cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural and dielectric properties of Sr 2 TiO 4 from first principles

We have investigated the structural and dielectric properties of Sr 2 TiO 4 , the first member of the Sr n + 1 Ti n O 3 n + 1 Ruddlesden-Popper series, within density-functional theory. Motivated by recent work in which thin films of Sr 2 TiO 4 were grown by molecular beam epitaxy on SrTiO 3 substrates, the in-plane lattice parameter was fixed to the theoretically optimized lattice constant of cubic SrTiO 3 (n=∞), while the out-of-plane lattice parameter and the internal structural parameters were relaxed. The fully relaxed structure was also investigated. Density-functional perturbation theory was used to calculate the zone-center phonon frequencies, Born effective charges, and the electronic dielectric permittivity tensor. A detailed study of the contribution of individual infrared-active modes to the static dielectric permittivity tensor was performed. The calculated Raman and infrared phonon frequencies were found to be in agreement with experiment where available. Comparisons of the calculated static dielectric permittivity with experiments on both ceramic powders and epitaxial thin films are discussed.
The Ancient World

From the dawn of recorded history, man has watched the skies above him, marveling at their mysteries and wondering about the myriads of stars that seem to be embedded, like tiny gems, in the celestial dome. What are those stars made of? How far are they? What message do they have for us? Questions such as these, inspired by man’s awe at the grandeur of the creation, were the first step in the creation of a science of the heavens, astronomy. It is a paradoxical fact that astronomy, which studies the farthest objects we can think of, was the first discipline of knowledge to become a full-fledged science in the modern sense of the word. Compare this with geology or biology—the disciplines concerned with our planet and its inhabitants—which emerged as true sciences only in the past few centuries. It seems that the farther a mystery lies, the greater the urge to solve it!
Extracellular RNA Activates Neutrophils via Toll-like Receptor 7

Objective:We have recently reported that extracellular RNA (exRNA) released from necrotic cells induces cytokines production in cardiomyocytes (CM) and may play a role in a mouse model of myocardial ischemia-reperfusion injury. However, whether exRNA has any effect on neutrophils (NE) and how it works is unclear. Methods: Mouse peritoneal NEs were treated with RNA (2.5 – 10 µg/ml) purified from mouse heart or rat CM. Cytokine mRNA at 3 h and proteins at 18 h were measured by qRT-PCR and ELISA, respectively. WT mice were injected i.p. with 50 µg of the purified RNA. Six h later, the peritoneal lavage was harvested and centrifuged. The supernatants were measured for cytokines production. The peritoneal cells were counted and NE gated with Ly-6G. ROS generation and CD11b expression in NE were measured by flow cytometry. Results: exRNA induced MIP-2 production in a dose-dependent manner. The effect was completely diminished by RNase, but not DNase. Moreover, the exRNA-induced cytokine production in NE was nea...
The Effect of Inconsistency on Evaluations of a Second Eyewitness: It Depends On Who Testifies First

Research has investigated how jurors perceive lone eyewitness testimony. However, little research exists on jurors' perceptions of cases involving multiple witnesses. Two experiments examined how contrast effects influence judgments in cases with two witnesses. After reading testimony from an inconsistent or consistent witness, participants rated the credibility and accuracy of a target second witness who displayed either consistency or inconsistency. Both experiments showed that the first witness's consistency affected perceptions of a target second witness. When the target witness testified after another witness exhibiting the same level of consistency, participants perceived an inconsistent target witness as less coherent, credible, and accurate than a consistent target witness. However, when the target witness followed a witness demonstrating a different level of consistency, participants differentiated even more between a consistent and inconsistent target witness. These contrast effects also influen...
Facts and Norms in Policy Scholarship

Policy debates are fundamentally debates about what to do and so require both factual and normative premises. Empirical policy researchers, especially when engaged in investigations that do not issue explicit policy recommendations, might prefer to think that their analyses avoid normative commitments, at least controversial ones. Ethicists and social philosophers who pass judgment on social policies may believe that their analyses rely on only noncontroversial empirical premises. Both parties are mistaken. Policy scholars often depend on tacit normative commitments that are problematic. Philosophers often help themselves to empirical premises which are more matters of faith than confirmed fact. The former point, to which I turn briefly, is the more familiar, but the latter raises important questions less often discussed.
Species Diversity and Functional Composition of Pastures that Vary in Landscape Position and Grazing Management

The productivity of grasslands depends in part on their diversity of species and functional composition. Our objective was to examine the effects of three landscape positions (summit, backslope, and toeslope) and three stocking systems (continuous, rotational, and nongrazed) on species diversity and percentage of cover of grass, legume, and weed species functional types in southeastern Iowa pastures. Data were collected in 0.2-m 2 plots randomly distributed throughout each of four replicate pastures in spring and summer 2000 and 2001. Backslope landscape positions within pastures managed with either continuous or rotational stocking contained the greatest overall diversity of species. Across years, overall species richness under grazing averaged 4.8 on backslopes, 3.5 on summits, and 2.9 on toeslopes. Legume cover was greatest within the rotational stocking system, averaging 21% on backslopes, 10% on summits, and 3% on toeslopes across years. Cool-season grasses dominated summits and toeslopes, consisting of 88 to 94% of the cover. Weed species diversity and cover were greatest on backslopes within the continuous stocking system. Our results showed that rotational stocking had more desirable effects through greater legume cover and less weed cover on backslopes than continuous stocking. This research suggested that spatial components of pastures should be considered to optimize the production and quality of forage for grazing livestock.
A fabrication process with high thermal isolation and vacuum sealed lead transfer for gas reactors and sampling microsystems

