bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of host and environmental factors in the epidemiology of rumpwear in brushtail possums
Authors: Hufschmid J. , Handasyde K. A. , Beveridge I.
Published: November 2010

Rumpwear is a common, but poorly defined and understood disease of brushtail possums (Trichosurus spp.) in Australia and New Zealand, resulting in varying degrees of fur loss. Populations of Trichosurus cunninghami (mountain brushtail possum) and T. vulpecula (common brushtail possum) were studied over two years at Boho South (Victoria), to describe the disease, investigate its prevalence and explore its epidemiology. The main type of lesion observed was coat damage in the lumbo-sacral region, and increased severity of rumpwear was related to decreased coat length and increased hair breakage. Significant skin lesions were rare and hair breakage patterns suggested mechanical damage. Rumpwear was very prevalent in both T. cunninghami and T. vulpecula, but very severe rumpwear was rare. There was no true seasonal pattern to the prevalence of rumpwear in T. cunninghami and sex and habitat did not affect prevalence or severity. Prevalence and severity of rumpwear did, however, increase with age. There were no significant relationships between the number of previous captures or body condition index with rumpwear.
Discovery of a host fish for glochidia of Velesunio angasi (Sowerby, 1867) (Bivalvia:Unionoida:Hyriidae) from the Fortescue River, Pilbara, Western Australia
Authors: Klunzinger Michael W. , Morgan David L. , Lymbery Alan J. , Ebner Brendan C. , Beatty Stephen J. , Thomson Gordon L.
Published: November 2010

Freshwater fishes are the most common hosts of the glochidia (parasitic larvae) of freshwater mussels (Bivalvia: Unionoida: Unionoidea). Velesunio angasi (Sowerby, 1867) (Hyriidae), is the only known hyriid species recorded from the Fortescue River in the Pilbara region of Western Australia. Eleven species of fish (n = 516) were captured from pools of the Fortescue River in June 2010. Small, white, bladder-like cysts were observed on Neosilurus hyrtlii Steindachner, 1867, though not on any of the remaining 10 species examined. Light microscopy of sectioned cysts revealed that they contained glochidia that were of similar size and shape to those of V. angasi. Glochidia were found on 73.2% of 168 N. hyrtlii examined, with a mean intensity of 3.3 cysts per infested fish. Prevalence was significantly greater on smaller fish (P < 0.01); however, no relationship between size and intensity of infestation was observed. This represents the first record of glochidia infestation on fish from the Pilbara region.
Sequence-specific assembly of FtsK hexamers establishes directional translocation on DNA
Authors: Graham James E. , Sherratt David J. , Szczelkun Mark D.
Published: November 2010

FtsK is a homohexameric, RecA-like dsDNA translocase that plays a key role in bacterial chromosome segregation. The FtsK regulatory γ-subdomain determines directionality of translocation through its interaction with specific 8 base pair chromosomal sequences [(KOPS); FtsK Orienting / Polarizing Sequence(s)] that are cooriented with the direction of replication in the chromosome. We use millisecond-resolution ensemble translocation and ATPase assays to analyze the assembly, initiation, and translocation of FtsK. We show that KOPS are used to initiate new translocation events rather than reorient existing ones. By determining kinetic parameters, we show sigmoidal dependences of translocation and ATPase rates on ATP concentration that indicate sequential cooperative coupling of ATP hydrolysis to DNA motion. We also estimate the ATP coupling efficiency of translocation to be 1.63–2.11 bp of dsDNA translocated/ATP hydrolyzed. The data were used to derive a model for the assembly, initiation, and translocation of FtsK hexamers.
Mechanisms of protein oligomerization, the critical role of insertions and deletions in maintaining different oligomeric states
Authors: Hashimoto Kosuke , Panchenko Anna R.
Published: November 2010

The main principles of protein-protein recognition are elucidated by the studies of homooligomers which in turn mediate and regulate gene expression, activity of enzymes, ion channels, receptors, and cell-cell adhesion processes. Here we explore oligomeric states of homologous proteins in various organisms to better understand the functional roles and evolutionary mechanisms of homooligomerization. We observe a great diversity in mechanisms controlling oligomerization and focus in our study on insertions and deletions in homologous proteins and how they enable or disable complex formation. We show that insertions and deletions which differentiate monomers and dimers have a significant tendency to be located on the interaction interfaces and about a quarter of all proteins studied and forty percent of enzymes have regions which mediate or disrupt the formation of oligomers. We suggest that relatively small insertions or deletions may have a profound effect on complex stability and/or specificity. Indeed removal of complex enabling regions from protein structures in many cases resulted in the complete or partial loss of stability. Moreover, we find that insertions and deletions modulating oligomerization have a lower aggregation propensity and contain a larger fraction of polar, charged residues, glycine and proline compared to conventional interfaces and protein surface. Most likely, these regions may mediate specific interactions, prevent nonspecific dysfunctional aggregation and preclude undesired interactions between close paralogs therefore separating their functional pathways. Last, we show how the presence or absence of insertions and deletions on interfaces might be of practical value in annotating protein oligomeric states.
pH-(low)-insertion-peptide (pHLIP) translocation of membrane impermeable phalloidin toxin inhibits cancer cell proliferation
Authors: An Ming , Wijesinghe Dayanjali , Andreev Oleg A. , Reshetnyak Yana K. , Engelman Donald M.
Published: November 2010

