cssi/SciSciGPT-SciSciNet huggingface dataset:
Soil physiochemical changes following 12 years of annual burning in a humid–subtropical tallgrass prairie: a hypothesis

Abstract Burning is known to stimulate growth of grassland vegetation, promote species diversity, and inhibit natural invasion by woody plants. However, the frequency at which grasslands are burned as part of their management can affect soil nutrient content and, ultimately, productivity. The objective of this study was to characterize changes in soil physical and chemical properties in a native tallgrass prairie after 12 years of annual burning. In 1989, five soil samples from the 0 to 10 cm depth were collected along a transect through a 3 ha parcel of native tallgrass prairie in central Arkansas. Soil sampling was repeated in 2001 to assess changes over time. Results showed that soil bulk density, electrical conductivity, extractable P, Na, Fe, and Mn decreased significantly (P
An ion translocase system from rabbit intestinal mucosa. Preparation and properties of the (Na+-K+)-activated ATPase

1. 1. A particulate enzyme complex from rabbit intestinal mucosa exhibiting (Na+ + K+)-stimulated ATPase activity has been isolated and partially purified. 2. 2. The ATPase activity exhibits an asymmetric stimulatory response to Na+ and K+ and is inhibited by ouabain and Ca2+. 3. 3. Specific inhibition of the ATPase activity by mersalyl, phenolphthalein, and culture filtrates from Vibrio cholerae are also reported. 4. 4. It is concluded that the ATPase activity is a moiety of the membrane-associated ion translocase system of rabbit intestinal mucosa and that mucinase activity in the culture filtrates selectively destroys or inactivates this system in vitro.
Volumetric imaging with an amplitude-steered array

Volumetric acoustic imaging is desirable for the visualization of underwater objects and structures; however, the implementation of a volumetric imaging system is difficult due to the high channel count of a fully populated two-dimensional array. Recently, a linear amplitude-steered array with a reduced electronics requirement was presented, which is capable of collecting a two-dimensional set of data with a single transmit pulse. In this study, we demonstrate the use of the linear amplitude-steered array and associated image formation algorithms for collecting and displaying volumetric data; that is, proof of principle of the amplitude-steering concept and the associated image formation algorithms is demonstrated. Range and vertical position are obtained by taking advantage of the frequency separation of a vertical linear amplitude-steered array. The third dimension of data is obtained by rotating the array such that the mainlobe is mechanically steered in azimuth. Data are collected in a water tank at the Pennsylvania State University Applied Research Laboratory for two targets: a ladder and three pipes. These data are the first experimental data collected with an amplitude-steered array for the purposes of imaging. The array is 10 cm in diameter and is operated in the frequency range of 80 to 304 kHz. Although the array is small for high-resolution imaging at these frequencies, the rungs of the ladder are recognizable in the images. The three pipes are difficult to discern in two of the projection images; however, the pipes separated in range are clear in the image showing vertical position versus range. The imaging concept is demonstrated on measured data, and the simulations agree well with the experimental results.
Middleware architecture for evaluation and selection of 3rd party Web services for service providers

This paper presents an architecture to facilitate efficient evaluation and selection of 3rd party Web services for service providers. Most service provider architectures have primarily focused on providing Web service front ends to legacy systems, aggregating and delivering services via workflows. These architectures primarily considered static business contracts between the service provider and its (Web-service enabled) business partners. This approach makes these architectures inflexible to variations in business requirement, partners' performance and customer requirements. Our architecture provides a flexible means for service providers to optimize business performance. Based on the historical performance, extant context, and optimising business rules, the appropriate service is selected and invoked to serve a customer request. We have developed a prototype system ODSS-in-ENDS, that demonstrates this capability.
Abstract 3138: Development of a tetracycline-inducible lentiviral system for RNAi screen in PDX tumors.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Patient-derived xenograft (PDX) tumors are believed to be more clinically relevant pre-clinical models for cancer target identification and validation. We used a tetracycline-inducible lentiviral vector that delivers shRNA expression which is tightly linked to a GFP reporter in PDX cells. Using shRNAs against PLK1 (polo-like kinase 1) as positive controls, we demonstrated that three of the four PLK1 hairpins resulted in growth inhibition of HT29 and A549 cells upon dox induction. Correspondingly, these 3 hairpins showed significant knockdown of PLK1 mRNA. To facilitate RNAi in PDX tumors, we have established an in vitro system to culture PDX tumor cells. Gene expression and IHC study demonstrated that tumors regenerated from colon PDX cells grown in vitro retained features of their parental tumors. PDX cells cultured in vitro also remained tumorigenic. When GFP/shRNA-transduced colon PDX cells were re-implanted in mice to form tumors, approximately 30% of the new tumor cells was GFP-positive, enabling us to capture shRNA-expressing cells by flow cytometry. Initial shRNA drop-out screens were carried out in HT29 and colon PDX cells transduced with a pool of ∼600 shRNAs targeting a set of potential cancer associated genes. Included amongst the hairpins demonstrating statistically significant depletion in HT29 were the exact same three PLK1 shRNAs previously functionally validated. These results demonstrated that we have established a robust in vivo shRNA drop-out screening platform in PDX tumors for identification of novel cancer drug targets. Citation Format: Lei Chen, Yi Geng, Dave Fruhling, Wenyan Zhong, Veronica Diesl, Jing Pan, Christine Loreth, Elizabeth Wang, Yaroslava Bulynko, Kim Arndt, Maximillian Follettie. Development of a tetracycline-inducible lentiviral system for RNAi screen in PDX tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3138. doi:10.1158/1538-7445.AM2013-3138
Essential fatty acid deficiency: A new look at an old problem

