bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal variations of the trace fossil Zoophycos in a 425 ka long sediment record from the South China Sea: implications for the ethology of the Zoophycos producer
Authors: LÖWEMARK LUDVIG , LIN HUI-LING , SARNTHEIN MICHAEL
Published: December 2005

A 425 ka long record from piston core GIK17925-3 taken in the northeastern South China Sea was used to study the environmental conditions controlling the distribution of the Zoophycos trace fossil. The 12 m long core offers a unique opportunity to study the response of the Zoophycos-producing animal to environmental variations over four glacial–interglacial cycles. The trace fossils show a strong glacial to interglacial variation in their abundance with a special preference for intervals with low sedimentation rates. Additional X-ray radiograph studies of piston cores from the Southeast Asian Marginal Seas show that the trace fossil Zoophycos is widespread in slope and deep-marine sediments, with the highest abundances encountered in low sedimentation rate settings. The preference of the Zoophycos producer for low sedimentation rates in a setting with strong seasonal fluctuations in food supply due to the shift between winter and summer monsoons, is interpreted to be the result of a cache-model behaviour, where food is collected during rich times and squirrelled away for poor times. Core GIK17925-3 also offers an opportunity to assess the impact of Zoophycos bioturbation on various palaeoenvironmental proxies. In this core, more than 30 % of the measured data points were more or less strongly affected by Zoophycos bioturbation. Together with the widespread occurrence this percentage indicates that Zoophycos may pose a serious threat to palaeoclimatic reconstructions in cores from low to moderate sedimentation rate sites.
Study of the collapse of granular columns using two-dimensional discrete-grain simulation
Authors: STARON L. , HINCH E. J.
Published: December 2005

Numerical simulations of the collapse and spreading of granular columns onto a horizontal plane using the Contact Dynamics method are presented. The results are in agreement with previous experimental work. The final shape of the deposit appears to depend only on the initial aspect ratio a of the column. The normalized runout distance has a power-law dependence on the aspect ratio a, a dependence incompatible with a simple friction model. The dynamics of the collapse is shown to be mostly controlled by a free fall of the column. Energy dissipation at the base of the column can be described simply by a coefficient of restitution. Hence the energy available for the sideways flow is proportional to the initial potential energy $E_0$. The dissipation process within the sideways flow is approximated well by basal friction, unlike the behaviour of the runout distance. The proportion of mass ejected sideways is shown to play a determining role in the spreading process: as a increases, the same fraction of initial potential energy $E_0$ drives an increasing proportion of the initial mass against friction. This gives a possible explanation for the power-law dependence of the runout distance on a. We propose a new scaling for the runout distance that matches the data well, is compatible with a friction model, and provides a qualitative explanation of the column collapse.
Three-dimensional vortex structures under breaking waves
Authors: WATANABE YASUNORI , SAEKI HIROSHI , HOSKING ROGER J.
Published: December 2005

The large-scale vortex structures under spilling and plunging breakers are investigated, using a fully three-dimensional large-eddy simulation (LES). When an overturning jet projecting from the crest in a breaking wave rebounds from the water surface ahead, the vorticity becomes unstable in a saddle region of strain between the rebounding jet and a primary spanwise vortex, resulting in spanwise undulations of the vorticity. The undulations are amplified on a braid in this saddle region, leading to a vortex loop with counter-rotating vorticity. This vortex loop consequently envelops adjacent primary vortices, to form a typical rib structure. This rib component (the stretched vortex loop) in the large-scale vortex structure, which intensifies in the strains associated with the multiple primary vortices generated throughout the splash-up cycle, appears to be the previously found obliquely descending eddy.
Theory of two-layer hydraulic exchange flows with rotation
Authors: RIEMENSCHNEIDER ULRIKE , SMEED DAVID A. , KILLWORTH PETER D.
Published: December 2005

Two-layer rotating exchange flows through channels of rectangular cross-section are modelled using semi-geostrophic, zero-potential-vorticity theory. For a given channel cross-section the full range of possible flow states is considered. The interface always has a uniform slope across the channel, but may separate from one or both of the sidewalls to attach to the upper or lower boundary. The flow may be subcritical, critical or supercritical. These different states are identified in a pseudo-Froude-number plane analogous to that developed by Armi (1986) for non-rotating flows. If the ratio of the channel width to the Rossby radius is constant along the length of the channel, then the solution may be traced along the entire channel using a single diagram. Several examples of maximal and submaximal exchanges are considered. This graphical method of solution is contrasted with the functional approach of Dalziel (1988, 1990).

