bluuebunny/crossref_metadata_2025 huggingface dataset:
Genesis of upland soils, Lewes Plateau, central Yukon. Part 2: Soils formed in weathered granitic bedrock
Authors: Dampier Lesley , Sanborn Paul , Smith Scott , Bond Jeffrey , J. Clague John
Published: July 2011

Dampier, L., Sanborn, P., Smith, S., Bond, J. and Clague, J. J. 2011. Genesis of upland soils, Lewes Plateau, central Yukon. Part 2: Soils formed in weathered granitic bedrock. Can. J. Soil Sci. 91: 579–594. Polygenetic soils have formed on weathered granitic bedrock at high elevation (>1200 m asl) beyond the penultimate glacial limit on the Lewes Plateau in central Yukon Territory. Solum thickness in four Brunisols that were examined exceeds the depths of excavated pits (85–110 cm), but data indicate limited chemical weathering. Clay mineralogy is dominated by vermiculite and kaolinite. Smectite and chlorite are present in horizons derived, respectively, from residuum and colluvium. Sola are strongly cryoturbated, in spite of the lack of permafrost at these sites today. Three scenarios are proposed to explain these soils: preservation of relict soil features beneath cold-based ice, prolonged interglacial soil formation following erosion of till deposited by warm-based ice, and ice-free conditions throughout the Quaternary, with soil evolution shaped by multiple glacial-interglacial cycles.
Comportamento de busca na internet: um estudo exploratório em salas comunitárias
Authors: Furnival Ariadne Chlöe Mary , Abe Veridiana
Published: July 2011

Estudo sobre o comportamento de busca de informação dos usuários das salas de Internet existentes em duas instituições numa cidade do interior do estado de São Paulo, que promovem o acesso gratuito à comunidade, assim contribuindo ativamente ao processo de inclusão digital. A análise do comportamento de busca de informação dos usuários visou identificar a estratégia global de busca empregada, compreendendo a utilização da sintaxe e semântica de busca, as fontes de informação e os usos da Internet. Foram aplicados 61 questionários com perguntas fechadas e abertas e os resultados permitem afirmar que os usuários possuem pouca familiaridade com a Internet, efetuam em média 1 a 2 buscas e empregam poucos termos na formulação da expressão de busca, ainda que recuperem as informações que necessitam.
Reflexões sobre as influências do capitalismo no campo da Biblioteconomia e Ciência da informação
Authors: Maimone Giovana Deliberali , Silveira Naira Christofoletti , Tálamo Maria de Fátima Gonçalves Moreira
Published: July 2011

Apresenta relações entre as diversas fases do ensino de Biblioteconomia e Ciência da Informação no Brasil e o capitalismo. Para evidenciar tais relações exibe-se o modo de produção apitalista e suas respectivas etapas, contextualizando dessa forma a influência deste na área e na formação do profissional da informação. As relações entre o Capitalismo e o ensino da Biblioteconomia permitem desenvolver reflexões acerca dos modelos e conteúdos dos cursos ministrados na área. Tal entendimento do modo de articulação dos parâmetros curriculares reflete as concepções e valores em período temporal. Por fim, questões de cunho terminológico são feitas a título de exemplificar as comparações mencionadas.
Mediação e convergência em bibliotecas acadêmicas: saberes e práticas culturais
Authors: Bufrem Leilah Santiago , Sorribas Tidra Viana
Published: July 2011

Analisa as possibilidades de uma cultura informacional nas bibliotecas universitárias brasileiras para a construção de um ambiente propício à formação de saberes, estabelecendo cinco categorias relativas à problemática levantada: o contexto; os fenômenos da mediação e da convergência relacionados às bibliotecas acadêmicas; os sujeitos no processo; as relações de força e a articulação entre esses fatores. Conclui que as bibliotecas têm o poder de conjugar as práticas investigativas para a construção dos saberes, não apenas como integrantes da cultura universitária, mas como sujeitos de sua construção.
Estudos métricos da informação: primeiras aproximações
Authors: Noronha Daisy Pires , Maricato João de Melo
Published: July 2011

Apresentam-se alguns conceitos e considerações fundamentais dos estudos métricos da informação e os principais métodos e técnicas utilizadas, como a bibliometria, cienciometria, informetria, webmetria, patentometria e biblioteconometria. Discute-se o ciclo de comunicação científica, destacando-se os principais indicadores de input (insumo) e output (produto), assim como, a importância da publicação dos resultados da pesquisa científica e do processo de avaliação pelos pares. Comentam-se algumas características e aplicações das leis bibliométricas e de outros recursos utilizados nos estudos métricos da informação.
Transformer l’information en connaissance avec stanalyst. Cadre conceptuel et modele
Authors: Polanco Xavier
Published: July 2011