Essential fatty acid (EFA) deficiency is a useful tool to study the role of arachidonate and its metabolites in various physiologic and pathologic states. Recent studies have clarified the effects of EFA deficiency on membrane arachidonate and its metabolites, and have demonstrated that 20:3(n-9) (which accumulates in EFA deficiency) can be metabolized to a variety of eicosanoids. EFA deficiency has been shown to exert an anti-inflammatory effect. The mechanism of this effect may in part be mediated through a decrease in leukocyte leukotriene formation. In contrast, studies using the novel fatty acid, columbinic acid, have shown that the epidermal dysfunction seen in EFA deficiency may be a function of linoleate and its lipoxygenase metabolites rather than of arachidonate and the prostaglandins. Finally, it has recently been shown that EFA deficiency potentiates the effects of volatile anesthetics. EFA deficiency may thus provide a useful tool to investigate the molecular mechanism of these drugs.
Determining average excitation energy

Abstract A procedure is presented for determining the initial excitation energy of an emitting source whose mass and charge is unknown. This procedure is based on the mean multiplicities of neutrons and H plus He isotopes, which are plotted against one another. It is suggested that the measurement of both the mean multiplicities for light and intermediate mass fragments might indicate the onset of multifragmentation.
Feedback regulation of Cyclooxygenase-2 transcription ex vivo and in vivo

Abstract Cyclooxygenase-2 (COX-2) is a rate-limiting enzyme for prostaglandin biosynthesis. Its inducible expression is regulated by complex pathways. To monitor Cox-2 transcriptional activity in vivo, we generated a knock-in mouse expressing a firefly luciferase reporter. In this study we examined, by comparing luciferase activity of Cox-2luc/+ and Cox-2luc/− cells and mice, effects of prostanoid products on Cox-2 promoter transcriptional activation. In peritoneal macrophages, luciferase induction by LPS in Cox-2luc/− cells was less than that of Cox-2luc/+ cells. However, in the presence of PGE2, induction was comparable, suggesting positive Cox-2 feedback regulation by PGE2 occurs for macrophages. In contrast, feedback modulation was not observed in TPA-induced Cox-2luc/+ and Cox-2luc/− mouse embryonic fibroblasts (MEFs). Using non-invasive in vivo imaging, we observed negative feedback regulation of Cox-2 expression during paw inflammation in living mice. Our results suggest Cox-2 expression is regulated by cell type specific feedback mechanisms, both in cultured cells and in living animals.
Determination of the intraparticle electroosmotic volumetric flow-rate, velocity and Peclet number in capillary electrochromatography from pore network theory.

Abstract The results obtained from the pore network model employed in this work, clearly show that the magnitudes of the intraparticle electroosmotic volumetric flow-rate, Qintrap, and velocity, 〈vintrap,x〉, in the pores of the charged porous silica particles considered in this study are greater than zero. The intraparticle Peclet number, Peintra, of a solute in these charged porous silica particles would be greater than zero, and, in fact, the magnitude of the intraparticle Peclet number, Peintrap, of lysozyme is greater than unity for all the values of the pore connectivity, nT, of the intraparticle pores and of the applied electric potential difference per unit length, Ex, along the axis of the capillary column considered in this work. Furthermore, the values of the intraparticle electroosmotic volumetric flow-rate, Qintrap, and velocity, 〈vintrap,x〉, as well as the magnitude of the pore diffusion coefficient, Dp, of the solute increase as the value of the pore connectivity, nT, of the intraparticle pores increases. The intraparticle electroosmotic flow can contribute significantly, if the appropriate chemistry is employed in the mobile liquid phase and in the charged porous particles, in (i) decreasing the intraparticle mass transfer resistance, (ii) decreasing the dispersive mass transfer effects, and (iii) increasing the intraparticle mass transfer rates so that high column efficiency and resolution can be obtained.
Nomogram based on metabolic equivalents and age for assessing aerobic exercise capacity in men

