bluuebunny/crossref_metadata_2025_split huggingface dataset:
Greater Growth of Proximal Metatarsals in Bird Embryos and the Evolution of Hallux Position in the Grasping Foot
Authors: Botelho João Francisco , Smith‐Paredes Daniel , Soto‐Acuña Sergio , Núñez‐León Daniel , Palma Verónica , Vargas Alexander O. 
Published: September 2016

ABSTRACTIn early theropod dinosaurs—the ancestors of birds—the hallux (digit 1) had an elevated position within the foot and had lost the proximal portion of its metatarsal. It no longer articulated with the ankle, but was attached at about mid‐length of metatarsal 2 (mt2). In adult birds, the hallux is articulated closer to the distal end of mt2 at ground level with the other digits. However, on chick embryonic day 7, its position is as in early theropods at half‐length of mt2. The adult distal location is acquired during embryonic days 8–10. To assess how the adult phenotype is acquired, we produced fate maps of the metatarsals of day 6 chicken embryos injecting the lipophilic tracer DiI. The fates of these marks indicate a larger expansion of the metatarsals at their proximal end, which creates the illusory effect that d1 moves distally. This larger proximal expansion occurs concomitantly with growth and early differentiation of cartilage. Histological analysis of metatarsals shows that the domains of flattened and prehypertrophic chondrocytes are larger toward the proximal end. The results suggest that the distal position of the hallux in the avian foot evolved as a consequence of an embryological period of expansion of the metatarsus toward the proximal end. It also brings attention to the developmental mechanisms leading to differential growth between epiphyses and their evolutionary consequences.
Mathematics as a conduit for translational research in post‐traumatic osteoarthritis
Authors: Ayati Bruce P. , Kapitanov Georgi I. , Coleman Mitchell C. , Anderson Donald D. , Martin James A. 
Published: September 2016

ABSTRACTBiomathematical models offer a powerful method of clarifying complex temporal interactions and the relationships among multiple variables in a system. We present a coupled in silico biomathematical model of articular cartilage degeneration in response to impact and/or aberrant loading such as would be associated with injury to an articular joint. The model incorporates fundamental biological and mechanical information obtained from explant and small animal studies to predict post‐traumatic osteoarthritis (PTOA) progression, with an eye toward eventual application in human patients. In this sense, we refer to the mathematics as a “conduit of translation.” The new in silico framework presented in this paper involves a biomathematical model for the cellular and biochemical response to strains computed using finite element analysis. The model predicts qualitative responses presently, utilizing system parameter values largely taken from the literature. To contribute to accurate predictions, models need to be accurately parameterized with values that are based on solid science. We discuss a parameter identification protocol that will enable us to make increasingly accurate predictions of PTOA progression using additional data from smaller scale explant and small animal assays as they become available. By distilling the data from the explant and animal assays into parameters for biomathematical models, mathematics can translate experimental data to clinically relevant knowledge. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:566–572, 2017.
Behavioral development and habitat structure affect postfledging movements of songbirds
Authors: Jenkins Julianna M. A. , Thompson Frank R. , Faaborg John 
Published: September 2016

ABSTRACTPostfledging survival of neotropical migrant songbirds has been linked to seasonal and annual changes in the environment and to individual condition. Understanding what influences variation in postfledging movements may provide insight into the differential value of habitat across life‐history stages. We conducted a radio‐telemetry study of postfledging ovenbirds (Seiurus aurocapilla; n = 45) and Acadian flycatchers (Empidonax virescens; n = 62) in mature‐forest fragments from 2012 to 2015 in Missouri, USA. We documented variability in behavior and space use and used generalized linear mixed models to evaluate the relationship of postfledging movement rates to individuals’ condition, temporal variables, and local habitat variables. We found effects of age and season on movement distances for both study species. Additionally, daily movements of fledgling ovenbirds were negatively related to understory foliage density, a characteristic previously linked to increased survival. Habitat features are useful in predicting the postfledging movements of ovenbirds. By including behavioral development (age) and season in movement models, we were able to isolate and detect habitat effects on movement of ovenbirds and Acadian flycatchers. We suggest researchers use models of daily movement to further strengthen resource quality hypotheses generated by habitat selection and survival studies. © 2016 The Wildlife Society.
Habitat modification as a means of restoring crested auklet colonies
Authors: Major Heather L. , Buxton Rachel T. , Schacter Carley R. , Conners Melinda G. , Jones Ian L. 
Published: September 2016

