cssi/SciSciGPT-SciSciNet huggingface dataset:
Ab initio molecular dynamics simulations of the oxygen reduction reaction on a Pt(111) surface in the presence of hydrated hydronium (H3O)(+)(H2O)2: direct or series pathway?

Car−Parrinello molecular dynamics simulations have been performed to investigate the oxygen reduction reaction (ORR) on a Pt(111) surface at 350 K. By progressive loading of (H3O)+(H2O)2,3 + e- into a simulation cell containing a Pt slab and O2 for the first reduction step, and either products or intermediate species for the subsequent reduction steps, the detailed mechanisms of the ORR are well illustrated via monitoring MD trajectories and analyzing Kohn−Sham electronic energies. A proton transfer is found to be involved in the first reduction step; depending on the initial proton−oxygen distance, on the degree of proton hydration, and on the surface charge, such transfer may take place either earlier or later than the O2 chemisorption, in all cases forming an adsorbed end-on complex H−O−O*. Decomposition of H−O−O* takes place with a rather small barrier, after a short lifetime of approximately 0.15 ps, yielding coadsorbed oxygen and hydroxyl (O* + HO*). Formation of the one-end adsorbed hydrogen peroxi...
Surface material dependence of beam-tilted-foil orientation and alignment

Abstract When compared with carbon foil data, reduced beam-tilted-foil orientation and alignment magnitudes are observed as a function of foil tilt angle and amount of evaporated surface gold.
Did Asperger's Cases Have Asperger Disorder? A Research Note

With publication of the fourth edition of the Diagnostic and statistical manual of mental disorders (DSM-IV), standardized criteria for Asperger Disorder, a putative subtype of Pervasive Developmental Disorder, are now available. This paper examines the four cases Asperger originally presented in his seminal paper (1991/1994), using DSM-IV criteria to determine whether a diagnosis of Autistic or Asperger Disorder is most appropriate. We found that all four cases met DSM-IV criteria for Autistic Disorder, rather than Asperger Disorder. This suggests that the syndrome Asperger originally described may not be captured by present diagnostic criteria. Implications for future research are discussed.
Estimating the Probability Distribution of Annual Maximum Levels on the Great Lakes

Abstract The traditional approach to estimating the probability distribution of annual maximum water levels on the Great Lakes has been to treat the observed water level series as random samples, ignoring the fact that annual maximum lake levels are correlated in time. This paper provides an approach for estimating lake level probabilities which explicitly accounts for this correlation. The approach is based on decomposing annual maximum water levels into two components, which separately account for hydrologic variations and storm effects. By conditioning the distribution of the hydrologic component on an initial level and by convoluting the resulting distribution with the distribution of storm effects, the conditional probability distribution of annual maximum water levels is obtained for any number of years in the future. The approach is illustrated using data from Lake Erie.
Candidate gene studies of antipsychotic drug efficacy and drug-induced weight gain.

Converging data suggest that the identification of the molecular variants that influence antipsychotic drug response may soon be feasible. For the most part, these studies have focused on the new atypical antipsychotic agents, particularly clozapine. Although initial data in this regard has been inconclusive, recent studies have suggested that variation in the gene that codes for the dopamine D2 receptor (DRD2) may significantly influence the clinical efficacy of a number of typical and atypical antipsychotic drugs, perhaps via a variant that influences messenger RNA (mRNA) stability and translation. Studies of antipsychotic-induced weight gain have been more consistent than studies of antipsychotic drug efficacy, perhaps because weight dysregulation represents a more powerful phenotype for genetic studies, with a specific single nucleotide polymorphism (SNP) in the 5-hydroxytryptamine 2C (5-HT2C)receptor being associated with weight gain across diverse samples. Larger, more comprehensive studies are needed to confirm these results, but taken together, they suggest that pharmacogenetic strategies may be critical towards gaining a more precise understanding of the mechanism of action of antipsychotic drugs in the treatment of schizophrenia.
EVIDENCE FOR THE CLOSE CLIMATIC CONTROL OF NEW ENGLAND VEGETATION HISTORY

Sediments from lakes in the northeastern United States (“New England”) document climatic changes over the past 15 000 years that may, in turn, explain the long- term history of regional forest development. A rise in New England temperatures ∼14 600 yr BP (calendar years before present) coincided with the initial increase in spruce (Picea spp.) populations after deglaciation. Later temperature fluctuations correlated with changes in spruce forest composition until 11 600 yr BP, when evidence for a shift to warm, dry conditions agrees with the replacement of spruce by pine (Pinus spp.) populations. Raised lake levels indicate increased moisture availability by 8200 yr BP when mesic hemlock (Tsuga canadensis) and beech (Fagus grandifolia) populations replaced the dry-tolerant pines. Cooler-than-modern temperatures, however, persisted until 6000 yr BP and appear to have limited the expansion of hickory (Carya spp.) populations. Similarly, moisture- dependent chestnut (Castanea dentata) populations did not inc...
Further comments on conformal symmetry in the Weyl theory

