cssi/SciSciGPT-SciSciNet huggingface dataset:
Children's use of iPads in outdoor environmental education programs

ABSTRACTThis exploratory study aimed to understand how use of digital technology, specifically iPads, impacts the learning experiences of children during outdoor environmental education programs. iPads were integrated into water quality education programs for fifth grade students from an urban area. Qualitative observations were analyzed to document students' attitudes, behaviors, and comprehension of material. The seven themes that emerged from the data—reaction to mobile devices, group interactions, nature prevails, digital natives versus digital immigrants, introduction of mobile devices, mobile devices in the hands of children, and instruments for learning—offer new insights into how children interact with nature while using digital technologies and suggest best practices for technology integration in environmental education.
Catalytic-Independent Functions of PARP-1 Determine Sox2 Pioneer Activity at Intractable Genomic Loci

Pioneer transcription factors (TFs) function as genomic first responders, binding to inaccessible regions of chromatin to promote enhancer formation. The mechanism by which pioneer TFs gain access to chromatin remains an important unanswered question. Here we show that PARP-1, a nucleosome-binding protein, cooperates with intrinsic properties of the pioneer TF Sox2 to facilitate its binding to intractable genomic loci in embryonic stem cells. These actions of PARP-1 occur independently of its poly(ADP-ribosyl) transferase activity. PARP-1-dependent Sox2-binding sites reside in euchromatic regions of the genome with relatively high nucleosome occupancy and low co-occupancy by other transcription factors. PARP-1 stabilizes Sox2 binding to nucleosomes at suboptimal sites through cooperative interactions on DNA. Our results define intrinsic and extrinsic features that determine Sox2 pioneer activity. The conditional pioneer activity observed with Sox2 at a subset of binding sites may be a key feature of other pioneer TFs operating at intractable genomic loci.
Shock wave interactions with liquid sheets

Shock wave interactions with a liquid sheet are investigated by impacting planar liquid sheets of varying thicknesses with a planar shock wave. A square frame was designed to hold a rectangular liquid sheet, with a thickness of 5 or 10 mm, using plastic membranes and cotton wires to maintain the planar shape and minimize bulge. The flat liquid sheet, consisting of either water or a cornstarch and water mixture, was suspended in the test section of a shock tube. Incident shock waves with Mach numbers of $$M_\mathrm{s} = 1.34$$ and 1.46 were considered. A schlieren technique with a high-speed camera was used to visualize the shock wave interaction with the liquid sheets. High-frequency pressure sensors were used to measure wave speed, overpressure, and impulse both upstream and downstream of the liquid sheet. Results showed that no transmitted shock wave could be observed through the liquid sheets, but compression waves induced by the shock-accelerated liquid coalesced into a shock wave farther downstream. A thicker liquid sheet resulted in a lower peak overpressure and impulse, and a cornstarch suspension sheet showed a higher attenuation factor compared to a water sheet.
Alkaline Peroxide Delignification of Corn Stover

Selective biomass fractionation into carbohydrates and lignin is a key challenge in the conversion of lignocellulosic biomass to fuels and chemicals. In the present study, alkaline hydrogen peroxide (AHP) pretreatment was investigated to fractionate lignin from polysaccharides in corn stover (CS), with a particular emphasis on the fate of the lignin for subsequent valorization. The influence of peroxide loading on delignification during AHP pretreatment was examined over the range of 30–500 mg H2O2/g dry CS at 50 °C for 3 h. Mass balances were conducted on the solid and liquid fractions generated after pretreatment for each of the three primary components, lignin, hemicellulose, and cellulose. AHP pretreatment at 250 mg H2O2/g dry CS resulted in the pretreated solids with more than 80% delignification consequently enriching the carbohydrate fraction to >90%. Two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy of the AHP pretreated residue shows that, under high peroxide loadings (>250 mg H2O2...
Using a Peer Confrontation System in a Group Setting.

The effectiveness of a peer confrontation system applied in a group setting was examined using a reversal design. Two groups of students with disabilities educated in a self-contained classroom wit...
Sensitivity of the Hydrogen Epoch of Reionization Array and its build-out stages to one-point statistics from redshifted 21 cm observations

We present a baseline sensitivity analysis of the Hydrogen Epoch of Reionization Array (HERA) and its build-out stages to one-point statistics (variance, skewness, and kurtosis) of redshifted 21 cm intensity fluctuation from the Epoch of Reionization (EoR) based on realistic mock observations. By developing a full-sky 21 cm lightcone model, taking into account the proper field of view and frequency bandwidth, utilising a realistic measurement scheme, and assuming perfect foreground removal, we show that HERA will be able to recover statistics of the sky model with high sensitivity by averaging over measurements from multiple fields. All build-out stages will be able to detect variance, while skewness and kurtosis should be detectable for HERA128 and larger. We identify sample variance as the limiting constraint of the variance measurement while skewness and kurtosis measurements will be primarily limited by thermal noise. The sensitivity can be improved by performing frequency binning and windowing. In addition, we find that strong sample variance fluctuation in the kurtosis measured from an individual field of observation indicates the present of outlying cold or hot regions in the underlying fluctuations, a feature that can potentially be used as an EoR bubble indicator. This manuscript is altered from the originally published paper to reflect corrections in the erratum.
Protein-Ligand Binding Studied by Amide Hydrogen Exchange and Mass Spectrometry

