cssi/SciSciGPT-SciSciNet huggingface dataset:
Steady-State Hydrodynamic Lubrication Modeled With the Payvar-Salant Mass Conservation Model

Steady-state smooth surface hydrodynamic lubrications of a pocketed pad bearing, an angularly grooved thrust bearing, and a plain journal bearing are simulated with the mass-conservation model proposed by Payvar and Salant. Three different finite difference schemes, i.e., the harmonic mean scheme, arithmetic mean scheme, and middle point scheme, of the interfacial diffusion coefficients for the Poiseuille terms are investigated by using a uniform and nonuniform set of meshes. The research suggests that for the problems with continuous film thickness and pressure distributions, the results obtained with these numerical schemes generally well agree with those found in the literatures. However, if the film thickness is discontinuous while the pressure is continuous, there may be an obvious deviation. Compared with both the analytical solution and other two schemes, the harmonic mean scheme may overestimate or underestimate the pressure. In order to overcome this problem artificial nodes should be inserted along the wall of the bearings where discontinuous film thickness appears. Moreover, the computation efficiency of the three solvers, i.e., the direct solver, the line-by-line the tridiagonal matrix algorithm (TDMA) solver, and the global successive over-relaxation (SOR) solver, are investigated. The results indicate that the direct solver has the best computational efficiency for a small-scale lubrication problem (around 40 thousand nodes). TDMA solver is more robust and requires the least storage, but the SOR solver may work faster than TDMA solver for thrust bearing lubrication problems. Numerical simulations of a group of grooved thrust bearings were conducted for the cases of different outer and inner radii, groove depth and width, velocity, viscosity, and reference film thickness. A curve fitting formula has been obtained from the numerical results to express the correlation of load, maximum pressure, and friction of an angularly grooved thrust bearing in lubrication.
Stochastic-based accuracy of data reconciliation estimators for linear systems

Abstract Accuracy of an instrument has been traditionally defined as the sum of the precision and the bias. Recently, this notion was generalized to estimators [Bagajewicz, M. (2005a). On the definition of software accuracy in redundant measurement systems. AIChE Journal , 51 (4), 1201–1206]. The definition was based on the maximum undetected bias and ignored the frequency of failure, thus providing an upper bound. In more recent work [Bagajewicz, M. (2005b). On a new definition of a stochastic-based accuracy concept of data reconciliation-based estimators. In European Symposium on Computer-Aided Process Engineering Proceeding (ESCAPE) ], a more realistic concept of expected value of accuracy was presented. However, only the timing of failure and the condition of failure was sampled. In this paper we extend the Monte Carlo simulations to also sample the size of the gross errors and we provide new insights on the evolution of biases through time.
Myofascial pain syndrome and trigger-point management

Background and Objectives. Myofascial pain syndrome (MPS) is a common condition often resulting in referral to a pain clinic. The epidemiology, pathogenesis, and various diagnostic tools are reviewed, and a variety of treatment methods are discussed. Methods. Extensive periodical literature and textbooks are reviewed, and selected manuscripts are critically analyzed. Results. The incidence of MPS with associated trigger points appears to vary between 30 and 85% of people presenting to pain clinics, and the condition is more prevalent in women than in men. Patients complain of regional persistent pain, ranging in intensity and most frequently found in the head, neck, shoulders, extremities, and low back. Muscle histologic abnormalities have been described in some studies. Similarly, electromyographic, themographic, and pressure algometric studies have inconsistently identified abnormalities. A multidisciplinary approach to treatment appears to be most beneficial and may include such modalities as trigger-point injections, dry needling, stretch and spray, and transcutaneous electrical nerve stimulation. Conclusions. The definitive pathogenesis of MPS is currently unknown, and no single diagnostic method is consistently positive. While trigger-point injection is the most widely employed method of treatment, other modes of therapy have also proved to be effective.
Interaction of calcium with microsomes: a modified method for the rapid isolation of rat liver microsomes.

The addition of 8 mM Ca++ to a dilute post-mitochondrial supernatant of rat liver allows the isolation of the microsomal fraction by centrifugation at 30 xg for 10 minutes. The yield of microsomal protein and phospholipids is comparable to that obtained by centrifuging the untreated supernatant at 105,000 xg for one hour. The composition and functional activities of the membranes isolated by both methods are also similar. This method circumvents the need for an ultracentrifuge and results in a saving of time, particularly when multiple washes are necessary.
Oxidation of Bilirubin by Rat Brain Mitochondrial Membranes—Genetic Variability☆

Abstract Bilirubin is oxidized by brain mitochondrial membranes at a rate which may contribute significantly to clearance of bilirubin from brain. Different strains of congenitally jaundiced rats (Gunn rats) vary widely as far as the mortality rate of the homozygous (jaundiced) pups. Because the ability to oxidize bilirubin in brain may protect against toxicity, we hypothesized that the ability to oxidize bilirubin would be lower in Gunn rat strains (ACI/N-j) with a high mortality rate in the homozygous pups. Mitochondria were obtained from young rat brains by differential centrifugation in sucrose gradients. The mitochondria were ruptured by sonication. The change in optical density of a bilirubin solution at 440 nm was measured over time following addition of the membrane suspension. The rate of bilirubin oxidation was significantly lower in rats of the RHA/N-j strain both at 7–8 days of age and in adults, compared to rats of the ACI/N-j and the Sprague-Dawley strains at the same age points. Differences in mortality rates between the RHA/N-j and the ACI/N-j strains of Gunn rats could not be explained on the basis of differences in the ability of brain mitochondrial membranes to oxidize bilirubin, as these activities were lower in the RHA/N-j rats, which also have lower mortality rates, but higher in the ACI/N-j rats, which have remarkably high mortality rates. This study also confirmed previous findings relative to age maturation of the enzyme activity.
Acute Kidney Injury After Cardiac Surgery: Does the Time Interval From Contrast Administration to Surgery Matter?