(x) S. D+ BERGER: Lef t . Nuovo Cimento, 11, 89 (1974). I n tlle p resen t l e t t e r we use t h e no ta t ion for t he Dirae m a t r i c e s a nd spiaors givcr~ in th i s p rev ious communica t ion . This p a p e r will hencefor th bc re fe r red to as I . (:) A. O. BARUT: Spr inger Tracts in Modern Phys ics , Vol. 50 (Berlin, 1969), p. 5. (a) G. MACK and A. SALA.~t: A n n . O] P h y s . , 53, 178 (1969).
Sodium bicarbonate and alfalfa hay additions to wheat silage diets fed to lactating dairy cows.

Two experiments were conducted to examine dietary effects of .8% sodium bicarbonate and 1.4 kg/d of alfalfa hay on performance and rumen metabolism of lactating dairy cows fed 50% wheat silage and 50% concentrate (dry basis). In Experiment 1 with 12 midlactation Holsteins in a 4 × 4 Latin square design, intake, milk production, and milk composition were not affected by treatment. Dietary sodium bicarbonate and alfalfa hay did not alter blood, rumen, or fecal pH. Rumen volatile fatty acid pattern was not affected by sodium bicarbonate, but addition of hay resulted in higher molar percentage propionate and lower acetate: propionate ratios. In Experiment 2 with 32 early lactation cows (20 Holsteins and 12 Jerseys) in a complete randomized block design, supplementation of sodium bicarbonate, alfalfa hay, or both did not affect intake, milk production, or milk composition in the first 8 wk of lactation. Blood, rumen, and fecal pH were not affected by treatment. Dietary sodium bicarbonate did not alter ruminal volatile fatty acid profile, whereas addition of hay increased molar proportion acetate and decreased molar proportion butyrate. A shift in rumen fermentation was observed across treatments from wk 1 through 8 postpartum with molar proportions of acetate and butyrate increasing and molar proportion of propionate decreasing.
Atom cooling: Ultracold Fermi gas on a chip

Trapped atomic Fermi gases currently provide models of neutron stars, high-temperature superconductors, and even the quark–gluon plasma that comprised the early universe. The ability to produce these important systems on a chip could also open the way to their practical use.
Increased Hippocampal 5‐Lipoxygenase mRNA Content in Melatonin‐Deficient, Pinealectomized Rats

Melatonin is neuroprotective because of its antioxidative action, but it also can modify neuronal vulnerability by altering gene expression. 5-Lipoxygenase (5-LO) gene expression is suppressed by the binding of melatonin to its high-affinity nuclear receptors. Recently, we reported that in rats the melatonin deficiency elicited by pinealectomy increases hippocampal susceptibility to excitotoxic injury. Here we have hypothesized that pinealectomy may increase hippocampal vulnerability by eliminating the tonic inhibitory action of melatonin on 5-LO gene expression. Sham-pinealectomized controls and pinealectomized rats were killed 15 days after surgery. Their hippocampi were dissected, and total RNA was extracted and processed for quantitative reverse transcription-polymerase chain reaction assay of 5-LO and cyclophilin mRNAs. Mutated primers were used as internal standards to assay attomole quantities of these two specific mRNAs per microgram of total RNA; the ratio 5-LO/cycophilin was used to compare samples from control and pinealectomized rats. Pinealectomy increased hippocampal 5-LO mRNA content by about threefold. These results support our hypothesis that melatonin deficiency may abate the tonic inhibition of 5-LO mRNA expression and thereby up-regulate 5-LO gene expression, which in turn would increase the brain's synthesis rate of potentially harmful eicosanoids, leukotrienes.
Transient Amnesia After Coiling of a Posterior Circulation Aneurysm

Background Acute amnesia can be caused by medication effect, transient global amnesia, ischemia, metabolic abnormalities, and seizures.
High resolution models of transcription factor-DNA affinities improve in vitro and in vivo binding predictions

