bluuebunny/crossref_metadata_2025 huggingface dataset:
Confocal laser‐scanning capillaroscopy: a novel approach to the analysis of skin capillaries in vivo
Authors: Hegyi J. , Hegyi V. , Messer G. , Arenberger P. , Ruzicka T. , Berking C.
Published: September 2009

Background: New techniques for diagnostics and therapy in dermatology are becoming increasingly non‐invasive, among which confocal laser‐scanning microscopy (CLSM) is the most prevalent. It allows visualization of cellular structures of the skin up to a depth of 300 μm in vivo. Until now, most studies have been conducted on pathologically altered skin, mostly oncologic lesions. We now present a detailed analysis of capillaries located in the upper dermal papillae.

Methods: Multiple measurements were performed on the dorsal and ventral surface of the right forearm of 30 healthy volunteers (22–88 years) under standard conditions (room temperature, body position, time of day). Images were obtained with the Vivascope 1500 (Lucid) under standard settings and analyzed using the freeware ImageJ with a customwritten macro plugin. The following parameters of the capillaries in vivo were measured: area, perimeter, circularity and maximum diameter.

Results: Statistical analysis showed that all four parameters were constant within a narrow range, regardless of the body site, sex and age. In this physiological study, we can clearly demonstrate that by confocal laser‐scanning capillaroscopy (CLSC), it is possible to visualize and measure skin capillaries at the extremities in a reproducible manner.

Conclusion: This new approach offers a considerable advantage compared with nailfold capillaroscopy, which can only be performed at the proximal nail segment, and over histological analysis, which can be hampered by fixation artifacts resulting in altered size and shape of the vessels to be analyzed. CLSC could allow for precise analysis of in vivo skin vasculature in systemic and proliferative diseases of the skin.
Wavelength effects on contrast observed with reflectance in vivo confocal laser scanning microscopy
Authors: Luedtke Michael A. , Papazoglou Elisabeth , Neidrauer Michael , Kollias Nikiforos
Published: September 2009

Background/purpose: The ability to optically section live biological tissue in vivo with laser light is made possible by confocal laser scanning microscopy (CLSM). In this work, the effects of changing the wavelength of incident light used for CLSM imaging of human skin are reported and analyzed.

Methods: Optical phantoms and the skin of eight human volunteers were imaged using CLSM systems having three different incident light wavelengths (405, 785, and 830 nm).

Results: Qualitative and quantitative differences were observed between images obtained at each wavelength, despite the proximity of the two near infrared 785 and 830 nm wavelengths. Furthermore, the penetration depth achieved with the 405 nm CLSM permitted imaging into the papillary dermis.

Conclusion: The laser wavelength used in CLSM reflectance imaging is important to properly understand and resolve different biological structures within human skin.
Oxidant/antioxidant status in recurrent aphthous stomatitis
Authors: Arikan S , Durusoy C , Akalin N , Haberal A , Seckin D
Published: September 2009

Objective:  Recurrent aphthous stomatitis (RAS) is a common oral mucosal disorder characterized by recurrent, painful oral aphthae, and oxidative stress presumably contributes to its pathogenesis. The study was performed to evaluate the involvement of oxidant toxicity in this disorder.

Methods:  Patients with RAS (n = 26) and age‐ and sex‐matched healthy control subjects (n = 20) were included in this study. Following an overnight fast, blood specimens were obtained. Plasma malondialdehyde concentrations and erythrocytes glutathione peroxidase activities were determined. Also, plasma vitamin E and selenium levels were detected. Mann–Whitney U‐test was performed for statistical evaluation.

Results:  Oxidative stress was confirmed by the significant elevation in plasma malondialdehyde levels and by the significant decrease in glutathione peroxidase activities, vitamin E and selenium levels (P < 0.001).

Conclusions:  Our results indicated that lipid peroxidation and the inadequacy of the defense system seem to play a crucial role in the pathogenesis of recurrent aphthous stomatitis.
Invasive grass litter facilitates native shrubs through abiotic effects
Authors: Wolkovich Elizabeth M. , Bolger Douglas T. , Cottingham Kathryn L.
Published: September 2009

Questions:Plant invasions are considered one of the top threats to the biodiversity of native taxa, but clearly documenting the causal links between invasions and the decline of native species remains a major challenge of invasion biology. Most studies have focused on impacts of invaders' living biomass, rather than on mechanisms mediated by litter. However, invasive plant litter, which is often of a very different type and quantity than a system's native plant litter, can have multiple important effects on ecosystem processes – such as nitrogen cycling and soil microclimate – that may influence native plants.

Location:We studied effects of litter of invasive grass species that are widespread throughout western North America on native shrubs in southern California's semi‐arid habitat of coastal sage scrub.

Methods:We combined a 3‐year field manipulation of non‐native litter with structural equation modeling to understand interacting effects on non‐native grasses, native shrubs, soil nitrogen (available and total), and soil moisture.

Results:Litter addition facilitated non‐native grass growth, revealing a positive feedback likely to enhance invasion success. Contrary to a major paradigm of invasion biology – that competition with invasive plant species causes declines of native plants – we found that litter also facilitated growth of the native dominant shrub, a result supported by observational trends. Structural equation models indicated that enhanced soil moisture mediated the positive effects of litter on shrub growth.

