bluuebunny/crossref_metadata_2025 huggingface dataset:
Dried polyacrylamide gel absorption: A method for efficient elimination of the interferences from SDS‐solubilized protein samples in mass spectrometry‐based proteome analysis
Authors: Zhou Jian , Li Jianglin , Li Jianjun , Chen Ping , Wang Xianchun , Liang Songping
Published: November 2010

Sample preparation holds an important place in MS‐based proteome analysis. For effective proteolysis and MS analysis, it is essential to eliminate the interferences while extracting the analytes of interest from complex mixtures. To address this, herein we describe a new dried polyacrylamide gel absorption method. In this method, the protein sample prepared using high concentration of SDS was directly and completely absorbed by vacuum‐dried polyacrylamide gel, and then the interfering substances including SDS and some other salts were efficiently removed by in‐gel washing steps while retaining the denatured proteins in the gel, thus offering a clean environment amenable to downstream buffer exchange, proteolytic digestion and digest recovery, etc. In combination with in‐gel digestion and LC‐MS/MS, the newly developed method was applied to the proteome analyses of membrane‐enriched fraction and whole tissue homogenate. It was demonstrated that the method is suitable for the analysis of a complex biological sample and can be widely used for sample cleanup in shotgun proteome analyses.
Mechanical Characterisation at Nanometric Scale of a New Design of SOFCs
Authors: Roa J. J. , Ruiz‐Morales J. C. , Canales‐Vázquez J. , Morales M. , G Capdevila X. , Núñez P. , Segarra M.
Published: November 2010

The mechanical stability is an important parameter to gain knowledge in the potential applications of a novel design of electrolyte‐supported SOFC, based on yttria‐stabilised zirconia (YSZ) and NiO‐YSZ composites, with cross‐linked channels (∼90 μm of diameter). In this experimental work, the mechanical properties (hardness, H and Young's modulus, E) at different applied loads have been studied using the nanoindentation technique and the equivalent indenter method. On the other hand, the different fracture mechanisms have been determined using atomic force microscopy (AFM), observing the plastic behaviour that takes place during the indentation process. H value for YSZ is higher than that for NiO‐YSZ, while E values for YSZ and NiO‐YSZ are 260 ± 15 and 205 ± 20 GPa, respectively. Only YSZ samples present several radial cracks at the corners nucleated by sharp indentation, thus indicating that H values have been underestimated.
Body weight at age 20 years, subsequent weight change and breast cancer risk defined by estrogen and progesterone receptor status—the Japan public health center‐based prospective study
Authors: Suzuki Reiko , Iwasaki Motoki , Inoue Manami , Sasazuki Shizuka , Sawada Norie , Yamaji Taiki , Shimazu Taichi , Tsugane Shoichiro ,   The Japan Public Health Center‐based Prospective Study Group
Published: November 2010

Few prospective studies have investigated the association between BMI at age 20 years (BMI20y) and breast cancer risk with consideration to estrogen/progesterone receptor status (ER/PR). We evaluated the association between BMI20y and ER/PR‐defined breast cancer risk among 41,594 women in the population‐based Japan Public Health Center‐based Prospective Study. Anthropometric factors were assessed using self‐reported questionnaires. Relative risks (RRs) were estimated by Cox proportional hazards regression models. Through to the end of 2006, 452 breast cancer cases were identified. We observed a statistically significant inverse association between BMI20y and breast cancer incidence [multivariable‐adjusted RR for each 5‐unit increment 0.75 (95%CI = 0.61–0.92)], which was not modified by menopausal or recent BMI status. In contrast, recent BMI and subsequent BMI gain were not associated with increased risk among premenopausal women, but were substantially associated with increased risk among postmenopausal women [corresponding RRrecent BMI = 1.31 (95%CI = 1.07–1.59); RRsubsequent BMI gain = 1.32 (95%CI = 1.09–1.60)]. In subanalyses by receptor status (∼50% of cases), the observed inverse association of BMI20y with risk was consistent with the result for ER–PR– [0.49 (95%CI = 0.27–0.88)], while the observed positive associations of BMI gain with postmenopausal breast cancer risk appeared to be confined to ER+PR+ tumors [corresponding RRfor subsequent BMI gain =2.24 (95%CI = 1.50–3.34)]. Low BMI at age 20 years was substantially associated with an increased risk of breast cancer. In contrast, high recent BMI and subsequent BMI gain from age 20 were associated with increased risk of postmenopausal ER+PR+ tumors.
Age as a key factor influencing metastasizing patterns and disease‐specific survival after sentinel lymph node biopsy for cutaneous melanoma
Authors: Kretschmer Lutz , Starz Hans , Thoms Kai‐Martin , Satzger Imke , Völker Bernward , Jung Klaus , Mitteldorf Christina , Bader Claudia , Siedlecki Katharina , Kapp Alexander , Bertsch Hans Peter , Gutzmer Ralf
Published: November 2010

