bluuebunny/crossref_metadata_2025 huggingface dataset:
‘De novo’ sequencing of Atlantic cod vitellogenin tryptic peptides by matrix‐assisted laser desorption/ionization quadrupole time‐of‐flight tandem mass spectrometry: similarities with haddock vitellogenin
Authors: Cohen Alejandro M. , Mansour Atef A. H. , Banoub Joseph H.
Published: July 2005

Vitellogenin is a protein produced by the liver of oviparous animals in response to circulating estrogens. The amino acid sequence of vitellogenin from Atlantic cod (Gadus morhua) has not yet been determined. In this study Atlantic cod vitellogenin was characterized using a ‘bottom‐up’ mass spectrometric approach. Vitellogenin synthesis was induced ‘in vivo’ with β‐estradiol, and subjected to trypsin digestion for characterization by matrix‐assisted laser desorption/ionization quadrupole time‐of‐flight tandem mass spectrometry. A peptide mass fingerprint was obtained and ‘de novo’ sequencing of the most abundant tryptic peptides was performed by low‐energy collision‐induced dissociation tandem mass spectrometry. As a result of these experiments, the sequences of various tryptic peptides have been elucidated. The database search has shown that Atlantic cod vitellogenin shares a series of common peptides with the two different known vitellogenin sequences of haddock, a closely related species. These findings allow us to propose that Atlantic cod might also co‐express at least two distinct forms of vitellogenin. Copyright © 2005 John Wiley & Sons, Ltd.
Total synthesis of ciguatoxin CTX3C: a venture into the problems of ciguatera seafood poisoning
Authors: Hirama Masahiro
Published: July 2005

After a twelve‐year struggle, the total synthesis of ciguatoxin CTX3C has been achieved. Annually, more than 20,000 people worldwide suffer from ciguatera seafood poisoning. The extremely small amounts of the causative neurotoxin, ciguatoxin, in fish hampered the isolation, structural elucidation, detailed biological study, and preparation of anti‐ciguatoxin antibodies for detecting these toxins. The large (3 nanometers long) and complicated molecular structure of ciguatoxins hindered chemists from completing a total synthesis. The chemical synthesis of CTX3C, determination of the absolute configuration, and synthesis‐based preparation of the monoclonal antibodies as well as the effect of synthetic CTX3C on voltage‐sensitive sodium channels are outlined. © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 240–250; 2005: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20049
Characterization of surface carbon films on weathered Japanese roof tiles by soft x‐ray spectroscopy
Authors: Muramatsu Yasuji , Yamashita Michiru , Motoyama Muneyuki , Hirose Mika , Denlinger Jonathan D. , Gullikson Eric M. , Perera Rupert C. C.
Published: July 2005

The effects of weathering on carbon films deposited on Japanese smoked roof tiles were investigated by soft x‐ray absorption and emission spectroscopy using synchrotron radiation. X‐ray absorption measurements revealed that weathering oxidizes the carbon films and that partial carboxy chemical bonding occurs. Incident angle‐dependent x‐ray absorption spectra in the C K region confirmed that the degree of the orientation at the surface of the oxidized carbon films decreases with weathering. However, the take‐off angle‐dependent C K x‐ray emission spectra showed that the orientation of the layered carbon structure is maintained in the bulk portion when weathered. Therefore, it is confirmed that oxidation proceeds from the surface of the carbon films. Weathering degrades and oxidizes the surface carbon films, which causes the metallic silver color to change to darker gray. Copyright © 2005 John Wiley & Sons, Ltd.
Effect of Intraperitoneal Application of an Endotoxin Inhibitor on Survival Time in a Laparoscopic Model of Peritonitis in Rats
Authors: Kuhn Roger , Schubert Daniel , Tautenhahn Joerg , Nestler Gerd , Schulz Hans‐Ulrich , Bartelmann Maike , Lippert Hans , Pross Matthias
Published: August 2005

Gram‐negative sepsis due to fecal peritonitis is a hazardous disease with a high percentage having a lethal course. The inflammatory effects are induced by endotoxin release. We performed this study to evaluate the potential of direct intraperitoneal application of an endotoxin inhibitor in a laparoscopic peritonitis model in rats. The human feces specimen was prepared, and a standard fecal specimen (0.5 ml/kg b.w.) was applied via minilaparotomy. The rats were randomized to two studies. First, rats were randomized to three groups to define the survival time: (1) rats without further manipulation; (2) rats with laparoscopic lavage using NaCl; (3) rats with laparoscopic lavage using endotoxin inhibitor. Second, rats underwent the same procedure used in the first part of the study and an additional group with only NaCl lavage without peritonitis was randomized. To evaluate the immunologic or biochemical effects, animals were killed at a standard time of 20 hours until the postmortem examination was established. Interleukins 6 and 10 (IL‐6, IL‐10), malondialdehyde, and protein carbonyl group levels in plasma and particularly in peritoneal fluid were assayed. The first part of the experiment showed significantly increased survival after endotoxin inhibitor lavage. In the second part, administration of endotoxin inhibitor intraperitoneally caused a significant reduction of IL‐6 in the peritoneal fluid, in contrast to that in the other groups. Laparoscopic application of endotoxin inhibitor intraperitoneally thus produced a beneficial effect on survival and reduction of IL‐6 in peritoneal fluid. Hence, it is possible to influence the inflammation cascade by causing intraperitoneal endotoxin inhibition.
Haematopoietic stem cells improve cardiac function after infarction without permanent cardiac engraftment
Authors: Limbourg Florian P. , Ringes‐Lichtenberg Stefanie , Schaefer Arnd , Jacoby Christoph , Mehraein Yasmin , Jäger Mark D. , Limbourg Anne , Fuchs Martin , Klein Gunnar , Ballmaier Matthias , Schlitt Hans‐J. , Schrader Juergen , Hilfiker‐Kleiner Denise , Drexler Helmut
Published: August 2005

