bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of spatial disturbance on common loon nest site selection and territory success
Authors: Mccarthy Kyle P. , Destefano Stephen 
Published: March 2011

AbstractThe common loon (Gavia immer) breeds during the summer on northern lakes and water bodies that are also often desirable areas for aquatic recreation and human habitation. In northern New England, we assessed how the spatial nature of disturbance affects common loon nest site selection and territory success. We found through classification and regression analysis that distance to and density of disturbance factors can be used to classify observed nest site locations versus random points, suggesting that these factors affect loon nest site selection (model 1: Correct classification = 75%, null = 50%,K = 0.507,P < 0.001; model 2: Correct classification = 78%, null = 50%,K = 0.551,P < 0.001). However, in an exploratory analysis, we were unable to show a relation between spatial disturbance variables and breeding success (P = 0.595,R2 = 0.436), possibly because breeding success was so low during the breeding seasons of 2007–2008. We suggest that by selecting nest site locations that avoid disturbance factors, loons thereby limit the effect that disturbance will have on their breeding success. Still, disturbance may force loons to use sub‐optimal nesting habitat, limiting the available number of territories, and overall productivity. We advise that management efforts focus on limiting disturbance factors to allow breeding pairs access to the best nesting territories, relieving disturbance pressures that may force sub‐optimal nest placement. © 2011 The Wildlife Society
A population model to simulate northern bobwhite population dynamics in southern Texas
Authors: DeMaso Stephen J. , Grant William E. , Hernández Fidel , Brennan Leonard A. , Silvy Nova J. , Wu X. Ben , Bryant Fred C. 
Published: March 2011

AbstractModels are important tools that can help managers and researchers understand the population dynamics of a species and how different habitat or population management scenarios impact that species. We used radio‐telemetry data from northern bobwhites (Colinus virginianus) in southern Texas from 2000 to 2005 to develop a stochastic simulation model for bobwhite populations. Our model is based on difference equations, with stochastic variables drawn from normal and Weibull distributions. We simulated bobwhite populations to 100 yr and evaluated our model by comparing results with independent estimates of 4 population parameters (spring and fall density, finite rate of increase in the fall population [λ], and winter juv:ad age ratios). Using a quasi‐extinction criterion of ≤40 birds (density = ≤0.05 birds/ha), probability of persistence to 100 yr was 88.3% (106 of 120 simulations) for the spring population and 96.7% (116 of 120 simulations) for the fall population. Using a less restrictive quasi‐extinction criteria (≤14 birds), probability of persistence was 93.3% (112 of 120 simulations) for the spring population and 98.3% (118 of 120 simulations) for the fall population. Simulated population parameters were similar to independent estimates for 4 of 4 population parameters. Winter age ratios differed between our model ($\overline {x} = 4.98$juv:ad,n = 120, SE = 0.32) and empirical age ratios from harvested bobwhites on our study area ($\overline {x} = 2.85$juv:ad,n = 25, SE = 0.24). However, when we corrected harvest age ratios for bias in juvenile harvest ($\overline {x} = 3.85$juv:ad,n = 25, SE = 0.32) simulated and empirical estimates were similar. Our model appears to be a reliable predictor of bobwhite populations in the southern Texas. Our simulation results indicate that bobwhite hunters and managers can expect excellent bobwhite hunting (fall populations ≥2.2 birds per ha) in about one of 10 yr. © 2011 The Wildlife Society
Bias associated with baited camera sites for assessing population characteristics of deer
Authors: Mccoy J. Clint , Ditchkoff Stephen S. , Steury Todd D. 
Published: March 2011

AbstractCamera surveys often involve placing bait in front of the camera to capture animals more frequently, which could introduce biases in parameter estimates. From September 2008 to March 2009, we monitored cameras placed at random, along game trails, and at feed stations to determine if camera placement influenced measures of population demographics in a herd of white‐tailed deer (Odocoileus virginianus). There was no time period in which cameras placed at feed stations provided sex ratio and recruitment estimates similar to those acquired from randomly placed cameras. Trail‐based camera surveys provided population estimates similar to those from random sites and may provide a feasible alternative to using baited camera stations. © 2011 The Wildlife Society.
Effect of great‐horned owl trapping on chick survival in piping plovers
Authors: Catlin Daniel H. , Felio Joy H. , Fraser James D. 
Published: March 2011