In our study, we investigated the impact of the constitutional factor age on the clinical courses of melanoma patients with sentinel lymph node (SLN) biopsy. Descriptive statistics, Kaplan‐Meier estimates, logistic regression analysis and the Cox proportional hazards model were used to study a population of 2,268 consecutive patients from three German melanoma centers. Younger age was significantly related to less advanced primary tumors. Nevertheless, patients younger than 40 years of age had a twofold risk of being SLN‐positive (p < 0.000001). Of the young patients with primary melanomas with a thickness of 0.76 mm to 1.0 mm, 19.7% were SLN‐positive. Using multivariate analysis, younger age, increasing Breslow thickness, ulceration and male sex were significantly related to a higher probability of SLN‐metastasis. During follow‐up, older patients displayed a significantly increased risk of in‐transit recurrences (p = 0.000002) and lymph node recurrences (p = 0.0004). With respect to melanoma specific overall survival the patient's age was highly significant in the multivariate analysis. The unfavorable effect of being older was significant in the subgroups with positive and negative SLNs. Age remained also significant for the survival after the onset of distant metastases (p = 0.002). In conclusion, the patient's age is a strong and independent predictor of melanoma‐specific survival in patients with localized melanomas, in patients with positive SLNs and after the onset of distant metastases. Younger patients have a better prognosis despite their higher probability of SLN metastasis. Older patients are less frequently SLN‐positive but have a higher risk of loco‐regional recurrence.
Expression profiling of GIST: CD133 is associated with KIT exon 11 mutations, gastric location and poor prognosis
Authors: Arne Gabriella , Kristiansson Erik , Nerman Olle , Kindblom Lars‐Gunnar , Ahlman Håkan , Nilsson Bengt , Nilsson Ola
Published: November 2010

In gastrointestinal stromal tumors (GISTs), KIT exon 11 deletions are associated with poor prognosis. The aim of this study was to determine the gene expression profiles of GISTs carrying KIT exon 11 deletions and to identify genes associated with poor prognosis. Expression profiling was performed on nine tumors with KIT exon 11 deletions and 7 without KIT exon 11 mutations using oligonucleotide microarrays. In addition, gene expression profiles for 35 GISTs were analyzed by meta‐analysis. Expression of CD133 (prominin‐1) protein was examined by tissue microarray (TMA) analysis of 204 GISTs from a population‐based study in western Sweden. Survival analysis was performed on patients subjected to R0 resection (n = 180) using the Cox proportional hazards model. Gene expression profiling, meta‐analysis, and qPCR showed up regulation of CD133 in GISTs carrying KIT exon 11 deletions. Immunohistochemical analysis on TMA confirmed CD133 expression in 28% of all tumors. CD133 positivity was more frequent in gastric GISTs (48%) than in small intestinal GISTs (4%). CD133 positivity was also more frequent in GISTs with KIT exon 11 mutations (41%) than in tumors with mutations in KIT exon 9, platelet‐derived growth factor receptor α (PDGFRA), or wild‐type tumors (0–17%). Univariate survival analysis showed a significant correlation between the presence of CD133 protein and shorter overall survival (hazard ratio = 2.23, p = 0.027). Multivariate analysis showed that CD133 provided additional information on patient survival compared to age, sex, National Institutes of Health (NIH) risk group and mutational status. CD133 is expressed in a subset of predominantly gastric GISTs with KIT exon 11 mutations and poor prognosis.
Inhibitory effect of pisosterol on human glioblastoma cell lines with C‐MYC amplification
Authors: Pereira Edmundo L. R. , Lima Patrícia D. L. , Khayat André S. , Bahia Marcelo O. , Bezerra Franciglauber S. , Andrade‐Neto Manoel , Montenegro Raquel C. , Pessoa Cláudia , Costa‐Lotufo Letícia V. , Moraes Manoel O. , Yoshioka France K. N. , Pinto Giovanny R. , Burbano Rommel R.
Published: November 2010

Despite the remarkable progress in the characterization of the molecular pathogenesis of glioblastoma multiforme (GBM), these tumors remain incurable and, in most cases, refractory to aggressive cytotoxic treatments. We conducted a morphological and cytogenetic study in two GBM cell lines (U343 and AHOL1), before and after treatment with pisosterol (at 0.5, 1.0 and 1.8 µg ml−1), a triterpene isolated from the fungus Pisolithus tinctorius. No significant alteration was observed in the morphology and frequency of chromosomal abnormalities in the cell lines analyzed after treatment with pisosterol. Using fluorescence in situ hybridization analysis with a locus‐specific probe for C‐MYC showed that 72% of U343 and 65% of AHOL1 cells contained more than two alleles of C‐MYC before treatment. After treatment, no effects were detected at lower concentrations of pisosterol (0.5 and 1.0 µg ml−1). However, at 1.8 µg ml−1 of pisosterol, only 33% of U343 cells and 15% of AHOL1 cells presented more than two fluorescent signals, suggesting that pisosterol blocks the cells with gene amplification. Cells that do not show a high degree of C‐MYC gene amplification have a less aggressive and invasive behavior and are easy targets for chemotherapy. Therefore, further studies are needed to examine the use of pisosterol in combination with conventional anti‐cancer therapy. Copyright © 2010 John Wiley & Sons, Ltd.
Evaluation of the impact of arginine–chitosan/DNA nanoparticles on human naive CD4+ T cells
Authors: Liu Lanxia , Bai Yuanyuan , Zhu Dunwan , Song Liping , Wang Hai , Dong Xia , Zhang Hailing , Leng Xigang
Published: November 2010

