bluuebunny/crossref_metadata_2025 huggingface dataset:
“The Glass Ceiling Is Kind of a Bummer”: Women’s Reflections on a Gender Development Course
Authors: Sharp Elizabeth A. , SoRelle‐Miner Danielle , Bermudez Judith M. , Walker Maria
Published: September 2008

Abstract: The purpose of this study was to explore women students’ experiences and reactions to a core Human Development and Family Studies (HDFS) class cross‐listed with Women’s Studies (WS). Using 6 focus groups with 22 women, we found that the course increased awareness of gender (Theme A) but was limited partially because of patriarchical beliefs, evidenced by acceptance of sexism (Theme B) and men as central (Theme C). The beliefs were manifested in how students interacted with course material, which was predominately through rejection of the course (Theme D). Using skill theory framework, we explain our findings through the interplay of the environment and students’ cognitive skills. Implications for HDFS/Women’s Studies cross‐listed courses are discussed.
Different roles of two γ‐tubulin isotypes in the cytoskeleton of the Antarctic ciliate Euplotes focardii
Authors: Marziale Francesca , Pucciarelli Sandra , Ballarini Patrizia , Melki Ronald , Uzun Alper , Ilyin Valentin A. , Detrich III H. W. , Miceli Cristina
Published: September 2008

γ‐Tubulin belongs to the tubulin superfamily and plays an essential role in the nucleation of cellular microtubules. In the present study, we report the characterization of γ‐tubulin from the psychrophilic Antarctic ciliate Euplotes focardii. In this organism, γ‐tubulin is encoded by two genes, γ‐T1 and γ‐T2, that produce distinct isotypes. Comparison of the γ‐T1 and γ‐T2 primary sequences to a Euplotesγ‐tubulin consensus, derived from mesophilic (i.e. temperate) congeneric species, revealed the presence of numerous unique amino acid substitutions, particularly in γ‐T2. Structural models of γ‐T1 and γ‐T2, obtained using the 3D structure of human γ‐tubulin as a template, suggest that these substitutions are responsible for conformational and/or polarity differences located: (a) in the regions involved in longitudinal ‘plus end’ contacts; (b) in the T3 loop that participates in binding GTP; and (c) in the M loop that forms lateral interactions. Relative to γ‐T1, the γ‐T2 gene is amplified by approximately 18‐fold in the macronuclear genome and is very strongly transcribed. Using confocal immunofluorescence microscopy, we found that the γ‐tubulins of E. focardii associate throughout the cell cycle with basal bodies of the non‐motile dorsal cilia and of all of the cirri of the ventral surface (i.e. adoral membranelles, paraoral membrane, and frontoventral transverse, caudal and marginal cirri). By contrast, only γ‐T2 interacts with the centrosomes of the spindle during micronuclear mitosis. We also established that the γ‐T1 isotype associates only with basal bodies. Our results suggest that γ‐T1 and γ‐T2 perform different functions in the organization of the microtubule cytoskeleton of this protist and are consistent with the hypothesis that γ‐T1 and γ‐T2 have evolved sequence‐based structural alterations that facilitate template nucleation of microtubules by the γ‐tubulin ring complex at cold temperatures.
Fractional derivative approach to the self-gravitation equation
Authors: Pedraza Juan F. , Ramos-Caro Javier F. , González Guillermo A.
Published: September 2008

A new formalism is presented for finding the equilibrium distribution functions for axisymmetric systems. The formalism, obtained by using the concept of fractional derivatives, generalizes the methods of Fricke, Kalnajs and Jiang & Ossipkov, and has the advantage that can be applied to a wide variety of models. We found that this approach can be applied to both tridimensional systems and flat systems, without the necessity of dealing with a pseudo-volume mass density. As an application, we obtain the distribution functions of the Binney's logarithmic model, the Mestel disc and the stellar dynamical tori introduced by Ciotti et al. in 2004.
Stopping the Revolving Door: Increasing Teacher Retention
Authors: Brill Sam , McCartney Abby
Published: September 2008

Schools around the nation are facing an alarming phenomenon: beginning teachers are leaving schools at a startling rate. Thirty‐three percent of teachers leave their schools in the first three years, 46 percent after five years. These high attrition rates result in inexperienced teachers, high economic costs as teachers must be continually hired and trained, and a lack of continuity that makes institutional development and planning difficult. There is a plethora of causes for teacher attrition, although most involve nonsalary‐related dissatisfaction, such as excessive workloads and high‐stakes testing, disruptive student behavior, poor leadership and administration within schools, and views of teaching as a temporary profession. Likewise, the most successful remedies to increase teacher retention are not salary‐based. Several studies have found that moderate salary increases are only marginally effective; raises of 20 percent would be needed to make a significant impact. Rather, improving teachers' work environment and professional development are more cost effective and influential in convincing teachers to remain. An induction and mentoring program in California, for example, reduced teacher attrition by 26 percent in just two years. We conclude, therefore, that well‐operated induction and mentoring programs are the best method for increasing teacher retention.
U.S. Energy Policy Response to International Food Prices: The Costs and Effects of Corn Ethanol Production1
Authors: Waage Eric
Published: September 2008

