bluuebunny/crossref_metadata_2025 huggingface dataset:
Using mass spectrometry to detect buffalo salivary odorant‐binding protein and its post‐translational modifications
Authors: Rajkumar R. , Karthikeyan K. , Archunan G. , Huang P. H. , Chen Y. W. , Ng W. V. , Liao C. C.
Published: October 2010

A large number of mammalian odorant‐binding proteins, which are lipocalins, have been studied. These proteins participate in peri‐receptor events by selecting and carrying odorant molecules. The present study aimed at identifying the buffalo salivary odorant‐binding protein (sOBP), and to determine its post‐translational modification using mass spectrometry. The buffalo salivary 21 kDa protein was initially separated adopting sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and it was identified as sOBP with high statistical reliability using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and SEQUEST, for the first time. Further, the post‐translationally modified peptides were screened adopting MS/MS. A total of four post‐translational modifications, namely glycation at lysine‐59, hydroxylation at lysine‐134, ubiquitination at lysine‐121, and dihydroxylation in lysine‐108, were recorded. Moreover, these modifications have not been identified in buffalo salivary odorant‐binding protein. Copyright © 2010 John Wiley & Sons, Ltd.
College students' scientific epistemological views and thinking patterns in socioscientific decision making
Authors: Liu Shiang‐Yao , Lin Chuan‐Shun , Tsai Chin‐Chung
Published: October 2010

This study aims to test the nature of the assumption that there are relationships between scientific epistemological views (SEVs) and reasoning processes in socioscientific decision making. A mixed methodology that combines both qualitative and quantitative approaches of data collection and analysis was adopted not only to verify the assumption but also to explore the patterns of interaction between the two constructs. A total of 177 college students (60% science and 40% non‐science majors) completed a SEVs survey and a decision‐making instrument. The decision‐making instrument contains expository text introducing the environmental management issue of an invasive species, and a series of open‐ended questions to elicit participants' reasons and judgments on the issue. Analyses revealed that tentativeness and creativity of SEVs are the significant components directly manifested in the socioscientific decision‐making process. Students who held changing and tentative beliefs about scientific knowledge were more likely to recognize the complexity, take multiple perspectives, and question omniscient authority in the decision‐making process. It was also found that over one‐half of the college students, especially those who were science majors, make decisions based on a single disciplinary perspective. The findings suggest that educational programs should encourage students to actively participate in issue investigation and decision making by utilizing multiple reasoning modes and interdisciplinary thinking. © 2010 Wiley Periodicals, Inc. Sci Ed 95: 497–517, 2011
Compiler‐assisted dynamic scratch‐pad memory management with space overlapping for embedded systems
Authors: Yang Yanqin , Yan Haijin , Shao Zili , Guo Minyi
Published: October 2010

Scratch‐pad memory (SPM), a small, fast, software‐managed on‐chip SRAM (Static Random Access Memory) is widely used in embedded systems. With the ever‐widening performance gap between processors and main memory, it is very important to reduce the serious off‐chip memory access overheads caused by transferring data between SPM and off‐chip memory. In this paper, we propose a novel compiler‐assisted technique, ISOS (Iteration‐access‐pattern‐based Space Overlapping SPM management), for dynamic SPM management with DMA (Direct Memory Access). In ISOS, we combine both SPM and DMA for performance optimization by exploiting the chance to overlap SPM space so as to further utilize the limited SPM space and reduce the number of DMA operations. We implement our technique based on IMPACT and conduct experiments using a set of benchmarks from DSPstone and Mediabench on the cycle‐accurate VLIW simulator of Trimaran. The experimental results show that our technique achieves run‐time performance improvement compared with the previous work. The average improvements are 13.15, 19.05, and 25.52% when the SPM sizes are 1KB, 512 bytes, and 256 bytes, respectively. Copyright © 2010 John Wiley & Sons, Ltd.
Comparison of oscillation damping capability in three power control strategies for PMSG‐based WECS
Authors: Geng Hua , Xu David , Wu Bin , Yang Geng
Published: October 2010

With the aid of small signal analysis and digital simulations, this paper compares the mechanical and power oscillation damping performances of three power control strategies for the multi‐pole permanent magnetic synchronous generator (PMSG)‐based direct driven wind energy conversion system (WECS). Maximal power point tracking (MPPT) control implemented in the generator side has inherent abilities on the oscillation damping. For the smoothed or constant power requirements, power oscillations are hard to damp, and additional active damping controller is required. Active damping can be achieved with power control on the generator or grid side and DC link voltage control on the generator side. With additional compensator in the power or DC link voltage control loop, a damping torque is produced to suppress the oscillations. An improved control structure, which has inherent oscillation damping capability, is proposed for the power control of WECS. Combined with different power control strategies, this structure can be applied to achieve different power outputs. The validation of the proposed control structure is verified by the simulations. Copyright © 2010 John Wiley & Sons, Ltd.
Qualitative performance assessment of semiconductor switching device, converter and generator candidates for 10 MW offshore wind turbine generators
Authors: Badrzadeh Babak
Published: October 2010