ABSTRACTSeabirds that forage in dense groups can be especially vulnerable to anthropogenic threats at sea. To mitigate these threats to populations, nesting habitat restoration may be a viable option by reducing negative density dependence. Accordingly, we undertook a before‐after control‐impact (BACI) experiment to test whether habitat modification could be an effective means of restoring nesting habitat of crested auklets (Aethia cristatella) breeding on Gareloi Island, Alaska, USA. Despite supporting large numbers of crevice‐nesting auklets, many lava flows at Gareloi Island are in a stage of late vegetative succession that may prevent birds from accessing subterranean nesting habitat. We hypothesized that crested auklet density is highest in unvegetated blocky and porous lava, and predicted that removing vegetation from the surface would allow new recruits to secure previously unavailable nesting sites. In 2009 and 2010, we delineated 34 200‐m2 plots throughout the southeast colony at Gareloi, and color marked a subset of crested auklets landing in each plot to measure movement and abundance. We removed vegetative overgrowth and peat from half of each plot at the end of the 2009 (4 plots) and 2010 (30 plots) breeding seasons. Before and after vegetation removal, we counted the number of active nesting sites and calculated the ratio of banded to un‐banded breeders on the surface of each plot half. Overall, active nesting sites, number of individuals on the surface, and number of breeders landing did not increase after vegetation removal. However, among banded individuals that moved among plot halves, birds were 1.7 times more likely to move to a de‐vegetated plot half. Based on our experimental results, we found no evidence that vegetation removal increased crested auklet numbers at Gareloi Island, and thus in the short term this may not be a viable option for increasing crested auklet abundance. © 2016 The Wildlife Society.
Processing and Characterization of Composites Curing by Microwave Irradiation
Authors: Kersting Daniel F. , Wiebeck Helio , Esper Fábio J. 
Published: September 2016

SummaryThe present study aimed to assess the curing of composites based on fiberglass and epoxy resin subjected to various microwave irradiation power level and time. The conditions studied were monitored in order to provide thermal images of different times during the irradiation, allowing the visualization of the temperature distribution over time on the test specimens . The heating profile tests resulted in samples that were later analyzed. Pores and voids content, density and thickness were also evaluated according to ASTM. The existing composite were then analyzed via optical microscopy.The samples obtained by thermal curing are less than the amount of pores and voids. Moreover, the cure via microwave required only twenty minutes to accomplish what has been produced in more than thirty hours of thermal curing.
Influence of Binary Curing System on the Nitrile Rubber Mechanical Properties
Authors: Linhares Felipe N. , Kersch Michaela , Sousa Ana Maria F. , Leite Marcia Christina A.M. , Altstädt Volker , Furtado Cristina R.G. 
Published: September 2016

SummaryThe effect of different sulphur‐based curing systems on the nitrile rubber mechanical properties was assessed. High acrylonitrile content nitrile rubber compositions were prepared with different amounts of N‐cyclohexyl‐2‐benzothiazole‐sulfenamide (CBS), tetramethylthiuram disulfide (TMTD) and sulphur. The following tests were conducted: crosslink density, hardness, and stress‐strain tests. Scanning electron microscopy, infrared and NMR spectroscopies, and statistical analyses were carried out to bring new interesting aspects to this topic. Crosslink density was statistically influenced by the amount of TMTD and sulphur, whereas no significance was observed for CBS content. Tensile strength was above the optimum point regarding the crosslink density. Time‐dependent exudation of TMTD was observed when added in higher concentration.
Mechanical and Thermal Behavior of PLA/PEgAA Blends
Authors: de Araújo Jeane P. , Silva Reinaldo C. , Lima Jéssica C. C. , Agrawal Pankaj , de Mélo Tomás J. A. 
Published: September 2016

