bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation of stress intensity factors in 2‐D linear fracture mechanics by Petrov–Galerkin natural element method
Authors: Cho J. R. , Lee H. W.
Published: April 2014

This paper is concerned with the numerical calculation of stress intensity factors in two‐dimensional linear fracture problems by Petrov–Galerkin natural element method, for which the Voronoi polygon‐based Laplace interpolation functions and constant strain finite element basis functions are taken for the trial and test functions, respectively. A local element patch recovery technique is employed to obtain more accurate smoothed strain and stress fields, and the stress intensity factors of edge and angled center cracks are calculated by both the J‐integral and interaction integral methods. The influence of the grid density, integral domain size, and weighting function type on the numerical accuracy is investigated through the numerical experiments. In addition, the present method is compared with the hybrid crack elements in combination with extended FEM and the scaled boundary FEM. It is confirmed that Petrov–Galerkin natural element method provides the numerical accuracy similar to these recent direct methods. Also, it is found that the accuracy of the J‐integral is affected by the grid density but not by the integral domain size. In the case of the interaction integral, the numerical accuracy is influenced by both the type of weighting function and the integral domain size. Copyright © 2014 John Wiley & Sons, Ltd.
Celebrity altruism: the good, the bad and the ugly in relationships with fundraising charities
Authors: Kelly Sean P. , Morgan Gareth G. , Coule Tracey M.
Published: April 2014

Enlisting or retaining the support of celebrity volunteers is a crucial element in the fundraising and communications strategies for many third sector organisations. But whilst there is a plethora of literature on volunteer motivations, there has been little exploration of the relationships between celebrity volunteers and the charities that they support. Furthermore, the limited theory that exists appears to be based on the experiences of fundraisers and other media specialists with little primary research on attitudes of celebrities themselves. This paper therefore considers celebrity/charity relationships on the basis of existing volunteer motivation theory and attitudinal data from a sample of 208 celebrity volunteers associated with a major fundraising charity in the UK. The findings indicate that the motivation of celebrity volunteers may be much closer to those of other charity volunteers than might be expected from other literature on celebrities. In addition, the study found that amongst other factors, celebrity volunteers typically prefer their engagements to be simplistic and expedient in nature, but that where possible, the engagement activity should be fun and rewarding. It also reveals that individual motives for supporting charities are varied in nature and range from purely altruistic tendencies at one end of the continuum to egoistic motives at the other. In addition, the study indicates that factors such as security and trust in the endorsed organisation are a key motivating factor for many.

Copyright © 2014 John Wiley & Sons, Ltd.
Use of donor‐specified donation splitting: a technique to understand the impact of financial management on donor trust
Authors: Burt Chris , Williams Skye
Published: April 2014

Two experiments investigated donors' willingness to split their donation into a proportion that the charity could use for administration costs and a portion that could be used to deliver the charity's services. Experiment 1 found that participants in the condition given the opportunity to split their donation into an amount for administration costs and an amount for service delivery gave a significantly smaller proportion of their overall donation to administration costs, when compared with participants in another condition who were simply asked what proportion of their donation they would be happy for the organization to use for administration costs. Experiment 2 manipulated the amount of information participants (donors) received about the breakdown of a charity's administration costs but found no significant change in the amount donated to administration. Both experiments show that donors were willing to donate approximately 15% of their donation directly to charity administration costs. Results are discussed in terms of understanding how a charity's financial management might be influencing donor's trust in the charity and providing charities with a degree of certainty in the proportion of donations they can spend on administration costs.

Copyright © 2014 John Wiley & Sons, Ltd.
Grafting of hydroxymethylacrylamide and acrylic acid copolymer onto polyvinylidene fluoride membrane by supercritical carbon dioxide and its application in dye separation
Authors: Hou Minna , Cao Liqin , Wang Jide , Lin Jiangli , Zhao Mengqi , Wang Gang
Published: April 2014

