bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioactivity of compounds from Acmella oleracea against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and selectivity to two non‐target species
Authors: Moreno Shaiene C , Carvalho Geraldo A , Picanço Marcelo C , Morais Elisangela GF , Pereira Rogério M 
Published: September 2011

AbstractBACKGROUND: Tropical plants are recognised sources of bioactive compounds that can be used for pest control. The objective of this study was to evaluate the biological activity of compounds present in Acmella oleracea (Asteracea) against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), which is the main pest of tomato crops in Latin America. The selectivity of these compounds to the predator Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) and to the pollinator Tetragonisca angustula (Latr.) (Hymenoptera: Apidae: Meliponinae) was also of interest.RESULTS: A bioassay screening with hexane and ethanol extracts from 23 plants was performed. The hexane extract of A. oleraceae was the most active of the extracts and was selected for further study. The following three alkamides were isolated from a hexane extract of the aerial parts of A. oleracea: spilanthol, (E)‐N‐isobutylundeca‐2‐en‐8,10‐diynamide and (R, E)‐N‐(2‐methylbutyl)undeca‐2‐en‐8,10‐diynamide. All of the isolated compounds showed insecticidal activity, with spilanthol being the most active (LD50 = 0.13 µg mg−1) against T. absoluta. The alkamides were selective to both beneficial species studied.CONCLUSION: The crude hexane extract of A. oleraceae showed high insecticidal activity and can be used to control T. absoluta in organic or conventional crops. Quantification of LD50 values of isolated compounds against T. absoluta showed that alkamides could serve as potent insecticides for T. absoluta control programmes. Spilanthol was the main alkamide active isolated. This alkamide is the most promising as it has the highest insecticidal activity and is selective to non‐target organisms. Copyright © 2011 Society of Chemical Industry
Glyphosate resistance in perennial Sorghum halepense (Johnsongrass), endowed by reduced glyphosate translocation and leaf uptake
Authors: Vila‐Aiub Martin M , Balbi María C , Distéfano Ana J , Fernández Luis , Hopp Esteban , Yu Qin , Powles Stephen B 
Published: September 2011

AbstractBACKGROUND: In a large cropping area of northern Argentina, Sorghum halepense (Johnsongrass) has evolved towards glyphosate resistance. This study aimed to determine the molecular and biochemical basis conferring glyphosate resistance in this species. Experiments were conducted to assess target EPSPS gene sequences and 14C‐glyphosate leaf absorption and translocation to meristematic tissues.RESULTS: Individuals of all resistant (R) accessions exhibited significantly less glyphosate translocation to root (11% versus 29%) and stem (9% versus 26%) meristems when compared with susceptible (S) plants. A notably higher proportion of the applied glyphosate remained in the treated leaves of R plants (63%) than in the treated leaves of S plants (27%). In addition, individuals of S. halepense accession R2 consistently showed lower glyphosate absorption rates in both adaxial (10–20%) and abaxial (20–25%) leaf surfaces compared with S plants. No glyphosate resistance endowing mutations in the EPSPS gene at Pro‐101–106 residues were found in any of the evaluated R accessions.CONCLUSION: The results of the present investigation indicate that reduced glyphosate translocation to meristems is the primary mechanism endowing glyphosate resistance in S. halepense from cropping fields in Argentina. To a lesser extent, reduced glyphosate leaf uptake has also been shown to be involved in glyphosate‐resistant S. halepense. Copyright © 2011 Society of Chemical Industry
Morphological, optical, and Raman characteristics of ZnO nanoflakes prepared via a sol–gel method
Authors: Kashif M. , Usman Ali Syed M. , Ali M. E. , Abdulgafour H. I. , Hashim U. , Willander M. , Hassan Z. 
Published: September 2011

AbstractTwo‐dimensional (2D) ZnO nanoflakes were grown on thin aluminum layer, deposited on silicon substrate, using a sol–gel method. The surface morphologies of ZnO nanoflakes at different precursor concentrations were studied using scanning electron microscopy (SEM). Combined studies of SEM, photoluminescence (PL), and Raman spectroscopy suggested that nanorods started to grow along with nanoflakes at a precursor concentration of 0.05 M and the density of the nanorods significantly increased when the concentration was raised to 0.075 M. Both the UV‐luminescence and Raman spectra were intensified and redshifted with the increment of precursor concentration. Spectral intensification suggests improvement in crystal qualities and better optical properties of the fabricated ZnO nanostructures. The structural defects at lower levels of precursor were probably due to the hypoxic environment, whereas, the redshift of PL and Raman spectra was due to the local heating of ZnO nanocrystals.
Consensus for multi‐agent systems under double integrator dynamics with time‐varying communication delays
Authors: Liu Kaien , Xie Guangming , Wang Long 
Published: September 2011

