bluuebunny/crossref_metadata_2025 huggingface dataset:
Transconductance Enhancement by Utilizing Pattern Dependent Oxidation in Silicon Nanowire Field-Effect Transistors
Authors: Seike Aya , Tange Tomoyuki , Sano Itsutaku , Sugiura Yuuki , Tsuchida Ikushin , Ohta Hiromichi , Watanabe Takanobu , Kosemura Daisuke , Ogura Atsushi , Ohdomari Iwao
Published: May 2008

Transconductance (gm) enhancement in n-type and p-type nanowire field-effect-transistors (nwFETs) is demonstrated by introducing controlled tensile strain into channel regions by pattern dependant oxidation (PADOX). Values of gm are enhanced relative to control devices by a factor of 1.5 in p-nwFETs and 3.0 in n-nwFETs. Strain distributions calculated by a three-dimensional molecular dynamics simulation reveal predominantly horizontal tensile stress in the nwFET channels. The Raman lines in the strain controlled devices display an increase in the full width half maximum, and a shift to lower wavenumber confirming that gm enhancement is due to tensile stress introduced by the PADOX approach.
Silicides for 22nm and Beyond
Authors: Besser Paul R. , Lavoie Christian , Murray Conal , D'Emic Christopher P. , Ohuchi Kazuya
Published: May 2008

Silicide engineering for high-performance CMOS logic devices is challenged by aggressive scaling of critical dimensions, new high-performance elements, and requirements of morphological stability. While NiSi can satisfy many of the integration challenges, incorporating Pt forms a more robust [NixPt(1-x)]Si and improves morphological stability. In light of the challenges created by performance enablers, we review our latest results indicating whether a replacement for NiPt(1-x)Si is needed and highlight our investigations into alternative silicide materials such as Er, Yb, and Ir. We also discuss the architecture and performance needs beyond 32nm technology.
NI (PT) SI Thermal Stability Improvement by Carbon Implantation
Authors: Mertens Sofie , Hoffmann Thomas Y. , Vrancken Christa , Jakschik Stefan , Richard Olivier , Verleysen Eveline , Bender Hugo , Zhao Chao , Vandervorst Wilfried , Absil Philippe , Lauwers Anne
Published: May 2008

The thermal stability of Ni(Pt)-silicides by carbon implantation was evaluated. The Ni(Pt)-silicide morphology and phase formation were studied by means of sheet resistance (Rs) measurements, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) inspection, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis. The substrate crystallinity, carbon implantation dose and energy and the anneal conditions determine the stability of the silicide. Platinum and carbon increase the phase stability of Ni-silicide at high temperatures by increasing the disilicide nucleation temperature. The dominant degradation mechanism is morphological degradation for the NiPtSi:C films whereas transition to the NiSi2 phase is the dominant degradation mechanism for NiSi:C films. As compared to carbon incorporation by epitaxial growth of Si:C, the carbon implant has the advantage of being a simple technique that can also be applied to pMOS devices.
Effects of B or Al Interface Layers on Thermal Stability of Ni Silicide on Si
Authors: Tsutsui Kazuo , Shiozawa Takashi , Nagahiro Koji , Ohishi Yoshihisa , Kakushima Kuniyuki , Ahmet Parhat , Urushihara Nobuaki , Suzuki Mineharu , Iwai Hiroshi
Published: May 2008

A new method is proposed to address the degradation of thermal stability in Ni silicide on heavily doped N-type Si substrates. Layered deposition of Al or B at the Ni/Si interface prior to silicidation was found to improve the thermal stability of Ni silicide, as evaluated by the sheet resistance vs. silicidation temperature properties. The improvement is attributed to suppression of the agglomeration of silicide layers. An Al layer was effective only when it was located at the Ni/Si interface prior to the silicidation process. The use of a B layer was preferable to that of Al when considering lower junction leakage.
Growth and Characterization of MBE-GaN on Si (111) using AlN/α-Si3N4 Buffer Structure
Authors: Chang Jet Rung , Yang Tsung Hsi , Chen Yi Cheng , Ku Jui Tai , Chang Chun Yen
Published: May 2008

In this study, a novel AlN/α-Si3N4 buffer structure is introduced for the growth of thick crack-free GaN on Si(111). The 5:4 coincident lattice in AlN/α-Si3N4/Si(111) structure is related to the reduction of the tensile stress in the AlN and GaN epilayers. Effective reducing the lattice mismatch and stress in GaN/AlN/α-Si3N4/Si structure can alleviate the crack in thick GaN layer. As a result, the crack-free surface of a 2 μm GaN epilayer on Si(111) was demonstrated by using AlN/α-Si3N4 buffer structure. The full widths at half-maximum (FWHM) values of the X-ray rocking curve and neutral-donor-bound exciton (DoX) are 1012 arcsec and 30 meV, respectively.
A Dialect Turned Inside Out
Authors: Hazen Kirk , Hamilton Sarah
Published: May 2008