This paper investigates the possibilities of viable power electronics converters, semiconductor switching devices and electric machines for 10 MW variable‐speed wind turbine generators. The maximum rated power of existing wind turbine configurations is in the range of 6 MW. The proposed alternatives are compared against several technical and economical factors, and their advantages over the present wind turbines are highlighted. A comprehensive performance comparison of modern power semiconductor devices, their electrical characteristics and the key differentiators among them are presented. The power electronics converters considered include all commercially available multilevel voltage source and current source converters as well as the opportunities offered by power electronics building block‐based design. The factors used for the comparison include the converter power range, capacitor voltage balancing, common mode voltage and current, electromagnetic interference emissions, fault ride‐through capability, reliability, footprint, harmonic performance, efficiency and losses, component count, risk of torsional vibration by the harmonics and inter‐harmonics, complexity, ease of back‐to‐back operation and filtering requirements. For the electric machines, this study concentrates on high‐temperature superconducting machines, multi‐phase induction machines and permanent magnet synchronous machines. These machines are compared against existing wind generator technologies in terms of their power range, torque density, efficiency, fault ride‐through capability, reliability, footprint, harmonic performance, ease of fault detection, excitation control, noise and vibration signature, oscillation damping, gearbox requirement, cost and the size of the associated converter. Copyright © 2010 John Wiley & Sons, Ltd.
Potential load reductions on megawatt turbines exposed to wakes using individual‐pitch wake compensator and trailing‐edge flaps
Authors: Markou Helen , Andersen Peter Bjørn , Larsen Gunner Chr.
Published: October 2010

Wind turbines located in wind farms experience inflow wind conditions that are substantially modified compared with the ambient wind field that applies for stand‐alone wind turbines because of upstream emitted wakes. This has implications not only for the power production of a wind farm, but also for the loading conditions of the individual turbines in the farm. The dynamic wake meandering model (DWM) is believed to capture the essential physics of the wake problem, and thus, both load and production aspects can be predicted, which is contrary to the traditional engineering wake prediction methods that typically focus on either load or power prediction. As a consequence, the wake affected inflow field generated by the DWM formulation opens for control strategies for the individual turbine. Two different control approaches for load reduction on the individual turbines are implemented in the multi‐body aero‐servo‐elastic tool HAWC2, developed at Risø‐DTU in Denmark, and their potential load reduction capabilities compared: (1) full‐blade ‘individual‐pitch controllers’ acting as wake compensators and (2) controllers using trailing‐edge flaps. Information on the wake inflow conditions, induced by upstream turbines, is extracted from measurements of the blade‐root bending moment and/or one‐point recordings of flow angle of attack to the blades (pitot tube) measurements. In the former implementation, the pitch angle of each blade is compensated for as an addition to the collective‐pitch, rotor‐speed control. In the latter implementation, the (uniform) flap deflection angle is dictated by the particular controller version in question. Copyright © 2010 John Wiley & Sons, Ltd.
Core Biopsy of the Breast Lesions: Review of Technical Problems and Solutions: A Pictorial Review
Authors: Park Jeong Mi , Yang Limin , Laroia Archana , Franken Edmund A. , Fajardo Laurie L.
Published: October 2010

Understanding and proper application of biopsy techniques are essential for patient care in imaging-guided breast intervention.
MDM2 promotes cell motility and invasiveness through a RING‐finger independent mechanism
Authors: Polański Radosław , Warburton Hazel E. , Ray-Sinha Arpita , Devling Timothy , Pakula Hubert , Rubbi Carlos P. , Vlatković Nikolina , Boyd Mark T.
Published: October 2010

Recent studies connect MDM2 with increased cell motility, invasion and/or metastasis proposing an MDM2‐mediated ubiquitylation‐dependent mechanism. Interestingly, in renal cell carcinoma (RCC) p53/MDM2 co‐expression is associated with reduced survival which is independently linked with metastasis. We therefore investigated whether expression of p53 and/or MDM2 promotes aggressive cell phenotypes. Our data demonstrate that MDM2 promotes increased motility and invasiveness in RCC cells (N.B. similar results are obtained in non‐RCC cells). This study shows for the first time both that endogenous MDM2 significantly contributes to cell motility and that this does not depend upon the MDM2 RING‐finger, i.e. is independent of ubiquitylation (and NEDDylation). Our data suggest that protein–protein interactions provide a likely mechanistic basis for MDM2‐promoted motility which may constitute future therapeutic targets.
Inhibition of the JNK/Bim pathway by Hsp70 prevents Bax activation in UV‐induced apoptosis
Authors: Li Hui , Liu Lei , Xing Da , Chen Wei R.
Published: October 2010

