bluuebunny/crossref_metadata_2025 huggingface dataset:
Amino acid uptake regulation by cell growth in cultured hepatocytes isolated from fetal and adult rats
Authors: Leoni S. , Spagnuolo S. , Massimi M. , Terenzi F. , Conti Devirgiliis L.
Published: March 2006

Amino acid uptake mediated by system A was studied in cultured fetal and adult hepatocytes, subjected to growth stimulation by EGF and insulin, or to growth inhibition by high cell density.

The mitogenic stimulation induced a strong transport increase only in fetal cells, while the cell density-dependent growth inhibition, probably mediated by molecules present on adult hepatocyte membranes, provoked the decrease of amino acid uptake only in the adult cells.

The results indicate that the different modulation of amino acid transport by cell growth is dependent on the age and the differentiation stage of hepatocytes.
Isolated Adrenal Metastasis: The Role of Laparoscopic Surgery
Authors: Sebag F. , Calzolari F. , Harding J. , Sierra M. , Palazzo F. F. , Henry J. F.
Published: March 2006

Background

Solitary adrenal metastases (AM) are rare and their management unclear. Surgery, especially laparoscopic adrenalectomy (LA), is debatable in the management of AM. This retrospective study analysed the feasibility and the results of LA for AM.

Methods

From 1997 to 2003, 16 patients underwent LA for isolated AM. Completeness of resection, postoperative morbidity and follow‐up (FU) were recorded.

Results

There were 10 synchronous AM and 6 metachronous AM. Primary tumours included lung cancer (n = 9), melanoma (n = 3), mesothelioma (n = 1), rhabdomyosarcoma (n = 1), colonic adenocarcinoma (n = 1) and renal cell carcinoma (n = 1). Five patients required conversion to an open procedure. Minor complications occurred in three patients. Pathology confirmed the diagnosis of AM. Mean tumour size was 60 (range: 15–110) mm. Nine patients (56%) had complete resections, 3 had positive margins and 4 had incomplete macroscopic resections. Mean observed FU was 25 (range: 1–68) months. Median overall calculated survival was 23 months. Overall 5‐year survival was 33% (Kaplan–Meyer). At the end of study, 8 patients were alive with a mean FU of 35 months (3 without evidence of disease). No patient presented with local relapse or port‐site metastasis. We did not identify any predictive factors. All patients with incomplete macroscopic resection died within 24 months.

Conclusions

LA can achieve an acceptable 5‐year survival, comparable to open surgery but with better postoperative comfort. It should be considered for AM with the intention of complete resection. It offers the patient the possibility of tumour resection with the benefit of a laparoscopic approach.
Ecosystem services and their values: a case study in the Qinba mountains of China
Authors: Li Jing , Ren Zhiyuan , Zhou Zixiang
Published: March 2006

Terrestrial ecosystem services can provide both direct and indirect economic benefits. In this case study, we estimated the annual economic value of some ecosystem services provided by terrestrial ecosystems in the Qinba mountains of Shaanxi Province of China, using both simulation models and a geographic information system that helps to analyze the effect of ecological factors on ecosystem functions. With respect to differences in vegetation types and their coverage, by combining the latest research, and using theory and methods for the value of terrestrial ecosystem services, we not only calculated goods produced by different types of vegetation but also estimated the value of various terrestrial ecosystem services. We also set up a database and an eco‐account of a terrestrial ecosystem. The ecosystem services assessed relate to the following aspects: the vegetation's primary productivity, soil and fertility conservation, water conservation, carbon fixation and oxygen supply. The total economic value of terrestrial ecosystem services in the Qinba mountains was estimated to be 968.33 billion renminbi per year, and represents a part of the actual ecosystem services. In addition, we analyzed the spatial distribution of the vegetation based on the economic values of the terrestrial ecosystem services. Our findings can contribute to the conservation of these terrestrial ecosystems and the effective use of these ecosystem services.
Learning to live in a global commons: socioeconomic challenges for a sustainable environment
Authors: Levin Simon A.
Published: March 2006

Ecologists, economists and other social scientists have much incentive for interaction. First of all, ecological systems and socioeconomic systems are linked in their dynamics, and these linkages are key to coupling environmental protection and economic growth. Beyond this, however, are the obvious similarities in how ecological systems and socioeconomic systems function, and the common theoretical challenges in understanding their dynamics. This should not be surprising. Socioeconomic systems are in fact ecological systems, in which the familiar ecological phenomena of exploitation, cooperation and parasitism all can be identified as key features. Or, viewed from the opposite perspective, ecological systems are economic systems, in which competition for resources is key, and in which an evolutionary process shapes the individual agents to a distribution of specialization of function that leads to the emergence of flows and functionalities at higher levels of organization. Most fundamentally, ecological and socioeconomic systems alike are complex adaptive systems, in which patterns at the macroscopic level emerge from interactions and selection mechanisms mediated at many levels of organization, from individual agents to collectives to whole systems and even above. In such complex adaptive systems, robustness must be understood as emergent from selection processes operating at these many different levels, and the inherent nonlinearities can trigger sudden shifts in regimes that, in the case of the biosphere, can have major consequences for humanity. This lecture will explore the complex adaptive nature of ecosystems, and the implications for the robustness of ecosystem services on which we depend, and in particular examine the conditions under which cooperative behavior emerges. It will then turn attention to the socioeconomic systems in which environmental management is based, and ask what lessons can be learned from our examination of natural systems, and how we can modify social norms to achieve global cooperation in managing our common future. Of special interest will be issues of intragenerational and intergenerational equity, and the importance of various forms of discounting.
Hepatic guanylate cyclase activity is decreased in a model of cirrhosis: A quantitative cytochemistry study
Authors: Davies Nathan A. , Hodges Stephen J. , Pitsillides Andrew A. , Mookerjee Rajeshwar P. , Jalan Rajiv , Mehdizadeh Siroos
Published: March 2006