STANALYST : A quoi sert-il ? Comment est-il fait ? A quelle conception réponde-t-il ? Nous allons essayer de donner réponse à ces trois questions nous situant dans Le contexte de la science de l’information. Ici nous nous concentrons essentiellement sur La fonction et la conception qui sont à la base de STANALYST en laissant de côté son mode d’emploi. Ce n’est pas un discours technologique au sens de rester exclusivement au niveau de la description d’une technologie de l’information. Au contraire, la tache que nous nous imposons est de placer la technologie dans le cadre d’une certaine conception du travail sur l’information. Notre sujet central est démontrer qu’est-ce que l’analyse de l’information et comment nous pouvons réaliser cette analyse avec un outil conçu pour produire une information élaborée, et plus encore pour transformer l’information en connaissances. L’intérêt du sujet est encore plus sensible à l’heure actuelle où la société est reconnue comme société de l’information, et l’on estime em outre que celle-ci évolue vers une société de la connaissance.
A spectral method for retrieving cloud optical thickness and effective radius from surface-based transmittance measurements
Authors: McBride P. J. , Schmidt K. S. , Pilewskie P. , Kittelman A. S. , Wolfe D. E.
Published: July 2011

Abstract. We introduce a new spectral method for the retrieval of optical thickness and effective radius from cloud transmittance that relies on the spectral slope of the normalized transmittance between 1565 nm and 1634 nm, and on cloud transmittance at a visible wavelength. The standard dual-wavelength technique, which is traditionally used in reflectance-based retrievals, is ill-suited for transmittance because it lacks sensitivity to effective radius, especially for optically thin clouds. Using the spectral slope rather than the transmittance itself enhances the sensitivity of transmittance observations with respect to the effective radius. This is demonstrated by applying it to the moderate spectral resolution observations from the Solar Spectral Flux Radiometer (SSFR) and Shortwave Spectroradiometer (SWS), and by examining the retrieval uncertainties of the standard and the spectral method for data from the DOE ARM Southern Great Plains (SGP) site and a NOAA ship cruise (ICEALOT). The liquid water path (LWP) is derived from the retrieved optical thickness and effective radius, based on two different assumptions about the cloud vertical profile, and compared to the simultaneous observations from a microwave radiometer. Optical thickness and effective radius is also compared to MODIS retrievals. In general, the effective radius uncertainties were much larger for the standard retrieval than for the spectral retrieval, particularly for thin clouds. When defining 2 μm as upper limit for the tolerable uncertainty of the effective radius, the standard method returned only very few valid retrievals for clouds with an optical thickness below 25. For the analyzed ICEALOT data (mean optical thickness 23), the spectral method provided valid retrievals for 84 % of the data (24 % for the standard method). For the SGP data (mean optical thickness 44), both methods provided a high return of 90 % for the spectral method and 78 % for the standard method.
Black carbon emissions from biomass and fossil fuels in rural India
Authors: Rehman I. H. , Ahmed T. , Praveen P. S. , Kar A. , Ramanathan V.
Published: July 2011

Abstract. Black carbon (BC) emission from biofuel cooking in South Asia and its radiative forcing is a significant source of uncertainty for health and climate impact studies. Quantification of BC emissions in the published literature is either based on laboratory or remote field observations far away from the source. For the first time under Project Surya, we use field measurements taken simultaneously inside rural households, ambient air and vehicular emissions from highways in a rural area in the Indo-Gangetic-Plains region of India to establish the role of both solid biomass based cooking in traditional stoves and diesel vehicles in contributing to high BC and organic carbon (OC), and solar absorption. The major finding of this study is that BC concentrations during cooking hours, both indoors and outdoors, have anomalously large twice-daily peak concentrations reaching 60 μg m−3 (median 15-min average value) for indoor and 30 μg m−3 (median 15-min average value) for outdoor during the early morning (05:00 to 08:00) and early evening (17:00 to 19:00) hours coinciding with the morning and evening cooking hours. The BC during the non-cooking hours were also large, in the range of 2 to 30 μg m−3. The peak indoor BC concentrations reached as high as 1000 μg m−3. The large diurnal peaks seen in this study lead to the conclusion that satellite based aerosol studies that rely on once- daily daytime measurements may severely underestimate the BC loading of the atmosphere. The concentration of OC was a factor of 5 larger than BC and furthermore optical data show that absorbing brown carbon was a major component of the OC. The imprint of the cooking hour peaks were seen in the outdoor BC both in the village as well as in the highway. The results have significant implications for climate and epidemiological studies.
Secondary organic aerosol formation from the photooxidation of isoprene, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene under high NOx conditions
Authors: Sato K. , Nakao S. , Clark C. H. , Qi L. , Cocker III D. R.
Published: July 2011

Abstract. Secondary organic aerosol (SOA) formation from atmospheric oxidation of isoprene has been the subject of multiple studies in recent years; however, reactions of other conjugated dienes emitted from anthropogenic sources remain poorly understood. SOA formation from the photooxidation of isoprene, isoprene-1-13C, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene is investigated for high NOx conditions. The SOA yield measured in the 1,3-butadiene/NOx/H2O2 irradiation system (0.089–0.178) was close to or slightly higher than that measured with isoprene under similar NOx conditions (0.077–0.103), suggesting that the photooxidation of 1,3-butadiene is a possible source of SOA in urban air. In contrast, a very small amount of SOA particles was produced in experiments with 2,3-dimethyl-1,3-butadiene. Off-line liquid chromatography – mass spectrometry analysis revealed that the signals of oligoesters comprise a major fraction (0.10–0.33) of the signals of the SOA products observed from all dienes investigated. The oligoesters originate from the unsaturated aldehyde gas phase diene reaction products; namely, semi-volatile compounds produced by the oxidation of the unsaturated aldehyde undergo particle-phase oligoester formation. Oligoesters produced by the dehydration reaction between nitrooxypolyol and 2-methylglyceric acid monomer or its oligomer were also characterized in these experiments with isoprene as the starting diene. These oligomers are possible sources of the 2-methyltetrols found in ambient aerosol samples collected under high NOx conditions. Furthermore, in low-temperature experiments also conducted in this study, the SOA yield measured with isoprene at 278 K was 2–3 times as high as that measured at 300 K under similar concentration conditions. Although oligomerization plays an important role in SOA formation from isoprene photooxidation, the observed temperature dependence of SOA yield is largely explained by gas/particle partitioning of semi-volatile compounds.
Chemical characterization of aerosols at the summit of Mountain Tai in Central East China
Authors: Deng C. , Zhuang G. , Huang K. , Li J. , Zhang R. , Wang Q. , Liu T. , Sun Y. , Guo Z. , Fu J. S. , Wang Z.
Published: July 2011