Here we studied the mechanism by which heat shock protein 70 (Hsp70) prevents Bax activation during ultraviolet (UV)‐induced apoptosis. UV treatment led to c‐Jun N‐terminal kinase (JNK) phosphorylation, Bim redistribution and subsequent Bax activation. Bim depletion caused a smaller reduction in apoptosis than that by JNK inhibition, indicating that Bim activation is not entirely responsible for induction of apoptosis and other mechanisms are involved. Hsp70 knockdown resulted in high levels of activated JNK and Bax, while Hsp70 overexpression inhibited these processes. These findings demonstrate that Hsp70 prevented Bax activation via inhibiting the JNK/Bim pathway. Simultaneously, increased binding of Hsp70 to Bax was observed. Collectively, our results for the first time demonstrate that Hsp70 prevents Bax activation both by inhibiting the JNK/Bim pathway and by interacting with Bax in UV‐induced apoptosis.
Risk Inequality and the Polarized American Electorate
Authors: Rehm Philipp
Published: October 2010

Why has the American political landscape grown more partisan since the 1970s? This article provides a novel account of the determinants of partisanship. The author argues that partisanship is not only shaped by the traditionally suggested socio-economic factors, but also by the uncertainty of future income (risk exposure): rich individuals facing a high degree of risk exposure (or poor people facing low risk exposure) are ‘cross-pressured’; while their income suggests that they should identify with the Republicans, their income prospects make them sympathize with the Democrats. These two traits have overlapped increasingly since the 1970s. Those with lower incomes tend to be also those with higher risk exposure (risk inequality increased). This has led to a sorting of the American electorate: more citizens have become ‘natural’ partisans.
Log canonical thresholds on Gorenstein canonical del Pezzo surfaces
Authors: Park Jihun , Won Joonyeong
Published: October 2010

We classify all the effective anticanonical divisors on weak del Pezzo surfaces. Through this classification we obtain the smallest number among the log canonical thresholds of effective anticanonical divisors on a given Gorenstein canonical del Pezzo surface.
Solutions of perturbed Schrödinger equations with electromagnetic fields and critical nonlinearity
Authors: Liang Sihua , Zhang Jihui
Published: October 2010

We consider the existence and multiplicity of standing-wave solutions

of nonlinear Schrödinger equations with electromagnetic fields and critical nonlinearity

Under suitable assumptions, we prove that it has at least one solution and that, for any m ∈ ℕ, it has at least m pairs of solutions.
Notes on contact Ricci solitons
Authors: Cho Jong Taek
Published: October 2010

A compact contact Ricci soliton (whose potential vector field is the Reeb vector field) is Sasaki–Einstein. A compact contact homogeneous manifold with a Ricci soliton is Sasaki–Einstein.
Follicular interactions affect the in vitro development of isolated goat preantral follicles
Authors: Duarte Ana Beatriz Graça , Chaves Roberta Nogueira , Araújo Valdevane Rocha , Celestino Juliana Jales , Silva Gerlane Modesto , Lopes Cláudio Afonso Pinho , Tavares Líliam Mara Trevisan , Campelo Cláudio Cabral , de Figueiredo José Ricardo
Published: October 2010

The aim of this study was to evaluate the influence of the number of follicles per drop (one or three) and antral follicles on in vitro development of isolated goat preantral follicles. Preantral follicles were isolated through microdissection and distributed individually (control) or in groups of three follicles (treatment) in microdroplets of α-MEM with or without 1000 ng/ml follicle stimulating hormone (FSH) for Experiments 1 and 2, respectively. Experiment 3 was divided into four treatments according to the presence of one or three preantral follicles, associated or not with antral follicles. After culture, oocytes were retrieved from morphologically normal follicles and submitted to in vitro maturation (IVM) and live/dead fluorescent labelling. Results of Experiment 1 (basic medium without FSH) showed that culture of preantral follicles in groups enhances viability, growth and antrum formation after 12 days. However, in the presence of FSH (Experiment 2), only the recovery rate of fully grown oocytes for IVM was significantly affected by grouping of follicles. In Experiment 3, in general, co-culture of preantral follicles with an early antral follicle had a detrimental effect on viability, antrum formation and production of oocytes for IVM. In conclusion, the performance of in vitro culture of goat preantral follicles is affected by the number of follicles per drop, the presence of an antral follicle and FSH.
Early presentation of endomyocardial fibrosis in a 22-month-old child: a case report
Authors: Cilliers Antoinette M. , Adams Paul E. , Mocumbi Ana O.
Published: October 2010

We present an unusual, biopsy-proven case of endomyocardial fibrosis in a 22-month-old male child, which progressed rapidly resulting in death. The patient was born to a father originating from Mozambique, where the disease is endemic but who had not himself travelled there, suggesting a genetic link. Other remarkable features were the presence of a right ventricular diverticulum, and a positive Mycoplasma pneumoniae immunoglobulin M enzyme-linked immunosorbent assay test.
Development of retrotransposon-based SSAP molecular marker system for study of genetic diversity in sea holly (Eryngium maritimum L.)
Authors: Ievina Baiba , Syed Naeem H. , Flavell Andrew J. , Ievinsh Gederts , Rostoks Nils
Published: October 2010

