bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissecting the transcriptional activation function of the cell wall integrity MAP kinase
Authors: Kim Ki‐Young , Cosano Inmaculada C. , Levin David E. , Molina María , Martín Humberto
Published: April 2007

The cell wall integrity signalling MAP kinase of Saccharomyces cerevisiae, Slt2p/ Mpk1p, is activated in response to cell wall stress. Slt2 and its mammalian orthologue ERK5 are unusual among MAP kinases, in that they possess the ability to activate transcription of a GAL1‐lacZ reporter when fused to the DNA‐binding domain of the Gal4 transcription factor. In this study, we demonstrate that transcriptional activation of a Gal4–Slt2p fusion is responsive to cell wall stress and requires phosphorylation of Slt2p. We identify two neighbouring but separable transcription activation domains within the C‐terminal half of Slt2p. Additionally, we present data suggesting that intramolecular interactions controlled by phosphorylation of Slt2p regulate the function of these domains, which are masked by the N‐terminal catalytic domain under inactive conditions. Finally, we demonstrate that Slt2p self‐associates, probably through a glutamine‐rich region within the C‐terminal half of the protein. Copyright © 2007 John Wiley & Sons, Ltd.
Extraction of cell surface‐associated proteins from living yeast cells
Authors: Klis Frans M. , de Jong Marian , Brul Stanley , de Groot Piet W. J.
Published: April 2007

To extract cell surface‐associated proteins from living fungal cells, reducing agents such as β‐mercaptoethanol and dithiothreitol are often used. We show here that both compounds are moderately lipophilic and may perturb the plasma membrane, thus causing the release of cytosolic proteins, especially at high extraction temperatures. To avoid artifacts, we recommend using (a) a low concentration of the reducing agent for only a short period of time, and (b) an extraction temperature of 4 °C to protect the integrity of the plasma membrane. Similarly, biotinylation of cell surface proteins should be carried out at low temperatures in the absence of dimethylsulphoxide. Copyright © 2007 John Wiley & Sons, Ltd.
An electron microscope study of certain dispersions of detergents in oil
Authors: Peri J. B.
Published: April 2007

1. Electron micrographs of certain detergent and soap micelles presumably existing in oil solution are presented.

2. Both “spherical” and rodlike micelles appear to exist in oil. These micelles are apparently two molecular lengths in diameter. The rodlike micelles are of variable length, ranging up to over 300 Å. It seems likely that in some instances these rods are small linear aggregates of “spherical” micelles.

3. Association of rodlike micelles to form paracrystalline sheaves of long fibers is indicated. These structures apparently maintain fairly uniform spacings of from 80 Å to 100 Å between centers of the rods or fibers although the micelles appear to be only about 50 Å in diameter.

4. Aggregation of spherical micelles to form small colloid crystalline regions in large agglomerates is demonstrated.
Degradation of longicorn beetle (Coleoptera, Cerambycidae, Disteniidae) fauna caused by conversion from broad‐leaved to man‐made conifer stands of Cryptomeria japonica (Taxodiaceae) in central Japan
Authors: Makino Shun'ichi , Goto Hideaki , Hasegawa Motohiro , Okabe Kimiko , Tanaka Hiroshi , Inoue Takenari , Okochi Isamu
Published: April 2007

We studied the species richness and assemblages of longicorn beetles (Coleoptera, Cerambycidae, Disteniidae) in ten secondary broad‐leaved stands and eight plantation stands of Japanese cedar (Cryptomeria japonica) of various ages after clear‐cutting or plantation in Ibaraki, central Japan. The species richness of longicorns, which were collected with Malaise traps, was the highest in young stands, decreasing with the age of the stand for both broad‐leaved and conifer stands. A canonical correspondence analysis divided the 18 plots into three groups based on longicorn assemblages and environmental variables. These three groups consisted of (1) very young (1–4 years old) stands after clear‐cutting or plantation; (2) 12‐ to over 100 year‐old broad‐leaved stands; (3) 7‐ to 76‐year‐old conifer stands. The species richness of the longicorns was the highest in the young stands followed, in order of decreasing species richness, by broad‐leaved stands and conifer stands. Possible causes of the high species richness in young stands include large amounts of coarse wood debris and flowers, which are resources for oviposition and nutrition for adults, respectively. The lower longicorn diversity in conifer stands than in broad‐leaved stands may be due to the lower diversity of trees available as host plants in the former. Almost all species that occurred in conifer stands were also collected in young and/or broad‐leaved stands, but the reverse was not true, suggesting that conifer plantations cannot replace broad‐leaved stands in terms of longicorn biodiversity. We argue that an extensive conversion of broad‐leaved forests into conifer plantations will lead to an impoverishment of the longicorn fauna, which may result in the degradation of ecosystem functions possibly carried out by them.
Preparation, Surface‐Active Properties and Antimicrobial Activities of Bis(Ester Quaternary Ammonium) Salts
Authors: Węgrzyńska Joanna , Chlebicki Jan , Maliszewska Irena
Published: April 2007

