bluuebunny/crossref_metadata_2025 huggingface dataset:
Short‐term to decadal‐scale onshore bar migration and shoreline changes in the vicinity of a megatidal ebb delta
Authors: Robin Nicolas , Levoy Franck , Monfort Olivier , Anthony Edward
Published: December 2009

Swash bar development has been well documented from coasts with low to moderate tidal ranges, while studies of the effects of these forms on the morphology and dynamics of the adjacent shore in large tide range environments are rare. The analysis of sequential vertical aerial photographs was combined with field work in order to highlight the effects of swash bar development on the adjacent shoreline in the vicinity of a megatidal inlet (mean spring tidal range of 11 m). Swash bars are observed to form on the ebb tidal delta and to migrate landward before welding onto the coast. A close relationship was noticed between the position of the swash bar and shoreline dynamics. The bar protects the shore against wave attack in a sedimentary system controlled by longshore transport. This protective role is, however, modulated by the large tidal range. As the bar migrates upward toward the high‐tide level and the subaerial beach, it develops morphologically into a transverse form that acts as a cross‐shore obstacle to longshore sediment transport, thus resulting in shoreline accretion updrift and in strong erosion downdrift. This disturbance may persist for years because of the relatively slow speed of movement of the bar at this stage, an aspect characteristic of large tide range environments. This pattern of behavior differs fundamentally from that documented in the literature where the perturbation of the longshore sediment transport occurs over shorter periods. An original conceptual model of swash bar morphodynamics and repercussions on the adjacent shoreline for this megatidal environment is proposed.
Impacts of Andean uplift on the Humboldt Current system: A climate model sensitivity study
Authors: Sepulchre Pierre , Sloan Lisa C. , Snyder Mark , Fiechter Jerome
Published: December 2009

Using both an atmospheric global circulation model and a regional oceanic model, we assess the impact of the Andes uplift on the Humboldt Current system (HCS). With three topographic scenarios for the Andes, we show that the uplift played a crucial role in shaping the lower troposphere dynamics over the Pacific Ocean and in turn affected the physical characteristics of the system. Our results show that the uplift has triggered a marked southward shift of the HCS, changing the latitudinal position of coastal upwelling areas as well as the strength of the South Pacific gyre. Our oceanic modeling experiments show that the latitudinal pattern of sea surface temperatures is dramatically modified with reduced Andes, with anomalies reaching up to 3°C. We discuss the feedbacks of these changes on South American climate as well as the potential onset of an altitudinal threshold that would have had triggered these changes.
Caspase cleavage of Ets-1 p51 generates fragments with transcriptional dominant-negative function
Authors: Choul-Li Souhaila , Leroy Catherine , Leprivier Gabriel , Laitem Clélia , Tulasne David , Aumercier Marc
Published: December 2009

Ets-1 is a transcription factor that plays an important role in various physiological and pathological processes, such as development, angiogenesis, apoptosis and tumour invasion. In the present study, we have demonstrated that Ets-1 p51, but not the spliced variant Ets-1 p42, is processed in a caspase-dependent manner in Jurkat T-leukaemia cells undergoing apoptosis, resulting in three C-terminal fragments Cp20, Cp17 and Cp14 and a N-terminal fragment, Np36. In vitro cleavage of Ets-1 p51 by caspase 3 produces fragments consistent with those observed in cells undergoing apoptosis. These fragments are generated by cleavage at three sites located in the exon VII-encoded region of Ets-1 p51. This region is absent from the Ets-1 p42 isoform, which therefore cannot be cleaved by caspases. In Ets-1 p51, cleavage generates C-terminal fragments containing the DNA-binding domain, but lacking the transactivation domain. The Cp17 fragment, the major cleavage product generated during apoptosis, is devoid of transcriptional activity and inhibits Ets-1 p51-mediated transactivation of target genes by competing with Ets-1 p51 for binding to Ets-binding sites present in the target promoters. In the present study, we have demonstrated that caspase cleavage of Ets-1 within the exon VII-encoded region leads to specific down-regulation of the Ets-1 p51 isoform during apoptosis. Furthermore, our results establish that caspase cleavage generates a stable C-terminal fragment that acts as a natural dominant-negative form of the full-length Ets-1 p51 protein.
GaMnAs-based magnetic tunnel junctions with an AlMnAs barrier
Authors: Ohya Shinobu , Muneta Iriya , Hai Pham Nam , Tanaka Masaaki
Published: December 2009

We investigate the spin-dependent transport of GaMnAs-based magnetic tunnel junctions (MTJs) containing a paramagnetic AlMnAs barrier with various thicknesses. The barrier height of AlMnAs with respect to the Fermi level of GaMnAs is estimated to be 110 meV. We observe tunneling magnetoresistance (TMR) ratios up to 175% (at 2.6 K), which is higher than those of the GaMnAs-based MTJs with other barrier materials in the same temperature region. These high TMR ratios can be mainly attributed to the relatively high crystal quality of AlMnAs and the suppression of the tunneling probability at the in-plane wave vector k∥∼0.
Size-dependent magnetic properties and Raman spectra of La2NiMnO6 nanoparticles
Authors: Zhao Shuangyi , Shi Lei , Zhou Shiming , Zhao Jiyin , Yang Haipeng , Guo Yuqiao
Published: December 2009

