bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Throughput Measurement of 41Ca by Accelerator Mass Spectrometry to Quantitate Small Changes in Individual Human Bone Turnover Rates
Authors: Hillegonds Darren J. , Fitzgerald Robert , Herold David , Lin Yumei , Vogel John S.
Published: June 2004

Biochemical markers of bone turnover suffer from large analytical and natural fluctuations (20-30%), making small differences in bone resorption impossible to resolve. This limits the clinical utility of such markers for individuals with the skeletal complications associated with many disease states (e.g., metastatic cancer, renal failure, osteoporosis). We are developing the capability to measure small changes (5-10%) in bone turnover rate in vivo by tagging the living skeleton with 41Ca. Among the stable and radioactive calcium isotopes, only 41Ca is useful for direct quantitation of bone turnover because it is extremely rare in nature and radiologically benign (105 years half-life, pure electron capture decay). The ratio of this tracer to total calcium remains quantifiable in body fluids and excreta via accelerator mass spectrometry (AMS) for many years following a single physiological-sized oral or intravenous dose. The highly automated AMS instrumentation and streamlined sample preparation allows a single operator to prepare or run more than 100 samples per day—significantly more than other 41Ca programs worldwide. We intend to exploit these measurements for earlier diagnosis of pathological processes and interactive intervention with therapeutic agents, allowing modulation of these agents to obtain the best individual result for a patient.
Micro Parallel Liquid Chromatography for High-Throughput Compound Purity Analysis and Early ADMET Profiling
Authors: Patel Paren , Osechinskiy Sergey , Koehler Jeff , Zhang Li , Vajjhala Surekha , Philips Chris , Hobbs Steve
Published: June 2004

The Nanostream (Pasadena, CA) Veloce system, together with 24-column Brio cartridges, offers a novel approach to micro parallel liquid chromatography (μPLC). This system allows users to achieve unprecedented throughput for standard assays while matching the performance of conventional LC instrumentation, thus enabling routine compound purity assessment and physiochemical property profiling early in the drug discovery and development process.

The Veloce system—which includes instrumentation, software, and replaceable microfluidic cartridges—incorporates pressure-driven flow to achieve chromatograms comparable to conventional high performance liquid chromatography (HPLC) instrumentation for a broad class of analytical applications while offering a dramatic increase in sample analysis capacity. The system enables parallel chromatographic separations and simultaneous, real-time UV detection. Each Nanostream Brio cartridge, made of polymeric materials, incorporates 24 columns packed with standard (C-18) stationary phase material to achieve reverse phase separations. Mixing and distribution of the mobile phase to each of the 24 columns is precisely controlled in each cartridge. The system provides an ideal platform to accelerate assessment of compound purity and physicochemical properties (i.e., log P, CHI, etc.) for a large number of compounds. In addition, the 24-fold increase in sample analysis capacity allows standard curve generation and simultaneous analysis of multiple replicates of samples in a single run. (JALA 2004;9:185-91)
Theory, technology and the music curriculum
Authors: Cain Tim
Published: June 2004

In this short article I present a case for developing a new theory of music education, arguing that advances in music technology have undermined some of the most basic conceptual frameworks we currently possess. I describe some problems that might make the development of a new theory difficult and suggest some ways in which they might be overcome. My hope is that this paper will inspire people to consider the development of such a theory.
Attitudes towards information technology in music learning among Hong Kong Chinese boys and girls
Authors: Ho Wai-Chung
Published: June 2004

This article argues that changes of gendered attitudes towards IT among students may be related to recent educational reforms focusing on incorporating computers into the classroom. Data are drawn from an interview survey with 430 students attending 26 primary and secondary schools in Hong Kong. The results reveal no significant differences between females and males in three aspects: (1) their belief in the effectiveness of using technological facilities; (2) their confidence in handling technology when learning about music; and (3) their motivation towards learning about music with the help of information technology (IT). Primary boys and girls in this study reported obtaining a higher degree of motivation for learning about music with the help of IT than secondary students of both sexes. The potential implications of these findings for educational policy in Hong Kong are to find out how to motivate students' musical learning with the help of IT, and to make technology relevant to the content of the music programmes of primary and secondary schools.
Embodiment in musical knowing: how body movement facilitates learning within Dalcroze Eurhythmics
Authors: Juntunen Marja-Leena , Hyvönen Leena
Published: June 2004

This paper examines how body movement within the frames of Dalcroze Eurhythmics can facilitate musical knowing. Merleau-Ponty's philosophical ideas seem to correspond with the specific empirical findings of Jaques-Dalcroze. Hence, our viewpoint is based on Merleau-Ponty's notions of ‘knowing the world through the body’ as well as of gesture, habit and reversibility. We argue, along with Merleau-Ponty, that the body is our primary mode of knowing. Furthermore, we suggest that body movement represents pre-reflective knowing and can be understood as physical metaphor in the process of musical understanding from the concrete doing/musicing to the abstract and (or) conceptual.
Working in music: the conservatoire professor
Authors: Mills Janet
Published: June 2004

