bluuebunny/crossref_metadata_2025_split huggingface dataset:
Snail-dependent repression of the RhoGEF pebble is required for gastrulation consistency in Drosophila melanogaster
Authors: Murray Michael J. , Southall Tony D. , Liu Wenjie , Fraval Hamilton , Lorensuhewa Nirmal , Brand Andrea H. , Saint Robert 
Published: September 2012

Abstract
The Rho GTP exchange factor, Pebble (Pbl), long recognised as an essential activator of Rho during cytokinesis, also regulates mesoderm migration at gastrulation. Like other cell cycle components, pbl expression patterns broadly correlate with proliferative tissue. Surprisingly, in spite of its role in the early mesoderm, pbl is downregulated in the presumptive mesoderm before ventral furrow formation. Here, we show that this mesoderm-specific repression of pbl is dependent on the transcriptional repressor Snail (Sna). pbl repression was lost in sna mutants but was unaffected when Sna was ectopically expressed, showing that Sna is necessary, but not sufficient, for pbl repression. Using DamID, the first intron of pbl was identified as a Sna-binding region. Nine sites with the Sna-binding consensus motif CAGGT[GA] were identified in this intron. Mutating these to TAGGC[GA] abolished the ventral repression of pbl. Surprisingly, Sna-dependent repression of pbl was not essential for viability or fertility. Loss of repression did, however, increase the frequency of low-penetrance gastrulation defects. Consistent with this, expression of a pbl-GFP transgene in the presumptive mesoderm generated similar gastrulation defects. Finally, we show that a cluster of Snail-binding sites in the middle of the first intron of pbl orthologues is a conserved feature in the other 11 sequenced Drosophila species. We conclude that pbl levels are precisely regulated to ensure that there is enough protein available for its role in early mesoderm development but not so much as to inhibit the orderly progression of gastrulation.
Biosynthesis of clavam metabolites
Authors: Jensen Susan E 
Published: September 2012

Abstract
Naturally occurring clavam metabolites include the valuable β-lactamase inhibitor, clavulanic acid, as well as stereochemical variants with side-chain modifications, called the 5S clavams. Because of the clinical importance of clavulanic acid, most studies of clavam biosynthesis are based on the industrial producer species Streptomyces clavuligerus. Well-characterized early steps in clavam biosynthesis are outlined, and less well understood late steps in 5S clavam biosynthesis are proposed. The complex genetic organization of the clavam biosynthetic genes in S. clavuligerus is described and, where possible, comparisons with other producer species are presented.
Experimental investigation on the evolution of the modulation instability with dissipation
Authors: Ma Y. , Dong G. , Perlin M. , Ma X. , Wang G. 
Published: September 2012

AbstractAn experimental investigation focusing on the effect of dissipation on the evolution of the Benjamin–Feir instability is reported. A series of wave trains with added sidebands, and varying initial steepness, perturbed amplitudes and frequencies, are physically generated in a long wave flume. The experimental results directly confirm the stabilization theory of Segur et al. (J. Fluid Mech., vol. 539, 2005, pp. 229–271), i.e. dissipation can stabilize the Benjamin–Feir instability. Furthermore, the experiments reveal that the effect of dissipation on modulational instability depends strongly on the perturbation frequency. It is found that the effect of dissipation on the growth rates of the sidebands for the waves with higher perturbation frequencies is more evident than on those of waves with lower perturbation frequencies. In addition, numerical simulations based on Dysthe’s equation with a linear damping term included, which is estimated from the experimental data, can predict the experimental results well if the momentum integral of the wave trains is conserved during evolution.
A throttling mechanism sustaining a hole tone feedback system at very low Mach numbers
Authors: Matsuura K. , Nakano M. 
Published: September 2012