The production of nitric oxide (NO) in liver disease and its role in vascular control has been a subject of much interest in recent years. However, the activity of guanylate cyclase (GC), the enzyme activated by NO has received little attention with regard to liver disease. In this study we have utilised a quantitative cytochemical technique to examine the activity of GC on a per cell basis in a rat model of cirrhosis. Our results show a significant reduction in GC activity, indicating that vascular regulation is likely to be substantially affected irrespective of NO generation in this disease model.
Mechanisms of signal transduction in photo‐stimulated secretion in Phaeocystis globosa
Authors: Quesada Ivan , Chin Wei-Chun , Verdugo Pedro
Published: March 2006

Phaeocystis globosa, a leading agent in marine carbon cycling, releases its photosynthesized biopolymers via regulated exocytosis. Release is elicited by blue light and relayed by a characteristic cytosolic Ca2+ signal. However, the source of Ca2+ in these cells has not been established. The present studies indicate that Phaeocystis’ secretory granules work as an intracellular Ca2+ oscillator. Optical tomography reveals that photo‐stimulation induces InsP3‐triggered periodic lumenal [Ca2+] oscillations in the granule and corresponding out‐of‐phase cytosolic oscillations of [Ca2+] that trigger exocytosis. This Ca2+ dynamics results from an interplay between the intragranular polyanionic matrix, and two Ca2+‐sensitive ion channels located on the granule membrane: an InsP3‐receptor‐Ca2+ channel, and an apamin‐sensitive K+ channel.
Fusogenic potential of sperm membrane lipids: Nature's wisdom to accomplish targeted gene delivery
Authors: Atif Shaikh Muhammad , Hasan Imtaiyaz , Ahmad Nadeem , Khan Umber , Owais Mohammad
Published: March 2006

The membrane–membrane fusion during fertilization of oocyte by spermatozoa is believed to be mainly mediated by so called “fusion proteins”. In the present study we have tried to demonstrate that beside the proteins, lipid components of membrane may play an important role in fusion of oocyte with spermatozoa. Conventional membrane–membrane fusion assays were used as means to demonstrate fusogenic potential of human sperm membrane lipids. The liposomes (spermatosomes) made of the lipids isolated from sperm membrane were found to undergo strong membrane–membrane fusion as evident from fluorescence dequenching and resonance energy transfer assays. Furthermore, the fusion of these liposomes with living cells (J774 A.1 macrophage cell line) was demonstrated to result in an effective transfer of a water‐soluble fluorescent probe (calcein) to cytosol of the target cell. Lastly, the liposomes were demonstrated to behave like efficient vehicles for the in vivo cytosolic delivery of the antigens to target cells resulting in elicitation of antigen specific CD8+ T cell responses.
Soluble cytochrome c‐554, CycA, is not essential for photosynthetic electron transfer in Chlorobium tepidum
Authors: Tsukatani Yusuke , Miyamoto Ryo , Itoh Shigeru , Oh-oka Hirozo
Published: March 2006

We constructed a mutant lacking soluble cytochrome c‐554 (CycA) by disruption of the cycA gene in the green sulfur bacterium Chlorobium tepidum. The mutant grew phototrophically with a growth rate slower than that of the wild type, suggesting that CycA is not essential for photosynthetic electron transfer even though CycA is known to work as an electron donor to the reaction center. The re‐reduction of photo‐oxidized cytochrome c
z by quinol oxidoreductase was inhibited almost completely by the addition of stigmatellin in the mutant cells. This result indicates that, in the mutant cells, the linear electron transfer can occur from the quinol oxidoreductase to cytochrome c
z, and to reaction center P840 with no participation of CycA.
α‐Synuclein facilitates the toxicity of oxidized catechol metabolites: Implications for selective neurodegeneration in Parkinson's disease
Authors: Hasegawa Takafumi , Matsuzaki-Kobayashi Michiko , Takeda Atsushi , Sugeno Naoto , Kikuchi Akio , Furukawa Katsutoshi , Perry George , Smith Mark A. , Itoyama Yasuto
Published: March 2006