Following a decade of relatively low food prices, the U.S. Congress has responded to internal and external political pressure by offering economic incentives for domestic corn‐based ethanol production. The Food, Conservation, and Energy Act of 2008, however, contains no provisions for long‐term protection of corn ethanol producers and attempts to develop the infrastructure necessary to shift the current corn‐ethanol supply to the market. This paper traces the underlying causes of this policy reversal, focusing on the effect of diverted corn supply on retail food inflation and the subsequent response from domestic and international consumers. It explains the mechanisms that determine corn prices in the United States and prices in other industries, and shows the positive effect of global ethanol production on international food prices. In light of increasing costs and shifting political preferences, a diversified biofuel portfolio should emerge in the medium term, which would alleviate the current strain on food supply and stabilize inflation. To facilitate a smooth transition from corn ethanol production to that of more sustainable forms of renewable energy, Congress should continue to invest in emerging energy industries, while negotiating with domestic producers and foreign governments for long‐term reductions in food and energy subsidies.
Are We Really Ready? The Need for National Emergency Preparedness Standards and the Creation of the Cycle of Emergency Planning1
Authors: Bowen Ashley A.
Published: September 2008

A review of the Department of Homeland Security's (DHS) policies and recent performance reveals major weaknesses in the nation's preparedness for protecting against and responding to terrorist attacks and natural disasters. Research has shown that the DHS currently lacks national standards for the review and maintenance of emergency plans, the frequency of emergency drills, and the review of results from such drills. This policy proposes the standardization of emergency exercises and the creation of the cycle of emergency planning (CEP), with DHS funding contingent on implementation of these national standards. This article addresses how the implementation of the CEP would provide a method for testing, revising, and maintaining emergency preparedness through review, exercises, and revision. Holding emergency exercises every two years and reviewing their results would help keep plans current and grounded in feasibility. Reviews of emergency plans and capabilities, conducted every five years by a third party, would help maintain objectivity. These exercises and reviews should be used to update and maintain emergency plans as part of the CEP. Enforcing these new standards would remedy the failures in the current emergency preparedness system and improve the general safety and security of the nation.
Reforming Subsidies in the Federal Budget
Authors: Dever Jr. Patrick
Published: September 2008

The U.S. government spent approximately $52.52 billion in subsidies in 2006, yet many of these subsidies actually reduce social welfare because of a lack of information and political lobbying by influential interest groups and coalitions. Through detailed analysis of economic markets, this report illustrates the economic effects of both proper and improper subsidies and proposes the creation of an independent Subsidy Review Board (SRB). This two‐tiered board with offices representing different sectors of the U.S. economy would evaluate subsidies at the industrial and national level under the specific economic criteria established in this report. This proposal would eliminate information asymmetry problems because the information costs of evaluating subsidies would be shifted away from time‐constrained politicians to the SRB, staffed with economists whose sole responsibility is to evaluate these subsidies. Furthermore, an independent board would not be as susceptible to political or socioeconomic pressures as individual legislators. A reformation of the federal subsidy process would eliminate billions of dollars from the federal budget each year and direct better allocation of the remaining taxpayer funds.
The Role of Vocational Training in Pathways toward Desistance
Authors: Feeney Kevin Joseph
Published: September 2008

This essay explores the relationship between vocational training and prisoner entry, a process that attempts to facilitate and support formerly incarcerated people's (FIP's) efforts to establish lives free from crime. I draw from a review of existing programs and an analysis of the relationship between work and crime to derive the conclusion that vocational training should take innovative steps in order to prepare FIP to compete effectively in the contemporary labor market. Training should address the barriers to long‐term employment that are particular to FIP. It should also enable these individuals to treat their work as a transformative moment in the path toward desistance. I close by evaluating the potential of two innovative models of vocational programs, both of which appear to satisfy the criteria established above.
Mitochondrial DNA sequence analyses in Bornean sucker fishes (Balitoridae: Teleostei: Gastromyzontinae)
Authors: SULAIMAN Zohrah Haji , HUI Tan Heok , LIM Kelvin K.P. , NG Peter K.L.
Published: September 2008

Phylogenetic relationships among Bornean sucker fishes (Teleostei: Balitoridae: Gastromyzontinae) were investigated by comparing cytochrome b gene sequences from eight species. The results were in general agreement with previous morphology‐based studies. It was found that the genera Gastromyzon and Neogastromyzon are both monophyletic and that the Chinese homalopterid Crossostoma lacustre (Homalopterinae) is not related to the Bornean species. This molecular‐level study of cytochrome b gene variation in Bornean gastromyzontins will undoubtedly help to shed light on the molecular systematics of this unique freshwater fish.
Towards an index of all known species: the Catalogue of Life, its rationale, design and use
Authors: CACHUELA‐PALACIO Monalisa
Published: September 2008

The Catalogue of Life, created by Species 2000 and the Integrated Taxonomic Information System, has the ambitious aim of creating a uniform and validated index of the world's known species for use as a practical tool in inventorying and monitoring biodiversity worldwide. This is achieved by accessing an array of taxonomic databases created and made available by individual, project and institutional custodians through taxonomic and biodiversity initiatives. A standard data set is delivered for every known species, drawn from Species 2000 contributing databases. Data are provided to the Species 2000 Philippine office, compiled annually and published in CD‐ROM format. Species 2000 also includes the Species Locator Service, which gives a responsible opinion as to the actual species currently recognized by taxonomists and their accepted names, and the Name Service that assists users in checking the spelling and original publication details for a wider range of names, including species not yet incorporated in the Species Locator Service. The Species Locator Service is available as the Dynamic Checklist, which is used to search for the scientific name of an organism online, and the Annual Checklist, which is a stable index produced once a year and is available on CD‐ROM and online. Catalogue of Life currently covers more than 272 000 species and 32 000 infraspecies, with 181 000 synonyms. It has 217 000 common names, 87 000 references and 20 contributing databases that encompass all known animals, plants, fungi and microorganisms.
Brief report on the status of Kozlov's pika, Ochotona koslowi (Büchner), in the east Kunlun mountains of China
Authors: LI Weidong , ZHANG Huibin , LIU Zhihu
Published: September 2008

