cssi/SciSciGPT-SciSciNet huggingface dataset:
Quantitative Analysis of ERK2 Interactions with Substrate Proteins: ROLES FOR KINASE DOCKING DOMAINS AND ACTIVITY IN DETERMINING BINDING AFFINITY

Extracellular signal-regulated kinase-1 and -2 (ERK1/2) proteins regulate a variety of cellular functions, including cell proliferation and differentiation, by interacting with and phosphorylating substrate proteins. Two docking sites, common docking (CD/ED) domain and F-site recruitment site (FRS), on ERK proteins have been identified. Specific interactions with the CD/ED domain and the FRS occur with substrates containing a docking site for ERK and JNK, LXL (DEJL) motif (D-domain) and a docking site for ERK, FXF (DEF) motif (F-site), respectively. However, the relative contributions of the ERK docking sites in mediating substrate interactions that allow efficient phosphate transfer are largely unknown. In these studies, we provide a quantitative analysis of ERK2 interactions with substrates using surface plasmon resonance to measure real time protein-protein interactions. ERK2 interacted with ELK-1 (DEF and DEJL motifs), RSK-1 (DEJL motif), and c-Fos (DEF motif) with K(D) values of 0.25, 0.15, and 0.97 μM, respectively. CD/ED domain mutations inhibited interactions with ELK-1 and RSK-1 by 6-fold but had no effect on interactions with c-Fos. Select mutations in FRS residues differentially inhibited ELK-1 or c-Fos interactions with ERK2 but had little effect on RSK-1 interactions. Mutations in both the ED and FRS docking sites completely inhibited ELK-1 interactions but had no effect on interactions with stathmin, an ERK substrate whose docking site is unknown. The phosphorylation status of ERK2 did not affect interactions with RSK-1 or c-Fos but did inhibit interactions with ELK-1 and stathmin. These studies provide a quantitative evaluation of specific docking domains involved in mediating interactions between ERK2 and protein substrates and define the contributions of these interactions to phosphate transfer.
Energy Efficiency of Adaptive Transmission for MIMO-OFDM Systems over Polarization-Sensitive Channels

The employ an adaptive space-polarization MIMO test bed to investigate the energy efficiency of different adaptive precoded MIMO architectures, including co-polarized MIMO (CP-MIMO), dual-polarized MIMO (DP-MIMO), and space-polarization MIMO (SP-MIMO) architectures. The analysis quantifies the relative energy efficiencies and achievable rates when precoding is used. The performance is investigated over different polarization-sensitive channels and includes the impact of packet erasures. The adaptive precoding analysis relies on accurate and repeatable physical channel realizations from the test bed, which demands sophisticated hardware and test bed calibration procedures. Examples results from the test bed are presented, illustrating the relative energy efficiencies among the different MIMO architectures.
Surface effects related to voltage breakdown in CTR devices

Abstract Aspects of both vacuum breakdown and unipolar arcs of importance to CTR devices are discussed. A design correlation for vacuum breakdown is presented for three regimes related to surface treatment: initial, field-emission, and ultimate. For the initial regime, the breakdown voltage V b and equivalent spacing y are related by V b (volt) ∼48.8 y 1 2 (cm). Extensive surface treatment allows voltages ∼6 × higher, but long-term maintenance of surface conditions is difficult. Unipolar arc formation at the sheath of a plasma-wall interface could lead to erosion rates equivalent to ∼10 sputtered atoms per bombarding ion, several orders of magnitude larger than for normal ion sputtering. Suppression of arcing by area subdivision or by insulating coatings is discussed.
Kinetic Studies of the Electrochemical Treatment of Nitrate and Nitrite Ions on Iridium‐Modified Carbon Fiber Electrodes

Electrochemical reductions of nitrate and nitrite ions in neutral solution were studied using an Ir-deposited carbon fiber electrode. The objective of the study was to set up a process to remove nitrate and nitrite ions from industrial and municipal wastes as well as from the nitrate and nitrite ion enriched water supplies. Since nitrate and nitrite ion reduction kinetics is very slow on plain carbon, the iridium-modified fibers showed a significant reduction of nitrate and nitrite ions. Nitrogen and ammonia were identified as the two major gaseous products of the reduction process. A first-order inhibition kinetics model is proposed and was used to analyze the nitrate and nitrite ion reduction kinetics. The reduction rates of nitrate and nitrite ions were favored at higher cathode potential (cf. -950 mV and -850 mV) in a solution of pH = 7.0 with hydrogen evolution efficiency increasing with cathodic potential. A simple model for the batch re-circulation process was developed for the reduction of nitrate ion at surface-modified fiber electrode. There was a good agreement between the model predictions and experimental results.
The Effects of Sex, Race, and Achievement on Schoolchildren's Friendships

We use panel data on schoolchildren's friendship choices to investigate the effects of sex, race, and academic achievement on the formation of new friendships and on the stability of existing friendships. Cross-sectional analysis of the data reveals commonly expected associations: a child's friendship choices are positively associated with being the same sex and race as the other child and with having a similar achievement level. Panel analysis of the data suggests ways that these cross-sectional associations may arise. Although the stability of existing friendships is significantly affected by the children's characteristics, the formation of new friendships appears to be almost random, except for a positive effect of their being the same sex. Further, the status value of characteristics in the larger society does not seem to influence changes in friendship choices. Characteristics of children appear to affect friendship changes mainly because children tend to favor those like (or similar to) themselves on a characteristic. There is an important exception. Children's being the same race does not significantly influence changes in friendship choices when their achievement is controlled. The effects of race are limited to a tendency of black children to form and maintain friendships more readily than nonblack children.
The temporal correlation of dynamic contrast-enhanced magnetic resonance imaging with tumor angiogenesis in a murine glioblastoma model.