Free radicals, including dopamine (DA)‐oxidized metabolites, have long been implicated in pathogenesis of Parkinson's disease (PD). However, the relationships between such oxidative stresses and α‐synuclein (α‐S), a major constituent of Lewy bodies, remain unknown. In this study, we established neuronal cells that constitutively express α‐S and tetracycline‐regulated tyrosinase. While tyrosinase overexpression induced apoptosis, co‐expression of wild type or A53T mutant human α‐S with tyrosinase further exacerbated cell death. In this process, the formation of α‐S oligomers and the reduction in mitochondrial membrane potential were demonstrated. This cellular model may reconstitute the pathological metabolism of α‐S in the synucleinopathy and provide a useful tool to explore possible pathomechanisms of nigral degeneration in PD.
Phosphoinositide‐dependent kinase l (PDK1) haplo‐insufficiency inhibits production of alpha/beta (α/β) but not gamma delta (γ/δ) T lymphocytes
Authors: Kelly April P. , Hinton Heather J. , Clarke Rosemary G. , Cantrell Doreen A.
Published: March 2006

In the present study, we have explored the impact of deleting a single allele of PDK1 in T cell progenitors on α/β and γ/δ T cell development. The data show that deleting a single allele of PDK1 allows differentiation of α/β T cells but prevents their proliferative expansion in the thymus. Accordingly, mice with T cells that are haplo‐insufficient for PDK1 have reduced numbers of thymocytes and α/β peripheral T cells. T cell progenitors also give rise to γ/δ T cells but in contrast to the loss of α/β T cells in T‐PDK1 null and haplo‐insufficient mice, there were increased numbers of γ/δ T cells. The production of α/β T cells is dependent on the proliferative expansion of thymocytes and is determined by a balance between the frequency with which cells enter the proliferative phase of the cell cycle and rates of cell death. Herein, we show that PDK1 haplo‐insufficient thymocytes have no defects in their ability to enter the cell cycle but show increased apoptosis. PDK1 thus plays a determining role in the development of α/β T lymphocytes but does not limit γ/δ T cell development.
Relationships between wave exposure and biomass of the goose barnacle (Pollicipes pollicipes, Gmelin, 1790) in the Gaztelugatxe Marine Reserve (Basque Country, northern Spain)
Authors: Borja Ángel , Liria Pedro , Muxika Iñigo , Bald Juan
Published: March 2006

Marine protected areas play an important role in the conservation of marine resources and fisheries management. In the Basque Country (northern Spain), the small (158 ha) Gaztelugatxe Marine Reserve was established in 1998; after 5 years without exploitation, it is considered likely that the goose barnacle Pollicipes pollicipes populations have recovered. This contribution provides information on the standing stock, and of the relationships between biomass, coverage, and density, and environmental factors such as wave height and energy derived from waves received at the coast. Increasing energy levels produce enhanced coverage and abundance, providing a bigger standing stock in the reserve. Numerical models to simulate the energy produced by waves can be used as a tool to predict the potential biomass of the goose barnacle along the coast. Such an approach allows comparison of observed and predicted biomasses, and possibly also determination of the factors involved in the observed differences, e.g. overexploitation and pollution; this will assist in assessing goose barnacle resources along the coast.
Proterozoic mountain building in Peninsular India: an analysis based primarily on alkaline rock distribution
Authors: LEELANANDAM C. , BURKE K. , ASHWAL L. D. , WEBB S. J.
Published: March 2006

Peninsular India was assembled into a continental block c. 3 million km2 in area as a result of collisions throughout the length of a 4000 km long S-shaped mountain belt that was first recognized from the continuity of strike of highly deformed Proterozoic granulites and gneisses. More recently the recognition of a variety of tectonic indicators, including occurrences of ophiolitic slivers, Andean-margin type rocks, a collisional rift and a foreland basin, as well as many structural and isotopic age studies have helped to clarify the history of this Great Indian Proterozoic Fold Belt. We here complement those studies by considering the occurrence of deformed alkaline rocks and carbonatites (DARCs) in the Great Indian Proterozoic Fold Belt. One aim of this study is to test the recently published idea that DARCs result from the deformation of alkaline rocks and carbonatites (ARCs) originally intruded into intra-continental rifts and preserved on rifted continental margins. The suggestion is that ARCs from those margins are transformed into DARCs during continental, or arc–continental, collisions. If that idea is valid, DARCs lie on rifted continental margins and on coincident younger suture zones; they occur in places where ancient oceans have both opened and closed. Locating sutures within mountain belts has often proved difficult and has sometimes been controversial. If the new idea is valid, DARC distributions may help to reduce controversy. This paper concentrates on the Eastern Ghats Mobile Belt of Andhra Pradesh and Orissa, where alkaline rock occurrences are best known. Less complete information from Kerala, Tamil Nadu, Karnataka, West Bengal, Bihar and Rajasthan has enabled us to define a line of 47 unevenly distributed DARCs with individual outcrop lengths of between 30 m and 30 km that extends along the full 4000 km length of the Great Indian Proterozoic Fold Belt. Ocean opening along the rifted margins of the Archaean cratons of Peninsular India may have begun by c. 2.0 Ga and convergent plate margin phenomena have left records within the Great Indian Proterozoic Fold Belt and on the neighbouring cratons starting at c. 1.8 Ga. Final continental collisions were over by 0.55 Ga, perhaps having been completed at c. 0.75 Ga or at c. 1 Ga. Opening of an ocean at the Himalayan margin of India by c. 0.55 Ga removed an unknown length of the Great Indian Proterozoic Fold Belt. In the southernmost part of the Indian peninsula, a line of DARCs, interpreted here as marking a Great Indian Proterozoic Fold Belt suture, can be traced within the Southern Granulite Terrain almost to the Achankovil-Tenmala shear zone, which is interpreted as a strike-slip fault that also formed at c. 0.55 Ga.
CHRONICLES: (January 1, 2004––December 31, 2004)
Authors: Siehr Kurt G.
Published: March 2006