Background:

Transplantation of bone marrow derived adult stem cells (BMC) improves cardiac function after acute myocardial infarction (MI). However, the cell population mediating myocardial recovery and the fate of the transplanted cells are still controversial.

Aims:

We determined the effects of Sca‐1+ c‐kit+ lin‐ haematopoietic BMC on cardiac function after MI and the cell fate after transplantation.

Methods:

Sca‐1+ c‐kit+ lin‐ BMC of male donor C57BL/6 mice were transplanted by intravenous injection into syngenic females after permanent MI. LV dimensions and function were determined by echocardiography and cardiac magnetic resonance imaging, transplanted BMC were identified by Y chromosome DNA in situ hybridization.

Results:

BMC treatment completely prevented LV dilation (LV enddiastolic volume BMC 70±16 μl vs. control 122±41 μl; p <0.05) and improved fractional shortening (BMC 22.9±8% vs. control 15.4±8.4%; p <0.05) and ejection fraction (BMC 68.2±6.6% vs. control 52±14.3%, p <0.05) as early as 3 days after transplantation, but did not decrease infarct size (BMC 27±6% vs. control 28±7%, p =n.s.). After 4 weeks, only sporadic cells of male origin were identified in infarcted hearts (<0.01% of periinfarct cells).

Conclusion:

Intravenous injection of sca‐1+ c‐kit+ lin− BMC after MI improves LV dimensions and function without evidence for long term engraftment.
An integrative model of mouse cardiac electrophysiology from cell to torso
Authors: Tranquillo Joseph V. , Hlavacek James , Henriquez Craig S.
Published: July 2005

Aims

Although the transgenic mouse has become an important new tool in the study of human diseases and the design of new therapies, a complete picture of cardiac electrophysiology in the mouse, from genome to body surface, is lacking. A computational model of the mouse heart is presented, which is used to study the impact of ion-channel and structural manipulations on the distributions of extracellular potentials on the heart and body surface.

Methods

A model of the mouse heart anatomy, fibre organization and torso geometry was constructed from DTMRI images. An anisotropic bidomain model, with a modified Pandit et al. model for the ionic currents, was used to represent the electrical properties of the tissue. Spatial heterogeneity in the ion currents was introduced by modulating the transient outward current. A sinus beat was simulated in hearts with different tissue and membrane properties and the extracellular potentials were computed at both the heart and body surface.

Results

The simulated transmembrane patterns in the heart, and the timing and morphology of the simulated ECG waveforms were consistent with experimental measurements. In addition, the patterns of activation and recovery and the waveforms of the corresponding ECG were found to be relatively insensitive to changes in cell type distribution and tissue anisotropy.

Conclusion

Because of the small size of the heart, an integrative model of mouse electrophysiology can be simulated from cell to torso, enabling a new tool to study how extracellular signals might be used to detect molecular changes underlying an arrhythmogenic substrate.
Appropriation and Resistance: Local Responses to Malaria Eradication in Mexico, 1955–1970
Authors: CUETO MARCOS
Published: July 2005

Medical developments in Latin America during the second half of the twentieth century have received little attention. This study examines the Mexican responses to the success and failures of an important international health campaign of the 1950s: malaria eradication. During the 1950s malaria became the disease of central concern for international and US agencies working in developing countries (as yellow fever and hookworm were for tropical health during the early twentieth century). This article outlines the motivations, design and techniques of the campaign. It concentrates on two local responses: first, the enthusiastic support displayed by personnel working in the field; and, secondly, the reactions against the campaign of a local doctor – who revealed some of the inadequacies of malaria eradication – and of two medical anthropologists, who emphasised the scant attention paid to the cultural and social aspects of the campaign.
Good, God, and the open-question argument
Authors: FISHER ANDREW
Published: August 2005

In Finite and Infinite Goods, Robert Adams defends his metaphysical account that good is resemblance to God via an ‘open-question’ intuition. It is, however, unclear what this intuition amounts to. I give two possible readings: one based on the semantic framework Adams employs, and another based on Adams's account of humankind's epistemological limitations. I argue that neither of these readings achieves Adams's advertised aim.
Soil faunal biodiversity and nutrient status in silvopastoral systems of Indian desert
Authors: TRIPATHI G. , RAM S. , SHARMA B.M. , SINGH G.
Published: August 2005