Migration to economically more prosperous areas has been an attractive choice for many Appalachians. This paper traces the effects of migration on language variation within one Appalachian family. Through qualitative and quantitative analysis of phonological, morphological, and lexical variables, we draw distinctions between family members who remained in West Virginia and those who migrated to Ohio and Michigan. The data come from interviews with nine members of one southern West Virginia family. Aside from migration status, education is the most influential factor in language variation patterns for migrant and non-migrant speakers. Our findings indicate that Appalachian migrants negotiate their sociolinguistic identities by drawing on the norms both of their family members and of their adopted homes. This phenomenon is not isolated to one family; economic conditions have fostered the introduction of external sociolinguistic norms into Appalachian communities for at least seventy years.
A Prospective Evaluation of Propylene Glycol Clearance and Accumulation During Continuous-Infusion Lorazepam in Critically Ill Patients
Authors: Nelsen Jamie L. , Haas Curtis E. , Habtemariam Bahru , Kaufman David C. , Partridge Amy , Welle Stephen , Forrest Alan
Published: May 2008

Propylene glycol is a commonly used diluent in several pharmaceutical preparations, including the sedative lorazepam. Fifty critically ill patients receiving continuous-infusion lorazepam for a minimum of 36 hours were prospectively evaluated to determine the extent of propylene glycol accumulation over time, characterize propylene glycol clearance in the presence of critical illness, and develop a pharmacokinetic model that would predict clearance based on patient-specific clinical, laboratory, and demographic factors. In this cohort, the median lorazepam infusion rate was 2.1 mg/h (0.5-18). Propylene glycol concentration correlated poorly with osmolality, osmol gap, and lactate. In all, 8 patients (16%) had significant propylene glycol accumulation (>25mg/dL). When propylene glycol concentrations were >25 mg/dL, the median lorazepam infusion rate before sample collection was higher, 6.4 (1.9-11.3) versus 2.0 (0.5-7.4) mg/h ( P =.0003). A linear first-order model with interoccasion variability on clearance adjusted for total body weight and Acute Physiology and Chronic Health Evaluation II score predicted propylene glycol concentration.
Treated Prevalence and Incidence of Dementia Among National Health Insurance Enrollees in Taiwan, 1996-2003
Authors: Chien I-Chia , Lin Yu-Chung , Chou Yiing-Jenq , Lin Ching-Heng , Bih Shin-Huey , Lee Cheng-Hua , Chou Pesus
Published: May 2008

The National Health Insurance database to determine the treated prevalence and incidence of dementia in Taiwan was used in this study. A population-based random sample of 22 118 subjects aged 65 or older was obtained as a dynamic cohort. Those study subjects who had filed at least one service claim from 1996 to 2003 for either outpatient care or inpatient care with a principal diagnosis of dementia were identified. The annual treated prevalence increased from 0.71% to 1.92% from 1996 to 2003. The annual treated incidence rates were around 0.76% to 1.04% per year from 1997 to 2003. The annual treated incidence rates for the 5-year age groups, from 65 to 90 years and older, were 0.44%, 0.65%, 0.98%, 1.46%, 1.81%, and 1.80%, respectively. Both the treated prevalence and incidence rates of dementia in National Health Insurance were lower than those of community studies.
Interferometry by deconvolution: Part 2 — Theory for elastic waves and application to drill-bit seismic imaging
Authors: Vasconcelos Ivan , Snieder Roel
Published: May 2008

Deconvolution interferometry successfully recovers the impulse response between two receivers without the need for an independent estimate of the source function. Here we extend the method of interferometry by deconvolution to multicomponent data in elastic media. As in the acoustic case, elastic deconvolution interferometry retrieves only causal scattered waves that propagate between two receivers as if one acts as a pseudosource of the point-force type. Interferometry by deconvolution in elastic media also generates artifacts because of a clamped-point boundary condition imposed by the deconvolution process. In seismic-while-drilling (SWD) practice, the goal is to determine the subsurface impulse response from drill-bit noise records. Most SWD technologies rely on pilot sensors and/or models to predict the drill-bit source function, whose imprint is then removed from the data. Interferometry by deconvolution is of most use to SWD applications in which pilot records are absent or provide unreliable estimates of bit excitation. With a numerical SWD subsalt example, we show that deconvolution interferometry provides an image of the subsurface that cannot be obtained by correlations without an estimate of the source autocorrelation. Finally, we test the use of deconvolution interferometry in processing SWD field data acquired at the San Andreas Fault Observatory at Depth (SAFOD). Because no pilot records were available for these data, deconvolution outperforms correlation in obtaining an interferometric image of the San Andreas fault zone at depth.
A Facile Synthesis of Pyrazolines from Baylis–Hillman Adducts
Authors: Yadav J S , Singh A P , Bhunia D C , Basak A K , Srihari P
Published: May 2008

Baylis–Hillman adducts undergo smooth 1,3-dipolar cycloaddition reaction with ethyl diazoacetate in the presence of 2-iodoxybenzoic acid to produce pyrazolines in high yields under mild reaction conditions.
Directors' Multiple Identities, Identification, and Board Monitoring and Resource Provision
Authors: Hillman Amy J. , Nicholson Gavin , Shropshire Christine
Published: May 2008