Accurately modeling the DNA sequence preferences of transcription factors (TFs), and using these models to predict in vivo genomic binding sites for TFs, are key pieces in deciphering the regulatory code. These efforts have been frustrated by the limited availability and accuracy of TF binding site motifs, usually represented as position-specific scoring matrices (PSSMs), which may match large numbers of sites and produce an unreliable list of target genes. Recently, protein binding microarray (PBM) experiments have emerged as a new source of high resolution data on in vitro TF binding specificities. PBM data has been analyzed either by estimating PSSMs or via rank statistics on probe intensities, so that individual sequence patterns are assigned enrichment scores (E-scores). This representation is informative but unwieldy because every TF is assigned a list of thousands of scored sequence patterns. Meanwhile, high-resolution in vivo TF occupancy data from ChIP-seq experiments is also increasingly available. We have developed a flexible discriminative framework for learning TF binding preferences from high resolution in vitro and in vivo data. We first trained support vector regression (SVR) models on PBM data to learn the mapping from probe sequences to binding intensities. We used a novel -mer based string kernel called the di-mismatch kernel to represent probe sequence similarities. The SVR models are more compact than E-scores, more expressive than PSSMs, and can be readily used to scan genomics regions to predict in vivo occupancy. Using a large data set of yeast and mouse TFs, we found that our SVR models can better predict probe intensity than the E-score method or PBM-derived PSSMs. Moreover, by using SVRs to score yeast, mouse, and human genomic regions, we were better able to predict genomic occupancy as measured by ChIP-chip and ChIP-seq experiments. Finally, we found that by training kernel-based models directly on ChIP-seq data, we greatly improved in vivo occupancy prediction, and by comparing a TF's in vitro and in vivo models, we could identify cofactors and disambiguate direct and indirect binding.
Teaching Students Who Struggle With Learning to Think Before, While, and After Reading: Effects of Self-Regulated Strategy Development Instruction

Explicit strategy instruction combined with student-directed self-regulation in conjunction with cognitive strategies has proven effective in supporting low-achieving students' reading comprehension. Experts have extended 1 such approach, self-regulated strategy development (SRSD) for the expository reading comprehension Think before reading, think While reading, think After reading (TWA) strategy, by integrating instruction for writing, language development, and prompted discourse into the instructional framework. Researchers have found positive performance effects following SRSD for TWA instruction across reading comprehension and language measures, oral and written summarization, oral and written retelling, and informative essay writing. Findings from 8 empirical studies have provided insights for research and practice.
Docosahexaenoic acid block of neuronal voltage-gated K+ channels: subunit selective antagonism by zinc.

Abstract The ω-3 polyunsaturated fatty acid docosahexaenoic acid is highly enriched in neuronal membranes, and several studies suggest that DHA is critical for neuronal development. We have investigated the effects of exogenously applied DHA on voltage-gated K + channels using patch-clamp techniques. DHA produced a concentration-dependent inhibition of the sustained outward current in isolated neocortical neurons. This blocking action was examined in more detail with two cloned neuronal K + channels (Kv1.2 and Kv3.1a) expressed in mammalian fibroblasts. DHA produced a potent inhibition of depolarization-activated K + currents from cells expressing these channels ( K d values, 1.8 ± 0.1 μM and 690 ± 60 nM, for Kv1.2 and Kv3.1a, respectively, at +40 mV). The DHA block of both channel types was rapidly reversed (∼ 2 sec) by bovine serum albumin, which binds the fatty acid. Micromolar concentrations of extracellular Zn 2+ non-competitively antagonized DHA inhibition of Kv1.2 channels, whereas there was little effect on DHA block of Kv3.1a channels. Experiments with membrane patches from Kv1.2 transfected cells demonstrated that the DHA block occurred from the outside, suggesting that the fatty acid interacts directly with an external domain of the ion channel. DHA may serve as a local messenger molecule that selectively modulates the activity of certain voltage-gated K + channels in a Zn 2+ -dependent fashion. Copyright © 1996 Elsevier Science Ltd
Annexin V-mediated calcium flux across membranes is dependent on the lipid composition: Implications for cartilage mineralization

Annexin V is a major component of matrix vesicles and has a role in mediating the influx of Ca2+ into these vesicles, thus promoting the initiation of hypertrophic cartilage matrix mineralization. However, the mechanisms and factors regulating annexin V-mediated Ca2+ influx into these vesicles are not well understood. Since the lipid composition of matrix vesicles differs from that of the plasma membrane of chondrocytes and is rich in phosphatidylserine, we asked whether the lipid composition may regulate annexin V function. We prepared liposomes containing different concentrations of phosphatidylserine and determined how the lipid composition affected (a) the interactions between annexin V and liposomes and (b) annexin V-mediated Ca2+ influx into the liposomes. We found that annexin V was able to bind to every liposome tested. However, we observed the most prominent increases in tryptophan 187 emission intensity, a measure of the degree of interactions between annexin V and lipid bilayers, only with lipo...
Determinants of insulin response to glucose absorption from human small bowel

Abstract In normal human volunteers, segments of small bowel were isolated with a fourlumen tube and perfused with solutions containing 154 or 771 m M glucose or with control solution not containing glucose. As shown by path analysis, insulin response was determined both by rate of glucose absorption and rise of serum glucose, and it persisted for at least 1 hr after termination of glucose absorption. It was independent of the site of perfusion in the upper small bowel and of the tonicity of intestinal contents. Exocrine pancreatic secretion was not stimulated during absorption of glucose. These results are compatible with the possibility that secretin is the hormone which augments the insulin response to glucose absorbed from the small bowel.
Reirradiation of recurrent head and neck cancers with curative intent