We report a thermally induced graft copolymerization of acrylic acid and N‐hydroxymethylacrylamide onto polyvinylidene fluoride microporous membrane by using supercritical carbon dioxide as a solvent and carrier agent. The effects of monomer mole ratio, pressure, reaction temperature, time, and initiator concentration on the degree of grafting were investigated. The morphology of the grafted membrane was studied via scanning electron microscopy. Attenuated total reflectance infrared spectroscopy spectroscopy and X‐ray diffraction proved the existence of grafting monomers. The results of contact angle measurement and water filtration at different pH levels indicated pronounced pH‐sensitive behavior and increased hydrophilicity of the polyvinylidene fluoride grafted membrane. In particular, the grafted membrane was applied to the removal of methylene blue with a relative rejection of 98.1% compared with 30.5% of rejection observed from the pristine polyvinylidene fluoride membrane. Copyright © 2014 John Wiley & Sons, Ltd.
Five years in vitro study of (poly vinyl alcohol/poly vinyl pyrrolidone/poly acrylic acid) hydrogel to mimic the knee joint meniscus
Authors: Awadallah‐F Ahmed
Published: April 2014

In this in vitro study, the developing of novel hydrogels to be used as artificial knee meniscus proceeded for 5 years. These hydrogels were synthesized from polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP)/poly acrylic acid (PAAc) via using irradiation of γ‐rays. Further, the effects of composition, concentration and irradiation dose were investigated. Functional groups and surface morphologies of synthesized hydrogels were characterized by Fourier transform infra red (FTIR) and scanning electron microscopy (SEM). The swelling (%), gelation (%), mass stability (%) and the mechanical tests for compression and stress–relaxation were studied. Factorial design was also used to investigate the relative significance of synthesis factors on the hydrogel properties such swelling, gelation and yield stress. The mechanical tests of PVA/PVP/PAAc hydrogel showed that the yield stress is similar to human meniscus. Therefore, the results suggest that it is possible to use PVA/PVP/PAAc hydrogel to compensate for knee meniscus function. Copyright © 2014 John Wiley & Sons, Ltd.
Monodimensional (GC–FID and GC–MS) and Comprehensive Two‐dimensional Gas Chromatography for the Assessment of Volatiles and Fatty Acids from Ruta chalepensis Aerial Parts
Authors: Tedone Laura , Costa Rosaria , De Grazia Selenia , Ragusa Salvatore , Mondello Luigi
Published: April 2014

Introduction

Ruta chalepensis L. (Rutaceae) is widespread in the Mediterranean area. This plant has a solid tradition in ethnomedicine because of its various biological activities. Based on previous reports, the main volatile constituents of R. chalepensis are 2‐undecanone and 2‐nonanone, but most are still unknown, particularly fatty acid composition.

Objective

To exhaustively characterise the chemical composition of the aerial parts from R. chalepensis plants collected from the wild in Sicily, within a project aiming at the evaluation and characterisation of medicinal plants from the Mediterranean flora. The study was directed toward the determination of volatiles and fatty acids in samples of R. chalepensis obtained from different aerial plant parts and from plants harvested at different times.

Methods

GC with flame ionisation detection, GC–MS and two‐dimensional gas chromatography (GC × GC) advanced techniques, with support of dedicated mass spectral databases provided with retention index (RI) information, were applied to determine both volatiles and fatty acids. Samples were extracted by hydrodistillation and underwent methylic transesterification in order to be transformed into the correspondent fatty acid methyl esters (FAMEs).

Results

The monodimensional analysis by GC–MS with RI confirmed that 2‐nonanone and 2‐undecanone are the predominant components in all the plant parts, followed by esters and monoterpenes. A different distribution was observed of the main compounds in the various plant parts depending on the life cycle of the plant (vegetative or reproductive stage). The multidimensional GC × GC analysis allowed for a complete screening of the fatty acids. About 65% of the total were polyunsaturated fatty acids (PUFA), followed by 30% of saturated fatty acids (SFA).

Conclusion

A detailed GC volatile fingerprint of R. chalepensis flowers, leaves, fruits and stems was established, highlighting the compositional differences depending on plant organs and life cycle. The results indicated R. chalepensis as a good source of fatty acids from the w3 and w6 series. In both essential oil and lipidic extract, many compounds were determined for the first time. Copyright © 2014 John Wiley & Sons, Ltd.
Accelerated brush growth on nanoparticle surfaces by reversible addition‐fragmentation chain transfer polymerization
Authors: Jiao Yang , Akcora Pinar
Published: April 2014