Conclusions:We demonstrate that invasive plants, via their litter, can facilitate dominant native plants by altering soil moisture. Our results highlight that understanding the impacts and mechanisms of plant invasions may be enhanced by considering the role of invasive plant litter on native plants and ecosystem properties.
Increasing deterministic control of primary succession on Mount St. Helens, Washington
Authors: Del Moral Roger
Published: September 2009

Question: Does the relative importance of stochastic and deterministic factors change during primary succession?

Location: Small depressions (potholes) located on Mount St. Helens, Washington (46°13′51″N, 122°09′10″W, 1290 m).

Methods: Pothole vegetation was described in 1993, 1997 and from 2001 to 2008. Explanatory variables included location and elevation (spatial factors), soil factors and Lupinus lepidus cover from prior years (a fertility surrogate). RDA assessed species‐variable relationships. DCA calculated β diversity and within‐year heterogeneity. Flexible sorting classified the vegetation. Species composition, richness, cover, H′ and evenness were also calculated.

Results: Vegetation cover increased through 2001, and then fluctuated due to changes in L. lepidus cover. Richness peaked in 2005, after which pioneer species began to decline as persistent evergreen species increased. The six CTs recognized in 2008 were more scattered than were the six different CTs from 2001. DCA demonstrated that woody and rhizomatous species increased as pothole vegetation became less variable. RDA revealed weak spatial relationships in 1993, 1997 and 2001; thereafter, environmental and biological factors became important. The species‐explanatory data relationship increased during this study from 10.2% to 36.0%, leaving 64.0% of the variation unexplained.

Conclusions: This is the first temporal study to demonstrate that deterministic control of vegetation development increases during succession. Pothole vegetation has converged somewhat due to deterministic factors, but the initial effects of chance, local disturbances and history remain large and may prevent strong convergence.
Identification of a potent immunostimulatory oligodeoxynucleotide from Streptococcus thermophilus lacZ
Authors: SHIMOSATO Takeshi , TOHNO Masanori , SATO Takashi , NISHIMURA Junko , KAWAI Yasushi , SAITO Tadao , KITAZAWA Haruki
Published: September 2009

Immunostimulatory sequences of oligodeoxynucleotides (ODNs), such as CpG ODNs, are potent stimulators of innate immunity. Here, we identified a strong immunostimulatory CpG ODN, which we named MsST, from the lac Z gene of Streptococcus (S.) thermophilus ATCC19258, and we evaluated its immune functions. In in vitro studies, MsST had a similar ability as the murine prototype CpG ODN 1555 to induce inflammatory cytokine production and cell proliferation. In mouse splenocytes, MsST increased the number of CD80+CD11c+and CD86+CD11c+ dendritic cells and CD4+CD25+ regulatory T cells. We also analyzed the effects of MsST on the expression of regulatory cytokines by real‐time quantitative PCR. MsST was more potent at inducing interleukin‐10 expression than the ODN control 1612, indicating that MsST can augment the regulatory T cell response via Toll‐like receptor 9, which plays an important role in suppressing T helper type 2 responses. These results suggest that S. thermophilus, whose genes include a strong Immunostimulatory sequence‐ODN, is a good candidate for a starter culture to develop new physiologically functional foods and feeds.
Muscle type‐specific effect of myostatin deficiency on myogenic regulatory factor expression in adult double‐muscled Japanese Shorthorn cattle
Authors: MUROYA Susumu , WATANABE Kouichi , HAYASHI Shinichiro , MIYAKE Masato , KONASHI Shigeru , SATO Youichi , TAKAHASHI Manabu , KAWAHATA Shigeki , YOSHIKAWA Yoshisato , ASO Hisashi , CHIKUNI Koichi , YAMAGUCHI Takahiro
Published: September 2009

To clarify muscle type‐specific effect of myostatin on myogenic regulatory factors (MRFs), we examined mRNA expression of MRFs in five skeletal muscles of normal (NM) and myostatin‐deficient double‐muscled (DM) adult Japanese Shorthorn cattle by quantitative reverse‐transcribed PCR. Among the four MRFs, namely, Myf5, MyoD, myogenin, and MRF4, MyoD expression was different among the muscles of the DM cattle (P < 0.01) but not of the NM cattle. Meanwhile, MyoD expression was significantly elevated only in masseter (MS) muscle in the DM cattle due to the myostatin deficiency (P < 0.05). Myf5 and MRF4 expression in semitendinosus (ST) was higher in the DM than in the NM cattle (P < 0.05). According to analysis of myosin heavy chain (MyHC) isoform expression, more MyHC‐2x and ‐2a and less ‐slow isoforms were expressed in the longissimus and ST muscles compared to the MS muscle in both cattle (P < 0.05), but no significant difference in MyHC expression was observed between the NM and DM cattle. Taken together, myostatin has influences on Myf5 and MRF4 expression in faster‐type muscles and on MyoD expression in slower‐type muscles, suggesting a possible muscle type‐specific effect of myostatin in skeletal muscle growth and maintenance.
Is One Dimension Enough?: A Response to Simonton's Varieties of (Scientific) Creativity (2009)
Authors: Kaufman James C. , Baer John
Published: September 2009

We admire Simonton's valiant attempt to bring all of creativity under a single dimension. We offer a view that is sometimes complementary and sometimes distinct from Simonton's model: Our own multidimensional amusement park theoretical model, which tries to integrate domain-specific and domain-general points of view. We eagerly await future research on Simonton's model and are curious of how his hard–soft dimension can be included into the creativity pantheon.
Simplifying Theories of Creativity and Revisiting the Criterion Problem: A Comment on Simonton's (2009) Hierarchical Model of Domain-Specific Disposition, Development, and Achievement
Authors: Runco Mark A.
Published: September 2009