Previous studies showed that arginine‐conjugated chitosan (ACS)/DNA nanoparticles (ACGN) mediated significantly higher expression of the transgenes when compared with chitosan (CS)/DNA nanoparticles (CGN). However, the interactions between ACGN and immune cells still remain poorly understood. The present study investigated whether ACGN affected the initial differentiation direction of human naive CD4+ T cells, either directly or indirectly. It was demonstrated that both ACGN and CGN induced slightly higher production of IL‐12 by THP‐1 cells in the order of ACGN > CGN. However, this macrophage stimulating activity was much less significant when compared with lipopolysaccharide and did not impact on the differentiation of the naive CD4+ T cells separated from the nanoparticles and THP‐1 cells by a 0.1‐μm diameter polycarbonate semipermeable membrane, which allows the pass through of macromolecules including IL‐12. It also demonstrated that, when directly exposed to naive CD4+ T cells, none of the nanoparticles induced either the activation of the naive CD4+ T cells in the absence of recombinant human IL‐4 (rhIL‐4) or IFN‐γ (rhIFN‐γ) that induce naive CD4+ T cell polarization or any changes in the differentiation direction of the naive CD4+ T cells in the presence of the corresponding cytokines. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Perspectives and potential applications of nanomedicine in breast and prostate cancer
Authors: Liu Yang , Solomon Metasebya , Achilefu Samuel
Published: November 2010

Nanomedicine is a branch of nanotechnology that includes the development of nanostructures and nanoanalytical systems for various medical applications. Among these applications, utilization of nanotechnology in oncology has captivated the attention of many research endeavors in recent years. The rapid development of nano‐oncology raises new possibilities in cancer diagnosis and treatment. It also holds great promise for realization of point‐of‐care, theranostics, and personalized medicine. In this article, we review advances in nano‐oncology, with an emphasis on breast and prostate cancer because these organs are amenable to the translation of nanomedicine from small animals to humans. As new drugs are developed, the incorporation of nanotechnology approaches into medicinal research becomes critical. Diverse aspects of nano‐oncology are discussed, including nanocarriers, targeting strategies, nanodevices, as well as nanomedical diagnostics, therapeutics, and safety. The review concludes by identifying some limitations and future perspectives of nano‐oncology in breast and prostate cancer management. © 2010 Wiley Periodicals, Inc. Med Res Rev
Colonic availability of polyphenols and D‐(−)‐quinic acid after apple smoothie consumption
Authors: Hagl Stephanie , Deusser Hannah , Soyalan Buelent , Janzowski Christine , Will Frank , Dietrich Helmut , Albert Franz Werner , Rohner Simone , Richling Elke
Published: November 2010

Scope: The aim of this study was to determine the amounts of polyphenols and D‐(−)‐quinic acid reaching the ileostomy bags of probands (and thus the colon in healthy humans) after ingestion of apple smoothie, a beverage containing 60% cloudy apple juice and 40% apple puree.

Methods and results: Ten healthy ileostomy subjects each ingested 0.7 L of apple smoothie (a bottle). Their ileostomy bags were collected directly before and 1, 2, 4, 6 and 8 h after smoothie consumption, and the polyphenol and D‐(−)‐quinic acid contents of the ileostomy fluids were examined using HPLC‐DAD and HPLC‐MS/MS. The total polyphenol and D‐(−)‐quinic acid content of the apple smoothie was determined to be 1955.6±124.6 mg/0.7 L, which is very high compared to cloudy apple juices. The most abundant substances found in the ileostomy bags were oligomeric procyanidins (705.6±197.9 mg), D‐(−)‐quinic acid (363.4±235.5 mg) and 5‐caffeoylquinic acid (76.7±26.8 mg). Overall recovery of ingested polyphenols and D‐(−)‐quinic acid in the ileostomy bags was 63.3±16.1%.

Conclusions: The amounts of polyphenol and D‐(−)‐quinic acids reaching the ileostomy bags are considerably higher after apple smoothie consumption than after the consumption of cloudy apple juice or cider. These results suggest that the food matrix might affect the colonic availability of polyphenols, and apple smoothies could be more effective in the prevention of chronic colon diseases than both cloudy apple juice and apple cider.
Extant health behaviors and uptake of standardized vs tailored health messages among cancer survivors enrolled in the FRESH START trial: a comparison of fighting‐spirits vs fatalists
Authors: Wilkinson Anna V. , Barrera Stephanie L. , McBride Colleen M. , Snyder Denise C. , Sloane Richard , Meneses Karen M. , Pekmezi Dorothy , Kraus William E. , Demark‐Wahnefried Wendy
Published: November 2010

Objective: Cancer coping styles have been associated with several cancer‐related outcomes. We examined whether baseline lifestyle behaviors differed between cancer survivors with fatalistic vs fighting‐spirit coping styles, and whether there was differential response to two diet‐exercise mailed‐print interventions, one standardized and another individually tailored.

Methods: Baseline differences by coping style are presented for 628 breast and prostate cancer survivors who participated in the FRESH START trial, along with multivariable analyses on rates of uptake by coping style and arm assignment for those completing the 2‐year trial.

Results: At baseline, several differences were observed between fighting‐spirits and fatalists, with the former significantly more likely to be white, younger, leaner, more‐educated and at risk for depression, and less likely to consume 5+fruits and vegetables (F&V)/day (p‐values<0.05). Improvements in physical activity were observed, with fighting‐spirits exhibiting the greatest gains from baseline to Year‐1, regardless of intervention type; but by Year‐2, these differences diminished as fatalists gained ground. Moreover, fatalists who received standardized intervention material also charted steady improvements in F&V intake over the study period; by Year‐2, 58.1% of fatalists achieved the 5‐a‐day goal vs 44.6% of fighting‐spirits (p‐value<0.05).