The rates at which hydrogens located at peptide amide linkages in proteins undergo isotopic exchange when proteins are incubated in D2O may be sensitive to their access to the aqueous solvent. If ligands shield the binding sites from the solvent, isotopic exchange of hydrogens located in the vicinity of the binding sites might be the basis of a method for locating ligand binding sites on proteins. Although successful applications of this approach have been reported, results of more recent studies indicate that structural changes occurring distant from the binding epitope may also change upon ligand binding, thus confounding interpretation of results. The suggestion is made here that isotopic exchange rates of a subset of amide hydrogens whose exchange rates depend primarily on the access of the amide hydrogens to the aqueous solvent might be more diagnostic for ligand binding sites. Fundamental mechanisms for amide hydrogen exchange and the protein fragmentation/mass spectrometry method for determining hydrogen exchange rates are reviewed with emphasis on kinetic measurements for determining isotopic exchange rate constants for the most rapidly exchanging peptide amide hydrogens in large proteins.
Metric techniques for maintenance programmers in a maintenance ticket environment

In the domain of software engineering, tracking metrics and evaluating developer performance has been a field of great interest. Project managers are constantly looking to understand the performance of their team, which can help plan for future projects as well as identify potential issues. While the development process has been the focus of many of these metrics over the years, there is a lack of understanding on how to best keep metrics and track performance on a maintenance team. Many organizations have two separate resource pools. One is dedicated to the development of new applications, while another is tasked at maintaining the current system. In software engineering industry, there are many metrics that can quantitatively measure the performance of a software developer, however there are few if any metrics geared towards the maintenance group. Because they are completely separate functions in the software world, this paper proposes a new metric technique to measure maintenance programmer's performance.
The Two-Dimensional World of 3He in 3He-4He Mixture Films

For thin films of 4 He at low temperatures the addition of sub-monolayer numbers of 3 He atoms results in the 3 He residing in a ground state at the free surface of the 4 He film. For low 3 He coverage the 3 He are a nearly ideal two-dimensional Fermi system. With increasing numbers of 3 He atoms the interactions among the 3 He increase. The results from a number of experiments that reveal the remarkable properties of this rich, interacting, two-dimensional 3 He system are described. These results include the magnetization, the energetics of the 3 He atoms in quantum states, the diffusion of the 3 He along the 4 He film, and the 3 He effective mass. The techniques employed include NMR, specific heat, quartz crystal microbalance and third sound. A clearer picture of the properties of the 3 He is now emerging, and preliminary numbers for the 3 He coverage dependence of the Fermi Liquid parameters are presented. Prospects for the observation of superfluidity of the 3 He in this system are discussed.
The Art of Culture War: (Un)Popular Culture, Freedom of Expression, and Art Education

This article examines the culture wars in the United States and considers their impact on the field of art education. Stretching across virtually ever facet of contemporary culture, these ideologic...
Relocation of Maternal-Fetal Medicine Specialists in the United States.

Objective To examine patterns in relocation of maternal–fetal medicine (MFM) specialists during the recent 10 years. Study Design This descriptive study analyzed the migration of MFM specialists between 2006 and 2016 based on county locations. Year-to-year comparisons of physicians in active clinical practice were performed. Demographic and county characteristics were gathered from three data resources. A multivariable logistic regression model was used to identify factors associated with relocation. Results An average of 7.4% (5.5–10.8%) of all 1,104 (1,103–1,115) MFM specialists moved per year. Approximately one in three (36%) relocated during the 10 years, usually once or twice. The likelihood of relocation was higher if the physician was younger, especially under 40 years compared with those aged 60 years and older (odds ratio [OR] = 2.08; 95% confidence interval [CI]: 1.36–3.19). No differences were noted based on gender and race/ethnicity. Physicians in independent group practices were more inclined to relocate, especially when compared with those in a solo or two-physician practice (OR = 0.38; 95% CI: 0.27–0.54). Relocations were primarily between urban counties (95.9%) and showed a significant regional pattern. Conclusion Approximately one in three MFM specialists relocated in the past 10 years, mostly between urban counties and especially in independent group practices.
Impacts of Federal Prevention Funding on Reported Gonorrhea and Chlamydia Rates.