This article describes an innovative approach to analysing, describing and evaluating the careers of musicians, and applies it in the case of 37 ‘professors’, that is, instrumental teachers, working at a conservatoire in the UK. The professors emerge as flexible and committed musicians who enjoy teaching conservatoire students, and who nearly all feel that they benefit musically and personally from this work.
A case of cyclogenesis over the western Mediterranean Sea with extraordinary convective activity
Authors: Kurz M. , Fontana A. Dalla
Published: June 2004

An interesting case of cyclogenesis over the western Mediterranean Sea, accompanied by extraordinary convective activity, is described in this paper. The event took place between 18 and 21 July 2001. Its synoptic features are examined on the basis of quasi‐geostrophic theory using numerical analyses from the global model of Deutscher Wetterdienst GME and from the ECMWF. Particularly remarkable is the large amount of latent heat released in the condensation process, which produces significant modifications of the flow. These effects are evident both in the fields of relative vorticity as well as potential vorticity in the upper levels. The infrared Meteosat satellite pictures are used to follow the evolution of the upper‐level cloudiness associated with the process and its connection with the values of vorticity and winds at 300 hPa. Radar pictures, reflectivity and radial velocity from Doppler surveillance radar in the Veneto region allowed us to outline the structure of the mesoscale convective system –a squall line that developed during the night of 19–20 July over Italy, in the Padana Valley. The features of this system were compared with a conceptual model proposed by Houze et al. (1989). The vertical wind shear, as inferred from the radial velocity pictures, was likely to play an important role in the development of the storm. Finally, an analysis of the vertical stability in the pre‐storm environment was performed using sounding data from Udine, 20 July 2001, 00 UTC. The analysis shows the importance in the storm development of the potential instability released by ascent during the transit of the baroclinic system, a process that was investigated using the vertical profile of equivalent potential temperature and an estimate of ascending motion given by the ECMWF model. Copyright © 2004 Royal Meteorological Society.
Models to improve winter minimum surface temperature forecasts, Delhi, India
Authors: Dimri A. P.
Published: June 2004

Accurate forecasts of minimum surface temperature during winter help in the prediction of cold‐wave conditions over northwest India. Statistical models for forecasting the minimum surface temperature at Delhi during winter (December, January and February) are developed by using the classical method and the perfect prognostic method (PPM), and the results are compared. Surface and upper air data are used for the classical method, whereas for PPM additional reanalysis data from the National Center of Environmental Prediction (NCEP) US are incorporated in the model development. Minimum surface temperature forecast models are developed by using data for the winter period 1985–89. The models are validated using an independent dataset (winter 1994–96). It is seen that by applying PPM, rather than the classical method, the model's forecast accuracy is improved by about 10% (correct to within ± 2 °C). Copyright © 2004 Royal Meteorological Society.
A new intensity‐scale approach for the verification of spatial precipitation forecasts
Authors: Casati B. , Ross G. , Stephenson D. B.
Published: June 2004

A new intensity‐scale method for verifying spatial precipitation forecasts is introduced. The technique provides a way of evaluating the forecast skill as a function of precipitation rate intensity and spatial scale of the error. Six selected case studies of the UK Met Office now‐casting system NIMROD are used to illustrate the method.

The forecasts are assessed using the Mean Squared Error (MSE) skill score of binary images, obtained from the forecasts and analyses by thresholding at different precipitation rate intensities. The skill score is decomposed on different spatial scales using a two‐dimensional discrete Haar wavelet decomposition of binary error images. The forecast skill can then be evaluated in terms of precipitation rate intensity and spatial scale.

The technique reveals that loss of forecast skill in NIMROD is predominantly due to small spatial scale (<40 km) errors of more intense events. The technique is capable of isolating specific intensity‐scale errors for individual cases. As an example, in one of the case studies the displacement error of an incorrectly advected storm is well detected by a minimum negative skill score occurring at the 160 km spatial scale for thresholds between 1/2 and 4 mm/h. Copyright © 2004 Royal Meteorological Society.
On the use of advanced Doppler radar techniques to determine horizontal wind fields for operational weather surveillance
Authors: Friedrich Katja , Hagen Martin
Published: June 2004

The purpose of this paper is to show how already existing Doppler radar information, provided, for example, by the German Weather Service's (DWD) radar network, can be combined to wind vector fields using multiple‐Doppler techniques. At the same time, an alternative to monostatic multiple‐Doppler measurements, called a bistatic Doppler radar network, is introduced to measure wind velocity within areas which are not covered by the multiple‐Doppler technique or where wind fields close to the earth's surface are required. Advantages, disadvantages, principles and measurement characteristics of the two systems are specified. Additionally, a recommendation is given to arrange each instrument optimally within the network in order to measure wind velocities close to the ground over large areas with high spatial resolution and low error variance. Both systems are applicable either to derive wind fields throughout weather radar networks as shown using the DWD weather radar network, or to act as the basis for weather warning and advisory systems in operation, for instance, at Frankfurt/Main International Airport. Concepts for both applications are given. Copyright © 2004 Royal Meteorological Society.
Adaptive Kalman filtering of 2‐metre temperature and 10‐metre wind‐speed forecasts in Iceland
Authors: Crochet Philippe
Published: June 2004

