bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effective transition of steady flow over a square leading-edge plate
Authors: Thompson Mark C. 
Published: March 2012

AbstractPrevious experimental studies have shown that the steady recirculation bubble that forms as the flow separates at the leading-edge corner of a long plate, becomes unsteady at relatively low Reynolds numbers of only a few hundreds. The reattaching shear layer irregularly releases two-dimensional vortices, which quickly undergo three-dimensional transition. Similar to the flow over a backward-facing step, this flow is globally stable at such Reynolds numbers, with transition to a steady three-dimensional flow as the first global instability to occur as the Reynolds number is increased to 393. Hence, it appears that the observed flow behaviour is governed by transient growth of optimal two-dimensional transiently growing perturbations (constructed from damped global modes) rather than a single three-dimensional unstable global mode. This paper quantifies the details of the transient growth of two- and three-dimensional optimal perturbations, and compares the predictions to other related cases examined recently. The optimal perturbation modes are shown to be highly concentrated in amplitude in the vicinity of the leading-edge corners and evolve to take the local shape of a Kelvin–Helmholtz shear-layer instability further downstream. However, the dominant mode reaches a maximum amplitude downstream of the position of the reattachment point of the shear layer. The maximum energy growth increases at 2.5 decades for each increment in Reynolds number of 100. Maximum energy growth of the optimal perturbation mode at a Reynolds number of 350 is greater than $1{0}^{4} $, which is typically an upper limit of the Reynolds number range over which it is possible to observe steady flow experimentally. While transient growth analysis concentrates on the evolution of wavepackets rather than continuous forcing, this appears consistent with longitudinal turbulence levels of up to 1 % for some water tunnels, and the fact that the optimal mode is highly concentrated close to the leading-edge corner so that an instantaneous projection of a perturbation field from a noisy inflow onto the optimal mode can be significant. Indeed, direct simulations with inflow noise reveal that a root-mean-square noise level of just 0.1 % is sufficient to trigger some unsteadiness at $\mathit{Re}= 350$, while a 0.5 % level results in sustained shedding. Three-dimensional optimal perturbation mode analysis was also performed showing that at $\mathit{Re}= 350$, the optimal mode has a spanwise wavelength of 11.7 plate thicknesses and is amplified 20 % more than the two-dimensional optimal disturbance. The evolved three-dimensional mode shows strong streamwise vortical structures aligned at a shallow angle to the plate top surface.
On the connection between the magneto-elliptic and magneto-rotational instabilities
Authors: Mizerski Krzysztof A. , Lyra Wladimir 
Published: March 2012

AbstractIt has recently been suggested that the magneto-rotational instability (MRI) is a limiting case of the magneto-elliptic instability (MEI). This limit is obtained for horizontal modes in the presence of rotation and an external vertical magnetic field, when the aspect ratio of the elliptic streamlines tends to infinite. In this paper we unveil the link between these previously unconnected mechanisms, explaining both the MEI and the MRI as different manifestations of the same magneto-elliptic-rotational instability (MERI). The growth rates are found and the influence of the magnetic and rotational effects is explained, in particular the effect of the magnetic field on the range of negative Rossby numbers at which the horizontal instability is excited. Furthermore, we show how the horizontal rotational MEI in the rotating shear flow limit is linked to the MRI by the use of the local shearing box model, typically used in the study of accretion discs. In such a limit the growth rates of the two instability types coincide for any power-law-type background angular velocity radial profile with negative exponent corresponding to the value of the Rossby number of the rotating shear flow. The MRI requirement for instability is that the background angular velocity profile is a decreasing function of the distance from the centre of the disc, which corresponds to the horizontal rotational MEI requirement of negative Rossby numbers. Finally a physical interpretation of the horizontal instability, based on a balance between the strain, the Lorentz force and the Coriolis force, is given.
CHIEF FACTORS COVERED BY PROJECTORS OF SOLUBLE LEIBNIZ ALGEBRAS
Authors: BARNES DONALD W. 
Published: March 2012

AbstractLet 𝔉 be a saturated formation of soluble Leibniz algebras. LetKbe an 𝔉-projector andA/Ba chief factor of the soluble Leibniz algebraL. It is well known that ifA/Bis 𝔉-central, thenKcoversA/B. I prove the converse: ifKcoversA/B, thenA/Bis 𝔉-central.
Changes in aphid probing behaviour as a function of insect age and plant resistance level
Authors: Pompon J. , Pelletier Y. 
Published: March 2012