The structure and magnetic properties of La2NiMnO6 nanoparticles with sizes ranging from about 16 to 66 nm synthesized by a sol-gel method have been investigated. The magnetic measurements reveal that the rates of disordered phases increase as particle size decreases, which can be deduced from the changes of Curie temperature and the occurrence of glasslike behaviors, and the similar saturation magnetization was obtained at 4 K. While the particle size becomes smaller, two broad peaks of Raman spectrum at around 535 and 670 cm−1, which are assigned to antisymmetric stretching mode and symmetric stretching mode, move to higher and lower frequencies than the corresponding modes of the bulk compound, respectively. The two peaks also become broader, while the intensity becomes relatively weaker with the decrease in nanoparticle size. All results support that the trend of Mn4++Ni2+→Mn3++Ni3+ bring locally cooperative Jahn–Teller deformation and charge disproportion, and demonstrate that the nanometer effect is a crucial factor to influence the properties of La2NiMnO6.
Improved spatial resolution for reflection mode infrared microscopy
Authors: Bechtel Hans A. , Martin Michael C. , May T. E. , Lerch Philippe
Published: December 2009

Standard commercial infrared microscopes operating in reflection mode use a mirror to direct the reflected light from the sample to the detector. This mirror blocks about half of the incident light, however, and thus degrades the spatial resolution by reducing the numerical aperture of the objective. Here, we replace the mirror with a 50% beamsplitter to allow full illumination of the objective and retain a way to direct the reflected light to the detector. The improved spatial resolution is demonstrated using two different microscopes capable of diffraction-limited resolution: the first microscope is coupled to a synchrotron source and utilizes a single point detector, whereas the second microscope has a standard blackbody source and uses a focal plane array detector.
Analytical formulas for low-fluence non-line-narrowed hole-burned spectra in an excitonically coupled dimer
Authors: Reppert Mike , Naibo Virginia , Jankowiak Ryszard
Published: December 2009

We present exact equations for the low-fluence non-line-narrowed (NLN) nonphotochemical hole-burning (NPHB) spectrum of an excitonically coupled dimer (for arbitrary coupling strength) under the assumption that postburn and preburn site energies are independent. The equations provide a transparent view into the contributions of various effects to the NPHB spectrum. It is demonstrated that the NPHB spectrum in dimers is largely dominated by the statistical reshuffling of site energies and by altered excitonic transition energies of both excitonic states (in contrast with only the lowest state). For comparison of these results with those from larger excitonically coupled systems, the low-fluence NLN NPHB spectrum obtained for the CP47 complex (a 16-pigment core antenna complex of Photosystem II) is also calculated using Monte Carlo simulations. In this larger system it is shown that the NPHB spectra for individual excitonic states are not entirely conservative (although the changes in average oscillator strength for the higher excitonic states are in most cases less than 1%), a feature which we argue is due primarily to reordering of the contributions of various pigments to the excitonic states. We anticipate that a better understanding of NPHB spectra obtained for various photosynthetic complexes and their simultaneous fits with other optical spectra (e.g., absorption, emission, and circular dichroism spectra) will provide more insight into the underlying electronic structures of various photosynthetic systems.
Percolation in polymer-solvent systems: A Monte Carlo study
Authors: Adamczyk Piotr , Polanowski Piotr , Sikorski Andrzej
Published: December 2009

In this study we investigated the percolation in the system containing long flexible polymer chains. The system also contained explicit solvent molecules. The polymer chains were represented by linear sequences of lattice points restricted to a two-dimensional triangular lattice. The Monte Carlo simulations were performed applying the cooperative motion algorithm. The percolation thresholds and the critical exponents of chains and solvent molecules were determined. The influence of the chain length on the percolation was discussed. It was shown that the percolation threshold decreased strongly with the chain length, which is closely connected to changes in chains’ structure with the decreasing polymer concentration. The critical exponent β for all chains under consideration and for solvent molecules was found almost constant and close to the theoretical value 5/36.
Thermal stability and spin-transfer switchings in MgO-based magnetic tunnel junctions with ferromagnetically and antiferromagnetically coupled synthetic free layers
Authors: Yakata Satoshi , Kubota Hitoshi , Sugano Toru , Seki Takayuki , Yakushiji Kay , Fukushima Akio , Yuasa Shinji , Ando Koji
Published: December 2009

We prepared MgO-based magnetic tunnel junctions having a CoFeB/Ru/CoFeB synthetic free layer in which magnetizations of the CoFeB layers were ferromagnetically coupled (F-coupled Sy) or antiferromagnetically coupled (AF-coupled Sy). We studied spin-transfer switchings to evaluate their thermal stability (Δ0=KV/kBT) and intrinsic switching current density (JC0). Although the free layers of two types showed nearly equal JC0, the Δ0 of F-coupled Sy was observed to be twice that of AF-coupled Sy. This difference is attributable to the shape magnetic anisotropy of the free-layer cells. Results show that F-coupled Sy is superior to AF-coupled Sy for memory applications.
Utilisation of bacterial (Rubrivivax gelatinosus) biomass for egg yolk pigmentation
Authors: Polonio Lorrayne Bernegossi , Ponsano Elisa Helena Giglio , Pinto Marcos Franke , Garcia-Neto Manoel
Published: December 2009