Objectives. The goal of this study was to create a nomogram, based on maximal exercise capacity (in metabolic equivalents [METs]) and age, for assessing a patient's ability to perform dynamic exercise to quantify the level of physical disability or relative capacity for physical activity. Background. Providing an estimation of exercise capacity relative to age is clinically useful. Such an estimate can be derived from measured or estimated maximal oxygen uptake (in METs) from treadmill exercise testing and age. It is an effective means of communicating to patients their cardiopulmonary states, encouraging improvement in exercise capacity and quantifying disability. Methods. Exercise test results of 1,388 male patients (mean age 57 years, range 21 to 89) free of apparent heart disease who were referred for exercise testing for clinical reasons were retrospectively reviewed. This referral group as well as subgroups of active (n = 346) and sedentary (n = 253) patients were analyzed to determine norms for age and for age by decades for exercise test responses, including METs, maximal heart rate and maximal systolic blood pressure. Regression equations were calculated from this information, and a nomogram for calculating degree of exercise capacity from age and MET level achieved by a patient was created. A similar analysis was performed in a separate group of 244 apparently healthy, normal male volunteers (mean age 45 ± 14 years, range 18 to 72) who underwent exercise testing with direct measurement of expired gases. Results. Equations for predicted METs for age were derived for the entire clinical referral group (METs = 18.0 − 0.15[Age]) and for the subgroups of active (METs = 18.7 − 0.15[Age]) and sedentary (METs = 16.6 − 0.16[Age]) patients. All results achieved statistical significance, with p values < 0.001. In the volunteer group of normal men who performed exercise testing with ventilatory gas exchange, the decline in maximal heart rate and METs with age was not as steep as in the referral group. Although the normal group confirmed nomograms published previously among similar subjects, the equations derieved from the patients differed from those previously reported; in contrast to previous studies using healthy volunteers, the equations and nomograms for the referral group are more appropriate for patients typically referred for testing in a hospital or office-based internal medicine practice. Conclusions. Norms for METs based on age are presented as well as population-specific nomograms that enable physicians to assess patients' exercise capacity relative to their age group.
Optical Pulse Distortion Measurement Limitations in Linear Time Invariant Systems, and Applications to Polarization Mode Dispersion

Abstract The optical pulse-distorting properties of a fiber network or device are sometimes deduced from spectral measurements or correlation measurements. In order to investigate the theoretical limitations on such deductions, single-mode optical networks are characterized in terms of linear, time-invariant filters. An optical impulse response is discussed which directly models pulse distortion in the time domain. This linear systems approach is then applied to measurements of polarization mode dispersion by Jones matrix eigenanalysis, low-coherence interferometry, and Fourier-transformed wavelength scanning (i.e. fixed analyzer) techniques. We show that, without restrictive assumptions of negligible chromatic dispersion, these techniques allow calculation of autocorrelations of output pulses, but not the output pulse shapes. We discuss the conditions under which chromatic dispersion may be neglected, and show that in this case the Jones matrix method allows calculation of the complete output pulse shape in response to an arbitrary input pulse.
Why Everyone Acts Altruistically All the Time: What Parodying Psychological Egoism Can Teach Us

Psychological Altruism (PA) is the view that everyone, ultimately, acts altruistically all the time. I defend PA by showing strong prima facie support, and show how a reinterpretive strategy against supposed counterexamples is successful. I go on to show how PA can be argued for in ways which exactly mirror the arguments for an opposing view, Psychological Egoism. This shows that the case for PA is at least as plausible as PE. Since the case for PA is not plausible, neither is that for PE.
Repeated Moral Hazard and One-Sided Commitment

Abstract This paper considers a repeated unobserved endowment economy with a restriction that agents can walk away from insurance contracts at the beginning of any period and contract with another insurer (one-sided commitment). An equilibrium is derived characterized by a unique, market-determined insurance contract with the property that agents never want to walk away from it. The paper shows that trade (or insurance) still occurs and that a non-degenerate long-run distribution of consumption exists. A numerical example shows that this distribution is nearly log-normal. Journal of Economic Literature Classification Numbers: D30, D31, D80, D82.
Consequences of overvalued equity: Evidence from earnings manipulation

Abstract Firms that made earnings-decreasing restatements over the period 1990 to 2001 lost $72 billion around restatement announcements. Forty-seven large-loss firms restating their earnings in the 1998 to 2001 period account for $66 billion of these losses. Despite very good stock performance and low book-to-market values before earnings misstatements, large-loss firms are associated with mean abnormal returns of − 39% during the announcement period, and underperform matched firms by 44% during the first post-restatement year. Collectively, our results support Jensen's [Jensen, M.C. Agency costs of overvalued equity. Financial Management 2005;34; 5–19.] argument that substantial overvaluation of equity pressures managers to manipulate earnings and when investors learn about earnings restatements by overvalued firms, they reevaluate firms to correct not only for pre-misstatement overvaluation, but also for the loss of confidence in the firms' managers.
Unanimity, Discord, and the Communication of Public Opinion

This article is concerned with the political communication of opinion that occurs through networks of associated citizens. Its primary attention focuses on opinion variance within populations and networks and how such variance affects communication among and between individuals. Particularly in the context of ambiguous or infrequent communication, people may experience difficulty in formingjudgments regarding the opinions of others. In such situations, environmental priors become useful devices for reaching these judgments, but a problem arises related to the utility of these environmental priors when discord rather than unanimity characterizes the contextual distribution of opinion. The article's argument is that dyadic discussions between two citizens are most enlightening, and environmental priors least enlightening, when surrounding opinion is marked by higher levels of disagreement. The analyses are based on data taken from the 1996 Indianapolis-St. Louis study.
In the Tower of Babel: Beyond symmetry in islamic design