Introduction The Centers for Disease Control and Prevention allocates funds annually to jurisdictions nationwide for sexually transmitted infection prevention activities. The objective of this study was to assess the effectiveness of federal sexually transmitted infection prevention funding for reducing rates of reported sexually transmitted infections. Methods In 2017–2018, finite distributed lag regression models were estimated to assess the impact of sexually transmitted infection prevention funding (in 2016 dollars per capita) on reported chlamydia rates from 2000 to 2016 and reported gonorrhea rates from 1981 to 2016. Including lagged funding measures allowed for assessing the impact of funding over time. Controls for state-level socioeconomic factors, such as poverty rates, were included. Results Results from the main model indicate that a 1% increase in annual funding would cumulatively decrease chlamydia and gonorrhea rates by 0.17% (p Conclusions The significant inverse associations between federal sexually transmitted infection prevention funding and rates of reported chlamydia and gonorrhea suggest that federally funded sexually transmitted infection prevention activities have a discernable effect on reducing the burden of sexually transmitted infections. The reported sexually transmitted infection rate in a given year depends more on prevention funding in previous years than on prevention funding in the current year, demonstrating the importance of accounting for lagged funding effects.
Accuracy of Dynamic Force Compensation Varies With Direction and Speed

This study investigates physical responses to force perturbations while tracking a moving target. The results show accuracy depends on the direction of a force perturbation and speed of the task, but generally not on hand. There are also differences in responses when the force is first applied and when it is removed.
Inconsistency and Incompleteness, Revisited

Graham Priest (In contradiction) introduces an informal but presumably rigorous and sharp ‘provability predicate’. He argues that this predicate yields inconsistencies, along the lines of the paradox of the Knower. One long-standing claim of Priest’s is that a dialetheist can have a complete, decidable, and yet sufficiently rich mathematical theory. After all, the incompleteness theorem is, in effect, that for any recursive theory A, if A is consistent, then A is incomplete. If the antecedent fails, as it might for a dialetheist, then the consequent may also fail to hold. One somewhat friendly purpose of my ‘Incompleteness and inconsistency’ was to improve the technical situation for the dialetheist, eschewing reliance on an informal provability predicate. Another, less friendly purpose was to bring out what I took to be some untoward consequences of the situation. It seems that Priest accepted at least some of the improvements that I attempted. In the second edition of In contradiction, he responded to the alleged untoward consequences. One purpose of this note is to revisit the technical and philosophical situation. There were some errors in my original presentation, brought out by discussion with Priest and by Hartry Field’s analysis of the second incompleteness theorem in such contexts. A second task here is to present a sort of Curry version of the Godel incompleteness situation. I tentatively conclude that even for a dialetheist, an interesting and complete theory is not as easy to come by as it may look—at least not for theories of arithmetic that are plausible for a dialetheist.
Monte Carlo simulation for improving spectral photoacoustic imaging-based oxygen saturation estimation of human placental tissue

Using spectral photoacoustic imaging (sPAI) to estimate oxygen saturation of tissue at depth suffers from inaccuracies due to the unknown optical absorption and scattering properties of tissue. Because of the high scattering and absorption of light by tissue, the estimation of concentrations of Hb and HbO2 from the measured photoacoustic (PA) signal intensity can be erroneous. Simulation of wavelength-dependent light transport in tissue can help to estimate the local fluence distribution within the tissue. In this work, a Monte Carlo simulation has been implemented to simulate the fluence distribution in placental tissue. We obtained sPAI images of ex vivo human placental tissue and demonstrate improved estimations of hemoglobin oxygen saturation by using a fluence correction derived from the Monte Carlo simulation. The results show that with simulation correction, the oxygen saturation value is 12.61±3% which is closer to the value 6.8% directly measured from ex vivo human placenta using invasive oxygen probe.
Evolution of viscoelastic coagulation testing.

The methods of viscoelastic coagulation testing (VCT) have evolved since the original invention of thrombelastography over 60 years ago, and new generations of devices are clinically used to guide ...
Autocatalytic behavior of trimethylindium during thermal decomposition

Pyrolysis of trimethylindium (TMIn) in a hot-wall flow-tube reactor has been investigated at temperatures between 573 and 723 K using a modulated molecular-beam mass-sampling technique and detailed numerical modeling. The TMIn was exposed to various mixtures of carrier gases: He, H{sub 2}, D{sub 2}, and C{sub 2}H{sub 4}, in an effort to elucidated the behavior exhibited by this compound in different chemical environments. The decomposition of TMIn is a heterogeneous, autocatalytic process with an induction period that is carrier-gas dependent and lasts on the order of minutes. After activation of the tube wall, the thermolysis exhibits a steady-state behavior that is surface mediated. This result is contrary to prior literature reports, which state that decomposition occurs in the gas phase via successive loss of the CH{sub 3} ligands. This finding also suggests that the bond dissociation energy for the (CH{sub 3}){sub 2}In-CH{sub 3} bond derived from flow-tube investigations is erroneous and should be reevaluated.
First-principles studies of defects, doping, and diffusion in gallium oxide (Conference Presentation)

We have used first-principles modeling, based on advanced hybrid functional calculations within density functional theory, to accurately predict properties of point defects and impurities in Ga2O3 and related materials. Point defects act as compensating centers, but they also assist diffusion of impurities. Accurate knowledge of formation energies and migration barriers then allows determining the doping profile. These results provide guidance for incorporating Ga2O3 into devices. Work performed in collaboration with J. Hwang, A. Janotti, J. L. Lyons, H. Peelaers, and J. B. Varley.
Surface topographical effects in the diffusion bonding of 316 stainless steel

