cssi/SciSciGPT-SciSciNet huggingface dataset:
AWSM: Allocation of workflows utilizing social network metrics

The primary contribution of this work is a methodology that serves as a decision support tool to create teams of human actors within an organization to perform workflows, based on optimizing social network (SN) measures of choice, such as group or team cohesiveness. Past literature shows that the constituent activities of the workflows will be performed with greater efficiency and/or effectiveness if the workgroup of actors is optimized along an SN measure such as group cohesiveness. The major contribution here is the creation and implementation of a formal generalized methodology we call AWSM (Allocation of Workflows with Social Network Metrics) that incorporates ideas from two diverse fields: social network theory and workflow modeling, and allows optimization of work groups along any SN metric. In order to implement this model we present newly created algorithms to structure and represent the problem so that standard integer programming solvers can be utilized to solve it. We also present a performance analysis of the AWSM methodology and empirically test its feasibility for solving real world sized problems.
Antitumor agents 1871: Synthesis and cytotoxicity of substituted 8,8-dimethyl-2H,8H-pyrano[6,5-h]quinoline-2-one and related compounds

Several substituted 8,8-dimethyl-2H,8H-pyrano[6,5-h]quinoline-2-ones and related compounds were synthesized and evaluated for their in vitro cytotoxicity against a panel of human tumor cell lines. The most active compound (3) showed significant cytotoxic activity with GI50 values in the micromolar range.
Elastomeric Ionic Hydrogel Sensor for Large Strains

An elastomeric hydrogel membrane containing dissolved salt is demonstrated to be a linear strain sensor for large strains up to 25%. AC sensing circuitry allows the ionic conductor to function as a sensor without polarization effects. The homogeneous gel is shown to be lacking a relaxation or hysteresis response found in the soft composite piezoresistors that are commonly used for large strain sensing. This allows operation of the sensor with minimal post-processing and increased accuracy during real-time operation. The gauge factor of the gel sensor is shown to be near two, consistent with the observation that the strain sensing of the material is solely derived from the deformation of the bulk. The very low Young's modulus of the gel (~1 kPa) allows deformation of a fabric substrate to be followed without significantly constraining the fabric. A prototype sleeve that uses these sensors for proprioceptive sensing of joint angle motion on a robotic arm is demonstrated as a potential application. Water loss from the hydrogel due to evaporation from the surface is slow. We show that the resulting trend in the impedance of the sensor can be easily corrected by simple signal processing.
Effects of Fluctuating and Constant Temperatures on Early Development and Survival of Colorado Squawfish

Abstract A laboratory study was conducted to determine the effects of four constant temperatures (18, 22, 26, and 30°C) and three fluctuating temperatures (diel fluctuations of ±2.5°C around 18, 22, and 26°C) on early development and survival of Colorado squawfish Ptychocheilus lucius, which is listed as an endangered species by the U.S. Department of the Interior. Average hatch in constant and fluctuating temperatures was 72% at 18°C, 67% at 22°C, 62% at 26°C, and 38% (constant temperature only) at 30°C. There was no significant difference in hatch between constant and fluctuating temperatures. Average survival of larvae to 7 d posthatch in constant and fluctuating temperatures was 68% at 18°C, 64% at 22°C, 83% at 26°C, and 13% (constant temperature only) at 30°C. Survival of larvae at 30°C may have been confounded by a relatively low hatch of embryos and poor condition of larvae. Survival of larvae was 10–31% higher in fluctuating than in constant temperatures. Incidence of abnormalities was 2–22% at 18...
The Last Glacial Maximum: stability and change in a western Amazonian cloud forest

The climatic and vegetation history of a western Amazonian cloud forest is documen- ted in a continuous pollen record spanning the full last glacial period between 43.5 and 22k cal. yr BP. The chronology for this record is based on eight radiocarbon dates yielding a low-resolu- tion pollen analysis for the region. A bioclimatic envelope model was generated on the basis of mod- ern altitudinal distributions and the pollen data, which produced a glacial palaeotemperature estimate of ca. 5 C relative to present. Palaeoecological evidence of continuous moist cloud forest cover in the basin indicates that western Amazonian forests were not fragmented during the LGM. This evidence supports wet conditions in western Amazonia at the LGM and further refutes hypotheses of Amazonian aridity during the last ca. 44k cal. yr BP. Copyright 2005 John Wiley & Sons, Ltd.
Significant enhancement of optical absorption through nano-structuring of copper based oxide semiconductors: possible future materials for solar energy applications.