Conclusions: Lifestyle behaviors and health message uptake differs by cancer coping style. Although tailored interventions appear most effective and minimize differential uptake, standardized interventions also can improve behaviors, though fighting‐spirits may require additional boosters to maintain change. Copyright © 2010 John Wiley & Sons, Ltd.
Designing of stop band filters using hybrid periodic/quasi‐periodic one‐dimensional photonic crystals in microwave domain
Authors: Ali Naim Ben , Kanzari Mounir
Published: November 2010

Using the transfer matrix method approach (TMM), the present paper attempts to determine the transmission properties of generalized quasi‐periodic (GQP) photonic systems. In addition, it studies hybrid periodic photonic/generalized quasi‐periodic photonic (PP/GQP) multilayer structures constructed as alternation of high‐low contrast (Roger and Air) of refractive indices. The quasi‐periodic photonic crystals (PCs) used in these hybrid hetero‐structures are the generalized Fibonacci sequence GF (m, n) and the generalized Thue–Morse sequence GTM (m, n) (m and n are integers). The results are presented in microwave domain for normal incident wave. By varying the parameters m and n of the quasi‐periodic structures, the corresponding transmission spectrum exhibits interesting properties.
An SKP and EIS investigation of amine adsorption on zinc oxide surfaces
Authors: Nazarov A. , Thierry D. , Volovitch P. , Ogle K.
Published: November 2010

A metal/oxide/polymer ‘interphase’ with mixed organic–inorganic nature insures the high stability and the strength of the adhesive joints in a variety of corrosive environments. To model the interaction of epoxy resin with a metal surface, the interaction of amines of different structure with oxidized zinc surfaces was studied by Scanning Kelvin Probe (SKP), FTIR microscopy in atmospheric conditions, and a.c. and d.c. electrochemical techniques in the aqueous electrolyte. It was shown that bidentate ligand‐ethylendiamine, forming stable chelate complexes reacts with zinc oxide with redeposition of the interphase. In air and water electrolyte, this ligand shifts the potential of Zn/ZnO electrode to the level of the oxide‐free zinc. The amines with low chelating property show low effect on the potential of Zn/ZnO. The SKP was used to measure the potential drop at epoxy resin/zinc interface. On this basis, SKP is proposed as a sensitive nondestructive technique to characterize in situ the interaction of the resin with the metal and the subsequent formation of the interphase in the metal–polymer joints. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of Fatty Oil of Zizyphi spinosi semen Obtained by Supercritical Fluid Extraction
Authors: Wang Feng , Liu Xuesong , Chen Yong , Wang Longhu
Published: November 2010

Zizyphi spinosi semen (ZSS) has been widely used for treatment of insomnia in oriental countries. The aim of this study is to characterize the fatty oil of ZSS obtained by supercritical fluid extraction in terms of chemical composition and physicochemical properties. The chemical composition, including fatty acids and unsaponifiable constituents, was analyzed by gas chromatography–mass spectrometer (GC–MS). The results revealed that 9‐octadecenoic acid (43.38 ± 0.03%) and 9,12‐octadecadienoic acid (40.58 ± 0.03%) were the main fatty acids, and β‐sitosterol (37.39 ± 0.02%) and squalene (30.79 ± 0.01%) were the key unsaponifiables. Furthermore, four indexes were assayed according to Chinese Pharmacopeia (2005) to reflect the physicochemical properties of ZSS oil, their values being determined as follows: acid value (10.3 ± 0.1 mg KOH/g), peroxide value (0.05 ± 0.01 g/100 g), saponification value (194.4 ± 0.5 mg KOH/g) and iodine value (109.7 ± 0.8 g I/100 g). The basic information obtained provides data support for quality evaluation and efficacy research of ZSS oil, and suggests its prospects for development in pharmaceutical and food industries.
Rectal duplication cyst in a cat
Authors: Kook Peter H. , Hagen Regine , Willi Barbara , Ruetten Maja , Venzin Claudio
Published: November 2010

Enteric duplication is a rare developmental malformation in people, dogs and cats. The purpose of the present report is to describe the first case of a rectal duplication cyst in a 7-year-old domestic shorthair cat presenting for acute constipation and tenesmus. On rectal palpation a spherical mass compressing the lumen of the rectum could be felt in the dorsal wall of the rectum. A computed tomography (CT) scan confirmed the presence of a well demarcated cystic lesion in the pelvic canal, dorsal to the rectum. The cyst was surgically removed via a perineal approach. No communication with the rectal lumen could be demonstrated. Histopathological examination was consistent with a rectal duplication cyst. Clinical signs resolved completely after excision of this conjoined non-communicating cystic rectal duplicate.
N‐Myc is a downstream target of RET signaling and is required for transcriptional regulation of p18Ink4c by the transforming mutant RETC634R
Authors: Kulkarni Mandar V. , Franklin David S.
Published: November 2010