Eryngium maritimum L. is a wild plant species threatened or endangered in most of Northern Europe, where species is on the northern margin of its distribution range. Recent studies have found reduction of size and even extinction of many populations. Assessment of genetic diversity in natural populations of endangered wild plant species can reflect condition and fitness of particular population and inform decisions on appropriate conservation measures. Application of inter simple sequence repeat markers and chloroplast DNA sequencing could not resolve genetic relationship between E. maritimum populations in Northern Europe. Therefore, the more sensitive retrotransposon-sequence-specific amplification polymorphism (SSAP) molecular marker system was developed. Six Ty1-copia long terminal repeat retrotransposons were isolated from E. maritimum genome (Tem1–Tem6) and assessed for their utility as molecular markers in this species. Two retrotransposons – Tem2 and Tem5 – were recognized as most informative based on the level of polymorphism and SSAP banding pattern quality. On average, 20.4% of SSAP bands were polymorphic for the five most informative primer combinations in a set of 150 Northern European E. maritimum plants from 13 locations, providing a useful tool for assessment of genetic diversity in this endangered species.
Getting out what we put in: productivity of the English National Health Service
Authors: Castelli Adriana , Laudicella Mauro , Street Andrew , Ward Padraic
Published: October 2010

Many countries are incorporating direct measures of non-market outputs in the national accounts. For any particular output to be included there has to be data about it for two adjacent periods. This is problematic because the classification of non-market outputs is often subject to wholesale revision. We outline the challenges associated with classification changes and propose a solution. To illustrate we construct output and input indices and estimate productivity growth of the English National Health Service (NHS) for the period 2003–2004 to 2007–2008. Our index of output growth incorporates all care provided to NHS patients and captures improvements in survival rates, waiting times and disease management. We find that more patients are being treated and the quality of the care they receive has been improving. We implement our approach to dealing with changes as to how health services are defined and show what effect this has on estimates of output growth. Our index of input growth captures all labour, intermediate and capital inputs into health service production and we improve on how capital has been measured in the past. Inputs have increased over time but there has also been a slowdown since 2005–2006, primarily the result of a levelling off in staff recruitment and less reliance on the use of agency staff. Productivity is assessed by comparing output growth with growth in inputs, the net effect being constant productivity growth between 2003–2004 and 2007–2008.
Definitional Challenges of Dealing with Sovereign Wealth Funds
Authors: ROZANOV Andrew
Published: October 2010

International policy-makers so far have successfully pre-empted any new major national legislation in the G7 countries aimed specifically at sovereign wealth funds by getting the International Monetary Fund to work with them on formulating a set of best practices commonly known as the Santiago Principles. However, some observers stress that this is just the beginning. How does one measure and evaluate compliance with these principles? Is voluntary self-regulation really sufficient? Or is there a need for new rules and regulations? As the discussion shifts from policy and economics to governance and regulation, we move firmly into the realm of law—legal norms, rules, and statutes. However, the required clarity and commonality of definitions and terms have been elusive. There does not seem to be universal agreement about the precise meanings of even the most fundamental terms in the SWF debate. This article hence focuses on the definitional challenges inherent in this debate.
Modeling regional to global CH4 emissions of boreal and arctic wetlands
Authors: Petrescu A. M. R. , van Beek L. P. H. , van Huissteden J. , Prigent C. , Sachs T. , Corradi C. A. R. , Parmentier F. J. W. , Dolman A. J.
Published: October 2010

Methane (CH4) emission from boreal, arctic and subarctic wetlands constitutes a potentially positive feedback to global climate warming. Many process‐based models have been developed, but high uncertainties remain in estimating the amount of CH4 released from wetlands at the global scale. This study tries to improve estimates of CH4 emissions by up‐scaling a wetland CH4 emission model, PEATLAND‐VU, to the global scale with a spatial resolution of 0.5° for the period 2001–2006. This up‐scaling was based on the global circum‐arctic distribution of wetlands with hydrological conditions being specified by a global hydrological model, PCR‐GLOBWB. In addition to the daily hydrological output from PCR‐GLOBWB, comprising water table depths and snow thickness, the parameterization included air temperature as obtained from the ECMWF Operational Archive. To establish the uncertainty in the representations of the circum‐arctic distribution of wetlands on the CH4 emission, several existing products were used to aggregate the emissions. Using the description of potential peatlands from the FAO Digital Soil Map of the World and the representation of floodplains by PCR‐GLOBWB, the average annual flux over the period 2001–2006 was estimated to be 78 Tg yr−1. In comparison, the six‐year average CH4 fluxes were 37.7, 89.4, 145.6, and 157.3 Tg yr−1 for different estimates of wetland extends based on the studies by Matthews and Fung, Prigent et al., Lehner and Döll, and Kaplan, respectively. This study shows the feasibility to estimate interannual variations in CH4 emissions by coupling hydrological and CH4 emission process models. It highlights the importance of an adequate understanding of hydrology in quantifying the total emissions from northern hemispheric wetlands and shows how knowledge of the sub‐grid variability in wetland extent helps to prescribe relevant hydrological conditions to the emission model as well as to identify the uncertainty associated with existing wetland distributions.
Extreme value statistics in the solar wind: An application to correlated Lévy processes
Authors: Moloney Nicholas R. , Davidsen Jörn
Published: October 2010