The optical absorption coefficient is a crucial parameter in determining solar cell efficiency under operational conditions. It is well known that inorganic nanocrystals are a benchmark model for solar cell nanotechnology, given that the tunability of optical properties and stabilization of specific phases are uniquely possible at the nanoscale. A hydrothermal method was employed to fabricate nanostructured copper oxides where the shape, size and phase were tailored by altering the growth parameters, namely the base media used, the reaction temperature, and the reaction time. The nano crystalline structures, phases, morphology, molecular vibrational modes, and optical properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence (PL), and UV-vis spectroscopy. A significantly large optical absorption coefficient, of the order of twice that of Si in the visible range, was observed in a particular phase mixture of nanostructured copper oxides. An optical absorption coefficient of 7.05 10+5 cm−1 at 525 nm was observed in a particular nanostructured phase mixture of copper oxides which is appreciably larger than commercially pure CuO (1.19 10+5 cm−1) and Si (1.72 10+5 cm−1). A possible mechanism of formation of phase mixtures and morphology of copper oxides has also been discussed, which opens up a roadmap in synthesis of similar morphology nanostructures for efficient solar cells.
Commentary on the Keynote Lecture Presented by Dr. Jonathan Shay, Friday, June 27, 2008 titled The Trials of Homecoming: Odysseus Returns from Iraq/Afghanistan, and additional reflections

After many years of appreciating the clinical wisdom advanced by Dr. Jonathan Shay in his groundbreaking books titled Achilles in Vietnam: Combat Trauma and the Undoing of Character and Odysseus in...
The Depiction of Female Models in Sport Television Commercials in the United States by Degree of Slenderness: An Appraisal

This manuscript narrates the results of an examination of the portrayal of the degree of slenderness of female models in sport marketing television commercials in the United States. A visual content analysis was employed to gather and to interpret the data. In turn, the analysis revealed that the commercials utilized substantial numbers of models who were inordinately slender, depicted these models more favorably than they did heavier models, and presented them in a fashion that pointed to superior social status and hierarchy positions.
Course development for web-based nursing education programs

Developing and launching online programs requires nurse educators to reframe content and rethink traditional teaching methodologies. Creating a framework for course design and standardization of templates can result in online learning that is student centered while allowing the institution to scale up enrollment with quality education at the core. This article explores the considerations needed for effective, interactive online course delivery in nursing education. Working in conjunction with other university technology stakeholders, nurse educators can select the learning management system with the features that will work best for the program, develop the course structure and organization through adherence to template rules for both syllabi and course modules, and develop appropriate learning activities to assure student exposure to content identified in the course objectives. With these structure pieces in place process becomes the second focus for nurse educators in online programs. Process activities for active engagement are discussed.
Constrained information minority game: How was the night at El Farol?

Abstract We introduce a variation of the El Farol Game in which the only players who surely know the outcome of the last turn of the game are those who actually attended the bar. Other players may receive this information with reduced probability. This information can be transmitted by another player who actually attended the bar in the last turn of the game or from the media. We show that since this game is not organized around the socially optimal point, arbitrage opportunities may arise. Therefore, we study how these opportunities can be exploited by an agent. An interesting application of this model is the market of goods being auctioned, such as cars being repossessed. The results obtained here seem to closely reflect the dynamics of this market in Brazil.
Sexual and reproductive health needs assessment with deaf people in Ghana: Methodological challenges and ethical concerns.

Background: Deafness is a complex and multifaceted phenomenon. The different ways of perceiving and understanding deafness have practical implications for research with deaf people. Whilst the deaf community is not homogenous, it is generally distinct from the hearing population. Consequently, the appropriateness of applying research methods and informed concern processes designed for the hearing population in research with deaf people has been questioned. Objectives: This article reflected on some methodological challenges and ethical concerns arising from conducting a sexual and reproductive health needs assessment with deaf people in Ghana. The aim was to provide some perspectives on some of the challenges associated with doing research with deaf people. Method: The study was a two phase, sequential, mixed methods design, consisting of three focus groups to assist in the development of a survey and then the implementation of the survey for needs assessment data collection. The number of participants in the study was 179, consisting of 26 focus group participants: 7 executives of the Ghana National Association of the Deaf (GNAD), 10 male adults, and 9 female adults. There were 152 survey respondents (students, women and men) and one key informant. All participants, except the key informant, were deaf people. Results: The application of traditional research methods to studies involving deaf participants presents numerous methodological and ethical dilemmas associated mainly with deaf people’s unique cultural and linguistic characteristics. Conclusion: Research methods should not be taken as universal guidelines for conducting research in all settings because of differences in settings.
The treatment of traction-free boundary condition in three-dimensional dislocation dynamics using generalized image stress analysis

Abstract Recent attention has been given to the proper treatment of the planar traction-free surfaces which typically bound a computational box in three-dimensional dislocation dynamics. This paper presents an alternative to the use of the finite-element method for this purpose. Here, to annul the tractions produced by a sub-surface dislocation segment on a finite-area free surface S , a combination of an image dislocation segment, and a distribution of N prismatic rectangular Volterra dislocation loops meshing S is utilized. The image dislocation segment, with the proper sign selection of the Burgers vector components, annuls the shear stresses, and the normal stress component is annulled discretely at N collocation points representing the centers of the loops. The unknowns in this problem are the magnitudes of the N Burgers vectors for the loops. Once these are determined, one can back calculate the Peach–Koehler force acting on the sub-surface segment and representing the effect of the free surface. As expected, the accuracy of the method improves as the loops continuously decrease in size.
Feasibility of an early Alzheimer's disease immunosignature diagnostic test