Koslov's pika, Ochotona koslowi (Büchner), was surveyed in western China. This endangered species is poorly known. We determined that it is a burrowing pika, and lives in social family groups at high densities. It primarily occupies high‐elevation cold grassland vegetation. It appears to have a high reproductive rate. More emphasis should be placed on research into this unique species in China.
The actuality of Lamarck: towards the bicentenary of his Philosophic Zoologique
Authors: POR Francis Dov
Published: September 2008

Lamarck, a son of the age of natural philosophy and revolutionary ideas, turned to zoology, the field in which he made his major impact, in his old age. By then, the world had already shifted towards a different intellectual atmosphere and, due to this anachronism, he was snubbed and even ridiculed by the mainstream neo‐Darwinists. Yet his basic ideas about the active role of organisms in and the progressive unraveling of evolution stubbornly survived along the academic fringes and, more importantly, among the humanistic writers. Recent developments in genetic inheritance, embryology, immunology and behavioral studies vindicate, at least in part, the 200‐year‐old vision of Lamarck.
Spectral numbers in Floer theories
Authors: Usher Michael
Published: September 2008

The chain complexes underlying Floer homology theories typically carry a real-valued filtration, allowing one to associate to each Floer homology class a spectral number defined as the infimum of the filtration levels of chains representing that class. These spectral numbers have been studied extensively in the case of Hamiltonian Floer homology by Oh, Schwarz and others. We prove that the spectral number associated to any nonzero Floer homology class is always finite, and that the infimum in the definition of the spectral number is always attained. In the Hamiltonian case, this implies that what is known as the ‘nondegenerate spectrality’ axiom holds on all closed symplectic manifolds. Our proofs are entirely algebraic and apply to any Floer-type theory (including Novikov homology) satisfying certain standard formal properties. The key ingredient is a theorem about the existence of best approximations of arbitrary elements of finitely generated free modules over Novikov rings by elements of prescribed submodules with respect to a certain family of non-Archimedean metrics.
Lakshmibai–Seshadri paths of level-zero shape and one-dimensional sums associated to level-zero fundamental representations
Authors: Naito Satoshi , Sagaki Daisuke
Published: September 2008

We give an interpretation of the energy function and classically restricted one-dimensional sums associated to tensor products of level-zero fundamental representations of quantum affine algebras in terms of Lakshmibai–Seshadri paths of level-zero shape.
A critical GxxxA motif in the γ6 calcium channel subunit mediates its inhibitory effect on Cav3.1 calcium current
Authors: Lin Zuojun , Witschas Katja , Garcia Thomas , Chen Ren‐Shiang , Hansen Jared P. , Sellers Zachary M. , Kuzmenkina Elza , Herzig Stefan , Best Philip M.
Published: September 2008

The eight members of the calcium channel γ subunit family are integral membrane proteins that regulate the expression and behaviour of voltage and ligand gated ion channels. While a subgroup consisting of γ2, γ3, γ4 and γ8 (the TARPs) modulate AMPA receptor localization and function, the γ1 and γ6 subunits conform to the original description of these proteins as regulators of voltage gated calcium channels. We have previously shown that the γ6 subunit is highly expressed in atrial myocytes and that it is capable of acting as a negative modulator of low voltage activated calcium current. In this study we extend our understanding of γ6 subunit modulation of low voltage activated calcium current. Using engineered chimeric constructs, we demonstrate that the first transmembrane domain (TM1) of γ6 is necessary for its inhibitory effect on Cav3.1 current. Mutational analysis is then used to identify a unique GxxxA motif within TM1 that is required for the function of the subunit strongly suggesting the involvement of helix–helix interactions in its effects. Results from co‐immunoprecipitation experiments confirm a physical association of γ6 with the Cav3.1 channel in both HEK cells and atrial myocytes. Single channel analysis reveals that binding of γ6 reduces channel availability for activation. Taken together, the results of this study provide both a molecular and a mechanistic framework for understanding the unique ability of the γ6 calcium channel subunit to modulate low voltage activated (Cav3.1) calcium current density.
Co‐expression of IGF‐1 family members with myogenic regulatory factors following acute damaging muscle‐lengthening contractions in humans
Authors: McKay Bryon R. , O'Reilly Ciara E. , Phillips Stuart M. , Tarnopolsky Mark A. , Parise Gianni
Published: September 2008