SummaryThe aim of this work was to evaluate the effect different polyethylene grafted with acrylic acid (PEgAA) copolymer content on the mechanical and thermal properties and morphology of poly(lactic acid) (PLA) biopolymer. The PLA/PEgAA blends containing 5, 10, 15 and 20% (wt) of PEgAA copolymer were prepared by extrusion followed by injection molding and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA), mechanical properties and Scanning Electron Microscopy (SEM). FTIR analysis indicated that a polyesterification reaction between the hydroxyl groups of PLA and the carboxyl groups of PEgAA may have occurred. DSC and DMTA analyzes indicated that the addition of PEgAA to PLA lead to the decrease in cold crystallization (Tcc) temperature of PLA. The impact strength of PLA was increased with the increase in the PEgAA content up to 15%. The PEgAA domains size increased with the increase in the PEgAA content, indicating a weak interaction between the PLA and PEgAA phases.
Nanocomposites of Polyethylene Blends Using Organomica
Authors: Oliveira Patrícia L. , Araújo Rafael S. , Oliveira Vital R. , Morais Jacson S. , de Fátima V. Marques Maria 
Published: September 2016

SummaryThis study aims to incorporate LLDPE into HDPE in order to improve its processability, as well as to employ a nanoclay for maintaining the HDPE stiffness. Thermal, dynamic‐mechanical and rheological properties of polyethylene composites were investigated. Muscovite mica was treated with lithium nitrate for seven cycles, followed by exchange with quaternary ammonium salt to produce organomica. Initially, organomica was added to HDPE at 2% wt. using a tween‐screw mini‐extruder. The blend HDPE/LLDPE (1:1 by weight) was also evaluated at the same mica content, with and without the introduction of maleated polyethylene (PEMA) as compatibilizer in order to increase adhesion of polymers with the mineral clay. The samples were evaluated by thermogravimetry (TGA), while melting and crystallization temperatures, and the degree of crystallinity were measured by differential scanning calorimetry (DSC). Rheological properties were evaluated during blending using viscosity and torque curves as a function of processing time. The results showed that stability to thermal degradation of the polyethylene blend with mica increased with the addition of 2% wt. PEMA, where the temperature of maximum degradation rate overcame that of HDPE. The melting endotherm remained narrow in the mixture HDPE/LLDPE/mica, showing good miscibility of the polymer blend; and there was a slight decrease in the melting temperature. The reduction in viscosity during blending revealed improved processing conditions.
Mechanical and Morphological Properties of PLA/BioPE Blend Compatibilized with E‐GMA and EMA‐GMA Copolymers
Authors: Brito Gustavo F. , Agrawal Pankaj , Mélo Tomás J. A. 
Published: September 2016

SummaryIn this work, the effect of Ethylene‐Glycidyl Methacrylate (E‐GMA) and Ethylene‐Methyl Acrylate‐Glycidyl Methacrylate (EMA‐GMA) copolymers on the mechanical and morphological properties on the blends of poly (lactic acid) (PLA) with biopolyethylene (BioPE) was evaluated. Uncompatibilized and compatibilized blends were prepared by extrusion followed by injection molding and characterized by Melt Flow Index (MFI), Fourier Transform Infrared Spectroscopy (FTIR), mechanical properties, Scanning (SEM) and Transmission electron microscopy (TEM). The results of mechanical tests showed that E‐GMA and EMA‐GMA copolymers acted promoting the compatibilization of the PLA/BioPE blend. MFI measurements along with FTIR and morphology analysis by SEM indicated the formation of in‐situ copolymers due to reactions between hydroxyl and carboxyl functional groups of PLA and the epoxy groups of E‐GMA and EMA‐GMA copolymers.
Preparation of Polyurethane Foams Based on Maltodextrin and Their Potential Use in Methyl Ester (Biodiesel) Purification
Authors: Kubota Tatiana , de Araújo Márcia Valéria Gaspar , de Sá Daniel Jorge Cardoso , Luneli Carlos Eduardo , Barbosa Ronilson Vasconcelos , Ramos Luiz Pereira , Zawadzki Sônia Faria 
Published: September 2016