This paper describes a six-mask fabrication process for vacuum-sealed microsystems including pressure and flow sensors, reaction chambers and reservoirs, and channels ranging from 100 nm to 10 /spl mu/m in hydraulic diameter. All structures are countersunk into a glass substrate, resulting in a planar upper surface that eliminates stress concentrations and also facilitates further lithographic processing. The material choices and structural arrangements are designed to. provide high thermal isolation (/spl sim/2 /spl times/ 10/sup 5/ K/W). Lead transfer between the three available levels of interconnect are accomplished with minimal parasitic capacitance (< 1 fF), and low resistance (/spl sim/1 /spl Omega/). A variety of test structures have been successfully fabricated.
HIF-1 promotes invasion and metastasis of head and neck squamous cell carcinoma.

Proc Amer Assoc Cancer Res, Volume 47, 2006 5143 Cells capable of adapting to hypoxia and hypoglycemia have a selective advantage in the head and neck squamous cell carcinoma (HNSCC) microenvironment of, where oxygen and nutrient requirements rapidly exceed the vascular supply. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor responsible for up-regulating the expression of many adaptive genes. Under normal oxygen conditions, HIF-1 activity is minimized due to proteasomal degradation of the HIF-1α subunit. Dysregulation of HIF-1α expression within adapting HNSCC cells may lead to increased malignant behavior. Basal expression of HIF-1α in cell lines derived from metastatic disease (e.g. UM-22B) is increased compared to expression in cell lines derived from the primary tumor of the same patient (e.g. UM-22A). Under normal oxygen conditions, Matrigel™ invasion is increased in UM-22B cells compared to UM-22A cells. Expression of a degradation-resistant HIF-1α mutant (HIF-1α/P564A) in either of these cell lines causes an increase in malignant behavior. Under both normal and low oxygen conditions, in vitro transcriptional activity of HIF-1 is increased as measured by a luciferase assay. Matrigel™ invasion is significantly increased in the HIF-1α/P564A cell lines as compared to their respective controls (p=0.014). In an athymic nude mouse xenograft model, UM-22A cells rarely metastasize from the floor of mouth to the cervical lymph nodes (1/11; 9.1%). UM-22A/HIF-1α/P564A metastasized significantly more often (7/12; 58.3%; p=0.027). Gene-expression profiles of HIF-1α/P564A cells under normal oxygen conditions and parental cells under hypoxic conditions revealed potential candidate proteins that may facilitate HNSCC invasion and metastasis. Thus, HIF-1 expression is sufficient to increase the invasive and metastatic ability of HNSCC cells in vitro and in vivo . Additionally, adaptive genes that have similar altered expression levels in the presence of increased HIF-1 or hypoxia may be critical for HNSCC invasion and metastasis.
A Comparison of MPICH Allgather Algorithms on Switched Networks

This study evaluates the performance of MPI_Allgather() in MPICH 1.2.5 on a Linux cluster. This implementation of MPICH improves on the performance of allgather compared to previous versions by using a recursive doubling algorithm. We have developed a dissemination allgather based on the dissemination barrier algorithm. This algorithm takes log2 p stages for any values of p. We experimentally evaluate MPICH allgather and our implementations on a Linux cluster of dual-processor nodes using both TCP over FastEthernet and GM over Myrinet. We show that on Myrinet, variations of the dissemination algorithm perform best for both large and small messages. However, when using TCP, the dissemination allgather algorithm performs poorly because data is not exchanged in a pair-wise fashion. Therefore, we recommend the dissemination allgather for low-latency switched networks.
The influence of video imaging on patients' perceptions and expectations

Seventy-four patients, ranging in age from 15 to 50 and presenting with a moderate to severe dentofacial deformity requiring orthognathic surgery, were randomly assigned to a video imaging or a standard case presentation (CP) group. Motives for treatment did not differ significantly between the video image and standard CP groups. Two weeks after the case presentation, 60% of the standard CP group and 74% of the video image group ranked the anticipated change in facial appearance as an important factor in making a treatment decision. Seventy percent of the standard CP group and 83% of the video image group agreed with the statement that surgery would be necessary to correct their problem. In the standard CP group, 47% of the patients ranked dental casts as the most helpful physical record in making a treatment decision, and 46% said the acetate profile tracing was the most helpful tool for understanding what to expect from treatment. In the video imaging group, 42% of the patients said the video imaging presentation was the most helpful tool in making a treatment decision, and 39% of the patients said it was the most helpful tool for understanding treatment expectations. The proportion of patients in the video image case presentation group with elevated self-image expectations following treatment was significantly higher (P = .045) than in the standard case presentation group. The presentation of video images appears to be a valuable information source for conveying treatment options to patients, but caution may be needed to prevent elevated or possibly unrealistic treatment expectations.
FLIBE Chemistry Studies