AbstractWe studied the effect of great‐horned owl (Bubo virginianus) removal on piping plover (Charadrius melodus) hatchling survival on Missouri River sandbars (2008–2009). Owl removal increased daily survival of piping plover chicks in 2008 (β = 2.03, 95% CI: 0.04–4.02), but this effect decreased with increasing age of the chick (β = −0.42, 95% CI: −0.81 to −0.03). Results for 2009 were similar in direction but not significant. Survival was higher in 2008 than in 2009, regardless of owl capture, indicating that even if owl capture consistently were effective at increasing survival, overall survival resulting from trapping may vary annually. Owl trapping was a successful means to raise chick survival on the Missouri River in ≥1 year and could be used at other sites experiencing depressed chick survival due to avian predators. © 2011 The Wildlife Society.
Habitat selection by mountain plovers in shortgrass steppe
Authors: Augustine David J. 
Published: March 2011

AbstractMuch of the breeding range for the mountain plover (Charadrius montanus) occurs in shortgrass steppe and mixed‐grass prairie in the western Great Plains of North America. Studies of mountain plovers in shortgrass steppe during the 1970s and 1990s were focused in Weld County, Colorado, which was considered a key breeding area for the species. These studies, however, did not include habitats influenced by black‐tailed prairie dogs (Cynomys ludovicianus) or prescribed fire. The role of these 2 rangeland disturbance processes has increased substantially over the past 15 years. During 2008–2009, I used radial distance point count surveys to estimate mountain plover densities early in the nesting season in 4 habitats on public lands in Weld County, Colorado. All 4 habitats were grazed by cattle during the growing season at moderate stocking rates but had different additional disturbances consisting of 1) dormant‐season prescribed burns, 2) active black‐tailed prairie dog colonies, 3) black‐tailed prairie dog colonies affected by epizootic plague in the past 1–2 years, and 4) rangeland with no recent history of fire or prairie dogs. Mountain plover densities were similar on active black‐tailed prairie dog colonies (${\rm {\bar {X}}}$ = 6.8 birds/km2, 95% CI = 4.3–10.6) and prescribed burns (${\rm {\bar {X}}}$ = 5.6 birds/km2, 95% CI = 3.5–9.1). In contrast, no plovers were detected at randomly selected rangeland sites grazed by cattle but lacking recent disturbance by prairie dogs or fire, even though survey effort was highest for this rangeland habitat. Mountain plover densities were intermediate (2.0 birds/km2, 95% CI = 0.8–5.0) on sites where black‐tailed prairie dogs had recently been extirpated by plague. These findings suggest that prescribed burns and active black‐tailed prairie dog colonies may enhance breeding habitat for mountain plovers in shortgrass steppe and illustrate the potential for suppressed or altered disturbance processes to influence habitat availability for declining wildlife species. © 2011 The Wildlife Society.
Development of kinetic models for acid‐catalyzed methyl acetate formation reaction: Effect of catalyst concentration and water inhibition
Authors: Ganesh B. , Rani K. Yamuna , Satyavathi B. , Venkateswarlu Ch. 
Published: March 2011

AbstractThe reaction kinetics of reversible liquid‐phase esterification of acetic acid with methanol is investigated in the temperature range 26–50°C using sulfuric acid catalyst. The main goal of this work is to study the effect of catalyst concentration and sensitivity to the presence of water on the rate expression of this industrially important reaction. Experiments are conducted in an isothermal batch reactor and a second‐order kinetic model is used to correlate the experimental data, which are found to fit well with the assumed kinetic model in terms of the concentrations of reactants and products. Furthermore, an activity‐based kinetic model is also developed employing the UNIQUAC (universal quasi‐chemical equation) model to compute the activities. It is observed that the rate constant is influenced by the concentration of catalyst, and the reaction rate increased with an increase in the catalyst concentration. It is also observed that the catalyst activity is slightly inhibited by the water present in the reaction mixture. The performance of the proposed models is compared with that of other models reported in the literature, and it is found that the proposed models outperformed all the other models reported in the literature. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 263–277, 2011
Science for improving the monitoring and assessment of dryland degradation
Authors: Winslow M. D. , Vogt J. V. , Thomas R. J. , Sommer S. , Martius C. , Akhtar‐Schuster M. 
Published: March 2011