The effects of Rubrivivax gelatinosus biomass inclusion in diets of Dekalb White laying hens were assessed. The traits studied were yolk colour, consumer preference and hepatic and renal function. Broken-line regression was used to assess the biomass requirements for yolk colour attributes. Hens were fed one of six experimental diets formulated with the bacterial biomass at 0 (control), 1.5, 3.0, 4.5, 6.0 and 7.5 g/kg into a corn–soybean meal basal feed for 30 days. All tested concentrations of the biomass caused darkening and increased redness of yolks but did not affect yellowness. The yolk colour most preferred by an untrained panel was achieved by inclusion of a dietary biomass of 4.5 g/kg, the same as the requirement for maximum redness. Biochemical and histological analysis indicated an absence of deleterious effects of the product on liver and kidney functions during the study period. These results indicate that R. gelatinosus biomass can be used to increase red yolk pigmentation.
Phylogeny and evolution of male genitalia within the praying mantis genus Tenodera (Mantodea:Mantidae)
Authors: Jensen Dana , Svenson Gavin J. , Song Hojun , Whiting Michael F.
Published: December 2009

The mantis genus Tenodera is composed of several species distributed across Africa, Asia and Australasia, along with recent human introductions to North America. Species of the genus are morphologically similar and utilise equivalent habitats across their distribution. Relationships among these species and the morphological characters used to diagnose them have never been formally tested, leaving authors to disagree as to the species composition of Tenodera. With DNA sequence data from five molecular loci and morphological characters from male genitalia, we reconstructed the phylogeny of Tenodera using multiple optimality criteria. All included species were found to be monophyletic in analyses of the combined data. Tenodera sinensis and T. bokiana were both supported as distinct species recovered in separate clades, resolving confusion as to their placement and classification. Our analysis identified a previously undescribed species of Tenodera collected in India, recovered as sister to T. aridifolia and T. sinensis, and exhibiting distinct male genital morphology. In light of the phylogeny, we characterise for the first time, and investigate the evolution of, the male genitalia, which allowed us to discover several transitions in structural forms. We also consider the connection of these transitions to sexual cannibalism and how this behaviour may have led to rapid evolution of the male genitalia.
Revision of coelotine spiders from Nepal (Araneae:Amaurobiidae)
Authors: Wang Xin-Ping , Martens Jochen
Published: December 2009

Coelotine spiders from Nepal are studied based on collections from the Himalaya Expeditions of J. Martens carried out in the years 1969, 1970, 1973, 1980, 1983, 1988 and 1995. In total, 38 Nepalese species of the genus Draconarius Ovtchinnikov, 1999 are described, including 35 new species. These are: D. beloniforis, sp. nov. (♂), D. bifarius, sp. nov. (♂), D. brevikarenos, sp. nov. (♀), D. capitellus, sp. nov. (♀), D. communis, sp. nov. (♂♀), D. condocephalus, sp. nov. (♂♀), D. confusus, sp. nov. (♂♀), D. contiguus, sp. nov. (♀), D. cylindratus, sp. nov. (♀), D. dapaensis, sp. nov. (♂), D. distinctus, sp. nov. (♂♀), D. dorsicephalus, sp. nov. (♂♀), D. gorkhaensis, sp. nov. (♂♀), D. gurkha (Brignoli, 1976) (♀), D. latiforus, sp. nov. (♀), D. meganiger, sp. nov. (♀), D. microcoelotes, sp. nov. (♀), D. panchtharensis, sp. nov. (♀), D. paraepisomos, sp. nov. (♂♀), D. phulchokiensis, sp. nov. (♀), D. pseudogurkha, sp. nov. (♀), D. pseudomeganiger, sp. nov. (♀), D. sacculus, sp. nov. (♀), D. schawalleri, sp. nov. (♂), D. semicirculus, sp. nov. (♂♀), D. seorsus, sp. nov. (♀), D. simplicifolis, sp. nov. (♀), D. spinosus, sp. nov. (♂♀), D. subconfusus, sp. nov. (♀), D. subepisomos, sp. nov. (♂♀), D. subrotundus, sp. nov. (♀), D. taplejungensis, sp. nov. (♀), D. testudinatus, sp. nov. (♀), D. tinjuraensis, sp. nov. (♂♀), D. tritos, sp. nov. (♂♀), D. volutobursarius, sp. nov. (♂♀), D. wuermlii (Brignoli, 1978) (♀) and D. yadongensis (Hu & Li, 1987) (♂♀). The male is described for the first time for D. yadongensis. The distribution characteristics of Nepalese coelotines are discussed. The phylogenetic relationships of Coelotinae, including Nepalese coelotines and the two recently established coelotine genera, Lineacoelotes Xu, Li & Wang, 2008 and Notiocoelotes Wang, Xu & Li, 2008 from China and South-east Asia, are analysed using the parsimony method. Our research found that coelotines from Nepal are highly diversified and occur in different clades of the tree. The genus Draconarius is not monophyletic. We assigned all the species examined in this study to Draconarius because they are not congeneric with any existing coelotine genus. Their appropriate placement will be further studied in a future phylogenetic analysis using all coelotine species as terminals.
Phylogenetic analysis and taxonomy of the subgenus Gnathopaederus Chapin and related groups of Paederus s.l. (Coleoptera:Staphylinidae:Paederinae)
Authors: Li Xiao-Yan , Zhou Hong-Zhang
Published: December 2009