Abstract Objective: Glioblasomta multiforme (GBM) is a WHO grade IV malignant brain tumor with poor prognosis, despite advances in surgical and adjuvant therapy. GBM is characterized by areas of central necrosis and high levels of angiogenesis, during which increased vascular permeability allows for the extravasation of endothelial progenitor cells to support blood vessel and tumor growth. The purpose of this study was to characterize changes in tumor vascular permeability, vascular density and vessel morphology in vivo during angiogenesis. Methods: An orthotropic murine (GL26) glioblastoma model was used in this study. in vivo serial dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in combination with histologic and molecular genetic analyses was performed to correlate in vivo imaging of vascular development. Results: DCE-MRI revealed a significant change in tumor vessel permeability dependent upon tumor progression and size. Time to max signal intensity displayed a stepwise increase betwee...
Digital Imaging, Archiving, and Structured Reporting in Pediatric Echocardiography: Impact on Laboratory Efficiency and Physician Communication

Background Digital structured reporting (DSR) is an emerging technology in medical information management. In November of 2006, the pediatric echocardiography laboratory at Children's Hospital of Wisconsin transitioned from transcription-based reporting of results to DSR. Methods Transthoracic echocardiograms were reviewed for the study duration and time to report completion for October of 2006 (the last month of phone-based transcription) and January of 2007 (the third month of DSR). For both months, the 5 cardiologists responsible for echocardiography reporting were evaluated for report generation time and the 5 sonographers were evaluated for study duration. Data for physicians and sonographers were analyzed individually, as a group between months, between examination types (brief vs comprehensive), and diagnoses (normal vs abnormal findings). Results The time to generate a final report to the electronic medical record/auto-fax to the referring physician for all examination types between months decreased significantly from the transcription month to the DSR month (median 23.8 vs 1.2 hours; P = .001). This decrease was consistent among physicians and occurred despite an increase in monthly echocardiography volume of 12% between the study periods. No difference was noted in report generation times between brief and comprehensive transthoracic echocardiography for transcription ( P = .220) or DSR ( P = .185). Analysis of diagnoses after instituting DSR revealed significantly shorter report generation time for normal examination findings versus abnormal examination findings (0.97 vs 1.5 hours; P = .001). Study duration decreased significantly from the transcription month to the DSR month for all examination types (32 vs 27 minutes; P = .001). For both months, the study duration was longer for abnormal versus normal transthoracic echocardiography findings (transcription: 37 vs 27 minutes; DSR: 32 vs 23 minutes). Conclusions DSR is a superior technology for pediatric echocardiography reporting and an important next step to increase efficiency and customer satisfaction. Although congenital heart disease increases DSR study report time, the value of digitally scripted, database-compatible, complete segmental analysis of the heart and vascular structures with direct transfer of quantitative data from the ultrasound machine to the report without the need for a transcription interface justifies the time expense. DSR should be a goal for all pediatric echocardiography laboratories to decrease consumer wait time, increase laboratory efficiency, and improve compliance with Intersocietal Commission for the Accreditation of Echocardiography Laboratories standards.
Knowledge and attitudes of visitors to patients in contact isolation

In this study, conducted at a tertiary care center, we surveyed visitors to patients in contact isolation to assess their knowledge and attitudes about contact isolation. Although response rates were low, we found that visitors had an overall positive perception and understanding of contact isolation. We think this is likely attributable to the communication and education provided by health care providers to the visitors.
The US freshwater supply shortage: Experiences with desalination as part of the solution

Abstract Parts of the USA are facing impending shortages of freshwater. One proposed solution is the construction of desalination plants to turn seawater into freshwater. Although seawater desalination plants are widely used in the Middle East, especially Saudi Arabia, there are few desalination plants in the USA. In 2003, Tampa Bay Water built the largest desalination plant in North America. Persistent operating problems and escalating costs have caused the utility to re-evaluate its reliance on the seawater desalination plant as part of a long-term regional water supply strategy. In addition, environmental effects of the plant are uncertain. Advances in reverse osmosis technology have significantly reduced desalination costs. However, desalination of seawater is still more expensive than other freshwater supply sources and demand management measures. With time and research, seawater desalination may prove to be a sustainable, cost-effective source of new freshwater supplies, especially if plants are cou...
Angiogenic inhibition in high-grade gliomas: past, present and future