AbstractThe United Nations Convention to Combat Desertification (UNCCD) commissioned its First Scientific Conference in 2009 to deliberate on ways to improve the global monitoring and assessment of dryland degradation to support decision‐making in land and water management. The papers included in this issue of Land Degradation & Development elaborate the reasoning behind the 11 recommendations that emerged from the Conference and were formally submitted to the UNCCD. These papers argue for a more holistic, harmonised and integrated approach to dryland monitoring and assessment, and describe scientific and institutional approaches for achieving this goal. A central challenge is to integrate human/social with environmental observations in accordance with the Convention's view that the interactions and tradeoffs between human development needs and land condition must be considered. A global monitoring and assessment regime should be established to gather and analyse relevant data on a routine basis, allowing locally‐relevant indicators to be aggregated into meaningful classes appropriate to different decision‐making levels. The underlying forces that cause changes in land condition should also be monitored and assessed so that remedial actions can target the true causes of dryland degradation, including social, economic, policy, institutional and knowledge drivers that have often been overlooked in the past. Monitoring and assessment should hybridise differing types of knowledge generated by different stakeholders in order to strengthen collective capacities to combat dryland degradation. An independent scientific advisory mechanism should be created to advise the UNCCD about the results emerging from the monitoring and assessment regime in order to improve decision‐making. Copyright © 2011 John Wiley & Sons, Ltd.
Porphyrin–Polymer Networks, Worms, and Nanorods: pH‐triggerable Hierarchical Self‐assembly
Authors: Ruthard Christian , Schmidt Manfred , Gröhn Franziska 
Published: March 2011

AbstractIn this study, we present a novel, multifaceted pH‐triggerable system of self‐organized hierarchical nanostructures. The system consists of meso‐tetrakis(4‐sulfonatophenyl)porphyrin (TPPS) and poly(2‐vinylpyridine) cylindrical brushes (PVP brushes) and can yield polymer–porphyrin networks, porphyrin loaded polymer brushes and pure porphyrin nanorods. In addition, the polymer influences the pKa and the mutual TPPS stacking geometry. Structures were characterized by AFM, dynamic light scattering using an IR laser, UV–Vis spectroscopy and small‐angle neutron scattering (SANS). Supramolecular composite porphyrin structures that can be switched through external triggers have potential in photodynamic tumor therapy (PDT) and for nanoelectronics. magnified image
Guaiane‐type sesquiterpenoid glucosides from Gardenia jasminoides Ellis
Authors: Yu Yang , Gao Hao , Dai Yi , Xiao Gao‐Keng , Zhu Hua‐Jie , Yao Xin‐Sheng 
Published: March 2011

AbstractTwo new guaiane‐type sesquiterpenoid glucosides (1 and 2) were isolated from the fruit of Gardenia jasminoides Ellis. Their structures were elucidated to be (1R,7R,10S)‐11‐O‐β‐D‐glucopyranosyl‐4‐guaien‐3‐one (1) and (1R,7R,10S)‐7‐hydroxy‐11‐O‐β‐D‐glucopyranosyl‐4‐guaien‐3‐one (2) by one‐ and two‐dimensional NMR techniques (1H NMR, 13C NMR, HSQC, HMBC and NOESY), MS, CD spectrometry and chemical methods. Copyright © 2011 John Wiley & Sons, Ltd.
1H, 13C, 15N NMR coordination shifts in Fe(II), Ru(II) and Os(II) cationic complexes with 2,2′:6′,2″‐terpyridine
Authors: Pazderski Leszek , Pawlak Tomasz , Sitkowski Jerzy , Kozerski Lech , Szlyk Edward 
Published: March 2011

Abstract1H, 13C and 15N NMR studies of iron(II), ruthenium(II) and osmium(II) bis‐chelated cationic complexes with 2,2′:6′,2″‐terpyridine ([M(terpy)2]2+; M = Fe, Ru, Os) were performed. Significant shielding of nitrogen‐adjacent H(6) and deshielding of H(3′), H(4′) protons were observed, both effects being mostly expressed for Fe(II) compounds. The metal‐bonded nitrogens were shielded, this effect being much larger for the outer N(1), N(1″) than the inner N(1′) atoms, and enhanced in the Fe(II) → Ru(II) → Os(II) series. Copyright © 2011 John Wiley & Sons, Ltd.
Complete 13C NMR assignments for ent‐kaurane diterpenoids from Sideritis species
Authors: Halfon Belkıs , Ceyhan Gören Ahmet , Ertaş Abdülselam , Topçu Gülaçtı 
Published: March 2011