A personal account of an interdisciplinary inquiry into the study of Islamic geometric design and architectural decoration touching on the fields of History, History of Science, Scientific Theory of Symmetry and History of Art. The study stresses the necessity of the use of a common scientific language of Symmetry Notation in order to discuss and communicate in a precise manner about Islamic geometric pattern. To understand Islamic geometric design, it is necessary to move beyond the symmetry issues, to the step-by-step process of design. This is based on primary sources of scientific manuscripts of practical geometry written specifically for the Muslim artisans. The research demonstrates not only a direct meeting but a collaborative work between science and art in Islamic civilization.
Fatal Diffuse Influenzal Pneumonia: Premortem Diagnosis by Lung Biopsy

Primary viral pneumonia is an uncommon but serious complication of influenzal infection. Pathologic changes in the lungs due to the virus per se are commonly obsecured by secondary bacterial infection. An extensive disseminated influenzal pneumonia in a 40-year-old woman was associated with intractable hypoxemia despite intensive supportive care, including continuous positive pressure breathing, hypothermia and adrenal corticosteroids. Open lung biopsy early in the course of the disease showed pathologic changes attributable to “pure” virus pneumonia free from bacterial superinfection at that time. Death eventually occurred from secondary bacterial and fungal pneumonia demonstrated at autopsy.
The United Nations Programme in Public Administration: reinventing itself to help reinvent public administration:

In a world that is changing rapidly and constantly, public administration needs to be able to respond as rapidly and as effectively as possible to new challenges and priorities. The process of rein...
Marketing controls and employee responses: The moderating role of task characteristics

A key concern in implementing organizational controls is that little is known about when controls lead to “negative” employee responses. Previous research has suggested that lower levels of negative responses will be observed only if the controls that are being employed “fit” the characteristics of the tasks being controlled. The two task characteristics usually referred to include performance (outcome) documentation and procedural (cause-effect) knowledge. Unlike previous studies, however, this study assumes that the two task characteristics should have a joint, rather than independent, influence on employee responses to controls. The reason is that knowledge of how well one is doing is not sufficient for expecting lower levels of negative responses if information on procedures that may lead to better performance is not available. Knowledge of procedures, likewise, is not sufficient for lower levels of negative responses if performance documentation is not available. Results of an empirical study provide general support for the above line of reasoning.
Galactosamine hepatotoxicity: effect of galactosamine on glutathione resynthesis in rat primary hepatocyte cultures.

Abstract The effect of galactosamine on the resynthesis of glutathione in rat primary hepatocyte cultures was investigated. Cultured rat hepatocytes were treated with galactosamine (4 m m ) 1.5 hr prior to, concurrent with, or 1.5 hr after cell attachment; total cellular glutathione was then measured over time. Addition of galactosamine at any of these times suppressed methionine-enhanced glutathione resynthesis in the cultures after a lag period of about 120 min. The lag period was not due to slow uptake of galactosamine by the cultured cells, since cellular UTP levels fell to less than 10% of controls within 60 min, a time frame comparable to that observed in vivo . Neither was the lag period a result of interference with cellular uptake of methionine or with conversion of methionine to cysteine, since the phenomenon was observed regardless of whether methionine or cysteine was used to promote glutathione resynthesis. Addition of uridine, which protects against galactosamine hepatotoxicity in vivo by replenishing hepatic UTP levels, did not prevent the suppression of glutathione resynthesis. The data indicate that (a) galactosamine inhibits the time-dependent resynthesis of glutathione in primary hepatocyte cultures, (b) a lag period exists for this response, and (c) this effect is not directly related to depletion of cellular UTP stores.
The Cybotactic Condition of Ethyl Ether in the Region of the Critical Point

X-ray diffraction-ionization current curves have been taken at thirty-seven combinations of values of pressure, temperature and specific volume in the neighborhood of the critical point of ethyl ether. The results have been interpreted on the basis of the cybotactic view of molecular organization in liquids. It has been found that the groups are very sensitive to changes in specific volume but show much less dependence on temperature and pressure; that the groups disappear at approximately the same specific volume at various values of temperature and pressure; that groups may appear in the gaseous state; and that beyond a certain specific volume no groups appear and the curves are of the gas type. Using the cybotactic view one secures a rather definite picture of what occurs in fluid in the neighborhood of its critical point.
Coherent interference in multiplex CARS measurements: nonresonant susceptibility enhancement due to laser breakdown

A coherent interference with multiplex CARS signals is observed. This effect appears when coal fly ash particles are injected into the combustion flow being probed. The interference has the same spectral characteristics of the Stokes broadband dye laser shifted to anti-Stokes frequencies and is correlated with weak particle-induced laser breakdown. Analysis indicates the phenomenon is due to the enhancement of the nonresonant susceptibility in the small volume of the discharge plasma.
Curriculum beyond school walls: Implications of transition education