The exchange flux is determined as a function of the channel geometry, the strength of rotation and the difference in Bernoulli potential between the two layers.
Cross-national comparisons of human resources for health – what can we learn?
Authors: DUBOIS CARL-ARDY , MCKEE MARTIN
Published: December 2005

After a long period of neglect, the issue of human resources for health (HRH) has recently emerged as a core component on the international health agenda, with policy makers increasingly eager to learn from experience elsewhere. This article investigates systematically the opportunities and challenges associated with the use of cross-national comparisons of HRH policies and practices. It reviews the evidence in favour of using international comparative studies on HRH, discusses emerging opportunities for developing a cross-national research agenda to guide HRH policies in Europe, and highlights obstacles which may hinder the implementation of comparative studies on HRH. While demonstrating many opportunities offered by the comparative approach to improve understanding of human resources processes in the health sector, this article also emphasizes the dangers of simplistic pleas for the transfer of human resource policies without taking into account the context-specific factors and the generative capacity of the social actors in the design and implementation of policy changes.
Does greater Medicare HMO enrollment cause adverse selection into Medigap?
Authors: DESMOND KATHERINE A. , RICE THOMAS , FOX PETER D.
Published: December 2005

This paper examines the interaction between public and private insurance in the context of the US Medicare program, which serves those aged 65 and older as well as the disabled who meet specific eligibility requirements. Specifically, the paper examines the extent to which increasing enrollment in Medicare managed care (which provides more comprehensive coverage than basic Medicare) influences premiums in the privately purchased Medicare supplemental insurance market (called ‘Medigap’). We employ a fixed effects instrumental variables approach to analyze the association between premiums charged by two large Medigap insurers and Medicare HMO penetration rates, examining over 60 geographic areas during the period 1994–2000. It is hypothesized that greater Medicare HMO penetration will lead to adverse selection into the Medigap market, resulting in higher premiums. The findings suggest a moderate upward effect on premiums, with elasticities ranging from 0.09 to 0.25. Controlling for other factors, moving from a 12% to a 22% Medicare HMO penetration rate would raise average Medigap premiums from $1,314 to $1,615. We discuss the implications of these results with respect to the design of national health care systems that include both public and private insurers.
The trade in human organs in Tamil Nadu: the anatomy of regulatory failure
Authors: MURALEEDHARAN VANGAL R. , JAN STEPHEN , RAM PRASAD S.
Published: December 2005

There has been much recent interest in the trade in human organs in India. This paper examines both the extent to which regulatory controls through the Transplantation of Human Organs Act (1994) are effective in curbing commercialization and the nature of the constraints on the effective implementation of this Act. The study, a politico-economic analysis of health sector regulation, is based on a stakeholder analysis drawing on the views of key decision makers, service providers, organ donors and recipients. The findings indicate widespread acknowledgement of an organs trade and highlight four major constraints on the effective implementation of the Act: the commercial interests of middlemen and service providers, the ambiguities and loopholes in the Act; the low monitoring capacity of the regulatory authorities, and the pressures and responsibilities exerted upon the Authorizing Committees. A feature of the Act is that its implementation is subject to a major incentive compatibility constraint – it is seemingly not in the interests of any of the key players, including the regulatory authorities, to restrict the organ trade. To some extent, this institutional problem is created by the specific nature of the regulatory intervention, and, as a consequence, measures involving straightforward redrafting of the regulation might go some way to addressing this incentive problem. Another solution may entail a ‘harm-reduction’ strategy involving a controlled trade where procurement and organ matching is carried out by a government agency (this would require, however, the prior resolution of the broader ethical question concerning the legitimacy of such trade).
The great transformation
Authors: KLEIN RUDOLF
Published: December 2005

Over the past quarter century or so there has been, in Peter Hall’s formulation (Hall, 1993), a paradigm shift in macro-economic policy making: a movement from a Keynesian mode of policy making towards one based on monetary theory. The latter was open to a variety of interpretations and has been modified in practice. However, there was clearly a transformation in the way we think about economic policy making. Is the same true of social policy? Has there been an equivalent paradigm shift in the way we think about social policy? The two books under review provide an opportunity for addressing this question.
A game theoretic model of drug launch in India
Authors: BHADURI SARADINDU , RAY AMIT SHOVON
Published: December 2005

There is a popular belief that drug launch is delayed in developing countries like India because of delayed transfer of technology due to a ‘post-launch’ imitation threat through weak intellectual property rights (IPR). In fact, this belief has been a major reason for the imposition of the Trade Related Intellectual Property Rights regime under the WTO. This construct undermines the fact that in countries like India, with high reverse engineering capabilities, imitation can occur even before the formal technology transfer, and fails to recognize the first mover advantage in pharmaceutical markets. This paper argues that the first mover advantage is important and will vary across therapeutic areas, especially in developing countries with diverse levels of patient enlightenment and quality awareness. We construct a game theoretic model of incomplete information to examine the delay in drug launch in terms of costs and benefits of first move, assumed to be primarily a function of the therapeutic area of the new drug. Our model shows that drug launch will be delayed only for external (infective/communicable) diseases, while drugs for internal, non-communicable diseases (accounting for the overwhelming majority of new drug discovery) will be launched without delay.
Development of a Method To Analyze Single Cell Activity by Using Dielectrophoretic Levitation
Authors: Hakoda M. , Hachisu T. , Wakizaka Y. , Mii S. , Kitajima N.
Published: December 2005

