bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dual frequency MIMO measurements in the 2.26–2.5 GHz band
Authors: Matthaiou Michail , Razavi‐Ghods Nima , Laurenson David I. , Salous Sana 
Published: November 2007

AbstractIn this paper, the performance of a dual Multiple‐Input Multiple‐Output (MIMO) communication system is investigated using data obtained from an indoor measurement campaign. We focus on the double‐directional channel response of each frequency band and the degree of similarity between them. In general, when a Frequency Division Duplex (FDD) system is employed, as for example in Universal Mobile Telecommunications System (UMTS), it is of vital importance to study whether the measurement results from the uplink could be directly extrapolated to the downlink direction, and vice versa. By applying two conventional beamforming techniques and the well known MUltiple SIgnal Classification (MUSIC) algorithm, the angular domain performance of both bands was assessed. The initial results presented herein are promising enough as the joint spectra seem to be remarkably similar implying that the underlying propagation mechanisms at both bands are also similar. Copyright © 2007 John Wiley & Sons, Ltd.
Energy concentration for the Landau–Lifshitz equation
Authors: Moser Roger 
Published: November 2007

For the Landau–Lifshitz equation on a domain with three space dimensions, we consider energy concentration phenomena arising in the context of weakly convergent sequences of solutions. The concentration measure can be interpreted as a family of generalized curves. We establish a connection to a geometric flow.

Résumé
Pour l'équation de Landau–Lifshitz sur un domaine en trois dimensions d'espace, nous considérons des phénomènes de concentration d'énergie survenant dans le contexte des suites faiblement convergentes de solutions. La mesure de concentration peut être interprétée comme famille de courbes généralisées. Nous établissons une connexion avec un flot géométrique.
Toward a theory of competencies for the management of product complexity: Six case studies
Authors: Closs David J. , Jacobs Mark A. , Swink Morgan , Webb G. Scott 
Published: November 2007

AbstractBusiness units in six Fortune 500 companies were studied to develop better understanding regarding drivers of product portfolio complexity and the means to manage them. Our research focuses on identifying important competencies for managing product portfolio complexity and on the development of appropriate theoretical explanations. We found three important competencies: product/technology portfolio strategy, organization and governance regarding complexity decisions, and product design and decision support systems. We explicate these competencies using a socio‐technical systems theoretical perspective. Our findings provide the basis for a model describing the impact of complexity and complexity management on business unit profitability.
Spherulites and spherulitic tactoids of anthraxolite
Authors: Dymkov Yu.M. , Yushkin N.P. , Zubov A.I. , Pavlov E.G. , Savel’ev A.S. , Filippov V.N. 
Published: November 2007

Abstract
A pebble of anthraxolite found in the basin of the Kendei River, a tributary of the Lena River, was examined under polarization metallographic and electron microscopes to get an insight into their structure and ontogeny. A polished section of the mineral demonstrates evident anisotropy in polarized reflected light and finely sculptured microrelief of growth and induction surfaces of spherulites on the fracture (fractograms). The morphogenetic inspection and study of ontogenetic signs of origination, growth, phase transformations, and other changes of anthraxolite revealed a growth mechanism typical of spherulitic dendrites owing to low-angle splitting of radial subindividuals. Layered gravity structures (‘mineralogical levels’) have been found in crystallization voids. They are composed of an ordered even-grained aggregate of spherical crystals of anthraxolite with the tactoid texture of precious opal. The tactoid mineralogical levels of anthraxolite are characterized by the block structure of microspherulite aggregates, signs of deformation, twinning and geometrical selection of blocks, and elements of recrystallization. Growth-oriented zones of regular nets with endotaxial inclusions of graphite inside the cells have been observed on induction surfaces in spherulitic dendrites. Their appearance is considered an indicator of phase transformations. Supramolecular structures and their effect on the morphology of anthraxolite are discussed in short.
Biology and field performance ofGryon clavigrallae(Hymenoptera: Scelionidae), an egg parasitoid ofClavigrallaspp. (Hemiptera: Coreidae) in India
Authors: Romeis J. , Shanower T.G. , Madhuri K. 
Published: November 2007