The interplay between the solar wind and the Earth's magnetosphere is a longstanding and challenging problem. An estimate of the energy influx into the magnetosphere is given by the Akasofu ε parameter. Extreme values of this parameter are of interest not only for magnetospheric response but also for the design of satellites, space stations, and considerations of astronaut safety. For the ε time series derived from ACE spacecraft measurements for the years 2000–2007, we find that its distribution of extreme values over time windows of about 18 h and longer can be accurately described by parametric models based on the mathematical theory of generalized extreme value statistics. These models predict that significantly larger values than observed to date can be expected during any 50 year period. While our findings seem to suggest that correlations and/or nonstationarities do not play a significant role for the extreme value statistics of the Akasofu ε parameter, we show that the contrary is in fact true. To isolate the effect of correlations and finite observation periods, we also consider the distribution of maximal changes in the ε parameter and compare it to the extreme value statistics of a recently proposed fractional Lévy motion‐type model. However, we find that fractional Lévy motion does not reliably capture the extremal behavior of the ε time series.
Enceladus plume variability and the neutral gas densities in Saturn's magnetosphere
Authors: Smith H. T. , Johnson R. E. , Perry M. E. , Mitchell D. G. , McNutt R. L. , Young D. T.
Published: October 2010

Neutral particle dominance over charged particles in Saturn's magnetosphere was evident prior to Cassini's arrival at Saturn in 2004. The observation of active plumes emanating from the south pole of Enceladus suggests that this small moon is likely to be the principal source of neutrals in Saturn's magnetosphere. Cassini has flown through the plumes on several occasions, and the resulting data imply the source rate is variable (∼1027 to 1028 water molecules/s). Here we use Cassini plasma spectrometer and Cassini magnetospheric imaging instrument observations to update neutral particle lifetimes and then use the most recent processed versions of Cassini ion neutral mass spectrometer observations made during encounters E2, E3, and E5 to constrain a 3‐D multispecies neutral particle model. This procedure improves constraints on the plume source rate, ejection velocity, and plume divergence. We find that the plume source rate varies by at least a factor of 4 over the 7 month period considered. Additionally, we find that previous estimates of the plume source rates based on E2 observations are most likely overestimated because the background neutral torus has not been adequately account for. On the basis of these results, we discuss the implications of this variability on global neutral particle distributions.
The long runout of the Heart Mountain landslide: Heating, pressurization, and carbonate decomposition
Authors: Goren L. , Aharonov E. , Anders M. H.
Published: October 2010

The Heart Mountain landslide of northwestern Wyoming is the largest subaerial landslide known. This Eocene age slide slid ∼50 km along a shallow 2° slope, posing a long‐standing enigma regarding its emplacement mechanism. We suggest here a mechanism for the catastrophic emplacement of the Heart Mountain landslide that is independent of slide triggering. The mechanism is a feedback between shear heating, thermal pressurization, and thermal decomposition of carbonates at the slide shear zone. Such a feedback arises when a porous, fluid‐filled shear zone heats up because of frictional sliding. If the shear zone is confined, the generated heat leads to pore pressure rise, which in turn reduces frictional resistance to sliding, leading to acceleration. Temperatures at the shear zone quickly reach the decomposition temperature of carbonates. Since the shear zone of the Heart Mountain slide is located within a dolomite layer, it is expected that thermal decomposition of dolomite occurred within the Heart Mountain shear zone. This prediction is supported by ample field evidence for carbonate decomposition during the emplacement. Simulation of the sliding dynamics of the Heart Mountain block, accounting for feedback between shear heating, thermal pressurization, and thermal decomposition of carbonates, successfully reproduce the travel distance of the Heart Mountain block. The simulation results also predict that the maximum sliding velocity ranged between tens of meters per second to more than 100 m s−1 (depending on model assumptions) and that the duration of sliding was of the order of a few tens of minutes, in agreement with previous assessments.
East‐west asymmetry in nonlinear internal waves from Luzon Strait
Authors: Buijsman M. C. , McWilliams J. C. , Jackson C. R.
Published: October 2010

The nonhydrostatic Regional Ocean Modeling System is applied to study the effects of thermocline shoaling/deepening, bathymetry, and asymmetric modulated tides on the soliton growth to the west and east of Luzon Strait in the South China Sea and western Pacific Ocean. Luzon Strait comprises a shallow east ridge and a deep west ridge, and its interaction with barotropic tidal currents yields strong westward internal tides that disperse into solitons. Satellite imagery indicates that the westward solitons are more numerous and better defined than the eastward solitons. The model results show that the eastward solitons are 45%, 39%, 28%, and 23% smaller than the westward solitons due to asymmetric modulated barotropic tides at the east ridge, a deeper Pacific Ocean, westward thermocline shoaling related to the Kuroshio current, and internal tide resonance in a double ridge configuration, respectively. Due to the westward location of the Kuroshio, little thermocline deepening occurs east of the east ridge. Hence, the influence of thermocline deepening on counteracting eastward soliton growth is small. The Kuroshio mainly enhances westward soliton growth. The dispersion of internal tides into solitons is governed by the balance between the nonlinearity parameter on the one hand and the nonhydrostatic and Coriolis dispersions on the other. It is shown that this balance favors soliton growth for thermocline shoaling, while it counters it for a deeper ocean. A series of double ridge experiments is performed, in which the distance between the ridges and the height of the west ridge are varied. For a semidiurnal tidal forcing and two Gaussian ridges separated by 100 km, barotropic to baroclinic energy conversion is enhanced at both ridges, causing larger westward internal tides and solitons. The combination of Coriolis forcing, thermocline shoaling, and a double ridge configuration enhances the distinctiveness of the so‐called type a and b solitons when a modulated tide occurs.
Characterizing the retrieval of cloud properties from optical remote sensing
Authors: Vukicevic Tomislava , Coddington Odele , Pilewskie Peter
Published: October 2010