We find that pH-(low)-insertion-peptide (pHLIP)-facilitated translocation of phalloidin, a cell-impermeable polar toxin, inhibits the proliferation of cancer cells in a pH-dependent fashion. The monomeric pHLIP inserts its C terminus across a membrane under slightly acidic conditions (pH 6–6.5), forming a transmembrane helix. The delivery construct carries phalloidin linked to its inserting C terminus via a disulfide bond that is cleaved inside cells, releasing the toxin. To facilitate delivery of the polar agent, a lipophilic rhodamine moiety is also attached to the inserting end of pHLIP. After a 3 h incubation at pH 6.1–6.2 with 2–4 
μ
M concentrations of the construct, proliferation in cultures of HeLa, JC, and M4A4 cancer cells is severely disrupted (> 90% inhibition of cell growth). Treated cells also show signs of cytoskeletal immobilization and multinucleation, consistent with the expected binding of phalloidin to F actin, stabilizing the filaments against depolymerization. The antiproliferative effect was not observed without the hydrophobic facilitator (rhodamine). The biologically active delivery construct inserts into 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine lipid bilayers with an apparent pK
a
of ∼6.15, similar to that of the parent pHLIP peptide. Sedimentation velocity experiments show that the delivery construct is predominantly monomeric (> 90%) in solution under the conditions employed to treat cells (pH 6.2, 4 μM). These results provide a lead for antitumor agents that would selectively destroy cells in acidic tumors. Such a targeted approach may reduce both the doses needed for cancer chemotherapy and the side effects in tissues with a normal pH.
Characterizing the regularity of tetrahedral packing motifs in protein tertiary structure
Authors: Day Ryan , Lennox Kristin P. , Dahl David B. , Vannucci Marina , Tsai Jerry W.
Published: November 2010

Motivation: While protein secondary structure is well understood, representing the repetitive nature of tertiary packing in proteins remains difficult. We have developed a construct called the relative packing group (RPG) that applies the clique concept from graph theory as a natural basis for defining the packing motifs in proteins. An RPG is defined as a clique of residues, where every member contacts all others as determined by the Delaunay tessellation. Geometrically similar RPGs define a regular element of tertiary structure or tertiary motif (TerMo). This intuitive construct provides a simple approach to characterize general repetitive elements of tertiary structure.

Results: A dataset of over 4 million tetrahedral RPGs was clustered using different criteria to characterize the various aspects of regular tertiary structure in TerMos. Grouping this data within the SCOP classification levels of Family, Superfamily, Fold, Class and PDB showed that similar packing is shared across different folds. Classification of RPGs based on residue sequence locality reveals topological preferences according to protein sizes and secondary structure. We find that larger proteins favor RPGs with three local residues packed against a non-local residue. Classifying by secondary structure, helices prefer mostly local residues, sheets favor at least two local residues, while turns and coil populate with more local residues. To depict these TerMos, we have developed 2 complementary and intuitive representations: (i) Dirichlet process mixture density estimation of the torsion angle distributions and (ii) kernel density estimation of the Cartesian coordinate distribution. The TerMo library and representations software are available upon request.

Contact:  jtsai@pacific.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
A new level of complexity in the male alliance networks of Indian Ocean bottlenose dolphins (
Tursiops
sp.)
Authors: Connor Richard C. , Watson-Capps Jana J. , Sherwin William B. , Krützen Michael
Published: November 2010

Male bottlenose dolphins in Shark Bay, Western Australia form two levels of alliances; two to three males cooperate to herd individual females and teams of greater than three males compete with other groups for females. Previous observation suggested two alliance tactics: small four to six member teams of relatives that formed stable pairs or trios and unrelated males in a large 14-member second-order alliance that had labile trio formation. Here, we present evidence for a third level of alliance formation, a continuum of second-order alliance sizes and no relationship between first-order alliance stability and second-order alliance size. These findings challenge the ‘two alliance tactics’ hypothesis and add to the evidence that Shark Bay male bottlenose dolphins engage in alliance formation that likely places considerable demands on their social cognition.
Digit ratios predict polygyny in early apes,
Ardipithecus
, Neanderthals and early modern humans but not in
Australopithecus
Authors: Nelson Emma , Rolian Campbell , Cashmore Lisa , Shultz Susanne
Published: November 2010

Social behaviour of fossil hominoid species is notoriously difficult to predict owing to difficulties in estimating body size dimorphism from fragmentary remains and, in hominins, low canine size dimorphism. Recent studies have shown that the second-to-fourth digit ratio (2D : 4D), a putative biomarker for prenatal androgen effects (PAEs), covaries with intra-sexual competition and social systems across haplorrhines; non-pair-bonded polygynous taxa have significantly lower 2D : 4D ratios (high PAE) than pair-bonded monogamous species. Here, we use proximal phalanx ratios of extant and fossil specimens to reconstruct the social systems of extinct hominoids.
Pierolapithecus catalaunicus
,
Hispanopithecus laietanus
and
Ardipithecus ramidus
have ratios consistent with polygynous extant species, whereas the ratio of
Australopithecus afarensis
is consistent with monogamous extant species. The early anatomically modern human Qafzeh 9 and Neanderthals have lower digit ratios than most contemporary human populations, indicating increased androgenization and possibly higher incidence of polygyny. Although speculative owing to small sample sizes, these results suggest that digit ratios represent a supplementary approach for elucidating the social systems of fossil hominins.
Subretinal electronic chips allow blind patients to read letters and combine them to words
Authors: Zrenner Eberhart , Bartz-Schmidt Karl Ulrich , Benav Heval , Besch Dorothea , Bruckmann Anna , Gabel Veit-Peter , Gekeler Florian , Greppmaier Udo , Harscher Alex , Kibbel Steffen , Koch Johannes , Kusnyerik Akos , Peters Tobias , Stingl Katarina , Sachs Helmut , Stett Alfred , Szurman Peter , Wilhelm Barbara , Wilke Robert
Published: November 2010

