cssi/SciSciGPT-SciSciNet huggingface dataset:
A Web architecture to support the tailoring of training content and learner assessment

Instructional systems designers can face a difficult task with training development including curriculum content delivery method, and learner assessment. This situation becomes more complex when multiple types of learners must be trained with overlapping but not completely similar content. This paper discusses a flexible Web-based architecture that supports the tailoring of training content and learner assessment. The architecture supports the creation of multiple training treatments and assessments, and learner performance data collection.
Preparation, magnetic moments, infra-red and optical spectra of ortho-, meta-, and para- aminobenzenesulfonate copper(II) complexes

Abstract Reaction of o -, m -, and p -aminobenzenesulfonate salts (=o-L, m-L, p-L) with copper(II) perchlorate yields the crystalline complexes Cu(o-L) 2 , Cu(m-L) 2 , and Cu(p-L) 2 ·4H 2 O. Electron paramagnetic resonance and diffuse reflectance measurements of the complexes in aqueous solutions indicate that the Cu(II) is only oxygen bonded. For the solid o-L and m-L bis -complexes the infra-red spectra demonstrate that both the -NH 2 and -SO 3 − groups are involved in coordination, while in the hydrated solid p-L bis -complex only the -NH 2 group appears to be metal bonded. Optical diffuse reflectance and magnetic moment measurements on the solid compounds indicate that the anhydrous and hydrated isomeric bis -complexes are six-coordinate with an essentially octahedral configuration.
Liquid Crystalline Calixarenes

Bowl-shaped (bowlic) liquid crystals are reviewed and new bowlic materials containing rigid tungsten-oxo calix[4]arene based cores are discussed. Tungsten-oxo calix[4]arenes with 8 and 12 dodecyloxy sidechains have been investigated and exhibit bowlic columnar phases which are stable over approximately a 200° temperature range. The uncomplexed tetra-phenol ligands display only a transient liquid crystallinity on the first heating, and the conformational rigidity provided through tungsten-oxo complexation is necessary for well behaved mesomorphism. For the 8 sidechain analog the clearing point is at 320°C and the addition of four more sidechains results in a lower clearing point at 267°C. Polarized optical microscopy and DSC indicate that the 12 sidechain analog displays a phase with the columns packed in a hexagonal lattice which is conductive to the formation of polar phases. Both complexes exhibit a pronounced tendency to bind Lewis base guests in their cavities, and DMF forms very strong complexes which were spectroscopically characterized. The DMF guest produces large effects on the phase behavior by suppressing mesomorphism and lowering the isotropic points by 115°C and 84°C for the 8 and 12 sidechain compounds respectively. This extreme sensitivity to the DMF guest is conclusive proof that bowlic tungsten-oxo calix[4]arene liquid crystals organize in head-to-tail structures.
The mechanical properties of soft tissues—I: A mechanical system for bi-axial testing

A closed loop, microprocessor based, bi-axial, mechanical testing device for soft biological tissues is described. The device may be used for in vitro experiments with cylindrical specimens, such as arteries, or planar specimens such as skin and pericardium. The mechanical test is defined in software. Thus a variety of experiments can be run subject only to the limitations of the hardware. Two examples, illustrating the use of the instrumentation, are given. Rates of stretch of up to 7.5 ± 0.001 cm s−1 can be achieved. Position accuracy is ± 2.54 μ. Dimensions are measured 500 times per second (typical) without contacting the specimen.
Elastic-wave Reverse-time Migration With a Wavefield-separation Imaging Condition

Elastic-wave reverse-time migration (ERTM) is the most promising tool for true-amplitude and high-resolution migration in complex regions. However, conventional imaging conditions used in ERTM have two major drawbacks that result in severe image artifacts. One is caused by the conventional imaging of the full waves and another is caused by the polarizations between P and S waves. We introduce a new ERTM scheme to eliminate these drawbacks. It is based on the separation of wavefields with respect to a given direction. The separation is achieved after the elastic wavefields are downward continued into a target imaging region. The new ERTM does not make any assumption on elastic wave propagation, neither does it utilize a post-processing filtering on migration images. The separation of the wavefields is carried out using an approach for separation of VSP upgoing/downgoing wavefields. Synthetic imaging examples demonstrate that our ERTM scheme can effectively eliminate image artifacts of conventional reverse-time migration methods.
Progress-Report on researches in terrestrial magnetism and electricity at Department of Terrestrial Magnetism, Carnegie Institution of Washington, for year April 1937 to March 1938

The year has been marked by energetic prosecution of experimental investigation and continued coordination and integration of various researches paving the way for more general formulation of geophysical facts. Good progress has been made in two major projects which open new fields of investigation and promise important advances. Atomic-Physics Observatory—One of these is the completion of the Atomic-Physics Observatory and the considerable progress in the installation of the electrical equipment. The electrostatic generator and tube are designed to operate at potentials exceeding five million volts and offer unique opportunity for further studies in the expanding field of nuclear physics—a field to which we must look for additional understanding of magnetic phenomena.
Attenuation of early airway obstruction by mesenchymal stem cells in a murine model of heterotopic tracheal transplantation