New cationic surfactants, bis‐quaternary ammonium salts, were prepared from N,N‐dimethylaminoalkyl esters of saturated fatty acids and products of the reactions of epichlorohydrin with primary amines: pentyl‐, hexyl‐ and octylamine. The bis (ester–ammonium) salts obtained were examined in respect to their surface‐active properties: critical micelle concentration (CMC), effectiveness of surface tension reduction (γCMC), and adsorption efficiency (pC20). All these surfactants showed good water solubility and low critical micelle concentrations of more than two orders of magnitude lower than these of corresponding mono‐alkylammonium salts. They also showed good wetting capability, but worse foaming properties. All the surfactants tested were nontoxic to gram‐negative bacteria, but some of them inhibited the growth of gram‐positive bacteria and yeast.
Synthesis, Surface Properties and Antimicrobial Activity of Bolaamphiphile/Oppositely Charged Conventional Surfactant Mixed Systems
Authors: Ali Hanan El‐Sharkawy
Published: April 2007

Four ionic bolaamphiphiles were synthesized from four bolasingle systems and the surface properties of bolasingle systems and bola\oppositely charged conventional mixed surfactant systems were studied. Variations in the structure of the hydrophobic chain of bolaamphiphiles has a great influence on their antimicrobial activities. The bolaform surfactants prepared have significant antimicrobial and antifungal activities relative to their conventional analogues. The Г∞ (saturated adsorption amount) and Amin (minimum average area per surfactant molecule) of these bolaamphiphiles in both water and 0.1 M NaCl solutions were calculated and CMC of the mixed systems with oppositely charged conventional surfactants in both water and 0.1 M NaCl solutions were determined.
Expression of HtKNOT1, a class I KNOX gene, overlaps cell layers and development compartments of differentiating cells in stems and flowers of Helianthus tuberosus
Authors: Michelotti V. , Giorgetti L. , Geri C. , Cionini G. , Pugliesi C. , Fambrini M.
Published: April 2007

In plant, post‐embryonic development relies on the activities of indeterminate cell populations termed meristems, spatially clustered cell lineages, wherein a subset divides indeterminately. For correct growth, the plant must maintain a constant flow of cells through the meristem, where the input of dividing pluripotent cells offsets the output of differentiating cells. KNOTTED1‐like homeobox (KNOX) genes are expressed in specific patterns in the plant meristems and play important roles in maintaining meristematic cell identity. We have analyzed the expression pattern of HtKNOT1, a class I KNOX gene of Helianthus tuberosus, in stems, inflorescence meristems, floral meristems and floral organs. HtKNOT1 is expressed in cambial cells, phloem cells and xylematic parenchyma within apical stem internodes, while in basal internodes HtKNOT1 expression was restricted to the presumptive initials and recently derived phloem cells. In the reproductive phase, HtKNOT1 mRNAs were detected in both the inflorescence and floral meristems as well within lateral organ primordia (i.e. floral bracts, petals, stamens and carpels). In more differentiated flowers, the expression of HtKNOT1 was restricted to developing ovules and pollen mother cells. HtKNOT1 may play a dual role being required to maintain the meristem initials as well as initiating differentiation and/or conferring new cell identity. In particular, it is possible that HtKNOT1 cooperates at floral level with additional factors that more specifically control floral organs and pollen development in H. tuberosus.
Impact of heart failure and left ventricular function on long‐term survival — Report of a community‐based cohort study in Taiwan
Authors: Huang Chien‐Hua , Chien Kuo‐Liong , Chen Wen‐Jone , Sung Fung‐Chang , Hsu Hsiu‐Ching , Su Ta‐Chen , Lee Yuan‐Teh
Published: March 2007

Background:

There is little community‐based information on heart failure (HF) prognosis in ethnic Chinese populations, in whom there is a low prevalence of coronary heart disease.

Aims:

To study the impact of HF and left ventricular function on long‐term all‐cause mortality.

Methods and results:

This community‐based prospective cohort study included 2660 subjects (1215 men, 1445 women, mean age 54.4±11.9 years) over a 10 year follow‐up period. The prevalence of HF was 5.5%. Hypertension was the most common factor related to HF. The five and ten year all‐cause mortality was higher in the HF/preserved LVEF group (14.1% and 24.4%) and the HF/impaired LVEF group (29.2% and 48.2%) than in the HF‐free group (6.0% and 14.6%, p<0.0001 for both). In multivariable Cox analyses, controlling for sex, LV mass, atrial fibrillation, hypertension, coronary heart disease, HF/preserved LVEF and HF/impaired LVEF were important predictors of all‐cause mortality (p=0.007).

Conclusions:

Hypertension is a major heart failure related disease. HF and LV systolic dysfunction are associated with a significant increase in all‐cause mortality in an ethnic Chinese population.
Up‐regulation of the Ku heterodimer in Drosophila testicular cyst cells
Authors: Boutanaev Alexander M. , Mikhaylova Lyudmila M. , Nurminsky Dmitry I.
Published: March 2007

In Drosophila, developing germline cysts in testis are enveloped by two somatic cyst cells essential for germline development and male reproduction. The cyst cells continue development along with the germline. However, the mechanisms of somatic gene expression in testes are poorly understood. We report transcriptional up‐regulation of the Ku heterodimer in cyst cells. The initial up‐regulation is independent of germline, and transcription is further augmented during spermatogenesis. Abundance of Ku in the cyst cell cytoplasm suggests the role for Ku subunits in the regulation of sperm individualization.
Spatial regulation of exocytosis and cell polarity: Yeast as a model for animal cells
Authors: Brennwald Patrick , Rossi Guendalina
Published: March 2007

