bluuebunny/crossref_metadata_2025_split huggingface dataset:
Male reproductive strategies in black and gold howler monkeys (Alouatta caraya)
Authors: Oklander Luciana I. , Kowalewski Martin , Corach Daniel 
Published: September 2013

AbstractBehavioral and demographic factors such as group size, social structure, dispersal patterns, and mating systems affect male reproductive success. In the present study, we analyze the relationship between social structure, genetic relatedness of adult males and offspring paternity in one population ofAlouatta carayainhabiting a continuous forest in Northern Argentina. After 14 months of behavioral studies and genotyping 11 microsatellites, we found that dominant or central males achieved greater mating success and fathered all the offspring conceived during our study in two multimale–multifemale groups (both including three adult males). Although skewed toward the dominant males, females copulated with almost all resident males and with extra group males. We found significantly fewer agonistic interactions between adult males in the group with fewer females and where males were more genetically related to each other (average relatednessr = 0.237; 0.015 int/ind/hr vs.r = 0.02; 0.029 int/ind/hr). Paternity was also analyzed in two other neighboring groups which also showed strong skew to one male over a 2‐year period. These results reveal that even though female black and gold howlers mate with many males, infants are typically fathered by one dominant male. Am. J. Primatol. 76:43–55, 2014. © 2013 The Authors.American Journal of PrimatologyPublished by Wiley Periodicals, Inc.
Process safety in using NH3 as refrigerant in Indian ice making plants: case studies followed by policy recommendations
Authors: Mandal Prasun Kumar , Bandyopadhyay Amitava 
Published: September 2013

ABSTRACTAmmonia is used as refrigerant in microscale ice making plants in rural areas of India. Many of these are operated unmanned sometimes and thus NH3 leakage is a very common environmental hazard. Studies do not seem to have been reported on the safety management of this sector yet. In this light, the present article attempts to investigate into the safety management practices to such plants. In the first part, an assessment is made on the basis of various process‐related data provided by the owners. For instance, the raw material consumptions are verified through subjective and objective judgments with scientific insights. In the second part, the differences existing in the safety management practices between the microscale and the small/medium‐scale units during NH3 leakage are elucidated through case studies. Finally, few recommendations are put forward for strengthening the Indian safety management policies for ice making plants in rural India. Copyright © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.
Functionalization of polyvinyl alcohol hydrogels with graphene oxide for potential dye removal
Authors: Li Chengpeng , She Mary , She Xiaodong , Dai Jane , Kong Lingxue 
Published: September 2013

ABSTRACTBecause of highly frozen macromolecule chains, polyvinyl alcohol (PVA) hydrogels have never been used for dye removal. This work focuses on improving the adsorption capacity of the PVA hydrogel by using amphiphilic graphene oxide to improve its macromolecular chain mobility in crystal domain and introduce new functional groups. To evaluate its effectiveness, crystal structure, swelling kinetics, and model dye methylene blue (MB) adsorption of the as‐prepared PVA hybrid hydrogels were systematically investigated. The results indicate that the hybrid PVA hydrogels have lower crystallinity and less crystal stability, demonstrating the improved macromolecular chain mobility. Moreover, improved swelling ratios of PVA/GO hydrogels also illustrate the enhanced macromolecular chain mobility. MB adsorption experiment indicates that GO introduced can result in great improvement in MB adsorption. And the adsorption process follows the second‐order kinetic model and Morris–Weber model, which is determined by the intraparticle diffusion. Furthermore, MB adsorption isotherm follows Freundlich model and the adsorption is heterogeneous. Desorption studies indicate that the interaction between PVA hydrogels and MB consists of both physisorption and chemisorption. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39872.
Robust Control System Design for an Uncertain Nonlinear System Using Minimax LQG Design Method
Authors: Ur Rehman Obaid , Fidan Bariş , Petersen Ian R. 
Published: September 2013