Abstract Samples with two different surface topographies were diffusion bonded to chemomechanically-polished surfaces showing significantly greater departure from conventional pore elimination models than for samples bonded with two roughened surfaces. These findings suggest differences in the way faying surfaces interact during early plastic deformation. Ground and cold-rolled samples were characterized and bonded to polished samples, simplifying faying surface interactions for finite element analysis. Conventional diffusion bonding models were found to significantly overestimate the percent bonded area for both ground and cold-rolled samples, with the overestimation more severe for the ground samples. Finite element analyses of the initial plastic deformation reveal 50 % more contact area for the cold-rolled surface with one-quarter the amount of strain compared with ground samples with nearly equivalent root mean square surface roughness. This was attributed to the cold-rolled surface being dominated by a few deep pits with smoother regions in between. Comparison of the ground sample results with the technical literature suggests that the surface asperities of ground surfaces may interleave during diffusion bonding.
First principles inelastic mean free paths coupled with Monte Carlo simulation of secondary electron yield of Cu-Ni, Cu-Zn, and Mo-Li

Secondary electron yield (SEY) is relevant for widely used characterization methods (e.g., secondary electron spectroscopy and electron microscopy) and materials applications (e.g., multipactor effect). Key quantities necessary for understanding the physics of electron transport in materials and simulation of SEY are electron mean free paths (MFPs). This paper explores the impact of alloying on MFPs and SEY for Cu-Ni, Cu-Zn, and Mo-Li alloys relative to their component metals Cu, Ni, Zn, Mo, and Li. Density functional theory calculations yield density of states, Fermi energy, work function, and frequency- and momentum-dependent energy loss function. These material properties were used to calculate MFPs and Monte Carlo simulations were performed to obtain energy dependent SEY for the alloys as well for the component metals. The results show that MFPs and SEYs of the studied alloys lie between those of component pure elements but are not a simple composition weighted average. Detailed analysis of the secondary electron generation and emission process shows that the changes in the SEY of alloys relative to the SEY of their component metals depend on the changes in both electronic structure and dielectric properties of the material.
Can You Teach a Teen New Tricks? Problem Solving Skills Training Improves Oral Medication Adherence in Pediatric Patients with Inflammatory Bowel Disease Participating in a Randomized Trial

Background Medication nonadherence is associated with higher disease activity, greater health care utilization, and lower health-related quality of life in pediatric inflammatory bowel diseases (IBD). Problem solving skills training (PSST) is a useful tool to improve adherence in patients with chronic diseases but has not been fully investigated in IBD. This study assessed feasibility, acceptability, and preliminary efficacy of PSST in pediatric IBD. Methods Recruitment occurred during outpatient clinic appointments. After completion of baseline questionnaires, families were randomized to a treatment group or wait-list comparison group. The treatment group received either 2 or 4 PSST sessions. Youth health-related quality of life was assessed at 3 time points, and electronic monitoring of oral medication adherence occurred for the study duration. Results Seventy-six youth (ages 11-18 years) on an oral IBD maintenance medication participated. High retention (86%) and treatment fidelity rates (95%) supported feasibility. High satisfaction ratings (mean values ≥4.2 on 1-5 scale) supported intervention acceptability. Modest increases in adherence occurred after 2 PSST sessions among those with imperfect baseline adherence (d = 0.41, P 0.05). Conclusions Phone-delivered PSST was feasible and acceptable. Efficacy estimates were similar to those of lengthier interventions conducted in other chronic illness populations. Older adolescents benefited more from the intervention than their younger counterparts.
Enhanced Production of Wild-Type P53 Inhibits Growth and Differentiation of Normal Foreskin Epithelial Cells but not Cell Lines Containing Human Papillomavirus DNA

Normal human epithelial cells cultured from foreskin or cervical epithelia can be immortalized by a subset of HPV DNAs associated with a high risk of cervical cancer (Pirisi et al., 1987; Woodworth et al., 1989). The HPV-immortalized cell lines exhibit aberrant growth and differentiation when maintained as organotypic cultures (McCance et al., 1988) or in vivo (Woodworth et al., 1990). It is hypothesized that HPV oncoproteins E6 and E7 contribute to immortalization through their ability to bind the products of the tumor suppressor genes p53 and Rb, respectively (Munger et al., 1992).
Emergence of Linguistic Communication: Studies on Grey Parrots

Most studies on the evolution of communication systems concentrate on the primate lineage, ignoring the concept of parallel lines of evolution. Although phylogenetically remote from humans, some birds—particularly Grey parrots—share many cognitive and communicative abilities with humans. On certain tasks, they demonstrate processing abilities comparable to 5-6 year-old humans; they learn very simple vocal syntactic patterns and referential elements of human communication, but only through social interaction and in a manner that proceeds in ways similar to those of humans. Given this knowledge of vocal learning in birds, of the effects of social interaction on such learning, and of birds’ complex cognitive abilities, we should not ignore the avian line if we wish to determine the evolutionary pressures that purportedly affected the evolution of complex communication systems—particularly vocal systems—and develop theories and models that can be tested.
Two Hadron Interaction