AbstractThis study investigates the sound produced when a jet, issued from a circular nozzle or hole in a plate, goes through a similar hole in a second plate. The sound, known as a hole tone, is encountered in many practical engineering situations. Direct computations of a hole tone feedback system were conducted. The mean velocity of the air jet was 10 m s−1. The nozzle and the end plate hole both had a diameter of 51 mm, and the impingement length between the nozzle and the end plate was 50 mm. The computational results agreed well with past experimental data in terms of qualitative vortical structures, the relationship between the most dominant hole tone peak frequency and the jet speed, and downstream growth of the mean jet profiles. Based on the computational results, the shear-layer impingement on the hole edge, the resulting propagation of pressure waves and the associated vortical structures are discussed. To extract dominant unsteady behaviours of the hole tone phenomena, a snapshot proper orthogonal decomposition (POD) analysis of pressure fluctuation fields was conducted. It was found that the pressure fluctuation fields and the time variation of mass flows through the end plate hole were dominantly expressed by the first and second POD modes, respectively. Integrating the computational results, an axisymmetric throttling mechanism linking mass flow rates through the hole, vortex impingement and global pressure propagation, is proposed.
Simulation and modelling of slip flow over surfaces grafted with polymer brushes and glycocalyx fibres
Authors: Deng Mingge , Li Xuejin , Liang Haojun , Caswell Bruce , Karniadakis George Em 
Published: September 2012

AbstractFabrication of functionalized surfaces using polymer brushes is a relatively simple process and parallels the presence of glycocalyx filaments coating the luminal surface of our vasculature. In this paper, we perform atomistic-like simulations based on dissipative particle dynamics (DPD) to study both polymer brushes and glycocalyx filaments subject to shear flow, and we apply mean-field theory to extract useful scaling arguments on their response. For polymer brushes, a weak shear flow has no effect on the brush density profile or its height, while the slip length is independent of the shear rate and is of the order of the brush mesh size as a result of screening by hydrodynamic interactions. However, for strong shear flow, the polymer brush is penetrated deeper and is deformed, with a corresponding decrease of the brush height and an increase of the slip length. The transition from the weak to the strong shear regime can be described by a simple ‘blob’ argument, leading to the scaling ${\dot {\gamma } }_{0} \propto {\sigma }^{3/ 2} $, where ${\dot {\gamma } }_{0} $ is the critical transition shear rate and $\sigma $ is the grafting density. Furthermore, in the strong shear regime, we observe a cyclic dynamic motion of individual polymers, causing a reversal in the direction of surface flow. To study the glycocalyx layer, we first assume a homogeneous flow that ignores the discrete effects of blood cells, and we simulate microchannel flows at different flow rates. Surprisingly, we find that, at low Reynolds number, the slip length decreases with the mean flow velocity, unlike the behaviour of polymer brushes, for which the slip length remains constant under similar conditions. (The slip length and brush height are measured with respect to polymer mesh size and polymer contour length, respectively.) We also performed additional DPD simulations of blood flow in a tube with walls having a glycocalyx layer and with the deformable red blood cells modelled accurately at the spectrin level. In this case, a plasma cell-free layer is formed, with thickness more than three times the glycocalyx layer. We then find our scaling arguments based on the homogeneous flow assumption to be valid for this physiologically correct case as well. Taken together, our findings point to the opposing roles of conformational entropy and bending rigidity – dominant effects for the brush and glycocalyx, respectively – which, in turn, lead to different flow characteristics, despite the apparent similarity of the two systems.
Introduction
Authors: Cooke Glenn R. 
Published: September 2012

Queensland's heritage city of Maryborough was the focus of the Australian Garden History Society's 32nd Annual Conference, held from 19–21 August 2011. The Society is again delighted to collaborate with Queensland Review to bring the papers from this conference to publication, just as it did with those of the 2003 conference. Maryborough was selected for this event because the city centre is remarkably intact and coherent, and because of the appeal of its numerous charming ‘Queenslander’ houses to Southern delegates. The topics of the conference and the tours organised by the conference committee confirmed Garden History Society chair John Dwyer's opening description of Maryborough, quoted from the Australian National Trust's 1982 Historic Places publication, as ‘one of the four most charming places in Australia’.
EFFECTS OF SALINE WATER ON WATER STATUS, YIELD AND FRUIT QUALITY OF WILD (SOLANUM CHILENSE) AND DOMESTICATED (SOLANUM LYCOPERSICUM VAR. CERASIFORME) TOMATOES
Authors: MARTÍNEZ JUAN-PABLO , ANTÚNEZ ALEJANDRO , PERTUZÉ RICARDO , ACOSTA MARIA DEL PILAR , PALMA XIMENA , FUENTES LIDA , AYALA ANIBAL , ARAYA HECTOR , LUTTS STANLEY 
Published: September 2012