Muscle regeneration following injury is dependent on the ability of muscle satellite cells to activate, proliferate and fuse with damaged fibres. This process is controlled by the myogenic regulatory factors (MRF). Little is known about the temporal relation of the MRF with the expression of known myogenic growth factors (i.e. IGF‐1) in humans following muscle damage. Eight subjects (20.6 ± 2.1 years; 81.4 ± 9.8 kg) performed 300 lengthening contractions (180 deg s−1) of their knee extensors in one leg on a dynamometer. Blood and muscle samples were collected before and at 4 (T4), 24 (T24), 72 (T72) and 120 h (T120) post‐exercise. Mechano growth factor (MGF), IGF‐1Ea and IGF‐1Eb mRNA were quantified. Serum IGF‐1 did not change over the post‐exercise time course. IGF‐1Ea and IGF‐1Eb mRNA increased ∼4‐ to 6‐fold by T72 (P < 0.01) and MGF mRNA expression peaked at T24 (P= 0.005). MyoD mRNA expression increased ∼2‐fold at T4 (P < 0.05). Myf5 expression peaked at T24 (P < 0.05), while MRF4 and myogenin mRNA expression peaked at T72 (P < 0.05). Myf5 expression strongly correlated with the increase in MGF mRNA (r2= 0.83; P= 0.03), while MRF4 was correlated with both IGF‐1Ea and ‐Eb (r2= 0.90; r2= 0.81, respectively; P < 0.05). Immunofluorescence analysis showed IGF‐1 protein expression localized to satellite cells at T24, and to satellite cells and the myofibre at T72 and T120; IGF‐1 was not detected at T0 or T4. These results suggest that the temporal response of MGF is probably related to the activation/proliferation phase of the myogenic programme as marked by an increase in both Myf5 and MyoD, while IGF‐1Ea and ‐Eb may be temporally related to differentiation as marked by an increase in MRF4 and myogenin expression following acute muscle damage.
Sympathetic‐induced changes in discharge rate and spike‐triggered average twitch torque of low‐threshold motor units in humans
Authors: Roatta Silvestro , Arendt‐Nielsen Lars , Farina Dario
Published: September 2008

Animal and in vitro studies have shown that the sympathetic nervous system modulates the contractility of skeletal muscle fibres, which may require adjustments in the motor drive to the muscle in voluntary contractions. In this study, these mechanisms were investigated in the tibialis anterior muscle of humans during sympathetic activation induced by the cold pressor test (CPT; left hand immersed in water at 4°C). In the first experiment, 11 healthy men performed 20 s isometric contractions at 10% of the maximal torque, before, during and after the CPT. In the second experiment, 12 healthy men activated a target motor unit at the minimum stable discharge rate for 5 min in the same conditions as in experiment 1. Intramuscular electromyographic (EMG) signals and torque were recorded and used to assess the motor unit discharge characteristics (experiment 1) and spike‐triggered average twitch torque (experiment 2). CPT increased the diastolic blood pressure and heart rate by (mean ±s.d.) 18 ± 9 mmHg and 4.7 ± 6.5 beats min−1 (P < 0.01), respectively. In experiment 1, motor unit discharge rate increased from 10.4 ± 1.0 pulses s−1 before to 11.1 ± 1.4 pulses s−1 (P < 0.05) during the CPT. In experiment 2, the twitch half‐relaxation time decreased by 15.8 ± 9.3% (P < 0.05) during the CPT with respect to baseline. These results provide the first evidence of an adrenergic modulation of contractility of muscle fibres in individual motor units in humans, under physiological sympathetic activation.
Endothelium‐dependent contractions: when a good guy turns bad!
Authors: Vanhoutte Paul M. , Tang Eva H. C.
Published: September 2008

Endothelial cells can induce contractions of the underlying vascular smooth muscle by generating vasoconstrictor prostanoids (endothelium‐dependent contracting factor; EDCF). The endothelial COX‐1 isoform of cyclooxygenase appears to play the dominant role in the phenomenon. Its activation requires an increase in intracellular Ca2+concentration. The production of EDCF is inhibited acutely and chronically by nitric oxide (NO), and possibly by endothelium‐dependent hyperpolarizing factor (EDHF). The main prostanoids involved in endothelium‐dependent contractions appear to be endoperoxides (PGH2) and prostacyclin, which activate thromboxane‐prostanoid (TP) receptors of the vascular smooth muscle cells. Oxygen‐derived free radicals can facilitate the production and/or the action of EDCF. Endothelium‐dependent contractions are exacerbated by ageing, obesity, hypertension and diabetes, and thus are likely to contribute to the endothelial dysfunction observed in older people and in essential hypertensive patients.
The Structure and Dynamics of Mid-Ocean Ridge Hydrothermal Systems
Authors: Coumou D. , Driesner T. , Heinrich C. A.
Published: September 2008

Sub-seafloor hydrothermal convection at mid-ocean ridges transfers 25% of the Earth's heat flux and can form massive sulfide ore deposits. Their three-dimensional (3D) structure and transient dynamics are uncertain. Using 3D numerical simulations, we demonstrated that convection cells self-organize into pipelike upflow zones surrounded by narrow zones of focused and relatively warm downflow. This configuration ensures optimal heat transfer and efficient metal leaching for ore-deposit formation. Simulated fluid-residence times are as short as 3 years. The concentric flow geometry results from nonlinearities in fluid properties, and this may influence the behavior of other fluid-flow systems in Earth's crust.
Infants' Perseverative Search Errors Are Induced by Pragmatic Misinterpretation
Authors: Topál József , Gergely György , Miklósi Ádám , Erdőhegyi Ágnes , Csibra Gergely
Published: September 2008

Having repeatedly retrieved an object from a location, human infants tend to search the same place even when they observe the object being hidden at another location. This perseverative error is usually explained by infants' inability to inhibit a previously rewarded search response or to recall the new location. We show that the tendency to commit this error is substantially reduced (from 81 to 41%) when the object is hidden in front of 10-month-old infants without the experimenter using the communicative cues that normally accompany object hiding in this task. We suggest that this improvement is due to an interpretive bias that normally helps infants learn from demonstrations but misleads them in the context of a hiding game. Our finding provides an alternative theoretical perspective on the nature of infants' perseverative search errors.
Linear Response Breakdown in Solvation Dynamics Induced by Atomic Electron-Transfer Reactions
Authors: Bragg Arthur E. , Cavanagh Molly C. , Schwartz Benjamin J.
Published: September 2008