Exocytosis is the major mechanism by which new membrane components are delivered to the cell surface. In most, if not all, eukaryotic cells this is also a highly spatially regulated process that is tightly coordinated with the overall polarity of a cell. The Rho/Cdc42 family of GTPases and the lethal giant larvae/Sro7 family are two highly conserved families of proteins which appear to have dual functions both in cell polarity and exocytosis. Analysis of their functions has begun to unravel the coordination between these processes and propose a model for polarized vesicle docking and fusion at the site of asymmetric cell growth.
Versatile retargeting of SH3 domain binding by modification of non‐conserved loop residues
Authors: Hiipakka Marita , Saksela Kalle
Published: March 2007

Src‐homology (SH3) domain belongs to a class of ubiquitous modular protein domains found in nature. SH3 domains have a conserved surface that recognises proline‐rich peptides in ligand proteins, but additional contacts also contribute to binding. Using the SH3 domain of hematopoietic cell kinase as a test case, we show that SH3 binding properties can be profoundly altered by modifications within a hexapeptide sequence in the RT‐loop region that is not involved in recognition of currently known consensus SH3 target peptides. These results highlight the role of non‐conserved regions in SH3 target selection, and introduce a strategy that may be generally feasible for generating artificial SH3 domains with desired ligand binding properties.
The aryl hydrocarbon receptor, more than a xenobiotic‐interacting protein
Authors: Barouki Robert , Coumoul Xavier , Fernandez-Salguero Pedro M.
Published: March 2007

The aryl hydrocarbon (dioxin) receptor (AhR) has been studied for several decades largely because of its critical role in xenobiotic‐induced toxicity and carcinogenesis. Albeit this is a major issue in basic and clinical research, an increasing number of investigators are turning their efforts to try to understand the physiology of the AhR under normal cellular conditions. This is an exciting area that covers cell proliferation and differentiation, endogenous mechanisms of activation, gene regulation, tumor development and cell motility and migration, among others. In this review, we will attempt to summarize the studies supporting the implication of the AhR in those endogenous cellular processes.
T0901317 is a potent PXR ligand: Implications for the biology ascribed to LXR
Authors: Mitro Nico , Vargas Leo , Romeo Russell , Koder Alan , Saez Enrique
Published: March 2007

The liver X receptors (LXRα and β) are nuclear receptors that coordinate carbohydrate and lipid metabolism. Insight into the physiologic roles of the LXRs has been greatly facilitated by the discovery of potent synthetic agonists. Here we show that one of these compounds, T0901317, is also a high‐affinity ligand for the xenobiotic receptor pregnane X receptor (PXR). T0901317 binds and activates PXR with the same nanomolar potency with which it stimulates LXR activity. T0901317 induces expression not only of LXR target genes, but also of PXR target genes in cells and animals, including the scavenger receptor CD36, a property not shared by more specific LXR ligands, such as GW3965. Activation of PXR targets may explain why T0901317 induces dramatic liver steatosis, while GW3965 has a milder effect. These results suggest that many of the biological activities heretofore associated with LXR activation may be mediated by PXR, not LXR. Since T0901317 has been widely used in animals to study LXR function, the in vivo effects of this compound ascribed to LXR activation should be re‐examined.
Molecular physiology of higher plant sucrose transporters
Authors: Sauer Norbert
Published: March 2007

Sucrose is the primary product of photosynthetic CO2 fixation that is used for the distribution of assimilated carbon within higher plants. Its partitioning from the site of synthesis to different sites of storage, conversion into other storage compounds or metabolic degradation involves various steps of cell‐to‐cell movement and transport. Many of these steps occur within symplastic domains, i.e. sucrose moves passively cell‐to‐cell through plasmodesmata. Some essential steps, however, occur between symplastically isolated cells or tissues. In these cases, sucrose is transiently released into the apoplast and its cell‐to‐cell transport depends on the activity of plasma membrane‐localized, energy dependent, H+‐symporting carrier proteins. This paper reviews the current knowledge of sucrose transporter physiology and molecular biology.
Plant proton pumps
Authors: Gaxiola Roberto A. , Palmgren Michael G. , Schumacher Karin
Published: March 2007

Chemiosmotic circuits of plant cells are driven by proton (H+) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react to their constantly changing environments and at the same time maintain optimal metabolic conditions, the expression, activity and interplay of the pumps generating these H+ gradients have to be tightly regulated. In this review, we will highlight results on the regulation, localization and physiological roles of these H+‐ pumps, namely the plasma membrane H+‐ATPase, the vacuolar H+‐ATPase and the vacuolar H+‐PPase.
A proteasome for all occasions
Authors: Hanna John , Finley Daniel
Published: March 2007

In the ubiquitin‐proteasome system, substrates fated for destruction first acquire covalent modification by ubiquitin, and are subsequently destroyed by the proteasome. Traditionally, 26S proteasomes have been seen as largely uniform in their composition and functional capacity. Accordingly, cells can control proteasome abundance via transcriptional pathways that mediate concerted regulation of all known proteasome genes. However, recent evidence suggests that the proteasome is also subject to subunit‐specific modes of regulation, which serve to alter proteasome function and may generate ensembles of compositionally distinct proteasomes. These modes of proteasome regulation provide varied means to adapt protein degradation pathways to changing conditions in the cell.
Extracellular lipid droplets promote hemozoin crystallization in the gut of the blood fluke Schistosoma mansoni
Authors: Corrêa Soares Juliana B.R. , Maya-Monteiro Clarissa M. , Bittencourt-Cunha Paula R.B. , Atella Geórgia C. , Lara Flávio A. , d’Avila Joana C.P. , Menezes Diego , Vannier-Santos Marcos A. , Oliveira Pedro L. , Egan Timothy J. , Oliveira Marcus F.
Published: March 2007