Simonton's (2009, this issue) hierarchical model represents a useful contribution to studies of creativity and eminence. Simonton breaks all kinds of new ground by extrapolating the hierarchy to the arts and humanities, interpolating it within disciplines, and relating it to family background and disposition. This commentary poses a few questions about the hierarchical model and proposes an alternative. I also introduce a candidate for a simple theory of creativity that focuses on a universally shared capacity. This simple theory complements Simonton's hierarchical view, though his applies best to actual performance and the simple theory of creativity applies to creative potential.
Varieties of Perspectives on Creativity: Reply to Commentators
Authors: Simonton Dean Keith
Published: September 2009

In this reply, I concentrate on two broad issues raised by the four commentaries in this issue: the hierarchical model of domains and individual differences in creativity. In the first case, I cite additional research to address the contrast between “hard” and “soft” domains and the application of this contrast to children, adolescents, and noneminent adults. In the second case, I introduce two recent studies to confirm the model's predictions regarding personal creative achievement. I hope that the original article, the commentaries, and this reply will inspire future inquiries into creativity in all its disciplinary varieties.
Empire, Patriotism and the Working‐Class Electorate: The 1900 General Election in the Battersea Constituency
Authors: SHARPE IAIN
Published: September 2009

The extent to which the Unionist victory in the ‘khaki’ general election of 1900 was the result of patriotic sentiment arising from the South African war has long been a source of controversy among historians. Battersea has been cited as an area that was largely unaffected by patriotic and imperial fervour during this period. This article examines the general election campaign in the Battersea constituency. The sitting MP, John Burns, was re‐elected despite his opposition to the war, but the Conservatives achieved their highest percentage vote of that at any parliamentary election between 1885 and 1918. While the war was not the only issue raised during the campaign, it was the most prominent and clearly benefited the imperialist and pro‐war Conservative candidate. In order to retain his seat Burns had to fight a far more dynamic local campaign than his opponent, and even then he won only narrowly. Although imperial sentiment was not quite enough to oust Burns from this otherwise safe seat, it was the main reason for the strong Conservative performance.
Politicians, Parishes and Police: The Failure of the 1812 Night Watch Bill
Authors: PALEY RUTH , REYNOLDS ELAINE A.
Published: September 2009

The public outcry heard in the wake of the Ratcliffe Highway murders of December 1811 was muted by May 1812 when the 1812 Night Watch Bill died in the house of commons. Responding to the moral panic following the murder of two East End families, the home office gathered considerable information and input from the professional police magistrates and local authorities before proposing the reform of parochial night watch in much of metropolitan London. Nevertheless the bill ran into concerted opposition on grounds of practicality as well as of ideology. A close study of its trajectory through parliament illuminates the role of parliament as a broker for conflicting demands emanating from differing concepts of the public good. The failure of the Night Watch Bill adds significantly to our understanding of the genesis of legislative initiatives, calling into question whether it is possible to distinguish accurately whether particular bills originated from back‐ or front‐bench activity as well as to our knowledge of the relationship between parliamentary activity, ministerial objectives and public opinion.
When Words Fail: William Pitt, Benjamin Franklin and the Imperial Crisis of 1766
Authors: YORK NEIL
Published: September 2009

Passage of an American stamp tax in 1765 produced a sharp political backlash before the year was out. That new tax was part of a larger programme of imperial reform championed by the Grenville ministry. Now out of power, Grenville and his supporters resisted the growing desire in both houses of parliament to end the imperial crisis by repealing the new tax. During debates that began in early 1766 there were those few, most notably William Pitt, who wanted to discuss constitutional ultimates as part of the move toward repeal. Pitt contended that parliament did not have the authority to tax the colonies directly. Grenville disagreed and warned that if parliament accepted any limit to its supremacy the colonists would eventually claim legislative autonomy. When debating the distinction – if indeed any such distinction existed – between taxation and legislation, and between internal and external taxes, Pitt, Grenville and their parliamentary contemporaries raised questions about authority and power that they could not answer. There were no words to describe perfectly the imperial relationship, a relationship that, as Benjamin Franklin hinted in his testimony to the Commons, was always subject to change anyway. Avoiding constitutional questions had not seemed to work; trying to answer them did not work any better, at least in the contentious atmosphere of that moment.
‘J'y Suis, J'y Reste’: The Parliamentary Statue of Oliver Cromwell by Hamo Thornycroft
Authors: UNWIN MELANIE
Published: September 2009

The conservation of the statue of Cromwell by Hamo Thornycroft in 2009 (for full details and images see http://www.parliament.uk/about/visiting/exhibitions/cromwell_conservation.cfm) provided an opportunity to review the history of this most controversial of parliamentary statues both within the context of the proposed statue programme for the new palace of Westminster and the development of British sculpture which the Royal Commission for the Fine Arts hoped to encourage with its commissioning programme. Whilst 2009 marked the 350th anniversary of Cromwell's death it was the tercentenary of his birth in 1899 which brought forward a clutch of statues, including parliament's, reflecting the Victorian reassessment, and indeed repopularisation of Cromwell, as a historical figure.
Comparison of Office, Ambulatory, and Home Blood Pressure Antihypertensive Response to Atenolol and Hydrochlorthiazide
Authors: Beitelshees Amber L. , Gong Yan , Bailey Kent R. , Turner Stephen T. , Chapman Arlene B. , Schwartz Gary L. , Gums John G. , Boerwinkle Eric , Johnson Julie A.
Published: September 2009

J Clin Hypertens (Greenwich). 2010;12:14–21. ©2009 Wiley Periodicals, Inc.