The linear response (LR) approximation, which predicts identical relaxation rates from all nonequilibrium initial conditions that relax to the same equilibrium state, underlies dominant models of how solvation influences chemical reactivity. We experimentally tested the validity of LR for the solvation that accompanies partial electron transfer to and from a monatomic solute in solution. We photochemically prepared the species with stoichiometry Na
0
in liquid tetrahydrofuran by both adding an electron to Na
+
and removing an electron from Na
–
. Because atoms lack nuclear degrees of freedom, ultrafast changes in the Na
0
absorption spectrum reflected the solvation that began from our two initial nonequilibrium conditions. We found that the solvation of Na
0
occurs more rapidly from Na
+
than Na
–
, constituting a breakdown of LR. This indicates that Marcus theory would fail to describe electron-transfer processes for this and related chemical systems.
Neodymium-142 Evidence for Hadean Mafic Crust
Authors: O'Neil Jonathan , Carlson Richard W. , Francis Don , Stevenson Ross K.
Published: September 2008

Neodymium-142 data for rocks from the Nuvvuagittuq greenstone belt in northern Quebec, Canada, show that some rock types have lower
142
Nd/
144
Nd ratios than the terrestrial standard (ϵ
142
Nd = –0.07 to –0.15). Within a mafic amphibolite unit,
142
Nd/
144
Nd ratios correlate positively with Sm/Nd ratios and produce a
146
Sm-
142
Nd isochron with an age of

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million years. These rocks thus sample incompatible-element-enriched material formed shortly after Earth formation and may represent the oldest preserved crustal section on Earth.
Conservation and Rewiring of Functional Modules Revealed by an Epistasis Map in Fission Yeast
Authors: Roguev Assen , Bandyopadhyay Sourav , Zofall Martin , Zhang Ke , Fischer Tamas , Collins Sean R. , Qu Hongjing , Shales Michael , Park Han-Oh , Hayles Jacqueline , Hoe Kwang-Lae , Kim Dong-Uk , Ideker Trey , Grewal Shiv I. , Weissman Jonathan S. , Krogan Nevan J.
Published: September 2008

An epistasis map (E-MAP) was constructed in the fission yeast,
Schizosaccharomyces pombe
, by systematically measuring the phenotypes associated with pairs of mutations. This high-density, quantitative genetic interaction map focused on various aspects of chromosome function, including transcription regulation and DNA repair/replication. The E-MAP uncovered a previously unidentified component of the RNA interference (RNAi) machinery (
rsh1
) and linked the RNAi pathway to several other biological processes. Comparison of the
S. pombe
E-MAP to an analogous genetic map from the budding yeast revealed that, whereas negative interactions were conserved between genes involved in similar biological processes, positive interactions and overall genetic profiles between pairs of genes coding for physically associated proteins were even more conserved. Hence, conservation occurs at the level of the functional module (protein complex), but the genetic cross talk between modules can differ substantially.
Regime Change in Scientific Depiction
Authors: Richardson Alan
Published: September 2008

Objectivity
.
By Lorraine Daston and Peter Galison
. Zone, New York, 2007. 504 pp. $38.95, £25.95. ISBN 9781890951788.

The authors explore changes in the meanings of objectivity through a consideration of images, in particular those from scientific atlases and reference books.
Evolution of Block Copolymer Lithography to Highly Ordered Square Arrays
Authors: Tang Chuanbing , Lennon Erin M. , Fredrickson Glenn H. , Kramer Edward J. , Hawker Craig J.
Published: September 2008

The manufacture of smaller, faster, more efficient microelectronic components is a major scientific and technological challenge, driven in part by a constant need for smaller lithographically defined features and patterns. Traditional self-assembling approaches based on block copolymer lithography spontaneously yield nanometer-sized hexagonal structures, but these features are not consistent with the industry-standard rectilinear coordinate system. We present a modular and hierarchical self-assembly strategy, combining supramolecular assembly of hydrogen-bonding units with controlled phase separation of diblock copolymers, for the generation of nanoscale square patterns. These square arrays will enable simplified addressability and circuit interconnection in integrated circuit manufacturing and nanotechnology.
Primary Clearance of Murine Gammaherpesvirus 68 by PKCθ−/−CD8 T Cells Is Compromised in the Absence of Help from CD4 T Cells
Authors: Dias Peter , Shea Ashley L. , Inglis Chandra , Giannoni Francesca , Lee Lian Ni , Sarawar Sally R.
Published: September 2008

CD4 T cells are dispensable for acute control of murine gammaherpesvirus 68 (MHV-68) but are necessary for effective long-term control of the virus by CD8 T cells. In contrast, protein kinase C θ (PKCθ) is not essential for either acute or long-term viral control. However, we found that while either CD4 or CD8 T cells could mediate the clearance of MHV-68 from the lungs of PKCθ+/+mice, PKCθ−/−mice depleted of either subset failed to clear the virus. These data suggest that there are two alternative pathways for MHV-68 clearance, one dependent on CD4 T cells and the other on PKCθ. Protection mediated by the latter appears to be short-lived. These observations may help to explain the differential requirement for PKCθ in various models of CD8 T-cell activation and differences in the costimulatory requirements for acute and long-term viral control.
Identification of a Movement Protein of the
Tenuivirus
Rice Stripe Virus
Authors: Xiong Ruyi , Wu Jianxiang , Zhou Yijun , Zhou Xueping
Published: September 2008