High-grade gliomas, especially glioblastoma (GBM), are among the most aggressive and vascularized tumors. Angiogenesis plays a significant role in tumor growth and survival, and thus offers a target for anticancer treatment. Bevacizumab, a humanized monoclonal antibody against VEGF, was approved by the US FDA as a single agent for the treatment of recurrent glioblastoma. Significant radiographic response and progression-free survival were seen with bevacizumab treatment. However, benefits to overall survival remain undetermined. Other antiangiogenic strategies targeting VEGF, VEGF receptor (VEGFR) and other angiogenic factors have also been examined. Tumor progression after antiangiogenic treatment is inevitable, and effective salvage therapy is yet to be identified. Mechanisms of resistance to antiangiogenic therapy include activation of alternative proangiogenic pathways and increased tumor invasion. Strategies targeting these escape mechanisms are currently being investigated. The use of antiangiogenic...
The effect of deuterium labeling on the width of a ‘metastable peak’

Studies have been made of the energy release during the decomposition of metastable ions in the mass spectra of pyrazine, pyrazine-d4, pyrimidine, pyrimidine-d4, pyridazine and symmtriazine. In all the compounds except pyridazine very small amounts of energy have been measured in some processes. The recorded energy release of 187 μeV for a transition of the symmtriazine molecular ion is the smallest energy release yet recorded. In the case of pyrazine and pyrimidine the energy release in one transition was found to be smaller than in the corresponding transition in the -d4 analogues.
Corporate policies restricting trading by insiders

Abstract This paper examines policies and procedures put in place by corporations to regulate trading in the stock by the firm's own insiders. Over 92% of our sample companies have their own policies restricting trading by insiders, and 78% have explicit blackout periods during which the company prohibits trading by its insiders. Our data indicate that blackout periods successfully suppress trading, both purchases and sales, by insiders, and that the blackout period is associated with a bid–ask spread that's narrower by about two basis points. Consistent with this effect on the spread, allowed insider trades are modestly more profitable than insider trades made during prohibited blackout periods.
Replacement of the axial histidine ligand with imidazole in cytochrome c peroxidase. 2. Effects on heme coordination and function.

The inability of imidazole to complement function in the axial histidine deletion mutant, H175G, of yeast cytochrome c peroxidase has been an intriguing but unresolved issue that impacts our understanding of the role of axial ligands in heme catalysis. Here we report the functional and spectroscopic properties of H175G and of its complexes with imidazole. Combined with the crystal structures for these complexes, the data provide a detailed and consistent account of the modes of Im binding in the H175G cavity and their dependence on buffer and pH. UV−vis, EPR, and resonance Raman spectra reveal multiple coordination states for H175G/Im which can be correlated with the crystal structures to assign the following heme environments: H175G/H2O/H2O, H175G/Imd/phosphatec, H175G/Imd/H2Oc, H175G/Imc/H2Od, and H175G/Imc/OH-c, where H175G/X/Y defines the proximal species as X and the distal species as Y and c and d subscripts refer, where known, to the coordinated and dissociated states, respectively. Resonance Rama...
Vital root retention in humans: A final report

A research protocal for submucosal vital root retention in humans has been developed based on laboratory animal studies. Procedures, patient management, and statistical results have been reported in a series of three articles. Changes in techniques have also been reported, along with explanation of a flowchart for tooth root retention and alveolar ridge preservation. Some ideas for future investigations are presented. Vital root retention in humans appears to be a valid means of retaining residual bony ridge tissues to a greater degree than when patients are rendered totally edentulous.
Going along versus getting it right: The role of self-integrity in political conformity

People often conform to the opinions of ingroup members, even when available evidence suggests that the group is misinformed. Following insights from the social identity approach and self-affirmation theory, it was hypothesized that people conform to salient opinions in an effort to maintain global self-integrity. In a series of experiments examining Americans' approval of President Obama and his policies, approval was consistently swayed by normative information (national polling data) but not by evidentiary information (indicators of national economic health), except under theory-predicted conditions. When participants had satisfied their sense of self-integrity with a self-affirmation exercise (Democrats in Study 1, Republicans in Study 2), or when they had low levels of American identification and thus were less concerned with national norms (Democrats and Republicans in Study 3), they showed the opposite pattern and were swayed by evidence in spite of contradicting normative information. The extent to which people are influenced by norms versus evidence in political judgment is shaped by social identity, one aspect of self-integrity. The results highlight a social psychological means to attenuate and potentially reverse conformity in the face of contradicting evidence, a finding with both practical and theoretical implications.
Mechanism of partial oxidation of methanol over MoO3