Abstract. PM2.5 and TSP samples were collected at the summit of Mountain Tai (MT) (1534 m a.s.l.) in spring 2006/2007 and summer 2006 to investigate the characteristics of aerosols over central eastern China. For comparison, aerosol samples were also collected at Tazhong, Urumqi, and Tianchi in Xinjiang in northwestern China, Duolun and Yulin in northern China, and two urban sites in the megacities, Beijing and Shanghai, in 2007. Daily mass concentrations of TSP and PM2.5 ranged from 39.6–287.6 μg m−3 and 17.2–235.7 μg m−3 respectively at the summit of MT. Averaged concentrations of PM2.5 showed a pronounced seasonal variation with higher concentration in summer than spring. 17 water-soluble ions (SO42−, NO3−, Cl−, F−, PO43−, NO2−, CH3COO−, CH2C2O42−, C2H4C2O42−, HCOO−, MSA, C2O42−, NH4+, Ca2+, K+, Mg2+, Na+), and 19 elements of all samples were measured. SO42−, NO3−, and NH4+ were the major water-soluble species in PM2.5, accounting for 61.50 % and 72.65 % of the total measured ions in spring and summer, respectively. The average ratio of PM2.5/TSP was 0.37(2006) and 0.49(2007) in spring, while up to 0.91 in summer, suggesting that aerosol particles were primarily comprised of fine particles in summer and of considerable coarse particles in spring. Crustal elements (e.g., Ca, Mg, Al, Fe, etc.) showed higher concentration in spring than summer, while most of the pollution species (SO42−, NO3−, K+, NO2−, NH4+, Cl−, organic acids, Pb, Zn, Cd, and Cr) from local/regional anthropogenic emissions or secondary formation presented higher concentration in summer. The ratio of Ca/Al suggested the impact of Asian dust from the western deserts on the air quality in this region. The high concentration of K+ in PM2.5 (4.41 μg m−3) and its good correlation with black carbon (r = 0.90) and oxalic acid (r = 0.87) suggested the severe pollution from biomass burning, which was proved to be a main source of fine particles over central eastern China in summer. The contribution of biomass burning to the fine particle at MT accounted for 7.56 % in spring and 36.71 % in summer, and even reached to 81.58 % on a day. As and Pb were two of the most enriched elements. The long-range transport of aerosols spread the heavy pollution from coal-mining/coal-ash to everywhere over China. Anthropogenic air-pollution was evidently rather severe at MT, though it has been declared by UNESCO to be a World Heritage site.
Large Asian dust layers continuously reached North America in April 2010
Authors: Uno I. , Eguchi K. , Yumimoto K. , Liu Z. , Hara Y. , Sugimoto N. , Shimizu A. , Takemura T.
Published: July 2011

Abstract. The NASA space-borne Mie-lidar system CALIPSO/CALIOP revealed that multiple large Asian dust layers with a horizontal scale of 2000–3000 km reached North America, occupying the full troposphere, in April 2010. This kind of dust layer transport has not been reported before. Our analysis of CALIOP data and global aerosol model results revealed that frequent dust emissions occurred in northwestern China because of stronger-than-average near-surface winds, and that strong stable westerly winds carried the Asian dust from northwestern China to the central Pacific Ocean. A negative pressure anomaly was located in the eastern Pacific Ocean, and the main dust transport path was split into two branches: a northern path and a southern path over North America. Northern-path dust was trapped and stagnant for a longer time than southern path dust and finally subsided under a high-pressure system. Dust along the southern path reached the central US. These complex conditions resulted in a multi-layered structure of dust over North America.
Direct and semi-direct radiative forcing of smoke aerosols over clouds
Authors: Wilcox E. M.
Published: July 2011