Office, home, and ambulatory blood pressure (BP) demonstrate variable associations with outcomes. The authors sought to compare office BP (OBP), home BP (HBP), and ambulatory BP (ABP) for measuring responses to hydrochlorothiazide (HCTZ), atenolol, and their combination. After completing washout, eligible patients were randomized to atenolol 50 mg or HCTZ 12.5 mg daily. Doses were doubled after 3 weeks and the alternate drug was added after 6 weeks if BP was >120/70 mm Hg (chosen to allow maximum opportunity to assess genetic associations with dual BP therapy in the parent study). OBP (in triplicate), HBP (twice daily for 5 days), and 24‐hour ABP were measured at baseline, after monotherapy, and after combination therapy. BP responses were compared between OBP, HBP, and ABP for each monotherapy and combination therapy. In 418 patients, OBP overestimated BP response compared with HBP, with an average 4.6 mm Hg greater reduction in systolic BP (P<.0001) and 2.1 mm Hg greater reduction in diastolic BP (P<.0001) across all therapies. Results were similar for atenolol and HCTZ monotherapy. ABP response was more highly correlated with HBP response (r=0.58) than with OBP response (r=0.47; P=.04). In the context of a randomized clinical trial, the authors have identified significant differences in HBP, OBP, and ABP methods of measuring BP response to atenolol and HCTZ monotherapy.
Increased Phosphorylation‐Dependent Nuclear Export of Class II Histone Deacetylases in Failing Human Heart
Authors: Calalb Mihail B. , McKinsey Timothy A. , Newkirk Scott , Huynh Khai , Sucharov Carmen C. , Bristow Michael R.
Published: September 2009

In the failing human heart (FHH) the induction of a fetal contractile protein gene program is directly and selectively associated with the dilated cardiomyopathy (DCM) phenotype and involves multiple signaling pathways. In response to cardiac stress signals, class II HDACs are subject to phosphorylation dependent nuclear export, which allows for activation of fetal cardiac genes via the transcription factor MEF2. The current study tests the hypothesis that MEF2 activation produced by class II HDAC de‐repression is present in the FHH. In this study, human left ventricular tissue from nonfailing and failing adult hearts was analyzed for the presence of MEF2, HDACs 4 and 5. CaMK and HDAC kinase activities were measured in tissue homogenates. In nuclear fractions from failing ventricles, HDAC4 and HDAC5 protein was decreased versus nonfailing controls. MEF2 was not reduced in failing nuclear fractions. CaMK and HDAC kinase activities were increased in failing versus nonfailing hearts. PKCμ (PKD1) activity was increased in nuclear fractions from failing human LVs. These data provide support for decreased nuclear compartment class II HDACs in the FHH, associated with increased activities of kinases known to phosphorylate class II HDACs.
The identity and typification of Stylogyne laxiflora (Myrsinaceae)
Authors: Carrijo Tatiana Tavares , De Fátima Freitas Maria , Luna Peixoto Ariane
Published: September 2009

Stylogyne laxiflora Mez is transferred to the genus Ardisia Sw. (Myrsinaceae) as Ardisia spruceana (Mez) Carrijo, M. F. Freitas & A. L. Peixoto due to its bisexual flowers, filaments fused by staminal tube, long style and punctiform stigma. A lectotype for this name is designated. The species is illustrated here for the first time, and a new description is provided. Comments regarding its geographic distribution are presented.
Role of angiotensin II in liver fibrosis‐induced portal hypertension and therapeutic implications
Authors: Lugo‐Baruqui Alejandro , Muñoz‐Valle José Francisco , Arévalo‐Gallegos Sigifredo , Armendáriz‐Borunda Juan
Published: September 2009

Angiotensin II (AT‐II) is a peptide that plays an important role in the renin‐angiotensin‐aldosterone (RAA) system. Traditionally, the RAA system has been related with states of systemic hypertension and hypoperfusion as a counterbalance mechanism. Recently, AT‐II has been studied for its properties in the process of fibrosis in several organs, especially in the liver. AT‐II is capable to stimulate the activated hepatic stellate cells, which increase expression of profibrogenic molecules like tumor growth factor‐β, tissue inhibitor of metalloproteinase‐1 and collagen I, among others. At the same time, AT‐II is implied in the hemodynamic balance of cirrhosis and portal hypertension. Due to its profibrogenic and vasoactive properties, blockade of AT‐II actions constitutes an important therapeutic target to inhibit fibrotic processes and reduction of risk of complications of portal hypertension as well. Some drugs like angiotensin‐converting enzyme inhibitors or the angiotensin II receptor blockers have been studied as alternatives for the treatment of patients with cirrhosis with promising results. Nonetheless, additional research is required in order to consider these drugs as a part of the integral treatment of the patient with cirrhosis and portal hypertension.
South Korea's Missile Defense Policy: Dilemma and Opportunity for a Medium State
Authors: Kim Tae‐Hyung
Published: September 2009