The partial oxidation of methanol was carried out over molybdenum oxide at low temperatures, where high-order products (dimethyl ether, dimethoxymethane, and methyl formate) were formed in small amounts. Both the electronic and the geometric states of the catalysts were observed by techniques such as transient experiments, volumetric adsorption, and in situ infrared observation of methoxy group and Mo-O structural bands. Correlation of activity data with data on the surface state makes it possible to suggest a reaction mechanism for the partial oxidation of methanol over molybdenum oxide. The reaction can be represented by a mechanism involving methoxy intermediates chemisorbed on oxygen vacancy sites. Formaldehyde and CO are mainly produced from methoxy on terminal oxygen (Mo{double bond}O) vacancy sites while bridged oxygen (Mo-O-Mo) vacancy sites are responsible for the production of dimethyl ether, dimethoxymethane, and methyl formate. The bond strength of chemisorbed methoxy is greatly affected by the electronic state of the oxygen vacancy. Reduced oxygen vacancy sites weaken the CH bond but strengthen the CO and chemisorption bonds in the methoxy, resulting in the formation of more hydrogen-abstracted products. The decrease in the formation of high-order products (dimethyl ether, dimethoxymethane, and methyl formate) at high reaction temperatures is caused bymore » the decrease in the concentration of bridged oxygen vacancy sites by formation of shear planes in the surface layers.« less
Nanostructured Ni-Co alloys with tailorable grain size and twin density

We present an experimental approach to systematically produce nanostructures with various grain sizes and twin densities in the Ni-Co binary system. Using electrodeposition with various applied current densities and organic additive contents in the deposition bath, we synthesize nanostructured fcc and hcp solid solutions with a range of compositions. Due to the low stacking fault energy (SFE) of these alloys, growth twins are readily formed during deposition, and by adjusting the deposition conditions, a range of twin boundary densities is possible. The resulting nanostructured alloys cannot be described by a single characteristic length scale, but instead must be characterized in terms of (1) a true grain size pertaining to general high-angle grain boundaries and (2) an effective grain size that incorporates twin boundaries. Analysis of Hall-Petch strength scaling for these materials is complicated by their dual length scales, but the hardness trends found in Ni-80Co are found to be roughly in line with those seen in pure nanocrystalline nickel.
W* effect considered harmful [Internet WAP]

Claiming that "wireless is different" WAP 1.1 rewrites almost every Web standard in the book. The commercial demand for WAP has proved sufficient to implement most of its technologies, but it should be adopted very cautiously. The author discusses the component technologies of WAP.
Transurethral Microwave Thermotherapy for Management of Benign Prostatic Hyperplasia: A Single-Institution Experience

Objectives. This is the first and largest single institution retrospective study in the United States to examine the effects of transurethral microwave thermotherapy (TUMT) for the treatment of benign prostatic hyperplasia (BPH). Methods. From September 1996 to June 1997, 78 men with moderate to severe symptomatic BPH were treated with the Prostatron at our institution. Patient age ranged from 52 to 85 years. Prostate volume ranged from 23 to 110 cc, and mean total energy applied during the treatment was 156.17 kJ. Patients were re-evaluated at 3 months and were asked to answer a questionnaire regarding their opinion about the treatment. Results. At 3 months there was a significant decrease in mean symptom score from 19.6 to 11.2 (P <0.0001). Mean peak flow rate increased from 8.5 to 12.8 mL/s (P <0.0001). Mean postvoid residual urine decreased from 56.8 to 22.0 mL (P <0.0001). We did not observe any severe complications. Unlike prior studies, we removed the Foley catheter, and patients performed clean intermittent catheterization (CIC) when necessary. There was no significant differences in subjective and objective parameters between these patients and those who did not need CIC. Patient opinion about the treatment was not affected by CIC. About two thirds (67.2%) of the patients in the study group were satisfied with the results of treatment, and 60.3% would undergo the same procedure again. Conclusions. TUMT of the prostate is an effective, safe, and acceptable form of treatment for patients with BPH. Longer follow-up is needed to examine the durability of TUMT treatment.
Bulk and shear viscosities of a polydisperse hard-sphere fluid

The bulk and shear viscosity expressions for a multicomponent hard-sphere mixture in the Enskog transport theory are generalized to the polydisperse limit. The effect of polydispersity is expressed in terms of correction factors to the monodisperse fluid results. These correction factors have been evaluated for both a log-normal size distribution with the mass-size relation of a power-law form and a log-normal mass distribution with fixed particle size, which is the continuous limit of “isotopes”.
Adenoid cystic carcinoma on the dorsum of the tongue

Adenoid cystic carcinoma is a relatively rare epithelial tumor of the salivary glands accounting for about 5-10% of all salivary gland neoplasms. Approximately, 31% of salivary gland neoplasms affect minor salivary glands particularly the palate. It involves tongue in only 19.8% of cases and even rarely the dorsum of the tongue. We report such a rare case that affected dorsum of the tongue in a 45-year-old-female patient.
Polymer structures and turbulent shear stability of drag reducing solutions

THE phenomenon of frictional drag reduction in the turbulent flow of Newtonian fluids, by the addition of high molecular weight polymers, has been known for some time. Because of the great potential it offers in various technological applications this phenomenon has generated considerable engineering interest. Unfortunately, when a limited volume of polymer solution is continuously exposed to mechanical shearing action, either by repeated use1 or by passing through long pipelines2, drag reduction rapidly declines, indicating a rapid breakdown of the polymer molecules3. This polymer degradation greatly limits the application of drag reducing polymers. When considering the use of high molecular weight polymers in operating systems their shear stability must be considered as equally important as their effectiveness in drag reduction. Polymer degradation effect is likely to be caused by the scission of molecular entanglements or the breaking of individual molecules induced by the shear stresses associated with very high local shear rates4. But previous studies were made mainly with linear polymers such as polyethylene oxide (PEO) and polyacrylamide (PAM), because a linear structure was believed to be most effective5. We have studied the effect of polymer structure on turbulent drag reduction by synthesising drag-reducing agents of different structures6. Here we present the results of an investigation of the degradation behaviour of a highly branched PAM, and compare the results with those observed with ordinary linear polymers.
JNK Regulates Autocrine Expression of TGF-β1