The paederine genus Paederus s.l. (Coleoptera : Staphylinidae) is a hyperdiverse group of some 500 species worldwide. Although the subtribe Paederina, in which the genus resides, is monophyletic the status of numerous genera and subgenera is questionable and the current classification is likely to be flawed. As part of detailed studies on the paederine fauna of China, we undertook a preliminary morphologically-based phylogenetic analysis to determine the relationships of Paederus (Gnathopaederus) and related subgenera, as a basis for a revision of the subgenus, and as an attempt to provide a better framework for future taxonomic studies on the group as a whole. The analysis was based on 66 adult morphological characters for 30 ingroup taxa, including all six species of P. (Gnathopaederus). The results show that P. (Gnathopaederus) and P. (Paederus), and the genera Megalopaederus, Pachypaederus and Paederidus are monophyletic, and that P. (Eopaederus) and P. (Harpopaederus) are paraphylyetic. However, our analysis did not offer a robust solution to relationships among other clades within Paederus s.l. although it seems clear that Paederus s.l. is not monophyletic with respect to the above genera. The monophyly of P. (Gnathopaederus) is supported by the mandibular basal medial tooth having two cuspids separated dorsoventrally. Based largely on this character state, the definition of the subgenus is refined; six species are recognized, including two new species described from China as follows: P. (G.) daozhenensis, sp. nov. from Guizhou, and P. (G.) jilongensis, sp. nov. from Xizang; three species, P. bursavacua Willers, P. yunnanensis Willers and P. solodovnikovi Willers, are newly assigned to the subgenus according to a revised subgeneric definition. New morphological characters including important secondary sexual characters and sexual dimorphism are described and male genitalia are illustrated for the first time for the type species of the subgenus, P. (G.) szechuanus (Chapin). A key to the six species is presented and the distribution of each species is documented and discussed.
The long-term effects of logging for woodchips on small mammal populations
Authors: Lunney Daniel , Matthews Alison , Eby Peggy , Penn Angela M.
Published: December 2009

Context. Long-term studies are internationally recognised as an essential component of achieving ecologically sustainable forest management with respect to fauna. Aims. This study aimed to assess longer-term responses of small mammals to logging by returning in 1998 to our 1980–83 study sites in south-eastern New South Wales, Australia. Methods. Three age-classes of forest were surveyed: unlogged; 18–19-year-old regrowth; and 26–34-year-old regrowth. Key results. Rattus fuscipes remained affected by logging, and there were significantly fewer R. fuscipes males in logged, north-west-facing sites than at other sites, although the effect was less pronounced in 1998 than in 1980–83. Antechinus agilis females were significantly less numerous in south-east-facing, unlogged forest. This was not expected from the 1980–83 results. Antechinus swainsonii, which had disappeared following a fire in 1980, had returned to the forest by 1998. A. swainsonii females showed a significant preference for south-east-facing slopes and this relationship was consistent between logged and unlogged forest. No members of Mus musculus or Sminthopsis leucopus, which were present in 1980–83, were caught in 1998. Conclusions. As in the 1980s study, the responses of small mammal species to logging history were varied and species specific. Implications. In our study area, we predict that sustained logging for woodchips will continue to deplete its populations of small mammals. This adds to the case for a more robust and sustained approach to researching and managing our forest fauna.
DNA genotypes reveal red fox (Vulpes vulpes) abundance, response to lethal control and limitations of contemporary survey techniques
Authors: Marks Clive A. , Gigliotti Frank , McPhee Steve , Piggott Maxine P. , Taylor Andrea , Glen Al. S.
Published: December 2009

Context. Scat genotyping has not been routinely used to measure fox (Vulpes vulpes) abundance and our study sought to provide a benchmark for further technique development and assessment of field methods.
Aims. This study sought to provide a comparative assessment of some common methods used to determine fox density and contrast their success with scat DNA genotyping.
Methods. DNA recovered from fox scats was used to genotype individual red foxes and determine their abundance at four transects. Population indices were also developed from bait take, scat counts and sand plot tracks using index-manipulation-index (IMI) procedures on the same transects. Known samples of foxes were taken from two treatment transects using cyanide delivered in the M-44 ejector to manipulate the population and to recover foxes at the end of the trial.
Key results. Replicated counts on a 41-km-spotlight transect at the field site before and after the population manipulation had low variance and good correlation (r2 = 0.79, P < 0.01). Scat genotypes revealed 54 foxes in eight days and, when combined with biopsy DNA from recovered foxes, a minimum known to be alive (KTBA) density of between 1.6 and 5 foxes km–1 was calculated for the transects. Overall, 15/30 (50%) of all recovered foxes had not been detected by scat genotyping, 23/53 (49%) of KTBA genotypes were detected only once and 5/54 (9.5%) of foxes were found to have moved between two transects.
Conclusions. At transects where population manipulation occurred, surviving individuals contributed significantly more scats than at the control transects and some individuals were detected at bait stations at a much greater frequency. This strongly suggested that they had contributed disproportionately to some IMI density estimates that were probably influenced by a change in the activity of some individuals rather than changes in population density alone. At one transect, eight foxes were confirmed to be present by spotlight surveys and were detected by scat and KTBA genotypes, yet were undetected by scat, bait station and sand plot indices.
Implications. Scat and other DNA-based survey techniques provide a great deal of information about the identification and movement of individuals and if DNA sampling methods can be made more efficient they have the potential to provide accurate abundance estimates that are independent of the control technique.
Field-based evaluation of scat DNA methods to estimate population abundance of the spotted-tailed quoll (Dasyurus maculatus), a rare Australian marsupial
Authors: Ruibal Monica , Peakall Rod , Claridge Andrew , Firestone Karen
Published: December 2009