AbstractThe biology and impact ofGryon clavigrallaeMineo, an egg parasitoid ofClavigralla scutellarisSpinola andC. gibbosa(Westwood), was investigated. The calculated developmental threshold temperatures for females and males were 15.6°C and 15.8°C, respectively. Emergence exceeded 94% at temperatures between 22 and 30°C. Adult females lived on average 28–96 days when fed with honey. Without food, adults lived < 6 days. Mean fecundity was 56.4 eggs per female. A significant trend of lower fecundity after longer periods of host deprivation was observed.Gryon clavigrallaefemales successfully oviposited in host eggs of all ages though eggs < 4 days old were preferred. Total host handling times were significantly longer onC. gibbosaeggs (23.5 min) than onC. scutellariseggs (12.0 min). Females readily distinguished parasitized from non-parasitized host eggs. Superparasitism was observed when few or no unparasitized eggs were available. Eggs of the twoClavigrallaspecies can be separated by surface structure and condition after eclosion.Clavigralla scutellarislaid significantly larger egg clusters thanC. gibbosa(19.9 versus 10.5 eggs per cluster).Gryon clavigrallaewas present as soon as the firstClavigrallaspp. egg clusters were found on pigeonpea. The percentage of egg clusters parasitized increased early in the season with egg cluster density and remained high (up to 83%) despite fluctuations in host density. Overall,G. clavigrallaeparasitized 40 and 58% ofC. gibbosaandC. scutellariseggs. The percentage of egg clusters parasitized and the number of eggs parasitized per cluster increased significantly with egg cluster size. The overall parasitoid sex ratio was highly female biased but varied with the number of eggs parasitized per cluster.
A review of the biology and control of the coffee berry borer,Hypothenemus hampei(Coleoptera: Scolytidae)
Authors: Damon A. 
Published: November 2007

AbstractThe coffee berry borer,Hypothenemus hampeiFerrari, is a serious problem for the majority of the world‘s coffee growers and has proved to be one of the most intractable of present day pests. Despite a great deal of research, control still depends largely on the application of the organochlorine insecticide endosulfan, which is damaging to the environment, or a series of cultural and biological control methods which give variable and unpredictable results. This review summarizes the most important aspects of the biology and ecology ofH. hampeiand its control and identifies weak points in the knowledge about this pest. Emphasis is placed upon an analysis of the non-chemical control methods available and suggestions are offered for novel ecological and environmental factors worthy of further research, in the search for viable and sustainable control methods.
Stabling and the protection of horses from Culicoides bolitinos (Diptera: Ceratopogonidae), a recently identified vector of African horse sickness
Authors: Meiswinkel R. , Baylis M. , Labuschagne K. 
Published: November 2007

AbstractThe stabling of horses at night reportedly offers protection from African horse sickness and the most significant vector of the disease, Culicoides imicolaKieffer, has been shown to be exophilic. In certain high-lying regions of South Africa, however, C. bolitinos Meiswinkel, may be the major vector of the disease but its entry behaviour into stables is unknown. Accordingly, in the eastern Free State province of South Africa, light trap catches of C. bolitinos inside stables and outside, were compared. Two horse-baited stables, one traditional, and one modern, were used and combinations of stable (old/new), ceiling fans (on/off) and accessibility to Culicoides (stable doors open/closed or windows gauzed/ungauzed) were investigated as treatments. A total of 111,452 Culicoides of 26 species was collected on 60 trap nights; C. bolitinos was dominant (89.1% overall) with C. imicola second in abundance (2.9%). Outside catches were greater on warmer, drier, evenings but were suppressed by high wind speeds. Catches of C. imicola inside stables with doors open, or with windows ungauzed, were less than the numbers captured outside. In contrast, more C. bolitinos were caught in open stables than outside, i.e. open structures may protect horses from the exophilic C. imicola, but may increase attack rates from the endophilic C. bolitinos. The closing of doors and the gauzing of windows, however, led to a 14-fold reduction in numbers of C. bolitinos and C. imicola entering stables. A well-gauzed ‘traditional’ stable was as effective as a closed ‘modern’stable. Ceiling fans had no suppressant effect.
Modelling development time of Myzus persicae (Hemiptera: Aphididae) at constant and natural temperatures
Authors: Liu Shu-sheng , Meng Xue-duo 
Published: November 2007