Rice stripe virus (RSV) is the type member of the genus
Tenuivirus
. RSV has four single-stranded RNAs and causes severe disease in rice fields in different parts of China. To date, no reports have described how RSV spreads within host plants or the viral and/or host factor(s) required for tenuivirus movement. We investigated functions of six RSV-encoded proteins using
trans
-complementation experiments and biolistic bombardment. We demonstrate that NSvc4, encoded by RSV RNA4, supports the intercellular trafficking of a movement-deficient
Potato virus X
in
Nicotiana benthamiana
leaves. We also determined that upon biolistic bombardment or agroinfiltration, NSvc4:enhanced green fluorescent protein (eGFP) fusion proteins localize predominantly near or within the walls of onion and tobacco epidermal cells. In addition, the NSvc4:eGFP fusion protein can move from initially bombarded cells to neighboring cells in
Nicotiana benthamiana
leaves. Immunocytochemistry using tissue sections from RSV-infected rice leaves and an RSV NSvc4-specific antibody showed that the NSvc4 protein accumulated in walls of RSV-infected leaf cells. Gel retardation assays revealed that the NSvc4 protein interacts with single-stranded RNA in vitro, a common feature of many reported plant viral movement proteins (MPs). RSV NSvc4 failed to interact with the RSV nucleocapsid protein using yeast two-hybrid assays. Taken together, our data indicate that RSV NSvc4 is likely an MP of the virus. This is the first report describing a tenuivirus MP.
Epithelioid perineurioma: an unusual variant
Authors: Haider S A , Lemberger R J , Fisher C , McCulloch T A
Published: September 2008

An unusual epithelioid variant of perineurioma of the groin occurring in a 53-year-old man is described. The lesion appeared to be associated with a femoral nerve branch. The tumour was characterised by the presence of a syncytial proliferation of epithelioid cells, mimicking a meningioma of syncytial type. In addition there was a minor component of a conventional perineurioma. The tumour cells were EMA+, claudin-1+ and collagen type IV+. Bcl 2 was focally expressed. This case highlights the possibility of a common histogenetic pathway for meningiomas and perineuriomas. Although ultrastructural evidence of possible meningiomatous differentiation within an otherwise histologically typical perineurioma has been described, this is the first reported case of an unconventional epithelioid variant of perineurioma, histologically resembling meningioma.
Hypophosphataemia at a large academic hospital in South Africa
Authors: Hoffmann M , Zemlin A E , Meyer W P , Erasmus R T
Published: September 2008

Aim:

The aim of this study was to determine the most common causes of hypophosphataemia (⩽0.5 mmol/l) in a hospital population in order to identify patient groups at risk of developing the condition.

Methods:

The study was conducted at Tygerberg Hospital, a tertiary care centre in the Western Cape, South Africa. All patients identified with a phosphate level ⩽0.5 mmol/l during an 18-month period were included in the study. Medical records of these patients were reviewed.

Results:

Of all the requests received for serum phosphate determination by the laboratory, 2% (861 out of 45 394 requests) were ⩽0.5 mmol/l. Thirty per cent (30%; n = 189) of the patients in the study population died during their hospital stay. Most (45%; n = 278) of the patients with low phosphate levels occurred in an intensive care setting, whereas 10% (n = 63) were most likely due to refeeding, and 6% (n = 35) had neoplastic disease. Sepsis was implicated as a contributing factor in 26% (n = 162).

Conclusion:

Severe hypophosphataemia is associated with a very high mortality (30%, n = 189). Patients with a high risk of developing hypophosphataemia include those in an intensive care unit (ICU), patients suffering from neoplastic diseases, possible refeeding syndrome and septic patients. Regular phosphate determination is recommended in these patients to facilitate early diagnosis of hypophosphataemia.
Acute post-streptococcal glomerulonephritis associated with prolonged hypocomplementaemia
Authors: Payne D , Houtman P , Browning M
Published: September 2008

The case of a 6-year-old boy who presented with acute post-streptococcal glomerulonephritis is reported. C3 levels and complement alternative pathway activity remained low for at least 10 months after presentation, before returning to normal. There was no evidence of other renal disease. This case highlights that hypocomplementaemia in acute post-streptococcal glomerulonephritis may persist for several months, and that prolonged hypocomplementaemia does not exclude this diagnosis.
Overexpression of von Hippel-Lindau protein in skeletal muscles of patients with chronic obstructive pulmonary disease
Authors: Jatta K , Eliason G , Portela-Gomes G M , Grimelius L , Caro O , Nilholm L , Sirjsö A , Piehl-Aulin K , Abdel-Halim S M
Published: September 2008

Background:

A significant number of patients with chronic obstructive pulmonary disease (COPD) exhibit skeletal muscle wasting and decreased capillary area formation, which correlate with increased mortality.

Aim:

To determine the molecular mechanisms mediating decreased capillary formation in COPD.

Methods:

24 patients with COPD and 12 matching controls were recruited. Patients with COPD were classified into mild, moderate and severe groups according to GOLD (global initiative for chronic obstructive lung disease) criteria. Biopsy specimens were obtained from the tibialis anterior muscle. Fibre typing and capillary formation, together with messenger RNA (mRNA) expression of hypoxia-inducible factors (HIF1α and HIF3α), vascular endothelial growth factors (VEGF-A, VEGF-B and VEGF-C isoforms) and von Hippel-Lindau (VHL) protein, were determined. VHL expression and localisation were further studied by immunohistochemistry.