In patients with recurrent, previously irradiated head and neck cancer, the traditional therapy of palliative single- or multi-agent chemotherapy yields a 30% to 40% response rate with median survival durations of 8 to 10 months. However, long-term survival is rarely observed. Reirradiation with or without concurrent chemotherapy is currently under investigation as a treatment option in these patients. While reirradiation without chemotherapy appears to be effective in recurrent nasopharynx cancer cases, the use of concomitant chemotherapy with reirradiation appears to offer improved outcomes based on phase I/II data in other head and neck sites. Recent studies indicate that long-term survival of patients is possible following reirradiation in a minority of cases despite severe acute and chronic toxicities. Reirradiation with chemotherapy is appropriate for patients with a goal of long-term local control of disease and curative intent, despite the risk of significant acute and late toxicities.
Endotracheal tube biofilm inoculation of oral flora and subsequent colonization of opportunistic pathogens

Endotracheal (ET) tubes accumulate a biofilm during use, which can harbor potentially pathogenic microorganisms. The enrichment of pathogenic strains in the biofilm may lead to ventilator-associated pneumonia (VAP) with an increased morbidity rate in intensive care units. We used quantitative PCR (qPCR) and gene surveys targeting 16S rRNA genes to quantify and identify the bacterial community to detect fastidious/nonculturable organisms present among extubated ET tubes. We collected eight ET tubes with intubation periods between 12 h and 23 d from different patients in a surgical and a medical intensive care unit. Our qPCR data showed that ET tubes were colonized within 24 h. However, the variation between patients was too high to find a positive correlation between the bacterial load and intubation period. We obtained 1263 near full-length 16S rRNA gene sequences from the diverse bacterial communities. Over 70% of these sequences were associated with genera of typical oral flora, while only 6% were associated with gastrointestinal flora. The most common genus identified was Streptococcus (348/1263), followed by Prevotella (179/1263), and Neisseria (143/1263) with the highest relative concentrations for ET tubes with short intubation periods, indicating oral inoculation of the ET tubes. Our study also shows that even though potentially pathogenic bacteria existed in ET tube biofilms within 24 h of intubation, a longer intubation period increases the opportunity for these organisms to proliferate. In the ET tube that was in place for 23 d, 95% of the sequences belonged to Pseudomonas aeruginosa, which is a bacterial pathogen that is known to out compete commensal bacteria in biofilms, especially during periods of antibiotic treatment. Harboring such pathogens in ET biofilms may increase the chance of VAP, and should be aggressively monitored and prevented.
Authors' reply to “comments on Hilbert curve fractal antenna: A small resonant antenna for VHF/UHF applications”

© 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 35: 421, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10626
Erbe constant voltage electrocautery versus conventional variable voltage electrocautery for tonsillectomy in children

This prospective, randomized study was performed to compare postoperative pain, blood loss, and procedure time using the Erbe electrocautery device and conventional electrocautery. The Erbe device differs from conventional cautery devices in that it produces constant voltage and variable wattage whereas conventional devices produce variable voltage and constant wattage. This means that the conventional devices allow voltage surges and constant wattage no matter what type of tissue is encountered. The Erbe device has the inherent capability to maintain constant voltage, i.e. no surging as well as varying wattage according to tissue resistance. This, in theory, allows the Erbe device to impose less tissue damage and, theoretically, less postoperative pain. Fifty-seven patients 5-21 years of age who were scheduled for adenotonsillectomy were enrolled in the study. Results indicated less postoperative pain, although blood loss appeared to be increased compared to conventional electrocautery. The Erbe electrocautery device appears to be a viable device to perform tonsillectomy in children.
Disparities in timeliness of care for U.S. Medicare patients diagnosed with cancer

Background Timeliness of care (rapid initiation of treatment after definitive diagnosis) is a key component of high-quality cancer treatment. The present study evaluated factors influencing timeliness of care for U.S. Medicare enrollees. Methods Data for Medicare enrollees diagnosed with breast, colorectal, lung, or prostate cancer while living in U.S. seer (Surveillance, Epidemiology and End Results) regions in 2000–2002 were analyzed. Patients were classified as experiencing delayed treatment if the interval between diagnosis and treatment was greater than the 95th percentile for each cancer site. The impacts of patient sociodemographic, clinical, and area-based factors on the likelihood of delayed treatment were analyzed using multivariate logistic regression. Results Black patients (compared with white patients) and patients initially treated with radiation therapy or chemotherapy (rather than surgery) had a greater likelihood of treatment delays across all four cancer sites. Hispanic status, dual Medicare–Medicaid status, location of initial treatment (inpatient vs. outpatient), and stage at diagnosis also affected timeliness of care for some cancer sites. Surprisingly, area-based factors reflecting availability of cancer care services were not significantly associated with timeliness of care or were associated with greater delays in areas with greater numbers of service providers. Conclusions Multiple factors affected receipt of timely cancer care for members of the study population, all of whom had coverage of medical care services through Medicare. Because delays in treatment initiation can increase morbidity, decrease quality of life, shorten survival, and result in greater costs, prospective studies and tailored interventions are needed to address those factors among at-risk patient groups.
Video rate optical coherence tomography

We have developed an optical coherence tomography system which can image up to video rate. The system utilizes a high power broadband source and real time image acquisition hardware and features a high speed scanning delay line in the reference arm based on Fourier- transform pulse shaping technology. We detail the operation of the delay line and demonstrate real time imaging of in vivo human skin and Xenopus laevis embryo and in vitro samples of porcine gastrointestinal tissue
High throughput characterization of adult stem cells engineered for delivery of therapeutic factors for neuroprotective strategies.

