cssi/SciSciGPT-SciSciNet huggingface dataset:
A finitely extensible network strand model with nonlinear backbone forces and entanglement kinetics

In an earlier paper, a nonaffine network model of polymer melts was presented in which the rotation caused by shearing as well as the extension of the test strand are hindered by interactions with the network itself. In that work, it was shown that such a strand motion leads to qualitatively correct steady shear and elongational material properties, even though the strand disentanglement rate was constant and the strand force law was linear. These simplifications were accepted in order to emphasize the effects of the strand motion on material properties. In this paper, however, we show that these idealizations cause the model to fail in the start-up of shearing flow because no overshoot is seen in the shear stress growth function. To address this failure, the finitely extensible nonlinear elastic (FENE) network model is introduced in which the FENE force law replaces the Hookean force law used in the earlier finitely extensible network strand (FENS) model. Also, a nonlinear expression for the kinetics of strand disentanglement replaces the assumption of a constant rate of disentanglement. Material properties for the FENE network model are generated by stochastic simulation. The simulation results show that these modifications produce overshoot in the shear stress growth function and result in a more consistent description of finite network strand extensibility.
Spreading of transcriptional repressor SIR3 from telomeric heterochromatin

Telomeric genes and the HM loci in saccharomyces cerevisiae are transcriptionally repressed and adopt a heterochromatin-like structure. The trans-acting factors RAP1, SIR3 and SIR4 are required for telomeric and HM silencing, and are thought to be chromosomal, but how they contribute to histone-dependent repression of adjacent chromatin is unclear. SIR3 suppresses silencing defects in histones, is limiting for silencing adjacent to telomeres, and interacts with the H3 and H4 amino termini in vitro. Here we show that SIR3 co-immunoprecipitates SIR4, RAP1 and histones from cellular extracts, suggesting the presence of large chromatin-associated protein complexes. Crosslinking experiments show that SIR3 is present at HMRa, HMLalpha and telomeres in vivo, and that is spreads from telomeric regions into adjacent chromatin when overexpressed. Thus SIR3 is a structural component of yeast heterochromatin, repressing adjacent genes as it spreads along the chromosome.
How To Stop the Rapists? A Question of Strategy in Two Rape Crisis Centers

Using a comparative case study analysis of two rape crisis centers, this paper addresses the question of how social movement organizations come to define their strategies of action. Through the analysis of interviews of early members of the two rape crisis centers, significant similarities between organization members' social positions, goals, and the political ideologies of the two groups were determined. Yet, each organization chose a different course of action. The macropolitical climate, the local political and social context, the organizational structure, and the personal connections between the movement participants, which together determine the parameters of social movement organizations' actions, help to explain differences in the strategies pursued.
Cytochemical localization of adenylate cyclase and 3',5'-nucleotide phosphodiesterase in Dictyostelium.

Abstract Cytochemical localizations of adenylate cyclase and 3′,5′-nucleotide phosphodiesterase were performed on aggregating Dictytostelium discoideum myxamoebae. The adenylate cyclase reaction product was localized on the inner surface of the plasma membrane. The phosphodiesterase reaction product was localized on the outer surface of the plasma membrane. Differences in enzyme activity were noted according to the state of cell (isolated or aggregated) and according to the cell position in larger aggregates. Heavy precipitation indicative of adenylate cyclase activity was not observed in isolated amoebae, but was often observed in streams and in some cells of aggregates. The precipitation indicative of phosphodiesterase activity could be found in isolated amoebae and in peripheral cells of aggregates.
Feeding Problems in Infants and Children.

This article focuses on factors related to decreased food intake of infants and children, but does not address anorexia or bulimia nervosa. The nature of feeding problems may be behavioral, organic, or a mixture of both. Behavioral problems that affect intake have their roots in 1) parental or cultural expectations for food intake and body habit, 2) parental anxiety about weight gain in a vulnerable child or insecurity about parental skills, 3) power struggles between parent and child that manifest in eating habits, 4) conditions that may have enhanced the gag reflex, such as prolonged orotracheal intubation or a nasogastric tube, 5) failure to establish links between hunger, food intake, and satiety in infants who had not been fed orally for a relatively prolonged period of time at a critical age, and 6) anxiety or depression. Organic causes that lead to decreased food intake include swallowing problems (neurologic or conditioned hypersensitive gag, structural anomalies of the oropharynx, dyscoordinated swallow, painful swallow [eg, esophagitis], and obstructed swallow [eg, stricture, retained foreign body, achalasia]), respiratory distress, excessive fatigability (heart failure, respiratory failure), and lack of appetite (many chronic systemic illnesses). At particular risk for feeding problems are infants of premature birth, children with craniofacial anomalies, those with certain genetic syndromes, and those with neurologic involvement. An evaluation by specialists is recommended for children with obvious behavioral problems but for whom the usual recommendations have failed and for those in whom symptoms cannot be explained solely by behavioral issues or in whom organic causes are suspected. The evaluation preferably should be performed by a team specialized in pediatric feeding disorders or otherwise by an occupational therapist or speech pathologist with expertise in the area of feeding.
On the Control of Human-Robot Bi-Manual Manipulation