Abstract A practical diagnostic test is needed for early Alzheimer's disease (AD) detection. Immunosignaturing, a technology that employs antibody binding to a random-sequence peptide microarray, generates profiles that distinguish transgenic mice engineered with familial AD mutations (APPswe/PSEN1-dE9) from non-transgenic littermates. It can also detect an AD-like signature in humans. Here, we assess the changes in the immunosignature at different time points of the disease in mice and humans. We also evaluate the accuracy of the late-stage signature as a test to discriminate between young mice with familial AD mutations from non-transgenic littermates. Plasma samples from AD patients were assayed 3–12 months apart, while APPswe/PSEN1-dE9 and non-transgenic controls supplied plasma at monthly intervals until they reached 15 months of age. Microarrays with 10,000 random-sequence peptides were used to compare antibody binding patterns. These patterns gradually changed over the life-span of mice. Strong, characteristic signatures were observed in transgenic mice at early, mid and late stages, but these profiles had minimal overlap. The signature of young transgenic mice had an error rate of 18% at classifying plasma samples from late-stage transgenic mice. Conversely, the late-stage transgenic mice signature discriminated between young transgenic mice and littermates with an error rate of 21%. Less distinctive profiles were recognizable throughout the transgenic mice lifespan, being detectable as early as 2 months. The human signature had minimal change on short-term follow-up. Our results call for a reappraisal of the way incipient AD is studied, as biomarkers seen in late-stages of the disease may not be relevant in earlier stages.
The Structure of the Biblioblogosphere: An Examination of the Linking Practices of Institutional and Personal Library Blogs

The biblioblogosphere is comprised of the institutional publication of blogs of libraries and the personal, professionally-oriented publication of blogs by librarians. Since introduction of this neologism in 2004, a number of researchers have examined this particular class of bloggers and blogging. However, there is limited investigation into the structure and connectivity of blogs within the biblioblogosphere. This article reports a study of interlinkage patterns within a sample of 1,604 biblioblogs. Findings suggest the biblioblogosphere conforms to the locally dense, globally sparse structure of blog networks established by previous studies of other blog types. The majority of blogs within the sample did not link to any other sampled blog. Those that did tended to cluster according to library type, blog subject, or geographical proximity. About one-third of the interlinked blogs were located within a single, massive component (that is, a networked group of blogs), while the rest were in smaller network...
Parallel worlds converge

Abstract The Nature of Disease in Plants by R.P. Scheffer Cambridge University Press, 1997. £45.00/$64.95 hbk (ix +325 pages) ISBN 0 521 48247 X
Mo calculation study of the fluorinating reaction of N-fluoropyridinium salts

Abstract N-fluoropyridinium salts (I) react with carbon nucleophiles by F transfer1). In order to investigate the mechanism of the reaction and substituent effect on the pyridine rings, the heat of formation and charge distributions of various N- fluoropyridinium cations and corresponding pyridine derivatives are calculated by semiempirical and ab initio MO methods. The calculation results show that the cation has small negative charge on N and positive charges on ortho C's, and well interpret the by-products of this reaction1). The fluorinating power is related to the NF bond disassosiation energies and they depend on the F charges (not N charges). The possible reaction mechamism and intermediate will be discussed.
Sudden cardiac death in athletes: a guide for emergency physicians

A conditioned athlete is usually regarded as a member of the healthiest segment of society, and exercise itself is looked upon as a means to improve health. Although extremely uncommon, sudden cardiac death (SCD) in young athletes is a devastating medical event to all involved (patient, family, community, team, and caregivers). Most etiologies of SCD in athletes result in the same final common denominator (cardiac arrest) on presentation to an emergency physician. There are, however, certain historic, physical examination, and electrocardiographic features of many of these disease processes that emergency physicians should have a working knowledge of to try to identify them before they result in SCD. This review examines the clinical presentation, diagnostic techniques, and management options applicable to emergency practitioners.
Significance of the imaginary part of the weak value

Unlike the real part of the generalized weak value of an observable, which can in a restricted sense be operationally interpreted as an idealized conditioned average of that observable in the limit of zero measurement disturbance, the imaginary part of the generalized weak value does not provide information pertaining to the observable being measured. What it does provide is direct information about how the initial state would be unitarily disturbed by the observable operator. Specifically, we provide an operational interpretation for the imaginary part of the generalized weak value as the logarithmic directional derivative of the postselection probability along the unitary flow generated by the action of the observable operator. To obtain this interpretation, we revisit the standard von Neumann measurement protocol for obtaining the real and imaginary parts of the weak value and solve it exactly for arbitrary initial states and postselections using the quantum operations formalism, which allows us to understand in detail how each part of the generalized weak value arises in the linear response regime. We also provide exact treatments of qubit measurements and Gaussian detectors as illustrative special cases, and show that the measurement disturbance from a Gaussian detector is purely decohering in the Lindblad sense, which allows the shifts for a Gaussian detector to be completely understood for any coupling strength in terms of a single complex weak value that involves the decohered initial state.
Outcome of patients with micropapillary urothelial carcinoma following radical cystectomy: ERBB2 (HER2) amplification identifies patients with poor outcome