Background Long-term success in lung transplantation is limited by obliterative bronchiolitis (OB). Presently, complete understanding of the mechanisms of OB has been elusive. Bone marrow–derived mesenchymal stem cells (MSC) have been shown to modulate repair of the injured lung in multiple disease models. We hypothesized that the injection of MSC would prevent development of early airway obstruction (AO) in the heterotopic tracheal transplant model. Methods Forty-four tracheas from BALB/c and C57BL/6 donors were transplanted into 22 C57BL/6 recipients. At the time of transplant, 13 of the allogeneic recipient mice were injected with 5 × 10 5 MSC from various murine sources. To confirm the role of the immune response in the generation of AO we used a permeable inhibitor of nuclear factor-kappaB (NF-κB) in 11 recipients after transplantation with 22 BALB/c tracheas. Results After transplantation, administration of MSC inhibited intraluminal obstruction by collagen in 98% of the mice and transforming factor-beta (TGF-β) expression decreased to levels similar to those observed in isograft controls. These effects were associated with a significant ( p Conclusion Our observations suggest that administration of MSC prevents development of airway occlusion in a mouse model, probably through the modulated immune response altering TGF-β expression.
Positive solutions for large elliptic systems of interacting species groups by cone index methods

Abstract This article considers the existence of positive solutions for various systems of four nonlinear coupled elliptic partial differential equations subjected to zero Dirichlet boundary conditions. In applications, the components can be interpreted as concentrations of four interacting populations or chemicals. The species are divided into two groups which interact in prey-predator or cooperating Volterra–Lotka type of relations. Within each group, the species can interact in other possibilities. Topological cone index method is used for proving the existence of positive coexistence solutions. Sufficient conditions are found in terms of the signs of the principal eigenvalues of various simple related operators.
Tracking the tissue distribution of marker dye following intranasal delivery in mice and chinchillas: a multifactorial analysis of parameters affecting nasal retention

The combined mucosal surface area is vast and represents the primary site of entry of most pathogens to the respiratory, gastrointestinal (GI), and urogenital tracts. It is recognized that vaccines delivered parenterally typically only induce weak mucosal immune responses and that by targeting the mucosal immune system protective antibodies and effector lymphocytes could be induced at the primary site of infection. In the present study, we have evaluated an extensive set of conditions required to ensure maximum retention of intranasally administered substances within the nasal cavity in the chinchilla and murine hosts. We report here that many parameters, such as anaesthesia, position of animal during and post delivery, and dosing schedule, must be optimized in concert with each other and that results from one species cannot be extrapolated directly to another animal model.
Antifungal activity of the termite alkaloid norharmane against the mycelial growth of Metarhizium anisopliae and Aspergillus nomius.

Abstract Antifungal activity of norharmane, a β-carboline alkaloid found in termites (Isoptera, Rhinotermitidae) was tested against two entomopathogenic fungi, Metarhizium anisopliae and Aspergillus nomius. It was determined that, at physiological concentration (10 μg ml−1), norharmane had no significant effect on A. nomius mycelial growth rate but reduced M. anisopliae growth rate by 11.9%. Contrary to previous findings, we suggest that norharmane has a limited role in disease resistance against fungal pathogens in individual subterranean termites, and we discuss the potential role of this chemical at a colony level.
Coronary perfusion pressure during cardiopulmonary resuscitation

Currently, there is no way to measure the effectiveness of cardiopulmonary resuscitation in humans. The literature suggests that minimum aortic diastolic and estimated coronary perfusion pressures during cardiopulmonary resuscitation (CPR) in the animal model correlate with higher resuscitation rates. Six patients were studied during CPR to determine the arterial diastolic and estimated coronary perfusion pressures (arterial minus right atrial diastolic pressures). Mean arterial pressures were 27/11 mm Hg, central venous pressures were 32/10 mm Hg, and the mean estimated coronary perfusion pressure was only 1 mm Hg. None of the six patients survived. This study demonstrates that the techniques of measuring hemodynamic values during CPR is practical. Poor estimated coronary perfusion pressures were obtained from the six patients studied. This study should be extended to include a large number of patients to determine whether these hemodynamic parameters can be used as prognostic indicators of successful resuscitation in humans.
A molecular rotor as viscosity sensor in aqueous colloid solutions.