A light-sensitive, externally powered microchip was surgically implanted subretinally near the macular region of volunteers blind from hereditary retinal dystrophy. The implant contains an array of 1500 active microphotodiodes (‘chip’), each with its own amplifier and local stimulation electrode. At the implant's tip, another array of 16 wire-connected electrodes allows light-independent direct stimulation and testing of the neuron–electrode interface. Visual scenes are projected naturally through the eye's lens onto the chip under the transparent retina. The chip generates a corresponding pattern of 38 × 40 pixels, each releasing light-intensity-dependent electric stimulation pulses. Subsequently, three previously blind persons could locate bright objects on a dark table, two of whom could discern grating patterns. One of these patients was able to correctly describe and name objects like a fork or knife on a table, geometric patterns, different kinds of fruit and discern shades of grey with only 15 per cent contrast. Without a training period, the regained visual functions enabled him to localize and approach persons in a room freely and to read large letters as complete words after several years of blindness. These results demonstrate for the first time that subretinal micro-electrode arrays with 1500 photodiodes can create detailed meaningful visual perception in previously blind individuals.
Workers influence royal reproduction
Authors: Gill Richard J. , Hammond Robert L.
Published: November 2010

Understanding which parties regulate reproduction is fundamental to understanding conflict resolution in animal societies. In social insects, workers can influence male production and sex ratio. Surprisingly, few studies have investigated worker influence over which queen(s) reproduce(s) in multiple queen (MQ) colonies (skew), despite skew determining worker-brood relatedness and so worker fitness. We provide evidence for worker influence over skew in a functionally monogynous population of the antLeptothorax acervorum. Observations of MQ colonies leading up to egg laying showed worker aggressive and non-aggressive behaviour towards queens and predicted which queen monopolized reproduction. In contrast, among-queen interactions were rare and did not predict queen reproduction. Furthermore, parentage analysis showed workers favoured their mother when present, ensuring closely related fullsibs (averager= 0.5) were reared instead of less related offspring of other resident queens (r≤ 0.375). Discrimination among queens using relatedness-based cues, however, seems unlikely as workers also biased their behaviour in colonies without a mother queen. In other polygynous populations of this species, workers are not aggressive towards queens and MQs reproduce, showing the outcome of social conflicts varies within species. In conclusion, this study supports non-reproductive parties having the power and information to influence skew within cooperative breeding groups.
Measuring social networks in British primary schools through scientific engagement
Authors: Conlan A. J. K. , Eames K. T. D. , Gage J. A. , von Kirchbach J. C. , Ross J. V. , Saenz R. A. , Gog J. R.
Published: November 2010

Primary schools constitute a key risk group for the transmission of infectious diseases, concentrating great numbers of immunologically naive individuals at high densities. Despite this, very little is known about the social patterns of mixing within a school, which are likely to contribute to disease transmission. In this study, we present a novel approach where scientific engagement was used as a tool to access school populations and measure social networks between young (4–11 years) children. By embedding our research project within enrichment activities to older secondary school (13–15) children, we could exploit the existing links between schools to achieve a high response rate for our study population (around 90% in most schools). Social contacts of primary school children were measured through self-reporting based on a questionnaire design, and analysed using the techniques of social network analysis. We find evidence of marked social structure and gender assortativity within and between classrooms in the same school. These patterns have been previously reported in smaller studies, but to our knowledge no study has attempted to exhaustively sample entire school populations. Our innovative approach facilitates access to a vitally important (but difficult to sample) epidemiological sub-group. It provides a model whereby scientific communication can be used to enhance, rather than merely complement, the outcomes of research.
Development, validation and field application of an RNA‐based growth index in juvenile plaice Pleuronectes platessa
Authors: Ciotti B. J. , Targett T. E. , Nash R. D. M. , Batty R. S. , Burrows M. T. , Geffen A. J.
Published: November 2010

A general mechanism relating RNA concentration and growth rate is derived from four physiological assumptions and developed into a growth index for juvenile plaice Pleuronectes platessa. The index describing instantaneous growth rates (G, day−1) in the laboratory with the lowest Akaike information criterion with small‐sample bias adjustment was a function of RNA concentration (R, ), temperature (T, ° K), body mass (M, g) and DNA concentration (D, ): G = β0 + βRR + βTT + βT2T2 + βMM + βDD + βRTRT. RNA concentration began to respond to changes in feeding conditions within 8 days, suggesting that the index reflects growth rate in the short‐term. Furthermore, the index distinguished between rapid growth and negative growth of juvenile P. platessa measured directly in laboratory and field enclosures, respectively. An application of the RNA‐based growth index at two beaches on the west coast of Scotland suggested that the growth of juvenile P. platessa varies considerably in space and time and is submaximum in late summer.
Diversity in destinations, routes and timing of small adult and sub‐adult striped bass Morone saxatilis on their southward autumn migration
Authors: Mather M. E. , Finn J. T. , Pautzke S. M. , Fox D. , Savoy T. , Brundage H. M. , Deegan L. A. , Muth R. M.
Published: November 2010