Abstract. Observations from Earth observing satellites indicate that dark carbonaceous aerosols that absorb solar radiation are widespread in the tropics and subtropics. When these aerosols mix with clouds, there is generally a reduction of cloudiness owing to absorption of solar energy in the aerosol layer. Over the subtropical South Atlantic Ocean, where smoke from savannah burning in southern Africa resides above a persistent deck of marine stratocumulus clouds, radiative heating of the smoke layer leads to a thickening of the cloud layer. Here, satellite observations of the albedo of overcast scenes of 25 km2 size or larger are combined with additional satellite observations of clouds and aerosols to estimate the top-of-atmosphere direct radiative forcing attributable to presence of dark aerosol above bright cloud, and the negative semi-direct forcing attributable to the thickening of the cloud layer. The average positive direct radiative forcing by smoke over an overcast scene is 9.2±6.6 W m−2 for cases with an unambiguous signal of absorbing aerosol over cloud in passive ultraviolet remote sensing observations. However, cloud liquid water path is enhanced by 16.3±7.7 g m−2 across the range of values for sea surface temperature for cases of smoke over cloud. The negative radiative forcing associated with this semi-direct effect of smoke over clouds is estimated to be −5.9±3.5 W m−2. Therefore, the cooling associated with the semi-direct cloud thickening effect compensates for greater than 60 % of the direct radiative effect. Accounting for the frequency of occurrence of significant absorbing aerosol above overcast scenes leads to an estimate of the average direct forcing of 1.0±0.7 W m−2 contributed by these scenes averaged over the subtropical southeast Atlantic Ocean during austral winter. The regional average of the negative semi-direct forcing is −0.7±0.4 W m−2. Therefore, smoke aerosols overlaying the decks of overcast marine stratocumulus clouds considered here yield a small net positive radiative forcing, which results from the difference of two larger effects.
Controls on winter ecosystem respiration in temperate and boreal ecosystems
Authors: Wang T. , Ciais P. , Piao S. L. , Ottlé C. , Brender P. , Maignan F. , Arain A. , Cescatti A. , Gianelle D. , Gough C. , Gu L. , Lafleur P. , Laurila T. , Marcolla B. , Margolis H. , Montagnani L. , Moors E. , Saigusa N. , Vesala T. , Wohlfahrt G. , Koven C. , Black A. , Dellwik E. , Don A. , Hollinger D. , Knohl A. , Monson R. , Munger J. , Suyker A. , Varlagin A. , Verma S.
Published: July 2011

Abstract. Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (Reco) of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter Reco rates (0.90 ± 0.39 g C m−2 d−1), when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter Reco rates (0.02 ± 0.02 g C m−2 d−1). Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter Reco rates (g C m−2 d−1) of 0.70(±0.33), 0.60(±0.38), 0.62(±0.43), 0.49(±0.22) and 0.27(±0.08), respectively. Our cross site analysis showed that winter air (Tair) and soil (Tsoil) temperature played a dominating role in determining the spatial patterns of winter Reco in both forest and managed ecosystems (grasslands and croplands). Besides temperature, the seasonal amplitude of the leaf area index (LAI), inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for Reco in the subsequent winter, played a marginal role in winter CO2 emissions from forest ecosystems. We found that winter Reco sensitivity to temperature variation across space (QS) was higher than the one over time (interannual, QT). This can be expected because QS not only accounts for climate gradients across sites but also for (positively correlated) the spatial variability of substrate quantity. Thus, if the models estimate future warming impacts on Reco based on QS rather than QT, this could overestimate the impact of temperature changes.
Nitrogen impacts on vascular plants in Britain: an analysis of two national observation networks
Authors: Henrys P. A. , Stevens C. J. , Smart S. M. , Maskell L. C. , Walker K. J. , Preston C. D. , Crowe A. , Rowe E. , Gowing D. J. , Emmett B. A.
Published: July 2011

Abstract. Large areas of the United Kingdom currently have nitrogen (N) deposition at rates which exceed the thresholds above which there is risk of damage to sensitive components of the ecosystem (critical loads), and are predicted to continue to do so. Previous studies have shown that this excess N can be very damaging to semi-natural ecosystems. However, such studies have focussed primarily on the relationship of species richness to nitrogen, possibly missing the risk that increased deposition can have on individual plant species. To address this gap in knowledge, we used data from two national observation networks over Great Britain: the vascular plant database and the Botanical Society of the British Isles local change network to examine the response of individual vascular plant species to nitrogen in acid grasslands, calcareous grasslands and heathlands. Presence absence records of individual species, along with mean Ellenberg scores, within 10 km hectads were modelled against N deposition whilst at the same time controlling for the effects of climate, land use and sulphur deposition using generalised additive models. Ellenberg N showed a significant increase with increasing N deposition in almost all habitats across both surveys. Many individual species showed strong relationships with N deposition and clear negative trends in species prevalence to increasing nitrogen were found in all habitats. Species that showed negative relationships to N showed signs of decline at low levels, far below the current critical load levels.
Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr
Authors: Crosta X. , Romero O. E. , Ther O. , Schneider R. R.
Published: July 2011

Abstract. Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 12 000 calendar years (12 cal. ka BP) and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms to the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP. Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, which discharges were forced by precipitation over western Equatorial Africa. Precipitation in this region is controlled by the West African monsoon which is, in turn, dependent on the presence and intensity of the Atlantic Cold Tongue (ACT). The ACT was weakened and warmer, trade winds were less vigorous, could convection and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ~10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely, the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and since 5.5 cal. ka BP. Our results therefore give indication on the ocean and atmosphere dynamics over the last 40 000 yr.
Assessing water resources in China using PRECIS projections and VIC model
Authors: Wang G. Q. , Zhang J. Y. , Jin J. L. , Pagano T. C. , Calow R. , Bao Z. X. , S Liu C. , Liu Y. L. , Yan X. L.
Published: July 2011