Background Molecular rotors exhibit viscosity-dependent quantum yield, allowing non-mechanical determination of fluid viscosity. We analyzed fluorescence in the presence of viscosity-modulating macromolecules several orders of magnitude larger than the rotor molecule. Method of approach Fluorescence of aqueous starch solutions with a molecular rotor in solution was related to viscosity obtained in a cone-and-plate viscometer. Results In dextran solutions, emission intensity was found to follow a power-law relationship with viscosity. Fluorescence in hydroxyethylstarch solutions showed biexponential behavior with different exponents at viscosities above and below 1.5 mPa s. Quantum yield was generally higher in hydroxyethylstarch than in dextran solutions. The power-law relationship was used to backcalculate viscosity from intensity with an average precision of 2.2% (range of -5.5% to 5.1%). Conclusions This study indicates that hydrophilic molecular rotors are suitable as colloid solution viscosity probes after colloid-dependent calibration.
Enzymatic formation and chemical synthesis of an active metabolite of 3β-hydroxy-5α-cholest-8(14)-en-15-one, a potent regulator of cholesterol metabolism

The enzymatic (rat liver mitochondria) conversion of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one to 5 alpha-cholest-8(14)-ene-3 beta,26-diol-15-one is described. The enzymatic product was judged, on the basis of IH and 13C NMR studies, to be a 4:1 mixture of its 25R and 25S isomers. (25R)-5 alpha-Cholest-8(14)-ene-3 beta,26-diol-15-one was prepared through a five-step synthesis from (25R)-26-hydroxycholesterol. The (25R) isomer of the new compound was found to be highly active in the suppression of the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in cultured mammalian cells and to inhibit the esterification of cholesterol in jejunal microsomes.
Dynamic Cyclic Thiodepsipeptide Libraries from Thiol-Thioester Exchange

Thiol−thioester exchange was found to readily generate libraries of cyclic thiodepsipeptides under thermodynamic control, which will enable their use in a variety of dynamic combinatorial chemistry assays. The kinetic determinants of macrocycle formation and the role of amino acid structure on the reaction dynamics are discussed.
Economic Analysis, Environmental Policy, and Intergenerational Justice in the Reagan Administration The Case of the Montreal Protocol

Economic arguments played a significant role in the decision by the Reagan Administration to lead the international effort to protect the stratospheric ozone layer from depletion caused by certain otherwise useful industrial chemicals. During the period prior to the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987, it was recognized within the Administration that ethical considerations (involving the valuation of risk and intergenerational equity) were essential components of the economic analysis. Adoption of a principle of intergenerational neutrality had the consequence that any reasonable comparison of the benefits of ozone layer protection to the costs of regulatory control overwhelmingly favored regulation.
Early Intervention with Gifted Children A National Survey

This study surveyed the status of preschool and kindergarten programs for gifted children in 50 states, 5 territories and Washington, D.C. We received responses from 100% of the states, 40% of the ...
Obliqueness effects in asymptotic cross-sectional analysis of composite beams

Abstract Cross-sectional stiffness properties for general composite beams, along with the interior solution for warping, are derived in such a way as to provide the extra freedom to choose a cross-sectional plane that is not perpendicular to the local beam reference line. The present development treats prismatic as well as initially twisted and curved beams. The main purpose of allowing such a choice of coordinate systems is for the convenience of the analyst; one, of course, should not expect the final 3D results to change. The 3D strain field is derived for the corresponding nonorthogonal curvilinear set of coordinates which describe the undeformed and the deformed geometry of the beam. The analysis is carried out based on the variational-asymptotic method which is used to determine the warping field. For the development of the solution, it is shown that there is a fundamental difference between the solutions for a prismatic beam and a beam with initial twist and curvature, which in turn produces a limitation of the angle of obliqueness: the effect of obliqueness is treated exactly for a prismatic beam, while for the initially twisted and curved beam the obliqueness is regarded as a small parameter. The ultimate goal of the analysis is the determination of the cross-sectional stiffness matrix, which can then be used as input for the 1D problem. Then, using the recovering relations, one can recover the strain field over the entire cross section, once the previous problem has been solved. The validity of the method is demonstrated by recovery of accurate cross-sectional stiffnesses associated with a normal cross-sectional plane from those associated with an oblique cross-sectional plane, using a simple rotation-of-axes transformation.
A first order method of hydrate equilibrium estimation and its use with new structures

Abstract First order correlations are presented for phase equilibria of two clathrate hydrates which have been known for the last half century. The correlations are shown to apply to equilibria for a hydrate discovered in 1987. Extrapolations to newer, relatively unknown hydrates (which have been found only with unusual guests) suggest equilibrium conditions for hydrocarbon components.
A comprehensive evaluation of commonly used accelerometer energy expenditure and MET prediction equations

Numerous accelerometers and prediction methods are used to estimate energy expenditure (EE). Validation studies have been limited to small sample sizes in which participants complete a narrow range of activities and typically validate only one or two prediction models for one particular accelerometer. The purpose of this study was to evaluate the validity of nine published and two proprietary EE prediction equations for three different accelerometers. Two hundred and seventy-seven participants completed an average of six treadmill (TRD) (1.34, 1.56, 2.23 ms−1 each at 0 and 3% grade) and five self-paced activities of daily living (ADLs). EE estimates were compared with indirect calorimetry. Accelerometers were worn while EE was measured using a portable metabolic unit. To estimate EE, 4 ActiGraph prediction models were used, 5 Actical models, and 2 RT3 proprietary models. Across all activities, each equation underestimated EE (bias −0.1 to −1.4 METs and −0.5 to −1.3 kcal, respectively). For ADLs EE was underestimated by all prediction models (bias −0.2 to −2.0 and −0.2 to −2.8, respectively), while TRD activities were underestimated by seven equations, and overestimated by four equations (bias −0.8 to 0.2 METs and −0.4 to 0.5 kcal, respectively). Misclassification rates ranged from 21.7 (95% CI 20.4, 24.2%) to 34.3% (95% CI 32.3, 36.3%), with vigorous intensity activities being most often misclassified. Prediction equations did not yield accurate point estimates of EE across a broad range of activities nor were they accurate at classifying activities across a range of intensities (light <3 METs, moderate 3–5.99 METs, vigorous ≥6 METs). Current prediction techniques have many limitations when translating accelerometer counts to EE.
Dynamic SPECT imaging after injection of the benzodiazepine receptor ligand [123I]iomazenil in healthy human subjects