Micropapillary urothelial carcinoma exhibits amplification of the human epidermal growth factor receptor, ERBB2(HER2), and overexpression of the ERBB2 protein product. The clinical significance of this has yet to be established. The objective of this study was to examine ERBB2 amplification and protein expression in micropapillary urothelial carcinoma and stage-matched typical urothelial carcinoma treated by radical cystectomy to assess the frequency of amplification and protein expression, and to determine the association with cancer-specific survival. Pathologic material and data from patients undergoing cystectomy at Mayo Clinic between 1980 and 2008 were reviewed. ERBB2 amplification by fluorescence in situ hybridization (FISH) and protein expression by immunohistochemistry were assessed. Univariate and multivariate Cox proportional hazards regression models were used to evaluate for associations of ERBB2 amplification and protein expression with survival. ERBB2 amplification was identified in 9 (15%) of 61 micropapillary carcinomas compared with 9 (9%) of 100 urothelial carcinomas. In patients with micropapillary carcinoma, ERBB2 amplification was associated with a nearly threefold increased risk of cancer death. ERBB2 amplification (hazard ratio 4.3; P=0.0008) remained associated with an increased risk of death from bladder cancer among patients with micropapillary urothelial carcinoma on multivariate analysis. The association of cancer-specific survival and ERBB2 amplification was not seen in patients with urothelial carcinoma. ERBB2 immunohistochemistry correlated with ERBB2 amplification but there was no association of ERBB2 protein expression and survival. ERBB2 amplification is more frequent in micropapillary urothelial carcinoma than typical urothelial carcinoma, and patients with micropapillary carcinoma who have ERBB2 amplification have worse cancer-specific survival than those who do not. Identification of ERBB2 amplification in micropapillary carcinoma could provide important prognostic information and possibly provide a role for ERBB2 targeted therapy.
Non-Separable Two-Dimensional Perfect Reconstruction Filter Banks

Non-separable filter banks are studied for general two-dimensional sub-band coding. The developed results are valid for any sub-sampling pattern. A synthesis structure is given which enables cascade-structure design of all two-dimensional paraunitary perfect reconstruction filter banks. The resulting structure is evaluated with regard to free variables and computational complexity. The synthesis structure is also extended to embrace non-paraunitary perfect reconstruction systems. Finally, conditions are derived to test filter banks for linear phase in the polyphase domain.
Clinical Expertise in Psychotherapy: How Expert Therapists Use Theory in Generating Case Conceptualizations and Interventions

Case conceptualization is a primary skill that may be the linchpin of clinical practice as it sets the framework for making sense of a patient’s difficulties and guides a path toward change. Providing meaning and structure to often ambiguous and nuanced clinical information, an apt case conceptualization facilitates the therapist’s complex integration of core therapeutic skills to produce expert performance. Rooted in the cognitive sciences literature on expertise, we introduce the concept of metabolizing theory to capture expert therapists’ capacity to use theoretical and clinical knowledge in an intuitive, flexible manner that responds and adapts to the unique and complex context of the treatment.
Understanding β-Hydride Eliminations from Heteroatom Functional Groups

Using density functional theory, we investigated detailed aspects of the quintessential organometallic process, β-hydride elimination (BHE). In general, we find that most BHE processes from alkyl functional group β-atoms are facile, while BHE processes from heteroatom functional groups (N and O) are prohibitively high in energy. We present calculated molecular orbitals and atomic NBO charges obtained from snapshots along reaction profiles to present a qualitative overview for how heteroatoms adversely affect these processes. We discuss these results to provide an illustration for how these processes proceed, clarifying a sometimes oversimplified model for these reactions.
Overcoming apoptosis: new methods for improving protein-expression systems

Cellular suicide, or apoptosis, is responsible for a significant proportion of cell death in many bioprocesses. With the progressive elucidation of the biochemical and genetic events leading to this form of cell death, it is now possible to implement strategies for extending the productive lifetimes of cells in culture. These strategies may include nutritional, genetic and chemical methods that enhance cell survival and performance during the critical stages of a culture process, leading to improvements in the production capacity for valuable biotechnological products.
Cherenkov radiation dosimetry in water tanks - video rate imaging, tomography and IMRT & VMAT plan verification

This paper presents a survey of three types of imaging of radiation beams in water tanks for comparison to dose maps. The first was simple depth and lateral profile verification, showing excellent agreement between Cherenkov and planned dose, as predicted by the treatment planning system for a square 5cm beam. The second approach was 3D tomography of such beams, using a rotating water tank with camera attached, and using filtered backprojection for the recovery of the 3D volume. The final presentation was real time 2D imaging of IMRT or VMAT treatments in a water tank. In all cases the match to the treatment planning system was within what would be considered acceptable for clinical medical physics acceptance.
Extracellular traps are associated with human and mouse neutrophil and macrophage mediated killing of larval Strongyloides stercoralis