Inherited activating mutations in RET predispose humans to Multiple Endocrine Neoplasia type‐2 (MEN2). The MEN2A‐specific mutation RETC634R, RET2A, has been shown to simultaneously downregulate the CDKIs p18 and p27, and upregulate cyclin D1. Importantly, the loss of p18 is necessary and sufficient for RET2A‐mediated hyperproliferation. The loss of N‐Myc in mice results in embryonic lethality due to a lack of neuronal progenitor cells that fail to proliferate, correlate with accumulation of p18 and p27. Therefore, N‐Myc may regulate expression of both CDKIs. Also, N‐Myc is expressed predominantly in neuroendocrine cells that give rise to the primary cell types affected in MEN2A. Together these studies suggest that N‐Myc is a downstream target of RET2A signaling that prevents accumulation of p18 and/or p27. We report that MAPK activation by RET2A leads to a transient induction of N‐Myc mRNA and protein levels, and that N‐Myc induction is required to maintain low p18 and p27 levels. Induced N‐Myc levels correlate with increased binding of N‐Myc to an initiator consensus binding site in the p18 promoter, and this binding is essential for RET2A‐mediated transcriptional regulation of p18. Finally, loss of N‐Myc induction prevents RET2A‐mediated hyperproliferation. Our results demonstrate for the first time that N‐Myc is a downstream target of RET2A signaling, and propose that induction of N‐Myc by RET2A is a key step leading to lower p18 levels during MEN2A tumorigenesis.
Surgical management of troublesome mastoid cavities
Authors: Yung M , Tassone P , Moumoulidis I , Vivekanandan S
Published: November 2010

Objective:

To examine the reasons for discharging mastoid cavities, the operative findings during revision surgery, and the medium-term outcome.

Patients:

One hundred and forty revision mastoidectomies in 131 patients were studied. Post-operatively, patients were followed up at three, six and 12 months and then yearly.

Intervention:

A variety of techniques were performed. Over 80 per cent of ears were treated with mastoid obliteration. Concomitant hearing restorative procedures were carried out in one-third of the ears.

Results:

The mastoid cavities were troublesome because of large cavity size, bony overhang, residual infected mastoid cells, the presence of cholesteatoma or perforations, and/or inadequate meatoplasty. One year after revision mastoidectomy, over 95 per cent of the ears had become completely ‘dry’ and water-resistant. Overall, 50.9 per cent of the ears had a 12-month post-operative air–bone gap of 20 dB or less.

Conclusion:

Revision mastoidectomy has a high success rate in converting troublesome mastoid cavities into dry, water-resistant ears.
The effect of outliers on the perception of sound change
Authors: Labov William , Baranowski Maciej , Dinkin Aaron
Published: November 2010

The role of outliers in vowel distributions is examined through an experiment that registers subjects' assessments of symmetrical and asymmetrical distributions. Subjects first scaled their subjective impressions of a series of six resynthesized tokens of the word bad ranging from low front to upper mid front. They were then asked to register on this scale their overall impressions of four series of five phrases including bad: low symmetrical, low with a very low outlier, high symmetrical, high with a very high outlier. Subjects show the capacity to integrate outliers into their overall assessments in a manner consistent with their acoustic properties. The effect of low outliers was significantly greater, reflecting the socially marked status of this form in the Philadelphia community.
Maya Resistance, Maya Resolve:The tools of autonomy from Tipu, Belize
Authors: Simmons Scott E.
Published: November 2010

This paper summarizes the results of an analysis of the formal stone tools from the Maya site of Tipu, Belize. The lithic tools are dominated by one form, the small, side-notched projectile point. These tools were recovered from Colonial-period contexts at the site. These points were manufactured from prismatic blade and flake blanks and were fairly uniform in terms of their size and method of manufacture, although distinct base styles were observed. A brief discussion of both quantitative and qualitative attributes and a description of the technology used in the manufacture of these points are presented. Also, several ideas on how researchers may be able to see ethnic or subethnic expressions of style in Colonial-period tools is offered. The possible functions of these projectile points is discussed using information from different sources. The use of these small projectile points, a component of bow-and-arrow technology, will be discussed in light of the often hostile nature of the Spanish Conquest, and in particular, the conquest and reconquest of the Tipu area.
The Incienso Throne and Other Thrones From Kaminaljuyu, Guatemala. Late Preclassic examples of a Mesoamerican throne tradition
Authors: Kaplan Jonathan
Published: November 2010

A “table altar,” perhaps one described by Cabrera (1822) almost 200 years ago and since unreported, is the only complete example of a class of four-legged sculptures known at present from Kaminaljuyu. Iconographic similarities between the monument and sculptures from southern piedmont and coastal centers and comparisons with other Kaminaljuyu sculptures suggest an early Late Preclassic date (Late Verbena-Early Arenal, approximately 300-200 B.C.). According to depictions on other southern-area monuments many “table altars” were formal, emblematic seats for rulers, or thrones, which had specific ideologies associated with them Review of monuments, including identification as a four-legged throne of the well-known sculpture, Stela 10, numbers the Kaminaljuyu corpus of thrones to date at a minimum of seven. The presence of thrones as a sculptural class at Kaminaljuyu in the Late Preclassic period provides more evidence of a long throne tradition reaching from Olmec times through the Maya Classic and into the Postclassic. Kaminaljuyu's thrones conceivably also add to other evidence of complex sociopolitics at the city during the Late Preclassic.
OH and OI airglow layer modulation by ducted short‐period gravity waves: Effects of trapping altitude
Authors: Snively Jonathan B. , Pasko Victor P. , Taylor Michael J.
Published: November 2010