Previous work suggests that iomazenil (formerly known as Ro 16-0154) is a useful ligand for static imaging of the benzodiazepine (BZ) receptor with single photon emission computed tomography (SPECT). The present study evaluated the feasibility of dynamic SPECT imaging of cerebral radioactivity following intravenous [123I]iomazenil injection in healthy human subjects, in preparation for future receptor quantitation studies. Maximal brain uptake was reached approximately 25-30 minutes after i.v. administration of the radioligand and represented approximately 12% of the injected dose. The regional distribution of radioactive densities was consistent with the known distribution of BZ receptors in human brain, with highest uptake localized over the occipital area. Washout of cortical radioactivity was regionally variable but relatively slow, with a half-life of approximately 4 hours after the time of peak radioactivity. In summary, [123I]iomazenil is a promising SPECT radioligand for the BZ receptor, with high brain uptake, relatively slow washout of radioactivity, and appropriate regional distribution.
Exact complex source point beam expansion of electromagnetic fields from arbitrary closed surfaces

In this paper, a relatively simple, exact method is developed to expand any arbitrary and fully vector EM field into a continuum of CSP beams. In practice, the continuum must be appropriately discretized to obtain a convergent sum of CSP beams. Furthermore, the natural windowing property of the beam function can be advantageously used to truncate this beam set since only a small number of beams remain significant at a given observation point. Hence, this CSP beam expansion approach can be potentially very useful for solving a variety of EM problems including radiation in the presence of radomes, reflector systems, etc., radiation from curved apertures and the near field to far field transformation in near field measurements.
Soil Thermal and Ecological Impacts of Rain on Snow Events in the Circumpolar Arctic

Rain on snow (ROS) events are rare in most parts of the circumpolar Arctic, but have been shown to have great impact on soil surface temperatures and serve as triggers for avalanches in the midlatitudes, and they have been implicated in catastrophic die-offs of ungulates. The study of ROS is inherently challenging due to the difficulty of both measuring rain and snow in the Arctic and representing ROS events in numerical weather predictions and climate models. In this paper these challenges are addressed, and the occurrence of these events is characterized across the Arctic. Incidents of ROS in Canadian meteorological station data and in the 40-yr ECMWF Re-Analysis (ERA-40) are compared to evaluate the suitability of these datasets for characterizing ROS. The ERA-40 adequately represents the large-scale synoptic fields of ROS, but too often has a tendency toward drizzle. Using the ERA-40, a climatology of ROS events is created for thresholds that impact ungulate populations and permafrost. It is found that ROS events with the potential to harm ungulate mammals are widespread, but the large events required to impact permafrost are limited to the coastal margins of Beringia and the island of Svalbard. The synoptic conditions that led to ROS events on Banks Island in October of 2003, which killed an estimated 20 000 musk oxen, and on Svalbard, which led to significant permafrost warming in December of 1995, are examined. Compositing analyses are used to show the prevailing synoptic conditions that lead to ROS in four disparate parts of the Arctic. Analysis of ROS in the daily output of a fully coupled GCM under a future climate change scenario finds an increase in the frequency and areal extent of these events for many parts of the Arctic over the next 50 yr and that expanded regions of permafrost become vulnerable to ROS.
Evaluation of 227 Drugs for In Vitro Inhibition of Cytochrome P450 2B6

Cytochrome P450 2B6 (CYP2B6) is involved in the metabolism of drugs such as bupropion, efavirenz, propofol, and selegiline, among others. More than 200 commonly prescribed drugs and other xenobiotics were examined for their ability to inhibit CYP2B6-mediated bupropion hydroxylase activity. Thirty compounds were found exhibiting greater than 50% inhibition at 30 microM. Inhibitors of CYP2B6 were identified from a wide variety of therapeutic classes. The 2 platelet aggregation inhibitors, clopidogrel and ticlopidine, were both identified as potent inhibitors (IC50 = 0.0206 and 0.149 microM, respectively). Other inhibitors (IC50 < 1 microM) included clotrimazole, itraconazole, sertraline, and raloxifene. These in vitro data were used along with clinical pharmacokinetic information in the prediction of potential drug-drug interactions that could occur by inhibition of CYP2B6. Although few drugs tested are expected to cause drug interactions, clopidogrel and ticlopidine were identified as being of concern as potential inhibitors of clinical relevance. These findings are discussed in context to potential drug interactions that could be observed between these agents and drugs for which CYP2B6 is involved in metabolism.
General principles in the community ecology of ectomycorrhizal fungi