Context. DNA extracted non-invasively from remotely collected scat samples has been used successfully to enumerate populations of a few endangered mammal species. However, scat DNA surveys relying on scent-marking behaviours need to identify if age- or sex-specific variations or seasonal changes in scat scent-marking patterns affect population estimates. Furthermore, owing to the low quantity and quality of scat DNA, a thorough assessment of the technique is needed when it is applied to different species to ensure that individual identification is reliable. Aims. In the current study, microsatellite genetic profiles derived from 208 remotely collected scats of the spotted-tailed quoll (Dasyurus maculatus), a rare Australian marsupial carnivore, were compared with DNA profiles from tissue of 22 live-trapped individuals from the same study area to critically assess the reliability of the non-invasive method to estimate population abundance. Methods. Scat samples were collected at scent-marking sites over 4 consecutive months (April–July 2005), 7 weeks of which overlapped with the trapping program to allow direct comparisons of population estimates. Key results. Combining a multiple-tubes approach with error checking analyses provided reliable genetic tags and resulted in the detection of the majority of the live-trapped population (18 of 22 individuals). Ten additional individuals not known from trapping were also observed from scat DNA. A longer-term sampling regime was required for scats than for trapping to allow direct detection of a large proportion of the population and to provide a comparable population estimate. Critically, the 4-month scat collection period highlighted the importance of performing scat surveys during the mating season when scat scent marking is more frequent, and to avoid sex and age biases in scat marking patterns. Implications. Non-invasive scat DNA sampling methods that rely on scent-marking behaviours need to consider the duration of the sampling period and temporal differences in behaviours by the sexes and age groups to ensure that meaningful population estimates are achieved.
Conditioned taste aversion reduces fox depredation on model eggs on beaches
Authors: Maguire Grainne S. , Stojanovic Dejan , Weston Michael A.
Published: December 2009

Context. Conditioned taste aversion (CTA) is induced by an association of a food item with a negative experience, such as illness, which causes animals to avoid subsequent consumption of that particular food item. Inducing CTA may help reduce depredation rates of threatened fauna where predator population control is undesirable, impractical or unsuccessful.
Aims. We investigated whether CTA could be induced among foxes (Vulpes vulpes) to model eggs which mimicked those of the threatened hooded plover (Thinornis rubricollis).
Methods. Model eggs treated with a potential CTA-inducing chemical (sodium carbonate) and control eggs free of the agent were exposed to fox depredation for 28 days to simulate a hooded plover incubation period. To investigate whether CTA would persist in wild foxes, we implemented a part-time agent treatment (an initial 14 day exposure period of model eggs with the CTA agent followed by a second 14 day period when model eggs were free of the agent).
Key results. Similar intervals to the first depredation event were found for all model eggs regardless of treatment. After the first depredation event by foxes, the rate and likelihood of fox depredation was significantly lower in treated eggs than in control eggs. The likelihood or rate of depredation across the three treatments did not differ between the first and second periods.
Conclusions. Our results suggest that during an exposure period of at least 28 days, CTA can be induced in wild foxes to eggs on beaches. Our results also suggest that 14 days may be insufficient time for wild foxes to develop a lasting CTA to familiar food items such as eggs.
Implications. Treatment of eggs with a CTA-inducing chemical may present a viable alternative to traditional predator control techniques for hooded plovers, as well as other ground-nesting birds, provided that an extended exposure to the CTA-inducing agent occurs.
Quantifying cellular traction forces in three dimensions
Authors: Maskarinec Stacey A. , Franck Christian , Tirrell David A. , Ravichandran Guruswami
Published: December 2009

Cells engage in mechanical force exchange with their extracellular environment through tension generated by the cytoskeleton. A method combining laser scanning confocal microscopy (LSCM) and digital volume correlation (DVC) enables tracking and quantification of cell-mediated deformation of the extracellular matrix in all three spatial dimensions. Time-lapse confocal imaging of migrating 3T3 fibroblasts on fibronectin (FN)-modified polyacrylamide gels of varying thickness reveals significant in-plane (x, y) and normal (z) displacements, and illustrates the extent to which cells, even in nominally two-dimensional (2-D) environments, explore their surroundings in all three dimensions. The magnitudes of the measured displacements are independent of the elastic moduli of the gels. Analysis of the normal displacement profiles suggests that normal forces play important roles even in 2-D cell migration.
miR-221 overexpression contributes to liver tumorigenesis
Authors: Pineau Pascal , Volinia Stefano , McJunkin Katherine , Marchio Agnès , Battiston Carlo , Terris Benoît , Mazzaferro Vincenzo , Lowe Scott W. , Croce Carlo M. , Dejean Anne
Published: December 2009