As robots begin to permeate the everyday human workspace to collaborate in innumerable and varied tasks, the robotic structure must adhere and replicate human-like gestures for effective interaction. Whether rehabilitation or augmentation, upper arm human-robot interaction is some of the most prevalent and investigated forms of collaboration. However, currently robotic control schemes fail to capture the true intricacies of anthropomorphic motion and intent during simple bi-manual manipulation tasks. This paper focuses on the introduction of bio-inspired control schemes for robot manipulators that coordinate with humans during dual arm object manipulation. Using experimental data captured from human subjects performing a variety of every-day bi-manual life tasks, we propose a bio-inspired controller for a robot arm, that is able to learn human inter- and intra-arm coordination during those tasks. Using dimensionality reduction techniques to make comprehensible the linear correlations of both arms in joint space we fit and utilize potential fields that attract the robot to human-like configurations. This method is then tested using real experimental data across multiple bi-manual tasks with a comparison made between the bio-inspired and traditional inverse kinematic controllers. Using a robotic kinematic chain identical to the human arm, models are evaluated for anthropomorphic configurations.
Simulation optimization in manufacturing analysis: incorporating fuzzy logic admission control in simulation models

Admission Control is of great interest in computer, communication and production network applications. As systems become more complex or need to make decision based on multiple objectives or require to satisfy several constraints, Fuzzy Logic Control (FLC) is a natural tool to handle admission problems. This paper discusses the framework of a tool developed for easily integrating fuzzy logic admission control into Arena simulation models. The tool is implemented as a "drop-in" model block that performs admission control. The block can be configured to perform simple or priority-based admission, as well as multiple queue selection. The FLC "rules" are set through a design-time user interface and stored in an MS Access database. Because multiple FLC blocks may be included in a model, almost any possible admission scenario (multiple entry points, parallel lines, etc) may be modeled. A case study is used to demonstrate the developed framework.
Limits on the CP-even Higgs-boson masses in the minimal supersymmetric model.

We calculate corrections to the masses of the two CP-even Higgs bosons in the minimal supersymmetric model. We find an upper bound for the mass of the lighter Higgs scalar, and a lower bound for the mass of the heavier Higgs scalar. In our analysis we consider all possible variations of superparticle masses between 0.1 and 1 TeV. By requiring the light Higgs boson to be greater than the current experimental bound we rule out a region of the tan\ensuremath{\beta}--top-mass parameter space, where tan \ensuremath{\beta} is the ratio of vacuum expectation values of the two Higgs fields. We make our formalism explicit to elucidate the treatment of mass thresholds.
Commentary on Sander M. Abend's "Freud, transference, and therapeutic action".

(2009). Commentary on Sander M. Abend’s “Freud, Transference, and Therapeutic Action”. The Psychoanalytic Quarterly: Vol. 78, No. 3, pp. 925-935.
Bayesian estimation of cost-effectiveness from censored data

We describe a Bayesian methodology for estimating the cost-effectiveness of a new treatment compared to a standard in a clinical trial, when censoring of survival, the effectiveness variable, induces censoring of total cost. The statistical model assumes that survival follows a Weibull distribution and that total health care cost follows a gamma distribution whose mean has a linear regression on survival time. We summarize the posterior distributions of key parameters by importance sampling. We illustrate the method with an analysis of data from a randomized clinical trial of a treatment for cardiovascular disease.
Management of Chiari I malformation in children: effectiveness of intra-operative ultrasound for tailoring foramen magnum decompression

Patients with Chiari I malformation (CM-1) commonly undergo foramen magnum decompression (FMD). However, there is no consensus on how this should be achieved. An approach would be to rationalize surgical steps based on pre-operative imaging and intra-operative findings. The aim of this study is to assess the usefulness of intra-operative ultrasound scanning (IOUS) in tailoring foramen magnum decompression in children with CM-1 and whether the use of IOUS is effective in reducing the risk of complications without increasing the need for re-operation. We performed a retrospective study. IOUS was utilized during FMD: a subjective assessment was made on whether there was adequate cerebellar tonsillar and/or CSF pulsation following suboccipital craniectomy. If there was adequate pulsation, the dura was not opened. Additional data were collected including age and gender of patients, presence of pre-operative syringomyelia, intra-operative ultrasound findings, length of follow-up, complications and radiological and clinical outcome. The statistical analysis was performed with XLStat®(Addinsoft SARL™, France). Nineteen patients underwent FMD from June 2011 to December 2012. The mean age was 10.5 years; there were nine females and ten males. Eleven patients had syringomyelia at diagnosis. Based on IOUS, eight patients underwent dural decompression and 11 patients bony decompression only. One patient had a post-operative pseudomeningocoele and two patients required re-operation. There was no significant statistical difference between the two groups regarding post-operative improvement in the syrinx. We found that tailoring FMD for patients with CM-1 using intra-operative findings using ultrasound scan was useful in avoiding unnecessary manoeuvres, while not compromising on the outcome.
Synthesis and in vitro biological evaluation of carbon-11-labeled quinoline derivatives as new candidate PET radioligands for cannabinoid CB2 receptor imaging