A 2:1 mixture of LiF and BeF{sub 2} (FLIBE), is a potential tritium breeder material for fusion reactors, in particular, the Advanced Safe Pool Immersed Reactor (ASPIRE). A limited experimental campaign was conducted in an effort to test the postulates of the ASPIRE concept: namely, that MoF{sub 6} is effective in controlling the tritium species by maintaining the FT form and that MoF{sub 6} can serve as a source to plate out Mo on surfaces, thereby making the FLIBE system compatible with the corrosive FT. It was demonstrated experimentally that successive additions of MoF{sub 6} achieved quantitative (i.e., greater than 99.7%) conversion of H{sub 2} to HF. Thus, MoF{sub 6} is effective in controlling the tritium species. The degree of conversion of H{sub 2} to H demonstrates that H does not attack MO to form H{sub 2}. This supports the postulate that the system is compatible with Mo. Thus, if it were possible to plate out and maintain a coating of Mo on all surfaces in contact with the FLIBE system, the ASPIRE concept could work. Thermodynamic calculations also confirmed that MoF{sub 6} should be capable of quantitatively (>99.9%) converting H{sub 2} to HF. There is both experimental and theoretical more » evidence that a number of MoF{sub x} species are present in both the gas phase and the FLIBE solution. 17 refs., 3 figs., 3 tabs. « less
RETENTION OF VITAMINS IN FRESH AND FROZEN BROCCOLI PREPARED BY DIFFERENT COOKING METHODS

Fresh and frozen broccoli were analyzed for retention of ascorbic acid, riboflavin and thiamine by semi-automated fluorometry before and after steaming, boiling or microwave cooking for 5 min. Retention of vitamins in general was higher for fresh than for frozen broccoli. Steamed fresh broccoli retained most ascorbic acid, riboflavin, and thiamine. Boiled fresh samples retained least riboflavin and ascorbic acid and microwaved samples, the least thiamine. In frozen broccoli, microwaved samples retained most ascorbic acid and riboflavin, and steamed samples retained most thiamine.
Effects of a Fall Drawdown on Movement of Adult Northern Pike and Largemouth Bass

Abstract Adult northern pike Esox lucius and largemouth bass Micropterus salmoides were monitored with ultrasonic transmitters in two 25-ha lakes in Colorado to evaluate the effect of water level drawdown on movement. Water levels in one lake were reduced from September through November, whereas an adjacent lake was held at full pool levels. Largemouth bass in the treatment lake moved greater distances and exhibited larger 24-h use areas during drawdown conditions. Increases in movement and use areas by northern pike associated with low water levels were not significantly different from those at full pool levels. Movement of largemouth bass and northern pike in the stable lake remained constant throughout the study. These results suggest that water level fluctuations may alter predator behavior.
Marxism, Leninism, and Soviet Communism

Leopold H. Haimson, The Russian Marxists and the Origins of Bolshevism Cambridge, Mass., Harvard University Press, I955, 246 pp. $5.50. Donald W. Treadgold, Lenin and His Rivals: The Struggle for Russia's Future, 1898-1g06, New York, Frederick A. Praeger, I955, 29I pp. $5.00. Leonard Schapiro, The Origin of the Communist Autocracy: Political Opposition in the Soviet State-First Phase, I9I7-I922, Cambridge, Mass., Harvard University Press, I955, 397 pp. $7.00. Georg von Rauch, A History of Soviet Russia, trans. by Peter and Annette Jacobsohn, New York, Frederick A. Praeger, I957, 493 pp. $6.75. Henri Chambre, Le Marxisme en Union Sovietique. Ideologie et Institutions: Leur Ivolution de I9I7 a nos Jours, Paris, Jiditions du Seuil, I955, 5I0 pp. I200 fr. Raymond A. Bauer, Alex Inkeles, and Clyde Kluckhohn, How the Soviet System Works: Cultural, Psychological, and Social Themes, Cambridge, Mass., Harvard University Press, i956, 274 pp. $4.75. Alf Edeen, Rysslands Nya Medelklass (Skrifter utgivna av Utrikespolitiska Institutet, No. 8), Stockholm, Kooperativa F6rbundets Bokforlag, I954, I04 pp. Kr. 5.50.
Endocytic control of epithelial polarity and proliferation in Drosophila

Intracellular protein transport is a key factor in epithelial cell polarity. Here we report that mutations in two core components of the vesicle trafficking machinery — a syntaxin and a Rab protein — cause an expansion of the apical membrane domain of Drosophila melanogaster epithelia; this polarity defect is coupled with overproliferation to form neoplastic tumours. Surprisingly, these proteins are associated with the endocytic, and not the exocytic, pathway. The syntaxin Avalanche (Avl) localizes to early endosomes, and loss of avl results in the cellular accumulation of specific membrane proteins, including the Notch signalling receptor and the polarity determinant Crumbs (Crb). Protein accumulation results from a failure in endosomal entry and progression towards lysosomal degradation; these and other avl phenotypes are also detected in Rab5 null mutant cells. Overexpression of Crb alone is sufficient to induce overproliferation of wild-type imaginal tissue, suggesting that polarity alterations in avl and Rab5 mutants directly contribute to tumour formation. Our findings reveal a critical and specific role for endocytic traffic in the control of both apico-basal polarity and cell proliferation.
The Dissolution of Ethical Decision-Making in Organizations: A Comprehensive Review and Model

