSciGPT-SciSciNet huggingface dataset:
CAD in CT colonography without and with oral contrast agents: Progress and challenges

Abstract Computed tomographic colonography (CTC), also known as virtual colonoscopy, is an emerging alternative technique for screening of colon cancers. CTC uses CT to provide a series of cross-sectional images of the colon for detection of polyps and masses. Fecal tagging is a means of labeling of residual feces by an oral contrast agent for improving the accuracy in the detection of polyps. Computer-aided diagnosis (CAD) for CTC automatically determines the locations of suspicious polyps and masses in CTC and presents them to radiologists, typically as a second opinion. Despite its relatively short history, CAD has become one of the mainstream techniques that could make CTC prime time for screening of colorectal cancer. Rapid technical developments have advanced CAD substantially during the last several years, and a fundamental scheme for the detection of polyps has been established, in which sophisticated 3D image processing, analysis, and display techniques play a pivotal role. The latest CAD systems indicate a clinically acceptable high sensitivity and a low false-positive rate, and observer studies have demonstrated the benefits of these systems in improving radiologists’ detection performance. Some technical and clinical challenges, however, remain unresolved before CAD can become a truly useful tool for clinical practice. Also, new challenges are facing CAD as the methods for bowel preparation and image acquisition, such as tagging of fecal residue with oral contrast agents, and interpretation of CTC images evolve. This article reviews the current status and future challenges in CAD for CTC without and with fecal tagging.
3-OST-7 Regulates BMP-Dependent Cardiac Contraction

The 3-O-sulfotransferase (3-OST) family catalyzes rare modifications of glycosaminoglycan chains on heparan sulfate proteoglycans, yet their biological functions are largely unknown. Knockdown of 3-OST-7 in zebrafish uncouples cardiac ventricular contraction from normal calcium cycling and electrophysiology by reducing tropomyosin4 (tpm4) expression. Normal 3-OST-7 activity prevents the expansion of BMP signaling into ventricular myocytes, and ectopic activation of BMP mimics the ventricular noncontraction phenotype seen in 3-OST-7 depleted embryos. In 3-OST-7 morphants, ventricular contraction can be rescued by overexpression of tropomyosin tpm4 but not by troponin tnnt2, indicating that tpm4 serves as a lynchpin for ventricular sarcomere organization downstream of 3-OST-7. Contraction can be rescued by expression of 3-OST-7 in endocardium, or by genetic loss of bmp4. Strikingly, BMP misregulation seen in 3-OST-7 morphants also occurs in multiple cardiac noncontraction models, including potassium voltage-gated channel gene, kcnh2, affected in Romano-Ward syndrome and long-QT syndrome, and cardiac troponin T gene, tnnt2, affected in human cardiomyopathies. Together these results reveal 3-OST-7 as a key component of a novel pathway that constrains BMP signaling from ventricular myocytes, coordinates sarcomere assembly, and promotes cardiac contractile function.
Phase and Texture Evolution in Chemically Derived PZT Thin Films on Pt Substrates

The crystallization of lead zirconate titanate (PZT) thin films was evaluated on two different platinum-coated Si substrates. One substrate consisted of a Pt coating on a Ti adhesion layer, whereas the other consisted of a Pt coating on a TiO2 adhesion layer. The Pt deposited on TiO2 exhibited a higher degree of preferred orientation than the Pt deposited on Ti (as measured by the Full Width at Half Maximum of the 111 peak about the sample normal). PZT thin films with a nominal Zr/Ti ratio of 52/48 were deposited on the substrates using the inverted mixing order (IMO) route. Phase and texture evolution of the thin films were monitored during crystallization using in situ X-ray diffraction at a synchrotron source. The intensity of the Pt3Pb phase indicated that deposition on a highly oriented Pt/TiO2 substrate resulted in less diffusion of Pb into the substrate relative to films deposited on Pt/Ti. There was also no evidence of the pyrochlore phase influencing texture evolution. The results suggest that PZT nucleates directly on Pt, which explains the observation of a more highly oriented 111 texture of PZT on the Pt/TiO2 substrate than on the Pt/Ti substrate.
Stress Myocardial Perfusion Imaging for Assessing Prognosis: An Update

A strength of nuclear myocardial perfusion imaging (MPI) is the wealth of prognostic data accumulated over 30 years of experience with this technique. Nuclear MPI can predict outcomes and guide revascularization decisions in symptomatic patients and is well validated in special populations such as patients with diabetes and chronic renal disease. Known limitations, such as underestimation of ischemia and radiation burden, are being progressively reduced through advances such as positron emission tomography absolute flow quantification and fusion with computed tomography, new camera hardware and software, and stress-only protocols. Advanced statistical techniques and increasing focus on comparative effectiveness and appropriateness will continue to optimize nuclear cardiology going forward.
The phases formed by heating Mn(II) and Zn(II) exchanged α-zirconium phosphate

Abstract The phases formed upon heating α-zirconium phosphate, Zr(HPO4)2·H2O, loaded to different levels of Mn(II) and Zn(II) were determined by a combination of thermal and X-ray powder methods. The fully exchanged phases, ZrM(PO4)2·4H2O lose water stepwise at progressively higher temperatures until anhydrous. Above 500°C the X-ray pattern indicates a triphosphate-like phase of the type M0.5Zr2(PO4)3 is formed. At lower loadings, solid solutions with relatively broad composition regions are observed. The data are summarized in phase diagrams which, however, are not equilibrium diagrams.
Lipid metabolism in myocardial cell-free homogenates.