Chronicles: January 1, 2004––December 31, 2004.
Canwick (Lincolnshire) and Melbourn (Cambridgeshire) in Comparative Perspective within the Open-Closed Village Model
Authors: MILLS DENNIS
Published: March 2006

Canwick Hall, near Lincoln, was the seat of the Sibthorps from 1730 to 1940. They represented the city in Parliament over several generations. The evolution of their estate village is seen here in contrast to the open village of Melbourn, in the context of the open-closed village model, and in comparison with two other estates of similar size and value (the Sneyds' estate at Keele, Staffordshire and the Fawkeses' estate at Farnley in Wharfedale). The Sibthorps were a ten thousand-acre and ten thousand pounds-a-year family for most of the nineteenth century, but the amount of attention they paid to Canwick varied considerably, depending on the individual circumstances and preferences of a succession of life-tenants.
Mechanisation and Society in English Agriculture: The Experience of the North-East, 1850–1914
Authors: CAUNCE S. A.
Published: March 2006

This article examines three linked assumptions relating to English agriculture between 1850 and 1914. First, that the north devoted its energies to industrialisation. Second, that mechanisation made steady progress, based largely on southern initiatives. Third, that this took farming towards large, capital-intensive and steam-powered operations. This conventional wisdom is inherently weak given the high reputation of Northumbrian farming in 1850, its tight, expensive labour markets and easy access to coal, iron and engineering expertise, which contrasts with the south's cheap, plentiful labour, no coal and few engineering firms. A database of all implements advertised in a thousand farm sales from the relevant period in Northumberland, Durham and northern North Yorkshire reveals a regional agriculture that prospered by developing the traditional and highly effective mix of carts, harrows and ploughs. Mechanisation occurred very unevenly across departments, with harvesting very atypical. Large farms were neither more inherently machine-oriented than small ones, nor better users of machinery. Farmers are revealed as pragmatic about mechanisation, and not conservative when it paid. Steam played little part, whereas horses remained an ideal power source for the farming that suited these times.
The Rationalisation of Rural Sport: British Sheepdog Trials, 1873–1946
Authors: URDANK ALBION M.
Published: March 2006

The article analyses the evolution in both the forms and changing social content of British Sheepdog trials, from the first recorded event at Bala, Wales in 1873 to the advent of their revival following the Second World War (during which they had been suspended). Contrary to popular myth, early trials were gentry sponsored and therefore heavily freighted with elite values concerning the nature of the shepherds' craft. Early trials accented speed, agility and obedience in the dog, as well as sheer entertainment value, arising often from debacles that might ensue in any given run. The trials, too, remained adjuncts to elite, Kennel-club style dog-shows, with their focus on conformation and the physical beauty of the animal. As the social prominence of the aristocracy and gentry receded after 1880, so too did their role in defining the nature of the sheepdog trial. With the founding of the International Sheepdog Society in 1906 by shepherds and farmers, the rules for such trials became transformed, reflecting more the actual work of the shepherd, and indirectly the larger shift within agriculture toward more specialised sheep production. These new rules gave the trial a rigorous aspect at once more modern than earlier prototypes, yet rooted in the craft traditions of rural artisans. At the same time, the shepherds and farmers, who made practical use of sheepdogs, assumed direction of the sport. The founding of the ISDS thus coincided with the new self-assertiveness of labour occurring nationally, reflected in the founding of the Labour party the very same year. Elements of the elite show-ring, however, would linger residually in ISDS trials, reflecting a degree of continuity, but these would gradually atrophy. ISDS trials would accent both the independent work of the dog and its ability to function as a working partner to the shepherd. The article thus deconstructs the complicated social evolution in the nature of a rural sport, which reflected in turn changes in the larger socio-economic environment, through a detailed analysis of the changing patterns of the trials themselves.
Congenital and acquired bleeding problems in elderly patients
Authors: Nicolle AL , Talks KL , Hanley JP
Published: March 2006

Bleeding in elderly patients is most commonly due to an underlying structural problem or an acquired coagulopathy. Occasionally, previously asymptomatic congenital bleeding disorders may present at an advanced age. When considering the possible causes of a clinical bleeding problem, the coagulation cascade is still a good starting-point. However, it is important to realize that the traditional model of the coagulation cascade has been superceded by the concept of a ‘coagulation network’. This updated model recognizes the importance of tissue factor in the initiation of coagulation. Despite the complexity of this model, the basic coagulation tests can still be interpreted in relation to the ‘intrinsic’, ‘extrinsic’ and ‘final common pathway’ components of the old-fashioned cascade (Figure 1).
Dissolved iron in the tropical and subtropical Atlantic Ocean
Authors: Bergquist B. A. , Boyle E. A.
Published: March 2006