In cell fusion and genetic recombination, although the activity of single cells is extremely important, there is no method to analyze single cell activity. Development of a quick analyzing method for single cell activity is desired in various fields. Dielectrophoresis (DEP) refers to the force exerted on the induced dipole moment of an uncharged dielectric and/or conductive particle by a nonuniform electric field. By applying DEP, we obtained experimentally a relationship between the cell activity and the dielectric property, Re[K(ω)], and examined how to evaluate the single cell activity by measuring Re[K(ω)] of a single cell. A cone and plate electrode geometry was adapted in order to achieve the feedback‐controlled DEP levitation. The single cell is exposed to a nonuniform field induced by the cone and plate electrode, and a more polarizable cell is moved to the direction of the cone electrode by the DEP force. The cell settles in the position where the DEP force and gravity are balanced by controlling applied voltage. This settled position, measured on the center axis of the cone electrode, depended on the dielectric constant of the cell. From these results, the relationship between the specific growth rates in cell growth phase and the dielectric properties Re[K(ω)] was obtained. Furthermore, the effect on the cell activity of various stresses, such as concentration of carbon dioxide, temperature, etc., was examined.
Kinetics of the Extraction of Succinic Acid with Tri‐n‐octylamine in 1‐Octanol Solution
Authors: Jun Young‐Si , Huh Yun Suk , Hong Won Hi , Hong Yeon Ki
Published: December 2005

Kinetic studies for the extraction of succinic acid from aqueous solution with 1‐octanol solutions of tri‐n‐octylamine (TOA) were carried out using a stirred cell with a microporous hydrophobic membrane. The interfacial concentrations of species were correlated and thus the intrinsic kinetics was obtained. The overall extraction process was controlled by the chemical reaction at or near the interface between the aqueous and organic phases. The formation reaction of succinic acid‐TOA complex was found to be first order with respect to the concentration of succinic acid in the aqueous phase and the order of 0.5 with respect to that of TOA in the organic phase with a rate constant of (3.14 ± 0.6) × 10−8 m2.5·mol−0.5·s−1. The dissociation reaction of succinic acid‐TOA complex was found to be the second‐order with respect to that of succinic acid‐TOA complex in the organic phase and the order of –2 with respect to that of TOA in the organic phase with a rate constant of (1.44 ± 1.4) × 10−4 mol·m−2·s−1.
Real‐Time Monitoring of Recombinant Bacterial Proteins by Mass Spectrometry
Authors: Jones Jeffrey J. , Wilkins Charles L. , Cai Ying , Beitle Robert R. , Liyanage Rohanna , Lay Jackson O.
Published: December 2005

Genetically altered bacteria manipulated to express green fluorescent protein (GFP) were used in an investigation of real‐time monitoring for recombinant protein expression in cell by matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight (TOF) mass spectrometry (MS). A significant advantage to whole cell MALDI MS is its ability to analyze bacterial cultures without pretreatment other than concentration. This paper describes the simultaneous analysis of overexpressed GFP recombinant Escherichia coliJM101 by MALDI‐TOF MS and standard fluorescence measurements. Cells were harvested from liquid culture media during a 12 h GFP induced expression cycle to demonstrate the feasibility of near real‐time monitoring of induced protein expression. The results show that although MALDI MS is not as sensitive as fluorescence measurements, expression levels of the targeted protein can easily be determined. Data available only through MALDI MS measurements reveal the presence of both native GFP and GFP‐(histidine)6 proteins. Additionally, biochemical processes not yet fully understood are observed in the presence and absence of ribosomal protein constituents. Thus, the work presented here demonstrates the ability of MALDI MS to monitor and characterize in real time the expression of targeted and unexpected genetically recombinant proteins in active cell cultures.
Free‐Standing Nanogold Membranes as Supports for the Growth of Calcium Phosphate Crystals
Authors: Rautaray Debabrata , Sastry Murali
Published: December 2005

Current strategies for bone tissue regeneration focus on the development of implantable matrices that mimic biological tissues. Inorganic composites are of special interest for bone substitute applications. It is necessary to create an artificial three‐dimensional scaffold‐like porous material with certain geometrical structure to induce bone growth. We report here the growth of calcium phosphate crystals on free‐standing carboxylic acid functionalized gold nanoparticle membranes. The gold nanoparticle membrane is synthesized by the spontaneous reduction of aqueous chloroaurate ions by a diamine molecule at a liquid‐liquid interface. This membrane is robust and malleable, and most importantly, the gold nanoparticles in the membrane may be functionalized with suitable ligands. In this study, the amino acids aspartic acid and cysteine together with an aromatic bifunctional molecule, anthranilic acid, were used to modify the surface of the gold nanoparticles in the membrane. The free carboxylic acid groups on the gold nanoparticles further to functionalization with these molecules were then used to bind Ca2+ ions and reacted with phosphate ions to yield calcium phosphate. The nature of the nanogold surface modifier directed the formation of either crystalline hydroxyapatite or amorphous calcium phosphate. The nanogold membrane thus suggests potential biomedical application as biocompatible implants and grafts.
Continuous Adsorption and Recovery of Cr(VI) in Different Types of Reactors
Authors: Bai Sudha R. , Abraham T. Emilia
Published: December 2005