Decrease in productivity of pastureland is a common problem in dry areas and needs to be enhanced through conservation and management of soil biodiversity and available plant resources. Diversity and population dynamics of soil arthropods, and soil nutrients were studied in different silvopastoral (tree-integrated grassland) systems for effective management and enhancement of grassland productivity. The most prominent combinations of trees and grasses in silvopastoral systems of the selected sites were Prosopis cineraria with Cenchrus ciliaris and C. biflorus (PC), Acacia nilotica with Elusine compressa and C. ciliaris (AN), Zizyphus nummularia with C. ciliaris and E. compressa (ZN), Capparis decidua with C. biflorus and Digitaria marginatus (CD) and A. senegal with C. ciliaris and D. marginatus (AS). Pure grass blocks outside tree canopy were selected as control plots. Acari, Myriapoda, Coleoptera, Isoptera, Collembola and other soil arthropods were the major soil faunal groups. Relative densities of Acari, Myriapoda and other arthropods were highest in silvopastoral systems and those of Coleoptera, Isoptera and Collembola were highest in pure grass plots. Variations in soil arthropod populations in response to rainfall, soil water content and soil temperature indicated greater sensitivity of these groups to environmental factors. The highest densities and negative relative tree effect (RTE) values of Acari, Myriapoda and other soil arthropods in the ZN, Coleoptera in the AS, Isoptera in the CD and Collembola in the AN systems indicated that these soil arthropods preferred the silvopastoral systems involved. Seasonal variations in soil organic matter and available NH4-N, NO3-N and PO4-P were similar to those of soil arthropods. The concentrations of soil nutrients were highest in the ZN system, which had the highest densities of soil arthropods. The other systems with high populations and soil nutrient status were the CD and AS. Silvopastoral systems based on Z. nummularia, C. decidua and A. senegal promoted soil arthropod populations and enhanced soil nutrient status, highlighting the positive role of tree presence and the need for proper management to promote soil biodiversity, nutrient cycling and sustained production in a fragile environment.
Foraging characteristics of an assemblage of four Sumatran hornbill species
Authors: HADIPRAKARSA YOK-YOK , KINNAIRD MARGARET F.
Published: August 2005

This study examines the diets of four hornbill species (Bushy-crested Hornbill Anorrhinus galeritus, Wreathed Hornbill Aceros undulatus, Rhinoceros Hornbill Buceros rhinoceros and Helmeted Hornbill Buceros vigil) common within our 9 km2 study area in the Bukit Barisan Selatan National Park, Sumatra, Indonesia. Line transects and opportunistic sampling were used over one year to collect feeding data, including the tree species and strata in which birds fed, diet items, fruit characteristics and tree crop size. Hornbills fed on 64 species. Figs, non-fig fruits and animals comprised 23.4% (n = 15 species) 51.6% (n = 33 species) and 25% (n = 16 species) of the diet, respectively. Although there was overlap among the diets of the four species, only B. rhinoceros and B. vigil had a statistically significant overlap, primarily due to high fig consumption by both species. B. vigil fed almost exclusively on figs (98.6% of the diet) and a small proportion of animals (1.4%) while 23.1% of the B. rhinoceros diet comprised non-fig fruits and animals (23.1%), with 76.9% figs. A. galeritus and A. undulatus had distinct diets with drupaceous, oily fruits comprising 66.7% and 64.4% of the diets, respectively. We found no significant relationship between the numbers of hornbills visiting fruiting trees and the characteristics of the fruit (weight, length and width). However, maximum crop sizes of diet species significantly influenced the number of feeding hornbills. Hornbill species also differed in the strata in which they fed. A. galeritus and B. rhinoceros were seen in the middle of the canopy 56% and 50.8% of the time, respectively while A. undulatus and B. vigil were observed more frequently in the upper canopy (50% and 74.3% of the time, respectively). The lower part of the canopy was used infrequently by all species. This study suggests that the four hornbill species in our study partition food resources by food type and/or feeding location.
What Do You Desire? What Do You Fear? Theorize it!
Teaching Political Theory through Utopian Writing
Authors: Haddad Khristina
Published: August 2005

Undergraduate students should not just study political theory. They
should theorize. Writing-intensive political theory courses can help
them do so sooner. By preparing an original political vision, a
utopia or a dystopia, throughout the course of the semester,
students read and compare the texts of the course against their own
emerging texts and move into more critical and systematic political
analysis. As a political theorist, my focus is not so much on
utopias or dystopias as a subject of study per se,
but on tapping into the creative freedom, critical distance, and
hard-hitting insights of these traditions while teaching writing. I
take seriously Berlin's above-stated concern for the “place and mode
of operation” conveyed to the student through the process of
learning to write. Visionary writing accelerates students'
appreciation of the complexity of another's theory, but also of
their own standpoint and capacity for agency and judgment. Khristina Haddad is assistant professor,
department of political science, Moravian College. She teaches a
writing-intensive course on visionary political writing and is
affiliated with German Studies and Women's Studies. Her research
interests include politics of time and temporality, Hannah
Arendt, political action, fear, feminist theory, women's
studies, and, in particular, the politics of women's
health. I am greatly indebted
to friends and colleagues who helped me along at various stages
including (in alphabetical order) Robert Humanick, Eleanor Linn,
Bob Mayer, Karla Morales, Laurie Naranch, Gary Olson, Miguelina
Ortiz, Martha Reid, Joanna Vecchiarelli Scott, Lyman Tower
Sargent, Joel Wingard, and Elizabeth Wingrove. Thanks go also to
all those whose dedicated work inspires student writers and
teachers of writing at the Gayle Morris Sweetland Writing Center
at the University of Michigan, to helpful commentators at the
Society for Utopian Studies' Annual Meeting in Toronto, to two
anonymous reviewers at PS, and to three groups
of students who shared their visions with me.
In Memoriam - Conrad Joyner
Authors: Dixon William J.
Published: August 2005