ABSTRACTA systematic approach to design a nonlinear controller using minimax linear quadratic Gaussian regulator (LQG) control is proposed for a class of multi‐input multi‐output nonlinear uncertain systems. In this approach, a robust feedback linearization method and a notion of uncertain diffeomorphism are used to obtain an uncertain linearized model for the corresponding uncertain nonlinear system. A robust minimax LQG controller is then proposed for reference command tracking and stabilization of the nonlinear system in the presence of uncertain parameters. The uncertainties are assumed to satisfy a certain integral quadratic constraint condition. In this method, conventional feedback linearization is used to cancel nominal nonlinear terms and the uncertain nonlinear terms are linearized in a robust way. To demonstrate the effectiveness of the proposed approach, a minimax LQG‐based robust controller is designed for a nonlinear uncertain model of an air‐breathing hypersonic flight vehicle (AHFV) with flexibility and input coupling. Here, the problem of constructing a guaranteed cost controller which minimizes a guaranteed cost bound has been considered and the tracking of velocity and altitude is achieved under inertial and aerodynamic uncertainties.
Polymer‐based alternative method to extract bromelain from pineapple peel waste
Authors: de Lencastre Novaes Letícia Celia , de Carvalho Santos Ebinuma Valéria , Mazzola Priscila Gava , Júnior Adalberto Pessoa 
Published: September 2013

AbstractBromelain is a mixture of proteolytic enzymes present in all tissues of the pineapple (Ananas comosus Merr.), and it is known for its clinical therapeutic applications, food processing, and as a dietary supplement. The use of pineapple waste for bromelain extraction is interesting from both an environmental and a commercial point of view, because the protease has relevant clinical potential. We aimed to study the optimization of bromelain extraction from pineapple waste, using the aqueous two‐phase system formed by polyethylene glycol (PEG) and poly(acrylic acid). In this work, bromelain partitioned preferentially to the top/PEG‐rich phase and, in the best condition, achieved a yield of 335.27% with a purification factor of 25.78. The statistical analysis showed that all variables analyzed were significant to the process.
Plac1 (placenta‐specific 1) is widely expressed during fetal development and is associated with a lethal form of hydrocephalus
Authors: Kong Xiaoyuan , Jackman Suzanne M. , Fant Michael E. 
Published: September 2013

BACKGROUNDPlac1 is an X‐linked gene essential for normal placental development. Plac1 ablation is associated with placentomegaly and intrauterine growth retardation. Additionally, Plac1‐null mice exhibit reduced postnatal viability. This study was conducted as part of our ongoing examination of the postnatal phenotype associated with Plac1 ablation.METHODSPlac1 was deleted in murine embryonic stem cells and bred against a C57BL/6 background. Mutant mice were genotyped using a polymerase chain reaction–based strategy. Embryonic Plac1 expression was assessed by quantitative real‐time polymerase chain reaction, in situ hybridization, and β‐galactosidase expression.RESULTSA total of 20% of the surviving Xm‐Y (knockout) males as well as 10–15% of the Xm‐X females (mutant maternal allele) developed lethal hydrocephalus at 4–8 weeks. By contrast, XXp‐ hets (paternal null allele) did not. Plac1 mRNA expression was detected in the fetal brain that markedly decreased after birth. Plac1 mRNA expression localized to the hindbrain and lateral ventricles of wild‐type embryos. Additionally, Plac1 expression was observed throughout the fetus including the fetal lungs, kidney, intestine, liver, and heart. Embryonic Plac1 expression was paternally imprinted with partial escape of the paternal allele from complete inactivation. The Plac1 protein localized to the apical surface of the epithelial cells lining the developing airways of the lung and proximal renal tubules, consistent with its localization in the differentiated syncytiotrophoblast.CONCLUSIONPlac1 is expressed in the brain in a developmentally regulated manner and its absence is linked to increased risk for hydrocephalus. It is also widely expressed in fetal tissues expanding the existing paradigm to include direct tissue‐specific roles during development. Birth Defects Research (Part A) 97:571–577, 2013. © 2013 Wiley Periodicals, Inc.
LRP5 knockdown: effect on prostate cancer invasion growth and skeletal metastasis in vitro and in vivo
Authors: Rabbani Shafaat A. , Arakelian Ani , Farookhi Riaz 
Published: September 2013

