bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Clocks: Determining the Age of the Human–Chimpanzee Divergence
Authors: Jensen‐Seaman Michael I , Hooper‐Boyd Kathryn A 
Published: May 2013

Abstract

The approximate clocklike nature of the accumulation of nucleotide substitutions (the ‘molecular clock’) allows for the estimation of the time of divergence between modern species, dependent on calibrating the clock with known divergence dates from the fossil record. The use of fossils to calibrate divergence dates must be done thoughtfully, with an understanding that in most cases fossils provide a constraint on the minimal age of, rather than a true estimate of, the species divergence. Although older studies relied on single loci, recent publications have used complete genome sequences to estimate divergence. Although still dependent on assumptions of the model used, most recent estimates using the molecular clock give dates of approximately 5–8 million years ago for the human–chimpanzee divergence, in general agreement with the palaeontological evidence.

Key Concepts:

The molecular clock hypothesis proposes that nucleotide changes occur at a regular rate during evolution.

Applying the molecular clock to sequence divergence among living species can provide an estimate of the time of the divergence of these species.

The conversion from sequence divergence to units of geologic time usually requires calibration from the fossil record, although fossil‐free estimates have also been used.

The first appearance in the fossil record of a given lineage provides a minimum age of divergence of taxa that created that lineage, not a point estimate of the divergence.

Confidence in the fossil calibration is dependent on the completeness of the fossil record.

Estimates of the human–chimpanzee divergence using the molecular clock have ranged from less than 3 million to nearly 12 million years ago (Ma).

Most reliable estimates of the human–chimpanzee divergence range from 5 to 8 Ma.

Considering the various sources of uncertainty associated with molecular dating, in general the dates are in agreement with palaeontological data.
The Evolution of Animal Personality Variation
Authors: Kight Caitlin R , David Morgan , Dall Sasha RX 
Published: May 2013

AbstractIn many species of animals individual behaviour differs, yet is consistent over time and in an array of different environments; in other words, these animals display ‘personality’ variation. This may emerge not by chance, but, instead, is shaped by selective processes favouring individuals who display a differentiated behavioural phenotype. Indeed, personalities are known to affect important activities such as resource acquisition, survival and reproduction – which, cumulatively, impact an individual's fitness. We currently lack the insights and technology needed to fully characterise the genetics and physiology of most ecologically relevant behaviour; however, much can be gained by adopting an adaptive approach to consider the evolutionary processes that might have driven the emergence and maintenance of stable behavioural variation. Such an exercise will allow us to developa priorihypotheses about the mechanisms underlying the behaviour, and to conduct powerful empirical studies examining how individualised behaviour impacts the life histories of a variety of species.Key Concepts:In many animal species, individuals differ predictably in their behaviour; this consistent behavioural variation is often referred to as ‘animal personalities’ (or ‘behavioural types’, ‘coping styles’, ‘temperament’ and ‘behavioural syndromes’).Expression of personalities can have significant impacts on activities such as resource acquisition, survival and reproduction – and, therefore, may influence fitness.A variety of factors may contribute for interindividual variation within populations; these include mutation, stochasticity, strong tradeoffs, spatiotemporal fluctuations, condition dependence and state dependence and negative frequency dependence.Personalities can also be thought of as individual behavioural specialisation; this may arise as a result of life history tradeoffs, state‐dependent feedback, adaptive packaging of suites of traits and adaptive consistency.Certain personalities may not be beneficial under some circumstances; however, when their effects are considered across the range of different circumstances that an animal will experience throughout its lifetime, these personalities will ultimately prove beneficial – otherwise they will not be maintained in the population.The study of animal behaviour is useful for generating testable hypotheses about how genetics and physiology may underpin ecologically relevant behaviour, as well as for predicting the exact mechanisms that might link these traits.
Human Genetics of Osteoarthritis
Authors: Valdes Ana M 
Published: May 2013