It is now well established that controlling the grafted chain lengths and densities on nanoparticle surfaces determines the effective interactions between particles, and their assembly. Here, we present unusual kinetic results for achieving grafted chain lengths longer than the free chains using reversible addition‐fragmentation chain transfer (RAFT) polymerization and discuss the limitations to obtaining polymer grafting density higher than ∼0.06 chains/nm2. We observe that surface initiated polymerization grows faster than the free chains in solution with high RAFT agent coverage (1.95 agents/nm2) on nanoparticles. The time‐dependence of graft density suggests that activation of the anchored chain transfer agent (CTA) is limited by the diffusion of macro‐radicals within growing grafts. Thus, radical transfer and exchange reactions become inefficient between grafts and free polymer, and convert the surface‐initiated RAFT mechanism to a free radical polymerization. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1700–1705
Synthesis of methallylic monomers bearing ammonium side‐groups and their radical copolymerization with chlorotrifluoroethylene
Authors: Alaaeddine Ali , Boschet Frédéric , Ameduri Bruno
Published: April 2014

Methallylic monomers bearing triethyl or 4‐diazabicyclo[2.2.2]octane (DABCO) ammonium side‐groups are prepared and copolymerized with chlorotrifluoroethylene (CTFE). First, three different monomers are synthesized from chloro‐2‐methylprop‐1‐ene or 3‐chloro‐2‐chloromethylprop‐1‐ene in fair to good yields (57–95%). Then, several parameters (initiators, aqueous or solution processes, temperature) of the radical copolymerization of these monomers with chlorotrifluoroethylene are investigated. Various initiators are tested in the presence of ammonium perfluorooctanoate (APFO) as water‐soluble surfactant, and tert‐butyl peroxypivalate/APFO leads to the best results in a mixed solvent (H2O/CH3CN/C4F5H5). In all experiments, the radical copolymerization shows that CTFE is more reactive than the methallylic monomer as evidenced by the characterization of poly(CTFE‐co‐M) copolymer by nuclear magnetic resonance spectroscopy and elemental analysis. Thermal degradation of these copolymers by thermogravimetric analyses indicates that the copolymers are stable up to 180 °C without any degradation and have a Td,10% above 300 °C. Finally, their ionic exchange capacities range between 0.94 and 1.69 meq g−1. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1721–1729
Ligand Exchange on Gold Nanorods: Going Back to the Future
Authors: Indrasekara A. Swarnapali D. S. , Wadams Robert C. , Fabris Laura
Published: April 2014

Ligand exchange on gold nanorods (NRs) is still too often dismissed or not given the importance it should deserve. The many applications of gold NRs, mainly in plasmonics, biological imaging, and sensing, are made possible by finely tuning not only the optical properties of the metallic core but also the tethered functional groups. Gold NRs are mainly synthesized by using CTAB as the morphology‐guiding surfactant, and an intimate relationship between the crystallographic facets of the rod and the CTAB bilayer exists. Because of this, it is imperative to fully understand the ligand exchange mechanisms that allow replacing CTAB with functional ligands, including the energetic contributions. Here, the major applications of gold NRs are briefly overviewed, and what is known about ligand exchange mechanisms is summarized, as well as why it is important to achieve complete removal of CTAB, including the techniques that are used to characterize the exchange reaction products. The concept of interface in gold NRs is briefly examined, and explained why the scientific community should focus more on understanding and characterizing it. Starting from the published literature, the reader is guided through the reasons why it is thought that ligand exchange on gold NRs is perhaps the next grand challenge in the nanoparticle field.
Risk factors for the development of pleural empyema in children
Authors: Elemraid Mohamed A. , Thomas Matthew F. , Blain Alasdair P. , Rushton Stephen P. , Spencer David A. , Gennery Andrew R. , Clark Julia E. ,   On behalf of the North East of England Pediatric Respiratory Infection Study Group Newcastle upon Tyne, UK
Published: April 2014