In this paper, an adaptive Kalman filtering procedure is developed and applied to 2‐metre temperature and 10‐metre wind‐speed forecasts in Iceland. The goal is to reduce the systematic bias and improve the accuracy of the local forecasts derived from a numerical weather prediction model and, in addition, to produce reliable prediction intervals. The method consists of adding two algorithms to the traditional Kalman filter procedure that adaptively estimate the noise statistics individually at each forecast location and each time step. The tested data set shows that the method is able to remove the systematic errors and to quantify the prediction uncertainty in a consistent manner. Copyright © 2004 Royal Meteorological Society.
The worlds of welfare: illusory and gender blind?
Authors: Bambra Clare
Published: June 2004

The nature of welfare state regimes has been an ongoing debate within the comparative social policy literature since the publication of Esping-Andersen's The Three Worlds of Welfare Capitalism (1990). This paper engages with two aspects of this debate; the gender critique of Esping-Andersen's thesis, and Kasza's (2002) assertions about the ‘illusory nature’ of welfare state regimes. It presents a gender-focused defamilisation index and contrasts it with Esping-Andersen's decommodification index to illustrate that, whilst individual welfare states have been shown to exhibit internal variety across different policy areas, they are both consistent and coherent in terms of their policy variation by gender. It concludes, in contrast to both the gender critique of Esping-Andersen, and Kasza's rejection of the regimes concept, that the ‘worlds of welfare’ approach is therefore neither gender blind or illusory, and can, if limited to the analysis of specific areas such as labour market decommodification or defamilisation, be resurrected as a useful means of organising and classifying welfare states.
Work–life Balance and Working from Home
Authors: Crosbie Tracey , Moore Jeanne
Published: June 2004

In recent years, there has been increasing focus on the question of how to balance work and life commitments in both academic and political debates. Homeworking is one initiative that has been promoted as a way of improving the work–life balance. This paper examines the experience of homeworking drawing on a recently completed ESRC study on homeworkers. Using the data from 45 interviews and 3 focus groups with homeworkers from different socio-economic backgrounds, it explores the question of whether working (or not) from home improves people's capacity to balance their work and life commitments.
Health Care Rationing Policy in New Zealand: Development and Lessons
Authors: Gauld Robin
Published: June 2004

This article discusses New Zealand's experiences with health care rationing policy. It reviews attempts to define ‘core services’, the development of prioritisation techniques for service access and funding, new technology assessment, and the management of subsidised pharmaceuticals. The New Zealand experience offers various lessons: that rationing policy development is, by nature, a ‘messy’ process; that central coordination of rationing policy is crucial unless differentiation in regional initiatives and service access are desired; and that through ongoing highlighting of the need for it, rationing policy development is likely to become an accepted reality.
The Mechanism of Income Redistribution: The Case of South Korea
Authors: Hwang Gyu-Jin
Published: June 2004

This article presents a case study of income redistribution in South Korea. By analysing the most comprehensive household income survey (National Survey of Family Income and Expenditure), it identifies a growing sign of change regarding the extent to which social security is beginning to play an important role in reducing income inequality. Nonetheless, it argues that its impact is yet to be sizeable enough to make a significant difference and, still further, that social security is of little use in terms of mitigating increasing inequality of original incomes which comprise the largest part of gross income.
An Overview: Themed Section on Globalisation and Welfare Systems in Asia
Authors: Chan Raymond K.H.
Published: June 2004

The latest period of expansion in the international economy has been characterised by the liberalisation of capital movements, the deregulation of major financial markets and the spread of neo-liberal beliefs in the merits of open and competitive trade, the disadvantages of big government and protectionist policies (Hirst, 1997). The rapid advancement of information and communication technology and the growth of knowledge-based economy have led to the gradual replacement of the conventional resource-based economies. ‘A techno-economic paradigm of information and communications technology and the knowledge-based economy has created a new knowledge-elite class that favours free markets in this post-industrial society, characterized by globalization, decentralization, deregulation and privatization’ (Low, 2003: 30–31).
Changing Approaches of Social Protection: Social Assistance Reform in Urban China
Authors: Shang Xiaoyuan , Wu Xiaoming
Published: June 2004

The article will examine the latest development of China's urban social assistance reform. Under the impact of the dual processes of globalisation and the deepening market transition, China's social security reform is increasingly taking a new safety net approach to assist the urban poor, instead of relying mainly on social insurance provision. The minimum living security project for urban residents is one of the approaches supplementing social insurance in social protection. In 2002, about one-third of social security beneficiaries were supported by the newly developed social assistance project. The changing approach does not mean that the government is withdrawing from its responsibility for social insurance to the urban workers, but reflects the changing goals and means of social policies. This indicates that China's social welfare system is shifting towards a new residual welfare model.
How Singapore's Central Provident Fund Fares in Social Security and Social Policy
Authors: Low Linda
Published: June 2004