AbstractThe development period from birth to adult of alate and apterous virginoparae of the green peach aphid, Myzus persicae (Sulzer), reared on Brassica campestrisssp. chinensis, was measured at 13 constant and five natural temperature regimes. The day–degree model, the logistic equation, and the Wang model were used to describe the relationships between temperature and development rate at constant conditions. The constant temperature–development curves derived from the three models were used with a Weibull function describing the distribution of development times, to simulate the development of individuals of cohorts reared at natural temperature regimes. Comparison of the observed with simulated distributions of adult emergence indicates that all three models can simulate the development of M. persicaevery well when the temperature does not go below 4°C, the notional low temperature threshold of the day–degree model. When accumulation of temperatures below 4°C becomes substantial, only the logistic curve with a low temperature threshold of 0°C can offer accurate simulations; the other two models give falsely longer durations of development. Methods for accurately simulating the development of M. persicae in the field are suggested. The significance of modelling insect development at low temperatures by nonlinear models is discussed.
Odour-baited targets as invasion barriers for tsetse flies (Diptera: Glossinidae): a field trial in Zimbabwe
Authors: Muzari M.O. 
Published: November 2007

AbstractIn Zimbabwe, odour-baited targets impregnated with deltamethrin were deployed at 4 km-2 in a 9 km-wide band as an invasion barrier against dense populations of Glossina morsitans morsitans Westwood and G. pallidipes Austen. Tsetse populations across the barrier were monitored by a line of traps. Invasion pressure was estimated by the catches from two additional traps about 6 km into the invasion source. After 14 months all traps more than 7 km from the invasion source recorded zero catches for 12 consecutive months, indicating that the barrier was effective in preventing re-invasion, and that the 9 km-wide barrier gave a good margin of safety.
Reduced alarm response by peach–potato aphids,Myzus persicae(Hemiptera: Aphididae), with knock-down resistance to insecticides (kdr)may impose a fitness cost through increased vulnerability to natural enemies
Authors: Foster S.P. , Woodcock C.M. , Williamson M.S. , Devonshire A.L. , Denholm I. , Thompson R. 
Published: November 2007

AbstractTermites were sampled using randomized soil pits in 64 cropping plots, each 25 x 25 m, forming an experimental agrisilvicultural system in both a 6- and an 18-year-oldTerminalia ivorensisplantation, in which canopy cover, crop, cropping system and land preparation were the principal treatment variables. The treatments were established in April 1995 and sampling was carried out in November 1995, February 1996 and July 1996. A total of 82 termite species were found, of which 67 were soil-feeders. Overall termite abundance and the abundance of soil-feeders increased between November 1995 and July 1996, reaching a mean of nearly 6000 m-2. Pooling termite data from these sampling dates, in the old plantation, the high canopy cover treatment (192 stems ha-1) had a greater abundance of termites, compared with the low canopy cover treatment (64 stems ha-1) and this effect was independent of crop type (plantain or cocoyam), cropping system (single stands or mixed crops) and land preparation (mulch retained or burned, plantain only). The young tree plantation (same tree densities as in the old plantation) showed no significant difference in termite abundance between high and low canopy (levels of tree foliage) densities, though the high canopy sheltered a greater number of termites. Analysis of covariance showed that crop yield (both plantain and cocoyam) was not directly linked to the abundance of all termite populations, but that the cocoyam yield was positively correlated with the abundance of soil-feeding termites (the majority in the assemblage) in the young plantation. This may be due to the beneficial conditioning of soil resulting from the foraging and construction activities of soil-feeders.
Linear patterns of dispersal and build up of the introduced parasitoidMicroctonus hyperodae(Hymenoptera: Braconidae) in Canterbury, New Zealand
Authors: Goldson S.L. , Proffitt J.R. , McNeill M.R. , Baird D.B. 
Published: November 2007