Abstract

Osteoarthritis (OA) has an important genetic contribution. Genetic studies in humans have identified molecules involved in signalling cascades that are important for the pathology of the joint components such as the bone morphogenetic protein growth differentiation factor 5. Genome‐wide association studies (GWAS) in Asians have uncovered a likely role for structural extracellular matrix components (double von Willebrand factor type A domain) and molecules involved in immune response, but these genes are not associated in Caucasian patients. In Caucasians, a number of OA susceptibility signals that have surpassed the genome‐wide significance level (
p
=5×10
−8
) have been identified. A locus on chr7q22 near the orphan receptor GPR22 was discovered from GWAS for knee OA. An analysis using a 1000‐genomes project‐based imputation identified a variant mapping near the MCF2L gene. GWA and functional studies revealed that the DOT1L gene on 19q13 is also associated with hip OA and cartilage thickness. Finally, a recent GWAS in the UK subjects revealed 8 more loci that increase risk for knee or hip OA.

Key Concepts:

Osteoarthritis has an important genetic contribution which has been explored in humans using linkage and genetic association studies.

Genome‐wide association studies and candidate gene studies have identified several consistent associations with large joint (hip and knee OA) and highlighted the complex genetics to this disease, with many genes contributing modestly to overall disease risk.

This genetic contribution to OA form has now been estimated to be in the order of 39–65%.

Some of the genes to come out from genetic association studies appear to relate to skeletal development mediated by bone morphogenetic proteins (GDF5) and Wnt signalling (DOT1L) genes as well as genes known to be related to cartilage metabolism (CHST11).

The functional role of many of the genes identified so far still remains to be elucidated.
Do perceived social stress and resilience influence the effects of psychopathy‐linked narcissism and CU traits on adolescent aggression?
Authors: Kauten Rebecca , Barry Christopher T. , Leachman Lacey 
Published: May 2013

AbstractThe current study explored the influences of social stress and resilience on the relation between psychopathy‐linked personality characteristics (i.e., narcissism, dimensions of CU traits) and aggression with the expectation that social stress would exacerbate the relation, whereas resilience would mitigate it. In a sample of 154 at‐risk adolescents (ages 16–18; 84% male), contrary to expectations, high social stress attenuated the relations of narcissism and callousness with aggression. Self‐reported resilience attenuated the relation between callousness and aggression. The implications for understanding the role that these moderators might play in the association between adolescent psychopathic tendencies, particularly callousness, and aggression are discussed. Aggr. Behav. 39:381–390, 2013. © 2013 Wiley Periodicals, Inc.
Surface Nanoarchitecture for Bio‐Applications: Self‐Regulating Intelligent Interfaces
Authors: Skorb Ekaterina V. , Andreeva Daria V. 
Published: May 2013

AbstractThe surface nanoarchitecture provides spatially and temporally resolved stimuli response of the material, and offers defined control over the behavior of biomolecules and cells at the solid‐liquid interface. Here, the focus is on metal‐based systems that are interesting for biomedical applications. Intelligence of the surface is suggested to be achieved through its nanostructuring for stimuli responsive properties. Spatial and temporal cell performance at the surface, provided by the surface nanoarchitecture, offers advanced bio‐applications of metal‐based materials, such as implantation, lab‐on‐chip and organ‐on‐chip, biosensors, smart biomaterials and drug delivery systems. Spatial control is achieved by surface patterning. Temporal control is accessed through the application of stimuli responsive switchable surface chemistry, sensitive to external parameters: temperature, pH, light, electric and magnetic field, ionic strength, surrounding medium (hydrogels in water), multi‐trigger response, and response to products of the cell metabolism. The key issue is the prospect in the formation of self‐regulating “intelligent” surface cell interactions: biomimetic of natural systems.
Organocatalytic Asymmetric Mannich Reactions of 5H‐Oxazol‐4‐ones: Highly Enantio‐ and Diastereoselective Synthesis of Chiral α‐Alkylisoserine Derivatives
Authors: Han Zhiqiang , Yang Wenguo , Tan Choon‐Hong , Jiang Zhiyong 
Published: May 2013

