bluuebunny/crossref_metadata_2025 huggingface dataset:
AN APULIAN VOLUTE-CRATER INSPIRED BY EURIPIDES' DICTYS
Authors: KARAMANOU IOANNA
Published: March 2010

This paper aims to substantiate the relation of an Apulian vase-painting to a fourth-century revival of Euripides' Dictys. The obverse shows Perseus returning to Seriphos with the Gorgon's head, with Danae and Dictys as suppliants at Poseidon's altar, and king Polydectes. Its dramatic inspiration is suggested by the depiction of characters in stage-costumes, the ‘speaking’ gesture used by Dictys, the conventional aedicula-pattern, and the Dionysiac scene on the reverse. The lack of evidence for Aeschylus' Polydectes implies its reduced popularity, and makes it unlikely to have inspired this vase-painting, as against the reasonable number of quotations from the Dictys and the wide popularity of Euripidean drama in South-Italian pottery. This altar scene confirms that the accounts of Ps. Apollodorus and Theon reflect the plot of the Dictys, and offers evidence for the basic reconstruction of the play.
THE FORMATION OF THE TEXT OF VERGIL — AGAIN
Authors: COURTNEY E.
Published: March 2010

This article resumes one published in this journal in 1981, in which it was argued, on the basis of universal conjunctive errors, that the capital manuscripts of Vergil descend from an archetype. Timpanaro among others argued in response that such errors, where they existed, were due to horizontal transmission. That view is here countered, and some of the passages discussed in 1981 are revisited, as well as some others about which problems have been raised in the meantime (Ecl. 6.61–73, Georg. 4.520–21, Aen. 9.914, 10.366).
CICERO's BRUTUS: THE END OF ORATORY AND THE BEGINNING OF HISTORY?
Authors: STEEL C. E. W.
Published: March 2010

The ostensible function of the Brutus is to record the history of oratory at Rome and thereby confirm that it has ceased to exist under Caesar's dictatorship. But the gulf between Cicero's ideal of oratory and its actual use mean that he is unable to implement his inclusive selection criteria, as the absences of Marius, Sulla, Catiline and Clodius from the catalogue indicate; and his discussions of speakers have to concentrate on technique and not content. And whilst the narrative logic of the work tends towards Cicero himself as the culmination of Roman eloquence, his ultimate failure to inscribe himself into the canon shows that he is not yet willing to withdraw from political activity and cease to be an orator.
CLYTAIMESTRA'S NEGATIVES AND THE FINAL LINE OF AGAMEMNON
Authors: LAVERY JOHN
Published: March 2010

Lines 1672–73 of Agamemnon are lacunose. Various supplements have been proposed. The paper restates the problems with the solutions available to date, and on the basis of the dramatic context, the structure of Clytaimestra's speeches in this section of the play and external evidence for Greek political vocabulary relevant to the political situation in Argos after the murder of Agamemnon offers new readings.
THEOPHRASTUS AND ARISTOXENUS: CONFUSIONS IN MUSICAL METAPHYSICS
Authors: BARKER ANDREW
Published: March 2010

Theophrastus frag. 716 attacks the thesis that differences between musical pitches are quantitative. Most of its fire-power is directed at harmonic theory in the ‘mathematical’ or ‘Pythagorean’ style, but one short passage (lines 108 ff.) is not. Previous commentators have identified its target as Aristoxenus; but I argue that Theophrastus' account does not fit Aristoxenus' position, and that we should look for his target in the work of earlier‘empirical’ theorists. After reviewing and rejecting various possibilities, I tentatively suggest that Theophrastus' conception of the empiricists' standpoint may originate in a plausible but probably mistaken interpretation of Republic 531a-b. I then argue that so far from criticizing Aristoxenus' ideas, Theophrastus' polemic makes substantial use of them. Finally, I explain how this phase of his discussion returns us to the intriguing questions from which his whole anti-quantitative tirade began.
AN OVERLOOKED PAPYRUS OF ISAIOS
Authors: CAREY CHRIS
Published: March 2010

P. Oxy 2538 was tentatively assigned by its first editor to the orator Lysias. This paper argues for attribution to Isaios on grounds of argument and style. It also discusses the nature of the case and explores possible dating.
A Peroxidase/Dual Oxidase System Modulates Midgut Epithelial Immunity in
Anopheles gambiae
Authors: Kumar Sanjeev , Molina-Cruz Alvaro , Gupta Lalita , Rodrigues Janneth , Barillas-Mury Carolina
Published: March 2010

Mosquito Double Act

Peroxidase/dual oxidase (duox) systems act in concert to catalyze the nonspecific formation of dityrosine bonds, which cross-link a variety of proteins. Knowing that these reactions are involved in fine-tuning insect immune responses,

Kumar
et al.