In the past year nucleon-nucleon physics has been moving ahead rapidly especially on the experimental side. Data reported last year at the Vancouver and Tokyo conferences cleared up some old ambiguities below 50 MeV in the P states and the 3S1−3D1 mixing parameter. Evidence from TRIUMF and ANL was beginning to give us an inkling of the impact that the new data from intermediate energies would have. Since then the analysis of the nucleon-nucleon data from the BASQUE group at TRIUMF has shown that there are important revisions from the Livermore phase shifts. Indeed their new phases allow the possibility of some structure even in their energy range(1). The polarized beam, polarized target results from ANL now indicate with some assurance that there is a 3F3 resonance near 2.26 GeV barycentric energy and probably the expected singlet 1D2 resonance near 2.10 GeV(2). Also new experimental results this past year from Kamae et al have confirmed and extended their 1977 results, which show a large peak in the proton polarization in deuteron photodisintegration at an energy corresponding to a possible dibaryon resonance at 2.35 GeV(3). Some of the theoretical contributions to this conference which I will present later bear on this new experimental information.
Elasticity Solutions for the Buckling of Thick Composite and Sandwich Cylindrical Shells Under External Pressure

Thick composite and sandwich shells are used in many naval submersible structures and in other applications such as space vehicles. Stability under the prevailing high external pressure in deep ocean environments is of primary concern. In many other applications the loading involves a combination of external pressure and axial compression. It is well known that for these structures the simple classical formulas are in much error, due to both the large thickness and the large extensional over shear modulus ratios of modern composite and sandwich materials. Although there exist several advanced theories, such as first order shear and higher order shear theories, each based on a specific set of assumptions, it is not easy to determine the accuracy and range of validity of these advanced models unless an elasticity solution exists. This paper presents the research performed over the last 15 years on benchmark elasticity solutions to the problem of buckling of (i) orthotropic homogeneous cylindrical shells and (ii) sandwich shells with all constituent phases i.e., facings and core assumed to be orthotropic. The paper focuses on uniform external pressure loading. In this context, the structure is considered a three-dimensional body. The results show that the shell theory predictions can produce in many cases highly non-conservative results on the critical loads. A comparison with the corresponding formulas from shell theory with shear included, is also performed. The present solutions provide a means of accurately assessing the limitations of the various shell theories in predicting stability loss.
The utilization of N-acetylcysteine and 2-oxothiazolidine-4-carboxylate by rat hepatocytes is limited by their rate of uptake and conversion to cysteine

N-Acetyl-L-cysteine (NAC) and L-2-oxothiazolidine-4-carboxylate (OTC) are converted enzymatically to cysteine and have been used to stimulate hepatic glutathione synthesis. Using hepatocytes isolated from male Sprague-Dawley rats and 35S-labeled substrates, the uptake and metabolism of these cysteine precursors was measured and compared with those for cells provided with an equimolar amount of cysteine. Cysteine was utilized more rapidly than NAC or OTC for sulfate and taurine production and more rapidly than OTC for glutathione production. N-Acetyl-L-cysteine itself was taken up slowly by hepatocytes, but deacetylation of NAC to cysteine seemed to occur extracellularly. Utilization of OTC seemed to be limited by a low rate of uptake and slow intracellular conversion to cysteine. The rate of accumulation of [35S]glutathione from OTC was low compared to that from other substrates, but glutathione production accounted for 78% of the measured OTC metabolism. Although the rate of accumulation of [35S]glutathione was similar for hepatocytes incubated with [35S]cysteine or [35S]NAC, glutathione synthesis accounted for a higher percentage of NAC metabolism than of cysteine metabolism (62-81% vs. 46%). The apparent preferential distribution of OTC and NAC to glutathione vs. taurine and sulfate can be partly explained by a lower rate of substrate availability, but another unknown mechanism also appears to favor the conversion of NAC to glutathione.
A new autoregressive estimator for the estimation of the frequencies of a sinusoidal process corrupted with noise

The authors propose an autocorrelation-based method for determining the autoregressive parameters of a signal containing sinusoids. This method does not use the zero-lag autocorrelation value of the signal and is thus immune to the error caused by an additive white noise present in the signal. The autoregressive parameters are then used to determine the frequencies of the sinusoids. The method requires only 2p autocorrelation values, where p is the number of sinusoids. Thus, this method finds applications where the number of autocorrelations to be calculated is to be a minimum. A comparison of the method with other methods shows that over some frequency range the method has the lowest error. A disadvantage of the method is that the signal should be sampled at a rate at least four times the highest frequency in the signal if sampled data are used to estimate the autocorrelation values. >
The effects of three levels of lick-contingent footshock on schedule-induced polydipsia