Perturbations to the OH and OI [O(1S) 557.7 nm] airglow layers by ducted gravity waves near the Brunt‐Väisälä period are investigated using a 2‐D numerical model. Airglow signatures of these waves are strongly determined by perturbations of O, O3, and H, which exhibit peak densities near and above mesopause. Strong periodic vertical wind components of short‐period gravity waves induce opposite relative density perturbations above and below the layer density peaks. Airglow signatures for ducted waves depend on the specific vertical shapes and altitudes of the wave packets relative to ambient species density profiles; waves perturbing only the bottoms or tops of the layers produce signatures differing from those able to perturb the entire layer thickness. Line‐of‐sight cancellation occurs between opposite perturbations above and below airglow layer peaks, even for standing waves without vertical phase progression. Integrated brightness‐weighted temperature and intensity can thus appear in‐phase or antiphase for standing waves, depending on the wave‐packet altitude relative to the density gradients. Comparisons of OH and OI layer intensities also reveal in‐phase or antiphase relative intensity responses and do not directly indicate the phase of the wave perturbations at layer peak altitudes. Despite this ambiguity, simultaneous brightness‐weighted temperature measurements may provide additional insight into wave structure, amplitude, and trapping altitude. For waves of sufficient amplitude that perturb steep density gradients, nonlinearity of the airglow response may be observable; this effect is most prominent when strong cancellation of the linear signature occurs.
Modeling Pinus edulis growth in a changing climate: Carbon dioxide, growing season length, and precipitation
Authors: Tysor Susannah , Koch George , Whipple Amy
Published: November 2010

Background/Question/Methods

Pinus edulis (pinyon pine) is a foundation tree species in the southwestern United States that has experienced high levels of mortality in a drought extending from the mid-1990s to the present. Despite high mortality levels, radial growth of pinyon pine in northern Arizona over the past century shows an increasing trend not found in four centuries of preindustrial growth. Atmospheric carbon dioxide concentration ([CO2]) shows a strong correlation with recent radial growth, and a simple linear AR(1) model with only [CO2] as a covariate explains average yearly growth well. No climate variable except [CO2] has a consistent long-term trend that accounts for increasing radial growth, but growing season and precipitation are responsible for interannual variation in radial growth. Our goal is to understand how [CO2] and other climate variables, including drought severity, influence growth and survival of pinyon pine.

Results/Conclusions

To model and predict growth for individual pinyon pine trees, we adapted a hierarchical Bayesian state-space model from Clark et al. (2007) that incorporates both tree ring and diameter data. We included [CO2], water year precipitation, and an index of growing season length based on temperatures early and late in the growing season as covariates while adjusting for known size-related growth trends. Elevated [CO2], longer growing season, and wetter years are positively correlated with growth (parameter values and standard errors of 0.010 ± 0.000039, 0.0096 ± 0.000082, and 0.010 ± 0.000035, respectively). These trends are consistent with recent studies of growth patterns in other long-lived tree species in the western U.S. Ongoing analyses are evaluating interactions between [CO2] and precipitation to test the idea that rising CO2 may ameliorate growth reductions due to water stress.
Best practices for building interoperable systems for translational research
Authors: Kibbe Warren
Published: November 2010

Research databases, clinical systems, and lab systems all have different standards, formats and drivers for data capture, operation, analysis and integration. For interdisciplinary nutritional researchers, however, there is a dependence on all of these areas and technologies. While building and integrating these systems can be difficult, using agile practices including short iterations, testing and continuous integration methods, and close engagement with all stakeholders to create useful systems for translational research. Interoperability also requires good data standards, including the use of structured data dictionaries and existing data standards such as HL7, UMLS, LOINC, ICD, and OBO foundry ontologies.
Ecology of Environmental Education: Feedbacks, Education, and Resilience
Authors: Tidball Keith G , Krasny Marianne
Published: November 2010

The ecology education community has focused on the suite of knowledge and competencies that constitute environmental literacy, including self-knowledge, evidence-based habits of mind, and ecological concepts and connections (Jordan et al., 2009). Whereas the environmental education (EE) community also is concerned with knowledge, it further embraces goals related to changing attitudes and behavior. In both of these sub-disciplines, educational researchers most often focus on outcomes of specific interventions. Less attention has been paid to the interrelations among the ecological or environmental education activities themselves and the larger social-ecological system. This poster will explore the notion of an ecology of EE, and will attempt to situate EE within a social-ecological framework, such as those proposed by Grimm, Pickett and other ecological researchers who focus on coupled human-natural systems.Using civic ecology education as an example, we explore the interrelations among an educational program and the social and bio-geo-physical components of a larger system. Civic ecology education refers to youth programs where learning is situated in community gardening, community forestry, habitat restoration, and similar small-scale, emergent environmental stewardship or civic ecology practices, which have both social and ecological outcomes. When an educational program is situated in these practices, it may become part of a virtuous feedback loop, in which youth and adult stewardship actions contribute to natural capital, which in turn produces ecosystem services. Social capital may also be enhanced through multiple mechanisms, e.g., youth and adult participation in the civic ecology activity, and through the green spaces created through their activity, both of which provide opportunities for people to socialize, build trust, and participate in the civic life of their community. In addition to viewing EE’s role in feedback loops, we consider EE as a driver of human behavior, as a mediator of human impact on the social and bio-physical environment, and as a mediator of the way in which humans use ecosystem services.Should EE situated in civic ecology practice contribute both directly and indirectly to social and natural capital and ecosystem services, then it may play a role in social-ecological systems resilience. Here we show management and educational applications for a conceptual framework focusing on EE’s role in social-ecosystems and their resilience.
Citizen Science in Disaster and Conflict Resilience
Authors: Tidball Keith G , Krasny Marianne
Published: November 2010