This study reports the results of experiments on continuous adsorption and desorption of Cr(VI) ions by a chemically modified and polysulfone‐immobilized biomass of the fungus Rhizopus nigricans. A fixed quantity of polymer‐entrapped biomass beads corresponding to 2 g of dry biomass powder was employed in packed bed, fluidized bed, and stirred tank reactor for monitoring the continuous removal and recovery of Cr(VI) ions from aqueous solution and synthetic chrome plating effluent. Parameters such as flow rate (5, 10 and 15 mL/min), inlet concentration of Cr(VI) ions (50, 100, 150 and 250 mg/L) and the depth of biosorbent packing (22.8, 11.2 and 4.9 cm) were evaluated for the packed bed reactor. The breakthrough time and the adsorption rates in the packed bed column were found to decrease with increasing flow rate and higher Cr inlet concentrations and to increase with higher depths of sorbent packing. To have a comparative analysis of Cr adsorption efficiency in different types of reactors, the fluidized bed reactor and stirred tank reactor were operated using the same quantities of biosorbent material. For the fluidized bed reactor, Cr(VI) solution of 100 mg/L was pumped at 5 mL/min and fluidized by compressed air at a flow rate of 0.5 kg/cm.2 The stirred tank reactor had a working volume of 200 mL capacity and the inlet/outlet flow rate was 5 mL/min. The maximum removal efficiency (mg Cr/g biomass) was obtained for the stirred tank reactor (159.26), followed by the fluidized reactor (153.04) and packed bed reactor (123.33). In comparison to the adsorption rate from pure chromate solution, approximately 16% reduction was monitored for synthetic chrome plating effluent in the packed bed. Continuous desorption of bound Cr ions from the reactors was effective with 0.01 N Na2CO3 and nearly 80–94% recoveries have been obtained for all the reactors.
Quick Selection of a Chimeric T2 Phage That Displays Active Enzyme on the Viral Capsid
Authors: Tanji Yasunori , Murofushi Keita , Miyanaga Kazuhiko
Published: December 2005

We designed a bacteriophage T2 system to display proteins fused at the N‐terminus of the head protein small outer capsid (SOC) of a T2 phage. To facilitate selection of chimeric phage, a T2 phage encoding the β‐galactosidase gene (βgal) upstream of the soc gene was constructed. The phage, named T2βGal, produces blue plaques on agar plates containing XGal. Subsequently, a plasmid encoding the target protein upstream of soc was constructed and used to transform E. coli BE cells. Transformed cells were infected with T2βGal and homologous recombination between phage DNA and the plasmid resulted in a chimeric phage that produced transparent plaques due to the excision of the βgal gene. Chitosanase of Bacillus sp. strain K17 (ChoK), consisting of 453 amino acids, was used as a model target protein. Recombinant T2 phage that produced ChoK was named T2ChoK. T2ChoK was produced from T2βGal at a recombination frequency of about 0.1%. On the other hand, the value for T2βGal produced from wild‐type T2 was 0.001 %. This new system enables us to select recombinant phage very quickly and accurately. The number of molecules of ChoK was calculated at 14.7 per single phage. Latent period and burst size were estimated for the chimeric phages.
Variable Site‐Occupancy Classification of N‐Linked Glycosylation Using Artificial Neural Networks
Authors: Senger Ryan S. , Karim M. Nazmul
Published: December 2005

A novel neural‐network‐based model has been developed for the prediction of N‐linked glycosylation characteristics related to glycosylation site‐occupancy. Intracellular oligosaccharide transfer to a polypeptide is known to be either robust or dependent upon culture conditions during pharmaceutical production. This glycan attachment is classified by the model as robust or variable and is based on an input of the polypeptide primary sequence around the site of glycosylation. The glycosylation model utilizes multiple recurrent neural networks followed by a perceptron classifier. The input length of the polypeptide chain around the site of glycosylation (glycosylation window) was optimized through multiple independent training sessions. Incorporation of five residues prior (n – 5) to the site of glycosylation (n) and four residues beyond (n + 4) the glycan attachment site led to optimal network performance. The size of the glycosylation window for site‐occupancy determination is much larger than has been previously reported. This model was developed to evaluate the effects of theoretical polypeptide mutations on glycosylation site‐occupancy characteristics. Following correct prediction of the model testing data set, 20 independent networks were used to predict site‐occupancy characteristics of wild‐type and mutants of the rabies virus glycoprotein (rgp). Simulation results strongly correlated with previously published experimental results (Kasturi, L.; Hegang, C.; Shakin‐Eshleman, S. H. Regulation of N‐linked core glycosylation: use of a site‐directed mutagenesis approach to identify Asn‐Xaa‐Ser/Thr sequons that are poor oligosacchride acceptors. Biochem. J.1997, 323, 415–419. Mellquist, J. L.; Kasturi, L.; Spitalnik, S. L.; Shakin‐Eshleman, S. H. The amino acid following an Asn‐X‐Ser/Thr sequon is an important determinant of N‐linked core glycosylation efficiency. Biochemistry 1998, 37, 6833–6837). Further simulations on purely theoretical sequences suggested that influences of charged residues were a subset of multiple mechanisms in the determination of glycosylation site‐occupancy.
Molecular Characterization of Anaerobic Microbial Communities from Benzene‐Degrading Sediments under Methanogenic Conditions
Authors: Chang Wook , Um Youngsoon , Holoman Tracey R. Pulliam
Published: December 2005