Abstract A rat heart homogenate system was employed to investigate the effect of oxygen deficiency on carbohydrate and lipid metabolism. Anserobiosis altered the metabolism of [1-14C]palmitate from that of oxidation to enhanced esterification into phospholipid and neutral lipid fractions. Peak incorporation of radioactivity into phospholipid preceded peak incorporation into both diglyceride and triglyceride which suggests formation of a phospholipid precursor in synthesis of glycerides. In anaerobic homogenates from glycogen-depleted hearts incubated with ATP, recovery of [1-14C]palmitate in the phospholipid, diglyceride and triglyceride fractions was markedly depressed in the absence of glucose. Addition of either glucose or α-glycerophosphate stimulated incorporation of [1-14C]palmitate into these fractions to levels significantly greater than those observed in the aerobic system. The ability of α-glycerophosphate to enhance the formation of these lipids suggests a role for this metabolite as an essential intermediate in the synthesis of phospholipid and neutral lipid by the anoxic myocardium. Transesterification reactions play only a minor role in the observed increases in phospholipid, diglyceride and triglyceride activity seen in the anaerobic homogenate.
Automated invariant maintenance via OCL compilation

UML design models, specifically their declarative OCL invariants, must be refined into delivered code. A key problem is the need to integrate this logic with programmer-written code in a non-intrusive way. We recently developed an approach, called mode components, for compiling OCL constraints into modules that implement logic for transparently maintaining these constraints at run time. Specifically, mode components are implemented as nested C++ class template instantiations. The approach makes use of a key device-status variables. The attributes of a component to which other components are sensitive are called its status. A status variable is a lightweight wrapper on a status attribute that detects changes to its value and transparently invokes a method to handle announcements to dependent components. A mode component is a wrapped code unit containing one or more status variables. The contribution of this paper is a technique for achieving this integration using metaprogramming techniques.
Excited spectator electron effects on spectral line shapes

Excited spectator electron effects on Stark broadened spectral line shapes of transitions involving tightly bound electrons are investigated. It is shown that the interference terms in the electron impact broadening are essential to describe the overlapping lines generated by these configurations (e.g.; dielectronic satellite lines). The main impact is narrower spectral features and reduced far wing intensities compared to calculations neglecting the interference terms.
Three-dimensional vector modeling and restoration of flat finite wave tank radiometric measurements

In this paper, a three-dimensional Fourier transform inversion method describing the interaction between water surface emitted radiation from a flat finite wave tank and antenna radiation characteristics is reported. The transform technique represents the scanning of the antenna mathematically as a correlation. Computation time is reduced by using the efficient and economical fast Fourier transform algorithm, To verify the inversion method, computations have been made and compared with known data and other avaliable results. The technique has been used to restore data of the finite wave tank system and other available antenna temperature measurements made at the Cape Cod Canal. The restored brightness temperatures serve as better representations of the emitted radiation than the measured antenna temperatures.
A rapid, direct microquantitative method for determination of cyclohexanone in physiological solutions and biological fluids and of the retention behavior of some volatile compounds by gas chromatography

Abstract A gas Chromatographic method for a rapid, direct microquantitative determination of cyclohexanone in physiological solutions and biological fluids is described. The retention behavior of some volatile organic compounds is also presented. The effect of column temperature on the retention behavior of cyclohexanone is briefly discussed. Other Chromatographic factors which might affect the analytical results are mentioned.
O-glycopeptides: a simple β-stereoselective glycosidation of serine and threonine via a favorable hydrogen bonding pattern.

Glycosidation of serine and threonine is promoted by using an intramolecular hydrogen bond to the hydroxyl group
Coping Skills for Children Undergoing Painful Medical Procedures

Children must undergo painful medical procedures in the treatment of many acute or chronic illnesses. Fear and anxiety surrounding these painful procedures may create significant stress for the child and family. This paper reviews current approaches used by health care professionals to help children cope with these medical procedures. In addition, considerations for using these strategies and suggestions for intervention are presented to help the pediatric nurse develop a plan of care for these patients.
A simple model for the crustacean cardiac pacemaker control system

Abstract The crustacean cardiac pacemaker is a particularly useful experimental preparation for the investigation of neural control of rhythmic phenomena. In this paper a review of the experimental literature concerned with the pacemaker system of the mantis shrimp Squilla is given. It is pointed out that the anatomy and physiology of this animal are such that a very simple model may serve to describe the significant characteristics of its cardiac pacemaker control system. Such a model, relating muscle tension and length to pacemaker membrane potential, is derived. The applicability and use of the model are discussed.
Further Studies on the Mode of Action of Organic Thionophosphate Insecticides