Neutrophils are multifaceted cells that are often the immune system's first line of defense. Human and murine cells release extracellular DNA traps (ETs) in response to several pathogens and diseases. Neutrophil extracellular trap (NET) formation is crucial to trapping and killing extracellular pathogens. Aside from neutrophils, macrophages and eosinophils also release ETs. We hypothesized that ETs serve as a mechanism of ensnaring the large and highly motile helminth parasite Strongyloides stercoralis thereby providing a static target for the immune response. We demonstrated that S. stercoralis larvae trigger the release of ETs by human neutrophils and macrophages. Analysis of NETs revealed that NETs trapped but did not kill larvae. Induction of NETs was essential for larval killing by human but not murine neutrophils and macrophages in vitro. In mice, extracellular traps were induced following infection with S. stercoralis larvae and were present in the microenvironment of worms being killed in vivo. These findings demonstrate that NETs ensnare the parasite facilitating larval killing by cells of the immune system.
Dioxygen Affinities of Some Synthetic Cobalt Schiff Base Complexes

The synthesis and dioxygen affinities of six cobalt(II) Schiff base complexes in diglyme solution in the presence of excess aromatic bases are reported. The cobalt(II) chelates investigated are bis-salicylaldehydetetramethylethylenediiminocobalt(II) (CoSALTMEN), bis-salicylaldehyde-o-phenylenediiminocobalt(II) (CoSALOPHEN), bis-(2-hydroxyacetophenone)-ethylenediiminocobalt(II) (Co CH3SALEN), bis-(3,5-dichlorosalicylaldehyde)-o-phenylenediiminocobalt(II) (Co35ClSALOPHEN), bis-(3-methoxysalicylaldehyde)-o-phenylenedi iminocobalt(II) (Co3Me0SAL0PHEN), and the parent compound, bis-salicylaldehydeethylenediiminocobalt(II) (SALCOMINE). Axial bases employed are pyridine, 4-methylpyridine, 4-dimethylaminopyridine, and 4-cyanopyridine. In the solvent medium employed the Schiff base chelates combine with only one axial base; no 2:1 adducts were observed. Electronwithdrawing substituents on the Schiff bases were found to decrease the affinity of the cobalt Schiff base for dioxygen. Equilibrium dioxygen uptake measurements over a range of temperatures provide values of ΔH° and ΔS° of oxygenation which fall in the range -6 to -13 kcal mole-1 for ΔH° and -30 to -52 cal degree-1 mole-1 for AS°, and are in line with values reported for analogous dioxygen complexes in the literature.
Separation mechanism of chiral impurities, ephedrine and pseudoephedrine, found in amphetamine-type substances using achiral modifiers in the gas phase.

A new mechanism is proposed that describes the gas-phase separation of chiral molecules found in amphetamine-type substances (ATS) by the use of high-resolution ion mobility spectrometry (IMS). Straight-chain achiral alcohols of increasing carbon chain length, from methanol to n-octanol, are used as drift gas modifiers in IMS to highlight the mechanism proposed for gas-phase separations of these chiral molecules. The results suggest the possibility of using these achiral modifiers to separate the chiral molecules (R,S) and (S,R)-ephedrine and (S,S) and (R,R)-pseudoephedrine which contain an internal hydroxyl group at the first chiral center and an amino group at the other chiral center. Ionization was achieved with an electrospray source, the ions were introduced into an IMS with a resolving power of 80, and the resulting ion clusters were characterized with a coupled quadrupole mass spectrometer detector. A complementary computational study conducted at the density functional B3LYP/6-31g level of theory for the electronic structure of the analyte–modifier clusters was also performed, and showed either “bridged” or “independent” binding. The combined experimental and simulation data support the proposed mechanism for gas-phase chiral separations using achiral modifiers in the gas phase, thus enhancing the potential to conduct fast chiral separations with relative ease and efficiency.
The infrared spectrum and structure of crystalline ferrocene

Abstract The infrared spectrum of a single crystal of ferrocene has been obtained using polarized radiation. Some vibrational bands have been observed which were not obtained in vapor and solution spectra. The observed spectrum supports the vibrational assignment of Lippincott and Nelson . The polarization data indicate that the molecular symmetry axis lies nearly in the t1t2 plane of the unit cell and that the angle between the molecular symmetry axis and the t2 axis is approximately π/γ.
Histone H1 Depletion Impairs Embryonic Stem Cell Differentiation