Detailed depth profiles and surface transects of dissolved iron (DFe defined by 0.4‐μm filtration) were investigated on three cruises in the subtropical and tropical Atlantic Ocean where dust deposition varied by 3 orders of magnitude. Surface DFe and dissolved Mn concentrations reflected dust deposition trends, but are not proportional to the estimated inputs. Using estimates of the atmospheric flux of DFe, surface DFe residence times were calculated to be on the order of 1 to 5 months. Deepwater DFe concentrations varied with water masses depending on their source, age, and transit pathways. At a site located on the edge of the equatorial system (10°N, 45°W), high DFe (>1 nmol/kg) was associated with an oxygen minimum zone at depths of 130 to 1100 m. DFe concentrations in North Atlantic Deep Water (NADW) decreased by 30% from sites in the North Atlantic to a site in the South Atlantic (24.5°S, 37°W), and DFe was lower in the Antarctic derived water masses (∼0.4 nmol/kg) than in NADW at the South Atlantic site. An estimate of deepwater scavenging residence time for DFe was 270 ± 140 years based on decreasing DFe along the NADW flow path.
Influence of stratospheric sudden warming on the equatorial troposphere
Authors: Kodera Kunihiko
Published: March 2006

A circulation change related to stratospheric sudden warming was investigated to examine the role of the stratosphere in equatorial tropospheric convective activity. A composite analysis of twelve stratospheric warmings from 1979 to 2001 revealed that the meridional circulation change associated with stratospheric warming in the polar region produces a lower temperature in the equatorial lower stratosphere and upper troposphere, which leads to a seesaw of convective activity in the troposphere – an enhancement of convective activity near the equatorial southern hemisphere (10°S‐equator) but a suppression in the tropics of the northern hemisphere (5°N–15°N).
Electrostatic solitary structures observed at Saturn
Authors: Williams J. D. , Chen L.‐J. , Kurth W. S. , Gurnett D. A. , Dougherty M. K.
Published: March 2006

We report observations of electric field solitary structures, measured by the Cassini Radio and Plasma Wave Science (RPWS) instrument in the vicinity of Saturn's magnetosphere with ambient magnetic fields that range from ∼0.1 nT to 8000 nT. The peak‐to‐peak electric field amplitudes of the observed solitary structures range from a few μV/m to 10 mV/m and show a slight trend toward larger amplitude electric field pulses being associated with larger ambient magnetic fields. The time durations of the pulses range from a few hundred μs to a few 10's of milliseconds. The solitary waves appear in plasma boundary regions or in regions with abrupt changes in the magnetic field. The solitary waves tend to be observed when the dipole antenna is aligned with the magnetic field.
Proton auroral intensifications and injections at synchronous altitude
Authors: Chi Eric C. , Mende Stephen B. , Fok M.‐C. , Reeves G. D.
Published: March 2006

In sudden flux increases at synchronous altitude the lower energy channels often show progressively more delay or dispersion. It is usually assumed that the dispersion is caused by a simultaneous injection of particles of all energies at some location, and by the subsequent drift of these particles to the synchronous altitude measurement site “downstream” of the injection event. In this paper we present a method for timing and locating the injections from proton auroral precipitation inferred by the Lyman α emission data from the IMAGE FUV instrument. We compare the timing of the proton flux increases observed by the Los Alamos National Laboratory synchronous altitude satellites to the time delay predicted by a model describing the longitudinal drift of particles in the magnetosphere. We present comparisons for eleven substorm particle injections and find that the observed azimuthal drift times are reasonably consistent with those calculated by a simple model using the Tsyganenko 89 magnetic and Volland electric field models as input. This consistency supports the concept that the proton auroral intensification at substorm onset and the proton injection in the magnetosphere occur at the same magnetic local time (longitude).
On the relevance of Born theory in global seismic tomography
Authors: Boschi Lapo , Becker Thorsten W. , Soldati Gaia , Dziewonski Adam M.
Published: March 2006

Does the application of seismic Born theory, as opposed to simpler ray theory, lead to an improvement in tomographic images of the Earth? In recent publications, Montelli et al. (2004a, 2004b) and van der Hilst and de Hoop (2005) among others have expressed opposite opinions. We propose a quantitative approach to the comparison of tomographic images, which we apply to the case of surface‐wave phase velocity maps derived with Born vs. ray theory.
On the velocity distributions of dust‐related inner‐source pickup ions
Authors: Bochsler P. , Möbius E. , Wimmer‐Schweingruber R. F.
Published: March 2006

We simulate velocity distributions for inner‐source pickup ions in two scenarios for their origin. One scenario creates inner‐source pickup ions by charge exchange and energy loss in very small (typically submicron‐sized) dust grains (Wimmer‐Schweingruber and Bochsler 2003), while the other liberates solar wind ions previously implanted in larger (typically 1 μm) dust grains (Geiss et al. 1995; and Gloeckler and Geiss 1998). The two scenarios differ by the initial velocity with which the pickup ions are created; the fine‐dust model produces a wide initial velocity distribution, while the coarse‐dust model releases them essentially at rest. We investigate the differences in the distributions once these ions have been transported out to an observer at 1 AU or beyond.
Ground surface paleotemperature reconstruction using information measures and empirical Bayes
Authors: Woodbury Allan D. , Ferguson Grant
Published: March 2006