Knowledge of the factors that determine ectomycorrhizal fungal community structure is essential in many areas of practical significance including conservation, habitat restoration, prevention or amelioration of species invasions, and the prediction of responses to climate change. With respect to these goals, however, community ecology, in general, and ectomycorrhizal fungal community ecology, in particular, have been rather disappointing. Indeed, some feel that community ecology is, at best, an esoteric discipline and, at worst, an inane one. But there is hope. As we apply what has been learned about other organisms concerning the relationships between functional traits and success (abundance), it may be possible to elucidate general principles that govern much of the structuring of ectomycorrhizal fungal communities. A hierarchical model of ectomycorrhizal fungal community structure is presented that involves abiotic filtering of immigrant propagules based on functional traits, followed by interspecific competition as ameliorated by disturbance and habitat partitioning, the outcomes of which are dependent on functional traits.
Cross‐subject comparison of principal diffusion direction maps

Diffusion tensor imaging (DTI) data differ fundamentally from most brain imaging data in that values at each voxel are not scalars but 3 × 3 positive definite matrices also called diffusion tensors. Frequently, investigators simplify the data analysis by reducing the tensor to a scalar, such as fractional anisotropy (FA). New statistical methods are needed for analyzing vector and tensor valued imaging data. A statistical model is proposed for the principal eigenvector of the diffusion tensor based on the bipolar Watson distribution. Methods are presented for computing mean direction and dispersion of a sample of directions and for testing whether two samples of directions (e.g., same voxel across two groups of subjects) have the same mean. False discovery rate theory is used to identify voxels for which the two-sample test is significant. These methods are illustrated in a DTI data set collected to study reading ability. It is shown that comparison of directions reveals differences in gross anatomic structure that are invisible to FA.
Interaction of historical and nonhistorical disturbances maintains native plant communities

Historical disturbance regimes are often considered a critical element in maintaining native plant communities. However, the response of plant communities to disturbance may be fundamentally altered as a consequence of invasive plants, climate change, or prior disturbances. The appropriateness of historical disturbance patterns under modern conditions and the interactions among disturbances are issues that ecologists must address to protect and restore native plant communities. We evaluated the response of Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh plant communities to their historical disturbance regime compared to other disturbance regimes. The historical disturbance regime of these plant communities was periodic fires with minimal grazing by large herbivores. We also investigated the influence of prior disturbance (grazing) on the response of these communities to subsequent disturbance (burning). Treatments were: (1) ungrazed (livestock grazing excluded since 1936) and unburned, (2) grazed and unburned, (3) ungrazed and burned (burned in 1993), and (4) grazed and burned. The ungrazed-burned treatment emulated the historical disturbance regime. Vegetation cover, density, and biomass production were measured the 12th, 13th, and 14th year post-burning. Prior to burning the presence of Bromus tectorum L., an exotic annual grass, was minimal (,0.5% cover), and vegetation characteristics were similar between grazed and ungrazed treatments. However, litter accumulation was almost twofold greater in ungrazed than in grazed treatments. Long- term grazing exclusion followed by burning resulted in a substantial B. tectorum invasion, but burning the grazed areas did not produce an invasion. The ungrazed-burned treatment also had less perennial vegetation than other treatments. The accumulation of litter (fuel) in ungrazed treatments may have resulted in greater fire-induced mortality of perennial vegetation in ungrazed compared to grazed treatments. Our results demonstrate that prior disturbances exert a strong influence on the response of plant communities to subsequent disturbances and suggest that low-severity disturbances may be needed in some plant communities to increase their resilience to more severe disturbances. Modern deviations from historical conditions can alter ecosystem response to disturbances, thus restoring the historical disturbance regime may not be an appropriate strategy for all ecosystems.
Single-Molecule Kinetics of λ Exonuclease Reveal Base Dependence and Dynamic Disorder

We used a multiplexed approach based on flow-stretched DNA to monitor the enzymatic digestion of λ-phage DNA by individual bacteriophage λ exonuclease molecules. Statistical analyses of multiple single-molecule trajectories observed simultaneously reveal that the catalytic rate is dependent on the local base content of the substrate DNA. By relating single-molecule kinetics to the free energies of hydrogen bonding and base stacking, we establish that the melting of a base from the DNA is the rate-limiting step in the catalytic cycle. The catalytic rate also exhibits large fluctuations independent of the sequence, which we attribute to conformational changes of the enzyme-DNA complex.
Controllably degradable β-sheet nanofibers and gels from self-assembling depsipeptides