Almost three‐quarters of the 46 young adult and sub‐adult striped bass Morone saxatilis that were acoustically tagged in Plum Island Estuary, Massachusetts, U.S.A., in the summer of 2006 were detected in one or more southern coastal arrays during their autumn migration. On the basis of the trajectories along which these M. saxatilis moved from feeding to overwintering areas, three migratory groups emerged. After leaving Plum Island Estuary, about half of the fish were detected only in a mid‐latitude array, Long Island Sound. The other half of the tagged fish were detected during autumn and winter in a more southern array, the Delaware Estuary. This latter group of fish may have used two routes. Some travelled to the Delaware Estuary through Long Island Sound while other fish may have taken a second, more direct, coastal route that did not include Long Island Sound. Consequently, a seemingly homogeneous group of fish tagged at the same time in the same non‐natal feeding location exhibited a diversity of southward movement patterns that could affect population‐level processes. These three groups that differed in overwintering location and migration route could be movement contingents with migratory connectivity.
Brown trout Salmo trutta redd superimposition by spawning Lampetra species in a lowland stream
Authors: Nika N. , Virbickas T.
Published: November 2010

Reproductive interaction between sympatric lampreys and salmonids was studied. The superimposition of brown trout Salmo trutta redds by spring‐spawning river lamprey Lampetra fluviatilis and brook lamprey Lampetra planeri was examined in a small lowland stream of western Lithuania. A high superimposition rate of S. trutta redds by both L. fluviatilis (up to 83%) and L. planeri (up to 48%) was found, when the spawning intensity of Lampetra spp. was high. The occurrence of this phenomenon is the result of the overlap in the spawning habitat preferences at the reach‐scale and at the microhabitat scale for the three species. One of the main requirements for Lampetra spp. spawning site selection was the negative streambed slope, an essential trait of the pool–riffle transitional zone. The structure of the salmonid redd created a considerable negative microhabitat slope suitable for Lampetra spp. spawning, which put the redds under a higher susceptibility to be superimposed. The timing of Lampetra spp. spawning overlapped closely with the emergence of S. trutta fry, suggesting a probable ecological effect of superimposition on S. trutta in the pre‐emergent and emerging stages.
The heterozygous abp1/ABP1 insertional mutant has defects in functions requiring polar auxin transport and in regulation of early auxin‐regulated genes
Authors: Effendi Yunus , Rietz Steffen , Fischer Urs , Scherer Günther F. E.
Published: November 2010

AUXIN‐BINDING PROTEIN 1 (ABP1) is not easily accessible for molecular studies because the homozygous T‐DNA insertion mutant is embryo‐lethal. We found that the heterozygous abp1/ABP1 insertion mutant has defects in auxin physiology‐related responses: higher root slanting angles, longer hypocotyls, agravitropic roots and hypocotyls, aphototropic hypocotyls, and decreased apical dominance. Heterozygous plants flowered earlier than wild‐type plants under short‐day conditions. The length of the main root, the lateral root density and the hypocotyl length were little altered in the mutant in response to auxin. Compared to wild‐type plants, transcription of early auxin‐regulated genes (IAA2, IAA11, IAA13, IAA14, IAA19, IAA20, SAUR9, SAUR15, SAUR23, GH3.5 and ABP1) was less strongly up‐regulated in the mutant by 0.1, 1 and 10 μm IAA. Surprisingly, ABP1 was itself an early auxin‐up‐regulated gene. IAA uptake into the mutant seedlings during auxin treatments was indistinguishable from wild‐type. Basipetal auxin transport in young roots was slower in the mutant, indicating a PIN2/EIR1 defect, while acropetal transport was indistinguishable from wild‐type. In the eir1 background, three of the early auxin‐regulated genes tested (IAA2, IAA13 and ABP1) were more strongly induced by 1 μm IAA in comparison to wild‐type, but eight of them were less up‐regulated in comparison to wild‐type. Similar but not identical disturbances in regulation of early auxin‐regulated genes indicate tight functional linkage of ABP1 and auxin transport regulation. We hypothesize that ABP1 is involved in the regulation of polar auxin transport, and thus affects local auxin concentration and early auxin gene regulation. In turn, ABP1 itself is under the transcriptional control of auxin.
Differential response to salinity and water deficit stress in Polypogon monspeliensis (L.) Desf. provenances during germination
Authors: Atia A. , Smaoui A. , Barhoumi Z. , Abdelly C. , Debez A.
Published: November 2010

The effects of provenance, salinity (0, 100, 200, 300 and 400 mm NaCl) and water deficit (0, −0.6, −1.1, −1.6 and −2.1 MPa mannitol solutions) on germination success of Polypogon monspeliensis were investigated. Eight Tunisian provenances from different bioclimatic origins were considered. Seed mass varied significantly between populations. Germination percentage was significantly affected by provenance, salinity and their interaction. Even at 300 mm NaCl, germination percentage of Tabarka, Kelbia and Kebili ranged from ca. 60% to ca. 85%, whereas Monastir, Gabes and El Haouaria succeeded in germinating in 200 mm NaCl. The 300 mm NaCl treatment highly reduced germination of Monastir and El Haouaria, and inhibited that of Gabes. Soliman and El Jem were the least salt‐tolerant provenances. The severity of water deficit impact on seed germination was also provenance‐dependent, especially at osmotic potentials of −1.1 to −1.6 MPa. At −1.6 MPa, germination percentage of Tabarka, Monastir and Kebili was close to 80%, while that of Gabes, El Jem and Kelbia was 0%, 5% and 20%, respectively. Regardless of provenance, germination was strongly impaired at −2.1 MPa. The variability of stress tolerance in P. monspeliensis could be of practical significance in programmes aimed at restoring arid and salt‐affected lands since it allows use of provenances that germinate and establish successfully under unfavourable conditions prevailing in such zones.
The language of nitric oxide signalling
Authors: Baudouin E.
Published: November 2010