(p.
1644
, published online 11 March) investigated how the peroxidase/duox system in malaria-vector mosquitoes protects the gut flora by modulating midgut antibacterial responses. Generating immune reactions resulted in a loss of mosquito egg viability, but modulating host responses allowed malaria parasites to persist among the surviving commensal flora. The peroxidase/duox system appears to promote dityrosine bond formation between proteins across the surface of midgut epithelial cells to form a layer that inhibits immune recognition and mediator release. Interference with the formation of this layer might provide a target for mosquito and malaria control.
Long-Term Dynamics of Three Crayfish Species in Trout Lake, Wisconsin
Authors: Lodge David M. , Kratz Timothy K. , Capelli Gregory M.
Published: March 2010

Previous reports suggested that crayfish species composition in northern Wisconsin is changing unidirectionally because of the competitive hierarchy of sequential invaders. In Trout Lake, Vilas County, Wisconsin, we expected Orconectes virilis to decline in the presence of O. propinquus and for both to be displaced by O. rusticus. Our data show the abundance and species composition of Orconectes species in Trout Lake have been changing since 1931. A 1932 survey determined that O. virilis was the only Orconectes in Trout Lake. In 1973, we found that O. propinquus was abundant and O. virilis uncommon. Yet between 1973 and 1983 (probably between 1980 and 1983), O. virilis became much more widespread and abundant, while the population of O. propinquus declined. Between 1973 and 1979, O. rusticus invaded the lake, but has remained in low abundance. Both of our predictions are contradicted by our results. Orconectes propinquus has declined and O. virilis has increased, and while O. rusticus has invaded, it has not yet displaced the other species. We suggest that the outcome of interspecific interactions is variable and probably affected by other community structuring forces such as predation, parasitism, and disturbance, in addition to competition.
Fish Antifreeze Proteins: Recent Gene Evolution
Authors: Scott Gary K. , Fletcher Garth L. , Davies Peter L.
Published: March 2010

A variety of antifreeze proteins is produced by marine teleosts inhabiting polar regions to ensure protection from internal ice formation at subzero temperatures. Combining evidence from paleoclimatology, teleostian evolution, and studies of antifreeze gene organization, the case is made for Cenozoic cooling as the force driving antifreeze evolution in marine teleosts. The distribution of antifreeze types amongst teleost suborders, families, genera, and species correlates with Cenozoic glaciation in the Southern Hemisphere preceding that in the Northern Hemisphere by approximately 25 million yr. The genomic organization of antifreeze genes suggests recent and extensive amplification, an event compatible with their proposed stress-induced origin. Also, a realignment of the nototheniids with the Gadiformes based on antifreeze protein data is suggested.
An Empirical Model to Predict in situ Grazing Rates of Diaptomus minutus Lilljeborg on Small Algal Particles
Authors: Chow-Fraser Patricia
Published: March 2010

Grazing rates of Diaptomus minutus were measured in situ in six lakes in south-central Ontario using the tracer species Chlorella vulgaris and Scenedesmus ovalis. An empirical model was constructed to predict grazing rate as a function of the relative proportion of small (<10 μm)to large (10–30 μm) algal particles in the nanoplankton. It accurately predicted diaptomid grazing rates for three lakes in an independent lake set; however, it produced overestimates for two other lakes. There was also a significant positive correlation between grazing rate and the biomass concentration of small algae in the lakes. Difference in ambient lake temperature did not contribute significantly towards explained variation in grazing rate; prosome length was also a poor predictor of grazing rate. In parallel experiments, diaptomid grazing rates were higher when Pediastrum was used than when Scenedesmus was used as the tracer; in a similar set of experiments, grazing rates were higher when Chlamydomonas was used than when Scenedesmus was used.
Changes in Lengths of Fixed and Preserved Young Freshwater Fish
Authors: Leslie J. K. , Moore J. E.
Published: March 2010

The lengths of body parts of several species of young freshwater fish were measured to determine short- and medium-term effects of fixation and preservation. Shrinkage (up to 4.9%) was the rule, but lengths also increased, or remained static; rigor mortis was probably the main cause of immediate change. However, measurement error probably affected precision in the smallest lengths. Body parts changed differentially; these changes were not species specific, nor was type of fixative or preservative significant. Trunk and snout to vent length indicated most susceptibility to change (especially shrinkage); head length was least affected. Changes were considered of little or no practical consequence for taxonomy and growth studies.
A unified approach to densification and liquefaction of cohesionless sand in cyclic shearing
Authors: Nemat-Nasser S. , Shokooh A.
Published: March 2010

When submitted to cyclic shearing, loose dry sand densifies, and undrained saturated sand may liquefy. Based on energy considerations, a unified theory for densification and liquefaction of a homogeneous sample of cohesionless sand is proposed. It is observed that these phenomena involve rearrangement of grains in microscale, requiring an expenditure of a certain amount of energy, which increases as the void ratio approaches its minimum value and decreases as the excess pore water pressure increases. On the basis of rough estimates, explicit relations are developed for both the densification and liquefaction phenomena, and the results are applied to predict relevant available experimental data.
Stabilization of planar landslides in permafrost
Authors: Pufahl D. E. , Morgenstern N. R.
Published: March 2010

A method of stabilizing or inhibiting the occurrence of planar landslides in regions of permafrost, utilizing an insulative material and a free-draining surcharge load, is presented. A measure of the pore pressures considered in the effective stress analysis is determined by assuming steady state seepage parallel to the surface and pore water pressures generated during thaw consolidated due to self-weight and surcharge load. The insulation reduces the rate of thaw and thus the rate of generation of excess pore water pressures, and the surcharge increases the effective normal stress disproportionate to any increase in shearing stress.Different design methods are outlined and a series of design charts is proposed for rapid computation of the required combination of insulation thickness and surcharge load for a range of typical soil and climatic conditions encountered in arctic and subarctic regions.
A laboratory study of tiebacks in cohesive soil
Authors: Boonsinsuk Prapote , Ludwig Harald , Yong Raymond N.
Published: March 2010