Hemozoin (Hz) is a heme crystal produced upon hemoglobin digestion as the main mechanism of heme disposal in several hematophagous organisms. Here, we show that, in the helminth Schistosoma mansoni, Hz formation occurs in extracellular lipid droplets (LDs). Transmission electron microscopy of adult worms revealed the presence of numerous electron‐lucent round structures similar to LDs in gut lumen, where multicrystalline Hz assemblies were found associated to their surfaces. Female regurgitates promoted Hz formation in vitro in reactions partially inhibited by boiling. Fractionation of regurgitates showed that Hz crystallization activity was essentially concentrated on lower density fractions, which have small amounts of pre‐formed Hz crystals, suggesting that hydrophilic–hydrophobic interfaces, and not Hz itself, play a key catalytic role in Hz formation in S. mansoni. Thus, these data demonstrate that LDs present in the gut lumen of S. mansoni support Hz formation possibly by allowing association of heme to the lipid–water interface of these structures.
Knockdown of ACAT‐1 reduces amyloidogenic processing of APP
Authors: Huttunen Henri J. , Greco Christopher , Kovacs Dora M.
Published: March 2007

Previous studies have shown that acyl‐coenzyme A:cholesterol acyl transferase (ACAT), an enzyme that controls cellular equilibrium between free cholesterol and cholesteryl esters, modulates proteolytic processing of APP in cell‐based and animal models of Alzheimer's disease. Here we report that ACAT‐1 RNAi reduced cellular ACAT‐1 protein by ∼50% and cholesteryl ester levels by 22% while causing a slight increase in the free cholesterol content of ER membranes. This correlated with reduced proteolytic processing of APP and 40% decrease in Aβ secretion. These data show that even a modest decrease in ACAT activity can have robust suppressive effects on Aβ generation.
The roles of organic anion permeases in aluminium resistance and mineral nutrition
Authors: Delhaize Emmanuel , Gruber Benjamin D. , Ryan Peter R.
Published: March 2007

Soluble aluminium (Al3+) is the major constraint to plant growth on acid soils. Plants have evolved mechanisms to tolerate Al3+ and one type of mechanism relies on the efflux of organic anions that protect roots by chelating the Al3+. Al3+ resistance genes of several species have now been isolated and found to encode membrane proteins that facilitate organic anion efflux from roots. These proteins belong to the Al3+‐activated malate transporter (ALMT) and multi‐drug and toxin extrusion (MATE) families. We review the roles of these proteins in Al3+ resistance as well as their roles in other aspects of mineral nutrition.
K+ channel activity in plants: Genes, regulations and functions
Authors: Lebaudy Anne , Véry Anne-Aliénor , Sentenac Hervé
Published: March 2007

Potassium (K+) is the most abundant cation in the cytosol, and plant growth requires that large amounts of K+ are transported from the soil to the growing organs. K+ uptake and fluxes within the plant are mediated by several families of transporters and channels. Here, we describe the different families of K+‐selective channels that have been identified in plants, the so‐called Shaker, TPK and Kir‐like channels, and what is known so far on their regulations and physiological functions in the plant.
Crystallographic structure of the SH3 domain of the human c‐Yes tyrosine kinase: Loop flexibility and amyloid aggregation
Authors: Martín-García José M. , Luque Irene , Mateo Pedro L. , Ruiz-Sanz Javier , Cámara-Artigas Ana
Published: March 2007

SH3 domains from the Src family of tyrosine kinases represent an interesting example of the delicate balance between promiscuity and specificity characteristic of proline‐rich ligand recognition by SH3 domains. The development of inhibitors of therapeutic potential requires a good understanding of the molecular determinants of binding affinity and specificity and relies on the availability of high quality structural information. Here, we present the first high‐resolution crystal structure of the SH3 domain of the c‐Yes oncogen. Comparison with other SH3 domains from the Src family revealed significant deviations in the loop regions. In particular, the n‐Src loop, highly flexible and partially disordered, is stabilized in an unusual conformation by the establishment of several intramolecular hydrogen bonds. Additionally, we present here the first report of amyloid aggregation by an SH3 domain from the Src family.
The use of chlorhexidine to reduce maternal and neonatal mortality and morbidity in low‐resource settings
Authors: McClure E.M. , Goldenberg R.L. , Brandes N. , Darmstadt G.L. , Wright L.L. ,   for the CHX Working Group
Published: March 2007