Self-assembled peptide materials have received considerable interest for a range of applications, including 3D cell culture, tissue engineering, and the delivery of cells and drugs. One challenge in applying such materials within these areas has been the extreme stability of β-sheet fibrillized peptides, which are resistant to proteolysis, degradation, and turnover in biological environments. In this study, we designed self-assembling depsipeptides containing ester bonds within the peptide backbone. Beta-sheet fibrillized nanofibers were formed in physiologic conditions, and two of these nanofiber-forming depsipeptides produced hydrogels that degraded controllably over the course of days-to-weeks via ester hydrolysis. With HPLC, TEM, and oscillating rheometry, we show that the rate of hydrolysis can be controlled in a straightforward manner by specifying the amino acid residues surrounding the ester bond. In 3D cell cultures, depsipeptide gels softened over the course of several days and permitted considerably more proliferation and spreading of C3H10T1/2 pluripotent stem cells than non-degradable analogs. This approach now provides a reliable and reproducible means to soften or clear β-sheet fibrillized peptide materials from biological environments.
A parallel hashed oct-tree N-body algorithm

The authors report on an efficient adaptive N-body method which we have recently designed and implemented. The algorithm computes the forces on an arbitrary distribution of bodies in a time which scales as N log N with the particle number. The accuracy of the force calculations is analytically bounded, and can be adjusted via a user defined parameter between a few percent relative accuracy, down to machine arithmetic accuracy. Instead of using pointers to indicate the topology of the tree, the authors identify each possible cell with a key. The mapping of keys into memory locations is achieved via a hash table. This allows the program to access data in an efficient manner across multiple processors. Performance of the parallel program is measured on the 512 processor Intel Touchstone Delta system. Comments on a number of wide-ranging applications which can benefit from application of this type of algorithm are included.
Optimal parameter updating for optical diffusion imaging

Because optical diffusion imaging is a highly nonlinear inverse problem, iterative inversion algorithms based on the Born approximation have usually been employed as reconstruction technique, but convergence is slow, especially for high contrast parameter distributions. We show here that the slow convergence of the conventional algorithms is due to the linear integral operator derived by the Born approximation not being the optimal Frechet derivative. We derive the optimal Frechet derivative operator with respect to the spatially varying absorption and scattering coefficients in integral form, and then develop a new iterative inversion algorithm.
The Russian Church and Its Future

Examines Russian Orthodoxy, focusing on its historical background, religious ethos, institutionalization and dogmatic affirmation. Evaluates the record of the Russian Church during the Communist period and speculates about its future. Cites the limitations of Russian Orthodoxy in performing the “priestly” and “prophetic” functions. Finally, given the similarities of Russian Orthodoxy and Roman Catholicism, recommends “Uniate option” for the contemporary Russian Church. Suggests that such an option would strengthen Russian Orthodoxy and compensate for those factors that made it so ineffective during the Marxist‐Leninist period.
Effect on cutting force in turning hardened tool steels with cubic boron nitride inserts

Abstract Numerical simulations of high-speed orthogonal machining were performed to study the finish hard-turning process as a function of cutting speed, feed, cutter geometry, and workpiece hardness. In the simulations, properties representative of AISI 52100 bearing steel, AISI H13 hot work tool steel, AISI D2 cold work steel, and AISI 4340 low alloy steel were assumed for the workpiece. Cubic boron nitride (CBN) or polycrystalline (PCBN) inserts are widely used as cutting tool material in such high-speed machining of hardened tool steels—due to high hardness, high abrasive wear resistance, and chemical stability at high temperature. Cutting forces and feed forces were determined in the numerical simulations. Among process parameters, cutter geometry and workpiece hardness, the feed has the most significant effect on cutting and feed forces. With same cutting conditions, turning AISI 4340 gets the highest cutting force while turning AISIS 52100 has the highest feed force and turning AISI D2 gets the lowest cutting force and feed force. The feed force appears to be a larger force component than the cutting force in the hard turning. Cutting force and feed force increase with increasing feed, tool edge radius, negative rake angle, and workpiece hardness. Results from simulations are compared to experimental results reported in the literature.
Doctoral Colloquium Keynote Address Conduct, Misconduct, And Cargo Cult Science

In the South Seas there is a cargo cult of people. During the war they saw airplanes land with lots of good materials, and they want the same thing to happen now. So they’ve arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head like headphones and bars of bamboo sticking out like antennas-he’s the controller-and they wait for the airplanes to land. They’re doing everything right. The form is perfect. It looks exactly the way it looked before. But it doesn’t work. No airplanes land. So I call these things cargo cult science, becauw they follow all the apparent precepts and forms of scientific investigation, but they’re missing something essential, because the planes don’t land. Now it behooves me, of course, to tell you what they’re missing. . . . It’s a kind of scientific integrity, a principle of scientific thought that corresponds to a kind of utter honesty-a kind of leaning over backwards. For example, if you’re doing an experiment, you should report everything that you think might make it invalid-not only what you think is right about, it: other causes that could possibly explain your results; and things you thought of that you’ve eliminated by some other experiment, and how they worked-to make sure the other fellow ca:n tell they have been eliminated.
Water Retention by Cotton Fabric During Centrifuging