Nitric oxide (NO) has recently joined the select circle of the ubiquitous molecules of plant signalling networks. Indeed, the last decade has produced a tremendous amount of data that evidence the diversity of physiological situations in which NO is involved in plants and the complexity of NO biology. These data also underline our difficulties in providing simple answers to the cardinal questions of where NO comes from and how the NO message is converted into a physiological response. The identification of NO primary targets and NO‐regulated genes provides new opportunities to connect NO biochemistry and NO biology. This review summarises our current understanding of NO signalling, from the generation of the NO message to its execution into a cellular response. The review particularly considers whether and how NO may be responsible for specific signalling in different physiological processes.
Expression analyses of AtAGP17 and AtAGP19, two lysine‐rich arabinogalactan proteins, in Arabidopsis
Authors: Yang J. , Zhang Y. , Liang Y. , Showalter A. M.
Published: November 2010

AtAGP17 and AtAGP19 are members of the lysine‐rich arabinogalactan protein (AGP) subfamily in Arabidopsis. Detailed anatomical analysis of promoter activity of the AtAGP19 gene was carried out using transgenic Arabidopsis plants expressing a PAtAGP19:GUS fusion. AtAGP19 promoter activity was tissue‐specific and associated with vascular bundles, particularly differentiating xylem elements. Peptide‐specific antibodies were raised against the Lys‐rich regions of AtAGP17 and AtAGP19 and used to study the organ‐specific expression patterns of these two AGPs. AtAGP17 and AtAGP19 were most abundant in roots and flowers, moderately abundant in stems, seedlings and siliques and virtually absent in leaves. Antibodies specific for AtAGP17 and AtAGP19, as reported here, represent valuable tools for understanding the biology of these two AGPs.
The Orientational Consequences of Flocking Behaviour in Homing Pigeons, Columba livia
Authors: Perera Theresa Burt de , Guilford Tim
Published: November 2010

Two experiments are described which investigate the orientational consequences of flocking in homing pigeons Columba livia. Previous experiments have shown that homing pigeons placed inside a clear‐sided release box for 5 min before release from a familiar site have enhanced ground homing speed compared with those placed in an opaque‐sided box. It is assumed that previewing the surrounding landscape allows for faster homing since a bird denied this information must accumulate the knowledge on release. In experiment 1, using the same technique developed in these experiments but releasing the birds in pairs we showed that within familiar areas, homing pigeons can exploit a partner that has acquired more information, allowing them to home more quickly. In experiment 2 we attempted to test three potential strategies which may occur during homing flights. The results do not conclusively distinguish between these three mechanisms but suggest that orientation of the pairs of birds is most likely to have resulted from a compromise of individual tendencies, or from following the best homer, but not from following a ‘governing leader’. The consequence of these mechanisms is discussed.
Talorchestia tricornuta Shoemaker (Amphipoda, Talitridae) from Sandy Shores of Gabon: Compass Mechanisms of Orientation
Authors: Ugolini Alberto , Vignali Barbara , Posso Paul
Published: November 2010

We studied the capacity for zonal recovery in an equatorial sandhopper, Talorchestia tricornuta, inhabiting the sandy beaches of equatorial West Africa. These beaches are often narrow and backed by an evident landscape. The sky usually has heavy cloud cover. The experiments were performed both in a confined environment and in the field, in full sun or an overcast sky, with the magnetic field natural, deviated or absent T. tricornuta was able to assume the correct direction using the sun and magnetic field as orienting factors. Moreover, the releases in the field with the natural landscape visible indicate that the landscape may constitute a further important orienting factor in zonal recovery.
American Power: Crisis or Renewal?
Authors: Dumbrell John
Published: November 2010

Perceptions of American international decline are not new. This article considers the current debate over US decline in historical context, noting that current forecasts of decline are less apocalyptic than those of the later Cold War period. The foreign policy legacy of George W. Bush is assessed. Perceptions of domestic US political paralysis are discussed, along with the need for the Obama administration to move clearly in the direction of global retrenchment.
The View of Old and New Powers on the Legitimacy of International Institutions
Authors: Zürn Michael , Stephen Matthew
Published: November 2010

International institutions have developed into a site of political authority of their own as can be seen by looking at a number of authority indicators. The concept of international authority, however, is intimately bound to the concept of legitimacy. The stronger the role that international institutions play in policymaking, the stronger the demands for their legitimacy that can be expected to arise. Against this background, we ask which of the state powers analysed in this special issue prefer which form of legitimation of international institutions, whether their general conceptions of legitimacy diverge or converge, and what this means for the future of global governance.
Brazil's Rising Ambition in a Shifting Global Balance of Power
Authors: Sotero Paulo
Published: November 2010