Conrad Joyner, an astute observer, gifted teacher, and effective
practitioner of the art of politics, passed away February 8, 2005,
in Tucson, Arizona. Born October 21, 1931, he graduated from Earlham
College in 1953 and received his Ph.D. from the University of
Florida in 1957. He taught political science at West Virginia
University and the University of Southwestern Louisiana before
arriving at the University of Arizona in 1961 for what would turn
out to be a long and colorful career. He retired from the University
of Arizona in 1992.
Environments and evolution: interactions between stress, resource inadequacy and energetic efficiency
Authors: Parsons Peter A.
Published: August 2005

Evolutionary change is interpreted in terms of the near‐universal ecological scenario of stressful environments. Consequently, there is a premium on the energetically efficient exploitation of resources in a resource‐inadequate world. Under this environmental model, fitness can be approximated to energetic efficiency especially towards the limits of survival. Furthermore, fitness at one stage of the life‐cycle should correlate with fitness at other stages, especially for development time, survival and longevity;‘good genotypes’ under stress should therefore be at a premium. Conservation in the wild depends primarily on adaptation to abiotically changing habitats since towards the limits of survival, genomic variation is rarely restrictive. The balance between energetic costs under variable environments and energy from resources provides a model for interpreting evolutionary stasis, punctuational and gradual change, and specialist diversification. Ultimately, a species should be in an equilibrium between the physiology of an organism and its adaptation to the environment. The primary key to understanding evolutionary change should therefore be ecological, highlighting energy availability in a stressed world; this approach is predictive for various patterns of evolutionary change in the living and fossil biota.
Effects of glutathione depletion on the viability of human NT2-derived neuronal and astroglial cultures
Authors: BYRD ANGÈLE S. , SIKORSKA MARIANNA , WALKER P. ROY , SANDHU JAGDEEP K.
Published: July 2005

The level of glutathione (GSH) is often reduced in brains that are affected by neurodegeneration. It is not known, however, whether this is a cause or a consequence of the disease. Here we have examined the effects of GSH depletion on the viability of human neurons cultured in either the presence or the absence of astrocytes, both derived from NT2/D1 cells. We established that the endogenous concentration of GSH is 10 times lower in neurons than in astrocytes (1.42 versus 18.9 pmol µg protein−1) and that pure neuronal cultures begin to die by apoptosis within 24 h of GSH depletion. By contrast, neurons that are co-cultured with astrocytes remain viable for several days, even with a profoundly decreased GSH content. However, they die rapidly when challenged additionally with nitrative stress. In addition, astrocytes survive for prolonged periods of time (>12 days) under severely reduced GSH concentrations. Our study shows clear differences in the content and sensitivity to depletion of GSH in neurons and astrocytes and establishes the significance of neuronal–glial interactions for the maintenance of neuronal viability under reduced GSH content. However, with chronic GSH depletion, these interactions might not be sufficient to protect neurons from other injurious factors (i.e. reactive oxygen and nitrogen species), which indicates that defective GSH metabolism might facilitate the progression of neurodegeneration.
Experience-driven brain plasticity: beyond the synapse
Authors: MARKHAM JULIE A. , GREENOUGH WILLIAM T.
Published: July 2005

The brain is remarkably responsive to its interactions with the environment, and its morphology is altered by experience in measurable ways. Histological examination of the brains of animals exposed to either a complex (‘enriched’) environment or learning paradigm, compared with appropriate controls, has illuminated the nature of experience-induced morphological plasticity in the brain. For example, this research reveals that changes in synapse number and morphology are associated with learning and are stable, in that they persist well beyond the period of exposure to the learning experience. In addition, other components of the nervous system also respond to experience: oligodendrocytes and axonal myelination might also be permanently altered, whereas changes in astrocytes and cerebrovasculature are more transient and appear to be activity- rather than learning-driven. Thus, experience induces multiple forms of plasticity in the brain that are apparently regulated, at least in part, by independent mechanisms.
Resolving the enigmatic solar wind disappearance event of 11 May 1999
Authors: Janardhan P. , Fujiki K. , Kojima M. , Tokumaru M. , Hakamada K.
Published: August 2005