Objective The authors sought to evaluate the association between the time interval from contrast administration to cardiac surgery and postoperative acute kidney injury (AKI). Design A retrospective observational study over a 1-year period. Setting A US academic medical institution. Participants Six hundred forty-four adult patients undergoing nonemergent cardiac surgery. Interventions No interventions were performed as part of the study. Measurements and Main Results AKI was defined as an increase in serum creatinine by ≥0.3 mg/dL or ≥50% above baseline within the first 2 postoperative days or the commencement of renal replacement therapy within the same period. Using a contrast-to-surgery time interval >7 days as the baseline, multivariable logistic regression analysis determined the association between a contrast-to-surgery time interval ≤1 day or 2 to 7 days and postoperative AKI adjusting for potential confounding variables. The incidence of AKI within the study cohort was 21.9%. After adjusting for other covariates, there was no association between the contrast-to-surgery time and AKI (odds ratio [OR] ≤1 day = 0.93; 95% confidence interval [CI], 0.52-1.66; p = 0.81; OR = 2-7 days = 1.28; 95% CI, 0.78-2.11; p = 0.34). Conclusions In an appropriately selected population, cardiac surgery can be performed within 1 day of cardiovascular catheterization and contrast administration without an increase in the incidence of postoperative AKI. Recommendations to delay cardiac surgery for a specified period after contrast administration to reduce the risk of postoperative AKI are premature. Additional evidence is required before making recommendations on optimal surgical timing after contrast exposure.
Document Clustering via Matrix Representation

Vector Space Model (VSM) is widely used to represent documents and web pages. It is simple and easy to deal computationally, but it also oversimplifies a document into a vector, susceptible to noise, and cannot explicitly represent underlying topics of a document. A matrix representation of document is proposed in this paper: rows represent distinct terms and columns represent cohesive segments. The matrix model views a document as a set of segments, and each segment is a probability distribution over a limited number of latent topics which can be mapped to clustering structures. The latent topic extraction based on the matrix representation of documents is formulated as a constraint optimization problem in which each matrix (i.e., a document) A_i is factorized into a common base determined by non-negative matrices L and R^\top, and a non-negative weight matrix M_i such that the sum of reconstruction error on all documents is minimized. Empirical evaluation demonstrates that it is feasible to use the matrix model for document clustering: (1) compared with vector representation, using matrix representation improves clustering quality consistently, and the proposed approach achieves a relative accuracy improvement up to 66\% on the studied datasets, and (2) the proposed method outperforms baseline methods such as k-means and NMF, and complements the state-of-the-art methods like LDA and PLSI. Furthermore, the proposed matrix model allows more refined information retrieval at a segment level instead of at a document level, which enables the return of more relevant documents in information retrieval tasks.
Voluntariness and Causality

Etude de la theorie thomiste de la responsabilite morale fondee sur la notion de volontariat. Examinant la definition de l'acte volontaire en fonction de sa cause directe ou indirecte chez Saint Thomas d'Aquin, l'A. s'interesse aux cas des omissions par negligence qui ne relevent ni de la planification ni de la prediction et qui ne permettent pas d'attribuer du merite ou un blâme a leur agent. Remettant en question le caractere volontaire d'une action que l'agent est oblige de faire, et distinguant les notions de cause en soi et cause accidentelle, l'A. montre que l'omission est un acte volontaire en ce sens que l'agent manque a son pouvoir de planification
Developmental effects of the ay substitution on mouse activity level.

Short-term activity level was tested with inbred mice of four genotypes in an open-field apparatus. These data supplement earlier results for long-term exploratory activity using the same genetic stocks. The results indicate that the effects of Ay in suppressing locomotor activity are not restricted to long-term experimentation nor to a specific apparatus in mature (125 day old) Ss. Different results are found at each of the three age levels studied, however. The interpretation utilizes indirect evidence from earlier strain-difference studies and is open to experimental challenge. It is also noted that components of sexual and agonistic behavior patterns may provide stable phenotypes for behavior-genetic investigation.
Dma1 Prevents Mitotic Exit and Cytokinesis by Inhibiting the Septation Initiation Network (SIN)