AbstractThe first organocatalytic Mannich reaction of 5H‐oxazol‐4‐ones with various readily prepared aryl‐ and alkylsulfonimides has been developed. Two commercially available pseudoenantiomeric Cinchona alkaloids‐derived tertiary amine/ureas have been demonstrated as the most efficient catalysts to access the opposite enantiomers of the Mannich products with equally excellent enantio‐ and diastereoselectivities. From the Mannich adducts, important α‐methyl‐α‐hydroxy‐β‐amino acid derivatives, such as the α‐methylated C‐13 side chain of taxol and taxotere, can be conveniently prepared.
Synthesis of Glutamic Acid and Highly Functionalized Pyrrolidine Derivatives by Utilizing Tunable Calcium Catalysts for Chemoselective Asymmetric 1,4‐Addition and [3+2] Cycloaddition Reactions
Authors: Hut'ka Martin , Tsubogo Tetsu , Kobayashi Shū 
Published: May 2013

AbstractA current trend in organic chemistry is the development of highly efficient, environmentally friendly and inexpensive catalysts for asymmetric transformations. Alkaline earth metals, due to their specific chemical properties and abundance in nature, provide promising and challenging catalysts in organic synthesis. This article describes the utilization of alkaline earth metals in the development of an effective catalytic system based on calcium salts in combination with Box‐type ligands. We disclose asymmetric 1,4‐addition and [3+2] cycloaddition reactions using simple catalytic systems consisting of calcium chloride dihydrate, chiral ligands and tetramethylguanidine. Various Box ligands were synthesized and the most effective proved to be that bearing an indane chiral backbone and a cyano group. Depending on the structure of both glycine Schiff bases and α,β‐unsaturated compounds, the corresponding Michael adducts or pyrrolidine derivatives were obtained in moderate to high yields with high enantioselectivities. Modification of the catalytic system by using more Lewis acidic calcium salts such as calcium triflate and neutral Pybox‐type ligands allows a tuning of the chemoselectivity and leads to suppression of the [3+2] cycloadition reactions. Various β‐substituted acrylates provided 1,4‐addition adducts exclusively in high yields with moderate to high diastereo‐ and enantioselectivities. This methodology has broadened a synthetic route to β‐branched glutamic acid derivatives and established calcium salts as useful and attractive catalysts for asymmetric catalysis.
Frequency of different human mollicutes species in the mucosa of the oropharynx, conjunctiva, and genitalia of free‐ranging and captive capuchin monkeys (Cebus spp.)
Authors: Neto Renata L. , Marques Lucas M. , Guimarães Ana Márcia S. , Yamaguti Mauricio , Oliveira Rosangela C. , Gaetti‐Jardim Jr Elerson , Medina Aziz O. , Sanfilippo Luis F. , Timenetsky Jorge 
Published: May 2013

AbstractThis study is the first to evaluate the occurrence of several Mollicutes species in Brazilian capuchin monkeys (Cebus spp.). Mollicutes were detected by culture and polymerase chain reaction (PCR) in samples of the oropharyngeal, conjuctiva, and genital mucosae of 58 monkeys. In the oropharynx, Mollicutes in general (generic PCR to the Class), and those of the genus Ureaplasma (genus PCR), were detected in 72.4% and 43.0% of the samples, respectively. The identified species in this site included: Mycoplasma arginini (43.1%), M. salivarium (41.4%), and M. pneumoniae (19.0%). Both Ureaplasma and Mycoplasma are genera of the order Mycoplasmatales. In the preputial/vaginal mucosa, PCR detected Mollicutes in general in 27.58% of the samples, the genus Ureaplasma in 32.7%, the species M. arginini in 8.6%, and Acholeplasma laidlawii of the order Acholeplasmatales in 1.7% In the conjunctiva, Mollicutes in general were detected in 29.3% of the samples, with 1.7% being identified as A. laidlawii. Culturing was difficult due to contamination, but two isolates were successfully obtained. The Mollicutes species of this study provided new insights into these bacteria in Brazilian Cebus. Studies are lacking of the actual risk of Mollicutes infection or the frequency at which primates serve as permanent or temporary reservoirs for Mollicutes. In the present study, the samples were collected from monkeys without clinical signs of infection. The mere presence of Mollicutes, particularly those also found in humans, nevertheless signals a need for studies to evaluate the impact of these microorganisms on the health of non‐human primates (NHPs) and the possibility of cross‐species transmission between NHPs and humans. Am. J. Primatol. 75:973–978, 2013. © 2013 Wiley Periodicals, Inc.
Spray and packed liquid–liquid extraction columns: drop size and dispersed phase mass transfer
Authors: Salimi‐Khorshidi Ali , Abolghasemi Hossein , Khakpay Amir , Kheirjooy Zohreh , Esmaieli Mohamad 
Published: May 2013