Singapore's Central Provident Fund (CPF) has served well in the old economy as a macroeconomic stabilisation policy. It finessed the developmental state and created socio-political stability with home ownership extended to health, education and asset enhancement schemes. However, structural changes with globalisation, information communication technology (ICT) and the new knowledge-based economy (KBE), plus a series of crises and downturns since the Asian crisis have undermined full employment as the lynchpin of the triangulation and CPF model. Announcements made in August 2003 are germane to this paper's discussion of the reinvention of the CPF model. Profound and creative reinvention to balance between neo-liberal market-based solutions without losing the socio-political control enjoyed by the ruling regime, however, remains a political choice as in delinking the CPF–fiscal process, CPF serves members or state.
Is There a Way Out? Global Competition and Social Reform in Taiwan
Authors: Ku Yeun-wen
Published: June 2004

Globalisation, and its possible impacts, has been widely discussed and debated in Taiwan. The economic technocracies argue for globalisation, as a triumph of the free market and minimum state intervention, through measures of tax cuts, privatisation, deregulation, and so forth, as required to secure Taiwan's economic development in the future. However, rising unemployment accompanied by the new poverty requires more state provisions of social welfare. A strange policy orientation mixing tax cuts with welfare increases is proposed that precisely demonstrates the dilemma of the state between global competition and social reform. This is now a great challenge for Taiwan to balance economic and social requirements.
Issues in Globalisation and Social Welfare in Asia
Authors: Ramesh M.
Published: June 2004

I started this paper with the objective of reviewing the literature on globalisation and welfare state in East Asia but quickly found that there was little available to review. Not only are there few published works on the topic, they are often too general or abstract to enlighten the subject. I accordingly redefined the paper's objective as reviewing the arguments on globalisation's impact on the Western welfare state and relating them to social welfare in East Asia. I will argue that globalisation's impact on social welfare in East Asia is even more multi-faceted and divergent than is the case in the Western world, due to domestic political conditions specific to the region.
Some Useful Sources
Authors: Chan Raymond K.H.
Published: June 2004

Those who would like to explore more on the issue, apart from looking at the references of each article, can find more information and analysis from these items supplied by authors of the articles, which are arranged by four parts: general, general-Asia, country-specific and statistics.
Effects of bottom water warming and sea level rise on Holocene hydrate dissociation and mass wasting along the Norwegian‐Barents Continental Margin
Authors: Jung Woo‐Yeol , Vogt Peter R.
Published: June 2004

Gas hydrate (GH) stability modeling results explain why some major Holocene submarine landslides along the Norwegian‐Barents margin could have been triggered by GH dissociation during the early to middle Holocene, not during the lowest sea levels of the Last Glacial Maximum (LGM). Our model results show that subbottom depths of 170–260 m below the pre‐slide continental slope (ca. 350–475 m present water depth) must have passed out of gas hydrate stability zone (GHSZ) by 8.15 ka as the effect of warm bottom water inflow at 11 ka penetrated into the subbottom, overcoming the effects of pressure increase due to sea level rise (SLR). The component of local SLR due to the isostatic response to Fennoscandian deglaciation is shown to be relatively insignificant, particularly for the part of the upper continental slope where the slide probably began. The stability relations show that GH could have formed under the ice sheet before deglaciation, and below deeper shelf areas after sea levels began to rise, but before significant warming near the GHSZ base. To the extent water deeper than 800 m has remained cold (−1° to 0°C) since LGM times, the GHSZ continued to thicken in deep water and GH dissociation could not have triggered Holocene failure in that regime. The present distribution of GH stability is limited to water depths greater than about 400 m in the Storegga slide area, and the thickness of the GHSZ increases with water depth.
A model of deep crustal fluid flow following the Mw = 8.0 Antofagasta, Chile, earthquake
Authors: Koerner A. , Kissling E. , Miller S. A.
Published: June 2004

We develop a model to test the hypothesis that a high fluid pressure pulse and subsequent fluid flow caused a spatially extensive increase in the VP/VS ratio following the Mw = 8.0 Antofagasta, Chile, subduction zone earthquake. The postseismic anomaly appeared within a 50‐day period inside the forearc region of the Andes continental crust. We model this anomaly with a poroelastic medium that combines the fluid flow response to mean stress changes from slip along a dislocation plane, with a pore pressure pulse initiated by the coseismic rupturing of a seal separating hydrostatic‐lithostatic fluid pressure conditions in the hanging walls and footwalls of the subduction zone, respectively. Variations in seismic velocity due to porosity and pore pressure changes are calculated using Gassmann's formula and the empirical law of critical porosity. We show that the slip‐induced perturbation of the mean stress field is insufficient to explain the anomaly, but the release of lithostatic pressurized fluid trapped below the rupture plane (within the oceanic crust) can explain the transient changes in seismic velocities. Our preferred model requires a very large intrinsic permeability of around 1 × 10−13m2, suggesting a mechanism of a high‐amplitude pressure pulse propagating through a highly permeable fracture system of the lower continental crust.
Biases in the air‐sea flux of CO2 resulting from ocean surface temperature gradients
Authors: Ward B. , Wanninkhof R. , McGillis W. R. , Jessup A. T. , DeGrandpre M. D. , Hare J. E. , Edson J. B.
Published: June 2004