Proliferation of weapons of mass destruction (WMD) delivery systems has made missile defense a key security challenge, but missile defense systems are highly controversial. I closely examine the development of the missile defense system in South Korea. South Korea has steadfastly remained outside the theater missile defense (TMD) structure, but it cooperates on missile defense, in a limited way, with its U.S. ally. South Korea's refusal to participate in TMD even as it quietly acquires air defense systems can be explained by political and diplomatic considerations regarding its neighbors (especially China), military and economic considerations about missile defense, and strategic considerations for the United States‐South Korea alliance. The TMD situation demonstrates South Korea's dilemma and opportunity as a medium power in a particularly harsh security environment. South Korea is walking a fine line to diversify security relations, to maintain the alliance structure with the United States (albeit in a changed form), and to build a self‐reliant military capability.
Differential expression of membrane conductances underlies spontaneous event initiation by rostral midline neurons in the embryonic mouse hindbrain
Authors: Moruzzi Audrey M. , Abedini Nauzley C. , Hansen Matthew A. , Olson Julia E. , Bosma Martha M.
Published: September 2009

Spontaneous activity is expressed in many developing CNS structures and is crucial in correct network development. Previous work using [Ca2+]i imaging showed that in the embryonic mouse hindbrain spontaneous activity is initated by a driver population, the serotonergic neurons of the nascent raphe. Serotonergic neurons derived from former rhombomere 2 drive 90% of all hindbrain events at E11.5. We now demonstrate that the electrical correlate of individual events is a spontaneous depolarization, which originates at the rostral midline and drives events laterally. Midline events have both a rapid spike and a large plateau component, while events in lateral tissue comprise only a smaller amplitude plateau. Lateral cells have a large resting conductance and are highly coupled via neurobiotin‐permeant gap junctions, while midline cells are significantly less gap junction‐coupled and uniquely express a T‐type Ca2+ channel. We propose that the combination of low resting conductance and expression of T‐type Ca2+ current is permissive for midline neurons to acquire the initiator or driver phenotype, while cells without these features cannot drive activity. This demonstrates that expression of specific conductances contributes to the ability to drive spontaneous activity in a developing network.
Coupling an HCN2‐expressing cell to a myocyte creates a two‐cell pacing unit
Authors: Valiunas V. , Kanaporis G. , Valiuniene L. , Gordon C. , Wang H. Z. , Li L. , Robinson R. B. , Rosen M. R. , Cohen I. S. , Brink P. R.
Published: September 2009

We examined whether coupling of a ventricular myocyte to a non‐myocyte cell expressing HCN2 could create a two‐cell syncytium capable of generating sustained pacing. Three non‐myocyte cell types were transfected with the mHCN2 gene and used as sources of mHCN2‐induced currents. They were human mesenchymal stem cells and HEK293 cells, both of which express connexin43 (Cx43), and HeLa cells transfected with Cx43. Cell–cell coupling between heterologous pairs increased with time in co‐culture, and hyperpolarization of the myocyte induced HCN2 currents, indicating current transfer from the mHCN2‐expressing cell to the myocyte via gap junctions. The magnitude of the HCN2 currents recorded in myocytes increased with increasing junctional conductance. Once a critical level of electrical cell–cell coupling between myocytes and mHCN2 transfected cells was exceeded spontaneous action potentials were generated at frequencies of ∼0.6 to 1.7 Hz (1.09 ± 0.05 Hz). Addition of carbenoxolone (200 μm), a gap junction channel blocker, to the media stopped spontaneous activity in heterologous cell pairs. Carbenoxolone washout restored activity. Blockade of HCN2 currents by 100 μm9‐amino‐1,2,3,4‐tetrahydroacridine (THA) stopped spontaneous activity and subsequent washout restored it. Neither THA nor carbenoxolone affected electrically stimulated action potentials in isolated single myocytes. In summary, the inward current evoked in the genetically engineered (HCN2‐expressing) cell was delivered to the cardiac myocyte via gap junctions and generated action potentials such that the cell pair could function as a pacemaker unit. This finding lays the groundwork for understanding cell‐based biological pacemakersin vivoonce an understanding of delivery and target cell geometry is defined.
Finite Deformations and Internal Forces in Elastic-Plastic Crystals: Interpretations From Nonlinear Elasticity and Anharmonic Lattice Statics
Authors: Clayton J. D. , Bammann D. J.
Published: September 2009

Large deformation kinematics and internal forces arising from defects in crystalline solids are addressed by a nonlinear kinematic description and multiscale averaging concepts. An element of crystalline material with spatially uniform properties and containing defects such as dislocation lines and loops is considered. The average deformation gradient for this element is decomposed multiplicatively into terms accounting for effects of dislocation flux, recoverable elastic stretch and rotation, and residual elastic deformation associated with self-equilibrating internal forces induced by defects. Two methods are considered for quantifying average residual elastic deformation: continuum elasticity and discrete lattice statics. Average residual elastic strains and corresponding average residual elastic volume changes are negligible in the context of linear elasticity or harmonic force potentials but are not necessarily inconsequential in the more general case of nonlinear elasticity or anharmonic interactions.
Phase Evolution in Laser Rapid Forming of Compositionally Graded Ti–Ni Alloys
Authors: Lin X. , Yue T. M. , Yang H. O. , Huang W. D.
Published: September 2009