ABSTRACTThe effects of holdup on Sauter mean drop diameter, D32, and dispersed phase mass transfer coefficient have been studied in the spray and packed extraction columns. For both columns, two well‐defined regions for the dependence of D32 on holdup were observed. D32 increased and decreased with an increase in holdup at low and high levels of holdup, respectively. Changes in dispersed phase mass transfer coefficient against holdup were shown to be similar to D32 for both columns. Moreover, empirical correlations have been derived to predict D32 and dispersed phase mass transfer coefficient for both columns. It has been shown that the derived correlations are in a good agreement with the experimental data. © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.
Phase‐dependent binary interaction parameters in industrial low‐density polyethylene separators
Authors: Nunes Costa Glória Meyberg , Guerrieri Yuri , Kislansky Simão , Embiruçu Marcelo 
Published: May 2013

ABSTRACTIn the production process of low‐density polyethylene (LDPE), an important step is the flash separation of monomers and other small molecules from the polymer produced. The process is carried out adiabatically in two stages. To improve the performance of thermodynamic models, it is very important to analyze the use of model binary interaction parameters (BIP) dependent on the phase characteristics for each phase (phase‐dependent BIP). In this work the PC‐SAFT (perturbed‐chain statistical associating fluid theory) equation of state (EOS) is applied to the flash simulation of LDPE industrial separators using eight different resins. The main numerical aspects are examined with emphasis on the optimization strategy for the EOS BIP that explicitly characterizes each phase involved separately. The results demonstrate good predictive behavior. As a result of improved and more consistent modeling, a new strategy for optimized operation can be envisaged for the sequence of separators. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2106–2117, 2013
Chitosan‐modified d‐α‐tocopheryl poly(ethylene glycol) 1000 succinate‐b‐poly(ε‐caprolactone‐ran‐glycolide) nanoparticles for the oral chemotherapy of bladder cancer
Authors: Liu Baichuan , Wang Han , Fan Lixin , Qiu Xiaofu , Luo Youhua , Zhou Shenyang , Yang Guosheng 
Published: May 2013

ABSTRACTOral chemotherapy is quickly emerging as an appealing option for cancer patients. It is less stressful because the patient has fewer hospital visits and can still maintain a close relationship with health care professionals. Three kinds of nanoparticles made from commercial poly(ε‐caprolactone) (PCL) and self‐synthesized d‐α‐tocopheryl poly(ethylene glycol) 1000 succinate ‐b‐poly(ε‐caprolactone‐ran‐glycolide) [TPGS‐b‐(PCL‐ran‐PGA)] diblock copolymer were prepared in this study for the oral delivery of antitumor agents, including chitosan‐modified PCL nanoparticles, nonmodified TPGS‐b‐(PCL‐ran‐PGA) nanoparticles, and chitosan‐modified TPGS‐b‐(PCL‐ran‐PGA) nanoparticles. First, the TPGS‐b‐(PCL‐ran‐PGA) diblock copolymer was synthesized and structurally characterized. Chitosan was adopted to extend the retention time at the cell surface and thus increase the chance of nanoparticle uptake by the gastrointestinal mucosa and improve the absorption of drugs after oral administration. The resulting TPGS‐b‐(PCL‐ran‐PGA) nanoparticles were found to be of spherical shape and around 200 nm in diameter with a narrow size distribution. The surface charge of the TPGS‐b‐(PCL‐ran‐PGA) nanoparticles could be reversed from anionic to cationic after surface modification. The chitosan‐modified TPGS‐b‐(PCL‐ran‐PGA) nanoparticles displayed a significantly higher level of cellular uptake compared with the chitosan‐modified PCL nanoparticles and nonmodified TPGS‐b‐(PCL‐ran‐PGA) nanoparticles. In vitro cell viability studies showed the advantages of the chitosan‐modified TPGS‐b‐(PCL‐ran‐PGA) nanoparticles over Taxol in terms of their cytotoxicity against human RT112 cells. In summary, the oral delivery of antitumor agents by chitosan‐modified TPGS‐b‐(PCL‐ran‐PGA) nanoparticles produced results that were promising for the treatment of patients with bladder cancer. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2118–2126, 2013
Synthesis and catalytic activity of polymer‐anchored metal complex for oxidation of cyclohexane
Authors: Sweta  , Chand Shri , Sinha Shishir 
Published: May 2013