Recent studies by Diggle and Gage (1951) and by the authors (1952) have shown that highly purified parathion and certain other thionophosphate insecticides are poor inhibitors of the cholinesterase enzymes in vitro , and that the inhibitory actions widely described in the literature (DuBois, et al , 1949, Metcalf and March, 1949, Grob, et al ., 1950, Aldridge, 1950, and Giang and Hall, 1951) are probably due to traces of isomerides, such as O,S-diethyl O- p -nitrophenyl thiophosphate, which are formed very readily by heating during reaction or distillation, by ultraviolet radiation, or even by long standing at room temperature and in light. These isomerides are nearly as active in vitro inhibitors of cholinesterases as are the corresponding oxygen analogues of the thionophosphates, such as para-oxon (diethyl p -nitrophenyl phosphate) and are from 1000 to 10,000 or more times as active as the purified thionophosphates. Therefore the presence of the isomeride in the thionophosphate in traces as low as 0.01 per cent will produce appreciable cholinesterase inhibition at dilutions of the order of 10−6M such as have been generally credited to parathion.
Cytologic features and diagnostic pitfalls of primary ampullary tumors by endoscopic ultrasound-guided fine-needle aspiration biopsy.

BACKGROUND Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-guided FNAB) is highly sensitive and specific in cytologic diagnosis and clinical staging of malignant neoplasms of the gastrointestinal tract, pancreas, liver, and lymph nodes. However, no study has been performed to evaluate its accuracy, sensitivity, specificity, and the cytomorphologic features of suspected primary ampullary tumors. METHODS All EUS-guided FNABs of suspected primary ampullary lesions at the University of California Irvine Medical Center (Orange, CA) from January 1998 to September 2004 were retrospectively retrieved. The number of passes necessary to arrive at a preliminary diagnosis during adequacy assessment was documented. The cytologic features were analyzed with endosonographic correlation. Follow-up information was also collected. RESULTS Thirty-five patients were found, 17 men and 18 women. The mean age of the patients was 68.9 years (range, 34–87 yrs). Adenocarcinoma was diagnosed in 13 patients. Atypical cells were found in six patients, four of which were suspicious for adenocarcinoma and two of which were consistent with reactive atypia. Adenoma was diagnosed in two patients and carcinoid tumor in one. Thirteen patients had a diagnosis that was negative for malignant cells. The average number of aspiration passes was 2.4 (range, 1–6 passes). Follow-up information was available in 27 patients. There were three false-negative results and no false-positive results. The sensitivity, specificity, and the positive and the negative predictive values were 82.4%, 100%, 100%, and 76.9%, respectively. The diagnostic accuracy was 88.8%. The consistent cytologic features in specimens that were positive or suspicious for adenocarcinoma included high cellularity, single cells, 3-dimensional cell balls, high nuclear-to-cytoplasmic ratio, prominent nucleoli, coarse/uneven distribution of chromatin, and necrosis. CONCLUSIONS EUS-guided FNAB was accurate, sensitive, and specific in the assessment of suspected primary ampullary masses. Adenoma presented a diagnostic challenge and endosonographic correlation was instrumental to increase the diagnostic accuracy. Cancer (Cancer Cytopathol) 2005. © 2005 American Cancer Society.
Assessment of annihilation anxiety from projective tests

This report details procedures to measure annihilation anxiety, a concept derived from Freud's 1926 formulation of traumatic anxiety. A 25-item pencil-and-paper inventory administered to patient and to nonpatient samples is described, along with a brief summary of earlier findings. The delineation of nine interrelated experiential components of annihilation anxiety provides the background for the construction of Rorschach and TAT measures of the concept. Findings comparing the pencil-and-paper inventory and the projective test measures are presented as well as examples of responses judged to reflect annihilation anxiety from Rorschach and TAT protocols.
Reaction of Alizarin Red S with hydroxyapatite: Stoichiometry and surface effect

Abstract The interaction of Alizarin Red S (3,4-dihydroxy-9,10-dioxo-2-anthracenesulfonic acid, sodium salt) with hydroxyapatite was studied in aqueous solution. This interaction was designated in the literature as an adsorptive process, probably because it removed most of the dye from the aqueous solution below a certain concentration. It is, however, a reactive process since the analysis of phosphorus in the solution showed a linear rise with the amount of dye consumed, while the amount of calcium in the solution decreases. As the surface effects decrease, the ratio of the dye consumed to the phosphate ions released into the solution becomes constant, and equal to the Ca/P ratio in apatite. This supports the following stoichiometric equation Ca1O(OH)2(PO4)6 + 10AzHNa → 10CaAz↓ + 4HPO2−4 + 2H2PO−4 + 10Na− + 2H2O where AzHNa stands for Alizarin Red S. The calcium salt (CaAz·2H2O) was characterized by its elemental analysis and IR spectra.
Models of the Cytochromes. Axial Ligand Orientation and Complex Stability in Iron(II) Porphyrinates: The Case of the Noninteracting dπ Orbitals

The synthesis and characterization of seven bis-pyridine and bis-imidazole complexes of iron(II) tetramesitylporphyrinate are reported. X-ray crystal structures of three of the complexes, [Fe(TMP)(...
Excitation of giant resonance in 90Zr by inelastic 6Li scattering