In the fission yeast Schizosaccharomyces pombe, the septation initiation network (SIN) triggers cytokinesis after mitosis. We investigated the relationship between Dma1p, a spindle checkpoint protein and cytokinesis inhibitor, and the SIN. Deletion of dma1 inactivates the spindle checkpoint and allows precocious SIN activation, while overexpressing Dma1p reduces SIN signaling. Dma1p seems to function by inhibiting the SIN activator, Plo1p kinase, since dma1 overexpression and deletion phenotypes suggest that Dma1p antagonizes Plo1p localization. Furthermore, failure to maintain high cyclin-dependent kinase (CDK) activity during spindle checkpoint activation in dma1 deletion cells requires Plo1p. Dma1p itself localizes to spindle pole bodies through interaction with Sid4p. Our observations suggest that Dma1p functions to prevent mitotic exit and cytokinesis during spindle checkpoint arrest by inhibiting SIN signaling.
Radiation-induced defects in LiAlO2 crystals: Holes trapped by lithium vacancies and their role in thermoluminescence

Abstract Electron paramagnetic resonance (EPR) is used to identify the primary hole trap in undoped lithium aluminate (LiAlO2) crystals. Our interest in this material arises because it is a candidate for radiation detection applications involving either optically stimulated luminescence (OSL) or thermoluminescence (TL). During an x-ray irradiation at room temperature, holes are trapped at oxygen ions adjacent to lithium vacancies. Large concentrations of these lithium vacancies are introduced into the crystal during growth. With the magnetic field along the [001] direction, the EPR spectrum from these trapped-hole centers consists of eleven lines, evenly spaced but with varying intensities, caused by nearly equal hyperfine interactions with two 27Al nuclei (I=5/2, 100% abundant). The g matrix is determined from the angular dependence of the EPR spectrum and has principal values of 2.0130, 2.0675, and 2.0015. These g shifts strongly support the model of a hole in a p orbital on an oxygen ion. The adjacent lithium vacancy stabilizes the hole on the oxygen ion. A sequence of pulsed thermal anneals above room temperature shows that the EPR spectrum from the holes trapped adjacent to the lithium vacancies disappears in the 90–120 °C range. The thermal decay of these hole centers directly correlates with an intense TL peak near 105 °C. Signals at lower magnetic field in the 9.4 GHz EPR spectra suggest that the electron trap associated with this TL peak at 105 °C may be a transition-metal-ion impurity, most likely Fe, located at a cation site. Additional less intense TL peaks are observed near 138, 176, and 278 °C.
Evaluating the Relationship Between the Carbon and Sulfur Cycles in the Later Cambrian Ocean: An Example from the Port au Port Group, Western Newfoundland, Canada

Abstract We present a high-resolution δ 34 S (sulfate and pyrite) and δ 13 C carbonate record from the Middle–Upper Cambrian Port au Port Group, a mixed carbonate-siliciclastic succession exposed in western Newfoundland, Canada. The results illustrate systematic δ 34 S sulfate shifts of > 15‰ over relatively short stratigraphic intervals (10 m, likely 34 S sulfate–pyrite (ca. 23‰) and a generally positive coupling between changes in δ 13 C carbonate and δ 34 S sulfate . Together, these results indicate that Middle to Late Cambrian sulfate concentrations were low and that the sulfate reservoir was more sensitive to change than it was in either terminal Neoproterozoic or Cenozoic oceans. However, a simple carbon (C) and sulfur (S) isotope box model of the Late Cambrian ocean illustrates that low sulfate concentrations alone fail to account for the > 15‰ δ 34 S sulfate shifts recognized in Port au Port strata. Such large shifts can be generated only if fluctuating oceanic redox is invoked; marine anoxia forces reduced C/S burial and elevated Δ 34 S, driving larger δ 34 S changes per mole of organic carbon buried. The conclusion that later Cambrian oceans featured both low sulfate levels and widespread subsurface anoxia supports hypotheses that link fluctuating marine redox conditions in the delayed recovery of skeletal animals and metazoan reefs from late Early Cambrian extinction.
Social behavior of children in a classroom setting

Abstract Forty-two children (25 boys, 17 girls) in two traditional second-grade classrooms were videotaped during normal classroom activity until approximately 50 min of tape was accumulated for each child. A variety of behaviors was then coded on an event recorder, including child-child interactions, general behaviors, and child-teacher interactions. Teacher evaluations expressed as ratings between bipolar adjectives were also obtained. A principal components analysis revealed six distinct factors. The strongest factor was composed of teacher-child interactions. Analyses of variance indicated that sex and birth order differences were limited. Compared to boys, girls engaged in more verbalization with same-sex peers (p
High-current triode with nonintercepting control electrode

A novel triode configuration suitable for high-density electron guns is described in which several insulated posts project through holes in the cathode surface. Results of a pilot high-power, pulsed-voltage experiment are given.
Crossing Content: A Strategy for Students with Learning Disabilities

Students with learning disabilities in the elementary grades, middle school, and secondary school have used Read, Imagine, Decide, and Do (RIDD) since 1996. The strategy was first developed to assist students when dealing with math word problems and to aid students in reading directions. In the following article, the author describes the strategy and provides a framework for practitioners to use throughout the curriculum. Information is included from previous studies, and the first lesson is described in detail.
Evaluation of pulsed gastric lavage on the survival of captive shovelnose sturgeon