The difference in the fugacities of CO2 across the diffusive sublayer at the ocean surface is the driving force behind the air‐sea flux of CO2. Bulk seawater fugacity is normally measured several meters below the surface, while the fugacity at the water surface, assumed to be in equilibrium with the atmosphere, is measured several meters above the surface. Implied in these measurements is that the fugacity values are the same as those across the diffusive boundary layer. However, temperature gradients exist at the interface due to molecular transfer processes, resulting in a cool surface temperature, known as the skin effect. A warm layer from solar radiation can also result in a heterogeneous temperature profile within the upper few meters of the ocean. Here we describe measurements carried out during a 14‐day study in the equatorial Pacific Ocean (GasEx‐2001) aimed at estimating the gradients of CO2 near the surface and resulting flux anomalies. The fugacity measurements were corrected for temperature effects using data from the ship's thermosalinograph, a high‐resolution profiler (SkinDeEP), an infrared radiometer (CIRIMS), and several point measurements at different depths on various platforms. Results from SkinDeEP show that the largest cool skin and warm layer biases occur at low winds, with maximum biases of −4% and +4%, respectively. Time series ship data show an average CO2 flux cool skin retardation of about 2%. Ship and drifter data show significant CO2 flux enhancement due to the warm layer, with maximums occurring in the afternoon. Temperature measurements were compared to predictions based on available cool skin parameterizations to predict the skin‐bulk temperature difference, along with a warm layer model.
Neural network retrieval of cloud parameters of inhomogeneous clouds from multispectral and multiscale radiance data: Feasibility study
Authors: Cornet Céline , Isaka Harumi , Guillemet Bernard , Szczap Frédéric
Published: June 2004

In this paper, we investigated the feasibility of retrieving cloud parameters of inhomogeneous and fractional clouds from simulated multispectral and multiscale radiometric data by using mapping neural networks. A radiometric database prepared for neural network training consists of area‐averaged radiance data for two pixel scales, i.e., (1 km × 1 km) and (0.25 km × 0.25 km) pixels, respectively. The cloud parameter retrieval assumes a vertically uniform inhomogeneous and fractional cloud defined with 6 parameters, i.e., the mean and standard deviation of optical thickness, the mean and standard deviation of effective radius, the fractional cloud cover, and the cloud top temperature, all defined at a scale of cloud parameter retrieval. The retrieval procedure comprises two separate steps: the first one is relative to the angular interpolation and correction of radiance data (surface reflection and thermal emission contribution). The second step concerns the cloud parameter retrieval as such from interpolated and corrected radiance data. The input vector to the retrieval MNNs consists of 8 radiometric data in addition to a number of necessary ancillary data such as surface temperature and ground albedo. The 8 radiometric data are 5 area‐averaged radiances over (1 km × 1 km) pixel and 3 standard deviations of radiance over (1 km × 1 km) pixel estimated from (0.25 km × 0.25 km) pixel radiances. After evaluating the performance of the neural networks trained for each step, we tested the whole retrieval procedure for three types of inhomogeneous and fractional clouds: flat‐top bounded cascade clouds and flat‐top and non‐flat‐top Gaussian process clouds. All the cloud parameters of these clouds can be retrieved with reasonable accuracy in spite of the fact that the mean and standard deviation of optical thickness of non‐flat‐top clouds exhibit some dispersion. The inclusion of (0.25 km × 0.25 km) pixel radiance data as input vector components improved significantly the performance of the cloud parameter retrieval. Finally, we analyzed the consequences of some simplifying assumptions on the retrieved cloud parameters, and discussed the perspectives of the cloud parameter retrieval based on the neural networks.
Oil and gas prospecting by ultra‐sensitive optical gas detection with inverse gas dispersion modelling
Authors: Hirst Bill , Gibson Graham , Gillespie Steve , Archibald Ian , Podlaha Olaf , Skeldon Kenneth D. , Courtial Johannes , Monk Steve , Padgett Miles
Published: June 2004

We report a new oil and gas prospecting technique based on measurements of sub‐part‐per‐billion ethane concentration in the atmosphere and local wind data. The sensitivity of our sensor enables detection, from a range of several km, of the naturally occurring ethane seepages that accompany hydrocarbon reservoirs. Using the concentration and wind data, the gas dispersion process is inverted to provide maps of surface ethane flux over several hundred km2. Within a desert environment, we demonstrate the technique is capable of locating a controlled release and corresponds with the results from a geochemical soil sampling survey conducted over the same oil field.
Observations of organic species and atmospheric ice formation
Authors: Cziczo D. J. , DeMott P. J. , Brooks S. D. , Prenni A. J. , Thomson D. S. , Baumgardner D. , Wilson J. C. , Kreidenweis S. M. , Murphy D. M.
Published: June 2004

Aerosol particles found in the lower confines of the atmosphere are typically internal mixtures of sulfate, inorganic salts, refractory components, and organic species. The effect these complex combinations have on cloud formation processes remains largely unknown. We have conducted two complementary studies on one important process, the homogeneous formation of ice by small particles. In the first study the freezing of atmospheric aerosol was induced using controlled temperature and humidity conditions. In the second study the chemical composition of the residue from ice crystals in high altitude clouds was analyzed. Here we show that organic components do not partition equally to the ice and aqueous phases. Instead, organic‐rich particles preferentially remain unfrozen. These results suggest that emissions of organic species have the potential to influence aerosol‐cold cloud interactions and climate.
A procedure for evaluating feedback mechanisms in coupled atmosphere/ocean climate models
Authors: Sun Moguo , Cess Robert D.
Published: June 2004