The purpose of this research is to present the major factors that lead to ethical dissolution in an organization. Specifically, drawing from a wide spectrum of sources, this study explores the impact of organizational, individual, and contextual factors that converge to contribute to ethical dissolution. Acknowledging that ethical decisions are, in the final analysis, made by individuals, this study presents a model of ethical dissolution that gives insight into how a variety of elements coalesce to draw individuals into decisions that result in the ethical undoing of an otherwise healthy organization. ENRON, TYCO and WorldCom did not happen in a vacuum. Nor can such debacles be explained as simply one or two individuals who were morally corrupt. The ethical breakdowns that occurred in these companies happened over a period of time, involved numerous individuals both inside and outside of the organization, and brought about the implosion of viable companies. Seeking to extend the work of previous researchers, this study attempts to tie together a disparate set of factors into a cohesive explanation of ethical breakdowns in organizations.
Systemic lipopolysaccharide plus MPTP as a model of dopamine loss and gait instability in C57Bl/6J mice.

In most environmental models of Parkinson's disease (PD), a single neurodegenerative agent is introduced to cause nigrostriatal dopamine depletion. However, cell loss in human PD often might derive, at least in part, from multiple toxins or vulnerabilities, any one of which alone does not inevitably lead to chronic dopamine depletion. In the present research, male C57BL/6J mice were systemically administered the inflammatory bacterial endotoxin, lipopolysaccharide (LPS) and the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) alone or in combination and the behavior as well as striatal dopamine levels were compared to saline-treated mice. Mice in the combination (LPS + MPTP) group, but not in the single-factor groups, showed both dopamine depletion and parkinsonian symptoms, i.e., reduced stride length, at 4 months post-injection. MPTP alone acutely reduced striatal dopamine levels but this effect was transient as striatal dopamine recovered to normal levels after time (4 months). The LPS-only group showed no dopamine depletion or reduced stride length. These data are consistent with the view that nigrostriatal dopamine neurons might succumb after time to multiple toxic agents that independently may have only a transient, adverse effect.
Distinction between Atropine-Sensitive Control of Microvascular and Cardiac Oscillatory Activity

Abstract This study tested whether “high frequency” oscillations (HF; >0.12 cycles/s) in microvascular flow during a vasoconstrictive challenge constitute a homeostatic cholinergic response at the level of the microvasculature or simply represent oscillations that originate at the heart and are transmitted to passive microvascular beds. Heart rate, blood pressure, respiratory rate, and laser Doppler flowmetry of the forehead and finger were monitored in healthy volunteers at baseline, during systemic infusion of phenylephrine (0.4–0.6 μg/kg/min), and during subsequent addition of intravenous atropine (≤2.0 mg/70 kg). Spectral-domain analysis documented that atropine-sensitive oscillatory power of the R-wave to R-wave intervals of the electrocardiogram was predominant at the respiratory frequency (0.20 Hz) at baseline and during phenylephrine infusion. In contrast, arteriolar–capillary networks of the forehead developed a prominent atropine-sensitive oscillatory peak at 0.14 ± 0.02 Hz during phenylephrine infusion (P
Wavelet-based polarimetry analysis

Wavelet transformation has become a cutting edge and promising approach in the field of image and signal processing. A wavelet is a waveform of effectively limited duration that has an average value of zero. Wavelet analysis is done by breaking up the signal into shifted and scaled versions of the original signal. The key advantage of a wavelet is that it is capable of revealing smaller changes, trends, and breakdown points that are not revealed by other techniques such as Fourier analysis. The phenomenon of polarization has been studied for quite some time and is a very useful tool for target detection and tracking. Long Wave Infrared (LWIR) polarization is beneficial for detecting camouflaged objects and is a useful approach when identifying and distinguishing manmade objects from natural clutter. In addition, the Stokes Polarization Parameters, which are calculated from 0°, 45°, 90°, 135° right circular, and left circular intensity measurements, provide spatial orientations of target features and suppress natural features. In this paper, we propose a wavelet-based polarimetry analysis (WPA) method to analyze Long Wave Infrared Polarimetry Imagery to discriminate targets such as dismounts and vehicles from background clutter. These parameters can be used for image thresholding and segmentation. Experimental results show the wavelet-based polarimetry analysis is efficient and can be used in a wide range of applications such as change detection, shape extraction, target recognition, and feature-aided tracking.
Dopamine-mediated actions of ephedrine in the rat substantia nigra