ABSTRACTCatalytic oxidation of cyclohexane was investigated over polymer‐anchored Co(II) catalyst prepared by modification of polymer surface by NOx and subsequent functinalization by amination. The catalyst characterized by various techniques, such as elemental analysis, atomic absorption spectroscopy, Fourier transform infrared spectroscopy (FT‐IR), thermo‐gravimetric analysis, and scanning electron microscopy confirmed the modification of polymer surface and bond formation between functionalized resin and metal ion. The oxidation of cyclohexane using molecular oxygen (O2) as an oxidant was studied in the temperature and pressure range of 373–413 K and 1.0–1.4 MPa, respectively. The maximum cyclohexane conversion of 18.4% was obtained at 413 K and 1.2 MPa pressure. Cyclohexanone and cyclohexanol were found as the main reaction products with 93.0% selectivity. No appreciable change in catalytic activity and on product selectivity was observed after the catalyst recycled three times. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2127–2135, 2013
Physiological and molecular aspects of degradation of plant polysaccharides by fungi: What have we learned from Aspergillus?
Authors: Culleton Helena , McKie Vincent , de Vries Ronald P. 
Published: May 2013

AbstractPlant biomass is the most abundant and usable carbon source for many fungal species. Due to its diverse and complex structure, fungi need to produce a large range of enzymes to degrade these polysaccharides into monomeric components. The fine‐tuned production of such diverse enzyme sets requires control through a set of transcriptional regulators. Aspergillus has a strong potential for degrading biomass, thus this genus has become the most widely studied group of filamentous fungi in this area. This review examines Aspergillus as a successful degrader of plant polysaccharides, and reviews its potential in many industries such as biofuel and as a production host of homologous and heterologous proteins.
Realistic paint simulation based on fluidity, diffusion, and absorption
Authors: You Mi , Jang Taekwon , Cha Seunghoon , Kim Jihwan , Noh Junyong 
Published: May 2013

ABSTRACTWe present a new method to create realistic paint simulation, utilizing the characteristics of paint, such as fluidity, diffusion, and absorption. We treat the painting elements separately as pigment, binder, solvent, and paper. Adopting smoothed‐particle hydrodynamics including a consideration of viscoelastic movement, we simulate the fluid motion of the paint and the solvent. To handle the diffusion of the pigment in the solvent, we utilize the mass transfer method. Following Fick's law, the concentration of pigment changes and each pigment particle is diffused to the neighborhood accordingly. As time elapses, the binder and the solvent are absorbed, and for the most part, the pigment remains on the paper. The Lucas–Washburn equation determines the distance of absorption. The examples show that our approach can effectively generate various types of painting. Copyright © 2013 John Wiley & Sons, Ltd.
Classification of human motion based on affective state descriptors
Authors: Cimen Gokcen , Ilhan Hacer , Capin Tolga , Gurcay Hasmet 
Published: May 2013

ABSTRACTHuman body movements and postures carry emotion‐specific information. On the basis of this motivation, the objective of this study is to analyze this information in the spatial and temporal structure of the motion capture data and extract features that are indicative of certain emotions in terms of affective state descriptors. Our contribution comprises identifying the directly or indirectly related descriptors to emotion classification in human motion and conducting a comprehensive analysis of these descriptors (features) that fall into three different categories: posture descriptors, dynamic descriptors, and frequency‐based descriptors in order to measure their performance with respect to predicting the affective state of an input motion. The classification results demonstrate that no single category is sufficient by itself; the best prediction performance is achieved when all categories are combined. Copyright © 2013 John Wiley & Sons, Ltd.