To understand inter‐model differences in long‐term simulations of climate change, as exist between coupled atmosphere/ocean general circulation models, it is necessary to first understand climate feedback mechanisms that operate within each of the various models. With this goal in mind, we have employed an 1870 to 1989 simulation, with prescribed increases in greenhouse gases, that was performed using the National Center for Atmospheric Research Community Climate System Model Version 1, as a vehicle for determining two feedback processes operating within that model. These are cloud feedback and snow/ice albedo feedback. A prerequisite to evaluating feedback mechanisms is to first evaluate the direct radiative forcing, caused by the increasing greenhouse gases, which produces global warming by the model, and a procedure for doing this is presented. Cloud feedback is then evaluated by referencing the model's change in global‐mean cloud‐radiative forcing to the direct greenhouse‐gas induced radiative forcing, and a comparable procedure is employed to determine snow/ice albedo feedback. This model produces a moderately strong negative cloud feedback and a modest positive snow/ice albedo feedback. But the main purpose of this study is to provide a reasonably simple procedure for determining both cloud feedback and snow/ice albedo feedback within coupled atmosphere/ocean GCMs.
The 1997/98 El Niño: A test for climate models
Authors: Lu Riyu , Dong Buwen , Cess Robert D. , Potter Gerald L.
Published: June 2004

Version 3 of the Hadley Centre Atmospheric Model (HadAM3) has been used to demonstrate one means of comparing a general circulation model with observations for a specific climate perturbation, namely the strong 1997/98 El Niño. This event was characterized by the collapse of the tropical Pacific's Walker circulation, caused by the lack of a zonal sea surface temperature gradient during the El Niño. Relative to normal years, cloud altitudes were lower in the western portion of the Pacific and higher in the eastern portion. HadAM3 likewise produced the observed collapse of the Walker circulation, and it did a reasonable job of reproducing the west/east cloud structure changes. This illustrates that the 1997/98 El Niño serves as a useful means of testing cloud‐climate interactions in climate models.
Detection of volcanic influence on global precipitation
Authors: Gillett N. P. , Weaver A. J. , Zwiers F. W. , Wehner M. F.
Published: June 2004

Observations of terrestrial precipitation from the latter half of the 20th century are compared with precipitation simulated by the Parallel Climate Model to determine which external forcings have had a detectable influence on precipitation. Consistent with a previous study using another model, we found that the global mean response to all forcings combined was significantly correlated with that observed. A detection and attribution analysis applied to the simulated and observed precipitation indicated that the volcanic signal is detectable both on its own and in a multiple regression with other forcings. These results are consistent with the hypothesis that shortwave forcings exert a larger influence on precipitation than longwave forcings.
A Workshop for the Aviation Community
Authors: Kunches Joseph , Combs Larry , Murtagh William
Published: June 2004

On 23‐24 February 2004 at NOAA's Space Environment Center in Boulder, Colo., the SEC, Virgin Atlantic Airways, and SolarMetrics hosted an aviation workshop on integrating space weather information into the operating procedures for commercial airlines. The meeting, with representatives from the industrial and academic communities, led to the formation of the International Committee for Space Weather Impacts on Aviation Safety working group.
Identification of Lassa virus glycoprotein signal peptide as a trans‐acting maturation factor
Authors: Eichler Robert , Lenz Oliver , Strecker Thomas , Eickmann Markus , Klenk Hans‐Dieter , Garten Wolfgang
Published: June 2004

Lassa virus glycoprotein is translated as a precursor (pre‐GP‐C) into the lumen of the endoplasmic reticulum and is cotranslationally cleaved into the signal peptide and GP‐C, before GP‐C is proteolytically processed into its subunits GP1 and GP2. The signal peptide of pre‐GP‐C comprises 58 amino acids. The substitution of Lassa virus pre‐GP‐C signal peptide with another signal peptide still mediates translocation and the release of signal peptide but abolishes the proteolytic cleavage of GP‐C into GP1 and GP2. Remarkably, cleavage of GP‐C from these hybrid pre‐GP‐C substrates was restored on coexpression of the wild‐type pre‐GP‐C signal peptide, indicating that the signal peptide functions as a trans‐acting factor to promote Lassa virus GP‐C processing. To our knowledge, this is the first report on a signal peptide that is essential for proteolytic processing of a secretory pathway protein.
Potassium channel regulation
Authors: Campbell Jeff D , Sansom Mark S P , Ashcroft Frances M
Published: June 2004