Of the 4 million neonatal deaths and 500,000 maternal deaths that occur annually worldwide, almost 99% are in developing countries and one‐third are associated with infections. Implementation of proven interventions and targeted research on a select number of promising high‐impact preventative and curative interventions are essential to achieve Millennium Development Goals for reduction of child and maternal mortality. Feasible, simple, low‐cost interventions have the potential to significantly reduce the mortality and severe morbidity associated with infection in these settings. Studies of chlorhexidine in developing countries have focused on three primary uses: 1) intrapartum vaginal and neonatal wiping, 2) neonatal wiping alone, and 3) umbilical cord cleansing. A study of vaginal wiping and neonatal skin cleansing with chlorhexidine, conducted in Malawi in the 1990s suggested that chlorhexidine has potential to reduce neonatal infectious morbidity and mortality. A recent trial of cord cleansing conducted in Nepal also demonstrated benefit. Although studies have shown promise, widespread acceptance and implementation of chlorhexidine use has not yet occurred. This paper is derived in part from data presented at a conference on the use of chlorhexidine in developing countries and reviews the available evidence related to chlorhexidine use to reduce mortality and severe morbidity due to infections in mothers and neonates in low‐resource settings. It also summarizes issues related to programmatic implementation.
To Suspend or not to Suspend: A Randomised Single Blind Trial of Simple Trapeziectomy Versus Trapeziectomy and Flexor Carpi Radialis Suspension
Authors: FIELD J. , BUCHANAN D.
Published: March 2007

The thumb carpometacarpal joint is the second most common site of osteoarthritis in humans. There are numerous operations for the condition but, perhaps, the commonest is trapeziectomy, sometimes supplemented by a suspension procedure, most commonly using part of the flexor carpi radialis tendon. In order to determine whether there is an advantage to a suspension procedure, or not, 65 patients with Eaton and Glickel Grade III or IV arthritis of the carpometacarpal joint of their thumbs were randomised into either undergoing trapeziectomy alone (with no wiring) or a trapeziectomy with flexor carpi radialis suspension. Patient satisfaction from both operations was similar. There was increased range of movement in the trapeziectomy alone group, but there was no difference in grip or pinch strength. Measurement of the gap on X-ray left by the trapeziectomy was less when trapeziectomy alone was performed.
Exploring new research frontiers in offshoring knowledge and service processes
Authors: Youngdahl William , Ramaswamy Kannan , Verma Rohit
Published: March 2007

This paper provides an introduction to a special issue on the offshoring of service and knowledge work. Brief descriptions are provided for 13 papers that fall into three categories including strategic and organizational issues, global and knowledge supply‐chain issues, and tactical issues. The intent of this special issue was to provide a venue for presenting numerous perspectives on the operational and cross‐disciplinary challenges and opportunities in the area of service and knowledge offshoring.
Timing of surficial process changes down a Mojave Desert piedmont
Authors: Nichols Kyle K. , Bierman Paul R. , Eppes Martha C. , Caffee Marc , Finkel Robert , Larsen Jennifer
Published: March 2007

We measured 10Be and 26Al in 29 sediment samples to infer the history and millennial-scale rates of change down a low-gradient piedmont, a common but enigmatic landform that dominates the Mojave Desert. Nuclide data suggest that a large volume of sediment was deposited on the proximal East Range Road piedmont in Fort Irwin, California, ∼ 75,500 yr ago. Since then, this material has been stable or eroding slowly. In contrast, on the distal piedmont (3.5 km from the upland source basins) soil stratigraphy suggests that there have been alternating periods of surface stability, erosion, and deposition over the last 70,000 yr. Nuclide data from samples amalgamated along cross-piedmont transects suggest that long-term average down-gradient sediment speeds range from 9 cm yr− 1 near the uplands to 22 cm yr− 1 6 km down-piedmont. These speeds are similar to 10Be-estimated sediment speeds down three other piedmonts in the Mojave Desert, suggesting that piedmont surface morphologies dominated by shallow migrating channels have similar sediment transport rates. The timing of surface process change down the East Range Road piedmont is determined by a combination of sediment available in the source basins, sediment transport rates, and the size of the piedmont.
Rhetorical Indios: Propagandists and Their Publics in the Spanish Philippines
Authors: Lahiri Smita
Published: April 2007

Censorship notwithstanding, the final half-century of Spanish rule in the Philippines was a time of efflorescence in colonial print culture. Between the advent of typo-lithography in 1858 and the successive occurrence, in 1896 and 1898, of the Filipino revolution and the Spanish-American War, printing presses operating in Manila and beyond issued thousands of books and periodicals, the first public library, the Muséo-Bibliotéca de Filipinas, opened its doors in 1887, and the importation of books from Europe and America could scarcely keep pace with demand.
Social Cohesion (‘Asabiyya) and Justice in the Late Medieval Middle East
Authors: Darling Linda T.
Published: April 2007

The historian Ibn Khaldun (d. 1405), in his Muqaddimah (Introduction to history), explained historical change and the succession of dynasties as a function of the interactions between nomadic culture and urban civilization. His major contribution is usually considered to be his analysis of the correlation between ‘asabiyya, social cohesion or group feeling, and political power. He argued that the strong group feeling of tribal peoples enabled them to conquer urbanized regions and build regimes and civilizations, but that these conquests were undone by the tribes' gradual loss of ‘asabiyya in the urban setting, leading to new conquests by tribal peoples still strong in desert cohesiveness. Although power was the basis of rulership and royal authority was established through military might, the glue that held societies together was ‘asabiyya, based on kinship and religion and stronger in tribal than in urban society. Conquerors with strong group feeling could create greater and longer-lasting empires because they fielded larger armies and retained their own cultural dynamism for a longer time, and thus were able to defeat their rivals. Conquerors whose social cohesion was weak were soon overcome by the civilization of the conquered and gave way to a new conquering group. Strong group cohesion would also allow royal authority to pass to a second branch of the ruling family if the first was weakened, perpetuating its dominion. The ruler and his army were supported by the wealth of conquest, and returned the people's taxes in the form of gifts and public works. They would be successful only so long as they remained just; as the rulers' level of luxury increased so did their level of exploitation, and injustice soon produced division and “the ruin of civilization.”
Galilee as Laboratory: Experiments for New Testament Historians and Theologians
Authors: FREYNE SEAN
Published: April 2007