This paper presents a new approach to the formal characterization of the optical retrieval of cloud optical thickness and effective droplet radius based on a nonlinear methodology that is derived from a general stochastic inverse problem formulation similar to standard Bayesian estimation theory. The methodology includes efficient use of the precomputed radiative transfer model simulations which are already available in standard retrieval algorithms. Another important property of the methodology is that it does not require performing the retrieval with actual measurements in order to characterize the retrieval results. One utility of this analysis is the quantification of information content in the standard retrieval problem, and the increase of information through adding channels (radiances at different wavelengths) to the inversion. This was demonstrated for the five‐wavelength retrieval using airborne hyperspectral shortwave irradiance measurements. The ability of the method to evaluate the impact of observation and radiative transfer model uncertainties on the retrieved cloud properties is also demonstrated. Further benefits from this study will be in its application to the cloud retrieval algorithms to be developed for future space‐ and airborne instruments. The present study puts forth the framework necessary to quantify that increase in information and to optimize new retrieval algorithms that efficiently accommodate the enhanced measurement space.
Using MODIS EVI to detect vegetation damage caused by the 2008 ice and snow storms in south China
Authors: Chen Ji , Sun Liqun
Published: October 2010

This study develops a new method for detecting areas with severe vegetation damage caused by a serious ice and snow storm event that occurred in southern China over the period of 10 January to 2 February 2008. The new method adopts one of the Moderate Resolution Imaging Spectroradiometer (MODIS) MOD13A1 products, the enhanced vegetation index (EVI). Using a series of 16 day EVI maps at the 500 m spatial resolution in the 2008 growing season, the vegetation damage due to the event could be observed at a great number of patches, most of which are located outside of the regions with a flat topography. From a comparison of the MODIS Leaf Area Index (LAI), the Land Surface Temperature (LST) products, and the Landsat images obtained before and after the event, the severe vegetation damage is substantiated by a decreasing LAI, an increasing LST, and the “browning” of green vegetation in these patches. The analysis of topographic features discloses that the locations with the severe vegetation damage are mainly on slopes with easterly, southerly, and southeasterly aspects and in the moderate elevation region of between 500 and 700 m. During the event period, most of the patches that exhibited vegetation damage had a minimum temperature slightly above 0°C, experienced a minimum relative humidity of more than 75%, and accumulated a precipitation depth of more than 130 mm.
Pore fluid chemistry of the North Anatolian Fault Zone in the Sea of Marmara: A diversity of sources and processes
Authors: Tryon M. D. , Henry P. , Çağatay M. N. , Zitter T. A. C. , Géli L. , Gasperini L. , Burnard P. , Bourlange S. , Grall C.
Published: October 2010

As part of the 2007 Marnaut cruise in the Sea of Marmara, an investigation of the pore fluid chemistry of sites along the Main Marmara Fault zone was conducted. The goal was to define the spatial relationship between active faults and fluid outlets and to determine the sources and evolution of the fluids. Sites included basin bounding transtensional faults and strike‐slip faults cutting through the topographic highs. The basin pore fluids are dominated by simple mixing of bottom water with a brackish, low‐density Pleistocene Lake Marmara end‐member that is advecting buoyantly and/or diffusing from a relatively shallow depth. This mix is overprinted by shallow redox reactions and carbonate precipitation. The ridge sites are more complex with evidence for deep‐sourced fluids including thermogenic gas and evidence for both silicate and carbonate diagenetic processes. One site on the Western High displayed two mound structures that appear to be chemoherms atop a deep‐seated fluid conduit. The fluids being expelled are brines of up to twice seawater salinity with an exotic fluid chemistry extremely high in Li, Sr, and Ba. Oil globules were observed both at the surface and in cores, and type II gas hydrates of thermogenic origin were recovered. Hydrate formation near the seafloor contributes to increase brine concentration but cannot explain their chemical composition, which appears to be influenced by diagenetic reactions at temperatures of 75°C–150°C. Hence, a potential source for fluids at this site is the water associated with the reservoir from which the gas and oil is seeping, which has been shown to be related to the Thrace Basin hydrocarbon system. Our work shows that submerged continental transform plate boundaries can be hydrologically active and exhibit a diversity of sources and processes.
Mesospheric implications for the reaction of Si+ with O2(a1Δg)
Authors: Eyet Nicole , Bemish Raymond J. , Viggiano A. A. , Plane John M. C.
Published: October 2010