On 11 and 12 May 1999, the Earth was engulfed by an unusually low‐density (<1 cm−3) and low‐velocity (<350 km s−1) solar wind for a period of over 1 day. Extensive studies of this unusual event that occurred during Carrington rotation 1949 (CR1949), using both ground‐based and space‐based in situ observations, have not as yet been able to identify the cause or the solar source of this event. Using solar wind velocity measurements from the four‐station IPS observatory of the Solar‐Terrestrial Environment Laboratory (STEL), Toyokawa, Japan, we investigate the structure of the solar wind in May 1999 during CR1949. IPS observations from STEL were used to make tomographic velocity maps to identify and delineate the extent and morphology of the stable solar wind flows during CR1949 in the vicinity of the Earth. Combined with in situ measurements of the interplanetary magnetic field (IMF), potential field computations of the solar magnetic fields in the period, and HeI 10830Å observations of coronal hole boundaries during CR1949, we have identified the source region of the unusual flows and have shown that the flow responsible for the “disappearance event” was a stable unipolar flow originating in the vicinity of a large midlatitude active region AR8525, located at ∼18°N and between heliographic longitudes 280° and 300°. Earlier workers have speculated that such events may be caused by the large‐scale restructuring of the solar magnetic field at the maximum of each solar cycle. However, by identifying the solar source and nature of this event, we believe that at least in this particular case, the association with global, large‐scale solar phenomena like the periodic 11‐year solar polar field reversal is most likely to be coincidental.
Effects of the induction field on the Sq dynamo currents in the ionosphere
Authors: Takeda Masahiko
Published: August 2005

Effects of the induction field on the ionospheric currents generated by the Sq dynamo were studied using current function. It was shown that the induction field significantly affects the ionospheric currents only if the field is artificially enhanced by 100 times. Existence of the spherical inner conductor reduces the effects because currents induced in the sphere partly cancel vertical component of the variation field. On the other hand, it is probable that the induction field should be considered for the simulation of the ionospheric current with the period of less than 10 min. because the induction field affects the ionospheric Sq currents if the field is enhanced by 100 times.
Paleomagnetism and tectonic significance of Albian and Cenomanian turbidites, Ochoco Basin, Mitchell Inlier, central Oregon
Authors: Housen Bernard A. , Dorsey Rebecca J.
Published: July 2005

Understanding continental growth and convergent margin dynamics associated with terrane accretion and modification of the Cordilleran margin of North America is prevented by conflicts in paleogeographic models for major terranes, oceanic plates, and the North American margin. We present new paleomagnetic data suggesting that the Blue Mountains superterrane, located at an inboard portion of the Cordilleran margin, has undergone substantial northward translation and clockwise rotation relative to North America since mid‐Cretaceous time. Positive baked‐contact, conglomerate, and fold tests, provide evidence that the magnetization of these rocks dates from their deposition. These results yield a mean direction of D = 10.8°, I = 58.5°, k = 127, α95 = 4.1°, and N = 11. Comparison of magnetic inclinations and magnetic fabrics shows no evidence for inclination error. A paleolatitude of 39.2° +4.8°/−4.3°N is obtained, indicating a paleolatitude anomaly of 15.9° ± 4.1° (northward translation of 1760 ± 460 km) and CW rotation of 37° ± 7.3° with respect to North America since circa 93 Ma. Application of an ad hoc 5° inclination error yields translation of 1200 ± 460 km. Through comparison with other units in the western Cordillera we infer that the Mitchell Inlier was located adjacent to the Sierra Nevada arc during mid‐Cretaceous time and that the Blue Mountains province may correlate with the Intermontane superterrane in British Columbia. Other interpretations, such as large inclination errors or an independent displacement history for the Mitchell Inlier, are possible but unlikely. More work is needed to fully test these hypotheses and resolve major questions of Cordilleran tectonics.
Can carbon dioxide be used as a tracer of urban atmospheric transport?
Authors: Pataki D. E. , Tyler B. J. , Peterson R. E. , Nair A. P. , Steenburgh W. J. , Pardyjak E. R.
Published: August 2005

Carbon dioxide is a stable constituent of the atmosphere that has no major terrestrial sinks other than atmospheric transport in the absence of photosynthetic activity by plants. In urban atmospheres, CO2 mixing ratios are often elevated above ambient by large local sources from combustion. We measured CO2 mixing ratios and the isotopic composition of CO2 at four locations in the Salt Lake Valley, Utah, during a persistent cold pool event in the winter of 2004. The results showed a strong influence of atmospheric stability and the height of the capping inversion on CO2 mixing ratios and suggested that during persistent cold pool events the air mass beneath the capping inversion can be relatively well mixed. Spatial and temporal patterns in the isotopic composition of CO2 and the relationship between particulate concentrations and CO2 mixing ratio support this interpretation. These results suggest that CO2 mixing ratio, which is abundant and relatively easily measured in urban atmospheres, can provide information about complex wintertime atmospheric transport and mixing as well as carbon cycling in urban mountain basins.
Geostatistical inverse modeling of transient pumping tests using temporal moments of drawdown
Authors: Li Wei , Nowak Wolfgang , Cirpka Olaf A.
Published: August 2005

Pumping tests belong to the most common techniques of hydrogeological site assessment. While the steady state drawdown is determined by the distribution of transmissivity alone, the transient behavior is also influenced by the storativity field. In geostatistical inverse modeling the spatial distributions of both transmissivity and storativity are inferred from the drawdown curves and prior information on the spatial correlation of the parameter fields. So far, however, transient data have hardly been analyzed by geostatistical inverse methods because the computational effort is rather high. In the present study, we characterize the drawdown by its temporal moments. We present moment‐generating equations and corresponding equations to compute the sensitivity of the temporal moments of drawdown with respect to the distributions of transmissivity and storativity. We utilize these equations to infer the transmissivity and storativity fields from transient pumping tests using the quasi‐linear geostatistical approach of inverse modeling. Considering temporal moments rather than full drawdown curves drastically reduces the computational effort of the estimation procedure. In test cases we show that the first two temporal moments are sufficient to characterize the drawdown curves. We investigate how erroneous assumptions regarding the spatial variability of storativity affect the estimate of the transmissivity field, and we analyze the effect of truncating the measured drawdown curves.
A comparison of global spatial distributions of nitrogen inputs for nonpoint sources and effects on river nitrogen export
Authors: Van Drecht G. , Bouwman A. F. , Boyer E. W. , Green P. , Siebert S.
Published: July 2005