This paper discusses ways in which NT scholarship can engage meaningfully with contemporary studies in Greco-Roman culture, using recent archaeological exploration in Galilee as samples of such a strategy. Three examples are discussed, dealing respectively with aspects of Hellenisation, Judaisation and Romanisation of the region. These illustrate how specific finds can be brought into dialogue with the literary evidence, providing fresh readings. Such approaches, which recall earlier debates between the Religionsgeschichtliche Schule and the Biblical Theology Movement, raise the issue of how NT scholarship can still be regarded as theological in its aims and objectives. Some tentative answers to this perennial question are offered by way of conclusion.
When memorized instances compete with rules: The case of number-noun agreement in written French
Authors: LARGY PIERRE , COUSIN MARIE-PAULE , BRYANT PETER , FAYOL MICHEL
Published: April 2007

It is claimed by Totereau, Thévenin & Fayol (1997) that French children understand the rule for spelling the plural inflection very early on. However, no evidence contradicts the alternative that they learn the spelling of a word's singular and plural forms by treating the two forms as entirely different words. We tested this by asking French first and second graders (85 six-year-old and 89 seven-year-old children, respectively) to read and write rare words, either in just the singular or in just the plural, and then testing their spelling. The children tended to attach plural inflections to words which they had encountered only as plural and to omit them from words encountered before only as singular.
Intraseasonal variability of Indian Ocean sea surface temperature during boreal winter: Madden‐Julian Oscillation versus submonthly forcing and processes
Authors: Han Weiqing , Yuan Dongliang , Liu W. Timothy , Halkides D. J.
Published: April 2007

Intraseasonal variability of Indian Ocean sea surface temperature (SST) during boreal winter is investigated by analyzing available data and a suite of solutions to an ocean general circulation model for 1998–2004. This period covers the QuikSCAT and Tropical Rainfall Measuring Mission (TRMM) observations. Impacts of the 30–90 day and 10–30 day atmospheric intraseasonal oscillations (ISOs) are examined separately, with the former dominated by the Madden‐Julian Oscillation (MJO) and the latter dominated by convectively coupled Rossby and Kelvin waves. The maximum variation of intraseasonal SST occurs at 10°S–2°S in the wintertime Intertropical Convergence Zone (ITCZ), where the mixed layer is thin and intraseasonal wind speed reaches its maximum. The observed maximum warming (cooling) averaged over (60°E–85°E, 10°S–3°S) is 1.13°C (−0.97°C) for the period of interest, with a standard deviation of 0.39°C in winter. This SST change is forced predominantly by the MJO. While the MJO causes a basin‐wide cooling (warming) in the ITCZ region, submonthly ISOs cause a more complex SST structure that propagates southwestward in the western‐central basin and southeastward in the eastern ocean. On both the MJO and submonthly timescales, winds are the deterministic factor for the SST variability. Short‐wave radiation generally plays a secondary role, and effects of precipitation are negligible. The dominant role of winds results roughly equally from wind speed and stress forcing. Wind speed affects SST by altering turbulent heat fluxes and entrainment cooling. Wind stress affects SST via several local and remote oceanic processes.
A technique for the morphological characterization of submarine landscapes as exemplified by debris flows of the Storegga Slide
Authors: Micallef Aaron , Berndt Christian , Masson Douglas G. , Stow Dorrik A. V.
Published: April 2007

In comparison to subaerial and planetary landscapes, submarine environments are rarely investigated using quantitative geomorphological techniques. Application of traditional geomorphometric techniques is hindered by the spatial variability in bathymetric data resolution and the extensive scale over which changes in topography occur. We propose a novel methodology for the improved quantitative analysis of submarine elevation data by adapting numerical techniques, developed for subaerial analyses, to submarine environments. The method integrates three main morphometric techniques: (1) morphometric attributes and their statistical analyses, (2) feature‐based quantitative representation, and (3) automated topographic classification. These techniques allow useful morphological information to be extracted from a digital elevation model. Morphometric attributes and their statistical analyses provide summary information about an area, which can be used to calibrate computer‐generated geomorphometric maps. In these maps the boundaries of geomorphological features are delineated, and they can thus be used as the basis for geomorphological interpretation. Ridge patterns and their morphological characteristics provide an accurate representation of specific aspects of terrain variability. Moment statistics are used as proxies of surface roughness to differentiate between surface types. Unsupervised classification, carried out using ridge characteristics and moment statistics, reliably segments the surface into units of homogeneous topography. A case study of debris flow lobes within the Storegga Slide shows that the techniques work robustly and that the new methodology integrating all the techniques can significantly enhance submarine geomorphological investigations.
Störmer theory applied to magnetic spacecraft shielding
Authors: Shepherd S. G. , Kress B. T.
Published: April 2007