Summary Little is known about the diet of the endangered pallid sturgeon, Scaphirhynchus albus. Because of this endangered status non-lethal methods to ascertain their food habits must be evaluated. Tests of pulsed gastric lavage (PGL) were conducted on shovelnose sturgeon S. platorynchus, as a surrogate for the pallid sturgeon, to determine if PGL negatively affected their survival. Nine sequential trials containing eight shovelnose sturgeon (N = 72) were conducted with wild fish collected from the Platte River near Louisville, Nebraska. Each trial group was placed into one of two tanks, with each tank containing three pulsed gastric lavaged fish and one control fish. Fish were weighed, measured, and tagged with a passive integrated transponder (PIT tag) before being transported to holding tanks for acclimation and PGL treatment. Sturgeon were acclimated 4–6 days prior to PGL, then held for 15 days after treatment. Temperature, dissolved oxygen, ammonia, and nitrite were monitored daily. No significant difference between the survival of PGL fish and control fish was detected. Because the test required these fish to endure the additional stress of transport and handling, PGL seems a viable technique that can be safely used to evaluate food habits of shovelnose sturgeon, and could be considered safe for pallid sturgeon food habit studies.
Evaluation of some parameters affecting the collection and analysis of midget impinger samples.

Coulter Counter techniques were used to determine the collection efficiency of the midget impinger for coal dust samples with isopropanol, ethanol, and water as the collecting fluids. The collection efficiency of the impinger with the alcohols and water was approximately 95% and 68%, respectively, for particles 1 micrometer and greater in diameter, and 77% and 64%, respectively, when the particle size range was expanded to include particles down to 0.68 micrometer in diameter. The midget impinger samples were also analyzed by standard microscopic techniques. Equivalent counts were not obtained for the two alcohols, indicating the effect fluid viscosity has on standard microscopic techniques. Samples counted in a controlled-temperature chamber, using the microscopic technique, showed a change in count of 2.4% and 1.2% per degree centigrade for isopropanol and ethanol, respectively.
Fine structure of lentoid bodies derived from normal and cataractous mouse lenses.

Lentoid bodies, aggregations of epithelial cells originating in cultures of lenses from normal and Nakano cataractous strain mice were studied by transmission and scanning electron microscopy. Cells of the lentoid body of the mouse lens epithelium tend to form random aggregations with marked degeneration in the central zone in contrast to the reported structure of the lentoid bodies of the chick. Although the appearances of cells constituting lentoid bodies of both normal and cataractous mice were similar, electron microscopic histochemistry revealed that there was a marked difference in the ATPase activity. The precipitate produced by the histochemical reaction where phosphate is released by the action of ATPase was abundantly present in the vicinity of cell membranes of lentoid body cells of the normal mouse, whereas it was absent in cells of Nakano strain mice. This is another demonstration that an ATPase inhibitor which is present in the lens of Nakano strain was carried into the cultured cells.
Government chief nursing officers' perceptions of barriers to using research on staffing.

Background: Current global healthcare problems include nursing shortages contributing to low nurse staffing. Low nurse staffing is associated with poor patient and nurse outcomes, but research utilization using these findings especially at the policy level remains slow. Research objective: To assess high-ranking government nurses’ perceptions of barriers to using research on nurse staffing. Methods: An electronic information message about the impact of nurse staffing was presented to government chief nursing officers (CNOs) from 110 countries. The CNOs’ perceptions of local barriers to utilizing these research findings were then assessed in an electronic survey. The four factors that influence the first two stages of Rogers’s five-stage model of diffusion were examined. The factors, characteristics of the adopter, organization, innovation and communication, were measured using an adapted version of the BARRIERS scale. Results: Barriers were present in all four characteristics. The top barrier was lack of reports and studies in one place. Other barriers were lack of cooperation within the organization and lack of awareness of the research findings. Differences according to Gross National Income were also noted. Conclusions: The CNOs and other health policy advisors can use the findings in planning for adequate nurse staffing. Development of electronic newsletters with summaries of pertinent research for CNOs and other policy advisors is needed. Future studies on nurse staffing are warranted. They should focus on other settings and how best to share research findings with policymakers.
In Search of Aggregation Pathways of IAPP and Other Amyloidogenic Proteins: Finding Answers through NMR Spectroscopy.

The deposition of aggregates of human islet amyloid peptide (hIAPP) has been correlated with the death of insulin-producing beta (β) cells in type II diabetes mellitus. The actual molecular mechanism of cell death remains unknown; however, it has been postulated that the process of aggregation and amyloid fibril growth from monomeric hIAPP is closely involved. Intermediate IAPP aggregates are highly toxic to islet cells, but lack of structural knowledge of these oligomers and complications in applying biophysical techniques to their study have been the main obstacles in designing structure-based therapeutics. Furthermore, the involvement of metal ions (Cu2+ and Zn2+) associated with hIAPP has demonstrated an effect on the aggregation pathway. In the absence of well-defined targets, research attempting to attenuate amyloid-linked toxicity has been substantially slowed. Therefore, obtaining high-resolution structural insights on these intermediates through NMR techniques can provide information on preventin...
Quantitative evaluation of the performance of an industrial benchtop enclosing hood.