The short-term and long-term behaviour of tiebacks anchored in cohesive soils are not well understood, particularly regarding basic component responses of the overall tieback system. There are shortcomings in the predictive capacity for short-term and long-term performances both in individual tiebacks and complete systems. Nevertheless, the methods currently being used to calculate the ultimate resistance to pull-out of individual or groups of tiebacks appear to be conservative.A physical-model laboratory test facility has been designed to investigate the short-term and long-term behaviour of small-scale straight-shafted tiebacks anchored in cohesive soils to provide the following: pore-water pressure measurements, tieback lock-off, measurement of total and residual tieback movement, measurement of load distribution along the tieback, and unearthing of the tieback. The laboratory tieback behaviour has been studied using both consolidated and compacted clay, to indicate the effects of stress history, loading test technique, and overburden pressure on tieback performance. Key words: clay, creep, laboratory tieback test, tieback, soil anchor, consolidation, soil–structure interaction.
The Petrofka landslide, Saskatchewan
Authors: Eckel B. F. , Sauer E. Karl , Christiansen E. A.
Published: March 2010

Both abutments and all piers of the Petrofka bridge are on a landslide. The bridge has performed satisfactorily for 23 years, indicating the factor of safety of the Petrofka landslide is greater than unity. This stability is abnormal because landslide slopes on bedrock clays (shale) in this region are notoriously unstable. A dormant landslide is difficult to analyze because the input parameters must represent a condition of limiting equilibrium.The Petrofka landslide is 70 m high, 880 m long, 3000 m wide, and up to 100 m thick. The shear zone is in highly plastic, montmorillonitic clays in an unnamed formation of probable Tertiary age. The Upper Cretaceous Lea Park, Judith River, and Bearpaw formations and the unnamed formation underly the landslide and are restricted to a collapse structure resulting from dissolution of Devonian evaporites.A retrogressive mechanism developed as valley downcutting progressed. The pore-water pressures could be estimated from the hydraulic head in the artesian aquifer of the Judith River Formation. The hydraulic head was maintained at critical as the valley deepened until the Judith River Formation was eroded downstream. The landslide was active for only a few hundred years, between 11 500 and 11 000 years ago.The back-calculated effective angle of friction for the bedrock clay (shale) was estimated at between 5.6° and 6.5°, assuming c′ = 0, resulting in a present-day factor of safety between 1.2 and 1.3. Key words: back analysis, dormant landslide, collapse structure, artesian pressure, historical simulation, residual shear strength.
THE FIRST AND SECOND VARIATION OF THE TOTAL ENERGY OF CLOSED DUPLEX DNA IN PLANAR CASE
Authors: ZHOU XIAO-HUA
Published: March 2010

DNA's shape mostly lies on its total energy F. Its corresponding equilibrium shape equations can be obtained by classical variation method: letting the first energy variation δ(1)F = 0. Here, we not only provide the first variation δ(1)F but also give the second variation δ(2)F in planar case. Moreover, the general shape equations of DNA are abstained and a mistake in Zhang et al., [Phys. Rev. E70, 051902 (2004)] is pointed out.
ANALYSIS OF NONLINEAR MAGNETOELASTIC DYNAMICS AND STABILITY OF CONDUCTIVE CYLINDRICAL SHELLS
Authors: HU YUDA , ZHAO JIANG , JUN PI , QING GUANGHUI
Published: March 2010

The nonlinear magnetoelastic vibration equations and electromagnetic field equations of a conductive thin cylindrical shell in magnetic fields are derived. The nonlinear principal resonances and dynamic stabilities of the cylindrical shell simply supported in a transverse magnetic field are investigated. Approximate analytical solution and bifurcation equations of the system with principal resonances are obtained by using the method of multiple scales. The stabilities and singularities of the steady-state solutions are analyzed and the stability criterion is given. The transition sets and bifurcation figures of unfolding parameters are also obtained. The variations of the resonance amplitudes with respect to the detuning parameter, the magnetic induction intensity, and the amplitude of excitations are presented. The corresponding phase trajectories in moving phase planes are given. The stabilities of solutions, characteristics of singular points, and bifurcation are analyzed. The impacts of electromagnetic and mechanical parameters on dynamic behaviors are discussed in detail.
DYNAMIC PERFORMANCES OF A RAILWAY BRIDGE UNDER MOVING TRAIN LOAD USING EXPERIMENTAL MODAL PARAMETERS
Authors: KIM SUNG-IL , KIM NAM-SIK
Published: March 2010

In the design of railway bridges, it is necessary to be able to predict their dynamic behavior under a moving train load so as to avoid a resonance state from repetitive moving axle forces with uniform intervals. According to design trends, newly developed girder bridges weigh less and have longer spans. Since the dynamic interaction between bridge superstructures and passing trains is one of the critical issues concerning such railway bridges that are designed with greater flexibility, it is very important to evaluate the modal parameters of newly designed PSC girders before carrying out dynamic analyses. In this paper, a full scale incrementally prestressed 25-meter long concrete girder was fabricated as a test specimen and modal testing was performed at every prestressing stage in order to evaluate the modal parameters, including the natural frequency and the modal damping ratio. Young's modulus was also obtained from the global stiffness of the test specimen. During the modal testing, a digitally controlled vibration exciter and an impact hammer were applied in order to obtain precise frequency response functions, and the modal parameters were evaluated at various construction stages. With the availability of reliable properties from the modal experiments, dynamic performance estimation of a PSC girder railway bridge during the passage of a moving train can be carried out.
THETA SERIES OVER THE HURWITZ QUATERNIONS
Authors: KRIEG ALOYS
Published: March 2010