AbstractIn this work, the detailed NMR studies and full 13C NMR assignments for five diterpenoids isolated from Sideritis caesarea and Sideritis athoa are described. The assignments are based on a combination of 1D and 2D NMR techniques including 1H, 13C, 1H1H COSY, gHSQC [1J(C,H)] and gHMBCδC [nJ(C,H) (n = 2 and 3)] and NOESY experiments. Copyright © 2011 John Wiley & Sons, Ltd.
Molecular cloning and expression analysis of the Mitogen‐activating protein kinase 1 (MAPK1) gene and protein during ovarian development of the giant tiger shrimp Penaeus monodon
Authors: Ponza Pattareeya , Yocawibun Patchari , Sittikankaew Kanchana , Hiransuchalert Rachanimuk , Yamano Keisuke , Klinbunga Sirawut 
Published: March 2011

AbstractIsolation and characterization of genes and/or proteins differentially expressed in ovaries are necessary for understanding ovarian development in the giant tiger shrimp (Penaeus monodon). In this study, the full‐length cDNA of P. monodon mitogen‐activating protein kinase 1 (PmMAPK1) was characterized. PmMAPK1 was 1,398 bp in length containing an open reading frame of 1,098 bp that corresponded to a polypeptide of 365 amino acids. PmMAPK1 was more abundantly expressed in ovaries than in testes of P. monodon. Quantitative real‐time PCR revealed differential expression levels of PmMAPK1 mRNA during ovarian development of intact broodstock, where it peaked in early cortical rod (stage III) ovaries (P < 0.05) and slightly decreased afterwards (P > 0.05). Likewise, the expression level of PmMAPK1 in early cortical rod and mature (IV) ovaries was significantly greater than that in previtellogenic (I) and vitellogenic (II) ovaries of eyestalk‐ablated broodstock (P < 0.05). The PmMAPK1 transcript was localized in ooplasm of previtellogenic oocytes. In intact broodstock, the expression of the PmMAPK1 protein was clearly increased from previtellogenic ovaries in subsequent stages of ovarian development (P < 0.05). In contrast, the level of ovarian PmMAPK1 protein was comparable during oogenesis in eyestalk‐ablated broodstock (P > 0.05). The PmMAPK1 protein was localized in ooplasm of previtellogenic and vitellogenic oocytes. It was also detected around the nuclear membrane of early cortical rod oocytes in both intact and eyestalk‐ablated broodstock. Results indicated that PmMAPK1 gene products seem to play functional roles in the development and maturation of oocytes/ovaries in P. monodon. Mol. Reprod. Dev. 78:347–360, 2011. © 2011 Wiley‐Liss, Inc.
Activation of cumulus cell SMAD2/3 and epidermal growth factor receptor pathways are involved in porcine oocyte–cumulus cell expansion and steroidogenesis
Authors: Nagyova Eva , Camaioni Antonella , Scsukova Sona , Mlynarcikova Alzbeta , Prochazka Radek , Nemcova Lucie , Salustri Antonietta 
Published: March 2011

AbstractSeveral lines of evidence suggest that in mice the activation of SMAD2/3 signaling by oocyte secreted factors, together with epidermal growth factor receptor (EGFR) activation, is essential to induce cumulus expansion. Here we show that inhibition of EGFR kinase in follicle stimulating hormone (FSH)‐stimulated porcine oocyte–cumulus cell complex (OCCs) strongly decreases hyaluronan (HA) synthesis and its retention in the matrix, as well as progesterone synthesis. Although porcine cumulus cells undergo expansion independently of oocytes, we use biochemical and gene expression analyses to show that they do require activation of SMAD2/3 for optimal stimulation of HA synthesis and proteins involved in the organization of this polymer in the expanded matrix. Furthermore, FSH‐induced progesterone synthesis by porcine cumulus cells was increased by blocking SMAD2/3 activation. In conclusion, these results support the hypothesis that an FSH–EGF autocrine loop is active in porcine OCCs, and provide the first evidence that the SMAD2/3 signaling pathway is induced by paracrine/autocrine factors in porcine cumulus cells and is involved in the control of both cumulus expansion and steroidogenesis. Mol. Reprod. Dev. 78:391–402, 2011. © 2011 Wiley‐Liss, Inc.
Cost reduction techniques for the design of non‐linear flapping wing structures
Authors: Stanford Bret K. , Beran Philip S. 
Published: March 2011