Abstract Inelastic 6Li scattering by 90Zr was measured at 74 MeV. A broad structure, which appears to be the giant quadrupole resonance, was observed at 13.8 MeV excitation energy. This observation is in agreement with previous work done with ions lighter than 6Li.
Stress Intensity Factors for Anisotropic Fracture Test Specimens of Several Geometries

Stress intensity factors have been obtained for single-edge-notched, double-edge-notched, and double cantilever beam fracture toughness test specimens using a two-dimensional hybrid stress model fi...
Practical Sampling Techniques

Basic concepts of sampling. Part 1 Single-stage sampling: simple random sampling use of ancillary variables in simple random sampling systematic sampling varying probability sampling - sampling with probability proportional to size choice of sampling units - cluster sampling size of sample - cost and error self-weighting designs. Part 2 Stratified single-stage sampling: stratified sampling - introduction stratified simple random sampling stratified varying probability sampling size of sample and allocation to different strata self-weighting design in stratified single-stage sampling. Part 3 Multi-stage sampling: multi-stage sampling - introduction multi-stage simple random sampling multi-stage varying probability sampling size of sample and allocation to different stages self-weighting design in multi-stage sampling. Part 4 Stratified multi-stage sampling: stratified multi-stage sampling - introduction stratified multi-stage simple random sampling stratified multi-stage varying probability sampling size of sample and allocation to different strata and stages self-weighting designs in stratified multi-stage sampling. Part 5 Miscellaneous topics: miscellaneous sampling topics errors and biases in data and estimates planning, execution and analysis of surveys use of computers in survey sampling appendix 1 - list of notations and symbols appendix 2 - elements of probability and proofs of some theorems in sampling appendix 3 - statistical tables appendix 4 - hypothetical universe of 600 households in 30 towns in 3 states appendix 5 - case study - Indian national sample survey, 1964-5 appendix 6 - multi-country survey programmes.
Energy Infrastructure Damage Analysis for Hurricane Rita

In 2005, Hurricane Rita caused significant damage to the energy infrastructure in the Gulf of Mexico region. In the context of this investigation, the "energy infrastructure" refers to the offshore oil platforms, refineries, and gasoline supply stations in the region, often referred to as the "petroleum infrastructure," the natural gas supply lines, and the delivery of electric power. In this paper, we examine the structural damage to the networks as defined by restoration, resilience, and fragility with a focus on the analysis of the electric power delivery disruptions. Our concern is not on the evaluation of risk, but rather to provide those who assess hurricane risk with relevant structural damage prediction models. We provide correlations of hurricane wind speed data with outages. We conclude that high winds alone can create significant damage to the energy infrastructure system.
The Tall cell variant of papillary carcinoma of the thyroid : Cytologic features and loss of heterozygosity of metastatic and/or recurrent neoplasms and primary neoplasms

BACKGROUND The Tall cell variant of papillary carcinoma of the thyroid (TCV) is characterized by the proliferation of oxyphilic, tall, columnar cells with a height-to-width ratio of at least 2:1. TCV exhibits more aggressive clinical behavior than conventional thyroid papillary carcinoma (CPC). Cytologic features suggestive of TCV have been described in fine-needle aspiration material from primary tumors. Similarly, loss of heterozygosity (LOH) for chromosome 1 (D1S243) and the p53 gene (TP53) have been reported in TCV but not in CPC, thus making exploitation of this genetic feature a potential tool for molecular discrimination between these two neoplasms. METHODS Cytology samples of metastatic and/or recurrent neoplasms (M/R) (12 cases) and 7 cases of primary TCV obtained from 12 patients were evaluated. The cytologic findings of these cases were compared with previously published findings. Microdissection and polymerase chain reaction for LOH for chromosome 1 and p53 (D1S243 and TP53 markers) were performed on cytologic smears from 6 cases of M/R tumors and 3 cases of primary tumors. RESULTS More then 50% of M/R showed atypical follicular cells with enlarged nuclei, granular chromatin, nuclear grooves, pseudoinclusions, and abundant finely granular cytoplasm. Cells were disposed in monolayers (58%) and papillary clusters (50%). Similar findings were present in cases of primary TCV. LOH studies showed that 4 of 6 M/R were noninformative and 2 of 3 cases of primary TCV were informative for the D1S243 marker; however, in contrast with previously published reports, no LOH was detected for the markers evaluated. CONCLUSIONS M/R and primary TCV have similar cytologic features. Additional studies of larger series of M/R and primary TCV should be performed to delineate further any potential application of LOH for chromosome 1 and the p53 gene as a tool for diagnosing TCV with cytologic preparations. Cancer (Cancer Cytopathol) 1999;87:238–42. © 1999 American Cancer Society.
An engineering tool for fracture toughness testing

Abstract A chevron notch four-point bend geometry fracture specimen is presented which complements the chevron notched short rod and short bar geometry used in ASTM E1304, the newest standard for fracture toughness testing. Although the four-point bend samples require slightly more material, sample preparation is less involved. Therefore total testing costs are lower using this four-point bend geometry when testing materials with low to moderate toughness to yield strength ratios. To test the new four-point bend samples, a stand alone toughness tool has been developed which allows a fracture toughness measurement to be made in about 30 seconds. It is shown that the fracture toughness values, measured using this toughness tool, are identical to the values obtained when loading the samples in a servo hydraulic testing system using a four-point bend fixture in displacement control. The fracture toughness values obtained using either loading method agree with fracture toughness values obtained according to ASTM E399.
Tensile properties of ultradrawn polyethylene