Rooted in democracy and economic stability and propelled by President Lula's extraordinary popularity and assertive foreign policy, Brazil's recent rise has allowed the country to gain a new global pre-eminence despite its failure to achieve the stated goals of its international strategy. Consolidation of the nation's place and influence will depend as much on its ability to tackle domestic vulnerabilities, such as low competitiveness and low savings and investment rates that limit potential economic growth, as on its capacity to calibrate ambition to its position in the redistribution of international power under way in the early twenty-first century.
Variations on a theme: parents and teachers talking
Authors: LALUVEIN JACKIE
Published: November 2010

This article draws upon the findings from a unique research project that provided new insights into the relationship between parents and teachers working with children experiencing difficulties in school. The article introduces ten modes of parents and teachers ‘working together’, each of which has implications for the provision for children experiencing difficulties in school, as well as their parents and teachers.
Regulation of Oligodendrocyte Differentiation and Myelination
Authors: Emery Ben
Published: November 2010

Despite the importance of myelin for the rapid conduction of action potentials, the molecular bases of oligodendrocyte differentiation and central nervous system (CNS) myelination are still incompletely understood. Recent results have greatly advanced this understanding, identifying new transcriptional regulators of myelin gene expression, elucidating vital roles for microRNAs in controlling myelination, and clarifying the extracellular signaling mechanisms that orchestrate the development of myelin. Studies have also demonstrated an unexpected level of plasticity of myelin in the adult CNS. These recent advances provide new insight into how remyelination may be stimulated in demyelinating disorders such as multiple sclerosis.
Specification and Morphogenesis of Astrocytes
Authors: Freeman Marc R.
Published: November 2010

Astrocytes are the most abundant cell type in the mammalian brain. Interest in astrocyte function has increased dramatically in recent years because of their newly discovered roles in synapse formation, maturation, efficacy, and plasticity. However, our understanding of astrocyte development has lagged behind that of other brain cell types. We do not know the molecular mechanism by which astrocytes are specified, how they grow to assume their complex morphologies, and how they interact with and sculpt developing neuronal circuits. Recent work has provided a basic understanding of how intrinsic and extrinsic mechanisms govern the production of astrocytes from precursor cells and the generation of astrocyte diversity. Moreover, new studies of astrocyte morphology have revealed that mature astrocytes are extraordinarily complex, interact with many thousands of synapses, and tile with other astrocytes to occupy unique spatial domains in the brain. A major challenge for the field is to understand how astrocytes talk to each other, and to neurons, during development to establish appropriate astrocytic and neuronal network architectures.
Changing Face of Microglia
Authors: Graeber Manuel B.
Published: November 2010

Microglia are resident brain cells that sense pathological tissue alterations. They can develop into brain macrophages and perform immunological functions. However, expression of immune proteins by microglia is not synonymous with inflammation, because these molecules can have central nervous system (CNS)–specific roles. Through their involvement in pain mechanisms, microglia also respond to external threats. Experimental studies support the idea that microglia have a role in the maintenance of synaptic integrity. Analogous to electricians, they are capable of removing defunct axon terminals, thereby helping neuronal connections to stay intact. Microglia in healthy CNS tissue do not qualify as macrophages, and their specific functions are beginning to be explored.
Large-Area Three-Dimensional Molecular Ordering of a Polymer Brush by One-Step Processing
Authors: Hosono Nobuhiko , Kajitani Takashi , Fukushima Takanori , Ito Kazuki , Sasaki Sono , Takata Masaki , Aida Takuzo
Published: November 2010

Bend It, Stretch It

Materials (such as those found in some artificial muscle systems) that are used for stimulus-controlled bending or stretching, require long-range ordering so that local chemical triggers will result in long-range bending or flexing motions.

Hosono
et al.

(p.
808
) observed that a sandwich of a polymethacrylate between uniaxially stretched Teflon sheets develops three-dimensional ordering. Upon hot pressing, the main chains of the polymer brushes aligned homeotropically to the film plane, whereas the side chains, containing azobenzene groups, oriented horizontally along the drawing direction of the Teflon sheets. With some azobenzene groups, alternate irradiation with ultraviolet and visible light made the composites bend and stretch reversibly.
Open mHealth Architecture: An Engine for Health Care Innovation
Authors: Estrin Deborah , Sim Ida
Published: November 2010

Standardized interfaces and shared components are critical for realizing the potential of mobile-device–enabled health care delivery and research.
Seeing Through Incapacities

The Mind's Eye
by Oliver Sacks

Knopf, New York, 2010. 281 pp. $26.95. ISBN 9780307272089.
Authors: Koch Christof
Published: November 2010

In his latest collection of brain-gone-wrong stories, Sacks also recounts his experiences dealing with his own ocular melanoma.
Increased Atmospheric CO
2
During the Middle Eocene
Authors: Pearson Paul N.
Published: November 2010

An ocean drill core confirms a dramatic rise in CO
2
levels 40 million years ago, just as the Himalayas grew.
U.N. Biodiversity Summit Yields Welcome and Unexpected Progress
Authors: Normile Dennis
Published: November 2010

At a marathon closing plenary session, the parties to the Convention on Biological Diversity agreed to an ambitious plan to halt the loss of biodiversity, an agreement to combat biopiracy, a scheme to increase conservation funding, and a raft of related policy statements.
Mathematical Modeling of Molecular Data in Translational Medicine: Theoretical Considerations
Authors: Marko Nicholas F. , Weil Robert J.
Published: November 2010