Pediatric pleural empyema has increased substantially over the past 20 years and reasons for this rise remain not fully explained. We investigated potential risk factors for the development of empyema in children by examining a cohort of patients with community‐acquired pneumonia. Demographic, clinical, and socioeconomic characteristics, use of Ibuprofen prior to presentation and selected potential epidemiological risk factors were analyzed. Data were collected from a prospective etiological study of radiologically confirmed pneumonia in hospitalized children aged ≤16 years. One hundred sixty children were enrolled; 56% were male and 69% aged <5 years. Empyema complication developed in 40 (25%) children. Children with empyema were more frequently prescribed Ibuprofen prior to admission to hospital than those without (82% vs. 46.2%; OR 1.94, 97.5% credible interval 0.80–3.18). Bacterial infection was strongly associated with the development of empyema (OR 3.34, 97.5% credible interval 1.70–5.14). In contrast age, sex, maternal age, parental smoking, level of socioeconomic status, nursery attendance, asthma, household characteristics (bedrooms and number of occupants) were not significantly different between groups. In conclusion, children with pneumonia who developed empyema had more often received Ibuprofen prior to hospitalization and confirmed bacterial infection. We suggest a population‐based study involving both primary and secondary care settings would help to investigate the role of Ibuprofen use in modulating the course of disease in children with pneumonia. Pediatr Pulmonol. 2015; 50:721–726. © 2014 The Authors. Pediatric Pulmonology Published by Wiley Periodicals, Inc.
Interleukin‐17 promotes development of castration‐resistant prostate cancer potentially through creating an immunotolerant and pro‐angiogenic tumor microenvironment
Authors: Zhang Qiuyang , Liu Sen , Zhang Qingsong , Xiong Zhenggang , Wang Alun R. , Myers Leann , Melamed Jonathan , Tang Wendell W. , You Zongbing
Published: April 2014

BACKGROUND

Interleukin‐17 (IL‐17) has been demonstrated to promote formation and growth of hormone‐naïve prostate adenocarcinoma in mice. IL‐17's role in development of castration‐resistant prostate cancer is unknown. In the present study, we investigated IL‐17's role in castration‐resistant prostate cancer in a mouse model.

METHODS

IL‐17 receptor C (IL‐17RC) deficient mice were interbred with Pten conditional mutant mice to produce RC+ mice that maintained IL‐17RC expression and RC− mice that were IL‐17RC deficient. Male RC+ and RC− mice were Pten‐null and were castrated at 16 weeks of age when invasive prostate cancer had already formed. At 30 weeks of age, all male mice were analyzed for the prostate phenotypes.

RESULTS

RC− mice displayed prostates that were smaller than RC+ mice. Approximately 23% of prostatic glands in RC− mice, in contrast to 65% of prostatic glands in RC+ mice, developed invasive adenocarcinomas. Compared to castrate RC+ mice, castrate RC− mouse prostate had lower rates of cellular proliferation and higher rates of apoptosis as well as lower levels of MMP7, YBX1, MTA1, and UBE2C proteins. In addition, castrate RC− mouse prostate had less angiogenesis, which was associated with decreased levels of COX‐2 and VEGF. Moreover, castrate RC− mouse prostate had fewer inflammatory cells including lymphocytes, myeloid‐derived suppressor cells, and macrophages.

CONCLUSIONS

Taken together, our findings suggest that IL‐17 promotes development of invasive prostate adenocarcinomas under castrate conditions, potentially through creating an immunotolerant and pro‐angiogenic tumor microenvironment. Prostate 74:869–879, 2014. © 2014 Wiley Periodicals, Inc.
IMPACTS OF DROUGHT AND CRAYFISH INVASION ON STREAM ECOSYSTEM STRUCTURE AND FUNCTION
Authors: Magoulick D. D.
Published: April 2014

Drought and seasonal drying can be important disturbance events in many small streams, leading to intermittent or isolated habitats. Many small streams contain crayfish populations that are often keystone or dominant species in these systems. I conducted an experiment in stream mesocosms to examine the effects of drought and potential ecological redundancy of a native and invasive crayfish species. I examined the effects of drought (drought or control) and crayfish presence (none, native crayfish Orconectes eupunctus or invasive crayfish Orconectes neglectus) on stream mesocosm structure and function (leaf breakdown, community metabolism, periphyton, sediment and chironomid densities) in a fully factorial design. Each mesocosm contained a deep and shallow section, and drought treatments had surface water present (5‐cm depth) in deep sections where tiles and leaf packs were placed. Drought and crayfish presence did not interact for any response variable. Drought significantly reduced leaf breakdown, and crayfish presence significantly increased leaf breakdown. However, the native and invasive crayfish species did not differ significantly in their effects on leaf breakdown. Drought significantly reduced primary production and community respiration overall, whereas crayfish presence did not significantly affect primary production and community respiration. Neither drought nor crayfish presence significantly affected periphyton overall. However, drought significantly reduced autotrophic index (AI), and crayfish presence increased AI. Inorganic sediment and chironomid density were not affected by drought, but both were significantly reduced by crayfish presence. O. eupunctus reduced AI and sediment more than O. neglectus did. Neither drought nor crayfish species significantly affected crayfish growth or survival. Drought can have strong effects on ecosystem function, but weaker effects on benthic structure. Crayfish can have strong effects on ecosystem structure and function regardless of drought. In stream mesocosms, native and invasive crayfish species appeared largely ecologically redundant, although subtle differences in crayfish effects could cascade throughout the food web, and further research is needed to address this question. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Plasma im Beutel
Authors: Thomas Michael , Lachmann Kristina
Published: April 2014