Anaerobic benzene degradation was confirmed in microbial communities enriched from Baltimore Harbor (Baltimore, MD) sediments under methanogenic conditions. Molecular characterization based on 16S rDNA gene sequences revealed that the strains in the communities were diversely affiliated with such phylogenetic branches as the Bacteroidetes, Euryarchaeota, Firmicutes, and Thermotogaephyla. Of interest was that the majority of the microbial populations detected in these cultures were closely related to the members of dechlorinating microbial communities. Further, some of those species were previously found in naphthalene‐ or phenanthrene‐degrading methanogenic communities. Finally, this result could be used to design targeted isolation strategies for anaerobic benzene‐degrading strains under methanogenic conditions.
Bioengineering of a Cellulosic Fabric for Insecticide Delivery via Grafted Cyclodextrin
Authors: Romi Roberto , Nostro Pierandrea Lo , Bocci Eugenio , Ridi Francesca , Baglioni Piero
Published: December 2005

β‐Cyclodextrin (β‐CD) can be easily grafted onto cellulosic textiles through covalent bonds. In such a way β‐CD empty cavities provide an efficient tool for entrapping different kinds of hydrophobic molecules on the surface of the fabric and releasing them slowly in time. The capability of cyclodextrins to include hydrophobic molecules such as fragrances, antimicrobial agents, and other chemicals can be then exploited to produce new grafted textiles with peculiar and useful performances. In this work we report the inclusion of two different products, the pyrethroid insecticide permethrin (PERM) and the insect repellentN,N‐diethyl‐m‐toluamide (DEET), into β‐CD molecules grafted on cotton fabric. UV‐vis spectrophotometry and thermal analysis confirmed the presence of the guest molecules on the fabric surface. Bioassays were carried out on two mosquito species of medical importance,Aedes aegyptiandAnopheles stephensi; knock down effect and mortality were measured using standard World Health Organization (WHO) cone tests. Repellency and irritancy (blood feeding inhibition) were also measured using cage tests and a baited tunnel device. PERM‐treated fabrics kept the insecticidal/irritant efficacy even for a long time after the treatment, whereas DEET activity lasted more shortly.
Scientific Reasoning in Young Children: Preschoolers’ Ability to Evaluate Covariation Evidence
Authors: Koerber Susanne , Sodian Beate , Thoermer Claudia , Nett Ulrike
Published: December 2005

Preschool children’s basic scientific reasoning abilities were investigated in two experiments. Consistent with findings by Ruffman et al. (1993) , Experiment 1 showed that even 4-year-olds can evaluate patterns of covariation evidence. However, even 6-year-olds had difficulties interpreting non-covariation evidence. Experiment 2 showed that 5-year-olds could overcome this difficulty when prompted to expect no causal relationship between two variables. Experiment 2 further showed that preschoolers’ evidence evaluation skills were affected by their pre-existing causal beliefs. However, their performance was above chance even when the evidence contradicted a prior belief they held with some conviction. In sum, our results demonstrate a basic understanding of the hypothesis-evidence relationship in preschool children, thus contributing to a revision of the picture of the scientifically illiterate preschooler.
How Children Reason about Gains and Losses: Framing Effects in Judgement and Choice
Authors: Schlottmann Anne , Tring Jane
Published: December 2005

Three experiments considered how the positive or negative framing of decisions affects children’s EV (expected value) judgements and choices. In Experiment 1, 6- and 9-year-olds chose between a sure gain and a gamble or between a sure loss and a gamble, all with the same EV. Children preferred the sure thing more in the positive than negative frame, as also appears for adults. In Experiment 2, both frames involved potential losses. In their judgements, 6- and 9-year-olds used the normative multiplication rule for integrating risk and amount at risk, with minor frame differences, but when choosing between the same options, they were risk-averse in the save, risk-seeking in the loss frame. In Experiment 3, 5-year-olds used multiplication for saves, with an irregular pattern for losses. Overall, children’s judgements conform closely to normativity. At the same time, children’s choices, like adults’, show non-normative framing effects. This décalage may reflect the involvement of more intuitive processes in judgement than choice.
Acquiring a Theory of Biology: Knowledge about Inheritance in Children with Lower Intelligence
Authors: Mähler Claudia
Published: December 2005

Research on conceptual development in the domain of biology shows that young children with normal development are familiar with basic concepts but not yet with causal biological processes. Do children with lower IQ acquire the same knowledge at the same time? Two aspects of biological inheritance were examined: the distinction between inherited and acquired properties, and the relevant mechanism for inheritance. Twenty children at borderline of mental retardation (mean age: 10;3 years) participated in the study, and two groups of children with normal IQ served as controls, one matched for chronological and one for mental age. Results revealed an overall developmental lag for the children with lower intelligence. These children preferred an intentional mechanism as a causal explanation for inheritance, which rarely occurred in the control groups. This result could reflect a conceptual deficit and an immature theory of biology in children with lower IQ.
Can a Preschooler’s Mistaken Belief Benefit Learning?
Authors: Kloos Heidi , Van Orden Guy C.
Published: December 2005