Abstract : High density polyethylene filaments, prepared by a solid-state deformation in an Instron Capillary Rheometer, show unusually high crystal orientation, chain extension, axial modulus and ultimate tensile strength. The Young's modulus and ultimate tensile strength have been determined from stress-strain curves. Gripping of this high modulus polyethylene has been a problem heretofore. Nevertheless, the measurement of ultimate tensile strength has become feasible by a special gripping procedure reported in this study. Tensile moduli show an increase with sample preparation temperature and pressure. The effect of strain rate and frequency on modulus has also been evaluated by a combination of stress-strain data and dynamic tension plus sonic measurements over nine decades of time.
Grant making as advocacy: The emergence of social justice philanthropy

In recent decades the phrase “social justice philanthropy” has emerged to describe grant making for progressive social reform. This article investigates this new discourse based on a cross-sectional analysis of foundations that actively support nonprofit social action. Smaller foundations, younger foundations, and public foundations are more likely to mention social justice or social change in their program descriptions than are other philanthropic institutions. Results indicate that foundations that set international grant making and rights activities as priorities are more likely to adopt this sensitive discourse than are foundations dedicated to other subjects; foundations with longer legacies of supporting reform also discuss social justice more frequently. This article begins to clarify which foundations provide legitimacy for social change nonprofits through their discourse and offers new insights into the role of foundations as policy actors. These findings suggest that the main advocates for a liberal policy voice within the philanthropic community may be smaller foundations and those incorporated as public foundations, a radical flank that pressures other foundations to expand their funding repertoire.
The Practice of Interdependence in the Research and Development Sector: Fast Reactor Cooperation in Western Europe

Scholars of international politics have recently offered the concepts of transnationalism and interdependence as alternatives to the state-centric paradigm for studying the impact of advancing technology on modern world politics. 1 While these concepts in themselves are not new and may, to some extent, share the normative biases of earlier theoretical challenges to the state-centric model (e.g., regional integration theory), 2 they should be examined separately because of the undeniable increase of transnational economic and social activities in the present system.
PROSTATE SPECIFIC ANTIGEN AND PATHOLOGICAL FEATURES OF PROSTATE CANCER IN BLACK AND WHITE PATIENTS: A COMPARATIVE STUDY BASED ON RADICAL PROSTATECTOMY SPECIMENS

AbstractPurpose: We compared the relationship of pathological features and preoperative prostate specific antigen (PSA) levels of a consecutive series of black patients to a stage matched cohort of white patients treated during the same period.Materials and Methods: The radical prostatectomy specimens of 40 black patients were reviewed and tumor volume was determined. Histopathological features (stage, grade, zonal distribution of cancer foci), tumor volume and prostate weight were correlated to pretreatment serum PSA levels. These parameters were compared with those of 148 white patients matched by pathological stage.Results: Black patients exhibited a significantly higher incidence of seminal vesicle involvement (p = 0.03) and cancers with a Gleason score of 8 or more (p = 0.02), and a trend toward decreased pathologically organ confined, margin negative disease (40% black versus 53% white men, p = 0.13). Although the incidences of multifocal cancer were virtually identical (90 and 82%) in the 2 groups,...
Higher Rates of Clostridium difficile Infection among Smokers

Objectives Cigarette smoking has been shown to be related to inflammatory bowel disease. We investigated whether smoking affected the probability of developing Clostridium difficile infection (CDI). Methods We conducted a longitudinal study of 16,781 older individuals from the nationally representative Health and Retirement Study. Data were linked to files from the Centers for Medicare and Medicaid Services. Results Overall, the rate of CDI in older individuals was 220.6 per 100,000 person-years (95% CI 193.3, 248.0). Rates of CDI were 281.6/100,000 person-years in current smokers, 229.0/100,000 in former smokers and 189.1/100,000 person-years in never smokers. The odds of CDI were 33% greater in former smokers (95% CI: 8%, 65%) and 80% greater in current smokers (95% CI: 33%, 145%) when compared to never smokers. When the number of CDI-related visits was evaluated, current smokers had a 75% increased rate of CDI compared to never smokers (95% CI: 15%, 167%). Conclusions Smoking is associated with developing a Clostridium difficile infection. Current smokers have the highest risk, followed by former smokers, when compared to rates of infection in never smokers.
Ecobehavioural and biological studies on two species of seed infesting thrips (Thysanoptera: Insecta)

Ecobehavioural and biological aspects of two species of seed infesting thrips, vizChirothrips mexicanus Crawford andChiridothrips indicus Ramk. and Marg. are discussed with particular reference to their reproductive biology, population dynamics on different host plants and their damage potential to seed production of their primary host plants.
Network model for straining dominated particle entrapment in porous media