Faced with a decline in market competitiveness, a more diverse workforce, and rapid technological advances, American business and industry is in the process of restructuring (Boyett & Conn, 1992; Johnston & Packer, 1987). One aspect of this restructuring is providing workers with training. Over 30 billion dollars are spent each year to provide this training (Carnevale & Gainer, 1989). This level of commitment to the training of workers indicates a belief that if lasting change is to occur, workers must take an active role in the restructuring of business and industry. Table 1 lists the skills that employers want employees to possess called Workplace Basics (Carnevale, Gainer, & Meltzer, 1990).
Growth and Magnetic Resonance Characteristics of Human Squamous Cell Carcinoma Xenografts Implanted with Cells Suspended in MatrigelTM

Growth and magnetic resonance characteristics of a human squamous cell carcinoma SQ20B were studied in vivo as xenografts in nu/nu nude mice. Tumor cells injected subcutaneously in the flank using either MatrigelTM (MTG, an extract of basement membrane proteins) or growth medium (GM) as a vehicle were compared. Much higher tumor growth rates and cell density were observed with MatrigelTM than with GM implantation. Histology also showed that MTG implanted cells grew as vascularized solid tumors compared to GM tumors which formed cysts. As a result of increased cell density with the improved method, tumors as small as 0.3 cm3 provide high S/N magnetic resonance spectra which yield smaller standard deviations with fewer experiments.
Small Maf (MafG and MafK) Proteins Negatively Regulate Antioxidant Response Element-mediated Expression and Antioxidant Induction of the NAD(P)H:Quinone Oxidoreductase1 Gene

The antioxidant response element (ARE) is known to regulate expression and induction of NQO1, GST Ya, and other detoxifying enzyme genes in response to antioxidants and xenobiotics. The nuclear transcription factor Nrf2 and Nrf1 bind to the ARE and positively regulate expression and induction of the NQO1 and GST Ya genes. In this study, we demonstrate that overexpression of small Maf (MafG and MafK) proteins negatively regulate ARE-mediated expression and tert-butyl hydroquinone induction of the NQO1 and GST Ya genes in transfected Hep-G2 cells. In similar experiments, overexpression of small Maf proteins also repressed Nrf2-mediated up-regulation of ARE-mediated NQO1 and GST Ya genes expression in Hep-G2 cells co-transfected with Nrf2 and small Maf proteins. Band and supershift assays with the NQO1 gene ARE and nuclear proteins demonstrate that small MafG and MafK bind to the ARE as Maf-Maf homodimers and Maf-Nrf2 heterodimers. Therefore, Maf-Maf homodimers and possibly Maf-Nrf2 heterodimers play a role in negative regulation of ARE-mediated transcription and antioxidant induction of NQO1 and other detoxifying enzyme genes. In contrast to Maf-Nrf2, the Maf-Nrf1 heterodimers failed to bind with the NQO1 gene ARE and did not demonstrate the repressive effect in transfection assays.
Argon Laser Photodynamic Therapy of Human Corneal Neovascularization After Intravenous Administration of Dihematoporphyrin Ether

Purpose Long-term evaluation of dihematoporphyrin ether (DHE) safety and efficacy as photodynamic therapy (PDT) for patients with corneal neovascularization (KNV). Design Prospective multi-center interventional case series. Methods Seven patients were enrolled after Institutional Review Board approval and a detailed informed consent were obtained. Eligible patients presented with clinically stable KNV without active vessel progression or inflammation. All patients with severe hypertension, history of renal or hepatic disease, or sensitivity to porphyrins, and those with active keratitis or uncontrolled ocular surface disease were excluded. DHE was administered as an intravenous bolus (2 mg/kg). Seventy-two hours later, PDT was carried out using argon green laser (514 nm). The main outcome measure, extent of vascular thrombosis, was estimated during postoperative follow-up examinations performed at day 1, 1 week, 6 months, and up to 12 years postoperative. Results All patients obtained an immediate reduction in measurable corneal vascularization. With at least 6 months of follow-up, six of seven patients maintained a significant reduction (52.5% ± 19.6%, P Conclusions Intravenous DHE followed by photodynamic treatment in humans is effective for the reduction of inactive, established KNV. However, the significant short-term adverse effects related to systemic administration of this drug are of particular concern and warrant further investigation.
Near vs. Far Field: Interference Aggregation in TV Whitespaces

We investigate the behavior of aggregate interference generated by cognitive radios. We find that a phase change occurs in the behavior of aggregate interference as the density of the white-space devices is increased for a fixed protection radius. For a deterministic grid model, the mean of the interference behaves differently depending on whether the problem is one of ``near field'' or ``far field''. For a more realistic Poisson-placement model, we show that the shape of the distribution of interference changes from a heavy-tailed distribution to something that is approximately Gaussian. Investigating models with random fading of signal at each transmitter, we show that fading can alter the boundary of near and far fields. These phase-changes suggest that in designing rules for whitespace devices, the FCC rules may have to be sensitive to whether the situation is one of near or far field. For Poisson placement of nodes, our results also suggest that central limit theorem-style arguments might help in obtaining a conceptually and computationally improved understanding of interference aggregation.
Effect of Bedding Thickness on Behavior of Rigid Pipes as Determined by Using Numerical Crack Modeling