Abstract Cannabinoids have been recently proposed as a new family of potential antitumor agents, and cannabinoid receptor 2 (CB2) is believed to be over-expressed in tumor cells. This study was designed to develop new radioligands for imaging of CB2 receptor in cancer using biomedical imaging technique positron emission tomography (PET). Carbon-11-labeled 2-oxoquinoline and 2-chloroquinoline derivatives, [11C]6a–d and [11C]9a–d, were prepared by O-[11C]methylation of their corresponding precursors using [11C]CH3OTf under basic conditions and isolated by a simplified solid-phase extraction (SPE) method in 40–50% radiochemical yields based on [11C]CO2 and decay corrected to end of bombardment (EOB). The overall synthesis time from EOB was 15–20 min, the radiochemical purity was >99%, and the specific activity at end of synthesis (EOS) was 111–185 GBq/μmol. Radioligand binding assays indicated compounds 6f, 6b, and 9f display potent in vitro binding affinities with nanomolar Ki values and at least 100–2000-fold selectivity for CB2.
Dual 1,25-dihydroxyvitamin D3 signal response pathways in osteoblasts: Cross-talk between genomic and membrane-initiated pathways

Osteoblasts are key regulatory cells in the control of systemic calcium ion (Ca2+) homeostasis. They, along with cells in the kidney and intestine, function as an integral part of the vitamin D endocrine system. The hormonally active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25[OH]2D3), interacts with osteoblasts at several levels to modulate their phenotype and function. The interactions involve distinct receptor systems that operate on unique time scales. Rapid nongenomic actions (milliseconds to minutes), mediated through membrane receptor systems, do not require protein synthesis and include activation of voltage-sensitive Ca2+ channels, induction of phospholipid and sphingolipid turnover, elevation of intracellular Ca2+ concentrations, priming of parathyroid hormone (PTH)-sensitive ion channels, and activation of second messenger systems. In the longer term (many hours to days), interactions mediated through binding of 1,25(OH)2D3 to nuclear receptors, present in mature osteoblasts, modulate transcription of target genes. Target genes for 1,25(OH)2D3 including those encoding for the bone matrix proteins osteopontin (OPN) and osteocalcin (OCN), possess vitamin D response elements (VDRE) upstream of the transcriptional start site. In addition, it is now clear that a number of intermediate effects (1 to 3 hours) also occur. These effects require longer times than the aforementioned rapid effects, but precede the long-term consequences of activation of nuclear receptors. These include alterations in the phosphorylation state of various proteins secreted by osteoblasts, including OPN, attributable to activation/inactivation of various intracellular protein kinases and phosphatases. Intermediate effects are likely to involve both membrane-initiated rapid actions and transcriptional effects on early genes that do not require the nuclear receptor for 1,25(OH)2D3. These intermediate effects, therefore, represent ideal targets for the study of the interaction or "cross-talk" between rapid membrane-initiated, nongenomic effects and nuclear receptor-mediated, genomic effects of 1,25(OH)2D3 on osteoblasts. Intermediate effects also invite the study of rapid, non-nuclear receptor-mediated genomic effects of 1,25(OH)2D3 on osteoblasts. Complete understanding of the mechanisms by which 1,25(OH)2D3 exerts its pleiotropic effects on osteoblasts and other target cells, contributing to control of Ca2+ homeostasis, requires integration of the concepts learned from studies of both rapid and long-term pathways.
Person and Community in the Culture of Entertainment

Entertainment is so pervasive and influential in contemporary society that it is fair to say we live in an entertainment culture. What are the political, ethical, and spiritual implications of such a cultural environment? Building on the analysis offered in the author’s recent book Caught in Play: How Entertainment Works on You (Stromberg, 2009), this essay argues that entertainment is not susceptible to global moral evaluation, it is not “good” or “bad.” Rather, entertainment is a cultural system through which commitment to certain values is generated. This process, and these values, need to be brought into the light of day and assessed in open and critical discussion.
What really separates casuistry from principlism in biomedical ethics

Since the publication of the first edition of Tom Beauchamp and James Childress's Principles of Biomedical Ethics there has been much debate about what a proper method in medical ethics should look like. The main rival for Beauchamp and Childress's account, principlism, has consistently been casuistry, an account that recommends argument by analogy from paradigm cases. Admirably, Beauchamp and Childress have modified their own view in successive editions of Principles of Biomedical Ethics in order to address the concerns proponents of casuistry and others have had about principlism. Given these adjustments to their view, some have claimed that principlism and casuistry no longer count as distinct methods. Even so, many still consider these two conceptions of bioethical methodologies as rivals. Both accounts of the relationship between casuistry and principlism are wrong. These two conceptions of methodology in biomedical ethics are significantly different, but the differences are not the ones pointed out by those who still claim that they are distinct positions. In this article, I explain where the real similarities and differences lie between these two views.
Postmortem mitotic activity of spermatogonia and spermatocytes in the albino rat