The rate constant for the reaction of Si+ with O2(a 1Δg) was measured in a selected ion flow tube (SIFT) between 200 and 500 K. The temperature dependence is T−(2.2±0.8). The rate constant at 500 K is below the detection limit (<1 × 10−11 cm3 molecule−1 s−1) while the rate constant at 200 K is 3.6 × 10−11 cm3 molecule−1 s−1. The product is SiO+, in accord with potential energy surfaces. These surfaces also show that the reaction of Si+ with O2(3Σg−) only yields association products, SiOO+ or OSiO+ ions. An upper mesosphere/lower thermosphere model predicts that reaction with O2(a 1Δg) is the most important removal process for Si+ during the day between 87 and 107 km, which may explain the depletion of this ion relative to other ions of meteoric origin, such as Fe+ and Mg+. The reaction therefore has an important influence on the composition and lifetimes of sporadic E layers during daytime.
Evaporation Change and Global Warming: The Role of Net Radiation and Relative Humidity
Authors: Lorenz David J. , DeWeaver Eric T. , Vimont Daniel J.
Published: October 2010

The change in evaporation over the oceans in climate models is analyzed from the perspective of air‐sea turbulent fluxes of water and energy. The results challenge the view that the change in evaporation is predominantly constrained by the change in the net radiation at the surface. For fixed net radiation change, it is found that (1) robust increases in near‐surface relative humidity and (2) robust decreases in turbulent exchange coefficient lead to a substantial reduction in evaporation below the rate of increase implied by the net radiation alone. This reduction of evaporation is associated with corresponding changes in the sensible heat flux. In addition, a net imbalance in the surface energy budget under transient greenhouse gas forcing provides a further reduction in the evaporation change in climate models. Further results also suggest that it might be more physical to view the evaporation change as a function of relative humidity change rather than net radiation. In this view, the relative humidity controls the net surface shortwave radiation through changes in low‐level cloudiness and the temperature controls the net surface radiation through the changes in longwave radiation. In addition, the results demonstrate the dominant role of both the air‐sea temperature difference and relative humidity over, for example, wind speed in reducing the evaporation change in climate models below the Clausius‐Clapeyron rate.
Relations between geological characteristics and satellite‐derived infrared and microwave emissivities over deserts in northern Africa and the Arabian Peninsula
Authors: Jiménez Carlos , Catherinot Julie , Prigent Catherine , Roger Jack
Published: October 2010

Infrared and microwave emissivities have been previously calculated over the globe from satellite observations to estimate the longwave radiative budget of the planet in global circulation models (GCM) or to facilitate the assimilation of surface‐sensitive satellite observations over land in numerical weather prediction (NWP) models. This study examines the relationship between these emissivities and the soil lithology over the deserts in northern Africa and the Arabian Peninsula at large scales. For this purpose, a lithology map of the area has been carefully derived from combining several geological maps and in situ lithostratigraphic columns. Infrared and microwave emissivities show large spatial variability, much more than often assumed in GCM or in NWP models, that relate well to the surface properties, especially the lithology. Changes in the lithology explain ∼40% and up to 50% of the emissivities variability at the considered frequencies in the infrared and in the microwaves. In particular, siliceous and carbonate outcrops have specific signatures that can be identify in these wavelength ranges, with a surprisingly good sensitivity of the microwaves to the presence of carbonates. This study clearly indicates that geological information is necessary for emissivity modeling, not only in the infrared but also in the microwaves, for GCM and NWP applications. The lithology maps created from the geological maps for this study is available under request. Our study also suggests that the combination of infrared and microwave emissivities has some potential for lithology mapping at large scales, especially for land surface models.
Infrasound observations of the 2008 explosive eruptions of Okmok and Kasatochi volcanoes, Alaska
Authors: Arnoult Kenneth M. , Olson John V. , Szuberla Curt A. L. , McNutt Stephen R. , Garcés Milton A. , Fee David , Hedlin Michael A. H.
Published: October 2010

The recent explosive eruptions of Okmok and Kasatochi volcanoes provide an opportunity to use seismic, local infrasound, distant infrasound array, and remote sensing data in concert to better monitor volcanoes in the Aleutian Arc and to better understand the source processes. The eruption of Okmok Volcano began on 12 July 2008 and included a seismically active phase that lasted continuously for about 10 h. In contrast, the eruption of Kasatochi which began on 7 August 2008 consisted of five explosive events that lasted from 26 to 68 min each and had a cumulative duration of 3.4 h. Given the event times by local seismic stations, the corresponding infrasound signals were found in the data recorded by local infrasound sensors and by distant infrasound arrays. Signals from the Okmok eruption were detected by three International Monitoring System (IMS) arrays as far away as 4400 km; signals from the Kasatochi eruption were detected at greater distances up to 5200 km away by seven infrasound arrays including the ones that detected the event at Okmok Volcano. Back azimuth propagation and a simple acoustic wave propagation model in unison with known event times were used to confirm that the planar, acoustic signals recorded at the arrays had originated from the eruptions. The infrasound array data reflected the differences in eruption styles between Okmok and Kasatochi as the signals from Kasatochi were of shorter duration, of greater amplitude, and detected over greater distances. The infrasound array data were also able to distinguish between two types of tremor episodes that occurred at Kasatochi Volcano based on atmospheric disturbance.
A comparative study of nucleation parameterizations: 1. Examination and evaluation of the formulations
Authors: Zhang Yang , McMurry Peter H. , Yu Fangqun , Jacobson Mark Z.
Published: October 2010