Mesenchymal stem cells (MSCs) derived from bone marrow are a powerful cellular resource and have been used in numerous studies as potential candidates to develop strategies for treating a variety of diseases. The purpose of this study was to develop and characterize MSCs as cellular vehicles engineered for delivery of therapeutic factors as part of a neuroprotective strategy for rescuing the damaged or diseased nervous system. In this study we used mouse MSCs that were genetically modified using lentiviral vectors, which encoded brain-derived neurotrophic factor (BDNF) or glial cell-derived neurotrophic factor (GDNF), together with green fluorescent protein (GFP). Before proceeding with in vivo transplant studies it was important to characterize the engineered cells to determine whether or not the genetic modification altered aspects of normal cell behavior. Different culture substrates were examined for their ability to support cell adhesion, proliferation, survival, and cell migration of the four subpopulations of engineered MSCs. High content screening (HCS) was conducted and image analysis performed. Substrates examined included: poly-L-lysine, fibronectin, collagen type I, laminin, entactin-collagen IV-laminin (ECL). Ki67 immunolabeling was used to investigate cell proliferation and Propidium Iodide staining was used to investigate cell viability. Time-lapse imaging was conducted using a transmitted light/environmental chamber system on the high content screening system. Our results demonstrated that the different subpopulations of the genetically modified MSCs displayed similar behaviors that were in general comparable to that of the original, non-modified MSCs. The influence of different culture substrates on cell growth and cell migration was not dramatically different between groups comparing the different MSC subtypes, as well as culture substrates. This study provides an experimental strategy to rapidly characterize engineered stem cells and their behaviors before their application in longterm in vivo transplant studies for nervous system rescue and repair.
In Vivo Internet Computing: Bionic Web Surfing

More closely integrating Internet computing with daily activities could significantly affect overall Internet workloads. This isuue discusses Internet performance as it relates to current research issues.
Asthma and obesity in three-year-old urban children: role of sex and home environment.

Objective To examine whether the relationship between obesity and asthma in young girls and boys can be explained by social and physical characteristics of the home environment. Study design We examined the relationship between asthma and obesity in children in the Fragile Families and Child Wellbeing Study (n = 1815). Asthma was determined through maternal report of asthma diagnosis by a doctor (active in past 12 months). Weight and height of child was measured during an in-home visit. Data on home social (maternal depression, intimate partner violence) and physical environmental factors (housing quality, tobacco exposure) were collected via questionnaire. Results Ten percent of children had active asthma, 19% of children were overweight, and 17% of children were obese. In fully adjusted models, obese children had twice the odds of having asthma (OR, 2.3; 95% CI, 1.5-3.3) compared with children of normal body weight. In stratified analyses, overweight boys, but not overweight girls, had increased of odds of asthma. Obese boys and girls had increased odds of asthma compared with boys and girls of normal body weight. Conclusion The relationship between asthma and obesity is present in boys and girls as young as 3 years of age; a relationship between being overweight and asthma is only present among boys. This relationship is not attributable to shared social and environmental factors of the children's home.
THE GEOMETRIC MEAN OF THE AGE-SPECIFIC DEATH RATES AS A SUMMARY INDEX OF MORTALITY

Even though a single summary index of mortality can never replace the set of age-specific death rates, it has been found to be extremely useful for a wide variety of purposes. Such indexes are generally one of two types: aggregative indexes, such as directly standardized rates which reflect absolute differences between corresponding age-specific mortality rates; and average of relatives indexes which reflect proportional differences between those rates. The choice of index depends upon the purposes for which it is to be used, and is important as different indexes can produce very different results. While directly standardized rates are widely used, they depend upon the selection of an appropriate standard population and give disproportionately heavy weight to the high ages. Average of relatives indexes give equal weight to all ages, but are infrequently used as no index of that type has gained wide acceptability. This paper recommends the use of the geometric mean of the age-specific mortality rates as such an index, and shows that this index is readily calculable, unbiased, needs no standard population, is directly comparable to all other indexes so calculated, and accurately reflects exponential mortality patterns.
Processive ubiquitin chain formation by the anaphase-promoting complex