Scholars and practitioners are interested in board effectiveness, yet we know relatively little about directors' engagement in the boardroom. We integrate identity theory and social identity theory research with literature on board monitoring and resource provision to model how directors' multiple identities affect their behavior. We propose that directors' strength of identification with multiple identities affects the extent to which they engage in monitoring and resource provision. We discuss implications for corporate governance research and practice.
Advanced Nonlinear Approaches for Predicting the Ingredient Composition in Compound Feedingstuffs by Near-Infrared Reflection Spectroscopy
Authors: Pérez-Marín D. , Garrido-Varo A. , Guerrero J. E. , Fearn T. , Davies A. M. C.
Published: May 2008

For quantitative applications, the most common usage of near-infrared reflection spectroscopy (NIRS) technology, calibration involves establishing a mathematical relationship between spectral data and data provided by the reference. This model may be fairly complex, since the near-infrared spectrum is highly variable and contains physical/chemical information for the sample that may be redundant, and multivariate calibration is usually required. When the relationship to be modeled is nonlinear, classical regression methods are inadequate, and more complex strategies and algorithms must be sought in order to model this nonlinearity. The development of NIRS calibrations to predict the ingredient composition, i.e., the inclusion percentage of each ingredient, in compound feeds is a complex task, due to the nature of the parameters to be predicted and to the heterogeneous nature of the matrices/formulas in which each ingredient participates. The present paper evaluates the use of least squares support vector machines (LSSVM) and two local calibration methods, CARNAC and locally biased regression, for developing NIRS models to predict two of the most representative ingredients in compound feed formulations, wheat and sunflower meal, using a large spectral library of 7523 commercial compound feed samples. For both ingredients, the best results were obtained using CARNAC, with standard errors of prediction (SEP) of 1.7% and 0.60% for wheat and sunflower meal, respectively, and even better results when the algorithm was allowed to refuse to predict 10% of the unknowns. Meanwhile, LSSVM performed less well on wheat (SEP 2.6%) but comparably on sunflower meal (SEP 0.60%), giving results very similar to those reported previously for artificial neural networks. Locally biased regression was the least successful of the three methods, with SEPs of 3.3% for wheat and 0.72% for sunflower meal. All the nonlinear methods improved on the standard approach using partial least squares (PLS), which gave SEPs of 5.3% for wheat and 0.81% for sunflower meal.
Effects of Mild Heating and Acidification on the Molecular Structure of Milk Components as Investigated by Synchronous Front-Face Fluorescence Spectroscopy Coupled with Parallel Factor Analysis
Authors: Boubellouta Tahar , Dufour Éric
Published: May 2008

This paper reports the potential of synchronous front-face fluorescence spectroscopy in the characterization at the molecular level of milk changes during mild heating from 4 to 50 °C and acidification in the pH range of 6.8 to 5.1. Synchronous fluorescence spectra were collected in the 250–550 nm excitation wavelength range using offsets of 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, and 240 nm between excitation and emission monochromators. The potential of parallel factor (PARAFAC) analysis in the decomposition of the whole synchronous fluorescence data set into the contribution of each of the fluorescent compounds present in milk has been investigated for heating and acidification data sets. Models were fitted from 1 to 7 components. Considering the core consistency values, PARAFAC models with three components have been considered. The first three components explained 94.43% and 94.13% of the total variance for heating and acidification data sets, respectively. The loading profiles of the first and second components derived from PARAFAC analysis performed on heating and acidification data sets corresponded quite well with the characteristics of tryptophan and vitamin A fluorescence spectra, respectively. The third component corresponded to the riboflavin fluorescence spectrum. Considering the heating experiment, the profile of the concentration mode for the second component showed large variations according to the temperature, which were assigned to the melting of triglycerides between 4 and 50 °C. For the acidification experiment, drastic changes in the concentration modes of the three components were observed for pH below 5.6, in agreement with structural changes in casein micelles.
Book Reviews: Introduction to the Theory of Coherence and Polarization of Light
Authors: Haes Amanda J.
Published: May 2008

Please forward book reviews to the Book Review Editor, Alexander Scheeline, Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801.
Chiral Recognition of Amino Acids by Use of a Fluorescent Resorcinarene
Authors: Richard Gerald I. , Marwani Hadi M. , Jiang Shan , Fakayode Sayo O. , Lowry Mark , Strongin Robert M. , Warner Isiah M.
Published: May 2008

The spectroscopic properties of a chiral boronic acid based resorcinarene macrocycle employed for chiral analysis were investigated. Specifically, the emission and excitation characteristics of tetraarylboronate resorcinarene macrocycle (TBRM) and its quantum yield were evaluated. The chiral selector TBRM was investigated as a chiral reagent for the enantiomeric discrimination of amino acids using steady-state fluorescence spectroscopy. Chiral recognition of amino acids in the presence of the macrocycle was based on diastereomeric complexes. Results demonstrated that TBRM had better chiral discrimination ability for lysine as compared to the other amino acids. Partial least squares regression modeling (PLS-1) of spectral data for macrocycle-lysine guest–host complexes was used to correlate the changes in the fluorescence emission for a set of calibration samples consisting of TBRM in the presence of varying enantiomeric compositions of lysine. In addition, validation studies were performed using an independently prepared set of samples with different enantiomeric compositions of lysine. The results of multivariate regression modeling indicated good prediction ability of lysine, which was confirmed by a root mean square percent relative error (RMS% RE) of 5.8%.
Analysis of Protein-Based Media Commonly Found in Paintings Using Synchronous Fluorescence Spectroscopy Combined with Multivariate Statistical Analysis
Authors: Nevin Austin , Cather Sharon , Burnstock Aviva , Anglos Demetrios
Published: May 2008