Abstract 1. 1. In the rat spermatogonial mitoses can be found in all phases, and in normal or slightly above normal numbers for 8 hours after death of the animal. Prophases disappear after this time. Sixteen hours after death no normal spermatogonial mitoses are seen. The type A spermatogonia show normal mitotic figures for a longer time than the type B cells. 2. 2. Mitoses of the primary spermatocytes are found in normal numbers up to 16 hours postmortem. At this time only a few prophases are present. 3. 3. Secondary spermatocytes ordinarily do not enter prophase after the second hour postmortem. 4. 4. It is concluded that spermatogonia and primary spermatocytes can survive and show mitotic activity for many hours after death under definitely anaerobic conditions. They may, therefore, be added to the list of cells known to survive under conditions of relative or absolute oxygen deprivation; i.e. certain protozoa, the cells of certain invertebrates, certain embryonic cells and certain malignant tumor cells.
Chemical, Microbiological and Sensory Properties of Plain Nonfat Yogurt

Chemical and microbiological properties of plain nonfat yogurt were determined after 2, 6 and 12 days refrigerated storage. Sensory properties were determined after 6 days storage. Viable culture bacteria concentrations ranged from 140 to 8,000 × 106/g and ratios of lactobacillus to streptococcus ranged from 0.18 to 15.4. Chemical criteria used to characterize products included: pH, titratable acidity, lactic and four other organic acids and lactose by HPLC, and 23 major volatile organic compounds by dynamic headspace analysis. Lactic acid concentrations ranged from 7.5 to 9.9 mg/g. Major flavor volatiles in all yogurts included: acetaldehyde, heptane, acetone, diacetyl, and benzothiazole. Untrained sensory panels showed differences for flavor, aroma and acceptability.
Closure vs. structural holes: how social network information and culture affect choice of collaborators

Collaboration is important to successful organizations and how coworkers are selected is crucial to the dynamics of effective collaborations. In this study we explore how people use social network information, which is increasingly accessible on enterprise systems in organizations, to choose people with whom to collaborate. We conducted a scenario-based study of 459 respondents in a global high-tech company. Our data indicate cultural differences in how social network information was valued when choosing a collaborator. The Chinese, consistent with the cultural value of Guanxi, more closely followed a closure model, whereas Americans favored neither a closure nor a structural holes model. These results provide new insights into how needs for social network information may vary between cultures and how social networking sites might support workers in choosing collaborators from within and across national cultures.
Administrator performance evaluation: A comparison of two measures in the management profile

The Management Profile is an appraisal measure that examines the actual job performance of a manager to ascertain relative strength in six management functions and three leadership roles. The management functions examined are administration, technical competence, influence/control, persuasion, training/development, aad forecasting/planning. The leadership roles examined are: evaluator, director, and motivator. This study examined relationships between tuo measures: the Perceived Performance Inventory (PPI) and the videotaped interview. The ?PI looked at perceptions of six skill areas that were largely parallel to the six functions examined by the videotaped interview. The PPI identified the perceptions that different audiences have of an administrator's summarized performance. The videotaped assessment examined specific performances in specified areas and assigned ratings to them. Appended are (1) 10 references; (2) a management profile; and (3) eight data tables. (SI) *******************************************************************x*** r. Reproductions supplied by EDRS are the best that can Le made from the original document. ***********************************************************************
Embryo malposition as a potential mechanism for mercury‐induced hatching failure in bird eggs

We examined the prevalence of embryo malpositions and deformities in relation to total mercury (THg) and selenium (Se) concentrations in American avocet (Recurvirostra americana), black-necked stilt (Himantopus mexicanus), and Forster's tern (Sterna forsteri) eggs in San Francisco Bay (CA, USA) during 2005 to 2007. Overall, 11% of embryos were malpositioned in eggs ≥18 d of age (n = 282) and 2% of embryos were deformed in eggs ≥13 d of age (n = 470). Considering only those eggs that failed to hatch (n = 62), malpositions occurred in 24% of eggs ≥18 d of age and deformities occurred in 7% of eggs ≥13 d of age. The probability of an embryo being malpositioned increased with egg THg concentrations in Forster's terns, but not in avocets or stilts. The probability of embryo deformity was not related to egg THg concentrations in any species. Using a reduced dataset with both Se and THg concentrations measured in eggs (n = 87), we found no interaction between Se and THg on the probability of an embryo being malpositioned or deformed. Results of the present study indicate that embryo malpositions were prevalent in waterbird eggs that failed to hatch and the likelihood of an embryo being malpositioned increased with egg THg concentrations in Forster's terns. We hypothesize that malpositioning of avian embryos may be one reason for mercury-related hatching failure that occurs late in incubation, but further research is needed to elucidate this potential mechanism. Environ. Toxicol. Chem. 2010; 29:1788–1794. © 2010 SETAC
Bargaining under Incomplete Information