SUMMARYFarmers around the world are concerned about the effects of human-induced salinity on crop yield and quality. Therefore, researchers are actively testing wild relatives of cultivated plants to identify candidates to improve crop performance under salt stress. A study was conducted to understand the effects of salt stress (Sodium chloride, NaCl) on cultivated tomato species (Solanum lycopersicum var. cerasiforme L.) and a wild tomato relative (Solanum chilense Dun.) from the Northern part of Chile. Plants were cultivated hydroponically under controlled environmental conditions for 112 days with nutrient solution containing 0 mM (3 dS m−1), 40 mM (6 dS m−1) and 80-mM (9 dS m−1) NaCl. Salt stress reduced the shoot biomass in S. lycopersicum but not in S. chilense. Both species were able to maintain the leaf water content; however, the cultivated S. lycopersicum showed osmotic adjustment, while S. chilense did not. Salt stress reduced the total fruit yield in S. lycopersicum based on a decrease in the mean fruit weight, but it had no impact on the number of fruits per plant. In contrast, salt stress had no significant impact on the fruit yield in S. chilense. Salt stress increased the total soluble solids content in S. lycopersicum and the titratable acidity in S. chilense. It was concluded that S. chilense displays a contrasting behaviour in response to prolonged exposure to moderate salinity compared with S. lycopersicum, and that this related species could be an interesting plant for breeding purposes.
Experimental infection of laboratory mice with twoBartonella tribocorumstrains from wildMusspecies: a homologous host-bacteria model system at the genus level
Authors: COLTON L. , KOSOY M. 
Published: September 2012

SUMMARYTo date no experimental infection studies have been conducted in laboratory mice usingMusspp. bartonella strains. Therefore we designed a study to evaluate thein vivoinfection characteristics of 2Bartonella tribocorumstrains from wildMusspp. in laboratory mice with the aim of developing a mouse model that reproduces characteristics of naturally acquired bartonella infections in rodents. Groups of outbred CD1 female mice were subcutaneously inoculated with low doses of 2 mouse bartonella strains (10, 100, and 1000 bacteria/mouse). Blood was collected weekly for 27 weeks to evaluate bacteraemia kinetics in infected mice. Mouse urine collected during weeks 3–6 post-inoculation was also tested for viable bacteria to determine whether urine might serve as a source of bacterial transmission. Mice were susceptible to infection with both strains. Bacteraemias in mice lasted up to 25 weeks, sometimes with abacteraemic intervals, and achieved levels up to 107cfu/ml of blood. Temporal lags in bacteraemia onset of up to 19 weeks in length were noted at different inoculum doses. No viable bacteria were detected in mouse urine. Bacteraemic mice displayed characteristics of infection similar to those observed in natural rodent hosts during longitudinal field studies. This mouse model of persistent bacteraemia should be suitable for a variety of experimental uses.
An alternative to killing? Treatment of reservoir hosts to control a vector and pathogen in a susceptible species
Authors: PORTER R. , NORMAN R. A. , GILBERT L. 
Published: September 2012