The c-Jun NH2-terminal kinase (JNK) has been implicated in the function of transforming growth factor beta (TGF-beta). To test the role of JNK, we examined the effect of compound disruption of the murine genes that encode the ubiquitously expressed isoforms of JNK (Jnk1 and Jnk2). We report that JNK-deficient fibroblasts isolated from Jnk1-/- Jnk2-/- mice constitutively express TGF-beta1. Complementation studies demonstrate that JNK is a repressor of Tgf-beta1 gene expression. This mechanism of regulation of TGF-beta1 expression by JNK represents an unexpected form of cross-talk between two important signaling pathways. Together, these data demonstrate that the JNK pathway may contribute to the regulation of autocrine TGF-beta1-mediated biological responses in vivo.
Early Field Experiences in Preservice Teacher Education: Research and Student Perspectives

Abstract Recent reform efforts in teacher education involve the inclusion of, or a substantial increase in, early field experiences during teacher preparation. This study examines the role and influence of early field experiences through questionnaire and interview responses by school of education graduates. Questionnaires were mailed to 200 graduates, half of whom participated in an enriched teacher preparatory program requiring additional early field experiences. The qualitative and quantitative data gathered were examined to determine (a) graduates perceptions of early field experiences, (b) graduate perceptions of experience outcomes compared to the stated experience objectives, and (c) differences in perceptions of early field experiences by the two groups (graduates of the regular education program, only, and graduates of the supplemental program). Additionally, (d) the two groups' ratings from the North Carolina Teacher Performance Appraisal Instrument (NCTPAI) were compared. Suggestions are given ...
Phosphofructokinase activity in the preimplantation mouse embryo

Phosphofructokinase activity remains relatively constant during the preimplantation period in the mouse, with a low point at day 4 (approximately 3.0×1−11 moles of substrate converted per embryo per hour).
An extinct genus of Salicaceae based on twigs with attached flowers, fruits, and foliage from the Eocene Green River Formation of Utah and Colorado, USA.

A newly recovered twig with attached leaves and flowers from the Eocene Green River Formation of Utah provides the basis for recognizing a new, extinct genus of Salicaceae sensu lato (s.l.). Pseudosalix handleyi gen. et sp. nov. has alternate lanceolate leaves with pinnate, semicraspedodromous venation and a serrate margin with glandular teeth. The inflorescence is terminal on the twig and is unisexual, composed of flowers organized in a paniculoid cyme, with lateral paraclades of pedicellate flowers. The attached pistillate flowers have four prominent sepals that are valvate in bud, spreading but basally fused at anthesis; the single pistil of each flower is ovoid with three or four longitudinal sutures, indicating development to a capsular fruit. Three or four recurved styles radiate from the apex of the pistil, each with a distal globose stigma. The infructescence, verified by attachment to twigs with the same kind of leaves, bore capsular fruits of three and four valves. Associated but unattached, staminate flowers also have four well-developed, basally connate sepals. They are pedicellate and bear several stamens, each with a short filament and globose anther. The available morphological characters place the fossil species within the Salicaceae s.l. as an immediate sister to the clade containing Populus and Salix. Although the likely outgroup genera (including Itoa, Poliothyrsis, Carrierea, and Idesia) to tribe Saliceae all occur in Asia today and not North America, the occurrence of both Pseudosalix and Populus in the Eocene of Utah raises the possibility of a North American origin for the Saliceae.
Interaction of Aflatoxin and Paratyphoid Infections in Broiler Chickens

There was a significant (P less than 0.05) interaction resulting in increased mortality in chickens fed aflatoxin and infected with Salmonella worthington, S. thompson, S. derby, or S. typhimurium var. copenhagen which cause paratyphoid. There was no interaction on body weight or spleen weight; however, there wan an interaction with all four Salmonella species resulting in enlarged livers from which Salmonella could be isolated with increased frequency. Aflatoxin caused a decrease in total serum proteins but a dramatic increase in anti-Salmonella agglutinins in infected birds. These results suggest that aflatoxin impairs some component of the immune system other than that forming humoral antibodies and perhaps other than the reticuloendothelial system which have been reported previously to be impaired during aflatoxicosis in the chicken.
Effect of crosslinking on the friction and wear behavior of soybean oil-based polymeric materials