Pluripotent embryonic stem cells (ESCs) are known to possess a relatively open chromatin structure; yet, despite efforts to characterize the chromatin signatures of ESCs, the role of chromatin compaction in stem cell fate and function remains elusive. Linker histone H1 is important for higher-order chromatin folding and is essential for mammalian embryogenesis. To investigate the role of H1 and chromatin compaction in stem cell pluripotency and differentiation, we examine the differentiation of embryonic stem cells that are depleted of multiple H1 subtypes. H1c/H1d/H1e triple null ESCs are more resistant to spontaneous differentiation in adherent monolayer culture upon removal of leukemia inhibitory factor. Similarly, the majority of the triple-H1 null embryoid bodies (EBs) lack morphological structures representing the three germ layers and retain gene expression signatures characteristic of undifferentiated ESCs. Furthermore, upon neural differentiation of EBs, triple-H1 null cell cultures are deficient in neurite outgrowth and lack efficient activation of neural markers. Finally, we discover that triple-H1 null embryos and EBs fail to fully repress the expression of the pluripotency genes in comparison with wild-type controls and that H1 depletion impairs DNA methylation and changes of histone marks at promoter regions necessary for efficiently silencing pluripotency gene Oct4 during stem cell differentiation and embryogenesis. In summary, we demonstrate that H1 plays a critical role in pluripotent stem cell differentiation, and our results suggest that H1 and chromatin compaction may mediate pluripotent stem cell differentiation through epigenetic repression of the pluripotency genes.
Properties of temperature-sensitive mutants of parainfluenza virus type 3 selected during the course of persistent infection.

We investigated properties of thets mutants that were selected during the course of persistent infection of Vero cells by parainfluenza virus type 3. The mutants demonstrated leakiness when infecting cells at high MOI and interfered with the growth of wild type virus, apparently by inhibiting a step prior to RNA synthesis.
Repetitive behaviours in anorexia nervosa, autism, and obsessive–compulsive personality disorder

Abstract Restricted and repetitive behaviours and interests (RRBs) greatly contribute to the burden of psychiatric illness for the individual and his or her family. While as a class the presence of RRBs may evidence continuity, the form of the behaviour may change. Further, a given individual may exhibit a multitude of RRBs that compromise different areas of functioning. In eating disorders, individuals may exhibit RRB before eating disorder diagnosis. These behaviours may compromise or complicate treatment, and they may persist following eating disorder improvement. Strategies to organize these behaviours within an individual may facilitate the efficiency of management, while searching for parallel manifestations in RRBs across diagnostic syndromes may guide novel hypothesis generation on underlying biological mechanisms. This article illustrates this strategy by examining potential symptom overlap in the expression of RRBs in individuals with anorexia nervosa, obsessive–compulsive personality disorder, and autism.
From Physiology to Fitness: The Costs of a Defensive Adaptation in Rattlesnakes

Abstract The costs of using and maintaining presumed adaptations are unknown for most animals. Energetically expensive traits, such as some agonistic and antipredator behaviors in animals, may incur trade‐offs with other aspects of an animal’s life history, such as feeding and reproduction. However, infrequent and brief use may reduce the costs of vigorous behaviors. The shaker muscles in the tails of rattlesnakes are an excellent system for studying the potential costs of a specialized defensive system. The high energetic cost of rattling may increase feeding requirements or use energy that could otherwise be available for reproduction. I used energetic modeling to test whether the cost of rattling in western diamond‐backed rattlesnakes (Crotalus atrox) can be high enough to increase feeding demands or reduce fecundity and fitness. Only very frequent and prolonged rattling would increase feeding needs and perhaps reduce fecundity to some degree. Typically, rattling probably incurs very low costs to feedi...
Outcomes-based computer science education

As computer science educators, we are being pushed to define (by accreditation agencies, within our institutions, etc.) our courses and programs in terms of measurable outcomes. The Computing Accreditation Commission (CAC) is responsible for reviewing and accrediting computer sciences departments across the United States. As part of this review process, computer science departments must specify and measure student learning objectives and outcomes (see criteria at http://www.abet.org/cac1.html). The same is true for institution-wide accreditation (for example, by the Middle States Commission on Higher Education). Also, faculty who are composing proposals for NSF or other funding agencies are expected to provide descriptions of objectives and outcomes and how these are to be measured.
Delight by Design: The Role of Hedonic Versus Utilitarian Benefits

Abstract What is the relationship between product design benefits (hedonic versus utilitarian) and the postconsumption feelings of customer delight and satisfaction? The primary insights this research provides are as follows: (1) Products that meet or exceed customers' utilitarian needs and fulfill prevention goals enhance customer satisfaction (e.g., a car with antilock brakes and vehicle stability assist), and (2) products that meet or exceed customers' hedonic wants and fulfill promotion goals enhance customer delight (e.g., a car with panoramic sunroof and six-speaker audio system). Furthermore, the research finds that the primary antecedent feelings of satisfaction are the prevention emotions of confidence and security provided by utilitarian benefits, whereas the primary antecedent feelings of delight are the promotion emotions of cheerfulness and excitement provided by hedonic benefits. Finally, the results show that delighting customers improves customer loyalty, as measured by word of mouth and r...
Molecular location of the genetic lesion in the acatalasemic mouse.