Plain benchtop enclosing hoods are assumed to be highly effective in protecting workers from airborne contaminants, but there is little research published to support or rebut that assumption. The purpose of this research was to investigate the performance of a 36 in. wide, 30 in. high, and 40 in. deep benchtop enclosing hood. The study consisted of two parts: (1) investigating the effects of hood face velocity (five levels: 111, 140, 170, 200, and 229 ft/min) and wind tunnel cross-draft velocity (five levels: 14, 26, 36, 46, and 57 ft/min) on a plain benchtop enclosing hood, and (2) studying the effects of specific interventions (no-intervention, collar flange, bottom flange, cowling, and sash) added onto the same enclosing hood. A tracer gas method was used to study the hood's performance inside a 9 ft high, 12 ft wide, and 40 ft long wind tunnel. Freon-134a concentrations were measured at the mouth and nose of an anthropometrically scaled, heated, breathing manikin holding a source between its hands whi...
RNA Pseudoknot Folding Energy Landscape Elucidated with T-Jump Measurements and Kinetic Modeling

Pseudoknots are minimal tertiary motifs in RNA that are involved in many biological functions determined by their structure, stability and dynamics. They also stabilize the structures of several ribozymes and are often the rate-limiting step in their folding pathways. Although many studies have reported on pseudoknot stability, and theoretical and computational studies have proposed folding pathways for some pseudoknots, there are few experimental studies on pseudoknot folding kinetics. Therefore, a complete picture of how pseudoknots fold to achieve their functional structure is lacking.Here, we report folding kinetics of the VPK pseudoknot, a variant of the Mouse Mammary Tumor Virus (MMTV) pseudoknot, which is involved in ribosomal frameshifting. We combine rapid temperature-jump (T-jump) with time-resolved fluorescence spectroscopy, and global analysis of equilibrium and kinetics measurements, to elucidate the folding energy landscape. We use 2AP (a fluorescent analog of adenine) placed at different positons along the RNA sequence as a probe of RNA conformations, both under equilibrium conditions and in response to the T-jump perturbation. We also, independently, measure the equilibrium and folding kinetics of two hairpin structures that are believed to be intermediates in the folding pathways. The complete set of equilibrium and kinetics measurements on the pseudoknot and the two hairpins are described in a self-consistent manner in terms of a 4-state kinetic model and a minimal set of parameters. Our results provide the first experimental evidence of multiple parallel folding/unfolding pathways in RNA pseudoknots, as indicated by previous simulations studies.
Wonder Woman was Argentine and her Real Name was Evita

AbstractMost of what has been written about Eva Peron is generally accepted as historical reality, though it is not the result of rigorous scholarly research. This article analyzes some examples of Evita “myths” and attempts to explain their origin.
Morphology and interfacial structure of gamma precipitates in the beta phase of a Ti-Al-Nb-Zr alloy

The morphology and interfacial structure of γ precipitates in the β phase of a Ti-44%Al-4%Nb-4%Zr alloy have been studied using transmission electron microscopy. The γ precipitates exhibit an acicular morphology bounded by two principal facets and two minor facets. One of the major facets adopts a commensurate singular interface structure, which forms at an orientation close to the Kurdjumov-Sachs relationship. On an atomic scale these facets adopt a 'step-terrace' configuration, and the coherency strain on the terrace is relieved by the dislocation character of the steps. The other major facet adopts a one-dimensionally incommensurate singular interface structure at the Pitsch orientation relationship. The angular incompatibility between these two singular structures is accommodated by dislocations in the incommensurate interface. The configuration of these dislocations suggests that this is accomplished by nucleation at the facet junctions and subsequent climb along the facets.
U and Pu Liii XAFS of Pu-doped glass and ceramic waste forms

Abstract X-Ray Absorption Fine Structure (XAFS) spectroscopic studies were performed on a suite of compositionally identical Pu-doped simulated waste glasses prepared 15 years ago at different α-activities by varying the 239 Pu/ 238 Pu isotopic ratio. The resulting α-activities range from 1.9×10 7 to 4.2×10 9 Bq g −1 . These samples have a current, accumulated dose that ranges from 8.8×10 15 to 1.9×10 18 α-decays g −1 . A second suite of polycrystalline zircon samples that were synthesized 16 years ago with 10.0 wt.% Pu was also investigated. The 239 Pu/ 238 Pu isotopic ratio in these samples resulted in α-activities of 2.5×10 8 and 5.6×10 10 Bq g −1 and an accumulated dose of 1.2×10 17 and 2.8×10 19 α-decays g −1 . For both the glass and ceramic waste forms, initial analysis of Extended X-Ray Absorption Fine Structure (EXAFS) and X-Ray Absorption Near Edge Structure (XANES) indicate that the local environment around the actinides exhibit different degrees of disorder as a result of the accumulated α-decay dose.
A flow‐through reaction cell that couples time‐resolved X‐ray diffraction with stable isotope analysis

A non-metallic flow-through reaction cell is described, designed for in situ time-resolved X-ray diffraction coupled with stable isotope analysis. The experimental setup allows the correlation of Cu isotope fractionation with changes in crystal structure during copper sulfide dissolution. This flow-through cell can be applied to many classes of fluid-mineral reactions that involve dissolution or ion exchange.
The influence of second-phase dispersions on shear instability and fracture toughness of ultrahigh strength AISI 4340 steel