There are six theta constants over the Hurwitz quaternions on the quaternion half-space of degree 2. The paper describes the behavior of these theta constants under the transpose mapping, which can be derived from the Fourier expansions. The results are applied to the theta series of the first and second kind.
ARITHMETIC TRACES OF NON-HOLOMORPHIC MODULAR INVARIANTS
Authors: MILLER ALISON , PIXTON AARON
Published: March 2010

We extend results of Bringmann and Ono that relate certain generalized traces of Maass–Poincaré series to Fourier coefficients of modular forms of half-integral weight. By specializing to cases in which these traces are usual traces of algebraic numbers, we generalize results of Zagier describing arithmetic traces associated to modular forms. We define correspondences [Formula: see text] and [Formula: see text]. We show that if f is a modular form of non-positive weight 2 - 2 λ and odd level N, holomorphic away from the cusp at infinity, then the traces of values at Heegner points of a certain iterated non-holomorphic derivative of f are equal to Fourier coefficients of the half-integral weight modular forms [Formula: see text].
VEGF in the lung: a role for novel isoforms
Authors: Varet Julia , Douglas Samantha K. , Gilmartin Laura , Medford Andrew R. L. , Bates David O. , Harper Steven J. , Millar Ann B.
Published: March 2010

Vascular endothelial cell growth factor (VEGF) is a potent mitogen and permogen that increases in the plasma and decreases in the alveolar space in respiratory diseases such as acute respiratory distress syndrome (ARDS). This observation has led to controversy over the role of this potent molecule in lung physiology and disease. We hypothesized that some of the VEGF previously detected in normal lung may be of the anti-angiogenic family (VEGFxxxb) with significant potential effects on VEGF bioactivity. VEGFxxxb protein expression was assessed by indirect immunohistochemistry in normal and ARDS tissue. Expression of VEGFxxxb was also detected by immunoblotting in normal lung tissue, primary human alveolar type II (ATII) cells, and bronchoalveolar lavage (BAL) fluid in normal subjects and by ELISA in normal, “at risk,” and ARDS subjects. The effect of VEGF165and VEGF165b on both human primary endothelial cells and alveolar epithelial cell proliferation was assessed by [3H]thymidine uptake. We found that VEGF165b was widely expressed in normal healthy lung tissue but is reduced in ARDS lung. VEGF121b and VEGF165b were present in whole lung, BAL, and ATII lysate. The proliferative effect of VEGF165on both human primary endothelial cells and human alveolar epithelial cells was significantly inhibited by VEGF165b ( P < 0.01). These data demonstrate that the novel VEGFxxxb family members are expressed in normal lung and are reduced in ARDS. A specific functional effect on primary human endothelial and alveolar epithelial cells has also been shown. These data suggest that the VEGFxxxb family may have a role in repair after lung injury.
Molecular Cytogenetics of the California Condor: Evolutionary and Conservation Implications
Authors: Modi W.S. , Romanov M. , Green E.D. , Ryder O.
Published: March 2010

Evolutionary cytogenetic comparisons involved 5 species of birds (California condor, chicken, zebra finch, collared flycatcher and black stork) belonging to divergent taxonomic orders. Seventy-four clones from a condor BAC library containing 80 genes were mapped to condor chromosomes using FISH, and 15 clones containing 16 genes were mapped to the stork Z chromosome. Maps for chicken and finch were derived from genome sequence databases, and that for flycatcher from the published literature. Gene content and gene order were highly conserved when individual condor, chicken, and zebra finch autosomes were compared, confirming that these species largely retain karyotypes close to the ancestral condition for neognathous birds. However, several differences were noted: zebra finch chromosomes 1 and 1A are homologous to condor and chicken chromosomes 1, the CHUNK1 gene appears to have transposed on condor chromosome 1, condor chromosomes 4 and 9 and zebra finch chromosomes 4 and 4A are homologous to chicken chromosome arms 4q and 4p, and novel inversions on chromosomes 4, 12 and 13 were found. Condor and stork Z chromosome gene orders are collinear and differentiated by a series of inversions/transpositions when compared to chicken, zebra finch, or flycatcher; phylogenetic analyses suggest independent rearrangement along the chicken, finch, and flycatcher lineages.
Comparative Cytogenetic Analysis of the Genus Symphysodon (Discus Fishes, Cichlidae): Chromosomal Characteristics of Retrotransposons and Minor Ribosomal DNA
Authors: Gross M.C. , Schneider C.H. , Valente G.T. , Porto J.I.R. , Martins C. , Feldberg E.
Published: March 2010

As part of a genetic screening program for wild Discus fishes, we analyzed karyotypes and cytogenetic characteristics of Symphysodon aequifasciatus, S. discus and S. haraldi using C-banding and fluorescent in situ hybridization (FISH) with the Rex3 retrotransposon and 5S rDNA probes in mitotic and meiotic chromosomes. In the 3 species, diploid chromosome number was 2n = 60 and karyotypes contained predominantly meta-submetacentric chromosomes. C-banding showed blocks of constitutive heterochromatin mainly in the pericentromeric region. Physical mapping of repetitive 5S rDNA sequences and Rex3 retrotransposons in mitotic and meiotic chromosomes showed partial colocalization of constitutive heterochromatin and repetitive elements. Correlations among the accumulation of repetitive elements, heterochromatinization and chromosome rearrangements have been hypothesized to explain the karyotype differentiation in the Symphysodon genus. The role of repetitive elements in adaptation to highly diverse habitats, as well as in the generation of the phenotypic and genetic variability found in wild Discus populations, needs to be further investigated.
‘Pure’ Partial Trisomy 4q26→q35.2 Resulting from a Familial Unbalanced Translocation t(4;10)(q26;q26.3)
Authors: Zhang Y.-L. , Dai Y. , Tu Z.-G. , Li Q.-Y.
Published: March 2010