We compared four global data sets for the year 1995 for nonpoint N sources with 0.5° by 0.5° spatial resolution. Data were developed to drive models for assessing the river export of nitrogen (N) at the global scale. The data include annual N inputs (biological N fixation, atmospheric N deposition, N fertilizer, animal manure, and human emissions) and outputs (ammonia volatilization and N removed from agricultural fields by harvesting crops and grass consumption). There are important differences at the global, regional, country, and river‐basin scales for all input and output terms in the data sets. The main differences are in the rates and the spatial allocation for biological N fixation and atmospheric N deposition, animal manure inputs and management, and N in harvested crops and grass consumption. Inputs of N fertilizer in agricultural systems are relatively well known at the country scale (and subnational scale for some large countries), but their spatial allocation also shows major differences between the four data sets. The level of disagreement between the different data sets increases with decreasing river basin size, which is related to the difficulty of spatial allocation when river basins cover only a few grid cells. Transport efficiencies to calculate river N export from the N surplus obtained from a regression approach and from a meta model derived from a conceptual model are in good agreement when aggregated to continents and receiving oceans.
Absence of energetic particle effects associated with magnetic reconnection exhausts in the solar wind
Authors: Gosling J. T. , Skoug R. M. , Haggerty D. K. , McComas D. J.
Published: July 2005

We have examined energetic particle data (>38 keV for electrons and >47 keV for protons) obtained in intervals surrounding a set of 7 encounters with Petschek‐type reconnection exhausts in the solar wind by the Advanced Composition Explorer. We find no evidence for any substantial increases in energetic particle intensity associated with those encounters. This indicates that local reconnection is not a significant source of energetic particles in the solar wind and suggests the possibility that reconnection itself may not be a particularly effective process for populating other space and astrophysical environments with energetic particles.
Deriving surface ultraviolet radiation from CERES surface and atmospheric radiation budget: Methodology
Authors: Su Wenying , Charlock Thomas P. , Rose Fred G.
Published: July 2005

We describe an algorithm that retrieves the surface UVB (280–315 nm) and UVA (315–400 nm) irradiances from the Surface and Atmosphere Radiation Budget (SARB) product of Clouds and the Earth's Radiant Energy System (CERES). The SARB product we use here routinely calculates the vertical profiles of shortwave, longwave, and window channel irradiances with inputs of retrievals from imagers collocated with CERES. The top of the atmosphere broadband irradiance from SARB is constrained by CERES broadband irradiance. The shortwave spectrum in the SARB calculation is divided into 15 bands, and the two ultraviolet spectral bands, band 5 (298.5–322.5 nm) and band 6 (322.5–357.5 nm), are used to generate surface UVB and UVA irradiances. In this study, we develop a set of ratio lookup tables to derive surface UVB and UVA irradiances from SARB band 5 and band 6 outputs. We show that the ratio of band 5 to UVB irradiance is sensitive to total column ozone, solar zenith angle, surface albedo, and the atmospheric profile in cloud‐free conditions; in cloudy conditions, the ratio of band 5 to UVB irradiance is also sensitive to cloud optical depth and height. Additionally, we show that the ratio of band 6 to UVA irradiance is sensitive to solar zenith angle, surface albedo, and cloud optical depth. We also derive a UV index from the UVB irradiance. Our algorithm may be applied at any surface elevation or surface type, including snow and ice. Surface UV irradiances derived from the lookup table that we created agree well with those computed by the high‐resolution, multistream radiative transfer code, with differences ranging from −10% to +4% for UVB and UVA irradiances. The relative differences for the UV index are higher, ranging from −26% to +16%.
A role of SAND-family proteins in endocytosis
Authors: Poteryaev D. , Spang A.
Published: August 2005

Caenorhabditis elegans has recently been used as an attractive model system to gain insight into mechanisms of endocytosis in multicellular organisms. A combination of forward and reverse genetics has identified a number of new membrane trafficking factors. Most of them have mammalian homologues which function in the same transport events. We describe a novel C. elegans gene sand-1, whose loss of function causes profound endocytic defects in many tissues. SAND-1 belongs to a conserved family of proteins present in all eukaryotic species, whose genome is sequenced. However, SAND family has not been previously characterized in metazoa. Our comparison of C. elegans SAND-1 and its yeast homologue, Mon1p, showed a conserved role of the SAND-family proteins in late steps of endocytic transport.
Cannabinoids and cancer: potential for colorectal cancer therapy
Authors: Patsos H.A. , Hicks D.J. , Greenhough A. , Williams A.C. , Paraskeva C.
Published: August 2005