SUMMARYIn this paper, the consensus control problems for multi‐agent systems under double integrator dynamics with time‐varying communication delays are investigated. We assume that the interaction graphs among agents are directed. Two kinds of protocols are considered. One is an absolute damping protocol, and the other is a relative damping protocol. For the first protocol, Lyapunov–Razumikhin functional techniques are used. We derive sufficient conditions that guarantee that all agents asymptotically reach consensus under fixed topology and switching topology, respectively. Moreover, the allowable upper bound for communication delays is given. For the second protocol, Lyapunov–Krasovskii functional techniques are used. Linear matrix inequality (LMI)‐form sufficient conditions are obtained to guarantee the consensus problems to be solved under fixed topology and switching topology, respectively. The allowable upper bound for communication delays is given as well. The feasibilities of the demanded LMIs are also discussed. Finally, numerical simulations are provided to illustrate the effectiveness of our theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.
Active fault‐tolerant control of sampled‐data nonlinear distributed parameter systems
Authors: Ghantasala Sathyendra , El‐Farra Nael H. 
Published: September 2011

SUMMARYThis work presents an integrated fault detection and fault‐tolerant control architecture for spatially distributed systems described by highly dissipative systems of nonlinear partial differential equations with actuator faults and sampled measurements. The architecture consists of a family of nonlinear feedback controllers, observer‐based fault detection filters that account for the discrete measurement sampling, and a switching law that reconfigures the control actuators following fault detection. An approximate finite‐dimensional model that captures the dominant dynamics of the infinite‐dimensional system is embedded in the control system to provide the controller and fault detection filter with estimates of the measured output between sampling instances. The model state is then updated using the actual measurements whenever they become available from the sensors. By analyzing the behavior of the estimation error between sampling times and exploiting the stability properties of the compensated model, a sufficient condition for the stability of the sampled‐data nonlinear closed‐loop system is derived in terms of the sampling rate, the model accuracy, the controller design parameters, and the spatial placement of the control actuators. This characterization is used as the basis for deriving appropriate rules for fault detection and actuator reconfiguration. Singular perturbation techniques are used to analyze the implementation of the developed architecture on the infinite‐dimensional system. The results are demonstrated through an application to the problem of stabilizing the zero solution of the Kuramoto–Sivashinsky equation. Copyright © 2011 John Wiley & Sons, Ltd.
In the mood for entrepreneurial creativity? How optimal group affect differs for generating and selecting ideas for new ventures
Authors: Perry‐Smith Jill E. , Coff Russell W. 
Published: September 2011

AbstractSuperior entrepreneurial creativity arises when teams are effective at both generating diverse alternatives and culling them to select the best solution. We develop theory about how the optimal group mood varies for the generation and selection stages of creativity. Using data from an entrepreneurial creativity task, we find that these stages require distinct collective moods. While an activated‐pleasant mood promotes variance generation, idea selection requires a very different mood. Findings suggest that some teams fail to make transitions to the appropriate mood. We conclude by discussing implications for promoting entrepreneurial creativity. Copyright © 2011 Strategic Management Society.
Longitudinal factorial invariance of the Maslach Burnout Inventory‐General Survey among employees with job‐related psychological health problems
Authors: Mäkikangas Anne , Hätinen Marja , Kinnunen Ulla , Pekkonen Mika 
Published: September 2011

AbstractThe study provides new knowledge about the longitudinal factorial invariance of the Maslach Burnout Inventory‐General Survey (MBI‐GS). In order to investigate the factor structure of the MBI‐GS and its invariance across time, a full panel data with two measurements gathered among employees with job‐related psychological health problems was used. Consistent with previous study findings, the results indicated that the correlated three‐factor model of the MBI‐GS (i.e. exhaustion, cynicism and professional efficacy) showed a better fit with the data than the alternative factor models. The correlated three‐factor structure was invariant across time, indicating that the scale has good construct validity, thus producing evidence that the MBI‐GS is a valid scale to measure job burnout. The novel finding of the study was that the professional efficacy dimension was a more central symptom of the burnout syndrome than previous research evidence among healthy employees has established. Copyright © 2011 John Wiley & Sons, Ltd.
Physical Vapor Deposition of Metal Nanoparticles on Chemically Modified Graphene: Observations on Metal–Graphene Interactions
Authors: Pandey Priyanka A. , Bell Gavin R. , Rourke Jonathan P. , Sanchez Ana M. , Elkin Mark D. , Hickey Bryan J. , Wilson Neil R. 
Published: September 2011