A 3-year-old girl with an inherited translocation of 4q onto the long arm of chromosome 10 is reported as a case of ‘pure’ partial trisomy 4q. The main clinical features of the patient included moderate mental retardation (IQ = 40), growth retardation, language handicap, right hand preaxial hexadactyly, and abnormal electroencephalogram. Conventional cytogenetic analysis showed partial trisomy 4q25→qter was present in the patient, both patient’s father and grandmother were apparently balanced translocation t(4;10) (q25;q26) carriers, which suggests that the partial trisomy 4q25→qter in the patient results from unbalanced segregation of the father’s translocation. The extension of the trisomic 4q region was redefined by array comparative genomic hybridization (array-CGH), the breakpoint on chromosome 4 was located at 4q26 (between 115,596,658 bp and 118,785,802 bp from the telomere of 4p), and an ∼0.54-Mb microdeletion del(10)(q26.3) (between 134,750,859 bp and 135,286,223 bp from the telomere of 10p) was identified. FISH and RT-qPCR confirmed that del(10)(q26.3) was also present in both father and grandmother, which suggests that their translocations are actually unbalanced and the patient’s abnormal phenotypes may only ascribe to partial trisomy 4q26→q35.2.
Molecular Cytogenetic Analysis of Cervical Squamous Cell Carcinoma Cells Demonstrates Discordant Levels of Numerical and Structural Chromosomal Instability and Identifies ‘Selected’ Chromosome Rearrangements
Authors: Foster N. , Carter S. , Ng G. , Pett M. , Roberts I. , Coleman N.
Published: March 2010

The processes underlying the karyotype complexity and heterogeneity characteristic of cervical squamous cell carcinoma (SCC) cells are not well understood, nor is it known which chromosome abnormalities provide a selective advantage. We used molecular cytogenetics to quantify for the first time the prevalence of all chromosomal abnormalities detectable in 8 cervical SCC cell lines. Of 225 rearrangements identified, 118 occurred frequently (≧70% metaphases) in one or more lines, indicating selection. Most of these selected rearrangements (107; 48% of the total) were included in published lists of abnormalities detected in independent cell stocks (although their significance was not previously recognised), indicating that they arose early in the establishment of the lines and were therefore most likely to have been present in the original tumours. The 8 cell lines showed 4.7- and 11.0-fold variation in levels of numerical and structural chromosomal instability (N-CIN and S-CIN) respectively, as determined by quantifying non-clonal abnormalities. We observed discordance between N-CIN and S-CIN (p = 0.148), with modal chromosome number showing a strong association with N-CIN (p = 0.007) but not with S-CIN (p = 0.602). These data imply that different mechanisms underlie N-CIN and S-CIN in cervical SCC. Despite ongoing S-CIN, newly arisen in vitro rearrangements were infrequently selected, supporting the view that selection is an important determinant of somatic evolution in malignancy. There was a positive association between numbers of non-clonal and clonal rearrangements (p = 0.002 for non-clonal vs. selected rearrangements), suggesting that factors affecting S-CIN determine the total numbers of rearrangements present in established cervical SCC cells.
Activation of AMP-Activated Protein Kinase by 5-Aminoimidazole-4-Carboxamide-1-β-
d
-Ribofuranoside in the Muscle Microcirculation Increases Nitric Oxide Synthesis and Microvascular Perfusion
Authors: Bradley Eloise A. , Eringa Etto C. , Stehouwer Coen D.A. , Korstjens Iolente , van Nieuw Amerongen Geerten P. , Musters Rene , Sipkema Pieter , Clark Michael G. , Rattigan Stephen
Published: March 2010

Objective—

To investigate the effects of activation of the AMP-activated protein kinase (AMPK) on muscle perfusion and to elucidate the mechanisms involved.

Methods and Results—

In a combined approach, we studied the vasoactive actions of AMPK activator by 5-aminoimidazole-4-carboxamide-1-β-
d
-ribofuranoside (AICAR) on rat cremaster muscle resistance arteries (≈100 μm) ex vivo and on microvascular perfusion in the rat hindlimb in vivo. In isolated resistance arteries, AICAR increased Thr172 phosphorylation of AMPK in arteriolar endothelium, which was predominantly located in microvascular endothelium. AICAR induced vasodilation (19±4% at 2 mmol/L,
P
<0.01), which was abolished by endothelium removal, inhibition of NO synthase (with
N
-nitro-
l
-arginine), or AMPK (with compound C). Smooth muscle sensitivity to NO, determined by studying the effects of the NO donor
S
-nitroso-
N
-acetylpenicillamine (SNAP), was not affected by AICAR except at the highest dose. AICAR increased endothelial nitric oxide synthase activity, as indicated by Ser1177 phosphorylation. In vivo, infusion of AICAR markedly increased muscle microvascular blood volume (≈60%,
P
<0.05), as was evidenced by contrast-enhanced ultrasound, without effects on blood pressure, femoral blood flow, or hind leg glucose uptake.