AbstractAphids perform a series of behaviours to assess feeding suitability and, hence, to select a plant. Little information, however, is available on such behaviour after aphids have settled on a plant. Observation of probing behaviour over an extended period of time can improve our understanding of insect-plant interactions and is instrumental in the study of crop resistance. Here, we assessed the influence of aphid age and plant resistance level on aphid behaviour. An electrical penetration graph (EPG) technique was implemented to monitor the behaviour of potato aphid, Macrosiphum euphorbiae, alates on potato, Solanum tuberosum, and on both a susceptible and a resistant genotype of a wild Solanum species, S. chomatophilum. The behaviour was measured at daily intervals for the first seven days following adult emergence. The results indicated independent and interacting effects of aphid age and plant genotype on probing behaviour. Some behavioural discrepancies between susceptible and resistant genotypes were only observed after the first day, thus highlighting the limits of punctual one-day behavioural studies to assess plant resistance mechanisms. Our work supports the hypothesis that aphids continuously adapt their behaviour to the plant characteristics.
WEYL TYPE THEOREMS FOR FUNCTIONS OF OPERATORS
Authors: ZHU SEN , LI CHUN GUANG , ZHOU TING TING 
Published: March 2012

AbstractA-Weyl's theorem and property (ω), as two variations of Weyl's theorem, were introduced by Rakočević. In this paper, we study a-Weyl's theorem and property (ω) for functions of bounded linear operators. A necessary and sufficient condition is given for an operator T to satisfy that f(T) obeys a-Weyl's theorem (property (ω)) for all f ∈ Hol(σ(T)). Also we investigate the small-compact perturbations of operators satisfying a-Weyl's theorem (property (ω)) in the setting of separable Hilbert spaces.
ON THE WILLMORE FUNCTIONAL OF 2-TORI IN SOME PRODUCT RIEMANNIAN MANIFOLDS
Authors: WANG PENG 
Published: March 2012

AbstractWe discuss the minimum of Willmore functional of torus in a Riemannian manifoldN, especially for the case thatNis a product manifold. We show that whenN=S2×S1, the minimum ofW(T2) is 0, and whenN=R2×S1, there exists no torus having least Willmore functional. WhenN=H2(−c) ×S1, andx= γ ×S1, the minimum ofW(x) is$2\pi^2\sqrt{c}$.
GROUPS THAT INVOLVE FINITELY MANY PRIMES AND HAVE ALL SUBGROUPS SUBNORMAL II
Authors: SMITH HOWARD 
Published: March 2012

AbstractIt is shown that if G is a hypercentral group with all subgroups subnormal, and if the torsion subgroup of G is a π-group for some finite set π of primes, then G is nilpotent. In the case where G is not hypercentral there is a section of G that is much like one of the well-known Heineken-Mohamed groups. It is also shown that if G is a residually nilpotent group with all subgroups subnormal whose torsion subgroup satisfies the above condition then G is nilpotent.
PARA-BLASCHKE ISOPARAMETRIC HYPERSURFACES IN A UNIT SPHERE Sn + 1(1)
Authors: SHU SHICHANG , SU BIANPING 
Published: March 2012

AbstractLet A = ρ2∑i,jAijθi ⊗ θj and B = ρ2∑i,jBij θi ⊗ θj be the Blaschke tensor and the Möbius second fundamental form of the immersion x. Let D = A + λB be the para-Blaschke tensor of x, where λ is a constant. If x: Mn ↦ Sn + 1(1) is an n-dimensional para-Blaschke isoparametric hypersurface in a unit sphere Sn + 1(1) and x has three distinct Blaschke eigenvalues one of which is simple or has three distinct Möbius principal curvatures one of which is simple, we obtain the full classification theorems of the hypersurface.
RINGS WHOSE CYCLIC MODULES ARE DIRECT SUMS OF EXTENDING MODULES
Authors: AYDOĞDU PINAR , ER NOYAN , ERTAŞ NİL ORHAN 
Published: March 2012