AbstractProstate cancer (PCa) is a common hormone‐dependent malignancy associated with the development of skeletal metastases. This is due to the increased expression of a number of growth factors, cytokines, and proteases which collectively drive the metastatic cascade in general and increased propensity to develop skeletal metastasis in particular. While a number of signaling pathways have been implicated in PCa progression, the highly complex wnt/β‐catenin pathway is unique due to its ability to regulate gene expression, cell invasion, migration, survival, proliferation, and differentiation to contribute in the initiation and progression of PCa. Members of the wnt family bind to the Frizzle proteins or lipoprotein‐related receptor proteins 5, 6 (LRP5, ‐6) to activate this key pathway. In the current study, we have investigated the role of wnt/β‐catenin pathway in PCa progression, skeletal metastasis, and gene expression using the dominant negative plasmid of LRP5 (DN‐LRP5) and human PCa cells PC‐3. Inactivation of LRP5 resulted in mesenchymal to epithelial shift, lack of translocation of β‐catenin to cell surface, increased tumor cell proliferation, decreased colony formation, migration and invasion in vitro. These effects were attributed to decreased expression of pro‐invasive and pro‐metastatic genes. In in vivo studies, PC‐3‐DN‐LRP5 cells developed significantly smaller tumors and a marked decrease in skeletal lesion area and number as determined by X‐ray, micro (μ) CT and histological analysis. Collectively results from these studies demonstrate the dominant role of this key pathway in PCa growth and skeletal metastasis and its potential as a viable therapeutic target.
Copper(II)‐bis‐Histidine Coordination Structure in a Fibrillar Amyloid β‐Peptide Fragment and Model Complexes Revealed by Electron Spin Echo Envelope Modulation Spectroscopy
Authors: Hernández‐Guzmán Jessica , Sun Li , Mehta Anil K. , Dong Jijun , Lynn David G. , Warncke Kurt 
Published: September 2013

AbstractTruncated and mutated amyloid‐β (Aβ) peptides are models for systematic study—in homogeneous preparations—of the molecular origins of metal ion effects on Aβ aggregation rates, types of aggregate structures formed, and cytotoxicity. The 3D geometry of bis‐histidine imidazole coordination of CuIIin fibrils of the nonapetide acetyl‐Aβ(13–21)H14A has been determined by powder14N electron spin echo envelope modulation (ESEEM) spectroscopy. The method of simulation of the anisotropic combination modulation is described and benchmarked for a CuII‐bis‐cis‐imidazole complex of known structure. The revealed bis‐ciscoordination mode, and the mutual orientation of the imidazole rings, for CuIIin Ac‐Aβ(13–21)H14A fibrils are consistent with the proposed β‐sheet structural model and pairwise peptide interaction with CuII, with an alternating [‐metal‐vacancy‐]npattern, along the N‐terminal edge. Metal coordination does not significantly distort the intra‐β‐strand peptide interactions, which provides a possible explanation for the acceleration of Ac‐Aβ(13–21)H14A fibrillization by CuII, through stabilization of the associated state and low‐reorganization integration of β‐strand peptide pair precursors.
The Multivalent Effect in Glycosidase Inhibition: Probing the Influence of Valency, Peripheral Ligand Structure, and Topology with Cyclodextrin‐Based Iminosugar Click Clusters
Authors: Decroocq Camille , Joosten Antoine , Sergent Raphaël , Mena Barragán Teresa , Ortiz Mellet Carmen , Compain Philippe 
Published: September 2013

AbstractIn view of recent reports of a strong multivalent effect in glycosidase inhibition, a library of β‐CD‐based multivalent iminosugars has been efficiently synthesized by way of CuI‐catalyzed azide–alkyne cycloaddition (CuAAC). In combination with the first application of isothermal titration calorimetry (ITC) experiments to the study of multivalent iminosugar–enzyme interactions, the inhibition properties of these click clusters were evaluated on a panel of glycosidases. The structural parameters that were varied include valency, peripheral ligand structure, and topology. The inhibition results obtained with the iminosugar clusters further highlight the importance of multivalency in the inhibition of α‐mannosidase. Generally, the evaluated multivalent iminosugars displayed comparable thermodynamic signatures of binding towards α‐mannosidase (Jack bean): that is, large negative enthalpies of complexation coupled with small entropies of either sign. In addition, the enthalpy–entropy compensation observed in all tested cases may be attributed to a common mechanism of dissociation for the enzyme–multivalent iminosugar interactions. The measured binding stoichiometries indicated that each iminosugar cluster interacts with no more than one protein molecule.
Fischer–Tropsch Synthesis Over Skeletal FeCe Catalysts Leached from Rapidly Quenched Ternary FeCeAl Alloys
Authors: Sun Bo , Lin Jun , Xu Ke , Pei Yan , Yan Shirun , Qiao Minghua , Zhang Xiaoxin , Zong Baoning 
Published: September 2013