The existence of a toroidal region from which charged particles are excluded was demonstrated by Störmer (1955) for a dipole magnetic field geometry. Using a standard numerical code to trace the trajectories of particles in a magnetic field, we find excellent agreement with the predicted region for a variety of particle energies and masses. The ability of magnetic fields to shield certain regions from energetic particles, such as galactic cosmic rays (GCRs), has led to the suggestion that certain magnetic field configurations could be used to shield the occupants of a spacecraft from the harmful effects of GCRs during interplanetary space travel. In particular, systems involving a deployed superconducting coil of wire that extends well beyond the dimensions of the spacecraft have been proposed as a viable solution to shielding GCRs. The correct use of the analysis by Störmer (1955) requires that the radius of such a coil be much smaller than the dimension of the region being shielded. Alternatively, it is shown that the energy of the particles shielded from a given region decreases as the radius of a coil with a constant magnetic moment increases. The reality is that large magnetic fields, and thus currents, are necessary to adequately shield GCRs, neither of which are provided by deployed magnetic shields.
East‐west asymmetry in coronal mass ejection geoeffectiveness
Authors: Siscoe G. , MacNeice P. J. , Odstrcil D.
Published: April 2007

This paper extends the domain of applicability of the Gosling‐McComas space weather forecast rule that applies to the postshock sheaths of fast coronal mass ejections at Earth (ICMEs). The rule is based on the draping of the sheath magnetic field around the ICME body. The original treatment considered only the radial‐from‐the‐Sun component of the preshock interplanetary magnetic field (IMF), which implied that the domain of applicability of the rule was the entire sheath region ahead of the leading face of the ICME. We show here that because of the generally prevailing Parker spiral orientation of the IMF, the domain of applicability of the rule is instead generally strongly shifted to the east side of the ICME sheath. We suggest that the eastward shift of the domain of applicability of the rule accounts for an observed greater geoeffectiveness of west hemisphere CMEs compared with east hemisphere CMEs. The approach used here to demonstrate the eastward shift of the region of potential ICME sheath geoeffectiveness, and thus to increase the accuracy of the forecast rule, is to present intensity contours of the geoeffective draping component of the IMF as computed by global MHD simulations. Since the shift depends only on a spiral magnetic field and a blunt object to drape it around, we demonstrate the generality of the principle on which the rule is based by treating both the case of the ICME and the case of Earth's magnetosphere.
Spin sprayed Ni(–Zn)–Co ferrite films with natural resonance frequency exceeding 3GHz
Authors: Kondo Koichi , Yoshida Shigeyoshi , Ono Hiroshi , Abe Masanori
Published: April 2007

Magnetic films having in the gigahertz range high real permeability μ′ and yet exhibiting weak imaginary permeability μ″ (thus low in tanδ=μ″∕μ′) are in great need recently, for use in next-generation magnetic devices such as radio frequency identification (RFID) tags utilizing 900MHz or 2.45GHz band. In this study we successfully prepared films (composition: Ni0.23±0.01ZnxCoyFe2.76±0.01−x−y, x=0–0.34 and y=0.23–0.27) which exhibit such highly capable complex permeability spectra. They were prepared from an aqueous solution at 90°C by spin spray ferrite plating. The films are very low in magnetic losses, having tanδ=0.05–0.14 even at 900MHz, because they have high natural resonance frequencies, fr=3.3–5.4GHz. The tanδ is much lower than that (>0.4) observed for composite-type magnetic sheets at 900MHz. Transmission characteristics of 900MHz band RFID tags were prominently improved by placing the ferrite films of 3μm thickness on the tags.
Statistical temperature molecular dynamics: Application to coarse-grained β-barrel-forming protein models
Authors: Kim Jaegil , Straub John E. , Keyes Thomas
Published: April 2007

Recently the authors proposed a novel sampling algorithm, “statistical temperature molecular dynamics” (STMD) [J. Kim et al., Phys. Rev. Lett. 97, 050601 (2006)], which combines ingredients of multicanonical molecular dynamics and Wang-Landau sampling. Exploiting the relation between the statistical temperature and the density of states, STMD generates a flat energy distribution and efficient sampling with a dynamic update of the statistical temperature, transforming an initial constant estimate to the true statistical temperature T(U), with U being the potential energy. Here, the performance of STMD is examined in the Lennard-Jones fluid with diverse simulation conditions, and in the coarse-grained, off-lattice BLN 46-mer and 69-mer protein models, exhibiting rugged potential energy landscapes with a high degree of frustration. STMD simulations combined with inherent structure (IS) analysis allow an accurate determination of protein thermodynamics down to very low temperatures, overcoming quasiergodicity, and illuminate the transitions occurring in folding in terms of the energy landscape. It is found that a thermodynamic signature of folding is significantly suppressed by accurate sampling, due to an incoherent contribution from low-lying non-native IS in multifunneled landscapes. It is also shown that preferred accessibility to such IS during the collapse transition is intimately related to misfolding or poor foldability.
New method to analyze simulations of activated processes
Authors: Wedekind Jan , Strey Reinhard , Reguera David
Published: April 2007

We present a new method to analyze molecular and Brownian dynamics simulations of activated processes based on the concept of mean first-passage times. The new method provides a simple and efficient strategy to evaluate reaction rates and it facilitates the localization of the transition state directly from the kinetics of the system without the need of thermodynamical considerations. It also provides a more rigorous value of the steady-state transition rate and gives valuable information about many important characteristics of the process. We illustrate the power of this new technique by its application to the study of nucleation in rare gases.
Step coverage modeling of thin films in atomic layer deposition
Authors: Kim Ja-Yong , Ahn Ji-Hoon , Kang Sang-Won , Kim Jin-Hyock
Published: April 2007