Nine food deprived female albino rats were divided into three shock groups with three subjects in each group. The subjects were subjected to five successive experimental phases utilizing baseline, intermittent schedule, and intermittent schedule plus contingent shock condition, with individual subject water intakes recorded for each 60-min daily session across all phases. During the experimental shock phase, Groups 1, 2, and 3 received 2.0, 1.0, and 0.1 mA postpellet lick-contingent shock, respectively. 2.0-mA shocks disrupted emotionally induced drinking, whereas 1.0-mA shocks had no effect on emotionally induced drinking and 0.1-mA shock facilitated drinking. These results have important implications for the consideration of using punishment techniques as treatments in the eradication of undesirable behaviors.
Late Cretaceous paleogeography of Wrangellia: Paleomagnetism of the MacColl Ridge Formation, southern Alaska, revisited

Volcanic and sedimentary strata of the Late Cretaceous MacColl Ridge Formation were sampled and demagnetized to reevaluate the paleomagnetically derived paleolatitude of the allochthonous Wrangellia terrane. Characteristic directions from 15 sites representing ∼750 m of the MacColl Ridge Formation (80 Ma) reveal a reversed-polarity primary magnetization yielding a paleomagnetic pole at 126°E, 68°N, A 95 = 9°. Comparison of this pole with the Late Cretaceous reference pole for North America indicates 15° ± 8° of latitudinal displacement (northward) and 33° ± 25° of counterclockwise rotation. In contrast to previously reported low paleolatitudes (32° ± 9°N) for the MacColl Ridge Formation, these new results place the Wrangellia terrane at a moderate paleolatitude (53° ± 8°N) in the Late Cretaceous.
Multiple Contexts of School Engagement: Moving Toward a Unifying Framework for Educational Research and Practice

This article discusses the school engagement literature and offers a conceptual framework with the intention of developing a common terminology to more efficiently organize research and practice. Three distinct perspectives are outlined in relation to school engagement: psychological, educational, and developmental. Four main contexts of school-based engagement are identified, including the student, peers, classroom, and the school environment. Although some researchers have focused on students at risk for negative developmental outcomes, the proposed model postulates that all youth benefit from school engagement. Overall, the intent of this new framework is to support efforts to promote positive student outcomes, increase psychosocial competence and efficacy, and promote life-long learning.
SELECTIVITY OF EXECUTIVE FUNCTION DEFICITS IN MILD COGNITIVE IMPAIRMENT

Impairment in executive cognition (EC) is now recognized as relatively common among older persons with mild cognitive impairment (MCI), and may be predictive of the development of dementia. However, both MCI and executive functioning are broad and heterogeneous constructs. The present study sought to determine whether impairments in specific domains of EC are associated with specific subtypes of MCI. 124 MCI patients were divided into four subgroups (amnestic versus nonamnestic, and single- versus multiple-domain) based on their performance of widely-used neuropsychological screening tests. These patients and 68 normal elderly were administered 18 clinical and experimental tests of executive function. Principal components analysis suggested two highly reliable EC components, planning/problem-solving and working memory, and a less reliable third component, judgment. Planning/problem-solving and working memory, but not judgment, were impaired among the MCI patients. This was true even among those with Apure amnestic@ MCI, the least impaired group overall. Multiple-domain MCI patients had more severe impairments in planning/problem-solving and working memory than single-domain patients, leading to the supposition that they, not pure amnestic MCIs, are at highest risk of imminent dementia.
Spark-induced agglomeration of aqueous polymeric suspensions

Discharging a high-energy spark underwater creates a shock wave that dissipates through an acoustic field. Colloidal acrylate polymers suspended in water containing dissolved calcium are agglomerated as a result. The degree of agglomeration increases with the number of sparks applied and with increasing calcium content. The calcium decreases the charge on the colloidal particles and thereby increases their propensity to be agglomerated by the acoustic wave. These observations are confirmed in full-scale trials in paper recycling mills where sparking improves the efficiency of centrifugal cleaners by increasing the particle size of the contaminants.
The hydrogen-fueled internal combustion engine : a technical review.

A review is given of contemporary research on the hydrogen-fueled internal combustion engine. The emphasis is on light- to medium-duty engine research. We first describe hydrogen-engine fundamentals by examining the engine-specific properties of hydrogen and surveying the existing literature. Here it will be shown that, due to low volumetric efficiencies and frequent preignition combustion events, the power densities of premixed or port-fuel-injected hydrogen engines are diminished relative to gasoline-fueled engines. Significant progress has been made in the development of advanced hydrogen engines with improved power densities. We discuss several examples and their salient features. Finally, we consider the overall progress made and provide suggestions for future work.
Cortical representations of olfactory input by trans-synaptic tracing

In the mouse, each class of olfactory receptor neurons expressing a given odorant receptor has convergent axonal projections to two specific glomeruli in the olfactory bulb, thereby creating an odour map. However, it is unclear how this map is represented in the olfactory cortex. Here we combine rabies-virus-dependent retrograde mono-trans-synaptic labelling with genetics to control the location, number and type of 'starter' cortical neurons, from which we trace their presynaptic neurons. We find that individual cortical neurons receive input from multiple mitral cells representing broadly distributed glomeruli. Different cortical areas represent the olfactory bulb input differently. For example, the cortical amygdala preferentially receives dorsal olfactory bulb input, whereas the piriform cortex samples the whole olfactory bulb without obvious bias. These differences probably reflect different functions of these cortical areas in mediating innate odour preference or associative memory. The trans-synaptic labelling method described here should be widely applicable to mapping connections throughout the mouse nervous system.
Fluorescent Indicators of Peptide Cleavage in the Trafficking Compartments of Living Cells: Peptides Site-Specifically Labeled with Two Dyes