Large uncertainty exists in the nucleation parameterizations that may be propagated into climate change predictions through affecting aerosol direct and indirect effects. These parameterizations are derived either empirically from laboratory/field measurements or from theoretical models for nucleation rates. A total of 12 nucleation parameterizations (7 binary, 3 ternary, and 2 power laws) that are currently used in three‐dimensional air quality models are examined comparatively under a variety of atmospheric conditions from polluted surface to very clean mesosphere environments and evaluated using observations from several laboratory experiments and a field campaign conducted in a sulfate‐rich urban environment in the southeastern United States (i.e., Atlanta, Georgia). Significant differences (by up to 18 orders of magnitude) are found among the nucleation rates calculated with different parameterizations under the same meteorological and chemical conditions. All parameterizations give nucleation rates that increase with the number concentrations of sulfuric acid but differ in terms of the magnitude of such increases. Differences exist in their dependencies on temperatures, relative humidity, and the mixing ratios of ammonia in terms of both trends and magnitudes. Among the 12 parameterizations tested, the parameterizations of Kuang et al. (2008), Sihto et al. (2006), and Harrington and Kreidenweis (1998) give the best agreement with the observed nucleation rates in most laboratory studies and in Atlanta during a summer season field campaign and either do not exceed or rarely exceed the upper limits of the nucleation rates (i.e., the dimer formation rate) and new particle formation rates (i.e., the formation rate of particles with 2 nm diameter). They are thus the most plausible nucleation parameterizations for applications in the planetary boundary layer of polluted sulfate‐rich urban areas. Limitation with the two power laws are that they were derived empirically based on observations at specific locations under certain atmospheric conditions that may be different from laboratory measurement conditions and those at other locations and that they do not consider RH and T dependence. By contrast, the ternary nucleation parameterization of Napari et al. (2002) should not be used because it grossly overpredicts the observed nucleation rates, often exceeding the upper limit dimer or new particle formation rates, and giving an enhancement factor due to the presence of ammonia and a dependence on relative humidity that are inconsistent with laboratory measurements. The binary nucleation parameterization of Wexler et al. (1994) and Kulmala et al. (1998b) also should not be used because the former gives nucleation rates exceeding the upper limits under most atmospheric conditions and the latter contains technical mistakes in its formula.
Midlatitude cirrus cloud radiative forcing over China
Authors: Min Min , Wang Pucai , Campbell James R. , Zong Xuemei , Li Ying
Published: October 2010

Midlatitude cirrus cloud radiative forcing (CRF) values at the tropopause over China are estimated using a radiative transfer model initialized by Earth‐orbiting Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) and Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. A derived diurnal mean CRF, solved as a function of solar zenith angle, θ, though varied over the solar day, is used to evaluate the sensitivity and influence of θ on CRF calculations. Although a total mean net (NET) CRF of 36.5 ± 48.4 W m−2, estimated using direct observation data, is approximately equal to the value of 36.8 ± 50.4 W m−2 from the diurnal mean simulations, monthly differences illustrate a seasonality function dictating the influence of θ on CRF. A significant positive NET effect exceeding ∼ 80 W m−2 over the Qinghai‐Tibet Plateau is found, which is in contrast to a NET CRF found to be closer to 20 W m−2 for most parts of China. This finding is attributable to a more prominent warming effect of cirrus clouds observed over higher terrain. Furthermore, a warmer and more humid thermal profile over the high terrain in summer induces decreases in longwave (LW) and NET CRF over the plateau. The seasonal spatial variability of cirrus cloud visible optical depths also contributes to the corresponding spatial variability of shortwave (SW), LW, and NET CRF solved.
Spatial organization of intestinal microbiota in the mouse ascending colon
Authors: Nava Gerardo M , Friedrichsen Hans J , Stappenbeck Thaddeus S
Published: October 2010

Complex microbial populations are organized in relation to their environment. In the intestine, the inner lining (mucosa) is a potential focal point for such organization. The proximal murine colon contains mucosal folds that are known to be associated with morphologically distinct microbes. To identify these microbes, we used the technique of laser capture microdissection (LCM) to sample microbes associated with these folds (interfold region) and within the central lumen (digesta region). Using 16S rRNA gene tag pyrosequencing, we found that microbes in the interfold region were highly enriched for the phylum Firmicutes and, more specifically, for the families Lachnospiraceae and Ruminococcaceae. Other families such as Bacteroidaceae, Enterococcaceae and Lactobacillaceae were all enriched in the digesta region. This high-resolution system to capture and examine spatial organization of intestinal microbes should facilitate microbial analysis in other mouse models, furthering our understanding of host–microbial interactions.