Conclusion—

Activation of AMPK by AICAR activates endothelial nitric oxide synthase in arteriolar endothelium by increasing its Ser1177 phosphorylation, which leads to vasodilation of resistance arteries and recruitment of microvascular perfusion in muscle.
Matrix-Specific Protein Kinase A Signaling Regulates p21-Activated Kinase Activation by Flow in Endothelial Cells
Authors: Funk Steven Daniel , Yurdagul Arif , Green Jonette M. , Jhaveri Krishna A. , Schwartz Martin Alexander , Orr A. Wayne
Published: March 2010

Rationale
:

Atherosclerosis is initiated by blood flow patterns that activate inflammatory pathways in endothelial cells. Activation of inflammatory signaling by fluid shear stress is highly dependent on the composition of the subendothelial extracellular matrix. The basement membrane proteins laminin and collagen found in normal vessels suppress flow-induced p21 activated kinase (PAK) and nuclear factor (NF)-κB activation. By contrast, the provisional matrix proteins fibronectin and fibrinogen found in wounded or inflamed vessels support flow-induced PAK and NF-κB activation. PAK mediates both flow-induced permeability and matrix-specific activation of NF-κB.

Objective
:

To elucidate the mechanisms regulating matrix-specific PAK activation.

Methods and Results
:

We now show that matrix composition does not affect the upstream pathway by which flow activates PAK (integrin activation, Rac). Instead, basement membrane proteins enhance flow-induced protein kinase (PK)A activation, which suppresses PAK. Inhibiting PKA restored flow-induced PAK and NF-κB activation in cells on basement membrane proteins, whereas stimulating PKA inhibited flow-induced activation of inflammatory signaling in cells on fibronectin. PKA suppressed inflammatory signaling through PAK inhibition. Activating PKA by injection of the prostacyclin analog iloprost reduced PAK activation and inflammatory gene expression at sites of disturbed flow in vivo, whereas inhibiting PKA by PKA inhibitor (PKI) injection enhanced PAK activation and inflammatory gene expression. Inhibiting PAK prevented the enhancement of inflammatory gene expression by PKI.

Conclusions
:

Basement membrane proteins inhibit inflammatory signaling in endothelial cells via PKA-dependent inhibition of PAK.
Histone Deacetylase 7 Controls Endothelial Cell Growth Through Modulation of β-Catenin
Authors: Margariti Andriana , Zampetaki Anna , Xiao Qingzhong , Zhou Boda , Karamariti Eirini , Martin Daniel , Yin Xiaoke , Mayr Manuel , Li Hongling , Zhang Zhongyi , De Falco Elena , Hu Yanhua , Cockerill Gillian , Xu Qingbo , Zeng Lingfang
Published: March 2010

Rationale
:

Histone deacetylase (HDAC)7 is expressed in the early stages of embryonic development and may play a role in endothelial function.

Objective
:

This study aimed to investigate the role of HDAC7 in endothelial cell (EC) proliferation and growth and the underlying mechanism.

Methods and Results
:

Overexpression of HDAC7 by adenoviral gene transfer suppressed human umbilical vein endothelial cell (HUVEC) proliferation by preventing nuclear translocation of β-catenin and downregulation of T-cell factor-1/Id2 (inhibitor of DNA binding 2) and cyclin D1, leading to G
1
phase elongation. Further assays with the TOPFLASH reporter and quantitative RT-PCR for other β-catenin target genes such as Axin2 confirmed that overexpression of HDAC7 decreased β-catenin activity. Knockdown of HDAC7 by lentiviral short hairpin RNA transfer induced β-catenin nuclear translocation but downregulated cyclin D1, cyclin E1 and E2F2, causing HUVEC hypertrophy. Immunoprecipitation assay and mass spectrometry analysis revealed that HDAC7 directly binds to β-catenin and forms a complex with 14-3-3 ε, ζ, and η proteins. Vascular endothelial growth factor treatment induced HDAC7 degradation via PLCγ-IP3K (phospholipase Cγ–inositol-1,4,5-trisphosphate kinase) signal pathway and partially rescued HDAC7-mediated suppression of proliferation. Moreover, vascular endothelial growth factor stimulation suppressed the binding of HDAC7 with β-catenin, disrupting the complex and releasing β-catenin to translocate into the nucleus.

Conclusions
:

These findings demonstrate that HDAC7 interacts with β-catenin keeping ECs in a low proliferation stage and provides a novel insight into the mechanism of HDAC7-mediated signal pathways leading to endothelial growth.
Quality of Care and Outcomes in Patients With Diabetes Hospitalized With Ischemic Stroke
Authors: Reeves Mathew J. , Vaidya Robert S. , Fonarow Gregg C. , Liang Li , Smith Eric E. , Matulonis Robert , Olson DaiWai M. , Schwamm Lee H.
Published: March 2010

Background and Purpose—

Diabetes is a common comorbid disease in stroke patients and has a strong influence on stroke-related outcomes, including stroke recurrence. We sought to examine the quality of care and in-hospital outcomes in patients with diabetes in the Get With the Guidelines–Stroke (GWTG-Stroke) program.

Methods—

Data were obtained from 415 926 ischemic stroke patients from 1070 United States hospitals that participated in GWTG-Stroke between 2003 and 2008. We analyzed the relationships between diabetes and quality of care, in-hospital mortality, and discharge home using multivariable logistic regression.