Results:

Skeletal muscle capillary formation decreased significantly with increasing disease severity. Compared with controls, a tendency to mRNA overexpression of HIF1α, HIF3α and VEGF isoforms was observed in mild and moderate COPD, which decreased at the severe stage. In contrast, skeletal muscle biopsy samples from patients with COPD exhibited significant overexpression of VHL at both the mRNA and protein level by immunohistochemistry. VHL protein was further determined to be localised to satellite cells.

Conclusions:

Overexpression of VHL was identified in the skeletal muscle of patients with COPD. Increased VHL activity may have a negative effect on transduction of the hypoxic signal and may contribute to decreased capillarisation in skeletal muscles of patients with COPD.
NADH-cytochrome b5 reductase in a Turkish family with recessive congenital methaemoglobinaemia type I: Table 1
Authors: Percy M J , Aslan D
Published: September 2008

The development of cyanosis at birth, the so-called blue baby syndrome, alerts paediatricians to the presence of congenital heart disease. In rare cases where the arterial blood gas analysis is normal the cyanosis is a consequence of methaemoglobinaemia. There are three distinct origins of methaemoglobinaemia; the presence of a haemoglobin variant, environmental toxicity and deficiency of cytochrome b5 reductase (cb5r). Two children born to two sets of first-degree related parents were cyanotic from birth. Differential diagnosis eliminated cardiac and pulmonary abnormalities. Measurement of methaemoglobin levels confirmed recessive congenital methaemoglobinaemia (RCM) and treatment with ascorbic acid was commenced. In the absence of neurological defects, type I disease was diagnosed. Sequence analysis ofCYB5R3revealed two different missense mutations (one which is novel, Ile85Ser) in the two families. Neither of the mutations was located in the FAD or the NADH binding sites of cb5r,thus supporting a diagnosis of type I disease.
Plexiform angiomyxoid myofibroblastic tumour: differential diagnosis of gastrointestinal stromal tumour in the stomach
Authors: Rau T T , Hartmann A , Dietmaier W , Schmitz J , Hohenberger W , Hofstaedter F , Katenkamp K
Published: September 2008

Mesenchymal tumours other than gastrointestinal stromal tumours are rare in the stomach. Nevertheless it is important to incorporate them into the differential diagnosis. Plexiform angiomyxoid myofibroblastic tumour is a recently described new entity of a presumably benign mesenchymal gastric tumour. This report presents what is believed to be the third case of this tumour. The tumour is characterised by bland spindle cells in a plexiform pattern, a mucinous extracellular matrix and a network of thin blood vessels. These findings are completely in line with the two previous reported cases. There was a strong positivity for α-smooth muscle actin and a low proliferation index (<2%). The tumour had no C-KIT or CD34 expression and no mutation in the C-KIT and PDFGRα genes. Plexiform angiomyxoid myofibroblastic tumour may present a new mesenchymal tumour entity in the stomach.
Human herpes virus 6 in archival cardiac tissues from children with idiopathic dilated cardiomyopathy or congenital heart disease
Authors: Comar M , D’Agaro P , Campello C , Poli A , Breinholt J P , Towbin J A , Vatta M
Published: September 2008

Objective:

To explore the possible role of human herpes virus 6 (HHV-6) in cardiac disorders in childhood in a retrospective study on archival specimens of explanted hearts.

Methods:

16 children (median age at transplantation 11.0 years) with idiopathic dilated cardiomyopathy (DCM) and 19 children (median age at transplantation 1.0 year) with congenital heart disease (CHD), previously found to be negative for other cardiotropic viruses such as enteroviruses, adenovirus, parvovirus B19, cytomegalovirus and Epstein–Barr virus, were tested for HHV-6 by quantitative real-time PCR and by genotyping. In addition, HHV-7/8 infection was investigated by qualitative PCR.

Results:

HHV-6 B variant was detected in 11 of 35 samples (31.4%) with a mean viral load of 3.1×102 copies/μg of DNA. When assessed by heart disorder, the prevalence was different in the two groups (43.7% in DCM and 21% in CHD) while the mean viral loads were similar. In a logistic multivariate analysis HHV-6 was independently associated with DCM, taking CHD as reference and adjusting for age (best estimate: OR = 6.94; 95% CI 1.00 to 49.85; p = 0.05).

Conclusions:

Although the clinical significance of the results is unknown, HHV-6 B genome is frequently detected in explanted hearts from children with DCM and to a lesser extent with CHD, thus adding evidence for HHV-6 cardiac involvement.
Polymorphous low-grade adenocarcinoma of the nasopharynx: a case report and brief review
Authors: Wei Y-C , Huang C-C , Chien C-Y , Hwang J-C , Chen W-J
Published: September 2008

Polymorphous low-grade adenocarcinoma (PLGA) is a rare tumour that mostly affects oral minor salivary glands. Our review of the literature found that there are only two reported cases of PLGA originating in the nasopharynx. Another nasopharyngeal PLGA in a 14-year-old boy is reported, focusing on the histopathological features and ultrastructural findings.
Malignant perivascular epithelioid cell tumour of the fibula: a report and a short review of bone perivascular epithelioid cell tumour
Authors: Lian D W Q , Chuah K L , Cheng M H W , Yap W M
Published: September 2008