A graded binary titanium-nickel alloy with a compositional gradient, from elemental Ti to Ti–23.2 at. % Ni, has been successfully deposited using laser rapid forming. A metallurgical study of the phase evolution along the compositional gradient showed that a series of phase evolutions α→α+β→α+β+Ti2Ni→β/B2+Ti2Ni have occurred. Phase formation and microstructure evolution along the compositional gradient was analyzed by Scheil–Gulliver and eutectic growth models. In particular, the morphology of the β/B2+Ti2Ni anomalous and coupled eutectic is discussed in detail.
Scale and Boundary Conditions Effects on the Apparent Elastic Moduli of Trabecular Bone Modeled as a Periodic Cellular Solid
Authors: Wang Congyu , Feng Liang , Jasiuk Iwona
Published: September 2009

We study apparent elastic moduli of trabecular bone, which is represented, for simplicity, by a two- or three-dimensional periodic cellular network. The term “apparent” refers to the case when the region used in calculations (or specimen size) is smaller than a representative volume element and the moduli depend on the size of that region and boundary conditions. Both the bone tissue forming the network and the pores (represented by a very soft material) are assumed, for simplicity, as homogeneous, linear elastic, and isotropic. In order to investigate the effects of scale and boundary conditions on the moduli of these networks we vary the specimen size and apply four different boundary conditions: displacement, traction, mixed, and periodic. The analysis using periodic boundary conditions gives the effective moduli, while the displacement, traction, and mixed boundary conditions give apparent moduli. The apparent moduli calculated using displacement and traction boundary conditions bound the effective moduli from above and below, respectively. The larger is the size of the region used in our calculations, the closer are the bounds. Our choice of mixed boundary conditions gives results that are very close to those obtained using periodic boundary conditions. We conduct this analysis computationally using a finite element method. We also investigate the effect of mismatch in elastic moduli of bone tissue and soft fill, trabecular bone structure geometry, and bone tissue volume fraction on the apparent elastic moduli of idealized periodic models of trabecular bone. This study gives guidance on how the size of the specimen and boundary conditions (used in experiments or simulations) influence elastic moduli of cellular materials. This approach is applicable to heterogeneous materials in general.
Characterization of focused-ion-beam induced defect structures in graphite for the future guided self-assembly of molecules
Authors: O’Donnell Sarah E. , Reinke Petra
Published: September 2009

The morphology and periodicity of arrays of single focused-ion-beam induced artificial defects in graphite is probed using scanning tunneling microscopy and modeled through Monte Carlo simulation. While ion dose is kept constant with a fluence of 2.48×1015 ions cm−2, variations in artificial defect morphology are attributed to astigmatism in the beam aperture, to deviation in beam angle, or to distance from beam focal point. Simulation of the collision cascade of the ion in graphite lattice correlates to the artificial defect dimensions of both circular symmetric and elongated asymmetric defects. Periodic arrays of artificial defects exhibit constant periodicities at lower basis dimensions (100 nm separation between defects), with larger deviations from the periodic structure at higher basis dimensions (400 nm separation between defects). Well structured periodic arrays of defects are considered for nanostructured patterning of molecules for thin film growth. Local amorphization of graphite due to ion irradiation changes the diffusion field, which can be tailored for the guided self-assembly of molecules.
The Last Glacial Maximum
Authors: Clark Peter U. , Dyke Arthur S. , Shakun Jeremy D. , Carlson Anders E. , Clark Jorie , Wohlfarth Barbara , Mitrovica Jerry X. , Hostetler Steven W. , McCabe A. Marshall
Published: September 2009

The Melting Is in the Details

Global sea level rises and falls as ice sheets and glaciers melt and grow, providing an integrated picture of the changes in ice volume but little information about how much individual ice fields are contributing to those variations. Knowing the regional structure of ice variability during glaciations and deglaciations will clarify the mechanisms of the glacial cycle.

Clark
et al.

(p.
710
) compiled and analyzed more than 5000 radiocarbon and cosmogenic surface exposure ages in order to develop a record of maximum regional ice extent around the time of the Last Glacial Maximum. The responses of the Northern and Southern Hemispheres differed significantly, which reveals how the evolution of specific ice sheets affected sea level and provides insight into how insolation controlled the deglaciation.
Unexpected Epoxide Formation in the Gas-Phase Photooxidation of Isoprene
Authors: Paulot Fabien , Crounse John D. , Kjaergaard Henrik G. , Kürten Andreas , St. Clair Jason M. , Seinfeld John H. , Wennberg Paul O.
Published: September 2009

No NO

Isoprene, a five-carbon diene produced by plants, is the most abundant nonmethane hydrocarbon released into the atmosphere and plays an important role in tropospheric chemistry. Isoprene is also thought to affect climate by acting as a source of atmospheric aerosols.

Paulot
et al.

(p.
730
; see the Perspective by

Kleindienst

) now describe how isoprene may lead to the formation of secondary organic aerosols. In laboratory experiments, the photooxidation of isoprene in low-NO conditions, such as those which occur in vegetated regions far from anthropogenic influence, produced high yields of dihydroxy epoxides, a suspected precursor of the aerosols. This discovery could help to explain some of the more puzzling aspects of isoprene chemistry in remote regions.
Ecological Dynamics Across the Arctic Associated with Recent Climate Change
Authors: Post Eric , Forchhammer Mads C. , Bret-Harte M. Syndonia , Callaghan Terry V. , Christensen Torben R. , Elberling Bo , Fox Anthony D. , Gilg Olivier , Hik David S. , Høye Toke T. , Ims Rolf A. , Jeppesen Erik , Klein David R. , Madsen Jesper , McGuire A. David , Rysgaard Søren , Schindler Daniel E. , Stirling Ian , Tamstorf Mikkel P. , Tyler Nicholas J.C. , van der Wal Rene , Welker Jeffrey , Wookey Philip A. , Schmidt Niels Martin , Aastrup Peter
Published: September 2009

Assessing the Arctic

The Arctic is experiencing some of the most rapid climate change currently under way across the globe, but consequent ecological responses have not been widely reported. At the close of the Fourth International Polar Year,

Post
et al.