The resistance to shear instability and subsequent flow localization in ultrahigh strength (UHS) steels is dependent upon second-phase particle dispersions and the matrix strain hardening. The effect of the interparticle spacing λ to the geometric mean particle radius R ratio on the shear instability strain of UHS AISI 4340 steel is discussed. Experimental results indicate that a linear relationship exists between shear instability strain and this λ/R ratio. Microvoid nucleation softening associated with second-phase particles appears to be the dominant destabilizing event leading to fracture. The effect of the hydrostatic stress is also discussed. Experimental results of mode I and II fracture toughness testing are compared. A high hydrostatic tension field was found to be the cause for the lower mode I critical stress intensity factor (KIc) than mode II (KIIc). The high hydrostatic tensile stress field induced early microvoid nucleation which promoted flow localization leading to fracture. However, both mode I (KIc) and mode II (KIIc) critical stress intensity factors directly relate to the critical particle parameter λ/R12.
Irreflexive and reflexive dimension

There are three equivalent definitions of dimension for partially ordered sets. When generating these three definitions to C-dimension over an arbitrary class of orders C, the three definitions diverge. We compare these three definitions and determine certain requirements under which they are equivalent.
Alteration of membrane permeability to calcium ions during maturation of bovine spermatozoa.

Abstract Bovine spermatozoa, maturing in the caudal epididymis, apparently have a low content of mobilizable Ca2+ (6 ± 1 nmoles Ca 2+ 10 8 cells) in situ, but will accumulate added Ca2+ when simply diluted into isotonic media. It is suggested that the low concentrations of Ca2+ (0.5 ± 0.1 mM) and O2 present in epididymal fluids prevent the accumulatin of Ca2+ by sperm prior to ejaculation. Although the seminal plasma that surrounds ejaculated sperm contains 9 ± 1 mM Ca2+, washed ejaculated sperm also have a low Ca2+ content (7 ± 1 nmoles Ca 2+ 10 8 cells). Moreover, in contrast to epididymal sperm, washed ejaculated sperm are incapable of accumulating Ca2+ supplied exogenously. Evidence is presented that bovine seminal fluids contain a component that is added to the surface membranes of the sperm at ejaculation which prevents or delays the active uptake of Ca2+ by these cells.
Mechanism of Phosphorylation of Protein Kinase B/Akt by a Constitutively Active 3-Phosphoinositide-dependent Protein Kinase-1

Phosphorylation of Thr308 in the activation loop and Ser473 at the carboxyl terminus is essential for protein kinase B (PKB/Akt) activation. However, the biochemical mechanism of the phosphorylation remains to be characterized. Here we show that expression of a constitutively active mutant of mouse 3-phosphoinositide-dependent protein kinase-1 (PDK1A280V) in Chinese hamster ovary cells overexpressing the insulin receptor was sufficient to induce PKB phosphorylation at Thr308 to approximately the same extent as insulin stimulation. Phosphorylation of PKB by PDK1A280Vwas not affected by treatment of cells with inhibitors of phosphatidylinositol 3-kinase or by deletion of the pleckstrin homology (PH) domain of PKB. C2-ceramide, a cell-permeable, indirect inhibitor of PKB phosphorylation, did not inhibit PDK1A280V-catalyzed PKB phosphorylation in cells and had no effect on PDK1 activity in vitro. On the other hand, co-expression of full-length protein kinase C-related kinase-1 (PRK1/PKN) or 2 (PRK2) inhibited PDK1A280V-mediated PKB phosphorylation. Replacing alanine at position 280 with valine or deletion of the PH domain enhanced PDK1 autophosphorylation in vitro. However, deletion of the PH domain of PDK1A280V significantly reduced PDK1A280V-mediated phosphorylation of PKB in cells. In resting cells, PDK1A280V localized in the cytosol and at the plasma membrane. However, PDK1A280V lacking the PH domain localized predominantly in the cytosol. Taken together, our findings suggest that the wild-type PDK1 may not be constitutively active in cells. In addition, activation of PDK1 is sufficient to phosphorylate PKB at Thr308 in the cytosol. Furthermore, the PH domain of PDK1 may play both positive and negative roles in regulating the in vivo function of the enzyme. Finally, unlike the carboxyl-terminal fragment of PRK2, which has been shown to bind PDK1 and allow the enzyme to phosphorylate PKB at both Thr308 and Ser473, full-length PRK2 and its related kinase PRK1/PKN may both play negative roles in PKB-mediated downstream biological events.
The impact of a strategy of image-guided left ventricular lead placement during cardiac resynchronization therapy on health care utilization

Cardiac resynchronization therapy Health care utilization LV lead position Heart failure hospitalization
Analysis of Domain Movement and Dynamics of Norwalk Virus Capsid by Molecular Dynamics (All-Atom and Coarse Grained) Simulations and Normal Mode Analysis

Norwalk virus is the major cause of epidemic gastroenteritis in humans. The capsid of the virus consists of 180 copies of a single protein which has a protruding (P) domain and a shell (S) domain. In this work, the mechanism of domain movements of the protein is investigated by Gaussian network model(GNM) and anisotropic elastic network model(ANM). The dynamics of various residues and C-terminus are examined by Molecular Dynamics Simulations (MD):Coarse-grained and all-atom. Preliminary results are as follows:(i) slow coordinated motions are identified in the hinge regions, (ii) the C-terminus residue interacts with specific residues within P domain only and (iii) normal mode analysis, coarse-grained MD and all-atom simulation generate largely consistent results.
Rationale for Phase III Trials of Thoracic Radiation Therapy Doses in Limited-Stage Small-Cell Lung Cancer