Antibody to normal mouse catalase will stabilize blood and liver catalase of the acatalasemic mouse against a variety of agents which damage protein tertiary structure (urea, guanidine, trypsin) but not against agents which affect the heme group (azide, hydroxylamine). The antibody will also stabilize catalase against inhibition by 3-amino 1,2,4-triazole (AT), the specific site of action of which is known. The antibody is able also to protect normal mouse catalase from urea denaturation, but it is without effect on AT inhibition of normal catalase. A hypothesis is proposed which explains these results and which helps localize the site of the mutation on the catalase molecule.
Effects of estrogen replacement therapy on PET cerebral blood flow and neuropsychological performance

Reports that estrogen may protect against age-associated memory decline and Alzheimer's Disease have kindled interest in the effects of estrogen replacement therapy (ERT) on cognition and brain function. As part of a 9-year study in the Baltimore Longitudinal Study of Aging, we are performing annual magnetic resonance imaging, positron emission tomography (PET), and neuropsychological assessments to examine brain structure and function in individuals aged 55 and older. PET measurements of regional cerebral blood flow (rCBF) are obtained under 3 conditions: rest and verbal and figural delayed recognition memory tasks. Fifteen women receiving ERT (with or without the addition of progesterone) were compared with a matched sample of 17 untreated women. There were no significant differences between groups in regional brain volumes or ventricular size. However, ERT users and nonusers showed significant differences in PET-rCBF relative activation patterns during the memory tasks. During verbal memory processing, there were significant interactions in rCBF activations for the right parahippocampal gyrus, right precuneus, right frontal regions, and left hypothalamus. During figural memory processing, significant interactions were observed for right parahippocampal and inferior parietal regions and for left visual association and anterior thalamic regions. ERT users also showed better performance on neuropsychological tests of figural and verbal memory and on some aspects of the PET activation tests, although the two groups did not differ in education, overall verbal ability, or performance on other neuropsychological tests. These findings confirm our previous observation of the beneficial effects of ERT on figural memory. Moreover, differences in rCBF activation patterns between ERT users and nonusers suggest an area for future research to examine mechanisms through which ERT may influence memory and other cognitive abilities.
Importance of Distributional Form in Characterizing Inputs to Monte Carlo Risk Assessments

The selection among distributional forms for inputs into uncertainty and variability (e.g., Monte Carlo) analyses is an important task. This paper considers the importance of distributional selection by examining the overall and tail behavior of the lognormal, Weibull, gamma, and inverse gaussian distributions. It is concluded that at low relative standard deviation (below 1), there is less of a difference between upper tail behavior among the distributions than at higher RSD values. Sample sizes in excess of 200 are required to reliably distinguish between distributional forms at the higher RSD values. The likelihood statistic appears to offer a reasonable approach to distributional discrimination, and it, or a similar approach, should be incorporated into distributional fitting procedures used in risk analysis.
Ferroelectrics: Start the presses

A simple nanoimprinting method creates arrays of ferroelectric polymer structures suitable for low-cost, non-volatile memories.
Children with cerebral palsy effectively modulate postural control to perform a supra-postural task.

The purpose of this study was to determine whether signatures of adaptive postural control remain present in children with cerebral palsy (CP) when they performed a supra-postural task (i.e., a task performed above and beyond the control of posture) requiring them to balance a marble inside a tube held in the hands. Measures of center of pressure (COP) dynamics (how regular or predictable were the COP data as quantified by the sample entropy metric) and variability (as quantified by the COP standard deviation) were obtained from a sample of children with CP (n = 30) and compared to the same measures taken from typically developing (TD) children. Children with CP demonstrated an apparent inefficiency in postural control (greater irregularity, greater sway variability) relative to TD peers during a quiet-stance (no supra-postural task) condition (p < .05). During supra-postural task performance, those differences were attenuated, though they remained statistically different (p < .05). The findings illustrate flexibility and adaptability in the postural control system, despite the pathological features associated with CP.
Molecular dynamics simulation of hindered diffusion in microcapillaries

A general model for diffusion in membranes is employed to illustrate that the individual contributions of diffusion relative to the membrane and self-diffusion in the pore fluid are simply related to the autocorrelation function for the instantaneous centre of mass velocity of the pore fluid and the usual autocorrelation function for the particle velocities. These results are used to analyse molecular dynamics simulation data for hindered diffusion of rigid sphere fluids in cylindrical pores over a wide range of pore fluid densities and pore sizes. Two reflection conditions, specular and diffuse scattering from the pore wall, are also investigated. The results obtained for diffuse scattering are in qualitative agreement with experimental data reported in the literature. These results also suggest that dense fluids and liquids may undergo a small, nonzero degree of slip during flow past a rigid boundary.
An approximate model for nonlinear dispersion in monochromatic wave propagation models