A study has been made of the parameters affecting the retention of liquid water by cotton fabric during centrifugal extraction. In addition to the obvious effect of centrifugal field strength, data...
FundExplorer: supporting the diversification of mutual fund portfolios using context treemaps

An equity mutual fund is a financial instrument that invests in a set of stocks. Any two different funds may partially invest in some of the same stocks, thus overlap is common. Portfolio diversification aims at spreading an investment over many different stocks in search of greater returns. Helping people with portfolio diversification is challenging because it requires informing them about both their current portfolio of stocks held through funds and the other stocks in the market not invested in yet. Current stock/fund visualization systems either waste screen real estate and visualization of all data points. We have developed a system called FundExplorer that implements a distorted treemap to visualize both the amount of money invested in a person's fund portfolio and the context of remaining market stocks. The FundExplorer system enables people to interactively explore diversification possibilities with their portfolios.
Phylogenetic diversity of marine coastal picoplankton 16s rRNA genes cloned from the continental shelf off Cape Hatteras, North Carolina

The phylogenetic diversity of a continental-shelf picoplankton community was examined by analyzing 16s ribosomal RNA (rRNA) genes amplified from environmental DNA with bacterial-specific primers and the polymerase chain reaction (PCR). Picoplankton populations collected from the pycnocline (10 m) over the eastern continental shelf of the United States near Cape Hatteras, North Carolina, served as the source of bulk nucleic acids used in this study. A large proportion of the 169 rDNA clones recovered (33%) were related to plastid 16s r-RNA genes, including plastids from both chromophyte and chlorophyte algae. Most bacterial gene clones (75% of bacterial clones, 50% of the total) were closely related to r-RNA gene lineages that had been discovered previously in clone libraries from opcnocean marine habitats, including the SARI36 cluster (y-Proteobacteria), SAR83, SARll, and SAR116 clusters (all a-Proteobacteria), as well as the marine Gram-positive cluster (high G+C Gram-positive). Most of the remaining bacterial clones recovered were phylogenetically related to the y and /3 subclasses of the Proteobacteria, including an rDNA lineage within the type 1 methylotroph clade of the p subclass. The abundance of plastid rDNAs and the lack of cyanobacterial-related clones, as well as the presence of P-Proteobacteria, are features of this coastal picoplankton gene clone library that distinguish it from similar studies of oligotrophic open-ocean sites. Overall, however, these data indicate that a limited number of as yet uncultured bacterioplankton lineages, related to those previously observed in the open ocean, can account for most cells in this coastal marine bacterioplankton assemblage.
Getting nutrition education into medical schools: a computer-based approach

Despite awareness of the importance of nutrition as part of medical student's education, numerous barriers exist to incorporating nutrition education into the medical school curriculum. Chief among such barriers is that most medical schools do not have faculty trained specifically in nutrition. A curriculum is needed that can deliver comprehensive nutrition information that is consistent across medical schools. One way to deliver this information is to use computer-assisted instruction (CAI). To meet the different needs of medical schools and provide a consistent base of nutrition information, we developed a series of interactive, multimedia educational programs (Nutrition in Medicine) that teach the basic principles of nutritional science and apply those principles in a case-oriented approach. Curriculum content is derived from the American Society for Clinical Nutrition consensus guidelines. These modules offer the advantages of accessibility, self-paced study, interactivity, immediate feedback, and tracking of student performance. Modules are distributed free to all US medical schools. Preliminary data from surveys gathered by our team at the University of North Carolina at Chapel Hill indicate that 73 US medical schools use, or are planning to use, these modules; more schools are currently evaluating the programs. Successful implementation of CAI requires easy program access, faculty training, adequate technical support, and faculty commitment to the programs as a valuable resource. CAI fails when the program is just placed in the library and students are told to use it when they can find the time.
Clostridium Novyi Isolated from Chickens

Abstract Over the past two years, there has been encountered a number of pathological conditions in chickens characterized by lameness, all outbreaks being in broiler-type replacement birds. Apparently most, if not all cases, have been in one sex, male or female these originating in replacement flocks from different genetic sources. The age incidence has varied from approximately 10 to 30 weeks. The morbidity is usually in the range of less than one to about five percent, but in cases has been as high as 50 percent. Mortality appears to be related to the degree of recumberance. The course is prolonged. The severity of lameness has varied from an obvious limp to complete incapacity of one or both legs. The hock joints show degrees of arthritis varying from slight to very severe with purulent exudate. Advanced cases show caseation. The subcutaneous tissue above the hock may be edematous or hemorrhagic with some…
The Ecological Significance of Leg Autotomy for Climbing Temperate Species of Harvestmen (Arachnida, Opiliones, Sclerosomatidae)