We outline an empirical Bayesian approach to ground‐surface temperature (GST) reconstruction that utilizes Akaike's Bayesian information criterion (ABIC). Typical unknown statistical quantities, such as the noise variance and so on, are automatically determined through the analysis. We compare the ABIC inversion to the singular value decomposition on a synthetic downhole temperature data set. In comparing the root mean square errors between the synthetic climatic signal and each of the reconstructions (singular value and ABIC) from 1900 to 2002, we see that the ABIC solution produced the ‘best’ reconstruction in a mean square sense. We also carry out an analysis of the Canadian borehole data set in which we use 221 temperature profiles. The reconstructed GST record shows warming between 1800 and 1949 of approximately 1.0 K, with the maximum rate of warming occurring between 1900 and 1949.
Using multiple observationally‐based constraints to estimate climate sensitivity
Authors: Annan J. D. , Hargreaves J. C.
Published: March 2006

Climate sensitivity has been subjectively estimated to be likely to lie in the range of 1.5–4.5°C, and this uncertainty contributes a substantial part of the total uncertainty in climate change projections over the coming century. Objective observationally‐based estimates have so far failed to improve on this upper bound, with many estimates even suggesting a significant probability of climate sensitivity exceeding 6°C. In this paper, we show how it is possible to greatly reduce this uncertainty by using Bayes' Theorem to combine several independent lines of evidence. Based on some conservative assumptions regarding the value of independent estimates, we conclude that climate sensitivity is very unlikely (<5% probability) to exceed 4.5°C. We cannot assign a significant probability to climate sensitivity exceeding 6°C without making what appear to be wholly unrealistic exaggerations about the uncertainties involved. This represents a significant lowering of the previously‐estimated bound.
Variations in annual global precipitation (1979–2004), based on the Global Precipitation Climatology Project 2.5° analysis
Authors: Smith Thomas M. , Yin Xungang , Gruber Arnold
Published: March 2006

The Global Precipitation Climatology Project (GPCP) has produced a combined satellite and in situ global precipitation estimate, beginning 1979. The annual average GPCP estimates are here analyzed over 1979–2004 to evaluate the large‐scale variability over the period. Data inhomogeneities are evaluated and found to not be responsible for the major variations, including systematic changes over the period. Most variations are associated with El Niño/Southern Oscillation (ENSO) episodes. There are also tropical trend‐like changes over the period, correlated with interdecadal warming of the tropical SSTs and uncorrelated with ENSO. Trends have spatial variations with both positive and negative values, with a global‐average near zero.
Europa's FUV auroral tail on Jupiter
Authors: Grodent D. , Gérard J.‐C. , Gustin J. , Mauk B. H. , Connerney J. E. P. , Clarke J. T.
Published: March 2006

Ultraviolet images of Jupiter's northern aurora obtained in 2005 confirm the existence of an electromagnetic interaction between Europa and the Jovian ionosphere. The auroral signature shows a two‐component structure: a quasi‐circular Europa spot, followed by a previously undetected faint tail emission trailing in the direction of corotation flow. The characteristic brightness for the auroral spot is ∼14 ± 1 kR above background, and approximately 7 ± 1 kR for the tail. The spot's size is ∼1100 km, magnetically mapping to an interaction region ≤15 Europa diameters. The auroral tail extends over ∼5000 km, which maps along a region of at least 70 Europa diameters. The ultraviolet power emitted by both components varies from a fraction to several GW. The present study suggests auroral interaction at Europa similar to that at Io, but scaled‐down by an order of magnitude, including a sub‐corotating plasma plume in the geometrical wake of Europa.
Spatiotemporal scaling properties of the ground geomagnetic field variations
Authors: Pulkkinen Antti , Klimas Alex , Vassiliadis Dimitris , Uritsky Vadim , Tanskanen Eija
Published: March 2006

The spatiotemporal scaling properties of the auroral region ground horizontal magnetic field fluctuations are investigated in terms of structure function analysis. First, the distorting effects of the continuation of the magnetic field from the ionosphere to the ground level and the effects of the geomagnetic induction on the derived scalings are studied. It is found that the spatial fluctuations of the magnetic field and its time derivative are distorted by the field continuation in the ranges of scales of the data, i.e., 100 < Δr < 2400 km (above ∼1000 km, analysis is spatially one‐dimensional) and 10 < τ < 104 s. Specifically, the extent of the distortion is found to be dependent on the original ionospheric level scaling of the fluctuations. The effect of the geomagnetic induction is found to be negligible in the ranges of scales of the data. The main findings of the study are (1) there is a significant change in the dynamics of the field fluctuations in the range 80 < τ < 100 s where the time derivative of the magnetic field undergoes a transition from correlated to uncorrelated temporal behavior, (2) the spatiotemporal behavior of the time derivative of the magnetic field above temporal scales of 100 s resembles that of uncorrelated white noise, (3) the spatial symmetry of the field fluctuations increases during substorms, indicating the presence of spatially less ordered ionospheric equivalent currents, and (4) the spatial scaling properties of the field fluctuations may explain why the magnetotelluric sounding method works better than expected in auroral regions.
Effect of the acceleration current on the centrifugal interchange instability
Authors: Hill T. W.
Published: March 2006