Young children erroneously believe that differences either in mass alone or in volume alone can predict differences in sinking speed. The current study was an attempt to teach preschool children that neither mass nor volume alone is predictive for sinking speed. Instead, it is the average density of an object that can predict differences in sinking speed. Twenty-four 4-to 6-year-olds participated. In an initial phase, children’s mistaken beliefs about the effects of mass and volume on sinking speed were called to their minds. Then they were presented with demonstrations of sinking objects that disconfirmed these mistaken beliefs. The findings show that preschool children can replace mistaken beliefs and learn that two dimensions, originally thought of as being relevant, are indeed irrelevant. Children who did not perform correctly demonstrated a mass bias. The results also shed light on the origins of this bias.
Examination of type II origin with SOHO/LASCO observations
Authors: Cho K.‐S. , Moon Y.‐J. , Dryer M. , Shanmugaraju A. , Fry C. D. , Kim Y.‐H. , Bong S.‐C. , Park Y.‐D.
Published: December 2005

We examine a possibility that metric type II solar radio bursts are all caused by coronal mass ejection (CME) generated shocks. For this we consider 129 type II flare events from February 1997 to October 2000 and examine their associations with SOHO/LASCO CMEs according to their temporal and spatial closeness using SOHO/EIT and GOES data. We then carefully inspected 26 CME‐less events to examine if there are CME‐related features in LASCO and EIT images. In addition we examined 28 limb type II CME events to compare the kinematics of coronal shocks with those of the CME fronts. Under the assumption that the observed type IIs are all generated by CME‐related shocks, we determine the formation heights of the CME‐associated type IIs using LASCO CME speeds and type II onset times. From these studies, we have found (1) a large fraction (81%) of the type II bursts have temporal and spatial association with CMEs, and the association increases as their source position approaches to the limb; (2) most of the events without the association are related with weak flares and/or disk events; (3) most of the events are super‐Alfvenic with a mean speed of 900 km s−1; (4) the front heights of all CMEs except for a few events are in the range of 1 to 3 solar radii, which are consistent with the type II formation heights; (4) the onset time difference (CME‐type II) of all events are within about ±1 hour, mostly −30 min to 10 min; (5) the CME speeds have a possible correlation (r = 0.6) with coronal shock speeds, when two outliers are excluded. Considering a possibility that some outliers could result from some effects such as the coronal shock generation at CME flanks and CME accelerations, our results show that most of the type II bursts can be explained by the CME origin.
Impact of North Atlantic Current changes on the Nordic Seas and the Arctic Ocean
Authors: Kauker Frank , Gerdes Rüdiger , Karcher Michael , Köberle Cornelia
Published: December 2005

The impact of North Atlantic Current (NAC) volume, heat, and salt transport variability onto the Nordic Seas and the Arctic Ocean is investigated using numerical hindcast and sensitivity experiments. The ocean‐sea ice model reproduces observed propagation pathways and speeds of SST anomalies. Signals reaching the entrance to the Nordic Seas between Iceland and Scotland originate partly in the lower‐latitude North Atlantic. Response experiments with different prescribed conditions at 50°N show that changes in the barotropic flow across 50°N have no impact on the seas north of the Greenland‐Scotland Ridge because of the strong deformation of the f/H field. A temperature anomaly inserted in the upper 500 m at 50°N, on the other hand, has a widespread effect on the temperature distribution and the circulation in the high‐latitude North Atlantic. NAC induced variability in the Nordic Seas and locally induced variability have similar magnitude. The local atmospheric influence and the complexity of North Atlantic‐Nordic Seas advection pathways make it unlikely that detection of signal propagation in the NAC could lead to a prediction of oceanic conditions in the Nordic Seas and the Arctic Ocean with several years lead time.
Decadal variability of shallow cells and equatorial sea surface temperature in a numerical model of the Atlantic
Authors: Kröger Jürgen , Busalacchi Antonio J. , Ballabrera‐Poy Joaquim , Malanotte‐Rizzoli Paola
Published: December 2005

The relative role of extraequatorial mechanisms modulating decadal sea surface temperature anomalies (SSTA) in the equatorial Atlantic is investigated using a suite of sensitivity experiments based on an ocean general circulation model. The model is forced by observed wind stress and/or computed heat flux from an associated advective atmospheric mixed layer model. In addition, the surface forcing is optionally applied on the equator or in off‐equatorial regions. The long‐term response of equatorial SST is dominated by local forcing. However, a weak but significant part of the response that is not in phase with the locally induced SST variability is caused by remote forcing. Subtropical cells (STCs) provide the oceanic bridging of the climate signals. The dynamical forcing leads to a spin‐up and spin‐down of the shallow cells, which, in the case of local forcing included, coincides with cold and warm SSTA. The local heat flux forcing reveals an overall damping tendency on the dynamical SST response. When excluding the local forcing, the isolation of the effect of the northern remote forcing from the one in the south appears to be essential in understanding the respective mechanisms at work. In the Northern Hemisphere, the spin‐up and spin‐down of the STC is highly correlated with the (lagging) SSTA, and the effect of off‐equatorial heat flux forcing on SSTA is negligible. In the Southern Hemisphere, both momentum and heat fluxes in the subtropics lead to a significant SST response on the equator.
Numerical computation of incomplete Lipschitz‐Hankel integrals of the Hankel type for complex‐valued arguments
Authors: Zhu Zhaohui , Dvorak Steven L. , Heckmann David L. , Prince John L.
Published: December 2005