AbstractThe dispersal ofMicroctonus hyperodaeLoan, an introduced parasitoid of the South American grassland pestListronotus bonariensisKuschel, was measured in Canterbury, New Zealand. Considering all directions, the mean annual dispersive increment was 1.9 ± 0.9 km year–1as measured in the winters of 1993, 1994 and 1995. The parasitoid’s ground distribution suggested that its movement was biased towards the south-west indicating probable wind-borne dispersal. The overall relatively low rate of dispersal was thought to be related to the inhibitory effects ofM. hyperodaeparasitism onL. bonariensisflight. A generalized linear model fitted to percentage ofL. bonariensisparasitized took a simple form, with a quadratic increase in weevil infection, that with time, gradually decreased. The build-up of parasitism at the release site was significantly greater than the rates at the other sites measured in this study (P< 0.001) with a ratio of release site: dispersal site rates of 1.33: 1. The simplicity of the fitted generalized linear model indicated remarkable uniformity in both parasitism build-up and dispersal from one year to the next; this finding indicated that all dispersal was ‘natural’ and unassisted by human activity. Despite such modest dispersal rates, by the winter of 1996, five years after its release, the parasitoid had spread geometrically over an area ofc. 140 km2.
Molecular characterization of clones of theMyzus persicaecomplex (Hemiptera: Aphididae) differing in their ability to transmit the potato leafroll luteovirus (PLRV)
Authors: Terradot L. , Simon J.-C. , Leterme N. , Bourdin D. , Wilson A.C.C. , Gauthier J.-P. , Robert Y. 
Published: November 2007

AbstractA prerequisite to studying the specific interactions involved in the persistent transmission of luteoviruses such as the potato leafroll virus (PLRV) is the characterization of both the virus and its vectors. A range of techniques was used to assess genetic differentiation among 27 clones belonging to theMyzus persicaecomplex (M. persicae(Sulzer),M. antirrhinii(Macchiati) andM. nicotianaeBlackman) and showing different efficiencies in transmitting PLRV isolates. AllM. persicae/M. nicotianaeclones belonged to one of two karyotypes, both 2n = 12, either normal or carrying an autosomal translocation (A1,3), and allM. antirrhiniiclones had 13 or 14 chromosomes. Amplified esterase 4 genes were detected by PCR–REN assay inM. persicae/M. nicotianaetaxa, with gene expression being modified by methylation. Similarly, amplified E4 genes were revealed inM. antirrhiniibut they all showed unmethylated. Two allozyme and 11 microsatellite loci discriminated 10 different genotypic classes among the 27 clones. Analysis of genetic relatedness between these genotypic classes revealed thatM. nicotianaeclones were very closely related toM. persicaeclones, whereas the genetic differentiation betweenM. antirrhiniiandM. persicaewas greater. The implications of these results for the taxonomic status of these genotypes within the complex, and the transmission of PLRV, are discussed.
Seasonal variation in nutritional levels of male tsetse flies Glossina morsitans morsitans (Diptera: Glossinidae) caught using fly-rounds and electric screens
Authors: Van den Bossche P. , Hargrove J.W. 
Published: November 2007