This paper presents and analyzes a bargaining model of bilateral monopoly under uncertainty. Under the bargaining rule proposed, the buyer and the seller each submit sealed offers that determine whether the good in question is sold and the transfer price. The Nash equilibrium solution of this bargaining game implies an offer strategy of each party that is monotonic in its own reservation price and depends on its assessment of the opponent's reservation price. Issues of relative bargaining advantage and efficiency are examined for a number of special cases. Finally, we discuss the appropriateness of the Nash solution concept.
Initiation of HPM Surface Flashover

Summary form only given. Surface flashover formation at dielectric/air interfaces during pulsed high power microwave (HPM) excitation can severely limit the power densities which can be transmitted into atmospheric medium. Previous studies on HPM surface flashover in the S-band at 5 MW power levels have reported on the contributing factors to flashover development including the effects of gas type, pressure and relative humidity. Furthermore, analysis on optical emission spectra collected from the developing discharge has determined that the vibrational and rotational temperatures of the plasma are approximately 2700 degK and 300 degK, respectively. In addition to experimental efforts, a Monte Carlo-type electron motion simulation code, MC, has been developed to calculate the increasing electron density during flashover formation. Results from this code have exhibited a quantitative agreement with experimental data over a wide range of atmospheric conditions. A critical parameter to flashover development is the stochastic process involving the appearance of initiatory or "seed" electrons, as seen by the reduction in flashover delay time by approximately 10-20% in the presence of external UV illumination. While the current version of the MC code seeds the flashover location with electron densities on the order of background ion densities produced by cosmic radiation, it fails to incorporate the field assisted collisional detachment processes which are the primary origin of these electrons on the time scales of interest. Investigation of these processes and development of more accurate seeding in the MC code is a key step towards predicting HPM flashover over a wide range of parameters, particularly in the presence of highly electronegative gasses such as SF6 or O2, in which there is an absence of free electrons. Theoretical results of HPM surface flashover with the improved seeding model will be benchmarked against previously measured data obtained with HPM pulse excitation. Further, the slow rise-time data (~500-600 ns risetime) that revealed a distinct reduced field vs. pressure delay time product dependence will be supplemented by short rise-time pulse data.
The Impact of Evaporative Ducting on Covert Communications

This paper provides a brief primer on tropospheric ducting and examines the potential impact that evaporative ducting has on the intercept vulnerability of covert communication systems. The study considers the intercept vulnerability of a generic ship-based satellite terminal in the presence of evaporative ducting when the threat consists of a total power radiometer. The terminal uplink power is computed to achieve a specified bit error rate at the satellite receiver, which is assumed to be at a geosynchronous altitude. The intercept receiver is assumed to operate by processing intercepted energy from the side lobes of the satellite terminal uplink signal. Both near-surface and airborne threat platforms are considered and a vulnerability analysis is performed for different RF frequencies and uplink data rates. The results demonstrate that evaporative ducting is capable of significantly increasing the intercept range of the satellite terminal when the threat is located near the Earth's surface. By comparison, however, the impact of evaporative ducting is shown to be comparatively minor when the threat receiver is on an airborne platform. This paper addresses an important aspect of ducting that is underrepresented in the literature - the linkage between ducting and communication covertness.
Limits to understory plant restoration following fuel-reduction treatments in a piñon-juniper woodland.

National fuel-reduction programs aim to reduce the risk of wildland fires to human communities and to restore forest and rangeland ecosystems to resemble their historical structure, function, and diversity. There are a number of factors, such as seed bank dynamics, post-treatment climate, and herbivory, which determine whether this latter goal may be achieved. Here, we examine the short-term (2 years) vegetation response to fuel-reduction treatments (mechanical mastication, broadcast burn, and pile burn) and seeding of native grasses on understory vegetation in an upland pinon–juniper woodland in southeast Utah. We also examine how wildlife herbivory affects the success of fuel-reduction treatments. Herbaceous cover increased in response to fuel-reduction treatments in all seeded treatments, with the broadcast burn and mastication having greater increases (234 and 160 %, respectively) in herbaceous cover than the pile burn (32 %). In the absence of seeding, herbaceous cover only increased in the broadcast burn (32 %). Notably, fuel-reduction treatments, but not seeding, strongly affected herbaceous plant composition. All fuel-reduction treatments increased the relative density of invasive species, especially in the broadcast burn, which shifted the plant community composition from one dominated by perennial graminoids to one dominated by annual forbs. Herbivory by wildlife reduced understory plant cover by over 40 % and altered plant community composition. If the primary management goal is to enhance understory cover while promoting native species abundance, our study suggests that mastication may be the most effective treatment strategy in these upland pinon–juniper woodlands. Seed applications and wildlife exclosures further enhanced herbaceous cover following fuel-reduction treatments.
Some behavioural and ecological factors affecting distribution, biomass and production of juvenile Atlantic salmon