Numerical analyses are performed to find the loading capacity of buried reinforced concrete pipes at different performance levels. Different geometrical and material parameters play an important role in the total behavior of the pipe system. The effects of bedding thickness, middlebedding compaction level, steel cages, and pipe thickness are studied by using dynamic nonlinear analysis capable of modeling the complex cracking behavior of the concrete pipes. Contact elements are used for modeling the actual contact behavior between the pipe's surface and its surrounding soil. The Drucker-Prager plasticity model and the isotropic hardening plasticity model were used for soil and steel materials, respectively. Two structural performance levels are defined for pipes, the first one being the instance in which the crack initiates in the pipe's surface. The second-higher performance level is defined as the time in which the crack opens. The results of the study show that increasing the bedding thickness has a sig...
Metabolic Basis for Susceptibility and Resistance to Aflatoxin B1 Hepatocarcinogenesis in Rodents

AbstractHepatocarcinogen, aflatoxin B1 (AFB1), undergoes metabolic activation via epoxidation and the interaction of this epoxide with DNA is believed to be responsible for its initiation of carcinogenesis. Several in vitro and in vivo studies suggest that epoxidation alone cannot account for differences in AFB1-DNA binding and carcinogenicity observed in rats (susceptible species) and hamsters (resistant). Recent work from my laboratory on AFB1 metabolism with hepatocellular fractions and isolated hepatocytes from rats and hamsters has been reviewed. These studies indicate that cytosolic glutathione (GSH) S-transferases play an important role in the modulation of hepatic AFB1-DNA binding. Inhibition of hepatocarcinogenesis and AFB1-DNA binding by pretreatment of rats with various inducers are discussed. Even though phenobarbital (PB) is an inducer of both cytochrome P-450 and GSH S-transferases, the subcellular, hepatocyte and in vivo data suggest that induced levels of GSH S-transferases are largely res...
Manifestations of coronary atherosclerosis in young trauma victims--an autopsy study.

Abstract Objectives . The aim of this study was to look at the prevalence of coronary atherosclerosis, its severity aid site of involvement in patients Background . Autopsies performed on casualties of the Korean War revealed coronary artery involvement in 77.3% of the hearts studied, and data after the Vietnam War noted the presence of atherosclerosis in 45% of casualties with severe disease in 5%, suggesting a decline in the prevalence of coronary atherosclerosis in young men. Methods . One hundred eleven victims of noncardiac trauma (86.4% white with a mean age of 26 ± 6 years) underwent pathologic examination of their coronary arteries to estimate the presence and severity of coronary atherosclerosis grossly, microscopically and through computerized planimetry. Identified segments of the coronary arteries were sectioned at 3-mm intervals, stained with special stains and after microscopic examination transferred to videotape and digitized to allow estimation of the percent compromise in the lumen area by atherosclerotic plaque. Results . Signs of coronary atherosclerosis were seen in 78.3% of the total study group, with >50% narrowing in 20.7% and >75% narrowing in 9%. No demographic or anatomic features seperated the groups with less or more severe involvement of their coronary arteries. Proximal involvement was more common except in the right coronary artery, which was as frequently involved distally. Conclusions . The overall prevalence of coronary atherosclerosis in a young, predominantly study group was comparable with that noted after the Korean War. Left main or significant two- and three-vessel involvement was noted in 20% of the group studied and emphasizes the need for aggressive risk factor modification in this group.
Replication enhancer-independent mutation increases the co-operativity with which an initiator protein binds its origin

The plus-strand replication origin of bacteriophage fl has a bipartite structure consisting of a required core origin region and an adjacent A + T-rich enhancer sequence that potentiates replication approximately 100-fold. The core origin binds the initiator protein (gpII) and the enhancer binds the Escherichia coli integration host factor (IHF). gpII binds the core origin in two steps, forming a binding intermediate (complex I) and a functional complex for nicking (complex II). We have used a double-label gel binding assay to determine the stoichiometry of the gpII-origin interaction. The results indicate that complex I contains two gpII molecules per origin, and complex II contains four gpII molecules per origin. Enhancer-independent mutations in gpII allow wild-type levels of replication in the absence of either the enhancer or IHF. We have examined the binding of an enhancer-independent gpII mutant (mp1) protein to the replication origin. The mp1 mutation in gpII (Met40----Ile) increases the co-operativity with which the protein binds to form complex II. In addition, the mutant gpII forms both complexes with a DNA fragment containing only two (beta-gamma) of the three repeats from the core origin sequence, while the wild-type protein forms only complex I with this fragment. We discuss how a mutation that increases the co-operativity of binding of an initiator protein might stimulate DNA replication.
Magnetic ordering and magnetization in the high-temperature superconductor ErBa2Cu