Background/Question/Methods

Within the disaster and conflict response communities, concern about lack of effectiveness of outside responses has led to a debate about the role of local people in developing the capacity to prepare for a crisis and to respond after calamity has struck. Pelling (2007) points out the potential for participatory disaster risk assessment to build local capacity and for generating knowledge that, along with more expert-driven data collection, is used to identify and reduce the risk of disaster. Similarly, Weinstein and Tidball (2007) and Tidball et al. (2008) present an alternative model for post-crisis intervention based on local assets, including ongoing attempts of communities to manage their natural resources. For example, these authors suggest that civic ecology (CE) practices, including community forestry, watershed enhancement, community agriculture and gardening, and other participatory environmental restoration initiatives that emerge from the actions of local residents (Tidball and Krasny 2007), should be examined and perhaps leveraged by outsiders for their ability to mitigate post-crisis situations. The question is, how might CE relate to citizen science in applications post-disaster or conflict?

Results/Conclusions

CE practices emerge through the actions of people wanting to manage a local resource, and integrate both learning through small-scale experimentation and observations (adaptive management) and collaborative or participatory processes (co-management). They can be considered as an emergent form of adaptive co-management (Ruitenbeek and Cartier 2001; Armitage, Plummer et al. 2009). The local knowledge of individuals who initiate the practices is critical, although often linkages are made with scientists from universities, government, and non-profit organizations, so multiple forms of knowledge are incorporated into the stewardship activities. This learning shortens feedback times between management actions, such as participatory approaches for planting trees, and seeing the impact of tree planting on local ecological and social systems. CE practices embody attributes that may foster resilience both prior to and post-crisis, including multiple forms of knowledge and governance, self-organization, adaptive learning, shorter feedbacks, and ecosystem services (Folke, S. Carpenter et al. 2002; Walker and Salt 2006). We demonstrate that similar to CE, citizen science could build capacity to mitigate disaster and conflict through shortening feedbacks and through making available multiple forms of knowledge and data collection. Further, given the need for asset-based and participatory interventions post-crisis, and the paucity of existing mechanisms that address this need (Weinstein and Tidball 2007), we examine citizen science and its potential to become part of a tool kit of participatory responses that engage citizens in meaningful activity post-conflict.
Diodelike and resistive hysteresis behavior of heterolayered BiFeO3/ZnO ferroelectric thin films
Authors: Wu Jiagang , Wang John
Published: November 2010

BiFeO 3 / ZnO , ZnO/BiFeO3, BiFeO3/ZnO/BiFeO3, and ZnO/BiFeO3/ZnO thin film heterostructures were deposited on SrRuO3/Pt(111)/TiO2/SiO2/Si(100) substrates by off-axis radio frequency sputtering. Their diodelike and resistive hysteresis behavior are dependent on the combination sequence of the constituent layers in the heterostructures. Both the diodelike and resistive hysteresis behavior were clearly observed in BiFeO3/ZnO and ZnO/BiFeO3. The phenomena became more apparent with rising temperature. The behavior arises from the interface formed between BiFeO3 and ZnO. As expected, the diodelike and resistive hysteresis behavior are weakened and almost disappeared in the case of BiFeO3/ZnO/BiFeO3 and ZnO/BiFeO3/ZnO, where the two interfaces are equal and opposite to each other. The interface-limited Fowler–Nordheim tunneling in the high electric field region is demonstrated to involve in the formation of resistive hysteresis.
Simulations of one- and two-dimensional complex plasmas using a modular, object-oriented code
Authors: Jefferson R. A. , Cianciosa M. , Thomas E.
Published: November 2010

In a complex plasma, charged microparticles (“dust”) are added to a background of ions, electrons, and neutral particles. This dust fully interacts with the surrounding plasma and self-consistently alters the plasma environment leading to the emergence of new plasma behavior. Numerical tools that complement experimental investigations can provide important insights into the properties of complex plasmas. This paper discusses a newly developed code, named DEMON (dynamic exploration of microparticle clouds optimized numerically), for simulating a complex plasma. The DEMON code models the behavior of the charged particle component of a complex plasma in a uniform plasma background. The key feature of the DEMON code is the use of a modular force model that allows a wide variety of experimental configurations to be studied without varying the core code infrastructure. Examples of the flexibility of this modular approach are presented using examples of one- and two-dimensional complex plasmas.
Characterization of complementary patterned metallic membranes produced simultaneously by a dual fabrication process
Authors: Hao Qingzhen , Zeng Yong , Wang Xiande , Zhao Yanhui , Wang Bei , Chiang I-Kao , Werner Douglas H. , Crespi Vincent , Huang Tony Jun
Published: November 2010

An efficient technique is developed to fabricate optically thin metallic films with subwavelength patterns and their complements simultaneously. By comparing the spectra of the complementary films, we show that Babinet’s principle nearly holds for these structures in the optical domain. Rigorous full-wave simulations are employed to verify the experimental observations. It is further demonstrated that a discrete-dipole approximation can qualitatively describe the spectral dependence of the metallic membranes on the geometry of the constituent particles as well as the illuminating polarization.
Coherent controlling plasmon transport properties in metal nanowire coupled to quantum dot
Authors: Cheng Mu-Tian , Luo Ya-Qin , Wang Pei-Zhen , Zhao Guang-Xing
Published: November 2010