MicroRNA (miRNAs) are negative regulators of gene expression and can function as tumor suppressors or oncogenes. Expression patterns of miRNAs and their role in the pathogenesis of hepatocellular carcinoma (HCC) are still poorly understood. We profiled miRNA expression in tissue samples (104 HCC, 90 adjacent cirrhotic livers, 21 normal livers) as well as in 35 HCC cell lines. A set of 12 miRNAs (including miR-21, miR-221/222, miR-34a, miR-519a, miR-93, miR-96, and let-7c) was linked to disease progression from normal liver through cirrhosis to full-blown HCC. miR-221/222, the most up-regulated miRNAs in tumor samples, are shown to target the CDK inhibitor p27 and to enhance cell growth in vitro. Conversely, these activities can be efficiently inhibited by an antagomiR specific for miR-221. In addition, we show, using a mouse model of liver cancer, that miR-221 overexpression stimulates growth of tumorigenic murine hepatic progenitor cells. Finally, we identified DNA damage-inducible transcript 4 (DDIT4), a modulator of mTOR pathway, as a bona fide target of miR-221. Taken together, these data reveal an important contribution for miR-221 in hepatocarcinogenesis and suggest a role for DDIT4 dysregulation in this process. Thus, the use of synthetic inhibitors of miR-221 may prove to be a promising approach to liver cancer treatment.
Embryonic stem cell tumor model reveals role of vascular endothelial receptor tyrosine phosphatase in regulating Tie2 pathway in tumor angiogenesis
Authors: Li Zhe , Huang Hui , Boland Patricia , Dominguez Melissa G. , Burfeind Patricia , Lai Ka-Man , Lin Hsin-Chieh , Gale Nicholas W. , Daly Christopher , Auerbach Wojtek , Valenzuela David , Yancopoulos George D. , Thurston Gavin
Published: December 2009

Inhibiting angiogenesis has become an effective approach for treating cancer and other diseases. However, our understanding of signaling pathways in tumor angiogenesis has been limited by the embryonic lethality of many gene knockouts. To overcome this limitation, we used the plasticity of embryonic stem (ES) cells to develop a unique approach to study tumor angiogenesis. Murine ES cells can be readily manipulated genetically; in addition, ES cells implanted subcutaneously in mice develop into tumors that contain a variety of cell types (teratomas). We show that ES cells differentiate into bona fide endothelial cells within the teratoma, and that these ES-derived endothelial cells form part of the functional tumor vasculature. Using this powerful and flexible system, the Angiopoietin/Tie2 system is shown to have a key role in the regulation of tumor vessel size. Endothelial differentiation in the ES teratoma model allows gene-targeting methods to be used in the study of tumor angiogenesis.
Cross-correlations between volume change and price change
Authors: Podobnik Boris , Horvatic Davor , Petersen Alexander M. , Stanley H. Eugene
Published: December 2009

In finance, one usually deals not with prices but with growth rates
R
, defined as the difference in logarithm between two consecutive prices. Here we consider not the trading volume, but rather the volume growth rate
R̃
, the difference in logarithm between two consecutive values of trading volume. To this end, we use several methods to analyze the properties of volume changes |
R̃
|, and their relationship to price changes |
R
|. We analyze 14,981 daily recordings of the Standard and Poor's (S & P) 500 Index over the 59-year period 1950–2009, and find power-law cross-correlations between |
R
| and |
R̃
| by using detrended cross-correlation analysis (DCCA). We introduce a joint stochastic process that models these cross-correlations. Motivated by the relationship between |
R
| and |
R̃
|, we estimate the tail exponent α̃ of the probability density function
P
(|
R̃
|) ∼ |
R̃
|
−1−α̃
for both the S & P 500 Index as well as the collection of 1819 constituents of the New York Stock Exchange Composite Index on 17 July 2009. As a new method to estimate α̃, we calculate the time intervals τ

q

between events where
R̃
>
q
. We demonstrate that τ̃

q

, the average of τ

q

, obeys τ̃

q

∼
q
α̃
. We find α̃ ≈ 3. Furthermore, by aggregating all τ

q

values of 28 global financial indices, we also observe an approximate inverse cubic law.
Isolation and characterization of centroacinar/terminal ductal progenitor cells in adult mouse pancreas
Authors: Rovira Meritxell , Scott Sherri-Gae , Liss Andrew S. , Jensen Jan , Thayer Sarah P. , Leach Steven D.
Published: December 2009

The question of whether dedicated progenitor cells exist in adult vertebrate pancreas remains controversial. Centroacinar cells and terminal duct (CA/TD) cells lie at the junction between peripheral acinar cells and the adjacent ductal epithelium, and are frequently included among cell types proposed as candidate pancreatic progenitors. However these cells have not previously been isolated in a manner that allows formal assessment of their progenitor capacities. We have found that a subset of adult CA/TD cells are characterized by high levels of ALDH1 enzymatic activity, related to high-level expression of both
Aldh1a1
and
Aldh1a7
. This allows their isolation by FACS using a fluorogenic ALDH1 substrate. FACS-isolated CA/TD cells are relatively depleted of transcripts associated with differentiated pancreatic cell types. In contrast, they are markedly enriched for transcripts encoding
Sca1
,
Sdf1
,
c-Met
,
Nestin
, and
Sox9
, markers previously associated with progenitor populations in embryonic pancreas and other tissues. FACS-sorted CA/TD cells are uniquely able to form self-renewing “pancreatospheres” in suspension culture, even when plated at clonal density. These spheres display a capacity for spontaneous endocrine and exocrine differentiation, as well as glucose-responsive insulin secretion. In addition, when injected into cultured embryonic dorsal pancreatic buds, these adult cells display a unique capacity to contribute to both the embryonic endocrine and exocrine lineages. Finally, these cells demonstrate dramatic expansion in the setting of chronic epithelial injury. These findings suggest that CA/TD cells are indeed capable of progenitor function and may contribute to the maintenance of tissue homeostasis in adult mouse pancreas.
An Assessment of House Staff's Knowledge of Alcohol and Substance Abuse Utilizing Standardized Patients
Authors: Stimmel Barry , Cohen Devra , Colliver Jerry , Swartz Mark
Published: December 2009