AbstractDedekind domains, Artinian serial rings and right uniserial rings share the following property: Every cyclic right module is a direct sum of uniform modules. We first prove the following improvement of the well-known Osofsky-Smith theorem: A cyclic module with every cyclic subfactor a direct sum of extending modules has finite Goldie dimension. So, rings with the above-mentioned property are precisely rings of the title. Furthermore, a ring R is right q.f.d. (cyclics with finite Goldie dimension) if proper cyclic (≇ RR) right R-modules are direct sums of extending modules. R is right serial with all prime ideals maximal and ∩n ∈ ℕJn = Jm for some m ∈ ℕ if cyclic right R-modules are direct sums of quasi-injective modules. A right non-singular ring with the latter property is right Artinian. Thus, hereditary Artinian serial rings are precisely one-sided non-singular rings whose right and left cyclic modules are direct sums of quasi-injectives.
ON THE GEOMETRY OF ORBIT CLOSURES FOR REPRESENTATION-INFINITE ALGEBRAS
Authors: CHINDRIS CALIN 
Published: March 2012

AbstractFor the Kronecker algebra, Zwara found in [14] an example of a module whose orbit closure is neither unibranch nor Cohen-Macaulay. In this paper, we explain how to extend this example to all representation-infinite algebras with a preprojective component.
Daniel 7, Intertextuality, and the History of Israel's Cult
Authors: Boyarin Daniel 
Published: March 2012

Professor Hanan Eshel, in memoriamAncient and modern readers have offered two basic interpretations of the “[One like a] Son of Man” () in Dan 7:13. One line of interpretation holds that the One like a Son of Man is a symbol of a collective, namely, the faithful Israelites at the time of the Maccabean revolt.1 The other basic line of interpretation sees the One like a Son of Man as a divine figure of one sort or another, a second God, a son of God, or an archangel.
TWO SONS AND A DAUGHTER: SEX COMPOSITION AND WOMEN'S REPRODUCTIVE BEHAVIOUR IN MADHYA PRADESH, INDIA
Authors: EDMEADES JEFFREY , PANDE ROHINI , MACQUARRIE KERRY , FALLE TINA , MALHOTRA ANJU 
Published: March 2012

SummaryThis article examines how the sex composition of women's current children at the start of a pregnancy interval influences both fertility desires and the full range of reproductive actions women may take to realize them, including temporary contraception, abortion and sterilization, in Madhya Pradesh, India, where popular notions of ideal family size and sex composition are dominated by son preference. The analysis is conducted using a dataset of 9127 individual pregnancy intervals from a 2002 statewide representative survey of 2444 women aged 15–39 with at least one child. The results indicate that women's preferences go beyond a singular preference for male children, with the preferred composition of children being two boys and one girl. Women with this composition are 90% less likely to report having wanted another pregnancy (OR 0.097, p<0.01) relative to those with two girls. These preferences have significant implications for reproductive actions. While sex composition has no statistically significant effect on the use of temporary contraception, those with the preferred sex composition are twice as likely to attempt abortion (OR 2.436, p<0.01) and twelve times more likely to be sterilized (OR 12.297, p<0.01) relative to those with two girls only.
Self-modulated wakefield acceleration in a centimetre self-guiding channel
Authors: KAMPERIDIS C. , BELLEI C. , BOURGEOIS N. , KALUZA M. C. , KRUSHELNICK K. , MANGLES S. P. D. , MARQUES J. R. , NAGEL S. R. , NAJMUDIN Z. 
Published: March 2012

AbstractSelf-modulated wakefield acceleration was investigated at densities down to ~4 × 1018 cm−3 by propagating the 50 TW 300 fs LULI laser in helium gas jets at lengths up to 1 cm. Long interaction lengths were achieved by closer matching of the initial focal spot size to the matched spot size for these densities. Electrons with energies extending to 180 MeV were observed in broad energy spectra which show some evidence for non-Maxwellian features at high energy. Two-dimensional PIC simulations indicate that the intial laser pulse breaks up into small pulselets that are eventually compressed and focused inside the first few plasma periods, leading to a ‘bubble-like’ acceleration of electron bunches.
Spatio-temporal distributions of zoobenthos in soft substratum of Izmir Bay (Aegean Sea, eastern Mediterranean), with special emphasis on alien species and ecological quality status
Authors: Çinar Melıh Ertan , Katagan Tuncer , Öztürk Bılal , Bakir Kerem , Dagli Ertan , Açik Sermın , Dogan Alper , Bıtlıs Banu 
Published: March 2012