AbstractThe growth of metallic nanoparticles formed on chemically modified graphene (CMG) by physical vapor deposition is investigated. Fine control over the size (down to ∼1.5 nm for Au) and coverage (up to 5 × 104 μm−2 for Au) of nanoparticles can be achieved. Analysis of the particle size distributions gives evidence for Au nanocluster diffusion at room temperature, while particle size statistics differ clearly between metal deposited on single‐ and multilayer regions. The morphology of the nanoparticles varies markedly for different metals (Ag, Au, Fe, Pd, Pt, Ti), from a uniform thin film for Ti to a droplet‐like growth for Ag. A simple model explains these morphologies, based only on consideration of 1) the different energy barriers to surface diffusion of metal adatoms on graphene, and 2) the ratio of the bulk cohesive energy of the metal to the metal–graphene binding energy. Understanding these interactions is important for controlling nanoparticle and thin‐film growth on graphene, and for understanding the resultant charge transfer between metal and graphene.
Defining a catalog of indicators to support process performance analysis
Authors: Monteiro Luis Felipe Salin , de Oliveira Kathia Marçal 
Published: September 2011

AbstractTo achieve high‐level maturity in software process improvement, organizations must change the project management focus from the empirical assessment of process performance to quantitative management of the software process based on performance measures and statistical techniques. To this purpose, managers need to work with years of measurement data to establish control limits and conduct performance analyses. In this context, some difficulties are encountered: Which measures should be used, considering that early definition is important? Which statistical technique is more adequate in each case? How should we work with the data? We found more than 500 different measures in the literature applicable to software process performance and a number of different statistical techniques to analyze and choose from. This article aims at defining a catalog of indicators with their related measures in answer to the above questions, in a way that can help managers perform process performance analysis of the Capability Maturity Model Integration for Development (CMMI‐DEV) engineering processes. This article presents how we define and use this catalog and the complete specification of two indicators. Copyright © 2009 John Wiley & Sons, Ltd.
Application of adaptive neuro‐fuzzy inference for wind power short‐term forecasting
Authors: Pousinho Hugo M. I. , Mendes Victor M. F. , Catalão João P. S. 
Published: September 2011

AbstractThe increased integration of wind power into the electric grid, as nowadays occurs in Portugal, poses new challenges due to its intermittency and volatility. Hence, good forecasting tools play a key role in tackling these challenges. In this paper, an adaptive neuro‐fuzzy inference approach is proposed for short‐term wind power forecasting. Results from a real‐world case study are presented. A thorough comparison is carried out, taking into account the results obtained with other approaches. Numerical results are presented and conclusions are duly drawn. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Performance analysis of geography‐limited broadcasting in multihop wireless networks
Authors: Chen Quanjun , Kanhere Salil S. , Hassan Mahbub 
Published: September 2011

ABSTRACTIn multihop wireless networks, delivering a packet to all nodes within a specified geographic distance from the source is a packet forwarding primitive (geography‐limited broadcasting), which has a wide range of applications including disaster recovery, environment monitoring, intelligent transportation, battlefield communications, and location‐based services. Geography‐limited broadcasting, however, relies on all nodes having continuous access to precise location information, which may not be always achievable. In this paper, we consider achieving geography‐limited broadcasting by means of the time‐to‐live (TTL) forwarding, which limits the propagation of a packet within a specified number of hops from the source. Because TTL operation does not require location information, it can be used universally under all conditions. Our analytical results, which are validated by simulations, confirm that TTL‐based forwarding can match the performance of the traditional location‐based geography‐limited broadcasting in terms of the area coverage as well as the broadcasting overhead. It is shown that the TTL‐based approach provides a practical trade‐off between geographic coverage and broadcast overhead. By not delivering the packet to a tiny fraction of the total node population, all of which are located near the boundary of the target area, TTL‐based approach reduces the broadcast overhead significantly. This coverage‐overhead trade‐off is useful if the significance of packet delivery reduces proportionally to the distance from the source. Copyright © 2011 John Wiley & Sons, Ltd.
Performance analysis and power allocation for decode‐and‐forward cooperative communications over Rician fading channel
Authors: Chu Shao‐I , Lin Wei‐Cheng , Lee Hung‐Peng , Chang Hsin‐Chiu 
Published: September 2011

ABSTRACTThis paper derives the asymptotic symbol error rate (SER) and outage probability of decode‐and‐forward (DF) cooperative communications over Rician fading channels. How to optimally allocate the total power is also addressed when the performance metric in terms of SER or outage probability is taken into consideration. Analysis reveals the insights that Rician factor has a great impact on the system performance as compared with the channel variance, and the relay–destination channel quality is of importance. In addition, the source–relay channel condition is irrelevant to the optimal power allocation design. Simulation and numerical evaluation substantiate the tightness of the asymptotic expressions in the high‐SNR regions and demonstrate the accuracy of our theoretical analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Warning signs mitigate deer–vehicle collisions in an Urban area
Authors: Found Rob , Boyce Mark S. 
Published: September 2011