The centrifugal interchange instability is the primary driver of radial plasma transport in the magnetospheres of Jupiter and Saturn. Most previous theoretical treatments of this instability have ignored the role of the acceleration current and have assumed that the divergence of the centrifugal drift current in the magnetosphere is closed by Pedersen currents in the underlying ionosphere, through the connection provided by Birkeland (magnetic‐field‐aligned) currents. This is a reasonable approximation when the radial transport speed is small compared with the rotation speed. However, the exponential growth of the instability inevitably leads to the eventual violation of this condition. I analyze a simplified model of the Io plasma torus to show that when the radial transport speed becomes comparable to the rotation speed, the acceleration current becomes the primary mechanism for closure (actually local cancellation) of the centrifugal drift current, and the connection to the planetary ionosphere therefore becomes irrelevant. An immediate consequence is that the growth rate of the instability does not exceed the planetary rotation rate.
Evaluation of continental precipitation in 20th century climate simulations: The utility of multimodel statistics
Authors: Phillips Thomas J. , Gleckler Peter J.
Published: March 2006

In support of the Intergovernmental Panel on Climate Change (IPCC), simulations of 20th century climate have been performed recently with some 20 global coupled ocean‐atmosphere models. In view of its central importance for biological and socioeconomic systems, model‐simulated continental precipitation is evaluated relative to three observational estimates at both global and regional scales. Many models are found to display systematic biases, deviating markedly from the observed spatial variability and amplitude/phase of the seasonal cycle. However, the pointwise ensemble mean of all the models usually shows better statistical agreement with the observations than does any single model. Deficiencies of current models that may be responsible for the simulated precipitation biases as well as possible reasons for the improved estimate afforded by the multimodel ensemble mean are discussed. Implications of these results for water resource managers also are briefly addressed.
A Unique Cactus with Scented and Possibly Bat‐Dispersed Fruits: Rhipsalis juengeri
Authors: Schlumpberger B. O. , Clery R. A. , Barthlott W.
Published: March 2006

Abstract: Rhipsalis juengeri was described in 1995 as an unusual representative of epiphytic cacti, forming more than 3 m long curtains, hanging from the canopy of the Atlantic Rainforest in eastern Brazil. At the apex of thin, pendant shoots, green‐brownish berries are formed. We report here as a novelty for the Cactaceae that these berries are strongly scented, and present an odour analysis along with an olfactoric survey of fruits of about 50 species and varieties of the cactus tribe Rhipsalideae. The volatile blend of berries of R. juengeri is dominated by ketones, some of which are responsible for the characteristic blackcurrant‐like scent, as is shown by GC‐olfactometry. The odour and inconspicuous colour stand out among fruits of other epiphytic cacti that are thought to be consumed by birds. Fruit characters of R. juengeri and the flagellicarpic presentation indicate adaptation to chiropterochory.
Genetic Diversity and Population Structure ofElytrigia pycnantha(Godr.) (Triticeae) in Mont Saint‐Michel Bay Using Microsatellite Markers
Authors: Refoufi A. , Esnault M.‐A.
Published: March 2006

Abstract:During the last decade, an invasive wheatgrass species(Elytrigia pycnantha)has colonized the low salt marshes of the Mont Saint Michel Bay resulting in an accelerated change in the vegetation. This study was conducted using microgeographical genetic diversity in order to understand the genetic structure of this invasive and clonal species. Genetic variation and population structure of fifteen populations collected in high and low marsh habitats around the Bay were analyzed using five microsatellite loci. BecauseE. pycnanthais an allohexaploid, the application of standard genetic diversity statistics was not possible, we chose to summarize genetic diversity using statistics calculated from banding phenotypes. The mean number of alleles per locus was 10.2, the mean number of different alleles per sample was 6.87. The mean number of allelic phenotypes across all populations was 7.21. The mean value of genetic diversity for the species, calculated as the average number of alleles by which pairs of individuals differ, was H′s = 1.91 and H′t = 2.04. Little genetic differentiation among populations was detected (0.067). The association between pairwise genetic differentiation and geographic distances exhibited no evidence for isolation by distance. A geographical pattern of population differentiation, where a single population GI was clearly separated from the remaining population groups (considered as a metapopulation), was revealed by principal component analysis (PCA), and we propose that this is because GI represents a new genotype.
Progress in Parasitic Plant Biology: Host Selection and Nutrient Transfer
Authors: Shen H. , Ye W. , Hong L. , Huang H. , Wang Z. , Deng X. , Yang Q. , Xu Z.
Published: March 2006

Abstract:Host range varies widely among species of parasitic plants. Parasitic plants realize host selection through induction by chemical molecular signals, including germination stimulants and haustoria‐inducing factors (HIFs). Research on parasitic plant biology has provided information on germination, haustorium induction, invasion, and haustorial structures and functions. To date, some molecular mechanisms have been suggested to explain how germination stimulants work, involving a chemical change caused by addition of a nucleophilic protein receptor, and direct or indirect stimulation of ethylene generation. Haustorium initiation is induced by HIFs that are generated by HIF‐releasing enzymes from the parasite or triggered by redox cycling between electrochemical states of the inducers. Haustorium attachment is non‐specific, however, the attachment to a host is facilitated by mucilaginous substances produced by haustorial hairs. Following the attachment, the intrusive cells of parasites penetrate host cells or push their way through the host epidermis and cortex between host cells, and some types of cell wall‐degrading enzymes may assist in the penetration process. After the establishment of host‐parasite associations, parasitic plants develop special morphological structures (haustoria) and physiological characteristics, such as high transpiration rates, high leaf conductance, and low water potentials in hemiparasites, for nutrient transfer and resource acquisition from their hosts. Therefore, they negatively affect the growth and development and even cause death of their hosts.
Finding and Understanding Reusable Designs from Large Hierarchical Repositories
Authors: Demian Peter , Fruchter Renate
Published: March 2006