Progression through mitosis requires the sequential ubiquitination of cell cycle regulators by the anaphase-promoting complex, resulting in their proteasomal degradation. Although several mechanisms contribute to APC/C regulation during mitosis, the APC/C is able to discriminate between its many substrates by exploiting differences in the processivity of ubiquitin chain assembly. Here, we discuss how the APC/C achieves processive ubiquitin chain formation to trigger the sequential degradation of cell cycle regulators during mitosis.
Simultaneous shotgun sequencing of multiple cDNA clones

This study describes an efficient method for the rapid sequencing of DNA fragments in the size range 1–5 kb. Individual fragments, here cDNA inserts, are purified by restriction enzyme digestion and gel purification, pooled and concatenated by ligation. The concatamers are sheared and cloned randomly into M13, followed by random sequencing. The sequences of the individual cDNA inserts are obtained at the assembly stage using restriction enzyme sites as ‘tags’ for the ends of each fragment. In this study the sequencing of two libraries containing 7 and 16 cDNA inserts with an average length of 2.5 kb is described. The results show that the efficiency of the procedure is comparable to that of the shotgun sequencing of large fragments, and that the method compares favorably to alternative strategies, such as primer walking.
Theorizing Native American Land Seizure: An Analysis of Tactical Changes in the Late Twentieth Century

This paper advances the existing literature on tactics by analyzing the persistence of land seizure as a particular strategy in Native American political activism over five decades. It examines the different types of spaces seized and the claims made during three distinct historical periods: public spaces on reservations during the recuperative phase (1950–69), surplus federal lands away from reservations during the expropriative phase (1969–75), and high-profile locales on and off tribal lands during the demonstrative phase (1975–2000). Land seizures were often means to make material demands or articulate normative claims, but always served to complicate the state's exercise of power over Native peoples. Through case studies the paper demonstrates how spatial disruption, resource availability, and dynamism affected the continued viability of land seizure as a tactic to advance Native Americans' political demands.
Defect-free 50-layer strain-balanced InAs quantum dots grown on InAlGaAs/InP for infrared photodetector applications

We present a strain-balanced InAs quantum dot (QD) system that has great potential in fabricating high-performance multilayer QD infrared photodetector structures. The overall compressive strain caused by the formation of InAs QDs on InAlGaAs/InP is successfully balanced by inserting tensile-strained InGaAs layers immediately above QD layers. The strain-balanced QD structure allows stacking a large number of defect-free QD layers for increasing the size uniformity of QDs as well as the optical absorption, which are essential to the high-performance photodetector. As the first step toward the demonstration of a high-performance photodetector, a 50-layer strain-balanced InAs QD structure was grown. No visible defect was detected from the cross-sectional transmission electron microscopy measurements. In addition, the intense and narrow linewidth of the room temperature photoluminescence spectrum indicate a good optical quality of the structure.
Analysis of the growth of strike-slip faults using effective medium theory

Increases in the dimensions of strike-slip faults including fault length, thickness of fault rock and the surrounding damage zone collectively provide quantitative definition of fault growth and are commonly measured in terms of the maximum fault slip. The field observations indicate that a common mechanism for fault growth in the brittle upper crust is fault lengthening by linkage and coalescence of neighboring fault segments or strands, and fault rock-zone widening into highly fractured inner damage zone via cataclastic deformation. The most important underlying mechanical reason in both cases is prior weakening of the rocks surrounding a fault's core and between neighboring fault segments by faulting-related fractures. In this paper, using field observations together with effective medium models, we analyze the reduction in the effective elastic properties of rock in terms of density of the fault-related brittle fractures and fracture intersection angles controlled primarily by the splay angles. Fracture densities or equivalent fracture spacing values corresponding to the vanishing Young's, shear, and quasi-pure shear moduli were obtained by extrapolation from the calculated range of these parameters. The fracture densities or the equivalent spacing values obtained using this method compare well with the field data measured along scan lines across the faults in the study area. These findings should be helpful for a better understanding of the fracture density/spacing distribution around faults and the transition from discrete fracturing to cataclastic deformation associated with fault growth and the related instabilities.
Isolation of thymosin α1 from thymosin fraction 5 of different species by high-performance liquid chromatography

High-performance liquid chromatography (muBondapak C18 column with 0.05% trifluoroacetic acid in acetonitrile as solvent system) was used to isolate thymosin alpha 1 (alpha 1) from thymosin fraction 5 (f5) of various species (calf, pig, sheep and mouse). Each of the f5 preparations gave a protein peak similar in retention time to bovine thymosin alpha 1. This peak coincided with the immunoreactive peak determined by a radioimmunoassay for alpha 1. Chromatographic analysis of fresh thymus tissue extracts using a high-performance liquid chromatographic similar system did not reveal a detectable protein peak or immunoreactive peak at the alpha 1 position. Our results suggest that alpha 1 may be synthesized in a precursor form in animal tissues.
Virtual Reference and Boundary Talk: Joining Conversations Already in Progress