Appropriate data modeling strategies must be used when analyses generate tens of thousands of data points from individual study participants.
Altered Functional Connectivity in Frontal Lobe Circuits Is Associated with Variation in the Autism Risk Gene
CNTNAP2
Authors: Scott-Van Zeeland Ashley A. , Abrahams Brett S. , Alvarez-Retuerto Ana I. , Sonnenblick Lisa I. , Rudie Jeffrey D. , Ghahremani Dara , Mumford Jeanette A. , Poldrack Russell A. , Dapretto Mirella , Geschwind Daniel H. , Bookheimer Susan Y.
Published: November 2010

Children who carry one variant of a brain protein associated with autism exhibit fewer long-range connections between the prefrontal cortex and more posterior brain regions.
Correlation between Serum and Plasma Antibody Titers to Mycobacterial Antigens
Authors: Siev Michael , Yu Xian , Prados-Rosales Rafael , Martiniuk Frank T. , Casadevall Arturo , Achkar Jacqueline M.
Published: November 2010

The ability to utilize serum or plasma samples interchangeably is useful for tuberculosis (TB) serology. We demonstrate a strong correlation between antibody titers to several mycobacterial antigens in serum versus plasma from HIV-infected and non-HIV-infected TB and non-TB patients (
r
= 0.99 to 0.89;
P
< 0.0001). Plasma and serum can be used interchangeably in the same antibody detection assays.
Evaluation of Cobas TaqMan MTB PCR for Detection of
Mycobacterium tuberculosis
Authors: Kim Jeong Hyun , Kim Young Jae , Ki Chang-Seok , Kim Ji-Youn , Lee Nam Yong
Published: November 2010

Nucleic acid-based amplification tests allow the rapid detection of
Mycobacterium tuberculosis
. Recently, a real-time PCR assay for
M. tuberculosis
complex, the Cobas TaqMan MTB test (Roche Diagnostics, Basel, Switzerland), was introduced. We performed a prospective study to evaluate the diagnostic performance of the Cobas TaqMan MTB test system. A total of 406 specimens collected from 247 patients were simultaneously tested by conventional culture, Cobas Amplicor MTB PCR, and TaqMan MTB PCR. The cross-reactivity with other
Mycobacterium
species and the detection limit were also evaluated. Among 406 specimens, a total of 24 specimens (5.9%) were culture positive: 14 specimens were positive by both TaqMan and Amplicor MTB PCRs, while 5 specimens were positive by only TaqMan PCR. The remaining five specimens were negative by both PCR methods. Seven specimens with negative culture results were positive by TaqMan PCR, but five of these were negative by Amplicor MTB PCR. The sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were 79.1%, 98.2%, 73.1%, and 98.7% for TaqMan and 58.3%, 99.5%, 87.5%, and 97.4% for the Amplicor MTB PCR test, respectively. There was no cross-reactivity with
M. tuberculosis
and nontuberculous mycobacterial species. The detection limit for the Cobas TaqMan MTB PCR test was 4.0 copies/μl. The Cobas TaqMan MTB PCR test showed higher sensitivity for detection of the
M. tuberculosis
complex without disturbing the specificity and NPV than the Amplicor MTB PCR test.
Hepatitis B Virus (HBV) Infection and Recombination between HBV Genotypes D and E in Asymptomatic Blood Donors from Khartoum, Sudan
Authors: Mahgoub Shaza , Candotti Daniel , El Ekiaby Magdy , Allain Jean-Pierre
Published: November 2010

Sudan is a highly endemic area for hepatitis B virus (HBV), and >5% of blood donors are chronically infected. To examine potential strategies to improve HBV blood safety, 404 replacement donor samples previously screened for HBV surface antigen (HBsAg) were tested for antibody to HBV core (anti-HBc), anti-surface antigen (anti-HBs), and HBV DNA. Of 145 anti-HBc-containing samples (36%) identified, 16 retested were HBsAg positive (11%). Anti-HBs was detected in 43/77 (56%) anti-HBc-reactive samples. Six samples were HBsAg
−
/anti-HBc
+
/anti-HBs
+
and contained HBV DNA, meeting the definition of occult HBV infection (OBI). OBIs had low HBV DNA loads (<10 IU/ml) and were genotype B (
n
= 1) or genotype D (
n
= 5). Pre-S/S and/or whole genome sequences were obtained from 47 randomly selected HBsAg-positive donors added to the previous 16. Genotype E was identified in 27 strains (57.5%), genotype D in 19 strains (40.5%), and genotype A2 in 1 strain (2%). Two outlier strains within genotype D ultimately were identified as recombinants of genotypes D and E with identical recombination points, suggesting circulating, infectious, recombinant strains. Anti-HBc screening does not appear to be a sustainable blood safety strategy because of the cost and the negative impact on the Sudanese blood supply, even when reduced by anti-HBs testing. Being at the junction between two main African HBV genotypes, genetic recombination occurred and became part of the molecular epidemiology of HBV in Sudan.
Multiple-Genome Comparison Reveals New Loci for
Mycobacterium
Species Identification
Authors: Dai Jianli , Chen Yuansha , Dean Susan , Morris J. Glenn , Salfinger Max , Johnson Judith A.
Published: November 2010