Abstract A network model has been developed to study and describe formation damage resulting from particle entrapment in porous media by straining or size exclusion. Unlike the previous network models, this model considers the simultaneous entry of a number of particles into the network, as well as the effects of fluid flow on the particle transport path. A systematic study has been carried out on the flow and entrapment of monodispersed particles as well as particles with a size distribution through different networks. The effects of various parameters such as network size, particle size distribution and pore size distribution on the extent of formation damage, manifested by permeability reduction have been discussed in this paper. The model has also been used to determine the degree of prefiltration required to prevent damage to injection wells during water flooding. The model predictions show good agreement with experimental data for several different runs. A single parameter is used to match the exact number of pore volumes required to produce damage to the porous media. This parameter was found to be constant for the two different sandstones studied and for different concentrations of particles in the suspension. The simulation was also performed using the “random walk model” (which does not account for the fluid flow effects on particle flow) for purposes of comparison. The permeability responses predicted by this random walk model show trends that are significantly different from those observed experimentally. The network model developed in this paper has wide application in water flooding and matrix acidizing operations where diverting agents are used.
Effects of paramyxoviral infection on airway epithelial cell Foxj1 expression, ciliogenesis, and mucociliary function.

To elucidate molecular mechanisms underlying the association between respiratory viral infection and predisposition to subsequent bacterial infection, we used in vivo and in vitro models and human samples to characterize respiratory virus-induced changes in airway epithelial cell morphology, gene expression, and mucociliary function. Mouse paramyxoviral bronchitis resulted in airway epithelial cell infection and a distinct pattern of epithelial cell morphology changes and altered expression of the differentiation markers β-tubulin-IV, Clara cell secretory protein, and Foxj1. Furthermore, changes in gene expression were recapitulated using an in vitro epithelial cell culture system and progressed independent of the host inflammatory response. Restoration of mature airway epithelium occurred in a pattern similar to epithelial cell differentiation and ciliogenesis in embryonic lung development characterized by sequential proliferation of undifferentiated cells, basal body production, Foxj1 expression, and β-tubulin-IV expression. The effects of virus-induced alterations in morphology and gene expression on epithelial cell function were illustrated by decreased airway mucociliary velocity and impaired bacterial clearance. Similar changes in epithelial cell Foxj1 expression were also observed in human paramyxoviral respiratory infection. Taken together, these model systems of paramyxoviral respiratory infection mimic human pathology and identify epithelial cell Foxj1 expression as an early marker of epithelial cell differentiation, recovery, and function.
A neural network approach to the 3-satisfiability problem

Abstract A circuit is described for which the interconnections may be established to reflect a particular instance of the 3-Satisfiability problem. Analysis of the circuit reveals that it can proceed from an unbiased starting state to a stable state which can be interpreted as a satisfying truth value assignment for the 3-Satisfiability problem, if such an assignment exists. This stable configuration represents the global minimum of an energy function. While no analytic evidence is presented to guarantee that the trajectory does not become trapped in a local minimum, supporting empirical evidence is cited which indicates that it does not. Finally, it is shown that the network scales polynomially with respect to the size of the 3-Satisfiability problem both in circuit hardware and in convergence time. The relevance of this phenomenon to the P = NP question is discussed.
Are all surgical referrals for endoscopic retrograde cholangiopancreatography necessary

Sir, Endoscopic retrograde cholangiopancreatography (ERCP) is the gold standard for the diagnosis of biliary obstruction.[1] The objective of this study was to evaluate the necessity of emergency ERCPs in the acute phase (first 72 h) regardless of the trend of the liver function tests, thus exposing acutely ill patients to the risks of an invasive procedure[2] in the post magnetic resonance cholangiopancreatography (MRCP) era.[3,4] There is no doubt that ERCP is a valuable and useful tool in management of hepatobiliary conditions. With less invasive diagnostic modalities, such as MRCP being available, the dogma of ERCP as a “gold standard” had to be re-evaluated. Between December 2003 and December 2006, 73 consecutive ERCPs requested by surgeons in our unit, in a district general hospital of the United Kingdom, were retrospectively analyzed. Indication and findings were then correlated with the trend in liver function tests: 73 patients (27 male and 46 female; median age, 57.95; and age range, 20–101 years) underwent ERCP during that three-year period. The indications at time of presentation were pancreatitis in 10 patients (13.7%, group I) and jaundice in 63 patients (86.3%, group II). Liver function test profile returned back to normal in 37 patients (50.7%, all from group II), improved in 10 patients (13.7%, three from group I, seven from group II), remained stagnant in 10 patients (13.7%, four from group I, six from group II), and deteriorated in 16 (21.9%, two from group I,14 from group II) before the emergency ERCP. ERCP findings did not reveal any stones in the first group; however, it demonstrated bile duct stones in all patients in the second group, requiring stone extraction and sphincterotomy. Our study shows that a percentage of our patients did indeed need ERCP; all of group II had calculi that required removal. It was however only 28% of patients (26 of 73) that had stagnant or deteriorating liver function tests, thus warranting an emergency ERCP in the acute setting (first 72 h), while the patients were acutely unwell. The outcome and conclusion of this study is that a supervised delay, with stringent monitoring of the trend of liver markers, will give many patients time to recuperate from their acute illness before an invasive procedure. This will also allow less invasive procedures, e.g., MRCP, play a role in selecting candidates for more invasive forms of management.
The Effect of Variability on the Optimal Size of a Feeding Territory