The spectrofluorimetric analysis of protein-based binding media, which are commonly found as painting materials, is based on the detection of emissions from amino acids, as well as fluorescent degradation products that develop with aging. Laser-induced fluorescence spectroscopy, fluorescence excitation emission spectroscopy, and time-resolved fluorescence spectroscopy have all been employed in efforts to discriminate between commonly found proteinaceous binding media, including egg white, egg yolk, milk, and casein, as well as collagen-based glues from rabbit skin, ox bone, parchment, and fish. However, synchronous fluorescence spectroscopy (SFS), a rapid means of recording fluorescence properties of samples, has not been reported for the differentiation between binding media. This work focuses on the analysis of a large set of naturally aged films of different protein-based binding media using SFS with a range of different offsets between excitation and emission monochromators between 30–60 nm. An interpretation of synchronous fluorescence spectra of binding media is presented and is followed by an assessment and classification of a database of recorded spectra using multivariate analysis. Importantly, following SFS analysis of films of binding media, principal component analysis is used to differentiate among all the proteinaceous media considered on the basis of clustering of data. This application is thus a novel and nondestructive means for differentiation between protein-based binding media.
The Influence of Residual Stresses on the Fatigue Strength of Cold-Formed Structural Tubes
Authors: Heinilä Sami , Björk Timo , Marquis Gary
Published: May 2008

Rectangular hollow sections (RHS) are widely used in load-carrying structures due to their good load transfer behavior and aesthetic form. During fabrication of a cold-formed rectangular hollow section (CFRHS), the concave inside corner surfaces experience significant compressive plastic strains. The resulting tensile residual stresses in the corner region significantly reduce the fatigue strength in some design applications. Sections cut from CFRHSs with two different wall thicknesses were studied using distortion fatigue loading and using X-ray diffraction residual stress measurements. Residual stresses and fatigue strengths were virtually identical for the two thicknesses even though the corner radius to thickness ratio was different. Residual stresses were found to significantly influence those corners subjected to compression-compression loading. Fatigue strength of these corners was improved by a stress relief heat treatment, but the treatment had no significant effect on corners subjected to tension-tension loading.
A Comparison of Two Crush Test Methods for Honeycombs Under Compression and Shear
Authors: Hong Sung-Tae , Pan Jwo , Tyan Tau , Prasad Priya
Published: May 2008

Two different crush test methods for aluminum honeycombs under compression and shear loads with respect to the out-of-plane direction are presented in this paper. The honeycomb specimen geometry and the test fixtures for the two test methods are first presented. The combined load method used a test frame with two actuators and the inclined load method employed a multiaxial load cell. The experimental results obtained from the two test methods are presented. The experimental results in terms of the normal crush and shear strengths obtained from the combined and inclined load methods are quite consistent. The experimental results also indicate that under inclined loads, neglecting the constraint force can result in significant error, and the error due to the negligence of the constraint force becomes more pronounced as the inclined loading angle and the in-plane orientation angle increase.
A Menu and a Mystery: The Case of the 1834 Delmonico Bill of Fare
Authors: steinberg ellen f. , prost jack h.
Published: May 2008

The one document in the history of American cuisine that is probably cited more frequently than any other is the so-called ““1834 Delmonico menu”” that situates an early Delmonico restaurant at 494 Pearl Street in Manhattan. Allegedly printed in 1834, this bill of fare is often touted as the first restaurant menu printed in America. It has been mentioned in a variety of other contexts, too: in histories of Delmonico's restaurant and of that quintessential ““American”” food, the hamburger, in discussions about the semantics of menu language, and as an illustration of early menu design. The prices it quotes have been used to illustrate historical food costs and inflation, and it has even been co-opted to tout restaurants aspiring to the standards set long ago by the famed restaurateur Lorenzo Delmonico.

Our investigation suggests the so-called ““1834 Delominco menu”” was never issued by the celebrated Delmonico family. Rather, it was a handbill for a ““cheap dining hall”” called ““Small Delmonico's,”” at 494 Pearl Street, in New York City, owned and operated during the late 1880's by an Italian immigrant named Barnabo.
Reading a Plate
Authors: dudek nir
Published: May 2008

The current paper examines the development of the culinary text during the last decade, in both its written and edible forms. It opens by outlining the metamorphosis of the restaurant menu from a mere inventory of dishes into a set of metaphors, thus requiring an active process of interpretation. This is followed by an analysis of the tension in contemporary molecular cuisine, between modern and postmodern tendencies. Although ““molecular chefs”” are often described as postmodern, and adhere to theoretical concepts suggested by postmodern philosophers, the paper claims that their work is actually modern, that is ““new for the sake of new””. By enthusiastically challenging dominant culinary narratives, the chefs actually consolidate these narratives as standard reference points, therefore turning their own alternatives into mere curiosities. The paper concludes by describing the distinctive state of consciousness created by the molecular gastronomy dining experience. Facing conflicting sensory stimuli, the diner is forced to assimilate the chef's flow of associations, in order to endure the experience. This contributes to a diffusion of limits between the two, making the molecular dining experience unique, not only gastronomically but also psychologically.
Innovate Green Office: a new standard for sustainable buildings
Authors: King D.
Published: May 2008