The soft-bottom zoobenthic community structure of Izmir Bay was examined seasonally at eight stations (depth-range: 19–67 m) in 2009. A total of 427 species were found. Polychaeta had the highest number of species (50% of total species) and individuals (75%), whereas Echinodermata possessed the highest biomass (47%). The number of species varied from 3 to 79 (0.1 m−2), the density from 60 to 5360 ind.m−2, and the biomass from 1 to 530 g.m−2. The most numerically dominant species were the polychaetesAricidea claudiae, Streblospio gynobranchiata, Levinsenia demiriandSternaspis scutata. The distribution of zoobenthos was strongly related to spatial differences in total organic carbon, sediment texture and depth among different regions of the bay rather than temporal differences among seasons. However, significant seasonal variability in community structure (mainly differences in the relative abundance of species) was present. The inner region of the bay can be classified as ‘poor’ or ‘bad’ based on the results of biotic indices (H′, AMBI, m-AMBI and BENTIX). Among biotic indices, only H′ and m-AMBI appeared to be capable of explaining the bay's benthic quality status. Thirteen alien species were also found.Streblospio gynobranchiata, Prionospio pulchra, Pseudopolydora paucibranchiataandPolydora cornutaformed dense populations in the inner most polluted part of the bay and are considered to be new pollution indicator species in the eastern Mediterranean Sea.
Direct and Inverse Solutions with Geodetic Latitude in Terms of Longitude for Rhumb Line Sailing
Authors: Tseng Wei-Kuo , Earle Michael A. , Guo Jiunn-Liang 
Published: March 2012

In this paper, equations are established to solve problems of Rhumb Line Sailing (RLS) on an oblate spheroid. Solutions are provided for both the inverse problem and the direct problem, thereby providing a complete solution to RLS. Development of these solutions was achieved in part by means of computer based symbolic algebra. The inverse solution described attains a high degree of accuracy for distance and azimuth. The direct solution has been obtained from a solution for latitude in terms of distance derived with the introduction of an inverse series expansion of meridian arc-length via the rectifying latitude. Also, a series to determine latitude at any longitude has been derived via the conformal latitude. This was achieved through application of Hermite's Interpolation Scheme or the Lagrange Inversion Theorem. Numerical examples show that the algorithms are very accurate and that the differences between original data and recovered data after applying the inverse or direct solution of RLS to recover the data calculated by the direct or inverse solution are very small. It reveals that the algorithms provided here are suitable for programming implementation and can be applied in the areas of maritime routing and cartographical computation in Graphical Information System (GIS) and Electronic Chart Display and Information System (ECDIS) environments.
Estimating the variability in the risk of infection for hepatitis C in the Glasgow injecting drug user population
Authors: SUTTON A. J. , McDONALD S. A. , PALMATEER N. , TAYLOR A. , HUTCHINSON S. J. 
Published: March 2012

SUMMARYGlasgow (Scotland's largest city) has a high prevalence of injecting drug use and has one of the highest prevalences of hepatitis C virus (HCV) infection in injecting drug users (IDUs) in Western Europe. HCV prevalence data from surveys of Glasgow's IDUs from 1990 to 2007 were utilized and a model was applied that described the prevalence of HCV as a function of the rate (force) of infection. Force-of-infection estimates for HCV that may vary over time and injecting career length over a range of variables were investigated. New initiates to injecting were found to be at increased risk of HCV infection, with being recruited from a street location and reporting injecting in prison leading to a significant increase in the risk of infection in new initiates. These results indicate areas of importance for the planning of public health measures that target the IDU population.
Bartonellainfection in urban and rural dogs from the tropics: Brazil, Colombia, Sri Lanka and Vietnam
Authors: BRENNER E. C. , CHOMEL B. B. , SINGHASIVANON O.-U. , NAMEKATA D. Y. , KASTEN R. W. , KASS P. H. , CORTÉS-VECINO J. A. , GENNARI S. M. , RAJAPAKSE R. P. , HUONG L. T. , DUBEY J. P. 
Published: March 2012