AbstractIncreasing collisions with deer (Odocoileus spp.) and other large animals, and the rise in associated public safety risks and economic costs, have made mitigation strategies a priority for both transportation and wildlife managers. Deer‐crossing warning signage is one of the oldest forms of mitigating deer–vehicle collisions (DVCs), but despite their low cost and logistical simplicity, the effectiveness of standard‐sized permanent warning signage at reducing DVCs has not previously been adequately determined. We used historical DVC data, based on deer carcass retrieval, to identify and target areas and periods of high collision frequency. We installed warning signs at these high collision frequency locations and then compared DVCs to un‐signed control locations. The total number of DVCs at signed hotspots was significantly different in the year after the signs were installed, compared to the 3 prior years (F13 = 4.99, P = 0.004). Although the single year of posttreatment data means the long‐term efficacy of warning signage remains unknown, we showed that in the first year after installation, deer‐crossing signs targeting high collision locations can be effective at reducing DVCs. © 2011 The Wildlife Society.
Effects of human activity on space use and movement patterns of female Elk
Authors: Webb Stephen L. , Dzialak Matthew R. , Harju Seth M. , Hayden‐Wing Larry D. , Winstead Jeffrey B. 
Published: September 2011

AbstractIt is important to consider how human activity might influence behavior (e.g., space use and movement) in animals because such influences could have consequences for animal distribution or population performance. We documented and compared annual space use and daily movement patterns (i.e., movement distance and tortuosity) of female elk (Cervus elaphus) relative to human activity associated with development of energy resources in Colorado and New Mexico, USA, from 2006 to 2010. We analyzed data on 145 female elk fitted with global positioning system collars. While controlling for elevation, slope, and distance to anthropogenic features and vegetative cover, we found that proximity to the gas field generally was associated with smaller home ranges, more complex movement paths (i.e., greater tortuosity) and longer distance moved over a 3‐hr period (during most seasons). Comparing elk inside of the gas field to those outside of the gas field revealed differences in space use and movement patterns at varying levels of human activity. These differences likely reflected behavior by which elk in industrial areas attempted to minimize contact with sources of human activity; whereas, elk using both industrial and nonindustrial areas exhibited behavior that could be considered escape strategies (i.e., familiarity and use of large spatial extents, increased movement distance, and linear movement paths) in response to seemingly unpredictable levels of human activity due to their use of multiple areas. Understanding such behavioral responses informs efforts to minimize effects of human activity on animal populations. © 2011 The Wildlife Society.
Influence of underpasses and traffic on white‐tailed deer highway permeability
Authors: Dodd Norris L. , Gagnon Jeffrey W. 
Published: September 2011

AbstractHighways constitute barriers to wildlife passage, or permeability, which fragment populations and habitats. The degree of barrier effect caused by roadways varies by wildlife species, highway type and standard, and traffic volume. We assessed deer–highway relationships along a 27‐km stretch of highway in central Arizona, USA. Our research objectives were to 1) assess white‐tailed deer (Odocoileus virginianus) highway crossing patterns and permeability, 2) compare deer permeability on 4‐lane reconstructed and 2‐lane control sections to determine the influence of wildlife underpasses, and 3) assess and compare deer passage relationships to traffic volume. We fitted 13 deer with Global Positioning System (GPS) collars between 2004 and 2007. Eleven deer crossed the highway 395 times. On 2 control sections, deer crossed an average of 0.02 times/day, while on 3 reconstructed sections they averaged 15 times more crossings/day (0.28; t13 = −2.35; P = 0.035). The deer passage rate on control sections averaged 0.03 crossings/approach, approximately 20% of that for reconstructed sections (0.16; t13 = −2.43; P = 0.030). We linked hourly traffic volumes to our GPS data to examine how passage rates and the proportion of deer relocations at different distances from the highway varied with traffic volume. Deer distance from the highway showed minimal shift away from the highway with increased traffic, and at‐grade passage rates were low (≤0.1 crossings/approach) across all traffic volumes. Although our linear regression analysis found no relationship between deer passage rate and increasing traffic volume on reconstructed sections with underpasses, there was a strong negative relationship on control sections (r = −0.881; P = 0.05); thus, we conclude that deer passage rates were minimally affected by traffic on reconstructed sections where passage structures facilitated below‐grade passage. Further, from the 865 deer groups we recorded on videotape at 5 underpasses, traffic levels did not affect below‐grade deer passage at the volumes we studied. Passage structures improved highway permeability across reconstructed sections with underpasses where traffic volume had a much lower impact compared to deer crossing at highway grade on control sections. © 2011 The Wildlife Society.