The Innovate Green Office in Leeds, UK was awarded the highest ever Building Research Establishment environmental assessment method (Breeam) score of 87·55. While previous exemplar sustainable buildings have been constructed for owner occupiers, this project is a demonstration of a sustainable commercial office built speculatively by a developer. The £5·5 million, 4350m2 building demonstrates a wide range of novel techniques for reducing resource consumptionand carbon dioxide (CO2) emissions both in construction and use. Featuring passive environmental design, the building eschews bolt-on sustainable technologies in favour of good insulation, thermal mass and daylight to reduce emissions of CO2 to 20%; of a conventional office building. Importantly, savings in energy and water consumption at a time of increasing volatility in energy costs also provide savings in operating cost, making the building commercially attractive.
MULTIPLE FUNCTIONS INCREASE THE IMPORTANCE OF BIODIVERSITY FOR OVERALL ECOSYSTEM FUNCTIONING
Authors: Gamfeldt Lars , Hillebrand Helmut , Jonsson Per R.
Published: May 2008

Biodiversity is proposed to be important for the rate of ecosystem functions. Most biodiversity–ecosystem function studies, however, consider only one response variable at a time, and even when multiple variables are examined they are analyzed separately. This means that a very important aspect of biodiversity is overlooked: the possibility for different species to carry out different functions at any one time. We propose a conceptual model to explore the effects of species loss on overall ecosystem functioning, where overall functioning is defined as the joint effect of many ecosystem functions. We show that, due to multifunctional complementarity among species, overall functioning is more susceptible to species loss than are single functions. Modeled relationships between species richness and overall ecosystem functioning using five empirical data sets on monocultures reflected the range of effects of species loss on multiple functions predicted by the model. Furthermore, an exploration of the correlations across functions and the degree of redundancy within functions revealed that multifunctional redundancy was generally lower than single‐function redundancy in these empirical data sets. We suggest that by shifting the focus to the variety of functions maintained by a diversity of species, the full importance of biodiversity for the functioning of ecosystems can be uncovered. Our results are thus important for conservation and management of biota and ecosystem services.
RESOURCE‐RATIO THEORY APPLIED TO LARGE HERBIVORES
Authors: Murray Martyn G. , Baird David R.
Published: May 2008

The theoretical description of exploitation competition, known as resource competition theory (RCT) or resource‐ratio theory, has been tested in terrestrial plant communities and microorganisms in laboratory cultures. Applications in animal ecology have been rare, although the theory itself is generic. A major difficulty is that the description of resources in RCT is fundamentally different from that used in classical studies of animal competition. In presenting the first fully specified RCT models for terrestrial animals, we distinguish between positive attributes (mineral elements) and negative attributes (plant defenses) as indicators of quality in animal resources. Using the latter we apply RCT to ungulate communities that exploit just two resources: the cell wall and cell contents of plant material. We show how coexistence in the same habitats depends on the strategy of resource exploitation. Ungulate species that differ in body size adopt a “demand‐minimizing” strategy that permits them to coexist on ratios of the two resources by acquiring less of the resource that most limits their competitor. Ungulates that differ in mouth width adopt an “extraction‐maximizing” strategy that leads to competitive exclusion because they acquire more of the resource that most limits their competitor. We conclude that differential resource utilization permits grazing herbivores of different body size to coexist on the same grassland habitats, but that the full diversity of grazing communities depends on spatial heterogeneity in plant defenses at the landscape level.
BIOGENIC DISTURBANCE DETERMINES INVASION SUCCESS IN A SUBTIDAL SOFT‐SEDIMENT SYSTEM
Authors: Lohrer Andrew M. , Chiaroni Luca D. , Hewitt Judi E. , Thrush Simon F.
Published: May 2008

Theoretically, disturbance and diversity can influence the success of invasive colonists if (1) resource limitation is a prime determinant of invasion success and (2) disturbance and diversity affect the availability of required resources. However, resource limitation is not of overriding importance in all systems, as exemplified by marine soft sediments, one of Earth's most widespread habitat types. Here, we tested the disturbance–invasion hypothesis in a marine soft‐sediment system by altering rates of biogenic disturbance and tracking the natural colonization of plots by invasive species. Levels of sediment disturbance were controlled by manipulating densities of burrowing spatangoid urchins, the dominant biogenic sediment mixers in the system. Colonization success by two invasive species (a gobiid fish and a semelid bivalve) was greatest in plots with sediment disturbance rates <500 cm3·m−2·d−1, at the low end of the experimental disturbance gradient (0 to >9000 cm3·m−2·d−1). Invasive colonization declined with increasing levels of sediment disturbance, counter to the disturbance–invasion hypothesis. Increased sediment disturbance by the urchins also reduced the richness and diversity of native macrofauna (particularly small, sedentary, surface feeders), though there was no evidence of increased availability of resources with increased disturbance that would have facilitated invasive colonization: sediment food resources (chlorophyll a and organic matter content) did not increase, and space and access to overlying water were not limited (low invertebrate abundance). Thus, our study revealed the importance of biogenic disturbance in promoting invasion resistance in a marine soft‐sediment community, providing further evidence of the valuable role of bioturbation in soft‐sediment systems (bioturbation also affects carbon processing, nutrient recycling, oxygen dynamics, benthic community structure, and so on.). Bioturbation rates are influenced by the presence and abundance of large burrowing species (like spatangoid urchins). Therefore, mass mortalities of large bioturbators could inflate invasion risk and alter other aspects of ecosystem performance in marine soft‐sediment habitats.
ECOLOGICAL AND PHYSIOLOGICAL CONTROLS OF SPECIES COMPOSITION IN GREEN MACROALGAL BLOOMS
Authors: Nelson Timothy A. , Haberlin Karalon , Nelson Amorah V. , Ribarich Heather , Hotchkiss Ruth , Alstyne Kathryn L. Van , Buckingham Lee , Simunds Dejah J. , Fredrickson Kerri
Published: May 2008