In this study, the friction and wear behavior of soybean oil-based polymers prepared by cationic polymerization of low saturated soybean oil (LSS) with divinyl benzene and polystyrene are evaluated as a function of crosslink density. Tribological measurements were performed on samples of three crosslink densities (10%, 15% and 20% of crosslinking agent concentration by weight) using a ball-on-flat reciprocating microtribometer with normal loads ranging from 0 to 800 mN. Friction and wear behavior during dry sliding was evaluated using a spherical (1.2 mm radius) silicon nitride probe as well as a conical (100 μm radius, 90° cone angle) diamond probe. Friction behavior was evaluated from single strokes at ramped normal loads, whereas wear experiments were evaluated from 10 to 500 reciprocating cycles at fixed normal loads. All samples showed comparable coefficients of friction. In general a higher crosslinking density resulted in lower adhesive wear. Increased abrasive wear was observed for the lowest and highest crosslinking densities. Atomic force microscopy and scanning electron microscopy of wear tracks were used to elucidate deformation mechanisms in the various samples. These results provide some insight into the friction and wear behavior of soybean oil-based polymers.
Coordinated control of Distributed Generation

This paper presents an approach to coordinate Distributed Generation (DG) such that quantities in an unbalanced distribution system are balanced and power factor corrected. Models for the DG and three-phase distribution network are combined to form a set of Differential Algebraic Equations (DAE) that represent the behavior of the distribution system. Two state-feedback controllers with reference inputs are presented for coordinated control of DG. Both are designed via linearization of the DAE model. The first uses an additional matrix selected so that the outputs match the reference values in steady-state while the second uses an internal model design with integral to drive the outputs to the reference values. The approach is demonstrated on models of 5-bus and 10-bus test systems with inverter-connected DG. The control objective for the 5-bus test system is to balance active line powers across the three phases as supplied from the transmission system. The control objective for the 10-bus system is to correct power factor on each phase as supplied from the transmission system. Robustness of the internal model controller is investigated for uncertainties (up to 25%) in line parameters and unknown step changes (up to 25%) in loads, and results show that control objectives are achieved in the presence of these uncertainties.
Superluminal Signaling and Relativity

Special relativity is said to prohibit faster-than-light (superluminal) signaling, yet controversy regularly arises as to whether this or that physical phenomenon violates the prohibition. I argue that the controversy is a result of a lack of clarity as to what it means to ‘signal’, and I propose a criterion. I show that according to this criterion, superluminal signaling is not prohibited by special relativity.
WHAT LEADERS NEED TO KNOW: A REVIEW OF SOCIAL AND CONTEXTUAL FACTORS THAT CAN FOSTER OR HINDER CREATIVITY

This article provides a current review of research examining contextual factors that can either foster or hinder employee creativity at the individual, job, group, and organizational level. Specifically, we examine the role of leadership and the use of different human resource practices for developing a work context that is supportive of creativity. Finally, based on our review, we discuss practical implications for managers, propose areas that need further research attention, and highlight possible new directions for future research.
Stereoselective high-performance liquid chromatographic assay for pirmenol enantiomers in dog plasma.

Pirmenol enantiomers in dog plasma were quantified using a stereospecific high-performance liquid chromatographic method with ultraviolet detection at 262 nm. Racemic pirmenol and internal standard, (+)-propranolol, were isolated from dog plasma by a three-step extraction procedure using toluene, 0.1 M hydrochloric acid and hexane, respectively. A chiral analytical column (Chiralcel OJ) was used with a mobile phase consisting of hexane—isopropanol—diethylamine (98.9:1.0:0.1). Linear calibration curves were obtained in the concentration range 0.0200–5.00 μg/ml for each enantiomer. Precision of the method, expressed as coefficient of variation for nine quality control samples, was 7.1% for (+)-pirmenol and 6.4% for (−)-pirmenol. Bias was ±2.2% for (+)-pirmenol and ±1.5% for (−)-pirmenol in quality control samples.
Sexual behavior in brown capuchins ( Cebus apella )

We observed sexual behavior patterns in two captive groups of Cebus apella.We obtained data on intersexual solicitations and intersexual competition. The length of proceptivity cycles by females averaged 18.8 ± 1.2 days; this corresponds with published reports of physiological measures of ovulatory cycles. Females initiated sexual interactions with males significantly more than males initiated interactions with females, and female solicitations increased in frequency over the duration of displayed periods of proceptivity. In contrast, male solicitations of females were infrequent and did not change significantly throughout female proceptive phases. Each female solicited the same male throughout a given proceptive phase. We observed no evidence of male-male or female-female competition. Males seem to respond to female sexual behavior directed toward them, rather than initiating sexual interactions themselves. Even so, male sexual interactions with females followed only a small proportion of solicitations.
A scheme for multisource interior tomography

Currently, x-ray computed tomography (CT) requires source scanning so that projections can be collected from various orientations for image reconstruction. Limited by the scanning time, the temporal resolution of CT is often inadequate when rapid dynamics is involved in an object to be reconstructed. To meet this challenge, here the authors propose a scheme of multisource interior tomography for ultrafast imaging that reconstructs a relatively small region of interest (ROI). Specifically, such a ROI is irradiated in parallel with narrow x-ray beams defined by many source-detector pairs for data acquisition. This ROI can be then reconstructed using the interior tomography approach. To demonstrate the merits of this approach, the authors report interior reconstruction from in vivo lung CT data at a much reduced radiation dose, which is roughly proportional to the ROI size. The results suggest a scheme for ultrafast tomography (such as with a limited number of sources and in a scanning mode) to shorten data acquisition time and to suppress motion blurring.
Diagnostic ascertainment of suspicious pancreatic mass: a threshold analysis.