„Plasma im Beutel”︁ beschreibt ein neues kostengünstiges Verfahren zur Innenbeschichtung von geschlossenen Kunststoffbeuteln mittels Atmosphärendruckplasma. Mit dem Verfahren können homogene, langzeitstabile funktionelle Schichten auf der Innenseite von Zellkulturbeuteln aufgebracht werden. Die Flächendichte der funktionellen Aminogruppen wurde durch chemische Derivatisierung in Kombination mit ATR‐FTIR‐Spektroskopie nachgewiesen. Durch den Aufbau eines ersten Anlagenprototypen konnten unter normalen Laborbedingungen automatisiert und reproduzierbar Schichten abgeschieden werden, ohne die Sterilität der Beutel negativ zu beeinflussen. In den beschichteten Beuteln konnten auch nach längeren Lagerzeiten humane mesenchymale Stammzellen mit hohen Ausbeuten adhärent gezüchtet werden. Durch die Wahl des Schichtbildners bei der Plasmabehandlung können Schichten mit verschiedenen chemischen Funktionalitäten abgeschieden werden. Zukünftige Ziele sind die Abscheidung von Migrationsbarrieren sowie die Beschichtung von Flaschen mit hydrophoben Oberflächen.
Cognitive ecology: ecological factors, life‐styles, and cognition
Authors: Mettke‐Hofmann Claudia
Published: April 2014

Cognitive ecology integrates cognition, ecology, and neurobiology in one topic and has recently broadened into an exciting diversity of themes covering the entire range of cognition and ecological conditions. The review identifies three major environmental factors interacting with cognition: environmental variation (predictable and unpredictable), environmental complexity and predation. Generally, variable environments favor cognitive abilities such as exploration, learning, innovation, memory and also result in larger brains as compared to stable environments. Likewise, cognition is enhanced in complex versus simple environments, whereas the relationship between predation and cognitive abilities can be positive or negative. However, organisms have often evolved entire life‐styles (e.g., residency versus migration, food‐caching versus noncaching, generalism versus specialism) to deal with these environmental factors. Considering cognition within this framework provides a much more diverse picture of how cognitive abilities evolved in conjunction with other adaptations to environmental challenges. This integrated approach identifies gaps of knowledge and allows the formulation of hypotheses for future testing. Several recently emerged approaches study cognitive abilities at a new and in part highly integrated level. For example, the effect that environment has on the development of cognitive abilities during ontogeny will improve our understanding about cause and effect and gene–environment interactions. Together with two recently emerged highly integrative approaches that link personality and pace‐of‐life syndromes with cognitive ecology these new directions will improve insight how cognition is interlinked with other major organizational processes.

This article is categorized under:

Cognitive Biology > Evolutionary Roots of Cognition

Psychology > Learning

Neuroscience > Cognition
Degradation of oligouridylated histone mRNAs: see UUUUU and goodbye
Authors: Hoefig Kai P. , Heissmeyer Vigo
Published: April 2014

During the cell cycle the expression of replication‐dependent histones is tightly coupled to DNA synthesis. Histone messenger RNA (mRNA) levels strongly increase during early S‐phase and rapidly decrease at the end of it. Here, we review the degradation of replication‐dependent histone mRNAs, a paradigm of post‐transcriptional gene regulation, in the context of processing, translation, and oligouridylation. Replication‐dependent histone transcripts are characterized by the absence of introns and by the presence of a stem‐loop structure at the 3′ end of a very short 3′ untranslated region (UTR). These features, together with a need for active translation, are a prerequisite for their rapid decay. The degradation is induced by 3′ end additions of untemplated uridines, performed by terminal uridyl transferases. Such 3′ oligouridylated transcripts are preferentially bound by the heteroheptameric LSM1‐7 complex, which also interacts with the 3′→5′ exonuclease ERI1 (also called 3′hExo). Presumably in cooperation with LSM1‐7 and aided by the helicase UPF1, ERI1 degrades through the stem‐loop of oligouridylated histone mRNAs in repeated rounds of partial degradation and reoligouridylation. Although histone mRNA decay is now known in some detail, important questions remain open: How is ceasing nuclear DNA replication relayed to the cytoplasmic histone mRNA degradation? Why is translation important for this process? Recent research on factors such as SLIP1, DBP5, eIF3, CTIF, CBP80/20, and ERI1 has provided new insights into the 3′ end formation, the nuclear export, and the translation of histone mRNAs. We discuss how these results fit with the preparation of histone mRNAs for degradation, which starts as early as these transcripts are generated. WIREs RNA 2014, 5:577–589. doi: 10.1002/wrna.1232