(1999). Virtual Reference and Boundary Talk: Joining Conversations Already in Progress. Journal of the Learning Sciences: Vol. 8, No. 3-4, pp. 509-516.
An efficient spectral domain method of moments for Reflectarray antennas using a customized impedance matrix interpolation scheme

The acceleration method to be presented is a novel interpolation of the impedance matrix elements over patch size thereby reducing the number of moment method runs needed in the parameter sweep used to generate the design curves. In the Reflectarray antenna design process, the spherical angles in the plane of incidence, formed by the unit normal vector of the ith patch and the incident k vector emanating from the feed phase center to the ith patch centroid, are unique to each and every element of the Reflectarray. Thus, each and every element demands a unique design curve. For electrically large Reflectarray antennas, say on the order of thousands of elements, this would be a tremendous undertaking using the popular commercially available tools such as HFSS or CST MWS. Even with an in-house developed code based upon the standard SDMoM algorithm, this would still require many hours and possibly days. Also, if one were given a set of requirements that must be met simultaneously, an often popular approach would be to choose global optimizers such as PSO or GA, and if the evaluation of the cost function took hours or days for each evaluation, then this strategy would be unfeasible. There exists, therefore, a strong desire to accelerate the standard SDMoM algorithm to an extremely rapid pace, on the order of seconds to minutes in lieu of hours to days. This is possible using the Z-matrix Interpolation scheme as presented in this talk.
Advocacy: Changing Our Professional Behaviors

(2000). Advocacy: Changing Our Professional Behaviors. Journal of Physical Education, Recreation & Dance: Vol. 71, No. 3, pp. 46-49.
A Planar, Chip-Based, Dual-Beam Refractometer Using an Integrated Organic Light-Emitting Diode (OLED) Light Source and Organic Photovoltaic (OPV) Detectors

We present a simple chip-based refractometer with a central organic light-emitting diode (OLED) light source and two opposed organic photovoltaic (OPV) detectors on an internal reflection element (IRE) substrate, creating a true dual-beam sensor platform. For first-generation platforms, we demonstrate the use of a single heterojunction OLED based on electroluminescence from an Alq3/TPD heterojunction (tris-(8-hydroxyquinoline)aluminum/N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine) and light detection with planar heterojunction pentacene/C60 OPVs. The sensor utilizes the considerable fraction of emitted light from conventional thin-film OLEDs that is coupled into guided modes in the IRE, instead of into the forward (display) direction. A ray-optics description is used to describe light throughput and efficiency-limiting factors for light coupling from the OLED into the substrate modes, light traversing through the IRE substrate, and light coupling into the OPV detectors. The arrangement of the OLED at th...
Neuronal correlates of inferred motion in primate posterior parietal cortex.

FOR many types of behaviours, it is necessary to monitor the position or movement of objects that are temporarily occluded. The primate posterior parietal cortex contains neurons that are active during visual guidance tasks: in some cases, even if the visual target disappears transiently1,2. It has been proposed that activity of this sort could be related to current or planned eye movements1,2, but it might also provide a more generalized abstract representation of the spatial disposition of targets, even when they are not visible. We have recorded from monkey posterior parietal cortex while the animal viewed a visual stimulus that disappeared, and then, depending on experimental context, could be inferred to be either moving or stationary. During this temporary absence of the stimulus, about half of the neurons were found to be significantly more active on those trials in which the stimulus could be presumed to be moving rather than stationary. The activity was thus present in the absence of either sensory input or motor output, suggesting that it may indeed constitute a generalized representation of target motion.
The specificity of active-site alkylation by iodoacetic acid in the enzyme thiosulfate sulfurtransferase

The active-site sulfhydryl group in the enzyme thiosulfate sulfurtransferase (rhodanese; thiosulfate:cyanide sulfurtransferase; EC 2.8.1.1) is alkylated rapidly by iodoacetic acid in the free enzyme form, E, with complete loss of sulfurtransferase activity. Iodoacetic acid is completely ineffective with the sulfur-substituted form of the enzyme, ES. Iodoacetamide, on the other hand, has no effect on either enzyme form. The competitive enzyme inhibitor, toluenesulfonic acid, protects against inactivation in a strictly competitive way and analysis gives an apparent binding constant for toluenesulfonic acid of 12.5 mM, which is in agreement with studies of its effect on the catalyzed reaction. These results are taken to indicate that iodoacetic acid is an affinity analog for the substrate, thiosulfate, and inactivates because it can use the specific thiosulfate binding interactions, correctly orient its reactive center and displace intraprotein interactions which appear to protect the active-site sulfhydryl group in the E form.
Equity for Black Americans in precollege science