Abstract The optimal integration of thoracic radiation therapy with systemic chemotherapy in the treatment of limitedstage small-cell lung cancer remains to be defined. Although there are many unsettled issues, it has been more than 15 years since the most recent phase III Intergroup study completed accrual. In March 2008, a phase III Intergroup study assessing high-dose thoracic radiation therapy in limited-stage small-cell lung cancer was activated in the United States, and a randomized study in Europe is also investigating a thoracic radiation therapy dose escalation. The rationale for these trials is described herein.
Hydrogen sensing behavior of Pt-coated mesoporous anodic titania

Abstract We report on excellent hydrogen sensing properties of a Pt/TiO 2 system based on mesoporous titania grown by plasma electrolytic oxidation of a Ti metal substrate. The Pt phase is deposited onto the titania surface as an electrically continuous Pt nanomesh layer with an e-beam process. Resistive sensor response between the Pt and Ti terminals of the resultant structure is studied at room temperature for different partial pressures of H 2 gas (0.003–3 Torr) and different source voltages (0.5–2.0 V). A maximum resistance effect, reaching four orders of the magnitude for 3 Torr H 2 in 160 Torr O 2 is obtained at the bias voltage 1.4 V, and a strong effect is detected for only 0.003 Torr, or 20 ppm H 2 concentration. For voltages in the range 1.0–1.4 V, electrical conductance of the sample is about a linear function of the H 2 partial pressure in the gas phase. Influence of the background atmosphere (O 2 , N 2 and vacuum) and the effect of bias reversal were investigated also, leading to a conclusion that the sensing mechanism can be related to ionic transport in the TiO 2 layer.
A Medium Access Control Scheme for Wireless LANs with Constant-Time Contention

In today's wireless networks, stations using the IEEE 802.11 Standard contend for the channel using the Distributed Coordination Function (DCF). Research has shown that DCF's performance degrades especially with the large number of stations. This becomes more concerning due to the increasing proliferation of wireless devices. In this paper, we present a Medium Access Control (MAC) scheme for wireless LANs and compare its performance to DCF and to other efficient schemes. Our scheme, which attempts to resolve the contention in a constant number of slots (or constant time), is called CONTI. The contention resolution happens over a predefined number of slots. In a slot, the stations probabilistically send a jam signal on the channel. The stations listening retire if they hear a jam signal. The others continue to the next slot. Over several slots, we aim to have one station remaining in the contention, which will then transmit its data. We find the optimal parameters of CONTI and present an analysis on its performance. More comprehensive evaluation is presented in the simulation results where we compare CONTI, DCF, and other efficient schemes from the literature. We consider the number of slots used, the collision rate, the throughput, the delay, and the fairness. The highest throughput was achieved by CONTI. Moreover, our results provide measurements from each of the schemes that we consider and provide the insight on each scheme's operation.
Primary Root Growth Regulation: The Role of Auxin and Ethylene Antagonists

We investigated the growth and development of flax roots in the presence of auxin antagonists 4,4,4-trifluoro-3-(indole-3-)-butyric acid (TFIBA), p-chlorophenoxyisobutyric acid (PCIB), and the ethylene inhibitor silver thiosulfate. Of these compounds, silver thiosulfate was most effective in promoting root elongation. All compounds reduced root diameter and root hair development. The effects of TFIBA were reversed by exogenous indole-3-acetic acid (IAA) or 1-aminocyclopropane-1-carboxylic acid (ACC). Because the ethylene and ACC content of roots was reduced by TFIBA and PCIB but increased by silver thiosulfate, we measured the transcription level of five isoforms of ACC synthases (Lu-ACS1-5) and three isoforms of ACC oxidases (Lu-ACO1-3). Lu-ACS1-3 were inhibited by TFIBA and PCIB but promoted by silver thiosulfate and by exogenous IAA. TFIBA inhibited all three ACC oxidase isoforms but PCIB inhibited only Lu-ACO3. Silver thiosulfate and IAA upregulated Lu-ACO1 and Lu-ACO2. Exogenous IAA affected transcription of ACC synthases and ACC oxidases in a concentration-dependent manner. The root promotion by TFIBA and PCIB is related to ethylene, but may also involve auxin interactions.
The Surgeon, Healer With Work at Hand: Presidential Address

On the front cover of this year's program there was a picture of a headdress of an Indian medicine man, that of a shaman of the Tlingit Indians from here in the Pacific Northwest (Fig 1). It is said that he was so highly regarded as a healer that he even was called on to attend to some of the early settlers who fell ill. He was affectionately known as Doctor Pete. (Fig 2). In the painting by Sir Luke Fildes (1844 to 1927), entitled The Doctor (1891, Fig 3), the physician posing for the painting is Dr John McDonald who lived and practiced on the Hebrides Island group off the west coast of Scotland. Each picture depicts an individual trusted by his patients, respected by his peers, honored in his lesser community, and esteemed in his greater society. Neither of them—the shaman with his patient and the physician at
Multi-enzyme logic network architectures for assessing injuries: digital processing of biomarkers