Abstract Although ephedrine is a centrally active stimulant, its effect on midbrain dopamine neurons is not known. To study the effect of ephedrine on dopamine-containing cells, current-clamp microelectrode recordings were made from substantia nigra pars compacta (SNC) neurons in horizontal brain slice preparations. Ephedrine (100–1000 μM) slowed spontaneous firing and produced a modest concentration-dependent hyperpolarization of membrane potential (EC50 279 μM), with a concomitant net decrease in membrane resistance. These effects were blocked by the D2-like dopamine antagonist sulpiride (1 μM). Electrically evoked inhibitory synaptic potentials mediated by GABAB receptors were reduced 28% by ephedrine. However, ephedrine did not reduce fast synaptic potentials mediated by GABAA or ionotropic glutamate receptors. Inhibition of the GABAB response appeared to be mediated by a postsynaptic mechanism because ephedrine also reduced baclofen-induced hyperpolarization by 28%. Both ephedrine-induced hyperpolarization and inhibition of baclofen-induced hyperpolarization were abolished when slices were superfused with the tyrosine hydroxylase inhibitor α-methyl-para-tyrosine (AMPT). Despite perfusion with AMPT, the ability of ephedrine to cause hyperpolarization was restored after perfusing the slice with dopamine (30 μM). Taken together, these results suggest that ephedrine causes hyperpolarization and suppresses GABAB receptor-mediated effects by releasing endogenous dopamine. However, the high concentrations required to observe these effects in vitro suggest that biologically relevant central effects of ephedrine are more likely to be mediated either by non-dopamine systems, such as those involving noradrenaline, or by dopamine systems outside the SNC.
The interactional practices of referrals and accounts in medical discourse: Expertise and compliance

This article describes the situated nature of two intertwined dimensions of the context of medical encounters - expertise and compliance - within the interactional practices of referrals and accoun...
Providing developmentally based care for toddlers.

ediatric patients are not just small adults; each child is a unique individual. Even during the “terrible twos,” as many refer to the toddler years when children are actively engaged in learning about their world, however, similarities do exist in perioperative care based on the child’s developmental level. From a developmental perspective, toddlerhood lasts from a child’s first birthday to his or her third birthday. It is a time during which the child throws temper tantrums and demonstrates negativism, passionate exploration, and assertiveness. Parenting a toddler often is demanding and challenging. The prospect of a surgical procedure creates additional stress for the child as well as his or her family members, and this may exacerbate a toddler’s outbursts and hinder parental coping mechanisms. Developmental theories offered by Freud, Piaget, and Erikson can help provide a theoretical foundation for understanding children at each psycho social and cognitive level (Table 1). Nurses who understand these theories may be better equipped to provide holistic, family-centered care. Nurses also must be aware that all humans have the potential to regress developmentally when under stress. The developmental theories presented in this column are intended to help nurses care for patients at this stage of development; if a toddler does regress, developmental interventions that are appropriate for infants should be considered.
Homophones as ambiguous stimuli in research: A comparison of the associative meaning of homophones and nonhomophones

Thirty-six homophones and 36 nonhomophones were presented randomly to 30 Ss in a single response, free association task. The greater dispersion of the response distributions to homophones than to nonhomophone stimuli as well as the longer response latencies to homophones suggested that the associative meaning of homophones is more ambiguous than other elements of the vocabulary and, consequently, that homophone units may be fruitfully employed in research necessitating the use of such ambiguous stimuli. Several such potential uses were discussed along with possible research aimed towards clarifying the phenomenon of homophones per se, apart from their use as research tools.
Oscillations in the reproductive condition of Diaptomus leptopus (Copepoda: Calanoida) and their relation to rates of egg-clutch production.

Isolated female D. leptopus oscillate between gravid and nongravid reproductive conditions. When gravid, the oviducts are visible as a pair of dark bands lateral to the digestive tract. Periodically the females revert to a nongravid condition by releasing all the unfertilized oocytes into the environment. The oviducts then remain transparent until they refill with ripe gametes. The characteristics of this gametogenic cycle were defined at 18° C using females cultured under controlled conditions. The average period of the cycle was 4.4 days, with a gravid phase (dark oviducts) of 3.4 days and a nongravid phase (clear oviducts) of 0.9 days. Observations made in situ confirmed the oscillatory nature of the changes in reproductive status. The duration of the nongravid phase was shown to represent the minimal time interval between successive clutches of fertilized eggs. Estimates of maximal rates of clutch production based on this measure were more than three times higher than those based on the duration of embryonic development. Since unfertilized oocytes disintegrate upon extrusion, a considerable amount of reproductive material may be wasted regularly. A turnover rate of 5.6% body weight (dry) day-1 was calculated for isolated females at 18° C. A model used to estimate the frequency of mating interactions indicated that the probability of oocyte extrusion in lakes may be high and the impact on nutrient pools could be substantial. Up to 0.12 μg phosphorus mg-1 h-1 may be released in the form of unfertilized oocytes.
Small Entrants and Large Incumbents: A Framework of Micro Entry

Translating a diverse body of research, including industrial organization economics, strategy, and entrepreneurship, we present a framework of micro entry—specifically, how de novo entrants penetrate markets dominated by large incumbents without intensifying rivalry. Entrant–incumbent relations has received substantial attention in these three literatures, but with a few exceptions, prior research has focused mainly on hostile entry and on large or comparable players. We explain, however, that acute size differences create distinct entrant–incumbent dynamics. Normatively, we show how, when, and where micro entrants are most likely to penetrate markets dominated by large incumbents. Conceptually, we expand resource partitioning and mutual forbearance theories by relaxing their assumptions and then remeshing their logic, thus offering nuanced insights on entrant–incumbent relations when size differences are very large. Contrary to the creative-destructive hypothesis, we evince that market penetration is mor...
Water Use Conflict Near Madison, Nebraska