Incomplete Lipschitz‐Hankel integrals (ILHIs) form an important class of special functions since they appear in numerous applications in engineering and physics. While ILHIs of the Hankel type can be expressed as linear combinations of ILHIs of the Bessel and Neumann types, this procedure can lead to computational inaccuracies. As shown in this paper, these inaccuracies can be avoided by directly computing ILHIs of the Hankel types (both the first and second kinds). If desired, these results can then be combined to obtain accurate values for the ILHIs of the Bessel and Neumann types. Series representations for complementary incomplete Lipschitz‐Hankel integrals (CILHIs) are also derived in this paper. CILHIs are often needed to avoid numerical inaccuracies caused by finite precision arithmetic. In order to better understand this group of special functions, the characteristics of ILHIs and CILHIs of the Hankel type are also discussed.
A continuous record of Florida Current temperature transport at 27°N
Authors: Shoosmith D. R. , Baringer M. O. , Johns W. E.
Published: December 2005

As part of a newly funded international program to monitor ocean heat transport at mid‐latitudes in the North Atlantic, a continuous estimate of the temperature transport of the Florida Current is required. Since 1982, volume transports have been inferred from voltage measurements monitored by submarine telephone cables across the Straits of Florida. Electromagnetic induction theory suggests that the cable voltage should actually give a more direct measure of conductivity transport than pure volume transport. Due to the strong dependence of conductivity on temperature, this would in theory result in a direct and continuous estimate of the Florida Current temperature transport. This hypothesis is investigated using data from a large number of temperature and velocity sections (58) across the Florida Current at the cable location, leading to a new calibration of the voltage signal for the temperature transport of the Florida Current, crucial for trans‐basin heat flux estimates.
Multidecadal North Atlantic climate variability and its effect on North American salmon abundance
Authors: Condron Alan , DeConto Robert , Bradley Raymond S. , Juanes Francis
Published: December 2005

Climate variability is now known to play a key role in the abundance of marine fisheries, and must be accounted for to implement sustainable management strategies. We show that North American Atlantic salmon abundance has fluctuated in parallel with the Atlantic Multidecadal Oscillation (AMO); a basin‐wide, low frequency climate mode producing cold‐warm‐cold sea surface temperatures over the last century. During the AMO warm (cool) phase salmon abundance is lower (higher). Changes in sea surface temperature associated with the AMO are most pronounced in the winter season near the Grand Banks of Newfoundland, a known overwintering area for salmon and an important time for determining survival. A moratorium on salmon fishing was established in 1992, but has so far contributed few signs of improvement in stock size. This may be explained by a shift in the AMO to a positive phase, producing persistently warm temperatures in the marine environment. Our findings show that a continued warming near the Grand Banks of Newfoundland will have a detrimental impact on this already depleted stock despite the reduction in commercial fishing.
Freshening of the Adélie Land Bottom Water near 140°E
Authors: Aoki Shigeru , Rintoul Stephen R. , Ushio Shuki , Watanabe Shuichi , Bindoff Nathaniel L.
Published: December 2005

Repeat summer hydrographic observations along 140°E are used to document significant changes in the properties of the Adélie Land Bottom Water (ALBW) between the mid‐1990s and 2002–2003. Water on the 28.35 kg·m−3 neutral density surface cooled by 0.2°C and freshened by 0.03 psu between 1994 and 2002. By re‐occupying the same stations in the same season, the effects of seasonal variability and spatial variability were minimised allowing the signal of water mass changes to be clearly identified. Comparison of the recent data to high quality historical observations shows that the ALBW also freshened between the late 1960s and the mid‐1990s. Although there is insufficient data to construct a continuous time series, the simplest explanation of the observed changes is that there has been a long‐term (>30 year) and continuing freshening of the source waters supplying bottom water to the Australian‐Antarctic basin.
ICESat measurements reveal complex pattern of elevation changes on Siple Coast ice streams, Antarctica
Authors: Csatho B. , Ahn Y. , Yoon T. , van der Veen C. J. , Vogel S. , Hamilton G. , Morse D. , Smith B. , Spikes V. B.
Published: December 2005

We compare ICESat data (2003–2004) to airborne laser altimetry data (1997–98 and 1999–2000) to monitor surface changes over portions of Van der Veen (VdVIS), Whillans (WIS) and Kamb ice streams (KIS) in the Ross Embayment of the West Antarctic Ice Sheet. The spatial pattern of detected surface changes is generally consistent with earlier observations. However, important changes have occurred during the past decade. For example, areas on the VdVIS and WIS, where large thinning was detected by the airborne surveys, are now closer to being in balance. The upper trunk of KIS continues to build up with thickening rates reaching 0.4 m/year. Our results provide new evidence that the overall mass balance of the region is becoming more positive, but a significant spatial variability exists. They also demonstrate the potential of ICESat data for detecting spatial patterns of surface elevation change in Antarctica.
An Atlantic blanket bog is a modest CO2 sink
Authors: Sottocornola Matteo , Kiely Ger
Published: December 2005