The sulphonylurea receptor (SUR) is a member of the ATP‐binding cassette (ABC) family of membrane proteins. It functions as the regulatory subunit of the ATP‐sensitive potassium (KATP) channel, which comprises SUR and Kir6.x proteins. Here, we review data demonstrating functional differences between the two nucleotide binding domains (NBDs) of SUR1. In addition, to explain the structural basis of these functional differences, we have constructed a molecular model of the NBD dimer of human SUR1. We discuss the experimental data in the context of this model, and show how the model can be used to design experiments aimed at elucidating the relationship between the structure and function of the KATP channel.
Identification of a family of endocytic proteins that define a new α‐adaptin ear‐binding motif
Authors: Ritter Brigitte , Philie Jacynthe , Girard Martine , Tung Elaine C , Blondeau Francois , McPherson Peter S
Published: June 2004

Endocytosis by clathrin‐coated vesicles (CCVs) is an important mechanism mediating protein internalization. Here, we show that two proteins identified through a proteomics analysis of CCVs are new components of the endocytic machinery. The proteins, named NECAP (adaptin‐ear‐binding coat‐associated protein) 1 and 2, are paralogues that display no sequence similarity or common domains with any known protein. Both are enriched in CCV coats, and further analysis of the brain‐enriched isoform, NECAP 1, shows its partial localization to clathrin‐coated pits and direct binding to the globular ear domain of the α‐adaptin subunit (α‐ear) of the adaptor protein 2 (AP‐2) complex. Intriguingly, this interaction is mediated by a new motif, WVQF, that uses a distinct α‐ear interface relative to known α‐ear‐binding partners. Disruption of this interaction blocks clathrin‐mediated endocytosis. Together, our studies identify a new family of endocytic proteins that define a unique AP‐2‐binding motif.
Basolateral targeting by leucine‐rich repeat domains in epithelial cells
Authors: Legouis Renaud , Jaulin‐Bastard Fanny , Schott Sonia , Navarro Christel , Borg Jean‐Paul , Labouesse Michel
Published: June 2004

The asymmetric distribution of proteins to basolateral and apical membranes is an important feature of epithelial cell polarity. To investigate how basolateral LAP proteins (LRR (for leucine‐rich repeats) and PDZ (for PSD‐95/Discs‐large/ZO‐1), which play key roles in cell polarity, reach their target membrane, we carried out a structure–function study of three LAP proteins: Caenorhabditis elegans LET‐413, human Erbin and human Scribble (hScrib). Deletion and point mutation analyses establish that their LRR domain is crucial for basolateral membrane targeting. This property is specific to the LRR domain of LAP proteins, as the non‐LAP protein SUR‐8 does not localize at the basolateral membrane of epithelial cells, despite having a closely related LRR domain. Importantly, functional studies of LET‐413 in C. elegans show that although its PDZ domain is dispensable during embryogenesis, its LRR domain is essential. Our data establish a novel paradigm for protein localization by showing that a subset of LRR domains direct subcellular localization in polarized cells.
Efficient transgenesis in farm animals by lentiviral vectors
Authors: Hofmann Andreas , Kessler Barbara , Ewerling Sonja , Weppert Myriam , Vogg Barbara , Ludwig Harald , Stojkovic Miodrag , Boelhauve Marc , Brem Gottfried , Wolf Eckhard , Pfeifer Alexander
Published: June 2004

Microinjection of DNA is now the most widespread method for generating transgenic animals, but transgenesis rates achieved this way in higher mammals are extremely low. To address this longstanding problem, we used lentiviral vectors carrying a ubiquitously active promoter (phosphoglycerate kinase, LV‐PGK) to deliver transgenes to porcine embryos. Of the 46 piglets born, 32 (70%) carried the transgene DNA and 30 (94%) of these pigs expressed the transgene (green fluorescent protein, GFP). Direct fluorescence imaging and immunohistochemistry showed that GFP was expressed in all tissues of LV‐PGK transgenic pigs, including germ cells. Importantly, the transgene was transmitted through the germ‐line. Tissue‐specific transgene expression was achieved by infecting porcine embryos with lentiviral vectors containing the human keratin K14 promoter (LV‐K14). LV‐K14 transgenic animals expressed GFP specifically in basal keratinocytes of the skin. Finally, infection of bovine oocytes after and before in vitro fertilization with LV‐PGK resulted in transgene expression in 45% and 92% of the infected embryos, respectively.
Hexameric ring structure of the full‐length archaeal MCM protein complex
Authors: Pape Tillmann , Meka Hedije , Chen Shaoxia , Vicentini Giorgia , van Heel Marin , Onesti Silvia
Published: June 2004

In eukaryotes, a family of six homologous minichromosome maintenance (MCM) proteins has a key function in ensuring that DNA replication occurs only once before cell division. Whereas all eukaryotes have six paralogues, in some Archaea a single protein forms a homomeric assembly. The complex is likely to function as a helicase during DNA replication. We have used electron microscopy to obtain a three‐dimensional reconstruction of the full‐length MCM from Methanobacterium thermoautotrophicum. Six monomers are arranged around a sixfold axis, generating a ring‐shaped molecule with a large central cavity and lateral holes. The channel running through the molecule can easily accommodate double‐stranded DNA. The crystal structure of the amino‐terminal fragment of MCM and a model for the AAA+ hexamer have been docked into the map, whereas additional electron density suggests that the carboxy‐terminal domain is located at the interface between the two domains. The structure suggests that the MCM complex is likely to act in a different manner to traditional hexameric helicases and is likely to bear more similarity to the SV40 large T antigen or to double‐stranded DNA translocases.
Giant Hall resistance in Pt-based ferromagnetic alloys
Authors: Miao G. X. , Xiao Gang
Published: June 2004