When cells are infected with viruses, they notify the immune system by presenting fragments of the virus proteins at the cell surface for detection by T cells. These proteins are digested in the cytoplasm, bound to the major histocompatibility complex I glycoprotein (MHC-I) in the endoplasmic reticulum, and transported to the cell surface. The peptides are cleaved to the precise lengths required for MHC-I binding and detection by T cells. We have developed fluorescent indicators to study the cleavage of peptides in living cells as they are transported from the endoplasmic reticulum to the Golgi apparatus. Specific viral peptides known to be "trimmed" prior to cell surface presentation were labeled with two dyes undergoing fluorescence resonance energy transfer (FRET). When these fluorescent peptides were proteolytically processed in living cells, FRET was halted, so that each labeled fragment and the intact peptide exhibited different fluorescence spectra. Such fluorescent cleavage indicators can be used to study a wide range of biological behaviors dependent on peptide or protein cleavage. However, labeling a peptide with two dyes at precise positions can present a major obstacle to using this technique. Here, we describe two approaches for preparing doubly labeled cleavage indicator peptides. These methods are accessible to researchers using standard laboratory techniques or, for more demanding applications, through cooperation with commercial or core peptide synthesis services using minor modifications of standard synthetic procedures.
Asynchronous Multi-Centralized Cooperative Localization

This paper presents a generalized framework for inter-robot information-transfer schemes in Multi-Centralized Cooperative Localization (MC-CL) under asynchronous communication, i.e., when the communication graph associated with the mobile robot network is time-varying and intermittently disconnected. Specifically, two information-transfer schemes, which differ based on their communication bandwidth requirements per link, are discussed. Even under asynchronous communication constraints, these schemes enable robots to compute pose estimates identical to those generated using the centralized CL framework, albeit delayed. For each of these schemes, necessary and sufficient conditions for the communication-graph connectivity, that enable each robot to generate the centralized estimates, are developed. Moreover, detailed description of these schemes, along with their communication-complexity analysis and analytical results for the expected time delay in obtaining these estimates, are presented. Lastly, simulation results are used to validate the performance (the trade-off between communication link bandwidth and accuracy/delay) of these information-transfer schemes.
Predicting responses of photosynthesis and root fraction to elevated [CO2]a: interactions among carbon, nitrogen, and growth*

At elevated atmospheric CO2 concentrations ([CO2]a), photosynthetic capacity (Amax) and root fraction (ηR, the ratio of root to plant dry mass) increased in some studies and decreased in others. Here, we have explored possible causes of this, focusing on the relative magnitudes of the effects of elevated [CO2]a on specific leaf (nm) and plant (np) nitrogen concentrations, leaf mass per unit area (h), and plant nitrogen productivity (α). In our survey of 39 studies with 35 species, we found that elevated [CO2]a led to decreased nm and np in all the studies and to increased h and α in most of the studies. The magnitudes of these changes varied with species and with experimental conditions. Based on a model that integrated [CO2]a-induced changes in leaf nitrogen into a biochemically based model of leaf photosynthesis, we predicted that, to a first approximation, photosynthesis will be upregulated (Amax will increase) when growth at increased [CO2]a leads to increases in h that are larger than decreases in nm. Photosynthesis will be downregulated (Amax will decrease) when increases in h are smaller than decreases in nm. The model suggests that photosynthetic capacity increases at elevated [CO2]a only when additional leaf mesophyll more than compensates the effects of nitrogen dilution. We considered two kinds of regulatory paradigms that could lead to varying responses of ηR to elevated [CO2]a, and compared the predictions of each with the data. A simple static model based on the functional balance concept predicts that ηR should increase when neither np nor h is very responsive to elevated [CO2]a. The quantitative and qualitative agreement of the predictions with data from the literature, however, is poor. A model that predicts ηR from the relative sensitivities of photosynthesis and relative growth rate to elevated [CO2]a corresponds much more closely to the observations. In general, root fraction increases if the response of photosynthesis to [CO2]a is greater than that of relative growth rate.
Tetraoxaspiroalkanes for polymerization stress reduction of Silorane resins