To identify loci useful for species identification and to enhance our understanding of the population structure and genetic variability of the genus
Mycobacterium
, we conducted a multiple-genome comparison of a total of 27 sequenced genomes in the suborder of
Corynebacterineae
(18 from the
Mycobacterium
genus, 7 from the
Corynebacterium
genus, 1 each from the
Nocardia
and
Rhodococcus
genera). Our study revealed 26 informative loci for species identification in
Mycobacterium
. The sequences from these loci were used in a phylogenetic analysis to infer the evolutionary relations of the 18 mycobacterial genomes. Among the loci that we identified,
rpoBC
,
dnaK
, and
hsp65
were amplified from 29 ATCC reference strains and 17 clinical isolates and sequenced. The phylogenetic trees generated from these loci show similar topologies. The newly identified
dnaK
locus is more discriminatory and more robust than the widely used
hsp65
locus. The length-variable
rpoBC
locus is the first intergenic locus between two protein-encoding genes being used for mycobacterial species identification. A multilocus sequence analysis system including the
rpoBC
,
dnaK
, and
hsp65
loci is a robust tool for accurate identification of
Mycobacterium
species.
Isolation of
Robinsoniella peoriensis
from Four Human Specimens
Authors: Gomez Eric , Gustafson Daniel R. , Colgrove Robin , Ly Tam , Santana Rafael , Rosenblatt Jon E. , Patel Robin
Published: November 2010

Robinsoniella peoriensis
is a recently described anaerobic, spore-forming, Gram-positive bacillus originally recovered from swine manure. We report four human cases in which
R. peoriensis
was isolated from clinical samples.
Age-Stratified Bayesian Analysis To Estimate Sensitivity and Specificity of Four Diagnostic Tests for Detection of
Cryptosporidium
Oocysts in Neonatal Calves
Authors: De Waele Valerie , Berzano Marco , Berkvens Dirk , Speybroeck Niko , Lowery Colm , Mulcahy Grace M. , Murphy Thomas M.
Published: November 2010

There is no gold standard diagnostic test for the detection of bovine cryptosporidiosis. Infection is usually highest in 2-week-old calves, and these calves also excrete high numbers of oocysts. These factors may give rise to variations in the sensitivity and specificity of the various diagnostic tests used to detect infection in calves of various ages. An age-stratified Bayesian analysis was carried out to determine the optimum diagnostic test to identify asymptomatic and clinical
Cryptosporidium
sp. infection in neonatal calves. Fecal samples collected from 82 calves at 1 week, 2 weeks, 3 weeks, and 4 weeks of age were subjected to the following tests: microscopic examination of smears stained with either phenol-auramine O or fluorescein isothiocyanate (FITC)-conjugated anti-
Cryptosporidium
monoclonal antibody, nested-PCR, and quantitative real-time PCR. The results confirmed a high prevalence of
Cryptosporidium
sp. infection, as well as a high level of oocyst excretion, in 2-week-old calves. The sensitivities of all the tests varied with the age of the calves. Quantitative real-time PCR proved to be the most sensitive and specific test for detecting infection irrespective of the age of the calf. The microscopic techniques were the least sensitive and exhibited only moderate efficiency with 2-week-old calves excreting large numbers of oocysts, the majority of which were diarrheic. It was concluded that, when interpreting the results of routine tests for bovine cryptosporidiosis, cognizance should be taken of the sensitivity of the tests in relation to the age of the calves and stage of infection.
The Kaposi's Sarcoma-Associated Herpesvirus G Protein-Coupled Receptor Contains an Immunoreceptor Tyrosine-Based Inhibitory Motif That Activates Shp2
Authors: Philpott Nicola , Bakken Thomas , Pennell Christopher , Chen Liwei , Wu Jie , Cannon Mark
Published: November 2010

The Kaposi's sarcoma-associated herpesvirus (KSHV) G protein-coupled receptor (vGPCR) is a constitutively active, highly angiogenic homologue of the interleukin-8 (IL-8) receptors that signals in part via the cytoplasmic protein tyrosine phosphatase Shp2. We show that vGPCR contains a bona fide immunoreceptor tyrosine-based inhibitory motif (ITIM) that binds and constitutively activates Shp2.
The Hydrophobic Domain of Infectious Bronchitis Virus E Protein Alters the Host Secretory Pathway and Is Important for Release of Infectious Virus
Authors: Ruch Travis R. , Machamer Carolyn E.
Published: November 2010

The coronavirus (CoV) E protein plays an important role in virus assembly. The E protein is made in excess during infection and has been shown to have ion channel activity in planar lipid bilayers. However, a role in infection for the unincorporated E or its ion channel activity has not been described. To further investigate the function of the infectious bronchitis virus (IBV) E protein, we developed a recombinant version of IBV in which the E protein was replaced by a mutant containing a heterologous hydrophobic domain. The mutant virus, IBV-EG3, was defective in release of infectious virus particles. Further characterization of IBV-EG3 revealed that damaged particles appeared to accumulate intracellularly. The phenotype of IBV-EG3 suggested that the hydrophobic domain of IBV E may be important for the forward trafficking of cargo, so we determined whether IBV E facilitated the delivery of cargo to the plasma membrane. Surprisingly, we found that IBV E, but not EG3, dramatically reduced the delivery of cargo to the plasma membrane by impeding movement through the Golgi complex. Furthermore, we observed that overexpression of IBV E, but not EG3, induced the disassembly of the Golgi complex. Finally, we determined that the delivery of IBV S to the plasma membrane was reduced in cells infected with wild-type-IBV compared to those infected with IBV-EG3. Our results indicated that the hydrophobic domain of IBV E alters the host secretory pathway to the apparent advantage of the virus.