We report on the observation of a dramatically increased extraordinary Hall Effect in Pt-based ferromagnetic alloy thin films with varying composition and thickness that were deposited using magnetron sputtering. Hall slope as high as 76.8 μΩ cm/T has been obtained at 110 K and 22.6 μΩ cm/T at 300 K. Excellent sensitivity, linearity, and a small temperature coefficient have been achieved in a particular composition, Fe35Pt65, for a film thickness of 10 nm. The optimized Fe–Pt thin films compare favorably with the commonly used semiconductor Hall sensors.
Scanning electron microscopy of field-emitting individual single-walled carbon nanotubes
Authors: Nojeh Alireza , Wong Wai-Kin , Baum Aaron W. , Pease R. Fabian , Dai Hongjie
Published: June 2004

Carbon nanotubes are promising electron emitters because of their sharp geometries that lead to significant external field enhancement, as well as their mechanical strength. However, distinguishing the emission due to an individual single-walled carbon nanotube (SWCNT) from that due to surrounding structures is a challenge. Here, we demonstrate how a scanning electron microscope (SEM) can be used to view the emission from individual SWCNTs by applying an external field close to the onset of field-emission and then scanning the tube with the electron beam of the SEM. The stimulated emission is revealed in the SEM image as localized bright spots.
Magnetic flux pinning enhancement in HgBa2CaCu2O6+δ films on vicinal substrates
Authors: Xie Y. Y. , Wu J. Z. , Yun S. H. , Emergo R. , Aga R. , Christen D. K.
Published: June 2004

High-temperature superconducting HgBa2CaCu2O6+δ films were fabricated on the vicinal surfaces of 4°-miscut SrTiO3 single crystal substrates in a cation-exchange process, with the purpose to induce additional growth defects via a step-flow growth mode on the miscut substrates. The critical current densities (Jc) of these films were measured using a standard four-probe method with magnetic fields applied perpendicular to the film surface. The vicinal Hg-1212 films indeed showed higher Jc’s in magnetic fields and irreversibility fields (Hirr) than that on 0°-cutSrTiO3. Hirr at 77K is 2.1T for the film grown 0°-cut SrTiO3, and is enhanced to 2.7T for the one grown on 4°-miscut SrTiO3. If optimized so that the shape and the density of the defects can be controlled experimentally, this may be a promising way of improve magnetic flux pinning for many practical applications related to coated conductors.
Metal delocalization and surface decoration in direct-write nanolithography by electron beam induced deposition
Authors: Gopal Vidyut , Stach Eric A. , Radmilovic Velimir R. , Mowat Ian A.
Published: June 2004

The ability to interconnect different nanostructures is crucial to nanocircuit fabrication efforts. A simple and versatile direct-write nanolithography technique for the fabrication of interconnects is presented. Decomposition of a metalorganic precursor gas by a focused electron beam resulted in the deposition of conductive platinum nanowires. The combination of in situ secondary electron imaging with deposition allows for the simultaneous identification and interconnection of nanoscale components. However, the deposition was not entirely localized to the electron beam raster area, as shown by secondary ion mass spectrometry measurements. The electrical impact of the metallic spread was quantified by measuring the leakage current between closely spaced wires. The origins of the spread and strategies for minimizing it are discussed. These results indicate that, while this direct-write methodology is a convenient one for rapid prototyping of nanocircuits, caution must be used to avoid unwanted decoration of nanostructures by metallic species.
Photoluminescence of a tensilely strained silicon quantum well on a relaxed SiGe buffer layer
Authors: Boucaud P. , El Kurdi M. , Hartmann J. M.
Published: June 2004

We have investigated the photoluminescence of tensilely strained silicon layers grown on relaxed SiGe buffer layers. At low excitation densities, the photoluminescence is dominated by the radiative recombinations associated with the dislocations in the buffer layer and the band-edge luminescence of the relaxed SiGe layers. We show that the photoluminescence of a strained silicon quantum well capped by a relaxed SiGe layer can be observed at high excitation densities. The resonance energy of this photoluminescence, observed around 960meV for the phonon-assisted transition, is in satisfying agreement with the calculated value of the bandgap of the type II strained heterostructure.
Drastic enhancement of nanoelectromechanical-system fabrication yield using electron-beam deposition
Authors: Koenig Daniel R. , Scheible Dominik V. , Blick Robert H.
Published: June 2004

The most common fabrication processes of nanoelectromechanical structures usually start with a silicon-on-insulator chip and incorporate several lithography and etch steps. The wet etch step, which involves hydrofluoric acid, is generally the most critical of these processing steps. In this letter, we present an enhancement of the wet etch step which relies on electron-beam deposition. The technique of electron-beam deposition utilizes a protective carbon layer which is applied by a scanning electron microscope. It allows us to resolve typical problems associated with the wet etch step and drastically increases the yield.