Results—

There were 130 817 (31%) ischemic stroke patients with diabetes. Quality of care received by patients with and without diabetes was similar except for intravenous recombinant tissue plasminogen activator (rt-PA) and cholesterol treatment. Fifty-four percent of patients with diabetes who arrived within 2 hours of onset received rt-PA compared to 60.8% of patients without diabetes (adjusted odds ratio [aOR], 0.83; 95% CI, 0.79–0.88). Almost 80% of patients with diabetes were discharged on cholesterol treatment compared to 71% of patients without diabetes (aOR, 1.40; 95% CI, 1.37–1.44). Diabetes patients were less likely to be discharged home (aOR, 0.80; 95% CI, 0.78–0.81) and had a higher risk of in-hospital death (aOR, 1.12; 95% CI, 1.08–1.15).

Conclusions—

Quality of care among patients with and without diabetes was similar except for rt-PA and cholesterol treatment. Diabetes was associated with worse stroke-related outcomes. Greater quality-improvement efforts to increase the use of rt-PA and other secondary prevention treatments in patients with diabetes are warranted.
Bimodality in a Monostable Climate–Ecosystem: The Role of Climate Variability and Soil Moisture Memory*
Authors: Liu Zhengyu
Published: March 2010

The probabilistic modal response of vegetation to stochastic precipitation variability is studied in a conceptual climate–ecosystem model. It is found that vegetation can exhibit bimodality in a monostable climate–ecosystem under strong rainfall variability and with soil moisture memory comparable with that of the vegetation. The bimodality of vegetation is generated by a convolution of a nonlinear vegetation response and a colored stochastic noise. The nonlinear vegetation response is such that vegetation becomes insensitive to precipitation variability near either end state (green or desert), providing the potential for two preferred modes. The long memory of soil moisture allows the vegetation to respond to a slow stochastic forcing such that the vegetation tends to grow toward its equilibrium states. The implication of the noise-induced bimodality to abrupt changes in the climate–ecosystem is also discussed.
Structures and Seasonal Variations of Surface Winds Blowing through the Tsushima Strait
Authors: Shimada Teruhisa
Published: March 2010

Surface winds blowing through the Tsushima Strait are statistically investigated using satellite wind measurements and atmospheric reanalysis data. This study first presents structures and seasonal variations of the northeasterly and southwesterly along-strait winds by imposing newly proposed conditions for defining them. Although the speeds of the northeasterly along-strait winds are generally high within the entire strait, the maximum wind speeds are located downwind of the two channels. The southwesterly along-strait winds start to accelerate at the west exit within the strait. Weak-wind regions are formed in the lee of Tsushima Island in both cases. The occurrence frequencies of the northeasterly and southwesterly along-strait winds are high (low) in the warm (cool) season. The northeasterly along-strait winds are more often observed than the southwesterly along-strait winds. The frequency of the northeasterly along-strait wind is extraordinarily high in September, but the averaged wind speed is comparable to those in the other months. Most of the southwesterly along-strait wind cases fall within low-Froude-number regimes, suggesting the significant effects of Tsushima Island on the wind in the strait. Synoptic situations favorable for the along-strait winds are investigated. Correlations between the along-strait wind component and sea level pressure (SLP) indicate that the along-strait winds are induced by SLP perturbations primarily over the Japan Sea and secondarily on the south of the strait. In addition, cluster analysis of the SLP fields shows four representative SLP fields favorable for the along-strait winds and their monthly occurrence frequencies.
Persistent Multiple Jets and PV Staircase
Authors: Yoo Changhyun , Lee Sukyoung
Published: March 2010

The persistence of multiple jets is investigated with a quasigeostrophic, two-layer, β-plane channel model. Linearly unstable normal modes are found to be capable of qualitatively describing the eddy fluxes of the nonlinear model. For a persistent double jet (PDJ) state, the most unstable normal mode has its largest amplitude located between the two jets, with a downshear tilt that acts to keep the jets separated. The opposite tilt occurs for a double jet state that is intermittent. An analysis of these normal modes, which utilized the concept of counterpropagating Rossby waves (CRWs), suggests that the downshear tilt in the interjet region hinges on the presence of critical latitudes only in the lower layer. This conclusion in turn suggests that the initial generation of the persistent jets requires L/Cgy < r−1, where L is the distance between the wave source (jet) and sink (interjet), Cgy is the meridional group velocity, and r is the linear damping rate. Similar CRW analysis for a conventional normal mode, which has its largest amplitude at the jet centers, suggests that the downshear tilt adjacent to the jet maxima is associated with the presence of critical latitudes only in the upper layer. The PDJ is found to be accompanied by potential vorticity (PV) staircases in the upper layer, characterized by a strong PV gradient at the jet centers and a broad region of homogenized PV between the jets. This PV mixing is realized through baroclinic waves that propagate slowly westward in the interjet region. Nonlinear evolution of the most unstable normal mode of the PDJ shows that northward heat flux by these waves is crucial for broadening the interjet PV mixing zone necessary for producing the PV staircase.
Upstream Internal Jumps in Stratified Sill Flow: Observations of Formation, Evolution, and Release
Authors: Cummins Patrick F. , Armi Laurence
Published: March 2010