Background & Aims It is frequently difficult to differentiate between a benign and malignant pancreatic mass. The aim of this study was to assess the parameters that affect the decision to perform surgery on a suspicious pancreatic head lesion. Methods A cost-benefit analysis, using decision tree and threshold analysis, accumulates costs and quality-adjusted life years in patients undergoing pancreaticoduodenectomy or expectant management. The threshold value is defined as the diagnostic probability for pancreatic cancer when the cost-benefit relationships of pancreaticoduodenectomy or expectant management are equal. Results For a localized pancreatic head lesion, the threshold probability of cancer is 43%. Any higher probability of pancreatic cancer makes pancreaticoduodenectomy the preferred treatment option. Within a range of $20,000 to $80,000 spent on surgery, the threshold in favor of Whipple procedure remains relatively low at 40% to 65%. A reduced quality of life after surgery weighs against surgery and raises its threshold. Varying quality of life between 100% and 80% changes the threshold between 31% and 67%. The threshold also is increased in younger patients because of the potentially more dire consequences of unnecessary surgery in instances of long life expectancy. Conclusions Even if diagnostic certainty cannot be achieved, it frequently is beneficial to perform surgery despite the risk of subjecting the occasional patient with benign pancreatic head lesion to an unnecessary pancreaticoduodenectomy.
Renal Remodeling Post Myocardial Infarction: The Modulating Actions of Aging

Obesity affects cardiac extracellular matrix (ECM) composition leading to myocardial fibrosis and ultimately diastolic dysfunction. Despite the suggested role of adipokine leptin in obesity-induced myocardial fibrosis, the exact pathophysiologic mechanisms remain unclear. T helper lymphocytes have been shown to play a fundamental regulatory role in cardiac ECM remodeling. As leptin directly regulates T cells responses, we sought to examine the role of leptin in promoting profibrogenic responses in the heart, substantiating the role of leptin-modulated T-helper cells. Female C57BL/6 (WT) and T cell-deficient Rage/e mice were treated with leptin or PBS at 0.3 mg/g/day sc for 4 wk. Leptin-treated WT mice demonstrated an impairment of left ventricular diastolic performance (fig 1) with reduced end-diastolic volume and increased end-diastolic pressure. There was a 19.1% decrease in ventricular filling rate and a 26.3% increase in the slope of the end-diastolic P-V relationship (s) in leptin-treated WT mice compared with respective controls. We also observed a significant decrease in gelatinolytic activity of myocardial matrix metalloproteinase (MMP)-2, suggesting that ECM degradation was diminished. In addition there was an increase in gene and protein expression, and enzymatic activity of lysyl oxidase (LOX), which mediates cross-linking of collagen. These changes in ECM-modifying enzymes coincided with marked increase in myocardial total and cross-linked collagen. Leptin treatment in Rage/e mice resulted in a significant increase in end-diastolic pressure, compared with respective controls. Other parameters showed similar trends as of leptin-treated WT mice, though on a non-significant smaller scale (fig 1). Suppression of MMP-2 and induction of LOX were minimal in Rage/e mice compared with WT counterparts. Correspondingly fibrillar collagen formation and diastolic dysfunction were less prominent in Rage/emice. Our Results suggest a potential role of T lymphocytes in leptin-induced myocardial stiffness and diastolic dysfunction through modulation of ECM-modifying enzymes, mainly MMP-2 and LOX. This study was supported by AHA post-doctoral training to SZ [Figure 1].
Laparoscopic Management of Rectal Prolapse

Rectal prolapse can be a disabling condition for those affected. Treatment has historically been by transanal or abdominal approaches, with transanal approaches tending to have lower morbidity, and abdominal approaches having lower recurrence rates. With the advent of laparoscopy, many of the numerous described abdominal operations have been reported with a minimally invasive approach. Although few randomized data exist, laparoscopic operations appear to provide equal rectal fixation to open surgery, with less morbidity. Coexistent symtoms such as fecal incontinence and constipation must be evaluated before surgery, so that the operation can be tailored to the needs of the individual patient. Patients with severe constipation are often offered a concomitant sigmoid resection, although this does increase the potential for complications. Patients with incontinence, diarrhea, or otherwise normal function can be offered a rectopexy without resection.
Modification of the (Na+ + K+)-dependent ATPase by acetic anhydride and trinitrobenzene sulfonate: specific changes in enzymatic properties.