This paper describes a prototype called CoMem (Corporate Memory) that supports the finding and understanding of useful items in large hierarchical repositories. The particular domain is civil engineering design, and the prototype is designed specifically to support design reuse in building construction projects. However, the underlying visualization and interaction principals behind CoMem are generalizable to the ubiquitous task of finding and understanding useful information in large hierarchical repositories. To support the finding, the entire hierarchy is visualized using a squarified treemap. Once an item from the treemap is selected, CoMem supports the understanding of that item by identifying related items in the hierarchy and visualizing the selected item in the context of these related items in a node-link diagram. The paper concludes with a brief discussion of a usability evaluation of CoMem that supports the claim that finding and understanding improve the process of reuse, and that the described visualizations assist with finding and understanding.
Quantum modeling of transient infrared spectra reflecting photoinduced electron-transfer dynamics
Authors: Strodel Birgit , Stock Gerhard
Published: March 2006

A theoretical description of transient vibrational spectra following the impulsive optical excitation of a molecular system is presented. The approach combines the nonsecular evaluation of the Redfield equations to describe the dissipative dynamics of the system with an efficient implementation of the doorway-window formalism to calculate optical pump/infrared probe (vis/IR) spectra. Both parts of the calculation scale with N2, thus facilitating the treatment of systems with a dimension up to 104. The formulation is applied to a simple model of photoinduced electron transfer, which takes into account two coupled electronic states and a single anharmonic vibrational mode. Despite its simplicity, the model is found to exhibit quite complex electronic and vibrational relaxation dynamics, which in turn give rise to rather complex time- and frequency-resolved vis/IR spectra. Interestingly, the calculated IR spectra of the electron-transfer system predict the appearance of novel vibronically induced sidebands, which may even dominate the spectrum at early times.
Development of a periscopic confocal microscope for in situ observation under high magnetic fields
Authors: Hirota Noriyuki , Ode Takahiro
Published: March 2006

This article contains a description of a periscope system developed for in situ high-resolution observation under high magnetic fields in combination with a confocal scanning laser microscope. It fits a typical cryocooler-operated superconducting magnet with a 100mm diam room-temperature bore. To avoid the unwanted effect of magnetic fields, the laser scanning unit was positioned at sufficient distance from the field. The resolution obtained was several hundreds of nanometers. The observation area can be changed in situ by the xyz fine-motion stage. Processing of obtained images can be done in a manner nearly identical to that with a conventional confocal scanning laser microscope. Images of the in situ observation of electroless silver deposition under a 12T field are presented.
Highly efficient top emitting organic light-emitting diodes with organic outcoupling enhancement layers
Authors: Huang Qiang , Walzer Karsten , Pfeiffer Martin , Lyssenko Vadim , He Gufeng , Leo Karl
Published: March 2006

We demonstrate high-efficiency top emitting organic light-emitting diodes employing silver (Ag) for both anode and cathode. Following the p-i-n doping and double emission layer concepts, the devices show a very high efficiency of 50cd∕A at 1000cd∕m2 with a driving voltage of only 2.85V. The efficiency can be further improved to 78cd∕A by tuning the optical structure with an organic capping layer. A simple explanation based on the transmittance of the top contact cannot explain this efficiency enhancement. Instead, we theoretically show that this capping effect is dependent on the overall optical structure of the device.
Predictions for partial-dislocation-mediated processes in nanocrystalline Ni by generalized planar fault energy curves: An experimental evaluation
Authors: Wu Xiao-Lei , Zhu Y. T. , Ma E.
Published: March 2006

Generalized planar fault energy (GPFE) curves have been used to predict partial-dislocation-mediated processes in nanocrystalline materials, but their validity has not been evaluated experimentally. We report experimental observations of a large quantity of both stacking faults and twins in nc Ni deformed at relatively low stresses in a tensile test. The experimental findings indicate that the GPFE curves can reasonably explain the formation of stacking faults, but they alone were not able to adequately predict the propensity of deformation twinning.
Superductile bulk metallic glass
Authors: Yao K. F. , Ruan F. , Yang Y. Q. , Chen N.
Published: March 2006

Usually, monolithic bulk metallic glasses undergo inhomogeneous plastic deformation and exhibit poor ductility (<2%) at room temperature. We report a newly developed Pd–Si binary bulk metallic glass, which exhibits a uniform plastic deformation and a large plastic engineering strain of 82% and a plastic true strain of 170%, together with initial strain hardening, slight strain softening and final strain hardening characteristics. The uniform shear deformation and the ultrahigh plasticity are mainly attributed to strain hardening, which results from the nanoscale inhomogeneity due to liquid phase separation. The formed nanoscale inhomogeneity will hinder, deflect, and bifurcate the propagation of shear bands.