A film growth model on microfeatures is proposed to evaluate step coverage depending on precursor injection time in atomic layer deposition. The proposed model is based on that the chemisorption rate of precursors at a certain position along the depth of a microfeature is determined by the total flux of precursors and the sticking probability. The total flux includes the flux coming from the entrance of a microfeature and the flux reflected from other positions inside a microfeature, and the sticking probability depends on the surface coverage of chemisorbed precursor, which is a function of precursor injection time. The proposed model was applied to the deposition of Al2O3 films on 0.3μm diameter holes with an aspect ratio of 10. It was confirmed that the experimental data for step coverage depending on precursor injection time follow the trend predicted by the proposed model.
Hydrodynamic tensor density functional theory with correct susceptibility
Authors: Ovchinnikov Igor V. , Bartell Lizette A. , Neuhauser Daniel
Published: April 2007

In a previous work the authors developed a family of orbital-free tensor equations for the density functional theory [J. Chem. Phys. 124, 024105 (2006)]. The theory is a combination of the coupled hydrodynamic moment equation hierarchy with a cumulant truncation of the one-body electron density matrix. A basic ingredient in the theory is how to truncate the series of equation of motion for the moments. In the original work the authors assumed that the cumulants vanish above a certain order (N). Here the authors show how to modify this assumption to obtain the correct susceptibilities. This is done for N=3, a level above the previous study. At the desired truncation level a few relevant terms are added, which, with the right combination of coefficients, lead to excellent agreement with the Kohn-Sham Lindhard susceptibilities for an uninteracting system. The approach is also powerful away from linear response, as demonstrated in a nonperturbative study of a jellium with a repulsive core, where excellent matching with Kohn-Sham simulations is obtained, while the Thomas-Fermi and von Weiszacker methods show significant deviations. In addition, time-dependent linear response studies at the new N=3 level demonstrate the author’s previous assertion that as the order of the theory is increased new additional transverse sound modes appear mimicking the random phase approximation transverse dispersion region.
Hole distribution and local structure in La2−xSrxCuO4
Authors: Tang F. L. , Zhang X.
Published: April 2007

Atomistic simulation has been performed on La2−xSrxCuO4 to investigate its hole distribution and local structure in real space lattice. It is found that the holes introduced by Sr doping are more energetically favorable to form stripes than to be disordered. The authors verify two types of hole-stripe models (vertical and diagonal domain walls) and propose some other possible types of hole-stripe models, which are quarter or half filled. The local structure of hole stripes is found to be different from the average structure. Sr2+ ions are also found to have a thermodynamics tendency of ordering.
Ni
∕
Au
Ohmic contacts to p-type Mg-doped CuCrO2 epitaxial layers
Authors: Lim W. T. , Stafford L. , Sadik P. W. , Norton D. P. , Pearton S. J. , Wang Y. L. , Ren F.
Published: April 2007

Ohmic contact formation on p-type Mg-doped CuCrO2 layers grown by pulsed-laser deposition was investigated. While the current-voltage characteristics from Ti∕Au contacts showed back-to-back Schottky behavior, a specific contact resistance of ∼1×10−4Ωcm2 was achieved by using Ni instead of Ti. The contact resistivity was fairly independent of measurement temperature, suggesting that tunneling is the dominant transport mechanism. The contact resistance remained practically constant upon annealing in the 100–400°C range. Above 500°C, the morphology became rough and the contact showed rectifying behavior. This degradation resulted from both the out-diffusion of oxygen and the in-diffusion of Ni and Au in CuCrO2.
Enhancement of ballistic transport in an AlGaAs∕InGaAs high electron mobility transistor at low temperatures
Authors: Kim Nambin , Kim Yongmin , Kang Soohyun , Jung Kyooho , Jung Woong , Im Hyunsik , Kim Hyungsang , Rhee J.-K. , Shin Donghoon
Published: April 2007

The authors investigated the current-voltage characteristics of a 100nm AlGaAs∕InGaAs pseudomorphic high electron mobility transistor as a function of temperature. The drain current in the linear region showed a dramatic increase when the temperature was lowered below a critical value (TB) and the drain voltage is increased. A quantitative analysis based on self-consistent Schrödinger-Poisson and simple electrostatic band potential profile calculations was performed to model the transmission coefficient. The modeled results are consistent with the measured data, confirming that the main transport mechanism switches from a classical drift-diffusion transport into a quasiballistic transport when decreasing temperature below TB and increasing drain voltage.
Near-field microwave probe for local ferromagnetic resonance characterization
Authors: Mircea Dragos I. , Clinton T. W.
Published: April 2007

A local ferromagnetic resonance (FMR) technique using a thin-film microwave probe fabricated on coaxial transmission line is presented. Some key features of this probe are its micron-scale size coupled with broadband FMR characterization and mobility: a small area of any location on a magnetic medium can be probed. Permeability of Permalloy (Py) films has been measured, where the authors extract physical parameters, such as FMR frequency, anisotropy field, damping, and spin wave exchange constant, in excellent agreement with independent measurements. Samples of arbitrary shape and size can be measured with a spatial resolution that scales with the size of the probe “tip.”