: Nebraska statutes give first preference for use of ground water to domestic purposes, second to agriculture, and third to manufacturing or industrial purposes. Rapid growth in the number of irrigation wells has caused an increasing number of water use conflicts. One such conflict arose from the installation and use of an irrigation well near Madison in Madison County, Nebraska. Pumping from the irrigation well coincided with head declines in nearby domestic wells screened in the same sand and gravel, but appeared unrelated to water level changes in wells screened in a higher saturated sand. A drawdown-recovery test was performed to determine the degree of hydraulic connection between the wells involved. Operation of the irrigation well was determined to be the cause of the head decline in nearby domestic wells screened in the same sand and gravel. Partly as a result of this conflict, legislation recently introduced into the state legislature would require that wells of higher preference be “reasonably” constructed if wells of lower preference are to be held liable for head loss.
Spatial variability in nutrient concentration and biofilm nutrient limitation in an urban watershed

Nutrient enrichment threatens river ecosystem health in urban watersheds, but the influence of urbanization on spatial variation in nutrient concentrations and nutrient limitation of biofilm activity are infrequently measured simultaneously. In summer 2009, we used synoptic sampling to measure spatial patterns of nitrate (NO3 −), ammonium (NH4 +), and soluble reactive phosphorus (SRP) concentration, flux, and instantaneous yield throughout the Bronx River watershed within New York City and adjacent suburbs. We also quantified biofilm response to addition of NO3 −, phosphate (PO4 3−), and NO3 − + PO4 3− on organic and inorganic surfaces in the river mainstem and tributaries. Longitudinal variation in NO3 − was low and related to impervious surface cover across sub-watersheds, but spatial variation in NH4 + and SRP was higher and unrelated to sub-watershed land-use. Biofilm respiration on organic surfaces was frequently limited by PO4 3− or NO3 − + PO4 3−, while primary production on organic and inorganic surfaces was nutrient-limited at just one site. Infrequent NO3 − limitation and low spatial variability of NO3 − throughout the watershed suggested saturation of biological N demand. For P, both higher biological demand and point-sources contributed to greater spatial variability. Finally, a comparison of our data to synoptic studies of forested, temperate watersheds showed lower spatial variation of N and P in urban watersheds. Reduced spatial variation in nutrients as a result of biological saturation may represent an overlooked effect of urbanization on watershed ecology, and may influence urban stream biota and downstream environments.
From the "Good Kids" to the "Worst": Representations of English Language Learners across Educational Settings

Based on year-long ethnographic case studies following U.S. immigrants in their last year of secondary school and first year in a 2-year community college, this article contrasts prevalent institutional images of what it means to be an English language learner in these two educational settings. The article draws on the notion of representation, or archetypal images of learner identity, arguing that representation offers a means of understanding how seemingly self-evident and unchanging identities emerge in a particular social context out of ever-evolving processes of identity (re)creation. The article compares representations of ESL student identity in the two educational institutions and illustrates the manifestation of these representations in class curricula and spoken and written interactions. Prevalent institutional images of ESL student identities were appropriated and recreated by students and educators in one context and resisted by students in another. Contending that representation is an inevitable part of human meaning making and identity formation, the article suggests that images of students and of their backgrounds, experiences, and needs not only inform curriculum but also have significant consequences for students' identities and attitudes toward classroom learning.
A D-C transformer

The company with which the authors are connected undertook the design and construction of a device using a mechanical commutator which would transform direct current from one voltage to another. The two major commutator problems are current collection and commutation. It is well known that it is difficult to solve these problems especially if certain limits are exceeded. In the case of current collections, the speed of moving contacts cannot be indefinitely increased. In the case of commutation the chief limitation is in the voltage per bar. Accepting this requirement of design, it is necessary to devise circuits which will give very good commutation of current and voltage under all. conditions of service. Such circuits may be arranged to rectify or invert alternating or direct current or to transform direct current from one voltage to another. If rectification or inversion is attempted, two great difficulties are encountered. First, that of obtaining perfect synchronization of the commutator with the alternating potential and, second, the balancing of the current and voltages of the ac system against those of the dc system. These difficulties are absent in the case of transformation of direct current, using two commutators carried on one shaft and connected respectively to the primary and secondary of a suitable transformer. Synchronization is perfect and inherent and if the number of commutator bars per circuit is the same on the primary and secondary sides of the apparatus, a true balance of current and voltage is possible. The work described here was based on this type of apparatus.
Massive Honey Bee Envenomation-Induced Rhabdomyolysis in an Adolescent