Green macroalgal blooms have substantially altered marine community structure and function, specifically by smothering seagrasses and other primary producers that are critical to commercial fisheries and by creating anoxic conditions in enclosed embayments. Bottom‐up factors are viewed as the primary drivers of these blooms, but increasing attention has been paid to biotic controls of species composition. In Washington State, USA, blooms are often dominated by Ulva spp. intertidally and Ulvaria obscura subtidally. Factors that could cause this spatial difference were examined, including competition, grazer preferences, salinity, photoacclimation, nutrient requirements, and responses to nutrient enrichment. Ulva specimens grew faster than Ulvaria in intertidal chambers but not significantly faster in subtidal chambers. Ulva was better able to acclimate to a high‐light environment and was more tolerant of low salinity than Ulvaria. Ulvaria had higher tissue N content, chlorophyll, chlorophyll b : chlorophyll a, and protein content than Ulva. These differences suggest that nitrogen availability could affect species composition. A suite of five grazers preferred Ulva to Ulvaria in choice experiments. Thus, bottom‐up factors allow Ulva to dominate the intertidal zone while resistance to grazers appears to allow Ulvaria to dominate the subtidal zone. While ulvoid algae are in the same functional‐form group, they are not functionally redundant.
WETLANDS AS AN ALTERNATIVE STABLE STATE IN DESERT STREAMS
Authors: Heffernan James B.
Published: May 2008

Historically, desert drainages of the American southwest supported productive riverine wetlands (ciénegas). Region‐wide erosion of ciénegas during the late 19th and early 20th century dramatically reduced the abundance of these ecosystems, but recent reestablishment of wetlands in Sycamore Creek, Arizona, USA, provides an opportunity to evaluate the mechanisms underlying wetland development. A simple model demonstrates that density‐dependent stabilization of channel substrate by vegetation results in the existence of alternative stable states in desert streams. A two‐year (October 2004–September 2006) field survey of herbaceous cover and biomass at 26 sites located along Sycamore Creek is used to test the underlying assumption of this model that vegetation cover loss during floods is density dependent, as well as the prediction that the distribution of vegetation abundance should shift toward bimodality in response to floods. Observations of nonlinear, negative relationships between herbaceous biomass prior to flood events and the proportion of persistent vegetation cover were consistent with the alternative stable state model. In further support of the alternative‐state hypothesis, vegetation cover diverged from an approximately normal distribution toward a distinctly bimodal distribution during the monsoon flood season of 2006. These results represent the first empirically supported example of alternative‐state behavior in stream ecosystems. Identification of alternative stable states in desert streams supports recent hypotheses concerning the importance of strong abiotic‐disturbance regimes and biogeomorphic mechanisms in multiple‐state ecosystems.
GROWTH RATES, SEED SIZE, AND PHYSIOLOGY: DO SMALL‐SEEDED SPECIES REALLY GROW FASTER
Authors: Turnbull Lindsay A. , Paul-Victor Cloé , Schmid Bernhard , Purves Drew W.
Published: May 2008

Relative growth rate (RGR) is currently the most commonly used method for measuring and comparing species' intrinsic growth potential. Comparative studies have, for example, revealed that small‐seeded species have higher RGR, leading to the common belief that small‐seeded species possess physiological adaptations for rapid growth that would allow them to outgrow large‐seeded species, given sufficient time. We show that, because RGR declines as individual plants grow, it is heavily biased by initial size and does not measure the size‐corrected growth potential that determines the outcome of competition in the long term. We develop a daily growth model that includes a simple mechanistic representation of aboveground and belowground growth and its dependency on plant size and environmental factors. Intrinsic growth potential is encapsulated by the size‐independent growth coefficient, G. We parameterized the model using repeated‐harvest data from 1724 plants of nine species growing in contrasting nutrient and temperature regimes. Using information‐theoretic criteria, we found evidence for interspecific differences in only three of nine model parameters: G, aboveground allocation, and frost damage. With other parameters shared between species, the model accurately reproduced above‐ and belowground biomass trajectories for all nine species in each set of environmental conditions. In contrast to conventional wisdom, the relationship between G and seed size was positive, despite a strong negative correlation between seed size and average RGR, meaning that large‐seeded rather than small‐seeded species have higher size‐corrected growth potential. Further, we found a significant positive correlation between G and frost damage that, according to simulations, causes rank reversals in final biomass under daily temperature changes of ±5°C. We recommend the wider use of this new kind of plant growth analysis as a better way of understanding underlying differences in species' physiology; but we recognize that RGR is still a useful metric if considering the potential rate of population increase in empty habitats.
A CHEMICAL TRAIT CREATES A GENETIC TRADE‐OFF BETWEEN INTRA‐ AND INTERSPECIFIC COMPETITIVE ABILITY
Authors: Lankau Richard
Published: May 2008