Despite extensive research into the biology of CRC (colorectal cancer), and recent advances in surgical techniques and chemotherapy, CRC continues to be a major cause of death throughout the world. Therefore it is important to develop novel chemopreventive/chemotherapeutic agents for CRC. Cannabinoids are a class of compounds that are currently used in the treatment of chemotherapy-induced nausea and vomiting, and in the stimulation of appetite. However, there is accumulating evidence that they could also be useful for the inhibition of tumour cell growth by modulating key survival signalling pathways. The chemotherapeutic potential for plant-derived and endogenous cannabinoids in CRC therapy is reviewed.
Crystal structure of DMGO provides a prototype for a new tetrahydrofolate-binding fold
Authors: Scrutton N.S. , Leys D.
Published: August 2005

The crystal structure of DMGO (dimethylglycine oxidase) from Arthrobacter globiformis in complex with folate compounds has revealed a novel THF (tetrahydrofolate)-binding fold [Leys, Basran and Scrutton (2003) EMBO J. 22, 4038–4048]. This fold is widespread among folate-binding proteins. The crystal structures of aminomethyltransferase (T-protein), YgfZ and TrmE all reveal similar THF-binding folds despite little similarity in sequence or function. The THF-binding site is highly specific for reduced folate compounds and most members of this fold family enhance the nucleophilic character of the THF N10 position.
Inhibition of 7,8-diaminopelargonic acid aminotransferase by amiclenomycin and analogues
Authors: Mann S. , Marquet A. , Ploux O.
Published: August 2005

Cis and trans stereoisomers of amiclenomycin, a natural L-amino acid antibiotic, have been prepared using unequivocal routes. By using 1H NMR spectroscopy, the configuration of the six-membered ring of natural amiclenomycin was shown to be cis and not trans as originally proposed. Amiclenomycin and some synthetic analogues with the cis configuration irreversibly inactivate DAPA AT (7,8-diaminopelargonic acid aminotransferase), an enzyme involved in biotin biosynthesis, by forming an aromatic PLP (pyridoxal-5′-phosphate)–inhibitor adduct that is tightly bound to the active site. The following kinetic parameters for the inactivation of Escherichia coli DAPA AT by amiclenomycin were derived: KI=2 μM and kinact=0.4 min−1. The structure of the aromatic adduct formed upon inactivation was confirmed by UV–visible spectroscopy, X-ray crystal structure determination and MS. Because Mycobacterium tuberculosis DAPA AT is a potential drug target, this enzyme was cloned, overexpressed and purified to homogeneity for biochemical characterization.
Alfvén eigenmodes in reversed shear plasmas in JT-60U negative-ion-based neutral beam injection discharges
Authors: Takechi M. , Fukuyama A. , Ishikawa M. , Cheng C. Z. , Shinohara K. , Ozeki T. , Kusama Y. , Takeji S. , Fujita T. , Oikawa T. , Suzuki T. , Oyama N. , Morioka A. , Gorelenkov N. N. , Kramer G. J. , Nazikian R. ,   the JT-60 team
Published: August 2005

Rapid frequency sweeping modes observed in reversed magnetic shear (RS) plasmas on the Japan Atomic Energy Research Institute Tokamak 60 Upgrade (JT-60U) [H. Ninomiya and the JT-60 Team, Phys. Fluids B 4, 2070 (1992)] have been identified as reversed-shear-induced Alfvén eigenmodes (RSAEs), which are ideal magnetohydrodynamic Alfvén eigenmodes (AEs) localized to the region of minimum safety factor, qmin, and are excited by negative-ion-based neutral beam injection. The chirping and subsequent saturation of the mode frequency are consistent with theoretical predictions for the transition from RSAEs to toroidal Alfvén eigenmodes (TAEs). The previously observed rapid frequency sweeping modes in ion cyclotron wave heated plasmas in JT-60U can also be similarly explained. The observed AE amplitude is largest during the transition from RSAEs to TAEs, and fast ion loss is observed when the AE amplitude is largest at this transition. It is preferable to operate outside the transition range of qmin, e.g., 2.4<qmin<2.7 for the n=1AE to avoid substantial fast ion loss in RS plasmas.
Micro-x-ray absorption near-edge structure imaging for detecting metallic Mn in GaN
Authors: Martínez-Criado G. , Somogyi A. , Homs A. , Tucoulou R. , Susini J.
Published: August 2005

In this study, we report the application of a synchrotron radiation microprobe to the analysis of Mn valencies in GaN. X-ray absorption near-edge structure (XANES) images taken around MnK-edge in fluorescence detection mode reveal the concentration of oxidation states of Mn centers. By fitting the XANES curve for each point of the image, the distributions of the Mn0, Mn2+, and Mn3+ oxidation states are obtained. At low Mn concentrations, there is a homogeneous mixture of Mn2+ and Mn3+ centers, while at high Mn content strong spatial-dependent Mn0 and Mn2+ distributions characterize the XANES maps. In a supplementary way with respect to Mn2+, the Mn0 pattern suggests the presence of specific cluster-like features, indicating surface segregation of metallic Mn centers.
Electron cyclotron heating by whistler waves generated during the interaction of a laser pulse with a magnetized plasma
Authors: Sotnikov V. I. , Sentoku Y. , Krasovitskii V. B.
Published: August 2005