(p.
1355
) review observations on ecological impacts in this sensitive region. The widespread changes occurring in terrestrial, freshwater, and marine systems, presage changes at lower latitudes that will affect natural resources, food production, and future climate buffering.
The Thermodynamics of Quantum Critical Points
Authors: Fisk Zachary
Published: September 2009

Thermodynamic signatures have been obtained for phase transitions that occur as temperatures approach absolute zero.
MITEs—The Ultimate Parasites
Authors: González Josefa , Petrov Dmitri
Published: September 2009

How do genomic parasites called MITEs accumulate in large numbers in plant genomes?
A Race Against Time to Vaccinate Against Novel H1N1 Virus
Authors: Cohen Jon
Published: September 2009

On 24 August, the White House released a report about the swine flu pandemic from a group of prominent scientists commissioned by U.S. President Barack Obama that made a stir because it highlighted a "plausible scenario" that the novel H1N1 virus could infect up to half the U.S. population in the next 6 months and kill as many as 90,000 people, most of them young.
Salmonella enterica
Serovar Typhi-Specific Immunoglobulin A Antibody Responses in Plasma and Antibody in Lymphocyte Supernatant Specimens in Bangladeshi Patients with Suspected Typhoid Fever
Authors: Sheikh Alaullah , Bhuiyan M. Saruar , Khanam Farhana , Chowdhury Fahima , Saha Amit , Ahmed Dilruba , Jamil K. M. A. , LaRocque Regina C. , Harris Jason B. , Ahmad Mian Mashhud , Charles Richelle , Brooks W. Abdullah , Calderwood Stephen B. , Cravioto Alejandro , Ryan Edward T. , Qadri Firdausi
Published: September 2009

Many currently available diagnostic tests for typhoid fever lack sensitivity and/or specificity, especially in areas of the world where the disease is endemic. In order to identify a diagnostic test that better correlates with typhoid fever, we evaluated immune responses to
Salmonella enterica
serovar Typhi (serovar Typhi) in individuals with suspected typhoid fever in Dhaka, Bangladesh. We enrolled 112 individuals with suspected typhoid fever, cultured day 0 blood for serovar Typhi organisms, and performed Widal assays on days 0, 5, and 20. We harvested peripheral blood lymphocytes and analyzed antibody levels in supernatants collected on days 0, 5, and 20 (using an antibody-in-lymphocyte-supernatant [ALS] assay), as well as in plasma on these days. We measured ALS reactivity to a serovar Typhi membrane preparation (MP), a formalin-inactivated whole-cell preparation, and serovar Typhi lipopolysaccharide. We measured responses in healthy Bangladeshi, as well as in Bangladeshi febrile patients with confirmed dengue fever or leptospirosis. We categorized suspected typhoid fever individuals into different groups (groups I to V) based on blood culture results, Widal titer, and clinical features. Responses to MP antigen in the immunoglobulin A isotype were detectable at the time of presentation in the plasma of 81% of patients. The ALS assay, however, tested positive in all patients with documented or highly suspicious typhoid, suggesting that such a response could be the basis of improved diagnostic point-of-care-assay for serovar Typhi infection. It can be important for use in epidemiological studies, as well as in difficult cases involving fevers of unknown origin.
Comparison of Three Reference Methods for Testing Susceptibility of Staphylococci to Trimethoprim-Sulfamethoxazole
Authors: Griffith R. , Creely D. , Revell P. , Dunne W. Michael , Shortridge D.
Published: September 2009

Three reference MIC methods approved by the Clinical and Laboratory Standards Institute were compared by testing 567 staphylococci against trimethoprim-sulfamethoxazole. Category agreement ranged from 94.9% (broth macrodilution versus broth microdilution) to 98.6% (agar dilution versus broth microdilution). Twenty-seven strains resistant by broth macrodilution were susceptible by broth microdilution.
Preliminary Evaluation of the Br
EMA1
Gene as a Tool for Associating
Babesia rossi
Genotypes and Clinical Manifestation of Canine Babesiosis
Authors: Matjila P. T. , Carcy B. , Leisewitz A. L. , Schetters T. , Jongejan F. , Gorenflot A. , Penzhorn B. L.
Published: September 2009