The time-dependent response of upstream undular bores and internal hydraulic jumps from initial formation to eventual release is documented. Two events, characterized by qualitatively different responses, are discussed. In the first case, an undular bore develops upstream of the sill crest. This disturbance remains upstream through the ebb tidal flow but is transformed to a hydraulic jump as its amplitude increases. Toward the end of ebb tide, it is released and subsequently disperses into a group of solitary-like waves. During the second event, an upstream jump also develops at an early stage of the tide. However, it is subsequently swept downstream by the tidal flow such that the upstream region then appears featureless. Approaching slack tide, as an exchange flow becomes established, a large bore or gravity current is emitted. The different responses seen in these two events are interpreted in terms of the Froude number associated with the near-surface stratification.
Atmospheric Scale Interaction on Wintertime Intermountain West Low-Level Inversions
Authors: Gillies Robert R. , Wang Shih-Yu , Booth Marty R.
Published: March 2010

Persistent winter inversions result in poor air quality in the Intermountain West of the United States. Although the onset of an inversion is relatively easy to predict, the duration and the subsequent breakup of a persistent inversion event remains a forecasting challenge. For this reason and for this region, historic soundings were analyzed for Salt Lake City, Utah, with reanalysis and station data to investigate how persistent inversion events are modulated by synoptic and intraseasonal variabilities. The results point to a close linkage between persistent inversions and the dominant intraseasonal (30 day) mode that characterizes the winter circulation regime over the Pacific Northwest. Meteorological variables and pollution (e.g., particulate matter of ≤2.5-μm diameter, PM2.5) revealed coherent variations with this intraseasonal mode. The intraseasonal mode also modulates the characteristics of the synoptic (6 day) variability and further influences the duration of persistent inversions in the Intermountain West. The interaction between modes suggests that a complete forecast of persistent inversions is more involved and technically beyond numerical weather prediction models intended for the medium range (∼10 day). Therefore, to predict persistent inversions, the results point to the adoption of standard medium-range forecasts with a longer-term climate diagnostic approach.
Internet Service Provision in the U.S. Counties: Is Spatial Pattern a Function of Demand?
Authors: Khatiwada Lila K. , Pigg Kenneth E.
Published: March 2010

The Internet has become an important part of the daily lives of millions of Americans. Despite its importance, there is little empirical knowledge about the spatial pattern of Internet growth. Using the number of ISPs (Internet service providers) as an indicator of Internet diffusion and adoption, the authors attempt to understand the spatial pattern of Internet adoption and the factors responsible. Specifically, they seek to answer three research questions: Do U.S. counties exhibit differences in Internet adoption? If so, what is the pattern of adoption? and How do county-level socioeconomic and geographical factors affect the adoption of Internet services? For the spatial analysis, polygon pattern analysis is used to see the pattern of Internet adoption. Three spatial error models (for all counties, metro counties, and nonmetro counties) are used to investigate the relationship between various county-level demand indicators and Internet service status. The result shows that market demand is the driving force as counties that are more urban, have more educated people, more business establishments, and higher housing value also have higher ISP presence. This finding implies that the remote and rural areas will continue to suffer from poor Internet access.
The Nuances and Complexities of Teaching Mathematics for Cultural Relevance and Social Justice
Authors: Leonard Jacqueline , Brooks Wanda , Barnes-Johnson Joy , Berry Robert Q.
Published: March 2010

Mathematics is not a race-neutral subject. Access and opportunity in mathematics for students of color in the United States continue to be limited. While a great deal of attention has been given to increasing the number of underrepresented minority students in the mathematics pipeline, there is little consideration of who they are as learners or the context in which their mathematics learning takes place. We argue that culturally relevant instruction coupled with teaching for social justice can motivate marginalized students to learn mathematics. Throughout this conceptual article, we (a) explore the theoretical frameworks underlying culturally relevant pedagogy (CRP) and social justice pedagogy (SJP), (b) present illustrative cases of mathematics teaching that reveal the possibilities and challenges associated with these pedagogical approaches, and (c) offer to the field of teacher education recommendations related to the successful use of CRP and SJP within today's classrooms.
Automatic Detection of the Layout of Color Yarns for Yarn-dyed Fabric via a FCM Algorithm
Authors: Ruru Pan  , Weidong Gao  , Jihong Liu  , Hongbo Wang
Published: March 2010

In the process of analyzing the yarn-dyed fabric, two kinds of color information about color yarns should be detected: (1) the number of yarn colors; (2) the layout of the color yarns. The traditional detection methods are time-consuming and labor-intensive. An automatic method based on image analysis is proposed in this study. The image of yarn-dyed fabric captured with a flat scanner is analyzed by a fuzzy C-means clustering (FCM) algorithm. By the analysis of the image of the yarn-dyed fabric based with the FCM algorithm, we can conclude that the number of yarn colors can be obtained with cluster validity analysis, and the layout of color yarns can be inspected automatically with the help of Hough transform. Experiments on two actual fabrics show that the approach proposed in this study is effective for detecting the number of yarn colors and the layout of color yarns in the yarn-dyed fabric.
Simulation of the Effect of Air Gaps between the Skin and a Wet Fabric on Resulting Cooling Flow
Authors: Hes Lubos , de Araujo Mario
Published: March 2010

As the moisture content of a fabric increases, the relative water vapor permeability (the relative heat flow responsible for the cooling of the body) also increases and the fabric temperature drops due to the evaporation of the water from the surface of the fabric. In this work on the experimental study of water vapor permeability of wet fabrics, the effect of air layers between the skin of the wearer and the fabric on the total relative cooling heat flow (cooling effect) experienced by the skin of the garment wearer is investigated. It was found out that when layers of 2- and 4-mm thickness were introduced between the skin and the fabric, the relative water vapor permeability or relative cooling heat flow was smaller than when the fabric was in direct contact with the skin, and in this case it did not depend significantly on the fabric moisture content.