Numerical simulation of the interaction of a laser pulse propagating along the external magnetic field shows that, along with the electrostatic upper hybrid wave, a laser pulse can parametrically excite a broad spectrum of whistler waves with frequencies below the electron cyclotron frequency. Electron heating predominantly in the direction perpendicular to laser pulse propagation was observed in simulations. In this paper the possible mechanism of transverse electron heating associated with the turbulence of whistler waves parametrically excited by a laser pulse has been investigated.
A relaxation method for constructing a Beltrami flow in a bounded domain
Authors: Nishiyama Takahiro
Published: July 2005

It is shown that a time-dependent equation generates a Beltrami flow (or a force-free field) at time t=∞ from non-Beltrami initial data in an arbitrary bounded domain in three dimensions. The generated Beltrami flow has a zero normal component on the boundary and its helicity is equal to a prescribed value. The existence and uniqueness of a solution to the equation are guaranteed globally in time and no finite-time singularity occurs.
Brillouin imaging
Authors: Koski K. J. , Yarger J. L.
Published: July 2005

Using an angle-dispersive Fabry-Perot interferometer in a confocal backscattering geometry, we have obtained Brillouin images of several liquid and polymer materials. One- and two-dimensional images of heterogeneous samples are presented using longitudinal Brillouin frequency shifts and acoustic attenuation for contrast. The experimental resolution of the images is 20μm.
Probe of the Si nanoclusters to Er3+ energy transfer dynamics by double-pulse excitation
Authors: Falconieri M. , Borsella E. , De Dominicis L. , Enrichi F. , Franzò G. , Priolo F. , Iacona F. , Gourbilleau F. , Rizk R.
Published: August 2005

In this letter the dynamics of the energy transfer (ET) process from amorphous silicon nanoclusters (Si-nc) to Er3+ ions is investigated in co-doped silica glasses. Using a double pulse setup the recovery time of the sensitizing effect is monitored and direct evidence is found for the occurrence of a fast (few hundreds ns) ET process in a sample containing large (2nm) aggregates, while a slower transfer time of few microseconds is revealed in a sample containing very small (<1nm) aggregates.
Photoinduced changes of surface order in coumarin side-chain polymer films used for liquid crystal photoalignment
Authors: Bergmann G. , Jackson P. O. , Hogg J. H. C. , Stirner T. , O’Neill M. , Duffy W. L. , Kelly S. M. , Clark G. F.
Published: August 2005

Specular x-ray reflectivity probes morphological changes in a crosslinkable coumarin photoalignment polymer film resulting from ultraviolet irradiation. An ordered surface layer with density oscillations compatible with planar side-chain alignment is obtained before irradiation. The ordering is enhanced in the early stages of crosslinking. This is attributed to the photoinduced increase of mobility of the side-chains resulting from the creation of free volume by the crosslinking process. The expansion of the thin film confirms that free volume is created. The surface ordering decreases with prolonged ultraviolet irradiation because of increased material viscosity resulting from a high crosslinked density. The implications of surface ordering on liquid crystal photoalignment are discussed.
Determination of thermal and optical parameters of melanins by photopyroelectric spectroscopy
Authors: de Albuquerque J. E. , Giacomantonio C. , White A. G. , Meredith P.
Published: August 2005

Photopyroelectric spectroscopy (PPE) was used to study the thermal and optical properties of melanins. The photopyroelectric intensity signal and its phase were independently measured as a function of wavelength and chopping frequency for a given wavelength in the saturation part of the PPE spectrum. Equations for both the intensity and the phase of the PPE signal were used to fit the experimental results. From these fits we obtained for the first time, with great accuracy, the thermal diffusivity coefficient, the thermal conductivity, and the specific heat of the samples, as well as a value for the condensed phase optical gap, which we found to be 1.70eV.
Effect of hydrogen peroxide on catalase gene expression, isoform activities and levels in leaves of potato sprayed with homobrassinolide and ultrastructural changes in mesophyll cells
Authors: Almeida José M. , Fidalgo Fernanda , Confraria Ana , Santos Arlete , Pires Helena , Santos Isabel
Published: August 2005

The effect of hydrogen peroxide (H2O2) on catalase (CAT) isoform activities and amounts and on mRNA levels was studied in leaves from potato plants untreated and treated with homobrassinolide (HBR). Northern blot analysis revealed that 100 mm H2O2 supplied through the leaf petiole for 4 h did not induce CAT expression. In contrast, CAT1 and CAT2 responded differently to longer treatment, as CAT2 transcript levels increased markedly whereas CAT1 transcript levels remained unchanged. Western blot analysis showed disparity between the level of CAT1 transcript and CAT1 amount, which actually decreased after 28 h. CAT2 amount correlated well with transcript accumulation and CAT2 activity as visualised by zymogram analysis. H2O2 modified the relative importance of CAT isoforms. After 4 h, CAT1 was prevalent in untreated and H2O2-treated leaves. After 28 h, CAT2 was prevalent in H2O2-treated leaves; therefore, the quantified increase in total CAT activity in these leaves was due to the rise in CAT2. HBR pre-treatment increased CAT2 basal level not changing the pattern of CAT responses to H2O2, only lowering its amplitude. Even so, ultrastructural studies showed that HBR significantly reduced H2O2 negative effects on cellular sub-structures, allowing better recovery of affected structures and reducing the macroscopic injury symptoms on leaves, thus data point to a HBR protective role.