Abstract Acetic anhydride irreversibly inactivated (Na + + K + )-dependent ATPase preparations from brain, kidney, and eel electroplax. The extent of inactivation was dose dependent, and varied also with the pH of the medium, inactivation decreasing with pH in the range 8.4 to 6.7. Including KCl ( k 0.5 ca. 0.6 m m ) or ATP ( K 0.5 ca. 1 μ m ) in the medium protected against inactivation, whereas MgCl 2 ( k 0.5 ca. 1 m m ) increased inactivation. K + -Dependent phosphatase activity of the enzyme was lost in parallel with (Na + K)-ATPase activity, but Na + -dependent phosphorylation of the enzyme and Na + -dependent ATPase activity were relatively resistant to inactivation. Extraction of the membrane lipids of treated enzyme preparations and replacement with exogenous lipid dispersions did not reverse the inactivation; on the other hand, the catalytic peptide of the enzyme was labeled after incubation with radioactive acetic anhydride. For the enzymatic activity remaining after treatment with acetic anhydride several kinetic properties were also modified. For the K-phosphatase reaction the k 0.5 for K + -activation was greatly increased, whereas for the (Na + K)-ATPase reaction the k 0.5 for neither K + nor Na + was increased, although the apparent k m for ATP was decreased. These observations are interpreted in terms of a decreased apparent affinity for K + at the moderate-affinity α sites of the enzyme, sites involved in (i) activating the K-phosphatase but not the (Na + K)-ATPase reactions and (ii) influencing the k m for ATP. Effects of trinitrobenzene sulfonate (TNBS) on the enzyme preparations were similar: Both KCl and ATP reduced the extent of irreversible inactivation; the pH dependence indicated a p K a for the reactive enzyme groups of 7.5–8; and TNBS affected K + -activation analogously. Moreover, inactivation by acetic anhydride and TNBS followed the pattern of mutually exclusive inhibitors, and prior treatment with TNBS reduced labeling of the enzyme by radioactive acetic anhydride. By contrast, partial inactivation by pyridoxal phosphate or N -ethylmaleimide did not result in a similarly modified enzyme. The effects of acetic anhydride and TNBS appear to be mediated (at least in part) through amino groups not accessible to or reactive with the other reagents: groups which influence the moderate-affinity α sites and which are protected by the presence of K + at these sites.
Relative roles of doxycycline and cation chelation in endothelial glycan shedding and adhesion of leukocytes

Leukocyte [white blood cell (WBC)] adhesion and shedding of glycans from the endothelium [endothelial cells (ECs)] in response to the chemoattractant f-Met-Leu-Phe (fMLP) has been shown to be attenuated by topical inhibition of matrix metalloproteases (MMPs) with doxycycline (Doxy). Since Doxy also chelates divalent cations, these responses were studied to elucidate the relative roles of cation chelation and MMP inhibition. WBC-EC adhesion, WBC rolling flux, and WBC rolling velocity were studied in postcapillary venules in the rat mesentery during superfusion with the cation chelator EDTA or Doxy. Shedding and accumulation of glycans on ECs, with and without fMLP, were quantified by the surface concentration of lectin (BS-1)-coated fluorescently labeled microspheres (FLMs) during constant circulating concentration. Without fMLP, low concentrations of EDTA (1–3 mM) increased FLM-EC sequestration due to disruption of the permeability barrier with prolonged exposure. In contrast, with 0.5 μM Doxy alone, FLM adhesion remained constant (i.e., no change in glycan content) on ECs, and WBC adhesion increased with prolonged superfusion. Without fMLP, EDTA did not affect firm WBC-EC adhesion but reduced WBC rolling flux in a dose-dependent manner. With fMLP, EDTA did not inhibit WBC adhesion, whereas Doxy did during the first 20 min of superfusion. Thus, the inhibition by Doxy of glycan (FLM) shedding and WBC adhesion in response to fMLP results from MMP inhibition, in contrast to cation chelation. With either Doxy or the MMP inhibitor GM-6001, WBC rolling velocity decreased by 50%, as in the case with fMLP, suggesting that MMP inhibition reduces sheddase activity, which increases the adhesiveness of rolling WBCs. These events increase the effective leukocrit on the venular wall and increase firm WBC-EC adhesion. Thus, MMP inhibitors have both a proadhesion effect by reducing sheddase activity while exerting an antiadhesion effect by inhibiting glycocalyx shedding and subsequent exposure of adhesion molecules on the EC surface.
Mild myocardial stunning affects platelet aggregation and certain hemostatic factors in swine.

Myocardial stunning is characterized by transient contractile dysfunction occurring subsequent to an episode of ischemia followed by reperfusion. Platelet activation and he mostatic abnormalities have been described in patients with unstable angina and acute myocardial infarction, however, their role in the pathogenesis of myocardial stunning is unknown. The purpose of this study was to determine if platelet aggre gation and certain hemostatic factors change during myocardial stunning following brief coronary arterial occlusion. Nine Yorkshire swine underwent left anterior descending coronary artery occlusion for 8 minutes followed by 90 minutes of reper fusion. Blood samples were obtained at baseline, at 4 and 8 minutes of occlusion, and at 60 and 90 minutes of reperfusion. Platelet aggregability and concentrations of antithrombin III, protein C, protein S, fibronectin, endothelin 1, and the stable metabolites of thromboxane (TxB2) and prostacyclin (6-keto- PGF 1a) were measured in systemic circulation. ...