Low-temperature heat-capacity, electrical resistivity, and magnetization measurements are performed to investigate the superconducting and magnetic behavior of ErBa/sub 2/Cu/sub 3/O/sub 7-//sub x/. This compound exhibits a superconducting transition at 84 K as determined from zero resistance and Meissner effect. A well-defined magnetic transition is seen at 0.87 K from heat-capacity measurements. We deduce the coexistence of superconductivity and antiferromagnetic order in this compound; however, magnetization data show that the paramagnetism from Er/sup 3+/ and superconductivity are independent, leading to indirect evidence of extremely anisotropic superconductivity in this class of compounds.
The National Academy of Kinesiology 2010 Review and Evaluation of Doctoral Programs in Kinesiology

In 2010, the National Academy of Kinesiology (NAK) conducted its second national doctoral program survey, based on faculty and student data from 2005 to 2009. Total T-scores for each school were derived from the sum of nine faculty indices and seven student indices. Faculty indices, based on research, presentations, grants, and honors, made up 66%, and student indices based on GRE scores, financial support, admission/acceptance characteristics, national quantitative scores and employment, made up 34% of the Total T-scores. Two rankings of these Total T-scores for the doctoral programs are presented: unadjusted and adjusted for faculty and student size. Total T-scores for each index for each school and the aggregate research funds expended by all schools are provided. These rankings are compared with those from the NAK 2005 survey and also to a ranking derived by the authors from published scores in the 2010 National Research Council doctoral program evaluation.
Quantifying the financial impacts of net-metered PV on utilities and ratepayers

Abstract Deployment of customer-sited photovoltaics (PV) in the United States has expanded rapidly in recent years, driven by falling PV system prices, the advent of customer financing options, and various forms of policy support at the federal, state, and local levels. With the success of these efforts, heated debates have surfaced in a number of U.S. states about the impacts of customer-sited PV on utility shareholders and ratepayers. We performed a scoping analysis using a financial model to quantify the financial impacts of customer-sited PV on utility shareholders and ratepayers and to assess the magnitude of these impacts under alternative utility conditions. We find that customer-sited PV generally reduces utility collected revenues greater than reductions in costs leading to a revenue erosion effect and lost future earnings opportunities. We also find that average retail rates increase as utility costs are spread over a relatively smaller sales base. We analyze these results under various assumptions about utility operating and regulatory environments and find that these impacts can vary greatly depending upon the specific circumstances of the utility. Based on this analysis, we highlight potential implications for policymakers and identify key issues warranting further analysis.
Limits of specific contact resistivity to Si, Ge and III-V semiconductors using interfacial layers

Specific contact resistivities of source/drain contacts employing interfacial layers are calculated with simulations of tunneling transport. Fermi level depinning, dipoles, and other techniques for barrier lowering are explored. Interfacial materials with the potential to meet future contact resistivity requirements are identified for silicon and high-mobility alternatives.
Uroplakins Ia and Ib, two major differentiation products of bladder epithelium, belong to a family of four transmembrane domain (4TM) proteins

The mammalian bladder epithelium elaborates, as a terminal differentiation product, a specialized plasma membrane called asymmetric unit membrane (AUM) which is believed to play a role in strengthening and stabilizing the urothelial apical surface through its interactions with an underlying cytoskeleton. Previous studies indicate that the outer leaflet of AUM is composed of crystalline patches of 12-nm protein particles, and that bovine AUMs contain three major proteins: the 27- to 28-kD uroplakin I, the 15-kD uroplakin II and the 47-kD uroplakin III. As a step towards elucidating the AUM structure and function, we have cloned the cDNAs of bovine uroplakin I (UPI). Our results established the existence of two isoforms of bovine uroplakin I: a 27-kD uroplakin Ia and a 28-kD uroplakin Ib. These two glycoproteins are closely related with 39% identity in their amino acid sequences. Hydropathy plot revealed that both have four potential transmembrane domains (TMDs) with connecting loops of similar length. Proteolytic digestion of UPIa inserted in vitro into microsomal vesicles suggested that its two main hydrophilic loops are exposed to the luminal space, possibly involved in interacting with the luminal domains of other uroplakins to form the 12-nm protein particles. The larger loop connecting TMD3 and TMD4 of both UPIa and UPIb contains six highly conserved cysteine residues; at least one centrally located cysteine doublet in UPIa is involved in forming intramolecular disulfide bridges. The sequences of UPIa and UPIb (the latter is almost identical to a hypothetical, TGF beta-inducible, TI-1 protein of mink lung epithelial cells) are homologous to members of a recently described family all possessing four transmembrane domains (the "4TM family"); members of this family include many important leukocyte differentiation markers such as CD9, CD37, CD53, and CD63. The tissue-specific and differentiation-dependent expression as well as the naturally occurring crystalline state of uroplakin I molecules make them uniquely suitable, as prototype members of the 4TM family, for studying the structure and function of these integral membrane proteins.
Assessing transferable residues from intermittent exposure to flea control collars containing the organophosphate insecticide chlorpyrifos