Abstract. Climate change is now a major environmental and developmental issue, and one that will increase the challenge of sustainable water resources management. In order to assess the implications of climate change on water resources in China, a Variable Infiltration Capacity (VIC) model with a resolution of 50 × 50 km2 was calibrated using data from 125 well gauged catchments. According to similarities in climate conditions, soil texture and other variables, model parameters were transferred to other areas not covered by the calibrated catchments. Taking runoff in the period 1961 ~ 1990 as a baseline, the impact of climate change on runoff under three emissions scenarios of A2, B2 and A1B was studied. Model findings indicate that annual runoff over China as a whole will probably increase by approximately 3 ~ 10 % by 2050, but with quite uneven spatial and temporal distribution. The prevailing pattern of "north dry and south wet" in China is likely to be exacerbated under global warming.
Topographic Differences between Large and Normal Optic Discs: A Confocal Scanning Laser Ophthalmoscopy Study
Authors: Cankaya Ali Bulent , Simsek Tulay
Published: July 2011

Purpose

The aim of the study was to investigate the optic nerve head parameters of healthy macrodiscs to provide standard measurements for them to be the basis for future quantitative comparisons.

Methods

Sixty-nine subjects with macrodisc (disc area larger than 2.82 mm2) and 91 healthy controls (disc area between 1.16 and 2.82 mm2) were recruited. After a complete ophthalmic examination, confocal scanning laser ophthalmoscopy was performed in all participants. The stereometric parameters of confocal scanning laser ophthalmoscopy examination and the proportion of subjects classified as normal, borderline, and glaucomatous by the Moorfield Regression Analysis were compared between groups.

Results

A total of 160 subjects were included in the study. The average disc sizes in the control and macrodisc groups were 2.14±0.33 mm2 and 3.36±0.36 mm2, respectively. Cup area (p<0.001), rim area (p=0.01), cup volume (p<0.001), cup/disc area ratio (p<0.001), linear cup/disc ratio (p<0.001), mean cup depth (p<0.001), maximum cup depth (p<0.001), and cup shape measure (p<0.001) differed significantly between the 2 groups. The parameters of the optic nerve head which did not differ significantly between groups were rim volume (p=0.17) and height variation contour (p=0.88). A significantly higher number of eyes were erroneously identified as abnormal (15.1% vs 79.4%) by Moorfield Regression Analysis in the macrodisc group (p<0.001).

Conclusions

Rim volume and height variation contour were the only optic nerve head topographic parameters that were similar in eyes with large and normal disc sizes. They seem to be promising parameters in the evaluation and comparison of the optic nerve head of subjects with macrodisc.
Acute Posterior Shoulder Dislocation with Reverse Hill-Sachs Lesion of the Epiphyseal Humeral Head
Authors: Patrizio Luigi , Sabetta Ettore
Published: July 2011

Posterior dislocation of the shoulder is an unfrequent event that often occurs as a consequence of a direct trauma or epileptic crisis.
Frequently the posterior dislocations are misunderstood, so they become chronic lesions. We reported a case of an acute posterior left shoulder dislocation with lesser tuberosity fracture and reverse Hill-Sachs lesions which involved more than 25% of the articular surface of the humeral head, in a 57-old-year man with right hemiparesis.
We performed a synthesis of the lesser tuberosity with a screw, and we restored the shape of the humeral head with allograft. We achieved a good result that allows the patient to be able to do his previous activities of daily living.
Mammalian Cell Culture
Authors: Sandell Lisa , Sakai Daisuke
Published: July 2011

Mammalian cell culture is the process of growing animal cells in vitro in a flask or dish. This unit describes the methods, equipment, supplies, and reagents used in a cell culture laboratory. Because preventing contamination and maintaining purity of cell cultures is arguably the greatest challenge in animal cell culture, the principles of aseptic technique in mammalian cell culture are presented in detail. Cell culture media and additives are discussed. A method of counting cells and assessing their viability with a hemacytometer is illustrated. The steps needed to maintain an adherent cell line by feeding and passing cells from one culture vessel to another are presented and variations for passing suspension‐grown cells are also outlined. Long‐term cryogenic storage of cells in liquid nitrogen is discussed and a protocol for freezing cells is provided, as are details for thawing and recovering viable cells from frozen stocks. Curr. Protoc. Essential Lab. Tech. 5:4.3.1‐4.3.32. © 2011 by John Wiley & Sons, Inc.
Rising Masses, Singapore
Authors: Kahlen Max
Published: July 2011

Rising Masses, a year‐long final design thesis undertaken at the Architectural Association (AA) School of Architecture, is for a high‐rise building in the centre of Singapore's financial district. It is characterised by an extreme thinness that is intended to heighten the experience of working in such a dense urban context. As Max Kahlen of Dyvik & Kahlen, Architecture, explains, two mathematical‐based methods were employed in order to aid the design of such a thin structure. Copyright © 2011 John Wiley & Sons, Ltd.
Body fat is differentially related to body mass index in U.S.‐born African‐American and East African immigrant girls
Authors: Meyer Katie A. , Demerath Ellen W. , Friend Sarah , Hannan Peter J. , Neumark‐Sztainer Dianne
Published: July 2011

Objective:

To examine ethnic differences in adiposity at a given body mass index (BMI) in a sample of U.S.‐born African‐American and East African immigrant adolescent girls.