AbstractThis work details a computational framework for gradient‐based optimization of a non‐linear flapping wing structure with a large number of design variables, where analytical sensitivities of the unsteady finite element system are computed using the adjoint method. Two techniques are used to reduce the large computational cost of this structural design process. The first projects the finite element system onto a reduced basis of POD modes. The second uses a monolithic time formulation with spectral elements, and can be used to compute only the desired time‐periodic response. Results are given in terms of the trade‐off between accuracy and computational efficiency of these methods for both system response and adjoint computations, for a variety of mesh/time step refinements, degrees of non‐linearity (i.e. weakly or strongly non‐linear), and harmonic content. The work concludes with the structural design of a flapping wing: the elastic deformation at the wingtip is minimized through the flapping stroke by varying the thickness of each finite element. Significant improvements in computational cost are obtained at little expense to the accuracy of the results obtained via design optimization. Published in 2011 by John Wiley & Sons, Ltd.
Comparison of solution strategies for multibody dynamics equations
Authors: Mariti L. , Belfiore N. P. , Pennestrì E. , Valentini P. P. 
Published: March 2011

AbstractIn the last decades, several different formalisms have been proposed in the literature in order to simulate the dynamics of multibody systems. First, the choice of the coordinates leads to very different formalisms. The set of constraint equations appears very different in complexity or in size depending on whether either relative, natural or reference point Cartesian coordinates are adopted. Second, once such a choice has been made, different solution strategies can be followed. It seems that formalisms based on redundant coordinates are often used in commercial software, whereas those based on a minimum number of coordinates are usually preferred in real‐time computations.In this paper, with reference to models with redundant absolute coordinates, the problem of coordinate reduction will be discussed and a group of 11 different methods will be compared on the basis of their computational efficiency. In particular, methods based on constraint orthogonalization and on the use of pseudoinverse matrices have been selected, together with other methods based on least‐squares block solution. The methods have been implemented on three different test cases. The main purpose is to provide hints and guidelines on the choice and availability of solution strategies during simulation of moderate size multibody systems. Copyright © 2011 John Wiley & Sons, Ltd.
H2 filter design for discrete‐time Markov jump linear systems with partly unknown transition probabilities
Authors: Shen Mouquan , Yang Guang‐Hong 
Published: March 2011

SUMMARYThe H2 filter design problem for discrete‐time Markov jump linear systems with partly unknown transition probabilities is addressed in this paper. The so‐called partly unknown transition probabilities cover two cases: one is that some unknown elements have known lower and upper bounds, the other is that some unknown elements have no information available. By employing Finsler's lemma and linear matrix inequality (LMI) technique, sufficient conditions are developed in the LMI setting to design an H2 filter such that the filtering error system is mean‐square stable and at the same time satisfies a prescribed H2 performance index. Numerical examples are presented to illustrate the effectiveness of the developed theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of mesoporous silica and its modification of bismaleimide/cyanate ester resin with improved thermal and dielectric properties
Authors: Hu Jiang‐tao , Gu Aijuan , Liang Guozheng , Zhuo Dongxian , Yuan Li 
Published: March 2011

AbstractA novel method is proposed to synthesize new mesoporous silica containing amine groups (MPSA), and it was further employed to modify bismaleimide‐dialllyl bisphenol (BD)/cyanate ester (CE) resin to form novel MPSA/BD/CE hybrids; in addition, the typical properties of MPSA/BD/CE were systematically investigated. Results show that these hybrids have very low dielectric constant and loss as well as good thermal properties. Compared with BD/CE resin, all hybrids have not only decreased dielectric constant and loss but also similar dependence of dielectric properties on frequency over the whole frequency from 10 to 106 Hz. Specifically, with the addition of MPSA to BD/CE resin, the dielectric constant reduces from 3.5 to 3.0, and the dielectric loss is only 85% of that of BD/CE resin. Note that all hybrids show better thermal resistance (reflected by higher glass transition temperature, decreased maximum degradation rate, and higher char yield at 800°C) than BD/CE resin. All these differences in macro‐properties are attributed to the different structure between MPSA/BD/CE hybrids and BD/CE resin. Copyright © 2011 John Wiley & Sons, Ltd.