Observations were made in an experimental stream tank (total area 14.7 m 2 ) on juvenile Atlantic salmon, Salmo salar L (parr), relating experimental observations to field observations, including the reported diurnal fasting behaviour of juvenile salmon at water temperatures <10 °C. Densities in the tank ranged from five to twenty parr, at water temperatures ranging from 4.6 °C to 15.8 °C. The wide channel of the stream tank, with mean water velocity of 18.8 cms 1 , was the preferred section, where territorial behaviour was observed. Biomass was regulated in the wide channel by territorial mosaics or by dominance hierarchies. Dominance hierarchies were reflected in coloration of the fish. Dominant salmon were generally in the wide channel. Densities of salmon parr (of mean fork length 10.2 cm) in the channel ranged from 0.84 m 2 to 1.73 m 2 , with an average biomass of 14.2 gm 2 . Growth was least at the 5.9 °C temperature treatment. In experiments at temperatures below 10 °C, feeding, dominance hierarchy and territorial behaviour were observed in daylight hours, contrary to the published literature. Interactions with other species may affect behaviour. Some observations were made on a closely related species, brown trout (Salmo trutta L.), a commonly cohabiting species in many systems. Trout displaced salmon from their preferred locations in the tank and were more aggressive than the salmon, reducing agonistic behaviour by the salmon. The commonest agonistic act shown by salmon was 'charge' and that by the trout was 'approach'. Some field observations affecting behaviour and production are discussed.
Kinetic Compensation Effect in the Heat Denaturation of Whey Protein

The kinetic compensation effect in the heat denaturation of whey proteins was demonstrated using two different kinetic compensation relationships, i.e. Enthalpy (ΔH≠/Entropy (ΔS≠) compensation and Frequency Factor (In ko)/Activation Energy (Ea) compensation. Isokinetic temperatures determined by these methods were 84.0 and 87.8°C, respectively. These values were higher than those associated with thermal death of microorganisms caused by heat denaturation of proteins; however, they were in the experimental temperature range, correlating well the dependent relationship between kinetic parameters.
LS-TDF: Low-Switching Transition Delay Fault Pattern Generation

Higher chip densities and the push for higher performance have continued to drive design needs. Transition delay fault testing has become the preferred method for ensuring these chips operate at the specified frequency. However, current industrially used X-filling (random-fill or compression) schemes tend to generate transition delay fault patterns with switching activity much higher than what would be seen during functional mode operation of the chip, potentially causing failures that would not occur in the field. In this paper, we present a low- switching transition delay fault pattern generation flow. The flow short-lists patterns based on high switching activity, which is determined by the fault lists of each pattern. Once those patterns with high switching are filtered, they will be replaced by low-switching patterns to recover any lost fault coverage. The proposed pattern generation flow works well with commercial tools and can easily be integrated into an industrial flow.
A Research-Based Use of Tai Chi/Movement Therapy as a Nursing Intervention

Tai Chi has been widely practiced in China for centuries as an art form, religious ritual, relaxation technique, exercise, and a method of self-defense for people of all ages. It has been used to improve balance; promote postural stability; decrease falls; enhance cardiovascular and ventilatory functions; rehabilitate persons with acute myocardial infarction and rheumatoid arthritis; and reduce pain, stress, and nightmares. The purpose of this article is to summarize, synthesize, and critically evaluate the research-based use of Tai Chi presented in the current literature and give implications and directions for future research. Additional studies about the effects of Tai Chi from a nursing perspective are needed to make clear when it is beneficial as a nursing intervention.
On making clinical trials possible

In this issue, we are publishing two contributions deserving of special note. Courtesy of the inimitable David Sackett, we are inaugurating a new column devoted to career advice for the cliniciantrialist, a career path that has become increasingly difficult for many of the reasons that Sackett attempts to address in this series [1]. You will see that the tone and content of the column, like its author, is informal, irreverent, wise, but overall, real. He talks about the life and career management skills that are needed to foster success in this field, in which clinician investigators are desperately needed to assure that clinical trials are asking the right questions, but professional, economic, and social pressures are making it increasingly difficult for them to choose this path. While Sackett’s advice will make the biggest difference for those early in their careers, this non-early-career trialist can testify that it is never too late to receive it. Sackett has all the bona fides to offer such advice, but more importantly, an endless wellspring of good humor and a passionate commitment to nurturing the next generation of clinician researchers. I welcome him to our pages, and look forward to his jovially serious wisdom over at least the next year.
Beam diameter threshold for polarization conversion photoinduced by spatially oscillating bulk photovoltaic currents in LiNbO 3 : Fe