Utilizing standardized patients (SPs), house staff knowledge of alcohol and substance abuse was assessed in residents just prior to their starting their first graduate year of training. A total of 345 residents from 13 different residencies in eight institutions participated in this program. Each resident was assigned four SP cases. The reliability of these encounters ranged from 0.63 to 0.74. Of the participating residents, 22% were United States medical graduates (USMGs) and 78% were international medical graduates (IMGs). A considerable proportion of both USMGs and IMGs failed to ask appropriate questions concerning alcohol and drug use or identify the presence of risk factors associated with such use. Residents’ scores on cases primarily dealing with general medical issues, as compared to those dealing with substance abuse, were consistently higher. Knowledge of basic information concerning substance abuse and opioids was deficient in over 50% of those tested. These findings suggest that residents about to start their clinical training are not sufficiently prepared to address patients presenting with alcohol and other drug problems.
Training Community‐Based Clinicians in Screening and Brief Intervention for Substance Abuse Problems: Translating Evidence into Practice
Authors: Saitz Richard , Sullivan Lisa M. , Samet Jeffrey H.
Published: December 2009

Screening and brief intervention in general health care settings are efficacious but have not been widely adopted. Our objective was to assess the effect of an educational intervention on clinicians’ substance abuse‐related clinical practices. The study was a telephone survey of practicing physicians, nurses, psychologists, physician's assistants, and social workers who attended a half‐day continuing education course on one of four occasions. The course covered the stages of behavioral change and motivational counseling, using primarily role play with standardized patients. Of 87 course attendees, 70 (80%) completed the interview. Months to years after the course, most (91%) reported that the course made an impact on their practice. Most (78%) of respondents reported that they frequently or always asked new patients who drank alcohol a formal screening questionnaire such as the CAGE, and 94% frequently or always assessed their substance abusing patients’ readiness to change. Most respondents reported that since taking the course they were more likely (1) to screen patients for alcohol or drug related problems (86%) and (2) to ask patients about their substance abuse on a follow‐up visit (96%). After exposure to an active‐learning half‐day continuing education course, clinicians reported improvement with and high rates of desirable substance abuse‐related clinical practices up to 5 years later. Continuing education efforts that incorporate active learning directed toward practicing clinicians show promise for improving rates of brief intervention for alcohol and other drug abuse.
Chronic Drug Use and Crime
Authors: French Michael T. , McGeary Kerry Anne , Chitwood Dale D. , McCoy Clyde B. , Inciardi James A. , McBride Duane
Published: December 2009

This paper used bivariate and multivariate analyses to estimate the relationships between chronic drug use and various measures of criminal activity. The data for these analyses were derived from the 1993 (1) and 1995 (2) National Household Surveys on Drug Abuse (NHSDA). Measures of criminal justice system contact and criminal activity included ever arrested, arrested during the previous year, commission of a predatory crime (e.g., assault, fighting) during the previous year, and commission of a property crime (e.g., theft, property damage, car theft, breaking and entering) during the previous year. The analysis was conducted separately for males, females, and age groups, and it distinguished between chronic drug users, nonchronic drug users, and nondrug users. The results consistently showed a significant linear relationship between criminal activity and frequency of drug use. These findings have implications regarding the potential reduction in predatory and property crime that could occur from a decrease in drug use. Significant differences in criminal behavior between chronic drug users and other cohorts may signal a critical need to develop targeted interventions for this particular type of drug user.
Computer‐Generated Written Behavioral Contracts with Problem Drinkers in Primary Medical Care
Authors: Vinson Daniel C. , Devera‐Sales Amelia
Published: December 2009

Problem drinking is common among patients in primary medical care, but often unrecognized. Brief physician interventions can be helpful, but several barriers hinder their adoption in practice, notably a lack of time. We conducted a randomized pilot study of written behavioral contracts that patients wrote with help from a computer program. In eight family medicine practices, 2684 patients were approached and 2399 screened with the Alcohol Use Disorders Identification Test (AUDIT). Of those, 186 screened positive, 154 were eligible, and 80 enrolled. Follow‐up interviews were completed with 69 (86%). At 12 months, the AUDIT and Addiction Severity Index alcohol scores decreased nonsignificantly more in the intervention group than in the controls. The study demonstrated that computer‐based interventions are acceptable to patients and physicians, feasible in busy primary care practices, and have effect sizes comparable to those of physician‐based interventions. Computer‐based interventions may be an effective and efficient tool to enhance identification of and intervention with problem drinkers in primary care.
A European Union Concerted Action: Alcohol Consumption and Alcohol Problems Among Women in European Countries
Authors: Bloomfield Kim
Published: December 2009