Methods:

In a sample of black adolescent girls (n = 79; ages 14–20) we compared measures of adiposity across the range of BMI‐for‐age among 55 U.S.‐born African‐American (mean BMI: 30.4; age: 15.4) and 24 East African immigrant girls (mean BMI: 21.8; age: 16.7). Fat and fat‐free mass were assessed with dual‐energy X‐ray absorptiometry (DXA). We used spline regression to examine the distributions of fat mass index and percent body fat across the range of BMI‐for‐age z‐scores.

Results:

Compared with African‐American girls, East African girls were smaller on all body measures, but appeared to have higher fat mass index and percent body fat at the same BMI‐for‐age.

Conclusions:

Our findings indicate that at a given BMI East African immigrants may have greater adiposity than African‐American girls. If corroborated in larger samples, our data suggest that the cardiometabolic risks attendant to elevated adiposity may affect East African girls at a lower BMI than in African‐American girls. Am. J. Hum. Biol., 2011. © 2011 Wiley‐Liss, Inc.
Studies on synthesis and physicochemical properties of new bis[4‐(2‐hydroxy‐3‐methacryloyloxypropoxy)phenyl]sulfide terpolymers
Authors: Podkościelna Beata , Maciejewska Małgorzata , Bartnicki Andrzej
Published: July 2011

Synthesis and physicochemical properties of the new glycidyl methacrylate, styrene, and bis[4(2‐hydroxy‐3‐methacryloyloxypropoxy)phenyl]sulfide terpolymers of different crosslinking degrees are presented. The terpolymers were obtained in the form of regular microspheres by suspension polymerization. The epoxy group content, thermal properties (DSC, thermogravimetric analysis), and swelling characteristic of the functional microspheres were examined. In addition, a selected terpolymer was modified in the epoxide ring opening reaction with diethylenetriamine. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Pharmacologic P2X purinergic receptor antagonism in the treatment of collagen‐induced arthritis
Authors: Ardissone Vittoria , Radaelli Enrico , Zaratin Paola , Ardizzone Michele , Ladel Christoph , Gattorno Marco , Martini Alberto , Grassi Fabio , Traggiai Elisabetta
Published: July 2011

Objective

To assess the therapeutic potential of a P2X purinergic receptor antagonist, namely, periodate oxidized ATP, in collagen‐induced arthritis (CIA).

Methods

Arthritis was induced in male DBA/1J mice by immunization with type II collagen (CII). Animals showing digit inflammation and paw swelling were treated intraperitoneally with 100 μl of 3 mM oxidized ATP daily for 10 days. At the end of the treatment period, animals were killed and paws were removed for histologic analysis and evaluation of T cell infiltration. Humoral response to CII was analyzed, and specific serum autoantibody levels were correlated with the clinical scores observed in the different treatment groups.

Results

Treatment with oxidized ATP resulted in a sustained reduction in disease activity, which was associated with a significant decrease in CD3+ T cell infiltration in arthritic lesions and a significant amelioration of cartilage erosion. Peripheral Treg cells were significantly increased upon P2X blockade in mouse lymph nodes. Moreover, a marked reduction in circulating autoantibodies directed against mouse CII was detected. There was a significant correlation between serum autoantibody levels and the clinical efficacy of oxidized ATP.

Conclusion

Our findings indicate that P2X receptor antagonism has important therapeutic potential in chronic inflammatory rheumatic disorders. Taken together, our results underscore the value of the P2X receptor signaling pathway as a potential pharmacologic target for the modulation of adaptive immunity in CIA.
Predictors of moderate‐to‐severe paravalvular aortic regurgitation immediately after corevalve implantation and the impact of postdilatation
Authors: Takagi Kensuke , Latib Azeem , Al‐Lamee Rasha , Mussardo Marco , Montorfano Matteo , Maisano Francesco , Godino Cosmo , Chieffo Alaide , Alfieri Ottavio , Colombo Antonio
Published: July 2011

Objective: To investigate the predictors of moderate‐to‐severe aortic regurgitation (AR≥2+) after CoreValve implantation and evaluate the feasibility and safety of postdilatation in reducing the degree of AR. Background: Although transcatheter aortic valve implantation is an alternative treatment for high surgical risk patients with severe aortic stenosis, post‐implantation paravalvular AR remains a complication. Methods: From July 2008 to July 2010, we enrolled 79 consecutive patients with severe aortic stenosis who underwent CoreValve implantation. Results: On univariable analysis, the predictors of AR≥2+ immediately after CoreValve implantation were: larger annulus size, low implantation, prosthesis mismatch, chronic renal insufficiency, a history of heart failure, and peripheral vascular disease. On multivariable analysis, the independent predictors of AR≥2+ were: larger annulus diameter (OR 1.78, 95%CI 1.25–2.55; P = 0.002), low implantation (OR 3.67, 95%CI 1.01–13.35, P = 0.05), and peripheral vascular disease (OR 3.54, 95%CI 1.19–10.56, P = 0.02). Post‐CoreValve implantation, AR ≥ 2 was seen in 40.5% (32/79). Twenty‐one patients underwent postdilatation with improvement in AR grade in the majority (17/21). Of the four patients who did not respond to postdilatation, two underwent valve‐in‐valve implantation. In one patient, the valve was pulled more proximally by the snare technique. The remaining 10 patients were treated conservatively. Conclusion: The appropriate strategy for treating patients with AR≥2+ depends on the causes and severity of AR post‐TAVI. This study suggests that we should carefully select the size of CoreValve prosthesis to prevent prosthesis mismatch, especially when implanted in larger annulus sizes. For valves implanted in the appropriate position, postdilatation appears effective in reducing the degree of AR. © 2011 Wiley‐Liss, Inc.
Multiplatform comparison of multiplexed bead arrays using HPV genotyping as a test case
Authors: Corrie Simon R. , Feng Qinghua , Blair Tiffany , Hawes Stephen E. , Kiviat Nancy B. , Trau Matt
Published: July 2011