Synopsis. Previous empirical and theoretical work has focused on how feeding territory size is governed by average levels of food availability and intrusion pressure; the potentially important effects of variability have not yet been studied in detail. Here I incorporate variation in food availability and intrusion pressure in some simple optimality models of territory size. The results show that the possible effects of variability are diverse, including both increase and decrease in territory size. And in some cases, variation in food availability produces qualitatively different effects than variation in intrusion pressure.
Estrogenic Activity of 4-Mercuri-17β-estradiol and Its Mercaptide Following Systemic Administration

4-Mercuri-17β-estradiol (4ME) has been previously shown to have inherent and persistent estrogenic activity when applied directly into the uterine lumen of the rat. In this study, 4ME and its mercaptide with β-mercaptoethanol (4- [2-hydroxyethylmercapto] mercuri-17β-estradiol or 4MEM) were administered by intravenous injection to ovariectomized rats. Large doses (18.4 nmoles each day for 3 days) were estrogenic as evaluated by morphologic response. As evaluated by uterine glucose-6-phosphate dehydrogenase activity, 4MEM had a more persistent estrogenic effect than 4ME, while the latter equaled 17β-estradiol. When small doses (0.37 nmole) of 6,7- [3H]4ME and 6,7-[3H]4MEM were given, nonspecific binding prevented their delivery to uterus and pituitary. These experiments indicate that affinity-labeling mercury derivatives of 17β-estradiol are active estrogens following systemic administration of doses sufficient to overcome nonspecific binding. “Shielding” the reagent group of the steroid (Hg) with a small m...
Equivalence between reliable feedback communication and nonlinear filter stability

This paper further demonstrates an interplay between information theory and control theory, at the level of achievability of message-point communication schemes. We establish a relationship between reliable feedback communication and the stability of the nonlinear filter. With this, we show that a newly developed feedback communication encoder - the posterior matching scheme - achieves capacity if and only if it is reliable (i.e. any finite number of bits can be reliably decoded). By making this connection to hidden Markov models, we also provide sufficient conditions (e.g. ergodicity of the Markov process and non-degeneracy of the noisy channel) on when reliability occurs.
Diagnosis and management of thoracic and abdominal vascular injuries

Thoracic and abdominal vascular injuries present a formidable challenge to the most experienced surgeon. As prehospital care improves, more patients with these injuries are reaching the hospital alive. Thus, the trauma surgeon must be prepared to deal with them rapidly and precisely. Hemodynamically unstable patients should be transferred directly to the operating room. In stable patients with penetrating thoracic wounds, chest X-ray and arteriography are typically employed to exclude vascular injury. Patients sustaining blunt chest trauma can be screened effectively with CT scanning. Incisions are chosen based on the injured vessel. Hemorrhagic shock is the usual presentation for abdominal vascular trauma. A high index of suspicion is critical in diagnosing occult injuries. This presentation reviews the etiology, diagnosis, and treatment of major thoracic and abdominal vascular injuries.
Binocular rivalry and head-worn displays

OBJECTIVE: We provide a review and analysis of much of the published literature on binocular rivalry that is relevant to the design and use of head-worn displays (HWDs). BACKGROUND: This review draws heavily from both the basic vision literature and applied HWD literature in order to help provide insight for minimizing the effects of binocular rivalry when HWDs are worn. METHOD: Included in this review are articles and books found cited in other works as well as articles and books obtained from an Internet search. RESULTS: Issues discussed and summarized are (a) characteristics of binocular rivalry, (b) stimulus factors affecting rivalry, (c) cognitive variables affecting rivalry, and (d) tasks affected by rivalry. CONCLUSION: This paper offers a set of recommendations for minimizing the effects of binocular rivalry when HWDs are used as well as recommendations for future research. APPLICATION: Considerations of the basic vision literature on binocular rivalry will provide insight for future design solutions for HWDs. Language: en
Can the lee model be used in testing theories of pion-nucleus scattering?

Abstract The Lee model of π-nucleon interactions is very simple, and, in a certain case, an exact solution of the problem of a meson scattering on two “nucleons” can be obtained. However, graphs involving crossed pions are absent in that solution. Because such crossed graphs are crucial in determining the form and character of the physical π-nucleus scattering solution, the Lee model should not be used in testing field theories of the pion-nucleus interaction.
Revisiting film theory to consider approaches for enhanced solvent-process design for carbon capture

Application of carbon capture at the gigaton-scale necessary for significant reduction in atmospheric CO2 requires a portfolio of technologies for applications that may span point-source capture to more dilute systems such as CO2 removal from the atmosphere. We argue that for absorption separation processes there is a strong coupling between the solvent and process properties, which are uniquely dependent upon the starting concentration of CO2. We revisit Whitman's film theory and consider mass-transfer correlations to determine the most critical solvent and process parameters that influence the flux of CO2 from the gas to the liquid phase, within which it is ultimately captured. Finally, results of this work indicate, for instance, that increasing the kinetics of a reacting solvent with CO2 has a greater impact on direct air capture (DAC) systems, than natural gas- or coal-fired power plant emissions. In addition, the solvent kinetics is a more influential parameter than the Henry's law solubility coefficient for DAC systems, while the reverse may be found for more concentrated CO2 gas mixtures.
Control of loudspeakers using disturbance-observer-type velocity estimation