This study involved the synthesis and characterization of tetraoxaspiroalkane monomers and evaluated their potential to reduce polymerization stress when formulated in a Silorane resin system. The tetraoxaspiroalkane monomers had two main structural features (a) two different types of core ring structures (a 1,5,7,11-tetraoxaspirocyclic ring or a 2,4,8,10-tetraoxaspirocyclic ring) and (b) four different types of ring substituents (normal alkyl, allyloxyalkyl, trimethylsilylalkyl, or oxabicycloalkyl). The resin formulations contained (a) 20 mol % of a 1,5,7,11- or 2,4,8,10-tetraoxaspiroalkyl monomer; (b) a phenylmethylsilane containing two oxabicycloheptyl groups; (c) a cyclotetrasiloxane containing four oxabicycloheptyl groups; and (d) a photocationic initiator system. Three main aspects were studied (a) the photoreactivity of the formulations using PDSC, (b) photopolymerization stress, and (c) mechanical properties (flexural elastic modulus, ultimate strength, and work of fracture) which were measured using an electromagnetic mechanical testing machine. The main findings were (a) formulations containing 2,4,8,10-tetraoxaspiroalkane monomers had measured net enthalpies greater than those containing 1,5,7,11-tetraoxaspiroalkane monomers, and above those calculated for addition of an inert diluent; (b) all formulations containing tetraoxaspiroalkane monomers exhibited photopolymerization stress values that were 40–99% less than the nonaddition control; (c) the formulation containing a 1,5,7,11-tetraoxaspiroalkane monomer with an oxirane functionality had mechanical properties that were not significantly different from the nonaddition control. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Conference on Computers, Freedom and Privacy: Going Strong in its 14th Year

Reports on the 14th Annual Conference on Computers, Freedom and Privacy, held in Berkeley, California in April 2004. Outlines the themes of the papers presented in the 12 plenary sessions.
An Inhibitor of Oxalic Acid Oxidase in Beet Extracts

Oxalic acid oxidase, studied in spinach leaves by Laties (7) and in sugar beet leaves by both Arnon and Whatley (1) and Finkle and Arnon (5), has been demonstrated by the present authors in a thin peripheral layer of beet roots. The enzyme is here associated with a particulate constituent of the cells, probably mitochondrial in nature. Extreme fluctuations in activity were encountered, so that active preparations usually could be obtained with ease from the small (red) roots of commercial "beet greens" and also from young sugar beet roots grown in the greenhouse, but not from more mature sugar beet roots harvested in the greenhouse in July and August. Laties (7) has reported a phenomenon for spinach which is at least remotely similar: Leaves of plants grown at 260 C yielded active preparations, but those of specimens raised at 180 C did not. He did not analyze this situation. In Beta, the present authors found that homogenates of older sugar beet roots strongly inhibited the oxalic oxidase activity of red beet particles. This fact argues in favor of the possibility that, in the older beet roots themselves, the oxalic acid oxidase is not lacking but is merely suppressed in its activity by some inhibitor. The present article demonstrates that this is inleed the situation. Identification of the inhibitor was made possible by substituting a solution of moss oxalic acid oxidase for the particulate enzyme from red beet. In addition to being a more convenient method, this allowed a more quantitative approach.
Attack graph generation and analysis

Attack graphs represent the ways in which an adversary can exploit vulnerabilities to break into a system. System administrators analyze these attack graphs to understand where their system's weaknesses lie and to help decide which security measures will be effective to deploy. In practice, attack graphs are produced manually by Red Teams. Construction by hand, however, is tedious, error-prone, and impractical for attack graphs larger than a hundred nodes. In this talk I present a technique, based on model checking, for generating attack graphs automatically. I also describe different analyses that system administrators can perform in trading off one security measure for another or in using attack graphs in intrusion detection. Work on generating attack graphs is joint with Somesh Jha and Oleg Sheyner; on analyzing them, joint with Oleg Sheyner and Oren Dobzinski.
To rule Jerusalem

Twentieth-century Jerusalem is doubly divided. As well as being a holy site for both Judaism and Islam, the city contains secular Israelis and Palestinians who ground their respective national identities within its borders. "To Rule Jerusalem" provides a historical and ethnographic account of how Jerusalem has become the battleground for conflicts both within and between the Israeli and Palestinian communities. Roger Friedland and Richard Hecht examine the relation between Zionism and Judaism and between Palestinian nationalism and Islam. Based on hundreds of interviews with powerful players and ordinary citizens over the course of a decade, this book evokes the ways in which these conflicts are experienced and managed in the life of the city. "To Rule Jerusalem" is a compelling study of the intertwining of religion and politics, exploring the city simultaneously as an ordinary place and an extraordinary symbol.
All Cues Are Not Created Equal: The Case for Facilitating the Acquisition of Typical Weighting Strategies in Children With Hearing Loss

Purpose One task of childhood involves learning to optimally weight acoustic cues in the speech signal in order to recover phonemic categories. This study examined the extent to which spectral degradation, as associated with cochlear implants, might interfere. The 3 goals were to measure, for adults and children, (a) cue weighting with spectrally degraded signals, (b) sensitivity to degraded cues, and (c) word recognition for degraded signals. Method Twenty-three adults and 36 children (10 and 8 years old) labeled spectrally degraded stimuli from /bɑ/-to-/wɑ/ continua varying in formant and amplitude rise time (FRT and ART). They also discriminated degraded stimuli from FRT and ART continua, and recognized words. Results A developmental increase in the weight assigned to FRT in labeling was clearly observed, with a slight decrease in weight assigned to ART. Sensitivity to these degraded cues measured by the discrimination task could not explain variability in cue weighting. FRT cue weighting explained sig...