Polarization conversion that is photoinduced by means of spatially oscillating photovoltaic currents in bulk LiNbO3:Fe is studied both experimentally and theoretically. We measured nearly complete ordinary-to-extraordinary conversion for input ordinary beam diameters greater than ∼200 μm and almost no conversion for beam diameters less than ∼60 μm. The extraordinary light was scattered perpendicular to the optic axis into a bow-tie-shaped distribution. To analyze the effect, we use the bulk photovoltaic model to derive coupled-wave equations for arbitrary-direction two-beam coupling (one ordinary wave, one extraordinary wave) and multiple-beam coupling (one ordinary wave, multiple extraordinary waves). We include the effect of beam diameter by using an overlap integral of the interacting beam profiles. The theory correctly models both the experimental three-dimensional distribution of extraordinary scattered light and the total polarization conversion as a function of beam diameter.
Structure, Size, and Solubility of Antigen Arrays Determines Efficacy in Experimental Autoimmune Encephalomyelitis

Presentation of antigen with immune stimulating “signal” has been a cornerstone of vaccine design for decades. Here, the antigen plus immune “signal” of vaccines is modified to produce antigen-specific immunotherapies (antigen-SITs) that can potentially reprogram the immune response toward tolerance of an autoantigen. The codelivery of antigen with a cell adhesion inhibitor using Soluble Antigen Arrays (SAgAs) was previously shown to slow or halt experimental autoimmune encephalomyelitis (EAE), a murine form of multiple sclerosis (MS). SAgAs are comprised of a hyaluronic acid backbone with cografted intercellular cell adhesion molecule-1 ligand derived from αL-integrin (CD11a237–246, “LABL”) and an encephalitogenic epitope peptide of proteolipid protein (PLP139–151, “PLP”). Here, the physical characteristics of the carrier were investigated to evaluate how structure, size, and solubility drive the immune response when treating EAE. A bifunctional peptide (small, soluble), SAgAs (large, soluble), and PLGA nanoparticles (large, insoluble) all displaying PLP and LABL in equimolar ratios were compared. Maximum EAE suppression was achieved with coincident display of both peptides on a soluble construct.
Iron: Heme Proteins & Electron Transport

This chapter discusses the structure and function of cytochromes, which are a class of iron-containing heme proteins primarily involved in biological electron-transfer reactions. Subcellular organelles called mitochondria are responsible for carrying out oxidative phosphorylation, the major energy-transduction process in eukaryotic cells. Enormous progress has been made in our understanding of the molecular mechanism of the mitochondrial electron-transport chain over the past decade. X-ray crystal structures have been determined for three of the four electron-transfer complexes: succinate–ubiquinone reductase, cytochrome bc1, and cytochrome c oxidase (CcO). Cytochrome c (Cc) is a small heme protein with a molecular weight of 12 500 Da that transports electrons from cytochrome bc1 to CcO. It is a very positively charged protein, and is known to bind to both cytochrome bc1 and CcO by means of electrostatic interactions. Extensive chemical modification studies have demonstrated that the binding domain on Cc for both proteins involves lysines immediately surrounding the heme crevice, and Cc functions as a mobile shuttle during electron transport. The reactions of Cc with its redox partners are too fast to resolve by conventional techniques such as stopped-flow spectroscopy. A new method to study biological electron transfer has been introduced that utilizes a photoactive tris(bipyridine)ruthenium complex, Ru(II), which is covalently attached to a protein such as Cc. Photoexcitation of Ru(II) to the metal-to-ligand charge-transfer state, Ru(II*), a strong reductant, leads to rapid electron transfer to the ferric heme group in Cc. Subsequent electron transfer from photoreduced heme c to redox center(s) in another protein can be measured on a timescale as short as 50 ns. This technique has been used to measure intracomplex electron transfer between Cc and its physiological partners, CcO, cytochrome bc1, cytochrome c peroxidase (CcP), and cytochrome b5. The ruthenium technique was used to characterize sequential electron transfer in cytochrome bc1 from ubiquinol to the Rieske iron–sulfur protein (2Fe2S), cytochrome c1, and finally to Cc. Cytochrome oxidase contains four redox centers, CuA, heme a, heme a3, and CuB. A ruthenium Cc derivative was used to demonstrate that the initial site of electron entry into CcO is CuA, followed by electron transfer to heme a, and then heme a3. Keywords: cytochrome c; cytochrome b5; cytochrome c peroxidase; cytochrome c oxidase; cytochrome bc1; ruthenium; mitochondrial electron transfer
Reinforcement of acrylonitrile copolymer by polymer blending

Blends of an acrylonitrile copolymer and a reinforcing polymer were formed by polymerization of the second component in a concentrated solution of the first component. The second component, polyureas or polycarbodiimides, precipitated as an intimate dispersion of particulate domains in the liquid medium. Film or fiber formation by coagulation of the solution containing the second component as particulate matter resulted in a distinct two-phase blend. Reinforcement of the acrylonitrile copolymer was evidenced by significant increases in dry and wet moduli above the glass transition temperature of the polyacrylic component. The blends were characterized with dynamic mechanical testing and optical and electron microscopy. The blends exhibited two glass transitions corresponding to those of the individual components. The phase domains were evident over the compositional range examined. The method of blending is illustrative of effective reinforcement by interpenetration of phases in the absence of compatibility of the components at the macromolecular level.
The Reservisor automated airline reservation system: combining communications and computing