A new approach to obtain sensorless velocity feedback for loudspeakers is developed. The back electromotive force (back-EMF) of the moving coil is estimated by using a disturbance-observer-type estimator based on the coil current measurement. The cone velocity of a loudspeaker can be obtained based on its proportionality to the back-EMF. Instead of relying on the coupled mechanical dynamics as reported in previous work, the proposed velocity estimation is based on the precise knowledge of electrical impedance, which makes it more robust to changes in acoustic loading. The proposed approach enables the development of a robust velocity controller for a subwoofer without an expensive velocity measuring device. Experimental results demonstrated that closed-loop velocity control using the proposed scheme of velocity estimation achieved a performance comparable to that obtained by using measured velocity feedback. The proposed approach can be easily adapted to other moving-coil-type linear actuators.
Effects of Low Phytate Barley (Hordeum vulgare L.) on Zinc Utilization in Young Broiler Chicks

Two 21-d experiments were conducted to evaluate the effects of low phytate barley (LPB) on Zn utilization by young broiler chicks and to determine the contribution of endogenous phytase, present in LPB. In the first experiment, ninety-six 1-d-old male chicks were assigned to a 2 x 3 factorial arrangement of treatments (4 pens of 4 chicks/treatment). Factors were barley type [wild-type barley (WTB) and LPB mutant M 955] and supplemental Zn (0, 10, or 20 mg of Zn/kg). In the second experiment, two hundred forty 1-d-old straight-run broiler chicks were assigned to a 2 x 2 x 3 factorial arrangement of treatments (4 pens of 5 chicks/treatment). Factors were barley type (WTB and LPB), autoclave treatment [nonautoclaved or autoclaved (121 degrees C, 20 kg/cm(2), 20 min)], and supplemental Zn (0, 10 or 20 mg of Zn/kg). Barley made up 60% of the diets and was the only source of phytate. On average, basal diets contained 26 mg of Zn/kg. Feed intake and body weight gain were greater (P WTB) and supplemented Zn levels (20 > 10 > 0 mg of Zn/kg), and significant barley type x Zn interactions were also observed in both experiments. Substitution of LPB for WTB increased tibia and toe Zn by 46 and 25%, respectively, an increase comparable to that achieved with supplementing the diet with 20 mg of Zn/kg. No effect of autoclaving was observed for any variable in experiment 2. Retention of P and Zn was higher (P < 0.001) in chicks fed LPB compared with WTB in both experiments. Zinc retention was influenced (P < 0.0001) by dietary Zn, and barley type x Zn level interactions (P < 0.05) were observed in both experiments. Chicks fed LPB utilized more dietary Zn and P than those fed WTB, and this improved mineral utilization was not due to endogenous phytase present in barley.
Figure Embeddedness as a Function of the Orientation of Embedding-Field Contours

The ‘oblique effect’ was studied with the use of an embedded-figures task in which the percentage of contextual or embedding contours aligned in the same orientations as those comprising the hidden forms was systematically varied. For hidden forms comprised either of horizontal and vertical contours, or of oblique (45° and 135°) contours, search times increased markedly as the percentage of aligned contextual contours increased. Although the rate at which embeddedness increased was the same for both orientations, search times were consistently greater for locating obliquely oriented targets (p < 0–05), and search time variance was significantly greater (p < 0–025) on trials in which the hidden form was oblique. The results suggest that the laws of organization governing embeddedness apply equaly to oblique and horizontal—vertical orientations, but perceptual processing of oblique orientations is poorer. The relationship between search time and aligned contour is discussed in terms of the dual processes of...
Balancing fusion, image depth and distortion in stereoscopic head-tracked displays

Abstract Stereoscopic display is a fundamental part of virtual reality HMDsystems and HTD (head-tracked display) systems such as thevirtual workbench and the CAVE. A common practice instereoscopic systems is deliberate incorrect modeling of user eyeseparation. Underestimating eye separation is frequentlynecessary for the human visual system to fuse stereo image pairsinto single 3D images, while overestimating eye separationenhances image depth. Unfortunately, false eye separationmodeling also distorts the perceived 3D image in undesirableways. This paper makes three fundamental contributions tounderstanding and controlling this stereo distortion. (1) Weanalyze the distortion using a new analytic description. Thisanalysis shows that even with perfect head tracking, a user willperceive virtual objects to warp and shift as she moves her head.(2) We present a new technique for counteracting the shearingcomponent of the distortion. (3) We present improved methodsfor managing image fusion problems for distant objects and forenhancing the depth of flat scenes.CR Categories and Subject Descriptions: I.3.7 [ComputerGraphics] Three-Dimensional Graphics and Realism - VirtualReality; I.3.6 [Computer Graphics] Methodology and Techniques– Ergonomics; I.3.6 [Computer Graphics] Methodology andTechniques – Interaction Techniques; I.3.3 [Computer Graphics]Picture/Image Generation – Viewing AlgorithmsAdditional Keywords: virtual reality, stereoscopic display,head-tracking, image distortion