Children can be exposed to pesticides from numerous residential sources such as carpet, house dust, toys and clothing from treated homes, and flea control remedies on pets. In the present studies, 48 pet dogs (24 in each of two studies) of different breeds and weights were treated with over-the-counter flea collars containing chlorpyrifos (CP), an organophosphorus insecticide. Transferable insecticide residues were quantified on cotton gloves used to rub the dogs for 5 min and on cotton tee shirts worn by a child (Study 2 only). First morning urine samples were also obtained from adults and children in both studies for metabolite (3,5,6-trichloro-2-pyridinol) quantification. Blood samples were obtained from treated dogs in Study 1 and plasma cholinesterase (ChE) activity was monitored. Transferable residues on gloves for all compounds were highest near the neck of the dogs and were lowest in areas most distant from the neck. Rubbing samples (over the collar) at two weeks post-collar application contained 447±57 μg CP/glove while samples from the fur of the back contained 8±2 μg CP/glove. In Study 2, cotton tee shirts worn by children at 15 days post-collar application for 4 h showed CP levels of 134±66 ng/g shirt. There were significant differences between adults and children in the levels of urinary metabolites with children generally having higher urinary levels of metabolites than adults (grand mean±SE; 11.6±1.1 and 7.9±0.74 ng/mg creatinine for children and adults, respectively, compared to 9.4±0.8 and 6.9±0.5 ng/mg creatinine before collar placement). Therefore, there was little evidence that the use of this flea collar contributed to enhanced CP exposure of either children or adults.
Up-regulation of macrophage inflammatory protein-2 and complement 3A receptor by the trichothecenes deoxynivalenol and satratoxin G

The trichothecenes are a group of mycotoxins that target leukocytes and have a wide range of immunomodulatory effects. Differential display analysis was applied to assess the effects of the trichothecenes deoxynivalenol (vomitoxin, DON) and satratoxin G (SG), on mRNA in the RAW 264.7 macrophage cell line. Cells were incubated with DON (1 microg/ml) or SG (5 ng/ml) for 2 h and total RNA then subjected to RT-PCR with a set of oligo(dT) primers. Resultant cDNA was amplified using an oligo (dT) downstream primer and an arbitrary decanucleotide upstream primer to make 35S-labeled PCR products. After separation of the products in denaturing polyacrylamide gel, 23 differentially expressed cDNA fragments were isolated and sequenced. Two of these were identified as known genes, namely, macrophage inflammatory protein-2 (MIP-2), a potent neutrophil chemoattractant involved in tissue injury and inflammation, and complement 3a receptor (C3aR), a proinflammatory mediator. Both MIP-2 and C3aR mRNAs were up-regulated by DON while only MIP-2 mRNA was induced by SG. Using commercially available antibodies, MIP-2 protein was also found to be induced by both DON and SG in RAW 264.7 cell cultures. When mice were treated with DON (12.5 mg/kg), splenic MIP-2 mRNA and serum MIP-2 levels were increased. MIP-2 mRNA and serum MIP-2 levels were synergistically increased when mice were co-treated with DON and LPS. Up-regulation of MIP-2 and C3aR are consistent with previous reports of trichothecene-induced inflammatory gene up-regulation and suggest that the specific genes affected may depend on trichothecene structures.
Design, Synthesis, and Catalytic Properties of Silica-Supported, Pt-Promoted Iron Fischer–Tropsch Catalysts

Silica-supported iron catalysts (Fe/SiO2, FePt/SiO2, and FePtK/SiO2) were prepared using a novel nonaqueous (acetone) evaporative deposition technique. This preparation leads to relatively well-dispersed iron phases at modest (10%) metal loadings. Moreover, catalytic activities of these catalysts for Fischer–Tropsch synthesis are high and comparable to industrially relevant precipitated iron catalysts. Catalyst activities were tested following a nonregular L18 orthogonal array that enabled the number of 150-h activity tests to be reduced from 54 to 18; this statistical design was augmented with five additional runs to provide replication. Primary independent variables affecting catalysts' activity were promoter type, pretreatment gas composition (H2, H2/CO, or CO), pretreatment temperature (250, 280, or 320 °C), and reaction temperature (250 or 265 °C); iron carbide level measured from Mossbauer spectroscopy was correlated with activity in a separate analysis. Activity was found to increase in the order Fe/SiO2, FePt/SiO2, and FePtK/SiO2. For a given catalyst composition, activity increases to a maximum with increasing pretreatment temperature and increasing time. Catalyst activity was also positively correlated with increasing chi-carbide content for Fe/SiO2 and FePt/SiO2 catalysts but not for FePtK/SiO2. While pretreatment atmosphere greatly influences initial activity–time behavior, activity is less dependent on pretreatment after about 150 h of reaction. Steady-state methane and C2+ hydrocarbon selectivities (CO2-free basis) for the FePtK/SiO2 catalyst at 250–265 °C, 10 atm, and H2/CO = 1 are 7–9 and 91–93%, respectively, while its hydrocarbon productivity at 250 °C (normalized to 15 atm, H2/CO = 0.7) of 0.27 g HC/gcat/h is comparable to those reported for unsupported precipitated iron catalysts of high activity and selectivity. These results indicate that preparation of an active, selective, stable, attrition-resistant supported iron catalyst for Fischer–Tropsch synthesis is feasible. Promise for additional improvements in catalyst performance through application of advanced preparation methods and optimization of catalyst chemical and physical properties is also indicated.