AbstractThe new Ce‐promoted skeletal Fe catalysts with different Ce contents were prepared through alkali leaching of rapidly quenched ternary FeCeAl alloys and evaluated in the gas‐phase Fischer–Tropsch synthesis reaction. N2 physisorption and XRD analysis confirmed the function of Ce as a structural promoter. In the Fischer–Tropsch synthesis reaction, the incorporation of Ce markedly improved the activity and selectivity to C5+ hydrocarbons. Characterizations of the catalysts after Fischer–Tropsch synthesis confirmed the function of Ce as a chemical promoter. We also confirmed that the catalytic activity is associated with the concentrations of the surface polymeric and, to a lesser extent, atomic carbonaceous species and the C5+ selectivity correlated well with the surface concentration of Hägg carbide. We identified a linear relationship between the concentrations of the CeIII cations and Hägg carbide, which clearly substantiated the hypothesis that the chemical effect of Ce is mediated by the Fe0CeIII ensembles facilitating the formation of Hägg carbide.
Nucleation Kinetics and Growth Model of Penicillin Sulfoxide in Butyl Acetate
Authors: Jing D. , Wang J. , Zhang M. , Wang Y. , Xie C. 
Published: September 2013

AbstractNucleation kinetics and a growth model of penicillin sulfoxide in butyl acetate were studied. Nucleation parameters such as energy per unit volume, radius of critical nucleus, critical free energy barrier, and nucleation rate were evaluated. A laser method was selected to detect the first crystal in induction period studies. By means of scanning electron microscopy and surface entropy factor, the growth model of penicillin sulfoxide developed from butyl acetate could be determined.
Structure and Catalytic Performance of Mg‐SBA‐15‐Supported Nickel Catalysts for CO2 Reforming of Methane to Syngas
Authors: Zhang H. , Li M. , Xiao P. , Liu D. , Zou C. J. 
Published: September 2013

AbstractA series of Mg‐modified SBA‐15 mesoporous silicas with different MgO contents were successfully synthesized by a simple one‐pot synthesis method and further impregnated with Ni. The Mg‐modified SBA‐15 materials and supported Ni catalysts were characterized by N2 physisorption (BET), X‐ray diffraction (XRD), temperature‐programmed desorption of CO2 (CO2‐TPD), temperature‐programmed H2 reduction (H2‐TPR), and temperature‐programmed hydrogenation (TPH) techniques and used for methane dry reforming with CO2. CO2‐TPD results proved that the addition of Mg increased the total amount of basic sites which was responsible for the enhanced catalytic activity over the Mg‐modified Ni catalyst. The excellent catalytic stability of Ni/8Mg‐SBA‐15 was ascribed to less coking and higher stability of the Ni particle size due to the introduction of Mg.
Oxygen Mass Transfer Rate in a Pressurized Lab‐Scale Stirred Bioreactor
Authors: Lopes M. , Mota M. , Belo I. 
Published: September 2013

AbstractOxygen mass transfer from air to the liquid phase in bioreactors with aerobic cultures has long been a serious impairment to the productivity of various bioprocesses. An increase of the oxygen mass transfer rate (OTR) can be the key to overcome oxygen limitation. The influence of higher air pressure on OTR was measured and a significantly enhanced OTR could be obtained. The oxygen volumetric mass transfer coefficient (kLa) was described by a function of the air pressure in a stirred lab‐scale pressurized bioreactor. The correlation obtained proved that kLa slightly decreased with higher air pressure, following a power function.
Synthesis and Characterization of Amorphous Nano‐Alumina Powders with High Surface Area for Biodiesel Production
Authors: Amini G. , Najafpour G. D. , Rabiee S. M. , Ghoreyshi A. A. 
Published: September 2013