Babesia rossi
, an intraerythrocytic protozoan, causes a severe, often life-threatening disease of domestic dogs. Dogs treated early for
B. rossi
infection usually recover from the disease, but dogs left untreated or treated at a later stage of infection seldom survive. Dogs infected with
B. rossi
have varied clinical manifestations that can be categorized as uncomplicated (with a good prognosis) or complicated (with a poor prognosis). One hundred twenty-one blood samples were collected from dogs presented to the Onderstepoort Veterinary Academic Hospital and diagnosed with babesiosis by the use of a thin blood smear. An additional 20 samples were obtained from
Babesia
-infected dogs from private clinics around the Onderstepoort, Johannesburg, Durban, White River, and Cape Town areas. The samples were screened by PCR targeting the
Babesia rossi
erythrocyte membrane antigen gene (Br
EMA1
) and by sequencing of the polymorphic region (i.e., region with a variable number of hexapeptide repeats). Analysis of PCR products revealed 11 different gene profiles, visualized by gel electrophoresis. Twelve distinct Br
EMA1
genotypes were identified by sequencing, but the numbers of hexapeptide repeats varied from 6 to 31 (classified as genotype6 to genotype31). The genotypes were retrospectively compared to the clinical case data. The most frequently encountered
B. rossi
parasites were those attributed to genotype19 (36.2%), genotype28 and genotype29 (20.6% each), and genotype11 (12.7%). These genotypes were also the ones associated with the poorest prognosis. This preliminary finding suggests clinically important differences between the various
B. rossi
genotypes identified.
Detection of PrP
sc
in Blood from Sheep Infected with the Scrapie and Bovine Spongiform Encephalopathy Agents
Authors: Terry L. A. , Howells L. , Hawthorn J. , Edwards J. C. , Moore S. J. , Bellworthy S. J. , Simmons H. , Lizano S. , Estey L. , Leathers V. , Everest S. J.
Published: September 2009

The role of blood in the iatrogenic transmission of transmissible spongiform encephalopathy (TSE) or prion disease has become an increasing concern since the reports of variant Creutzfeldt-Jakob disease (vCJD) transmission through blood transfusion from humans with subclinical infection. The development of highly sensitive rapid assays to screen for prion infection in blood is of high priority in order to facilitate the prevention of transmission via blood and blood products. In the present study we show that PrP
sc
, a surrogate marker for TSE infection, can be detected in cells isolated from the blood from naturally and experimentally infected sheep by using a rapid ligand-based immunoassay. In sheep with clinical disease, PrP
sc
was detected in the blood of 55% of scrapie agent-infected animals (
n
= 80) and 71% of animals with bovine spongiform encephalopathy (
n
= 7). PrP
sc
was also detected several months before the onset of clinical signs in a subset of scrapie agent-infected sheep, followed from 3 months of age to clinical disease. This study confirms that PrP
sc
is associated with the cellular component of blood and can be detected in preclinical sheep by an immunoassay in the absence of in vitro or in vivo amplification.
The Endoplasmic Reticulum Chaperone BiP/GRP78 Is Important in the Structure and Function of the Human Cytomegalovirus Assembly Compartment
Authors: Buchkovich Nicholas J. , Maguire Tobi G. , Paton Adrienne W. , Paton James C. , Alwine James C.
Published: September 2009

We previously demonstrated that the endoplasmic reticulum (ER) chaperone BiP functions in human cytomegalovirus (HCMV) assembly and egress. Here, we show that BiP localizes in two cytoplasmic structures in infected cells. Antibodies to the extreme C terminus, which includes BiP's KDEL ER localization sequence, detect BiP in regions of condensed ER near the periphery of the cell. Antibodies to the full length, N terminus, or larger portion of the C terminus detect BiP in the assembly compartment. This inability of C-terminal antibodies to detect BiP in the assembly compartment suggests that BiP's KDEL sequence is occluded in the assembly compartment. Depletion of BiP causes the condensed ER and assembly compartments to dissociate, indicating that BiP is important for their integrity. BiP and pp28 are in association in the assembly compartment, since antibodies that detect BiP in the assembly compartment coimmunoprecipitate pp28 and vice versa. In addition, BiP and pp28 copurify with other assembly compartment components on sucrose gradients. BiP also coimmunoprecipitates TRS1. Previous data show that cells infected with a TRS1-deficient virus have cytoplasmic and assembly compartment defects like those seen when BiP is depleted. We show that a fraction of TRS1 purifies with the assembly compartment. These findings suggest that BiP and TRS1 share a function in assembly compartment maintenance. In summary, BiP is diverted from the ER to associate with pp28 and TRS1, contributing to the integrity and function of the assembly compartment.
Akt Inhibitor Akt-IV Blocks Virus Replication through an Akt-Independent Mechanism
Authors: Dunn Ewan F. , Fearns Rachel , Connor John H.
Published: September 2009

Many viruses activate the phosphatidylinositol 3′-kinase (PI3k)/Akt intracellular signaling pathway to promote viral replication. We have analyzed whether a rapidly replicating rhabdovirus, vesicular stomatitis virus (VSV), requires the PI3k/Akt signaling pathway for its replication. Through the use of chemical inhibitors of PI3k and Akt, we show that VSV replication and cytopathic effects do not require activation of these kinases. Inhibitors that block the activating phosphorylations of Akt at threonine 308 (Thr308) and serine 473 (Ser473) did not inhibit VSV protein expression or the induction of the cytopathic effects of VSV. One compound, Akt inhibitor Akt-IV, inhibited the replication of VSV, respiratory syncytial virus, and vaccinia virus but increased the phosphorylation of Akt at positions Thr308 and Ser473 and did not inhibit Akt kinase activity in vitro. Together, our data suggest that the PI3k/Akt pathway is of limited relevance to the replication of VSV but that Akt inhibitor Akt-IV is a novel broad-spectrum antiviral compound with a mechanism differing from that of its previously reported effect on the PI3k/Akt pathway. Identification of other targets for this compound may define a new approach for blocking virus replication.