The importance of non‐resource‐based mechanisms of competition between plant species has been increasingly recognized, but little is known about how genetic variation and evolutionary changes in the underlying competitive traits might affect species coexistence. I found that genetic variation in sinigrin concentration, a putative allelopathic agent in Brassica nigra, affected the fitness of three heterospecific neighbor species but did not affect neighboring B. nigra individuals. Investment in sinigrin led to a negative genetic correlation between intra‐ and interspecific competitive ability, which over many generations could provide a strong stabilizing force maintaining both species and genetic diversity in this system.
ASSOCIATIONS OF VARIABLE COLORATION WITH NICHE BREADTH AND CONSERVATION STATUS AMONG AUSTRALIAN REPTILES
Authors: Forsman Anders , Åberg Viktor
Published: May 2008

We evaluate predictions concerning the evolutionary and ecological consequences of color polymorphisms. Previous endeavors have aimed at identifying conditions that promote the evolution and maintenance within populations of alternative variants. But the polymorphic condition may also influence important population processes. We consider the prediction that populations that consist of alternative “ecomorphs” with coadapted gene complexes will utilize more diverse resources and display higher rates of colonization success, population persistence, and range expansions, while being less vulnerable to range contractions and extinctions, compared with monomorphic populations. We perform pairwise comparative analyses based on information for 323 species of Australian lizards and snakes. We find that species with variable color patterns have larger ranges, utilize a greater diversity of habitat types, and are underrepresented among species currently listed as threatened. These results are consistent with the proposition that the co‐occurrence of multiple color variants may promote the ecological success of populations and species, but there are also alternative interpretations.
Fatal Non-Transplant-Related Epstein-Barr Virus–Associated Atypical Lymphoid Proliferations in Infants and Children: A Clinicopathologic Study
Authors: Salama Mohamed E. , Parham David M. , Perkins Sherrie L. , Bahler David W. , Ellison Dale A.
Published: May 2008

Most Epstein-Barr virus (EBV)–related infections in infants and children are asymptomatic or self-limited mild viral illnesses, but rare cases of a rapidly fatal disorder have been described. Failure of the cellular response to control EBV-related lymphoid proliferation leads to severe disease with multiple complications, including a fatal outcome or development of an EBV-driven, clonal lymphoid neoplasm. In this report we characterize 3 cases of fatal, nontransplant, or immunodeficiency-related EBV infection in very young children with immunophenotypic and molecular evidence of B/natural killer (NK)-T cell clonal expansion. An immunohistochemical staining panel included testing for B-cell antigen (CD20), and T/NK cell antigens including CD2, CD3, CD4, CD8, CD56, CD57, and TIA-1. T-cell and B-cell PCR clonality testing was performed on paraffin tissue specimens to identify clonal populations. The ages of these 3 patients ranged from 22 months to 4 years. Initial clinical presentations included pneumonia, abnormal liver function tests and fever, and lymphadenopathy. The 3 patients died within 17 to 72 days of presentation, and autopsy was performed on 1 patient. All cases demonstrated prominent atypical lymphoid or lymphohistiocytic infiltrates, and necrosis was present in 2 of the 3 cases. The atypical lymphocytes were positive for CD3 (cytoplasmic), CD2, CD8, TIA-1, and CD57 and negative for CD4. We molecularly identified B-cell clones in the 2 tested patients, who also showed evidence of hemophagocytosis. Fatal EBV infection is characterized by a morphologic spectrum with atypical lymphoid infiltrates and variable necrosis. Our molecular studies of these patients suggest a clonally-derived expansive process, most likely driven by EBV infection. Our results also suggest that development of clonality is associated with an aggressive clinical course and may be useful in predicting greater risk for fatal outcome. A high index of suspicion, coupled with appropriate serologic and molecular testing, aids in early recognition and diagnosis of these lymphoproliferative processes.
“All That You Can't Leave Behind”
Authors: Brooks Daphne A.
Published: May 2008

This essay explores the critical work of Beyoncé's second solo recording, and places it in conversation with yet another under-theorized yet equally dissonant R&B performance by her “hip-hop soul queen” contemporary Mary J. Blige. In relation to both Beyoncé's and Blige's work, I examine the politics of black women's pop music culture in relation to the Gulf Coast catastrophe and the extreme marginalization of black women in American sociopolitical culture. I suggest that we look closely at the musical performances of Beyoncé as well as Blige, as each artist's work creates a particular kind of black feminist surrogation, that is, an embodied performance that recycles palpable forms of black female sociopolitical grief and loss as well as spirited dissent and dissonance. Their combined efforts mark a new era of protest singing that sonically resists, revises, and reinvents the politics of black female hypervisibility in the American cultural imaginary.
Women, Pop Music, and Pornography
Authors: LeVande Meredith
Published: May 2008