Traditionally, less research has been conducted on women's drinking as compared to men's. But women's drinking has been shown to differ from men's in terms of consumption patterns and in factors determining heavy and problematic drinking. Thus, special efforts are needed to increase knowledge in this field. This article introduces a set of papers from the recently completed concerted action project “Alcohol Consumption and Alcohol Problems among Women in European Countries, “ supported by the European Commission. The aim of the study was to examine and compare the drinking patterns and problems of women in 9 European countries. This was done by comparing alcohol consumption and alcohol problem rates within and between countries and between men and women and among women. The project also developed recommendations for much needed standardized measures of alcohol consumption and alcohol problems for use in European alcohol epidemiological research.
Women's Roles and Women's Drinking: A Comparative Study in Four European Countries
Authors: Gmel Gerhard , Bloomfield Kim , Ahlström Salme , Choquet Marie , Lecomte Thérèse
Published: December 2009

The present study analyzes the influence of role combinations on heavy drinking in four European countries: Finland, France, Germany, and Switzerland. Data sets come from nationally representative surveys. A growing number of studies have investigated the influence of social roles on alcohol consumption. Different theories such as role accumulation, role overload, and role deprivation aim to explain the association between roles and poor mental health, including heavy alcohol consumption. The results show that roles and role combinations influence heavy drinking differently in each country. The findings also indicate that the social position of women in a country is strongly connected to the differing associations between specific role combinations and heavy drinking across countries. No single role theory can be applied cross‐culturally. Large‐scale surveys are needed to test statistically the association between role combinations and heavy drinking.
Alcohol Consumption Estimates in Surveys in Europe: Comparability and Sensitivity for Gender Differences
Authors: Knibbe Ronald A. , Bloomfield Kim
Published: December 2009

The comparability of general population studies on alcohol from nine European countries is evaluated from three points of view: (1) methodologic aspects influencing alcohol estimates, (2) variation between countries in coverage of sales estimates of alcohol consumption, and (3) associations between type of question used to measure alcohol consumption and gender differences in alcohol consumption. With respect to methodologic aspects, it was found that the studies differed on most of the 10 points included in this comparison. The coverage of sales estimates by surveys varies between 39% (Germany) and 56% (France). With respect to type of question and gender differences, it was found that more elaborate sets of questions on alcohol consumption are associated with smaller gender differences in the prevalence of heavy drinking (>600 g 100% alc/mo). It is concluded that the methodologic differences between studies and the differences in sales coverage do not allow cross–national comparison of survey estimates of alcohol consumption of different European countries. Compared with more elaborate sets of questions on alcohol consumption, simple questions on alcohol consumption are likely to underestimate gender differences in the prevalence of heavier drinking.
Gender Differences in Drinking Patterns in Nine European Countries: Descriptive Findings
Authors: Ahlström Salme , Bloomfield Kim , Knibbe Ronald
Published: December 2009

Gender differences in drinking patterns in nine European countries (the Czech Republic, Finland, France, Germany, Italy, The Netherlands, Scotland, Sweden, and Switzerland) were examined using data from surveys conducted in the late 1980s and early 1990s. Drinking patterns were analyzed with regard to sociodemographic variables such as age, education, employment, marital status, and parenthood. Age was closely related to drinking in every society, but the patterns were different in different societies. Women with higher education tended to consume more alcohol than women with lower education in many societies, whereas a similar pattern was not found among men. Unemployment seemed to be more strongly related to women's drinking than to that of men. Divorced men consistently consumed the most alcohol in every country. Parenthood was profoundly and consistently associated across societies with women's monthly consumption and prevalence of heavy drinking.
Medical Education about the Care of Addicted Incarcerated Persons: A National Survey of Residency Programs
Authors: Kraus Mark L. , Isaacson J. Harry , Kahn Ruth , Mundt Marlon P. , Manwell Linda Baier
Published: December 2009

In June 1998, there were 1.8 million inmates in correctional facilities for adults; 1.2 million in state and federal prisons and 600,000 in municipal/county jails (668 persons per 100,000 U.S. population). Rates of TB, AIDS, mental illness, and substance abuse are 2–13 times higher in persons living in jails and prisons. This study was designed to assess the level of training offered to residents in seven medical specialties in the care of addicted incarcerated persons. The study design involved two stages. The first entailed a mailed survey to 1,831 residency directors in family medicine, internal medicine, osteopathic medicine, pediatrics, obstetrics and gynecology, psychiatry, and emergency medicine. The second stage was a telephone interview, about substance use disorders, of faculty listed by the residency directors as teaching residents. The mailed survey was completed by 1,205 residency directors (66%). The 769 faculty from those identified programs, who participated in the telephone interview, reported that only 14% of their residency programs offered lectures or conferences on the care of incarcerated persons, yet 44% of the programs had residents caring for incarcerated persons with substance abuse problems, in a clinical setting. Only 22% offered clinical experiences for residents in a correctional facility.

We recognize that our survey of correctional health and substance abuse training is limited, but as such, a greater number of respondents to our survey do not teach residents addiction medicine topics pertaining to prevention, evaluation, intervention, and management of the addicted criminal offender/patient in a correctional setting or give adequate clinical exposure to this special population. The data suggests a need to develop and implement educational programs on medical care for this high–risk and expanding population.