Northern peatlands contain 1/3 of the world's soil carbon pool. Blanket bogs are peatlands that occur in maritime regions where precipitation is much greater than evapotranspiration. The role of blanket bogs in C dynamics has not been quantified. We describe an investigation of CO2 fluxes using an eddy covariance (EC) system in a pristine Atlantic blanket bog in Ireland during 2003 and 2004. This is the first multiyear study using EC techniques in a blanket bog. We found that the bog ecosystem was a CO2 sink for five months in each year. The annual CO2 flux had a sink magnitude of −49 (2003) and −61 g C m−2 (2004). These magnitudes are similar to boreal raised bogs, while higher values have been reported for boreal fens and lower for subarctic fens.
Monitoring the high‐altitude cusp with the Low Energy Neutral Atom imager: Simultaneous observations from IMAGE and Polar
Authors: Taguchi S. , Chen S.‐H. , Collier M. R. , Moore T. E. , Fok M.‐C. , Hosokawa K. , Nakao A.
Published: December 2005

The Low Energy Neutral Atom (LENA) imager on the IMAGE spacecraft in the dayside magnetosphere can detect neutral particles that are emitted in the magnetosheath flow. During a period of dynamic pressure of 4–6 nPa and interplanetary magnetic field (IMF) Bz of −5 to 3 nT on 12 April 2001, LENA on IMAGE at (XGSM, YGSM, ZGSM) ∼ (4 RE, 0 RE, 6 RE) observed significant emission in the direction of the high‐latitude magnetosheath. Detailed analyses have revealed that the high‐latitude sheath emission consists of two parts: the stable emission at the higher latitudes and the lower‐latitude emission that occurs on and off. During the interval of this event, the Polar spacecraft was located at somewhat lower latitudes than IMAGE in similar noon meridian, and the plasma observations with the Thermal Ions Dynamic Experiment showed that the entry of the cusp ions happens in concurrence with the appearance of the lower‐latitude LENA emission. This coincidence strongly suggests that the cusp ions flowing earthward charge exchange with the hydrogen exosphere. For the higher‐latitude emission, its stability suggests that the source is associated with the structure persistently existing, which is consistent with the recent result showing that the sheath flow in the cusp indentation can create neutral atom emissions. Comparison of the LENA emission and ACE solar wind suggests that the lower‐latitude LENA emission occurs during the southward tilting of dawnward IMF, indicating that this emission is associated with the earthward ion flux along the newly reconnected field lines. Hence this unique event for the simultaneous observations strongly suggests that LENA monitors the entry of the ions in the cusp, which is triggered by the southward tilting of the IMF, and that the significant flux of the cusp ion entry occurs equatorward of and separately from the cusp indentation.
Spatial variations of magnetic susceptibility of Chinese loess for the last 600 kyr: Implications for monsoon evolution
Authors: Hao Qingzhen , Guo Zhengtang
Published: December 2005

We examine spatial variations in magnetic susceptibility (MS) over the Loess Plateau in China based on 50 sections in order to identify spatial changes in monsoon climate at key glacial, interglacial, and interstadial intervals for the last 600 kyr. The results indicate strong coherence between MS variations during the interglacial periods and present‐day precipitation and temperature patterns. This suggests that the strength of the summer monsoon had a dominant influence on the MS signals in soils, through modulating pedogenic intensity. The distribution of MS during glacial periods is characterized by weak S‐N gradients and rough W‐E zonal patterns, indicating a negligible effect of the summer monsoon. Interstadial patterns are intermediate between the glacial and interglacial ones. Interglacial patterns for the last 600 kyr are essentially similar, suggesting that the climate regime during these periods has not undergone significant changes and that the east Asian summer monsoon has remained the main moisture carrier. Our estimates of the relative amplitudes of climate oscillations during these time slices are consistent with earlier paleoclimate studies. These data, associated with the available susceptibility‐based climofunctions, may be used to estimate spatial changes of paleorainfall and paleotemperature for these key periods and hence to test climate models.
Spectral observations and modeling of the Arctic surface radiation environment
Authors: Kancler Erik , Gautier Catherine , Ricchiazzi Paul , Yang Shiren , Pilewskie Peter
Published: December 2005

Measurements from three spectral instruments, the Solar Spectral Flux Radiometer (SSFR), the Rotating Shadowband Spectrometer (RSS), and the Solar Ultraviolet Spectroradiometer (SUV), are compared to results from the Santa Barbara Moderate Resolution Radiative Transfer Model (SBMOD). SSFR data are from the SHEBA experiment of May–June 1998. RSS and SUV data are from Barrow, Alaska, April 1999. SBMOD is a recently developed model utilizing the correlated‐k method of computing gaseous absorption and convolves the solar source function and the instrument's filter function during computations. Comparisons indicate that absorption of ozone, water vapor, oxygen, and the O2‐O2 absorption complexes are well characterized by the model. There does not appear to be any significant unexplained absorption between 0.4 and 1.0 microns, as evidenced by comparisons between SBMOD and both SSFR and RSS data. However, a more absorptive aerosol was required to reach agreement between SBMOD and RSS diffuse fields than we anticipated. Data from the RSS and SUV possess similar structure over their entire shared spectral range from 400 to 600 nm, and the RSS and SSFR possess similar structure between 500 and 1000 nm. However, below 500 nanometers, measurements from all three instruments diverge noticeably from model results. The residual between the SUV and RSS measurements and SBMOD are similar to those presented in prior studies, suggesting that there may be errors in several widely used representations of the solar spectrum between 400 and 500 nm. The shape of the SSFR's data in this region has yet to be fully explained; aspects of its calibration and operation may be the main source of uncertainty.