AbstractA total of 4420 male Glossina morsitans morsitans Westwood were captured on man fly-rounds in Katete District, Eastern Province, Zambia between February 1991 and December 1993. Of these flies, 1680 were captured before June 1992, during which period 989 flies were also captured on odour-baited electric screens operated in the same area. Non-teneral flies were analysed for fat, haematin and residual dry weight and their wing-vein length was measured. There were well marked annual cycles in wing length, fat and residual dry weight. Flies were biggest at the end of the rainy season, and smallest at the end of the hot dry season. Fat levels were lowest before the onset of the rains and highest in the cool season. Residual dry weight was a function of haematin content and the degree of wing-fray; these factors were used to correct the residual dry weight to zero haematin. Corrected residual dry weight and wing-vein lengths were most highly correlated with relative humidity in the month prior to capture (r > 0.8 and 0.6 respectively). Correlations with saturation deficit were weaker; temperature accounted for <20% of the variance. Fly-round flies had a consistently higher residual dry weight than those from the electric screen, but their fat levels were lower. The distributions of log haematin levels differed little between the two sampling methods and were adequately described by a model where capture and feeding rates increased exponentially after each meal. The increase in the feeding rate after each meal differed little with season and was closely similar to that estimated for female G. pallidipesAusten in Zimbabwe.
Weeds and natural enemy regulation of insect pests in upland rice; a case study from West Africa
Authors: Afun J.V.K. , Johnson D.E. , Russell-Smith A. 
Published: November 2007

AbstractEffects of five weed management regimes on abundance of weeds, insect pests, generalist predators and on pest damage and rice yield were investigated in upland rice in Côte d‘Ivoire over two years. In both years there was a highly significant negative correlation between weed biomass and grain yield across all treatments. Only two pest insect groups,Nephotettixspp. (Cicadellidae) and seed sucking Heteroptera, were consistently more abundant in unweeded plots and had a consistent significant positive correlation between abundance and weed biomass across all seven treatments. These polyphagous groups may have been more dependent on resources provided by weeds than the other pests studied. However, pest damage was not affected by presence or absence of weeds, suggesting that populations were below a damage threshold. Ants were the most abundant predators in the rice canopy and were most abundant in unweeded treatments. Abundance of both ants and spiders was significantly positively correlated with weed biomass across treatments. Abundance of reduviid bugs was positively correlated with weed biomass only in 1995. Any benefits due to presence of weeds in the crop were completely outweighed by loss of crop yield due to weed competition. However, if crop losses due to weeds were sufficiently reduced, it is possible that significant losses due to insect pests might emerge.
Verification of the synonymy of Simulium damnosum cytoform ‘Nyamagasani’ with Simulium kilibanum Gouteux (Diptera: Simuliidae) together with descriptive data on related forms
Authors: Krüger A. , Garms R. 
Published: November 2007

AbstractAdults, larvae and pupae of the type material of Simulium (Edwardsellum) kilibanumGouteux from Zaïre, the important onchocerciasis vector Simulium (E.) damnosumcytoform ‘Nyamagasani’ from western Uganda and Malawi, and the closely related forms ‘Nkusi’ and ‘Sebwe’ from western Uganda were compared using morphological and molecular methods. Results support the assumption of synonymy of S. kilibanum and the cytoform ‘Nyamagasani’, which hitherto was based on weak evidence. The description of S. kilibanumis supplemented and detailed descriptive data are given of ‘Nyamagasani’and the cytoforms ‘Nkusi’ and ‘Sebwe’ all of which are taxa of the ‘Sanje’ group of the S. damnosum complex.
Textile systems and one-sided resolving automorphisms and endomorphisms of the shift
Authors: NASU MASAKAZU 
Published: November 2007

AbstractTwo results on textile systems are obtained. Using these we prove that for any automorphism φ of any topologically-transitive subshift of finite type, if φ is expansive and φ or φ−1 has memory zero or anticipation zero, then φ is topologically conjugate to a subshift of finite type. Moreover, this is generalized to a result on chain recurrent onto endomorphisms of topologically-transitive subshifts of finite type. Using textile systems and textile subsystems, we develop a structure theory concerning expansiveness with the pseudo orbit tracing property on directionally essentially weakly one-sided resolving automorphisms and endomorphisms of subshifts.