This article is categorized under:

RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications

RNA Processing > 3' End Processing

RNA Turnover and Surveillance > Regulation of RNA Stability
Reflecting Resiliency: Openness About Sexual Orientation and/or Gender Identity and Its Relationship to Well‐Being and Educational Outcomes for LGBT Students
Authors: Kosciw Joseph G. , Palmer Neal A. , Kull Ryan M.
Published: April 2014

For lesbian, gay, bisexual, and transgender (LGBT) youth, coming out (i.e., disclosure of LGBT identity to others) can be a key developmental milestone, one that is associated with better psychological well‐being. However, this greater visibility may come with increased risk of peer victimization. Being out, therefore, may reflect resilience and may unfold differently depending on ecological context as some spaces may be more or less supportive of LGBT youth than others. This article explores a model of risk and resilience for outness among LGBT youth, including whether it varies by community context. We tested our hypothesized model with a national dataset of 7,816 LGBT secondary school students using multi‐group structural equation modeling. Consistent with our hypotheses, outness was related to higher victimization but also to higher self‐esteem and lower depression. Greater victimization was related to negative academic outcomes directly and indirectly via diminished well‐being. The increases in victimization associated with outness were larger for rural youth, and benefits to well‐being partly compensated for their lower well‐being overall. This article suggests that being out reflects resilience in the face of higher risk of victimization, in addition to promoting well‐being in other ways. Nonetheless, contextual factors influence how this model operates among LGBT youth.
Origins of the FIGO initiative to reduce the burden of unsafe abortion
Authors: Shaw Dorothy
Published: April 2014

The origins of the International Federation of Gynecology and Obstetrics (FIGO) Initiative for the Prevention of Unsafe Abortion and its Consequences began in 1969 when a young British medical student encountered a young woman in Canada with complications of unsafe abortion. Through evolving understanding of the context of women's lives, including the role of family planning and access to safe abortion globally in preventing the deaths and imprisonment of women, I was able to contribute to FIGO's advocacy through a collaborative initiative with country‐led action plans based on a situational analysis. Forty‐six member associations rapidly agreed to participate with results of situational analyses—an unprecedented result in FIGO's history. Professor Anibal Faúndes’ role has been pivotal to the success of this initiative, including the establishment of a working group of regional coordinators and collaborating agencies to oversee the implementation of action plans involving in‐country partners and the Ministry of Health. Deaths from unsafe abortion and its complications are preventable.
Value of conventional cytology in the presence of macroscopic lesions of the anal canal
Authors: Barcellos Lêda Pereira de , Russomano Fábio , Coutinho José Ricardo Hildebrandt
Published: April 2014

Objectives To verify the value of conventional cytology for the diagnosis of macroscopic lesions of the anal canal and to describe the limitations of the samples.

Method We evaluated 395 conventional cytology samples obtained by brushing the anal canal of patients (predominantly male, HIV-positive) and compared them to the presence of macroscopic lesions of the anal canal observed under anorectal examination.

Results Of the total, 91.6% of samples were classified as adequate. Cellular elements representative of the anal transformation zone were observed in 63.5% of samples. Sensitivity in the presence or absence of cellularity was 80% and 31%, respectively.