Perivascular epithelioid cell tumour (PEComa) is a term applied to a family of mesenchymal tumours composed of varying proportions of spindle and epithelioid cell components associated with HMB-45 expression. PEComa rarely arises in the soft tissue, visceral organs, skin and bone. This report details an instance when a purely epithelioid PEComa arose from the right fibula of a 52-year-old Chinese woman without features of tuberous sclerosis complex. The excision specimen disclosed an epithelioid tumour with a nested pattern associated with areas of nuclear pleomorphism, mitotic activity, necrosis and vascular invasion in addition to HMB-45 expression on immunohistochemistry. To the best of the authors’ knowledge, this represents the first case of a histologically malignant PEComa of the bone. A short review of primary bone PEComas and potential problems in diagnosis is presented.
A case ofErysipelothrix rhusiopathiaecausing bilateral endogenous endophthalmitis
Authors: Elvy J , Hanspal I , Simcock P
Published: September 2008

This report describes a case of bilateral endogenous endophthalmitis caused byErysipelothrix rhusiopathiae, an occupational zoonotic pathogen, which was successfully treated with intravenous penicillin G followed by oral linezolid. This is believed to be the first report ofE rhusiopathiaecausing endogenous endophthalmitis.
Calathea ecuadoriana and C. contrafenestra, new Ecuadorian species in Calathea series Comosae (Marantaceae)
Authors: Kennedy Haelen
Published: September 2008

Two Ecuadorian species belonging to Calathea series Comosae (Petersen) Schumann are described as new. Their inflorescences are characterized by the presence of both fertile and sterile bracts. The fertile and sterile bracts are similar morphologically in C. ecuadoriana but strongly dimorphic in C. contrafenestra. Differences in floral morphology and chromosome number which correlate with bract morphology indicate Calathea series Comosae as currently defined is probably diphyletic.
Effect of white clover mosaic virus infection on various processes relevant to symbiotic N2 fixation in red clover
Authors: Khadhair A. H. , Sinha R. C. , Peterson J. F.
Published: September 2008

The effect of white clover mosaic virus infection on several factors relevant to symbiotic N2 fixation was determined in nodulated red clover (Trifolium pratense L.) plants at 10-leaf, preblooming, blooming, and flower-senescence stages of growth, corresponding to 3, 6, 9, and 12 weeks after virus inoculation, respectively. Virus infection caused a significant [Formula: see text] reduction of plant growth (top and root weight), nodulation (number and weight of nodules), rhizobial population, nitrogenase activity, and leghemoglobin concentration in the nodules. The presence of a high concentration of virus within nodules at all harvest times was indicated by infectivity assays. The leghemoglobin was shown to be localized in the peribacteroidal space by a cytochemical technique. A significant increase in inducible nitrate reductase activity was associated with virus infection of plants.
Growth and development at cold-hardening temperatures. Chlorophyll–protein complexes and thylakoid membrane polypeptides
Authors: Elfman B. , Huner N. P. A. , Griffith M. , Krol M. , Hopkins W. G. , Hayden D. B.
Published: September 2008

Chlorophyll–protein complexes of thylakoid membranes from rye plants (Secale cereale L. cv. Puma) grown at warm and cold-hardening temperatures were investigated by gel electrophoresis. Complex IV from cold-grown tissue was detectable in the presence of dodecyl sulfate if and only if solubilization and electrophoresis were performed at 4 °C, whereas complex IV from warm-grown material was detectable if membrane solubilization and electrophoresis were performed at either 4 or 23 °C in the presence of dodecyl sulfate. In the presence of octyl-β-D-glucopyranoside, the chlorophyll–protein complexes from cold-grown tissue were less stable at 23 °C than those from warm-grown tissue. Regardless of the detergent used, there was always more oligomer of the light-harvesting complex present in samples prepared from thylakoid membranes of warm-grown tissue than those from membranes of cold-grown tissue. It is concluded that the pigment–protein interaction in those complexes associated with photosystem II and the light-harvesting chlorophyll a/b – protein complex has been altered upon growth and development at cold-hardening temperatures.
Asparagine synthetase in Zea mays
Authors: Oaks Ann , Ross D. W.
Published: September 2008

Properties of asparagine synthetase from various tissues of Zea mays L. (embryo and endosperm from developing seeds; scutella and roots from young seedlings) and from cotyledons of Glycine max L. have been compared. The specific activities obtained with extracts from soybean cotyledons were 10–30-fold higher than activities obtained from any of the maize tissues. The apparent Km values (millimolar) were about 0.5 for glutamine and about 2.0 for [Formula: see text] for the enzymes from the various corn tissues and 0.18 and 3.0, respectively, for soybean cotyledons. The Vmax values were about twofold higher for glutamine compared with [Formula: see text] for corn embryos, endosperms, and scutella and for soybean cotyledons. With corn roots, on the other hand, a slightly higher Vmax was obtained when [Formula: see text] was the nitrogen donor. With the exception of corn root enzyme, glutamine protected asparagine synthetase from heat inactivation. [Formula: see text] had no protective effect on the enzyme from any of the tissues examined. The results indicate that the enzyme from corn (any tissue) is not as stringent in its requirement for glutamine as is the enzyme from soybean cotyledons and that the root enzyme responds to [Formula: see text] and glutamine in a unique fashion. The enzyme obtained from developing seeds (embryo or endosperm) was inhibited by asparagine. All the corn enzymes were inhibited by ADP to a greater extent than by AMP or ATP. Enzyme from the scutella or soybean cotyledons but not from the root or the developing embryo was inhibited by the glutamine analogue albizziin. Thus there appear to be important differences in the properties of asparagine synthetases extracted from various tissues of corn and soybean cotyledons.