While previous studies have investigated the utility of Luminex technology in comparison to other standard techniques, there have been few studies directly comparing different bead‐based assays. A key barrier to establishing Luminex technology in research or clinical laboratories is the apparent need to purchase not only encoded bead sets but also the Luminex instrument. However, as flow cytometry instrumentation continues to improve in sensitivity and in the number and diversity of detection parameters, a diverse range of bead‐based assays is likely to emerge. Human papillomavirus (HPV) genotyping requires multiplexed analysis of 10–100 individual genotypes per sample, which is well suited to bead‐based assays whilst technically challenging and costly for related technologies (e.g., qPCR). Here we performed an unbiased technical comparison between Luminex technology and our in‐house 3‐mercaptopropyl trimethoxysilane (“MPS”) bead platform, which has been designed for integration with generic cytometry instruments. In genotyping 200 clinical samples, we compared the two bead assays against the goldstandard Roche Line Blot (RLB) assay, and both performed well in receiver‐operator characteristic (ROC) curve analysis. We also show instrument‐based differences are a significant factor in comparing the methods, which needs to be considered in future comparative studies. These multi‐platform analyses are important in establishing the validity of new methods, as well as highlighting specific advantages anddisadvantages of the assays for specific applications. © 2011 International Society for Advancement of Cytometry
Oxidative stress in synapse development and function
Authors: Milton Valerie J. , Sweeney Sean T.
Published: July 2011

Oxidative stress, caused by increased levels of reactive oxidative species (ROS), is considered a major contributor to the aging process. How oxidative stress may bring about changes to structures and function in the aging brain is poorly understood. Oxidative stress activates a number of cellular responses, including activation of the Jun‐N‐terminal kinase (JNK) pathway and autophagy. In addition to their pathological role, ROS also act as signaling molecules. ROS such as nitric oxide have a well‐known role in learning and memory. In addition, activation of JNK and its transcriptional effector AP‐1 are well‐known mediators of synaptic function and growth. Both are essential mediators of physiological correlates of learning and memory such as long‐term potentiation. JNK and AP‐1 are potently activated and regulated by oxidative stress and mediate protective cellular responses such as autophagy. Recent work at the Drosophila neuromuscular junction implicates autophagy as a regulator of synaptic growth via activation of the JNK signaling pathway. We here outline a framework predicating oxidative stress as a major regulator of synaptic function and growth by the activation of JNK/AP‐1 and autophagy. Such responses, we suggest, may underpin some forms of synaptic growth responses and synaptic aging. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 72: 100–110, 2012
Small founding number and low genetic diversity in an introduced species exhibiting limited invasion success (speckled dace,Rhinichthys osculus)
Authors: Kinziger Andrew P. , Nakamoto Rodney J. , Anderson Eric C. , Harvey Bret C.
Published: July 2011

Molecular evaluations of successful invaders are common, however studies of introduced species that have had limited invasion success, or have died out completely, are rare. We studied an introduced population of speckled dace (Rhinichthys osculus) from northern California, USA that has rapidly increased in abundance but remained restricted to a 25‐km stretch of river since its introduction in the mid‐1980s. Field and laboratory analyses indicate that invasion success of speckled dace is constrained by the combined effects of multiple predators. The role of bottleneck effects associated with the introduction has not been studied. We assayed variation in seven microsatellite loci and one mitochondrial DNA gene in the introduced population and nine putative source populations to identify the source population and evaluate bottleneck effects. The Trinity River system was supported as the source owing to its genetic similarity and geographic proximity to the introduced population. Consistent with a bottleneck, the introduced population exhibited reduced allelic and haplotype richness in comparison to source populations. Estimates of the genetically effective number of individuals founding the introduced population using nuclear coalescent analyses and a mitochondrial simulation procedure were highly concordant in suggesting that the initial colonizing group was comprised of about 10 individuals. A bottleneck effect in an exotic species exhibiting limited invasion success has rarely been documented and thus introduction of speckled dace represents an important model system for future investigation. Establishing a relationship between genetic diversity and factors limiting invasion success in this system (e.g., predator avoidance) will help determine the extent to which genetic diversity loss has constrained invasion success in speckled dace.
(+)‐Flavipucine, the Missing Member of the Pyridione Epoxide Family of Fungal Antibiotics
Authors: Loesgen Sandra , Bruhn Torsten , Meindl Kathrin , Dix Ina , Schulz Barbara , Zeeck Axel , Bringmann Gerhard
Published: July 2011