Massive envenomations by honey bees are capable of causing multiorgan dysfunction as a result of the direct toxic effects of the large venom load received. Although all varieties of honey bee have the potential for these attacks, the Africanized honey bee (Apis mellifera scutellata) is the most commonly implicated subspecies. In the United States, the Africanized strain is found primarily in the southwestern states and is known for its highly defensive behavior if disturbed. Mechanisms behind the multiorgan dysfunction produced by these mass envenomations are not clearly understood. We present a case of a 13-year-old male who was stung by ∼700 honey bees and developed progressive upper-body swelling and systemic manifestations of mass envenomation including rhabdomyolysis, renal insufficiency, and a transient transaminase elevation.
HABITAT MATTERS FOR INORGANIC CARBON ACQUISITION IN 38 SPECIES OF RED MACROALGAE (RHODOPHYTA) FROM PUGET SOUND, WASHINGTON, USA1

Measurements of pH drift were used to assess the ability of 38 red algal seaweeds to use bicarbonate and to deplete the dissolved inorganic carbon pool (DIC) from seawater medium. Subtidal algae were typically restricted to the use of DIC in the form of dissolved CO 2 , reducing the initial DIC by only 9%. Intertidal species used both dissolved CO 2 and bicarbonate and reduced initial DIC by as much as 70%. DIC reductions and pH compensation points for the intertidal species tested were strongly correlated with their vertical zonation on the rocky shoreline (analysis of variance). DIC acquisition efficiency increased with tidal height, but species from the upper edge of the intertidal demonstrated a reversal of this trend. This general pattern associated with tidal height was observed not only among intertidal red algae in general, but also among four species of the genus Porphyra (P. terra V. Krishnamurthy, P. papenfussii Krishnamurthy, P. perforata J. Agardh, P. fucicola Krishnamurthy) and among four populations of the broadly distributed species Mastocarpus papillatus (C. Agardh). The Mastocarpus observations suggest either that individuals of this species may be able to express alternate strategies for carbon acquisition or that intertidal height may select for survivorship of genotypes with different carbon acquisition strategies. Taken together, these data suggest that the carbon acquisition strategy of intertidal red algae may be an important physiological set of adaptations that is under active evolutionary selection. These physiological differences were not related to phylogeny, tested as membership in red algal families and orders.
Free vibration of unsymmetrically laminated beams having uncertain ply orientations

Three models were developed to predict randomness in the free vibration response of unsymmetrically laminated beams: exact Monte Carlo simulation, sensitivity-based Monte Carlo simulation, and probabilistic finite element analysis (FEA). It is assumed that randomness in the response is only caused by uncertainties in the ply orientations. The ply orientations may become random or uncertain during the manufacturing process. A new 16-degree-of-freedom beam element, based on the first-order shear deformation beam theory, is adapted for use in studying the probabilistic nature of the natural frequencies. With the use of variational principles, the element stiffness matrix and mass matrix are obtained through analytical integration. With the use of a random sequence, a large data set following normal distribution is generated, containing possible random ply orientations. The sensitivity derivatives are numerically calculated through an exact analytical formulation. The eigenvalues are expressed in terms of deterministic and probabilistic quantities, which allows the determination of how sensitive they are to variations in ply angles. The predicted mean value and coefficient of variation of the natural frequencies for sensitivity-based Monte Carlo simulation and probabilistic FEA are in good agreement with the exact Monte Carlo simulation. Results show that variations of ±5 deg in ply angles have little effect on the lower mode natural frequencies of unsymmetrically and symmetrically laminated beams.
Smooth Dependence of Thermodynamic Limits¶of SRB-Measures

The thermodynamic limits of SRB-measures for uniformly hyperbolic sets are smoothly dependent on the map in an appropriate functional space.
PREDICTION OF PROTEIN SIDE-CHAIN ROTAMERS FROM A BACKBONE-DEPENDENT ROTAMER LIBRARY : A NEW HOMOLOGY MODELING TOOL

Modeling by homology is the most accurate computational method for translating an amino acid sequence into a protein structure. Homology modeling can be divided into two sub-problems, placing the polypeptide backbone and adding side-chains. We present a method for rapidly predicting the conformations of protein side-chains, starting from main-chain coordinates alone. The method involves using fewer than ten rotamers per residue from a backbone-dependent rotamer library and a search to remove steric conflicts. The method is initially tested on 299 high resolution crystal structures by rebuilding side-chains onto the experimentally determined backbone structures. A total of 77% of χ1 and 66% of χ1+2 dihedral angles are predicted within 40° of their crystal structure values. We then tested the method on the entire database of known structures in the Protein Data Bank. The predictive accuracy of the algorithm was strongly correlated with the resolution of the structures. In an effort to simulate a realistic homology modeling problem, 9424 homology models were created using three different modeling strategies. For prediction purposes, pairs of structures were identified which shared between 30% and 90% sequence identity. One strategy results in 82% of χ1 and 72% χ1+2 dihedral angles predicted within 40 degrees of the target crystal structure values, suggesting that movements of the backbone associated with this degree of sequence identity are not large enough to disrupt the predictive ability of our method for non-native backbones. These results compared favorably with existing methods over a comprehensive data set.
Production planning with simulation techniques