SUMMARYDogs can be infected by a wide range ofBartonellaspp., but limited studies have been conducted in tropical urban and rural dog populations. We aimed to determineBartonellaantibody prevalence in 455 domestic dogs from four tropical countries and detectBartonellaDNA in a subset of these dogs.Bartonellaantibodies were detected in 38 (8·3%) dogs, including 26 (10·1%) from Colombia, nine (7·6%) from Brazil, three (5·1%) from Sri Lanka and none from Vietnam. DNA extraction was performed for 26 (63%) of the 41 seropositive and 10 seronegative dogs. Four seropositive dogs were PCR positive, including two Colombian dogs, infected withB. rochalimaeandB. vinsoniisubsp.berkhoffii, and two Sri Lankan dogs harbouring sequences identical to strain HMD described in dogs from Italy and Greece. This is the first detection ofBartonellainfection in dogs from Colombia and Sri Lanka and identification ofBartonellastrain HMD from Asia.
Exploiting random intercepts: Two case studies in sociophonetics
Authors: Drager Katie , Hay Jennifer 
Published: March 2012

AbstractAn increasing number of sociolinguists are using mixed effects models, models which allow for the inclusion of both fixed and random predicting variables. In most analyses, random effect intercepts are treated as a by-product of the model; they are viewed simply as a way to fit a more accurate model. This paper presents additional uses for random effect intercepts within the context of two case studies. Specifically, this paper demonstrates how random intercepts can be exploited to assist studies of speaker style and identity and to normalize for vocal tract size within certain linguistic environments. We argue that, in addition to adopting mixed effect modeling more generally, sociolinguists should view random intercepts as a potential tool during analysis.
Acoustic correlates of rhythm in New Zealand English: A diachronic study
Authors: Nokes Jacqui , Hay Jennifer 
Published: March 2012

AbstractThis paper reports on a large-scale diachronic investigation into the timing of New Zealand English (NZE), which points to changes in its rhythmic structure. The Pairwise Variability Index (PVI) was used to measure the mean variation in duration, intensity, and pitch of successive vowels in the speech of over 500 New Zealanders, born between 1851 and 1988. Normalized vocalic PVIs for duration have reduced over time, after allowing for changes in speech rate, supporting existing findings that stressed and unstressed vowels are less differentiated by duration in modern NZE than in other varieties of English. Rhythmically, syllable duration may be playing a reduced role in signalling prominence in NZE. This is supported by the finding that there have been contemporaneous changes in pitch and intensity variation. We discuss external and internal influences on the timing of NZE, including contact with Māori, the emergence of Māori English, and diachronic vowel shift.
Proofs for free
Authors: BERNARDY JEAN-PHILIPPE , JANSSON PATRIK , PATERSON ROSS 
Published: March 2012

AbstractReynolds' abstraction theorem (Reynolds, J. C. (1983) Types, abstraction and parametric polymorphism,Inf. Process.83(1), 513–523) shows how a typing judgement in System F can be translated into a relational statement (in second-order predicate logic) about inhabitants of the type. We obtain a similar result for pure type systems (PTSs): for any PTS used as a programming language, there is a PTS that can be used as a logic for parametricity. Types in the source PTS are translated to relations (expressed as types) in the target. Similarly, values of a given type are translated to proofs that the values satisfy the relational interpretation. We extend the result to inductive families. We also show that the assumption that every term satisfies the parametricity condition generated by its type is consistent with the generated logic.
Predictors of physical activity change during adolescence: a 3·5-year follow-up
Authors: Dumith Samuel C , Gigante Denise P , Domingues Marlos R , Hallal Pedro C , Menezes Ana MB , Kohl Harold W 
Published: March 2012

AbstractObjectiveTo investigate the predictors of change in physical activity (PA) from early to mid adolescence in a cohort of adolescents.DesignProspective, population-based birth cohort study. PA level was evaluated by means of questionnaire, and was analysed in continuous form (min/week) and as a trajectory (inactive–inactive, inactive–active, active–inactive, active–active) based on the cut-off point of 300 min/week.SettingPelotas, a city of 340 000 inhabitants in southern Brazil.SubjectsAdolescents (n4120) followed from 11 to 15 years of age.ResultsMaternal PA change and more exposure to outdoors were directly associated with a positive change in PA level (min/week) for both genders. Higher maturation status (among boys) and later menarche were also associated with positive PA change in min/week. Predictors to remain inactive were: maternal PA change (inverse association), more exposure to outdoors, higher socio-economic level, fear of living in the neighbourhood and non-overweight girls. Predictors to become inactive were higher socio-economic level among boys and increase in screen time among girls.ConclusionsThe study demonstrates that social, family, biological, behavioural and environmental factors exert an important role in the PA change among youngsters as they move into adolescence. These findings may be relevant to the design of policies and intervention programmes aimed at promoting PA in teenagers.