Shortly after the beginnings of the computer in the mid-1940s, a machine appeared that was the first in a long line of important commercial systems integrating communications and processing: the Reservisor airline reservation system built by the Teleregister Corporation. A few parts of the original have been preserved at the Smithsonian Institution, and there are enough records to understand both the basic issues in the airline industry that led to the development of this remarkable device and how the machine helped solve some of the problems of rapidly evolving air-transport technology. This article also discusses the place of the Reservisor in the larger view of the development of information technology. >
Parallel multipole implementation of the generalized Helmholtz decomposition for solving viscous flow problems

The evaluation of a domain integral is the dominant bottleneck in the numerical solution of viscous flow problems by vorticity methods, which otherwise demonstrate distinct advantages over primitive variable methods. By applying a Barnes–Hut multipole acceleration technique, the operation count for the integration is reduced from O(N2) to O(NlogN), while the memory requirements are reduced from O(N2) to O(N). The algorithmic parameters that are necessary to achieve such scaling are described. The parallelization of the algorithm is crucial if the method is to be applied to realistic problems. A parallelization procedure which achieves almost perfect scaling is shown. Finally, numerical experiments on a driven cavity benchmark problem are performed. The actual increase in performance and reduction in storage requirements match theoretical predictions well, and the scalability of the procedure is very good. Copyright © 2003 John Wiley Sons, Ltd.
Comparison of rubidium-82 positron emission tomography and thallium-201 SPECT imaging for detection of coronary artery disease

The diagnostic performance of rubidium-82 (Rb-82) positron emission tomography (PET) and thallium-201 (Tl-201) single-photon emission-computed tomography (SPECT) for detecting coronary artery disease was investigated in 81 patients (52 men, 29 women). PET studies using 60 mCi of Rb-82 were performed at baseline and after intravenous infusion of 0.56 mg/kg dipyridamole in conjunction with handgrip stress. Tl-201 SPECT was performed after dipyridamole-handgrip stress and, in a subset of patients, after treadmill exercise. Sensitivity, specificity and overall diagnostic accuracy were assessed using both visually and quantitatively interpreted coronary angiograms. The overall sensitivity, specificity and accuracy of PET for detection of coronary artery disease (greater than 50% diameter stenosis) were 84, 88 and 85%, respectively. In comparison, the performance of SPECT revealed a sensitivity of 84%, specificity of 53% (p less than 0.05 vs PET) and accuracy of 79%. Similar results were obtained using either visual or quantitative angiographic criteria for severity of coronary artery disease. In 43 patients without prior myocardial infarction, the sensitivity for detection of disease was 71 and 73%, respectively, similar for both PET and SPECT. There was no significant difference in diagnostic performance between imaging modalities when 2 different modes of stress (exercise treadmill vs intravenous dipyridamole plus handgrip) were used with SPECT imaging. Thus, Rb-82 PET provides improved specificity compared with Tl-201 SPECT for identifying coronary artery disease, most likely due to the higher photon energy of Rb-82 and attenuation correction provided by PET. However, post-test referral cannot be entirely excluded as a potential explanation for the lower specificity of Tl-201 SPECT.
Perturbations of weakly resonant power system electromechanical modes

It is not uncommon for oscillatory electric power system modes to move close to a resonance in which eigenvalues coincide. In a weak resonance, the modes are decoupled and the eigenvalues do not interact. We analyze general perturbations of a weak resonance and find two distinct behaviors, including interactions near strong resonances in which the eigenvalues quickly change direction. The possible perturbations are illustrated with interactions between electromechanical modes in a 4-generator power system. Some of the interactions are similar to subsynchronous resonance and can lead to oscillatory instability.
Context processing and context maintenance in healthy aging and early stage dementia of the Alzheimer's type.

Declines in the ability to process context information may represent a fundamental mechanism of age-related cognitive changes. Two components of context processing—activation/updating and maintenance—were examined in a sample of healthy younger and older adults, along with individuals suffering from early stage dementia of the Alzheimer’s type (DAT). All older adult groups showed context activation/updating impairments, whereas context maintenance was only impaired in the oldest adults (age 75 years) and was further exacerbated in DAT individuals. The results suggest that context processing may be composed of functionally dissociable components and point to the utility of this construct in understanding the timecourse of cognitive decline in healthy and pathological aging.
Room Temperature Instabilities Observed on Silicon Gate Devices

A room temperature ionic instability has been observed on p-channel silicon gate MOS devices processed in a specific manner. This instability appears as a rapid and substantial change of threshold voltage at room temperature consistent with a fast moving ionic species in the gate oxide region. The diffusion constant of this species, measured over the temperature range from 0°C to 75°C is consistent with extrapolated data for H+ ions in SiO2. The magnitude of the room temperature threshold shift is voltage dependent and exists independently of any Na+ contamination. Correctly processed silicon gate devices are completely stable.