SummaryBiodiesel can be obtained by transesterification of the triglycerides present in the vegetable oil and animal fat. After the reaction it is necessary to purify the alkyl esters. One way to obtain this is making the dry wash. Thus, this study proposes the preparation of polyurethane foams with maltodextrin as sorbents for use in the biodiesel purification. The foams were prepared and characterized by ATR‐FTIR, TGA, DSC and water absorption test (ASTM D570). The FTIR spectra showed typical bands of polyurethane, TGA curves showed weight loss in two stages, the DSC analysis of the foams based on maltodextrin revealed a Tg value higher than that observed for the control foam, moreover, the absorption test in water showed that the foams based on maltodextrin showed a more hydrophilic character. The efficiency of the foams as possible sorbents for biodiesel purification was monitored by two indicators: soap concentration (AOCS Cc 17‐19) and acidity index (AOCS Ca 5a‐40). The results indicated that the foams were promising candidates in the removal of contaminants.
Evaluation of Thermal Properties of Nanocomposites Based on Ecobras Matrix and Vermiculite Modified with Alkylphosphonium Salt
Authors: Oliveira Marcelo F. L. , Braga Fernanda C. F. , Leite Márcia C. A. M. , Oliveira Marcia G. 
Published: September 2016

SummaryThe use of biodegradable polymers to produce nanocomposites with mineral fillers leads to the production of new materials with low cost and reduced environmental impact, combined with improvements in mechanical and thermal properties. Nanocomposites based on poly(butylene adipate‐co‐terephthalate) and starch blend (Ecobras) and vermiculite (VMT) modified with hexadecyltributylphosphonium bromide (P‐VMT) were prepared by melt intercalation in a mixing chamber at 140 °C, keeping the amount of clay at 4%wt. The intercalation of P‐VMT in Ecobras was characterized by X‐ray diffraction (XRD) and infrared spectroscopy (FTIR). VMT organophilization was confirmed by the appearance of FTIR bands characteristic of the long alkyl chain of the phosphonium salt used and also by displacement of the basal peak towards lower 2θ values in the diffractogram compared to pure vermiculite. The thermal properties of Ecobras and its compositions were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The addition of VMT and P‐VMT in Ecobras increased the crystallization temperature (Tc) and crystalline melting temperature (Tm), as observed by DSC analysis. The result of the thermogravimetric analysis showed that the addition of P‐VMT in Ecobras improved thermal stability of the nanocomposite. The Young's modulus of the composite with 4 wt% of P‐VMT indicated an increase in stiffness compared to the pure matrix.
Preparation and Characterization of Okra Mucilage (Abelmoschus esculentus) Edible Films
Authors: de Alvarenga Pinto Cotrim Monique , Mottin Artur Caron , Ayres Eliane 
Published: September 2016

SummaryOkra (Abelmoschus esculentus) is a perishable fruit with an extremely short post‐harvesting period. In the present study we have investigated the development of edible films obtained from mucilage of rejected okra fruits. The obtained okra mucilage was characterized by FTIR, percentage yield, swelling index in water, percentage solubility in water, XRD, TGA and DSC. The TGA curve has showed that okra mucilage has good thermal stability and low moisture content, which was demonstrated by the low initial mass loss. Edible films were prepared with two mucilage concentrations (1% and 1.5% w/v) combined with three plasticizer contents (PEG‐200), 0.25%, 0.50% and 0.75% v/v. The produced films were evaluated for their wettability, folding endurance, water solubility and color analysis of L*a*b color parameters. All analyses have demonstrated that plasticizer plays a key role in the system. The results obtained indicated that okra mucilage has potential to be used as edible film.
PAVM: a framework for policy‐aware virtual machine management
Authors: Durrani Muhammad Nouman , Zahid Feroz , Shamsi Jawwad A. 
Published: September 2016