Musician and feminist Meredith LeVande noticed a dramatic shift in the appearance of female pop stars in the late 1990s. This essay shows how the connection between media ownership deregulation and the mega-media companies that profit from adult entertainment have pushed pornographic imagery into the mainstream. Nowhere is this situation more evident than with women in popular music whose images have become increasingly hyper-sexualized. Through various narratives circling women in music, this essay explores how the 1996 Telecommunications Act has made pornographic images omnipresent.
Amphiphilic Helical Peptide Enhances the Uptake of Single-Walled Carbon Nanotubes by Living Cells
Authors: Chin Shook-Fong , Baughman Ray H. , Dalton Alan B. , Dieckmann Gregg R. , Draper Rockford K. , Mikoryak Carole , Musselman Inga H. , Poenitzsch Vasiliki Z. , Xie Hui , Pantano Paul
Published: May 2008

The success of many projected applications of carbon nano-tubes (CNTs) to living cells, such as intracellular sensors and nanovectors, will depend on how many CNTs are taken up by cells. Here we report the enhanced uptake by HeLa cells of single-walled CNTs coated with a designed peptide termed nano-1. Atomic force microscopy showed that the dispersions were composed of individual and small bundles of nano-1 CNTs with 0.7- to 32-nm diameters and 100- to 400-nm lengths. Spectroscopic characterizations revealed that nano-1 disperses CNTs in a non-covalent fashion that preserves CNT optical properties. Elemental analyses indicated that our sample preparation protocol involving sonication and centrifugation effectively eliminated metal impurities associated with CNT manufacturing processes. We further showed that the purified CNT dispersions are taken up by HeLa cells in a time- and temperature-dependent fashion, and that they do not affect the HeLa cell growth rate, evidence that the CNTs inside cells are not toxic under these conditions. Finally, we discovered that ~6-fold more CNTs are taken up by cells in the presence of nano-1 compared with medium containing serum but no peptide. The fact that coating CNTs with a peptide enhances uptake offers a strategy for improving the performance of applications that require CNTs to be inside cells.
Antiarrhythmic Properties of Acetaminophen in the Dog
Authors: Merrill Gary F. , Merrill Jared H. , Golfetti Roseli , Jaques Kathryn M. , Hadzimichalis Norell S. , Baliga Sunanda S. , Rork Tyler H.
Published: May 2008

Mongrel dogs bred for research and weighing 25 ± 3 kg were used to test the hypothesis that acetaminophen has antiar-rhythmic properties. Only ventricular arrhythmias defined by the Lambeth Conventions were investigated. Dogs were exposed either to 60 mins of regional myocardial ischemia followed by 180 mins of reperfusion ( n = 14) or were administered a high dose of ouabain ( n = 14). Both groups of 14 dogs were further divided into vehicle and acetaminophen treatment groups ( n = 7 in each). During selected 10-min intervals, we recorded the numbers of ventricular premature beats, ventricular salvos, ventricular bigeminy, ventricular tachycardia (nonsustained and sustained), and we recorded the heart rate, systemic arterial blood pressure, and left ventricular function. Neither heart rate nor the number of ventricular arrhythmias differed significantly under baseline conditions. Conversely, the combined average number of ventricular ectopic beats during ischemia and reperfusion was significantly less in the presence of acetaminophen (28 ± 4 vs. 6 ± 1; P < 0.05). Similarly, percent ectopy during reperfusion in vehicle- and acetaminophen-treated dogs was 1.4 ± 0.4 and 0.4 ± 0.2, respectively ( P < 0.05). The number of all ventricular ectopic beats except ventricular salvos was also significantly reduced in the presence of acetaminophen. Similar results were obtained with ouabain. Our results reveal that systemic administration of a therapeutic dose of acetaminophen has previously unreported antiarrhythmic effects in the dog.
A Comparison and Critical Analysis of Preclinical Anticancer Vaccination Strategies
Authors: Kochenderfer J. N. , Gress R. E.
Published: May 2008

Anticancer vaccines have been extensively studied in animal models and in clinical trials. While vaccination can lead to tumor protection in numerous murine models, objective tumor regressions after anticancer vaccination in clinical trials have been rare. B16 is a poorly immunogenic murine melanoma that has been extensively used in anticancer vaccination experiments. Because B16 has been widely used, different vaccination strategies can be compared. We reviewed the results obtained when B16 was treated with five common vaccine types: recombinant viral vaccines, DNA vaccines, dendritic cell vaccines, whole-tumor vaccines, and peptide vaccines. We also reviewed the results obtained when B16 was treated with vaccines combined with adoptive transfer of tumor antigen–specific T cells. We found several characteristics of vaccination regimens that were associated with antitumor efficacy. Many vaccines that incorporated xenogeneic antigens exhibited more potent anticancer activity than vaccines that were identical except that they incorporated the syngeneic version of the same antigen. Interleukin-2 enhanced the antitumor efficacy of several vaccines. Finally, several effective regimens generated large numbers of tumor antigen–specific CD8+T cells. Identification of vaccine characteristics that are associated with antitumor efficacy may aid in the development of more effective anticancer vaccination strategies.