The purpose of this article is to explore many of the experiences that Black Americans have in science education in the United States and propose changes so that Black Americans have an equitable opportunity to engage in and learn quality science. The outcome of quality science is the possession of science knowledge and skills of Black American students to either maintain or change their world as they choose. Science for All Americans delineates the themes and habits of minds that scientifically literate high school graduates should possess; however, these are the preparatory fundamentals for Black American students if equity is to exist for them in science education. Equity in science learning, science teaching, science schooling practices, and quality science opportunities are discussed. The science learning of Black American students continue to be championed; however, the debate persists on the efficiency of culturally relevant science learning. The instruction of many impoverished rural and urban Black American students is very inadequate because of low teacher expectation, inadequate science knowledge and skills of teachers, teachers' poorly clarified professional and cultural beliefs and values, and science curricula that do not focus on the knowledge and skills outlined in Science for All Americans. Some progress toward schooling practices has occurred; however, few have been implemented long enough to determine their impact on Black Americans' science learning. Proposed solutions aimed at providing equitable opportunities for all students to learn quality science include preparing multicultural science teachers, eliminating tracking in schools, equipping classes with science curriculum materials and technology, and supplying financial resources. © 2000 John Wiley & Sons, Inc. Sci Ed84:154–179, 2000.
Stochastic fluid flow models for determining optimal switching thresholds

This paper is motivated by the problem of capturing and releasing the CPU by a routine software application in order to accommodate other non-routine requests that need the CPU. Specifically, we consider a network of distributed software agents where each agent is assigned with routine tasks that need to be processed by a CPU. The CPU also receives requests from other processes running on the machine. The problem is to select an optimal threshold on the workload of the agent so that the agent releases the CPU and recaptures it from time-to-time based on its workload.In order to do that, we use a stochastic fluid-flow model with two buffers, one for the agent that runs the routine tasks and the other for the remaining non-routine jobs at the CPU. Input to the two buffers are from on-off sources and the processor switches between the two buffers using a threshold-based policy. We develop analytical approximations for the buffer content distribution and determine the Quality of Service (QoS) experienced by the two sources of traffic. We use the QoS performance measures to formulate and solve an optimization problem to design an optimal threshold value.
An improved method for the nondestructive assay of the tritium content of glass microballoon laser fusion targets

In laser fusion experiments employing deuterium-tritium filled microballoons, it is essential that the fill pressure be known for each target prior to its use. While most targets retain their original fill pressure (5–50 atm) indefinitely when stored at liquid nitrogen temperature, some leakage has been observed in random samples. Since we have found that tritium and deuterium leak from glass microballoons at essentially the same rates, a measurement of only the tritium content is sufficient to characterize completely the target fill. The tritium content is determined by measuring the flux ofβ particles (from the decay of tritium) which emerge from the target wall. To relate this flux to the target fill pressure, a model has been developed based upon a Monte Carlo simulation of the transport of theβ particles through the target's gaseous interior and glass wall. The model is incorporated into an accurate and self-consistent procedure for the nondestructive determination of the tritium content of laser fusion targets with a wide range of radii and wall thicknesses. This paper contains a detailed description of the model, and its implementation for assaying the fuel content in such targets. Also included is a discussion of how to compensate for the counts due to tritium trapped in the shell material. This correction is especially important when the target walls are thicker than 3μm when the shell diameters lie in the range 50–300μm. Limitations of this procedure, associated errors, and general guidelines are provided in order to indicate when this technique may be preferable over alternate methods, such as x-ray counting.
Strong shift equivalence of 2 × 2 matrices of non-negative integers

The concept of strong shift equivalence of square non-negative integral matrices has been used by R. F. Williams to characterize topological isomorphism of the associated topological Markov chains. However, not much has been known about sufficient conditions for strong shift equivalence even for 2×2 matrices (other than those of unit determinant). The main theorem of this paper is: If A and B are positive 2×2 integral matrices of non-negative determinant and are similar over the integers, then A and B are strongly shift equivalent.
Levee scour from overtopping storm waves and scour counter measures

Laboratory wavetank experiments were performed on the landside levee scour induced by floodwall overtopping. The objectives of this study were to elucidate the landside levee scour characteristics and evaluate the effectiveness of selected scour counter measures. Model levees, both with and without a scour protection measure, were constructed. Four scour protection armoring were tested: riprap, coreloc, riprap with an underlayer, and coreloc with an underlayer. The levee soil was composed of a sand-clay mixture. The geometric scour characteristics of interest driven by their practical importance were maximum scour depth and scour length. Both the maximum scour depth and the scour length exhibited an exponential trend in approaching equilibrium values, with the scour length reaching equilibrium sooner. Parameterizations for predicting the values of the maximum scour depth and length while approaching the equilibrium and at the equilibrium state were developed. Though the riprap armoring cover proved more effective than the coreloc armoring cover, the presence of an armoring underlayer was a greater impetus of the overall effectiveness of both protection measure types. Therefore, it is recommended that the placement and size distribution of the underlayer be adjusted in the field accordingly for the greatest disaster prevention and economic advantage.