SummaryThe problem of efficient placement of virtual machines (VMs) in cloud computing infrastructure is well studied in the literature. VM placement decision involves selecting a physical machine in the data center to host a specific VM. This decision could play a pivotal role in yielding high efficiency for both the cloud and its users. Also, reallocation of VMs could be performed through migrations to achieve goals like higher server consolidation or power saving. VM placement and reallocation decisions may consider affinities such as memory sharing, CPU processing, disk sharing, and network bandwidth requirements between VMs defined in multiple dimensions. Considering the NP‐hard complexity associated with computing an optimal solution for this VM placement decision problem, existing research employs heuristic‐based techniques to compute an efficient solution. However, most of these approaches are restricted to only a single attribute at a time. That is, a given technique of using heuristics to compute VM placement considers only a single attribute, while completely ignoring the impact of other dimensions of placing VMs. While this approach may improve the efficiency with respect to the affinity attribute in consideration, it may yield degraded performance with respect to other affinities. In addition, the criteria for determining VM‐placement efficiency may vary for different applications. Hence, the overall goal of achieving VM placement efficiency becomes difficult and challenging. We are motivated by this challenging problem of efficient VM placement and propose policy‐aware virtual machine management (PAVM), a generic framework that can be used for efficient VM management in a cloud computing platform based on the service provider‐defined policies to achieve the desired system‐wide goals. This involves efficient means to profile different VM affinities and to use profiled information effectively by intelligent and efficient VM migrations at run time considering multiple attributes at a time. By conducting extensive evaluation through simulation and real experiments that involve VM affinities on the basis of network and memory, we confirmed that the PAVM architecture is capable of improving the efficiency of a cloud system. We elaborate the architecture of a PAVM system, describe its implementation, and present details of our experiments. Copyright © 2016 John Wiley & Sons, Ltd.
Implicit dynamic analysis using an isogeometric Reissner–Mindlin shell formulation
Authors: Sobota P. M. , Dornisch W. , Müller R. , Klinkel S. 
Published: September 2016

SummaryIn isogeometric analysis, identical basis functions are used for geometrical representation and analysis. In this work, non‐uniform rational basis splines basis functions are applied in an isoparametric approach. An isogeometric Reissner–Mindlin shell formulation for implicit dynamic calculations using the Galerkin method is presented. A consistent as well as a lumped matrix formulation is implemented. The suitability of the developed shell formulation for natural frequency analysis is demonstrated by a numerical example. In a second set of examples, transient problems of plane and curved geometries undergoing large deformations in combination with nonlinear material behavior are investigated. Via a zero‐thickness stress algorithm for arbitrary material models, a J2‐plasticity constitutive law is implemented. In the numerical examples, the effectiveness, robustness, and superior accuracy of a continuous interpolation method of the shell director vector is compared with experimental results and alternative numerical approaches. Copyright © 2016 John Wiley & Sons, Ltd.
Novel deletion in 11p15.5 imprinting center region 1 in a patient with Beckwith–Wiedemann syndrome provides insight into distal enhancer regulation and tumorigenesis
Authors: Bachmann Nadine , Crazzolara Roman , Bohne Florian , Kotzot Dieter , Maurer Kathrin , Enklaar Thorsten , Prawitt Dirk , Bergmann Carsten 
Published: September 2016

AbstractBackgroundBeckwith–Wiedemann syndrome (BWS) is an early‐onset overgrowth disorder with a high risk for embryonal tumors. It is mainly caused by dysregulation of imprinted genes on chromosome 11p15.5; however, the driving forces in the development of tumors are not fully understood.ProcedureWe report on a female patient presenting with macrosomia, macroglossia, organomegaly and extensive bilateral nephroblastomatosis. Adjuvant chemotherapy was initiated; however, the patient developed hepatoblastoma and Wilms tumor at 5 and 12 months of age, respectively. Subsequent radiofrequency ablation of the liver tumor and partial nephrectomy followed by consolidation therapy achieved complete remission.ResultsMolecular genetic analysis revealed a maternally derived large deletion of the complete H19‐differentially methylated region (H19‐DMR; imprinting control region‐1 [ICR1]), the whole H19 gene itself as well as large parts of the distal enhancer region within the imprinting cluster‐1 (IC1). Extended analysis showed highly elevated insulin‐like growth factor 2 (IGF2) expression, possibly explaining at least in part the distinct BWS features and tumor manifestations.ConclusionsThis study of a large maternal deletion encompassing the H19 gene and complete ICR1 is the first to demonstrate transcriptional consequences on IGF2 in addition to methylation effects resulting in severe overgrowth and occurrence of multiple tumors in a BWS patient. Studying this deletion helps to clarify the complex molecular processes involved in BWS and provides further insight into tumorigenesis.