From the culture extracts of the endophytic fungus, Phoma sp., isolated from the plant Salsola oppositifolia, five secondary metabolites were isolated and characterized. On biomalt agar medium, the strain produced the known substances chrysophanol (1) and hypothemycin (2), while from liquid‐surface fermentations on a glucose/maltose medium, 2,4‐pyridione derivatives were obtained. Interestingly, one of the isolated compounds, flavipucine (3a), showed a positive [α]D; it, thus, was the enantiomer of the known, but configurationally as yet unassigned (–)‐flavipucine (3b). By using quantum‐chemical circular‐dichroism calculations, the absolute configuration of 3a was established. Moreover, the dihydro analog 5 of flavipucine was isolated for the first time. The stereostructures were determined by extensive spectroscopic data analysis, quantum‐chemical circular dichroism calculations, and X‐ray analysis. With the two enantiomeric side‐chain analogues of flavipucine, fruit rot toxin A (FRT‐A) (6a) and the recently published sapinopyridione (6b), the family of four naturally occurring substituted 2,4‐pyridiones has become complete. Compound 3a exhibits antifungal activity against Phytophthora infestans and moderate inhibitory activity against gram‐positive and gram‐negative bacteria.
Performance analysis of a TH/DS N‐ary BPPM UWB system
Authors: Shen Ye‐Shun , Ueng Fang‐Biau
Published: July 2011

A hybrid time‐hopping/direct‐sequence (TH/DS) multiple access ultra‐wideband (UWB) system using N‐ary biorthogonal pulse position modulation (BPPM) is proposed and analysed in this paper. Based on the analytical characteristic function method, we derive the accurate probability distribution of the multiple access interference and calculate the average symbol error rate (SER) of the proposed system. Simulation results are provided to verify the analytical frameworks in additive white Gaussian noise channel and to illustrate the system performance in realistic UWB fading channels. The proposed TH/DS N‐ary BPPM system is shown to provide better SER performance compared with that of the conventional TH M‐ary PPM scheme. We also investigate the trade‐off of the proposed system parameters with fixed bit rate and fixed signal bandwidth. Copyright © 2011 John Wiley & Sons, Ltd.
Accurate particle splitting for smoothed particle hydrodynamics in shallow water with shock capturing
Authors: Vacondio R. , Rogers B. D. , Stansby P. K.
Published: July 2011

The solution for the shallow water equations using smoothed particle hydrodynamics is attractive, being a mesh‐free, automatically adaptive method without special treatment for wet–dry interfaces. However, the relatively new method is limited by the variable kernel size or smoothing length being inversely proportional to water depth causing poor resolution at small depths. Boundary conditions at solid walls have also not been well resolved. To solve the resolution problem in small depths, a particle splitting procedure was developed (conveniently into seven particles), which conserves mass and momentum by varying the smoothing length, velocity and acceleration of each refined particle. This improves predictions in the shallowest depths where the error associated with splitting is reduced by one order of magnitude in comparison to other published works. To provide good shock capturing behaviour, particle interactions are treated as a Riemann problem with Monotone Upstream‐centred Scheme for Conservation Laws (MUSCL) reconstruction providing stability. For solid boundaries, the recent modified virtual boundary particle method was developed further to enable the zeroth moment to be accurately conserved where the smoothing length of particles is changing rapidly during particle splitting. The resulting method is applied to the one‐dimensional and the two‐dimensional axisymmetric wet‐bed dam break problems showing close agreement with analytical solutions, demonstrating the need for particle splitting. To demonstrate wetting and drying in a more complex case, the scheme is applied to oscillating water in a two‐dimensional parabolic basin and produces good agreement with the analytical solution. The method is finally applied to the European Concerted Action on DAm break Modelling dam‐break test case representative of realistic conditions and good predictions are made of experimental measurements with a 40% reduction in the computational time when particle splitting is employed. The overall method has thus become quite sophisticated but its generality and versatility will be attractive for various shallow water problems. Copyright © 2011 John Wiley & Sons, Ltd.
Cancer surveillance in patients with primary sclerosing cholangitis
Authors: Razumilava Nataliya , Gores Gregory J. , Lindor Keith D.
Published: July 2011

Primary sclerosing cholangitis (PSC) is a chronic fibroinflammatory syndrome involving the biliary tract, often accompanied by inflammatory bowel disease (IBD). This syndrome is a prototype disease linking chronic inflammation to carcinogenesis. Indeed, PSC is associated with an increased risk of cholangiocarcinoma (CCA), gallbladder cancer, hepatocellular carcinoma (HCC), and colorectal cancer. Herein, we review the risk for these malignancies in PSC and discuss rational cancer surveillance strategies for these patients. Where evidence is limited, we suggest a pragmatic approach. In this regard, we recommend interval screening for CCA with noninvasive imaging modalities and serum carbohydrate antigen 19-9 determinations annually. These imaging studies also serve to screen for gallbladder cancer and HCC. Screening for colorectal cancer is more firmly established in PSC patients with IBD and includes colonoscopy at the time of PSC diagnosis and, thereafter, at 1-2-year intervals. We also highlight areas where more information is required, such as management of biliary tract dysplasia and cancer chemoprevention in PSC. (Hepatology 2011)