Abstract A method is proposed for smoothly matching an approximate, shallow-water dispersion relation to an analytically obtained relation for intermediate and deep water. The method provides a correct limit for increasing water depth in the case of weakly non-linear waves, and provides a smooth prediction of wave parameters for the entire range of water depth. The model is applied to a parabolic equation form of the combined refraction-diffraction model, and numerical results are presented in comparison to published data.
Maternal complications and sudden infant death in families with mutations in mitochondrial trifunctional protein

Mitochondrial trifunctional protein (TFP) catalyzes the final 3 steps of long chain fatty acid oxidation. Patients with TFP mutations have either isolated deficiency of long chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) or complete TFP deficiency of all 3 enzymes. Recently, we characterized the genotypes and phenotypes in pediatric TFP defects and documented an association between fetal LCHAD deficiency and maternal liver disease (Ibdah et al, N. Engl. J. Med. 340:1723-31, 1999). To further characterize the association between TFP mutations, pregnancy outcome, and sudden infant death, we analyzed the pregnancy history and offspring genotypes and phenotypes in all affected and non-affected pregnancies in 31 families with mutations in TFP. 26 of these families had offspring with isolated LCHAD-deficiency and 5 with complete TFP deficiency. In 75 pregnancies, 72% of women who carried affected fetuses with isolated LCHAD deficiency developed acute fatty liver of pregnancy, HELLP syndrome or preeclampsia. 64% and 42% of pregnancies carrying fetuses with isolated LCHAD deficiency or complete TFP deficiency were also associated with premature delivery and birth weight that was small for gestational age, respectively. All pregnancies with heterozygous or wild-type fetal genotypes were uncomplicated. 39% (12/31) of the affected children died. Ten with isolated LCHAD deficiency and 2 with complete TFP deficiency. Four of these children had sudden, unexplained death at few months of age and certified initially as SIDS. Autopsy revealed micro- and macro- vesicular hepatic steatosis. Screening for TFP mutations revealed homozygosity for the prevalent (G1528C, E474Q) mutation in all four children. In five families, there was a history of sudden, unexplained death in a sibling of unknown genotype. These results document that: 1) fetal genotype affects both maternal and fetal outcomes in families with TFP mutations; 2) affected children, if unrecognized and untreated, may suffer sudden death. [Supported by a grant from NIH (DK-02574) and a grant from March of Dimes (#6-FY99-376)]
Nuclear Fission in the Early History of the Earth

Differences in the isotopic ratios of xenon in the Earth's atmosphere and in the Richardson meteorite are discussed. The differences indicate that at least 10% of the atmospheric xenon-138 is fissiogenic. This is much greater than that expected from the uranium-238 spontaneous fission alone but can be explained as due to the spontaneous fission of some of the extinct trans-uranium elements and/or the induced fission of uranium-235 in the early history of the Earth. Published data on the terrestnial abundance of variOus isotopes and mass-yield curves of uranium-238 from spontaneous fission, uranium-235 from neutron-induced fission, and curium-242 from spontaneous fission are discussed. Differences in the isotopic ratios of xenon in the Earth's atmosphere and the cosmic abundance ratios for xenon isotopes are also considered. (C.H.)
Statins and cancer: a case of meta-uncertainty

Statins, a class of molecules that inhibit 3-hydroxy3-methylglutaryl CoA reductase, have revolutionized the management of hypercholesterolemia (1). Statins reduce low-density lipoprotein (LDL) cholesterol levels by 20% to 55% (2), decrease the progression of coronary lesions in angiographic studies, and reduce cardiovascular and total mortality (3,4). Short-term side effects, mainly liver dysfunction and myopathy, are uncommon and resolve after drug discontinuation. Subacute or chronic side effects, particularly if they are infrequent, are more difficult to detect in clinical trials. However, with more than 8% of adult patients in some general practices taking statins (5) and with estimates of as many as 26 million Americans qualifying for long-term cholesterol-lowering therapy (6), any serious side effect of statins, even if infrequent, becomes a public health concern. Concerns about the long-term safety of statins were originally raised by a review of the carcinogenicity of lipid-lowering drugs in animal studies (7). Statins are not mutagenic, but they increase the frequency of several cancers in rodents at levels of exposure similar to those in humans. Other studies, however, suggest that statins have an inhibitory effect on cancer proliferation (8,9). The results of animal and mechanistic studies are difficult to extrapolate to humans, but they cannot be dismissed. At a minimum, they require us to look hard for such effects in human populations. In this issue of the Journal, Bjerre and LeLorier (10) perform a meta-analysis of five large randomized trials of statins (11‐15) and conclude that neither cancer incidence nor mortality was increased in patients taking statins compared with patients taking placebo. They acknowledge that for the cancer endpoint, the follow-up of these trials was short (about 5 years), and they call for continued assessment in studies with longer follow-up. The two relevant questions are these: does this meta-analysis provide a fair summary of the evidence? And what should we do in the face of such evidence? Meta-analysis (16), a research technique with substantial power and peril, often provokes strong reactions, from keen promoters to those who deride it as “statistical alchemy.” One of the merits of the systematic approach