A multi-enzyme biocatalytic cascade processing simultaneously five biomarkers characteristic of traumatic brain injury (TBI) and soft tissue injury (STI) was developed. The system operates as a digital biosensor based on concerted function of 8 Boolean AND logic gates, resulting in the decision about the physiological conditions based on the logic analysis of complex patterns of the biomarkers. The system represents the first example of a multi-step/multi-enzyme biosensor with the built-in logic for the analysis of complex combinations of biochemical inputs. The approach is based on recent advances in enzyme-based biocomputing systems and the present paper demonstrates the potential applicability of biocomputing for developing novel digital biosensor networks.
Nitrate and fecal coliform concentration differences at the soil/bedrock interface in Appalachian silvopasture, pasture, and forest

A major limitation to efficient forage-based livestock production in Appalachia is asynchrony of forage availability and quality with nutritional requirements of the grazer. Producers require dependable plant resources and management practices that improve the seasonal distribution and persistence of high quality herbage, sustainability and environmental integrity of the agricultural landscape. It was hypothesized that inorganic N and fecal coliform concentrations delivered in leachate to the soil/bedrock interface would be lowest in deciduous forest (HF) and highest in pasture (CP) with HF converted to silvopasture (SP) between the two. Piezometers were used to monitor water quality at the soil/bedrock interface under conventional pasture, SP, and hardwood forest. The pasture and SP were rotationally grazed by sheep during the spring to fall grazing season (2004–2008). Geometric mean fecal coliform bacteria concentrations (FC) were greatest in SP (18 FC 100 mL−1) with no difference between CP (7.5 FC 100 mL−1) and HF (5.6 FC 100 mL−1). Mean NO3-N concentration was lowest in SP (2.3 mg L−1) and greatest in CP (4.4 mg L−1) and HF (4.1 mg L−1), which were not significantly different. Mean NH4-N concentrations showed different trends with the lowest mean concentration in CP (0.5 mg L−1) and the greatest in SP (2.5 mg L−1) and HF (2.6 mg L−1), which were not significantly different. SP was shown to be a management option in the study area that reduces nitrate leaching, but should be considered cautiously in near-stream areas and near wells where fecal bacteria pollution can be problematic. This study makes an important contribution to our knowledge about interactions between landscape management and environmental quality of the Appalachian region. A diversity of land and forage management options are needed to maximize forage and livestock productivity while protecting surface and groundwater quality of the region.
Reconfigurable infrared frequency selective surfaces

In this paper, a new reconfigurable frequency selective surface (RFSS) design concept is introduced. A grid of simple metallic patches interconnected by a matrix of switches is proposed as the unit cell of an RFSS. The switches are independently addressable and provide significant transmission and reflection flexibility over a large range of frequencies. This flexibility is exploited by optimizing the switch settings using a genetic algorithm (GA) to produce a desired frequency response. The versatility of the design technique is demonstrated by presenting several examples of genetically optimized RFSSs. The first geometry to be considered is a linearly polarized FSS that can be reconfigured for either single-, dual-, or tri-band operation. An RFSS design is also introduced that can be optimized to have a frequency response that is polarization independent in one state (i.e., for one combination of switch settings) and polarization dependent in another state.
The Social Context of Democratic Authority: A Sympathetic Response to Quantz, Cambron-McCabe and Dantley.

As a former president of a teacher's union and as a political/educational activist, there is no doubt in my mind that I would have supported most of the changes in the education of administrators that the authors of "Preparing School Administrators for Democratic Authority" describe. I have all too many vivid memories of discussions with principals and "the central office" that ultimately were reduced to the infamous accountant's bottom line or to "authority," not to what was ethically justifiable, socially critical, or even educationally wise. In fact, it is not an unimportant fact in my own intellectual and political development that I spent many years of my life as a teacher in a decaying old industrial city largely teaching children of color whose condition of extreme poverty was even then hard to imagine. These conditions have got worse; so bad, in fact, are they that they place under severe threat the very claim that this society is democratic at anything other than the level of rhetoric. Let me begin my comments here with an all too brief assessment of the current situation, since a positive response to Quantz, Cambron-McCabe, and Dantley's arguments is dependent on one's understanding of the social conditions impacting on schools. What is happening in American society that should give us reason for serious concern? There is a crisis in education and the larger society. Seen from below, it is evidenced in the increase in poverty, in the defunding of the educational and social programs that took many years to win and that are still crucially necessary, in the attempts by rightist groups to impose their beliefs upon others, and in the widespread deskilling of jobs as industries engage in capital flight by moving their plants to other nations, thereby destroying whole corn-
Lifting of trajectories of control systems related by smooth mappings

Abstract Given a pair of control systems x ˙ = f ( x , u ) and y ˙ = h ( y , v ) whose state spaces are differentiable manifolds M and N , respectively, we focus on situations where there exists a mapping Φ : M → N that induces some type of correspondence between the trajectories of the systems. An important instance of this situation occurs when f is a complex system (for example, one having many states), h is a subsystem of f (presumably, with fewer states and a simpler structure than f ), and Φ is a mapping from the full state space M to a reduced state space N . Some recent research has concentrated on the concept of Φ -related systems, where it is required that Φ send trajectories of f onto trajectories of h . Here we approach the problem from a different direction and ask under what conditions trajectories of the subsystem h can be lifted to trajectories of the full system f . We provide computable sufficient conditions for the local and global lifting of trajectories from N to M . Connections between the lifting problem and the problem of global ( f , g ) -invariance are also discussed briefly.