Conley (1985) presented a multi-stage simulation algorithm for non-linear systems of equations that could be enhanced by the use of more sophisticated combination transformations in conjunction with his basic simulation sampling scheme. This allows the solution of larger non-linear systems and makes practical the modelling of processes with more variables and constraints. A production scheduling problem with 25 variables and constraints is presented in this paper.
Contact Comfort: A Reconsideration of the Original Work:

Contrary to general belief, published reports of the original infant/surrogate work contain few data to support the idea of a need for contact comfort, and the data which they do contain are incomp...
Oxidation of Polyisoprene Popcorn Polymer. VI. Quantitative Determination of Some of the Volatile Reaction Products

Abstract The primary products produced during the early stages of polyisoprene popcorn polymer autoxidation appear to be water, 2, 5-hexanedione, acetaldehyde, and two unknown compounds. Quantitative data are presented for the production of 2, 5-hexanedione and acetic acid. The scission mechanism undoubtedly involves the formation of acetonyl radicals which recombine to form 2, 5-hexanedione. A scission yield of one mole of scissions per 53 moles of oxygen was calculated for the room-temperature oxidation.
In Vivo 13C NMR Measurements of Hepatocellular Tricarboxylic Acid Cycle Flux

A combined isotopic steady state and in vivo isotopic non-steady state analysis was used to calculate tricarboxylic acid cycle flux in livers of anesthetized rats infused with ethanol. In vivo 13C NMR spectroscopy was used to non-invasively observe label turnover of [4-13C]glutamate, [4-13C]glutamine, and [2-13C]glutamate/glutamine in liver following a bolus intravenous infusion of [2-13C]ethanol. The isotopic steady state analysis of [2-13C], [3-13C], and [4-13C]glutamate isotopomers (Malloy, C. R., Sherry, A. D., and Jeffrey, F. M. H. (1988) J. Biol. Chem. 263, 6964-6971) in liver extracts was used to indirectly calculate the anaplerotic flux (0.90 +/- 0.07 x citrate synthase flux) and [2-13C]acetyl-CoA fractional enrichment (51.4 +/- 3.4%). The [4-13C]glutamate, [4-13C]glutamine, and [2-13C]glutamate fractional enrichments determined in liver extracts were 23.0 +/- 1.1, 17.2 +/- 1.5, and 7.7 +/- 0.5%, respectively. These data in addition to blood [2-13C]acetate and [4-13C]glutamine enrichment time course data were used in conjunction with a metabolic steady state mathematical analysis designed to account for liver glutamate and glutamine label dilution as a consequence of glutamine exchange with blood to calculate the tricarboxylic acid (tca) cycle flux (Vtca = 0.33 +/- 0.09 micromol/g wet weight/min) in liver. In summary, It is possible to detect 13C labeling of glutamate and glutamine in liver via non-invasive 13C NMR. Additionally, the in vivo 13C labeling kinetics of glutamate and glutamine in liver and glutamine in blood may be used to calculate the liver tricarboxylic acid cycle flux.
Surface Relaxation Times of Conduction-Electron Spins in Superconductors and Normal Metals

Electron spin relaxation times in surface collisions were deduced from measurements on superconductors of the NMR Knight shift, critical magnetic fields, and tunneling conductance as well as from measurements on normal metals by conduction-electron spin resonance. The relaxation times ${\ensuremath{\tau}}_{\mathrm{so}}$ as determined by the various methods are consistent and depend on the atomic number of the metal in a manner similar to that proposed by Abrikosov and Gor'kov.
BrainExplorer: an innovative tool for teaching neuroscience

Neuroscience has recently brought many insights into the inner workings of the human brain. The way neuroscience is taught, however, has lagged behind and still relies on direct instruction or textbooks. We argue that the spatial nature of the brain makes it an ideal candidate for hands-on activities coupled with a tangible interface. In this paper we introduce BrainExplorer, a learning environment for teaching neuroscience. BrainExplorer allows users to explore neural pathways on a custom tabletop platform. We conducted an evaluation with 28 participants comparing students who learned neuroscience content through using BrainExplorer with students who learned by reading a textbook chapter. We found that our system promotes learning along 3 dimensions: memorizing scientific terminology, understanding a dynamic system, and transferring knowledge to a new situation.
Large Cost Reductions Made Possible by Reevaluation of Beam Transport Parameters

A detailed study of beam transport hardware for external beams has recently been completed. This study was made from the viewpoint of reducing capital and operating costs of beam components, which could result in a greater number of high quality beams for a given amount of money.
TICLE: using multimedia multimodal guidance to enhance learning

Tangible Interfaces for Collaborative Learning Environments (TICLE) explores new ways that multimedia can enhance education without becoming the focus of the educational experience. A TICLE system "watches" as children work together on puzzles and other educational tasks in a physical environment. The system then responds as a "guide on the side", providing the sort of encouragement and prodding that a teacher would. This builds on children's innate love of puzzles, their collaborative tendencies, and their inclination to learn by doing. Although such a system cannot replace a qualified teacher, it can help teachers to motivate and reach more students simultaneously.This paper outlines the strategies used to create a TICLE system, and describes one implementation: a multimedia multimodal system that responds to children playing with a Tangram puzzle. This system has been installed in the Goudreau Museum of Mathematics in Art and Science, located on Long Island in New York.