Abstract In encounters with predators, sclerosomatid harvestmen may employ a variety of defensive tactics including the voluntary detachment of legs (autotomy). The long-term costs of this evasive defense are not fully understood, but prior studies have documented negative consequences for terrestrial locomotion and foraging. In this study, we investigated the impact of leg loss upon locomotion in adult harvestmen (Leiobunum spp.). In southeastern Virginia, these harvestmen regularly climb vegetation and occupy perches on tree trunks, branches, and leaves that are often 1–2 m or more above the ground. In our study, we measured walking and climbing speeds for individuals with 5, 6, 7, and 8 legs. The results of our field surveys conducted over three seasons revealed relatively high frequencies (36–63%) of leg loss. We also found that individuals with six legs occupied perches that were significantly lower in the understory than those with eight legs. In the lab, we observed significantly slower walking spe...
Porcine zona pellucida: association of sperm receptor activity with the alpha-glycoprotein component of the Mr = 55,000 family

The immunogenicity and sperm receptor activity of five preparations of the major porcine zona pellucida glycoprotein family ZP3 (Mr = 55,000) were investigated. These included (1) ZP3, a chromatographically purified preparation of the 55,000 family; (2) ZP3 alpha, and (3) ZP3 beta, the two-component glycoproteins of the ZP3 family; (4) ZP3-EBGD, a partially deglycosylated preparation of ZP3 obtained by enzymatic treatment; and (5) ZP3-DG, a chemically deglycosylated preparation of ZP3. Titer studies using mouse and rabbit antisera prepared against each preparation yielded the following order of immunogenicity: ZP3 and ZP3 beta greater than ZP3-EBGD and ZP3 alpha greater than ZP3-DG, indicating that ZP3 becomes less immunogenic as more carbohydrate is removed. Pretreatment of intact zona with the various antisera prior to zona exposure to sperm resulted in an inhibition of sperm attachment to those zona treated with antibodies to ZP3, ZP3-EBGD, and ZP3 alpha. Pretreatment of zona with antibodies to ZP3 beta and ZP3-DG had no effect on sperm attachment. Studies involving pretreatment of boar sperm with the various ZP3 preparations prior to their use in a sperm-zona attachment assay and investigations involving displacement of the radiolabeled ZP3 preparations from sperm by unlabeled ZP3 preparations also yielded findings similar to the antibody studies. Collectively, these data indicate that ZP3 alpha probably functions as a zona receptor for boar sperm and that carbohydrate has an important role in maintaining the functional integrity of the ZP3 alpha glycoprotein.
THz Intersubband Lasers Using the Inverted Mass Scheme

We propose a novel intersubband laser based on the inverted-effective-mass feature of a valence subband in-plane dispersion. We consider GaAs/AlGaAs QW structures which give rise to several confined subbands including ground state heavy-hole subband (HH1) and light-hole subband (LH1). The inverted-effective-mass feature in subband LH1 emerges only in wide QW structures which produce closely spaced subbands in energy that are strongly coupled. The energy separation between subbands LH1 and HH1 is typically below the optical phonon energy in the THz range. Laser wavelength determined by this energy separation is 62μm for a well width of 70A. Our calculation shows that with only a small fraction of the carrier population in the upper subband (LH1), it is still possible to achieve population inversion between the two subbands locally in k-space where the light-hole effective mass is inverted. Our result indicates that optical gain in excess of 150/cm can be achieved with a relatively small pumping current density on the order of 100 A /cm 2.
Temporal and Seasonal Trends in Streamflow in the Uinta Mountains, Northeastern Utah, and Relation to Climatic Fluctuations

Over the past half century there has been a trend in numerous regions of the western United States toward a declining portion of the total annual streamflow occurring during the snowmelt season (April through July). Changes in the seasonality of discharge primarily reflect a shift in the seasonal distribution of precipitation. Years with an unusually large fraction of annual streamflow occurring during the spring snowmelt coincide with winters with unusually high precipitation. Years with an unusually small fraction of annual streamflow occurring during the spring snowmelt coincide with unusually low precipitation during the winter and unusually warm temperatures during the spring. The magnitude of the peak annual flood is sensitive to amount of winter precipitation and variations in spring and early summer temperatures. Large peak annual floods occur in years with high precipitation and low temperatures in the late winter and spring, which preserve the maximum snowpack. Small peak annual floods occur in years with low precipitation throughout the winter and high temperatures in the spring. During the period of gage record, peak annual flood magnitudes exhibit temporal variability. Extreme events in the peak annual flood record, particularly years of large snowmelt floods, have increased in frequency since 1960. Large floods during this time period occur in years with atypically cool temperatures in April and May, which would likely preserve the winter snowpack through the spring.
Mission creep and marketing myopia: lessons learned from the business world

Purpose – This paper aims to provide insights and commentary into issues encountered in providing library resources and services in a rapidly changing environment with varied user expectations. Design/methodology/approach – This paper uses examples and illustrations from the business world to demonstrate the importance of having a clear mission and a thorough understanding of the needs and expectations of the population being served. Findings – Disruptive technology has had major impacts on many business sectors. Libraries can learn from the choices many of these businesses entities made to improve services and achieve greater returns on investment. Originality/value – This paper examines several widely recognizable business entities and the manners in which they chose to address disruptions caused by changes in the marketplace and in consumer attitudes. Libraries can use these illustrations to better position themselves to deal effectively with the inevitable change in the future.