SUMMARYParasite-mediated apparent competition occurs when one species affects another through the action of a shared parasite. One way of controlling the parasite in the more susceptible host is to manage the reservoir host. Culling can cause issues in terms of ethics and biodiversity impacts, therefore we ask: can treating, as compared to culling, a wildlife host protect a target species from the shared parasite? We used Susceptible Infected Recovered (SIR) models parameterized for the tick-borne louping ill virus (LIV) system. Deer are the key hosts of the vector (Ixodes ricinus) that transmits LIV to red grouse Lagopus lagopus scoticus, causing high mortality. The model was run under scenarios of varying acaricide efficacy and deer densities. The model predicted that treating deer can increase grouse density through controlling ticks and LIV, if acaricide efficacies are high and deer densities low. Comparing deer treated with 70% acaricide efficacy with a 70% cull rate suggested that treatment may be more effective than culling if initial deer densities are high. Our results will help inform tick control policies, optimize the targeting of control methods and identify conditions where host management is most likely to succeed. Our approach is applicable to other host-vector-pathogen systems.
Structure and organization of an avian haemosporidian assemblage in a Neotropical savanna in Brazil
Authors: FECCHIO ALAN , LIMA MARCOS ROBALINHO , SVENSSON-COELHO MARIA , MARINI MIGUEL ÂNGELO , RICKLEFS ROBERT E. 
Published: September 2012

SUMMARYStudies on avian haemosporidia are on the rise, but we still lack a basic understanding of how ecological and evolutionary factors mold the distributions of haemosporidia among species in the same bird community. We studied the structure and organization of a local avian haemosporidian assemblage (generaPlasmodiumandHaemoproteus) in the Cerrado biome of Central Brazil for 5 years. We obtained 790 blood samples from 54 bird species of which 166 (21%) were infected with haemosporidians based on molecular diagnostics. Partial sequences of the parasite cytochrome b gene revealed 18 differentiated avian haemosporidian lineages. We also analysed the relationship of life-history traits (i.e., nesting height, migration status, nest type, sociality, body mass, and embryo development period) of the 14 most abundant bird species with the prevalence of avian haemosporidia. It was found that host species that bred socially presented a higher prevalence ofHaemoproteus(Parahaemoproteus) than bird species that bred in pairs. Thus, aspects of host behaviour could be responsible for differential exposure to vectors. The assemblage of avian haemosporidia studied here also confirms a pattern that is emerging in recent studies using molecular markers to identify avian haemosporidians, namely that many lineages are host generalists.
A true gift of mother earth: the use and significance of obsidian at Çatalhöyük
Authors: Carter Tristan 
Published: September 2012

AbstractThis paper reviews 50 years of obsidian studies at Neolithic Çatalhöyük in the Konya plain, central Anatolia. A number of key issues are addressed: (1) the source of the site's raw materials, the means and forms by which the obsidian was introduced to the site and the role of Çatalhöyük in the supra-regional dissemination of these raw materials; (2) the alleged gender associations of certain obsidian goods in the burial record and beyond; (3) a more general consideration of the social significance of the circulation and consumption of obsidian at the site, including the phenomena of hoarding and gifting, plus the important role of projectiles in the creation of social identities and various forms of ritual behaviour, not least the termination of the life of a building/individual; (4) the technotypological and raw material variability through time; (5) the use of obsidian in daily practice and craft-working.
Local authority and civic Hellenism: Tarcondimotus, Hierapolis-Castabala and the cult of Perasia
Authors: Andrade Nathanael 
Published: September 2012

AbstractIn the mid first century BC, a dynast named Tarcondimotus asserted his authority over parts of Smooth Cilicia. Tarcondimotus' successful accommodation of the differing expectations of Roman magistrates, local Greeks and Cilicians was connected to his patronage of the Greekpolisof Hierapolis-Castabala. Through such patronage, he collaborated with municipal elites to interweave Greek and local traditions into the city's culture and cult in ways that produced innovative expressions of civic Hellenism. Likewise, while Hierapolis-Castabala was under Tarcondimotus' protection, its cult to the goddess Perasia, a local manifestation of the ancient Hittite deity Kubaba, embodied these unique cultural expressions. During the Hellenistic and Roman periods, Perasia retained her traditional name and her cult enjoyed distinctively local rites in which her priestesses walked upon fiery coals. Such unique qualities prevented Greeks and Romans during the centuries following Tarcondimotus' rule from associating her with any single goddess worshipped in Greece or Italy. In sum, by patronising Hierapolis-Castabala, Tarcondimotus presented himself as the defender of Greek civic life and theHierapolitaiwere able to persist in their unique expressions of Greek civic performance and cult in the turbulent transitional period between Seleucid and Roman rule.
Certain properties for crossed products by automorphisms with a certain non-simple tracial Rokhlin property
Authors: FANG XIAOCHUN , FAN QINGZHAI 
Published: September 2012