We investigate theoretically the transport properties of surface plasmon in a metal nanowire with linear and nonlinear dispersion relations coupled to a quantum dot with three levels in cascaded configuration by full quantum-mechanical approach. The transmission and reflection amplitudes are obtained. The reflection spectrum shows two peaks for the surface plasmon with linear dispersion relation while it can exhibit four peaks when the plasmon has quadratic dispersion relation. The calculations reveal that one can control the plasmon transport properties by adjusting Rabi frequency and circular frequency of a classic optical field.
In situ synchrotron x-ray characterization of ZnO atomic layer deposition
Authors: Fong D. D. , Eastman J. A. , Kim S. K. , Fister T. T. , Highland M. J. , Baldo P. M. , Fuoss P. H.
Published: November 2010

The utility of in situ synchrotron x-ray scattering and fluorescence in gaining insight into the early stages of the atomic layer deposition process is demonstrated in this study of ZnO growth on Si. ZnO films are found to initially grow as islands, with the onset of coalescence occurring during the fourth growth cycle. The start of coalescence is accompanied by a small increase in surface roughness. After ten cycles of growth, the growth rate decreases from 4.2 to 3.0 Å per cycle, with the growth following expected self-limiting behavior. The overall growth process is consistent with the model of Puurunen and Vandervorts for substrate-inhibited growth [R. L. Puurunen and W. Vandervorst, J. Appl. Phys. 96, 7686 (2004)].
Dangling bond charge transition levels in AlAs, GaAs, and InAs
Authors: Komsa Hannu-Pekka , Pasquarello Alfredo
Published: November 2010

Charge transition levels of dangling bonds in III–V semiconductors (AlAs, GaAs, and InAs) are determined via hybrid density-functional calculations. In GaAs, the Ga and As levels are found at 0.28 eV below the conduction band and at 0.16 eV above the valence band, respectively, in good correspondence with measured levels. These defect levels line up across the present semiconductor series for a band alignment based on experimental offsets. For In0.53Ga0.47As, both the In and Ga levels are inferred to resonate with the conduction band while the As level remains in the gap at 0.1 eV from the valence band.
Terahertz intersubband absorption in GaN/AlGaN step quantum wells
Authors: Machhadani H. , Kotsar Y. , Sakr S. , Tchernycheva M. , Colombelli R. , Mangeney J. , Bellet-Amalric E. , Sarigiannidou E. , Monroy E. , Julien F. H.
Published: November 2010

We demonstrate terahertz intersubband absorptions at frequencies of 2.1 THz (λ≈143 μm) and 4.2 THz (λ≈70 μm) in nitride-based semiconductor quantum wells. The structures consist of a 3 nm thick GaN well, an Al0.05Ga0.95N step barrier, and a 3 nm thick Al0.1Ga0.9N barrier. The absorption is detected at 4.7 K. The structure design has been optimized to approach a flat-band potential in the wells to allow for an intersubband absorption in the terahertz frequency range and to maximize the optical dipole moments.
Ionization energy levels in C-doped InxGa1−xN alloys
Authors: Tablero C.
Published: November 2010

The InxGa1−xN alloys present levels as a result of the intentional (doped) or unintentional (contamination) introduction of C atoms into the host semiconductor. The III-V nitride semiconductors and their alloys usually crystallize in the wurtzite structure although the zinc blende structure has also been grown. We obtained the InxGa1−xN:C ionization energies from first-principles calculations of the two ordered wurtzite and zinc blende structures using different exchange and correlation terms. In accordance with the experimental results, the ionization levels could give rise, on some occasions, to a metallic impurity band.
Dynamics of α-helical subdomain rotation in the intact maltose ATP-binding cassette transporter
Authors: Orelle Cédric , Alvarez Frances Joan D. , Oldham Michael L. , Orelle Arnaud , Wiley Theodore E. , Chen Jue , Davidson Amy L.
Published: November 2010

ATP-binding cassette (ABC) transporters are powered by a nucleotide-binding domain dimer that opens and closes during cycles of ATP hydrolysis. These domains consist of a RecA-like subdomain and an α-helical subdomain that is specific to the family. Many studies on isolated domains suggest that the helical subdomain rotates toward the RecA-like subdomain in response to ATP binding, moving the family signature motif into a favorable position to interact with the nucleotide across the dimer interface. Moreover, the transmembrane domains are docked into a cleft at the interface between these subdomains, suggesting a putative role of the rotation in interdomain communication. Electron paramagnetic resonance spectroscopy was used to study the dynamics of this rotation in the intact
Escherichia coli
maltose transporter MalFGK
2
. This importer requires a periplasmic maltose-binding protein (MBP) that activates ATP hydrolysis by promoting the closure of the cassette dimer (MalK
2
). Whereas this rotation occurred during the transport cycle, it required not only trinucleotide, but also MBP, suggesting it is part of a global conformational change in the transporter. Interaction of AMP-PNP-Mg
2+
and a MBP that is locked in a closed conformation induced a transition from open MalK
2
to semiopen MalK
2
without significant subdomain rotation. Inward rotation of the helical subdomain and complete closure of MalK
2
therefore appear to be coupled to the reorientation of transmembrane helices and the opening of MBP, events that promote transfer of maltose into the transporter. After ATP hydrolysis, the helical subdomain rotates out as MalK
2
opens, resetting the transporter in an inward-facing conformation.