AbstractNano‐alumina powders containing yttrium oxide were synthesized via the sol‐gel method using aluminum chloride hexahydrate as catalyst precursor. Fourier transform infrared analysis showed the presence of Al‐O and Al‐O‐Al bands in the powder structure and X‐ray diffraction spectra proved that the alumina was in the amorphous phase. The amorphous nano‐alumina powders were shown to be mesoporous with a high surface area, and both spherical and slit‐shaped particles were found in the calcined powder. A high percentage of conversion of oil to biodiesel was obtained in the transesterification reaction and the synthesized nano‐alumina powders could be easily regenerated for further use. The amorphous nano‐alumina powder can thus be recommended for use as active catalyst in the transesterification reaction for biodiesel production on the industrial scale.
High‐Pressure Generator of Singlet Oxygen
Authors: Jirásek V. , Čenský M. , Špalek O. , Kodymová J. 
Published: September 2013

AbstractThe generation of gaseous singlet oxygen by gas‐liquid reaction of chlorine with alkaline solution of hydrogen peroxide in spray form was studied experimentally on the originally designed device with a fast separation of reacted liquid from gas. The singlet oxygen yield, residual chlorine, and water vapor content in gas were measured under different experimental conditions of the centrifugal spray singlet oxygen generator (CSSOG) using nitrogen as a dilution gas. A characteristic feature of the CSSOG is a high utilization of the chemicals and production of singlet oxygen at a very high total pressure even near the atmospheric pressure. This generator developed originally for driving a chemical oxygen‐iodine laser (COIL) could be employed also as an efficient singlet oxygen source in material science, chemical synthesis, and others.
Drop Detachment from a Micro‐Engineered Membrane Surface in a Dynamic Membrane Emulsification Process
Authors: Holzapfel S. , Rondeau E. , Mühlich P. , Windhab E. J. 
Published: September 2013

AbstractDrop size distribution is an important characteristic of emulsions, probably the most crucial one for their use in various applications. Here, a pilot‐scale apparatus with a cone‐shaped flow geometry is introduced. The plate contains a micro‐engineered membrane manufactured from silicon allowing for the production of emulsions with narrow drop size distributions. The process is characterized by producing model emulsions of the oil‐in‐water type under laminar rheometric flow conditions and by accessing the regime of drop detachment as a function of the wall shear stress applied, by means of high‐speed imaging in a separate flow cell. Furthermore, clear evidence is given of the crucial influence of the membrane wetting properties on the emulsification results, by comparing the performance of micro‐engineered membranes composed either of silicon, silicon nitride, or nickel, for pore diameters from 1 to 12 μm, in the flow cell.
A Standard Procedure for the Selection of Solvents for Natural Plant Extraction in the Early Stages of Process Development
Authors: Bergs D. , Merz J. , Delp A. , Joehnck M. , Martin G. , Schembecker G. 
Published: September 2013

AbstractThe standard procedure for the selection of solvents for natural plant extraction is a hybrid approach of solubility estimation and experimental investigations to reduce the time of solvent screening to a minimum. The focus is on the selection of a suitable solvent for natural product extraction in the early stages of process development when thermodynamic data are not yet available and solid‐liquid extraction is still an alternative to other techniques. The standard procedure is implemented in Microsoft® Excel™, provides the necessary information, creates experimental test plans, performs calculations and supports the user by structured descriptions to select the most desirable solvent for extraction. In this study, its application to the natural products rebaudioside A from Stevia rebaudiana Bertoni leaves, caffeine from guaraná seeds, and artemisinin from Artemisia annua leaves is demonstrated. The standard procedure predicted solvents that were found in the literature, plus solvents with even better extraction performance than the ones described in the literature.
The Catalytic Mechanism of Protein Phosphatase 5 Established by DFT Calculations
Authors: Ribeiro António J. M. , Alberto Marta E. , Ramos Maria J. , Fernandes Pedro A. , Russo Nino 
Published: September 2013

AbstractIn order to elucidate the catalytic mechanism of the Mn–Mn containing serine/threonine protein phosphatase 5 (PP5), we present a density functional theory study with a cluster model approach. According to our results, the reaction occurs through an in‐line concerted transition state with an energy of 15.8 kcal mol−1, and no intermediates are formed. The important role played by His304 and Asp274 as stabilizers of the leaving group has been shown, whereas the role played by the metal ions seems to be mostly electrostatic. The indispensable requirement of having a neutral active center has been demonstrated by testing different protonation states of the cluster model. We have shown also the importance of describing properly the electronic configuration of the Mn–Mn binuclear centers.