AbstractLet $\Omega $ be a class of unital $C^*$-algebras. Then any simple unital $C^*$-algebra $A\in \mathrm {TA}(\mathrm {TA}\Omega )$ is a $\mathrm {TA}\Omega $ algebra. Let $A\in \mathrm {TA}\Omega $ be an infinite-dimensional $\alpha $-simple unital $C^*$-algebra with the property SP. Suppose that $\alpha :G\to \mathrm {Aut}(A)$ is an action of a finite group $G$ on $A$ which has a certain non-simple tracial Rokhlin property. Then the crossed product algebra $C^*(G,A,\alpha )$ belongs to $\mathrm {TA}\Omega $.
Notes on Verdi's I due Foscari
Authors: Giger Andreas 
Published: September 2012

AbstractThe preparation of the critical edition of Verdi's I due Foscari has drawn attention to two overlooked sources: an early scenario attributed to Andrea Maffei and an early manuscript copy with various layers of corrections. This article questions the scenario's attribution to Maffei, revising the opera's early history. It furthermore identifies one of the layers in the manuscript copy as being in Verdi's hand, showing that the composer's role in fine-tuning a libretto at this early stage in his career was greater than has so far been possible to show.
Melancholy and allegory inDie Frau ohne Schatten
Authors: Shirley Hugo 
Published: September 2012

AbstractDie Frau ohne Schatten(The Woman without a Shadow, 1917) was conceived as Richard Strauss and Hugo von Hofmannsthal's ‘chief joint work’, and its central message has been read as an allegory of artistic collaboration and social engagement. This article calls upon Walter Benjamin's theory of allegory to enrich such an interpretation and unravel the opera's positive conclusion as an inadequate cure for the artistic melancholy of thefin de siècle. While Strauss successfully engaged with allegory to portray two of the opera's characters – the infertile Emperor and Empress – he was unable, for his own philosophical reasons expressed in the contemporaneousEine Alpensinfonie(1915), to ratify Hofmannsthal's hope, rooted in his ‘Chandos Crisis’, of creating an aesthetic totality, of reconstituting the symbol that Benjamin, in his later writings, pits against allegory.
Castrati and impresarios in London: two mid-eighteenth-century lawsuits
Authors: Duncan Cheryll 
Published: September 2012

AbstractTwo King's Bench lawsuits in The National Archives of the UK contain new information about the activities of castrati working in mid-eighteenth-century London. Monticelli v. Sackville (1748) confirms Horace Walpole's testimony that singers employed by the Earl of Middlesex's opera company received enormous salaries. Manfredini v. Geminiani (1751) preserves details of a contract of employment between singer and impresario that went disastrously wrong for both parties. An account of the London careers of the main protagonists is supplied to contextualise the new information.
Frederick's Athens: crushing superstition and resuscitating the marvellous at the Königliches Opernhaus, Berlin
Authors: Forment Bruno 
Published: September 2012

AbstractFrom 1748 onwards, the marvellous made a comeback in opera seria via the Königliches Opernhaus in Berlin. The striking resurgence of myth and magic in the predominantly historical operatic genre appears to bespeak a growing interest in Lullian tragédie en musique, which in turn can be associated with Frederick II's French orientation in literary and philosophical matters. But how did deities, sorcerers and Louis quatorzien imports chime with Frederick's notorious resistance to superstition and divinely ordained kingship? The juxtaposition of the relevant operas with theoretical writings from Friderician Prussia yields a multi-faceted, somewhat paradoxical answer, revealing that the marvellous, alongside nourishing a new type of operatic spectacle, served Frederick as a vehicle to impart his philosophical agenda to his state, a former centre of Pietism.