Conclusion The study demonstrates the feasibility of using conventional anal cytology in outpatients.
The Playground of Europe
Authors: Stephen Leslie
Published: April 2014

Author and mountaineer Sir Leslie Stephen (1832–1904) developed a passion for the Alps following his first trip to the Bavarian Tyrol in 1855. He went on to achieve several first ascents of Alpine peaks, earning him a reputation as one of the foremost alpinists in Britain. An intrepid climber and gifted writer, Stephen embodied a new trend of mountaineering, of a more athletic nature, and his vivid and lyrical descriptions of his experiences in these mountains have an almost poetic quality to them, testifying to the heights of his enthusiasm. First published in 1871 to commemorate his first ascents, this collection of articles quickly became a classic of mountaineering literature. The present work is a reissue of the 1894 edition, which was substantially revised by the author. It remains a charming and informative group of essays which will appeal to readers interested in the history of alpinism.
From Shakespeare to Pope
Authors: Gosse Edmund
Published: April 2014

Edmund Gosse (1849–1928), best known for his memoir Father and Son, was one of the foremost literary critics of his day, even though he had not received a university education. Invited to give the prestigious Clark Lectures at Cambridge, he developed the materials for this book, first published in 1885. Gosse sets out his theory of classical poetry, analysing its rise in the seventeenth century in opposition to freer, more romantic blank-verse forms. The book became the subject of a famously excoriating forty-page review by Oxford-educated critic John Churton Collins. While Collins' estimation of the inaccuracies in Gosse's work was largely correct, the review went far beyond constructive appraisal and caused a literary scandal, though Gosse's reputation was not permanently damaged. This book and the controversy it caused form part of the story of English literature as it established itself as a professional academic discipline.
Elements of Chinese Grammar
Authors: Marshman Joshua
Published: April 2014

Chinese, in its various forms, is spoken today by over a billion people, making it the most spoken language in the world. A member of the Sino-Tibetan family, it is a tone language with an analytic structure. First published in 1814, this grammar of colloquial Chinese was compiled by the Christian missionary Joshua Marshman (1768–1837), who was inspired to do so after preparing a Chinese translation of the Bible. It begins with a preliminary essay outlining the characters of Chinese, its tones, its system of monosyllables and its relationship to neighbouring languages. The grammar itself is extensive, covering all aspects of the language's structure, including case, agreement, pronouns, verbs, mood, tense, prosody, parts of speech and dialect variation. Illustrated with numerous examples and explaining each grammatical concept in detail, this work remains useful and relevant in historical linguistics.
Motion and coalescence of sessile drops driven by substrate wetting gradient and external flow
Authors: Ahmadlouydarab Majid , Feng James J.
Published: April 2014

We report two-dimensional simulations of drop dynamics on a substrate subject to a wetting gradient and an external pressure gradient along the substrate. A phase-field formulation is used to represent the drop interface, and the moving contact line is modelled by Cahn–Hilliard diffusion. The Navier–Stokes–Cahn–Hilliard equations are solved by finite elements on an adaptively refined unstructured grid. For a single drop and a pair of drops, we consider three scenarios of drop motion driven by the wetting gradient only, by the external flow only, and by a combination of the two. Both the capillary force and the hydrodynamic drag depend strongly on the shape of the drop. Since the drop adapts its shape to the local wetting angles and to the external flow on a finite time scale, hysteresis is a prominent feature of the drop dynamics under opposing forces. For each wetting gradient, there is a narrow range of the magnitude of the external flow within which a single drop can achieve a stationary state. The equilibrium drop shape and position depend on its initial shape and the history of forcing. For a pair of drops, the wetting gradient or external flow alone tends to produce catch-up and coalescence. The flow-driven coalescence arises from a viscous shielding effect that relies on the asymmetric shape of the trailing drop once it is deformed by flow. This mechanism operates at zero Reynolds number, but is much enhanced by inertia. With the two forces opposing each other, the external flow favours separation while the wetting gradient favours coalescence. The outcome depends on their competition.
ISLAM IN AFRICA/AFRICANS AND ISLAM
Authors: Reese Scott S.
Published: April 2014

This essay discusses some of the recent trends in the scholarship on Islam and Africa that contribute to a more nuanced understanding of the historical relationship between African Muslims and the globalecumeneof believers. Rather than looking at the faith as an insular African phenomenon, this piece examines the links between Africans and the wider community of believers across space and time. Such an approach has important ramifications for our understanding of the dynamics of Islam. However, it also challenges many of the assumptions underpinning the geographic area studies paradigm that has dominated the academy since the Second World War. This essay suggests the adoption of a more fluid approach to scholarly inquiry that reimagines our largely continental attachment to regions in favor of a more intellectually agile methodology where the scope of inquiry is determined less by geographic boundaries and more by the questions we seek to answer.
Local path planning for mobile robots based on intermediate objectives
Authors: Ma Yingchong , Zheng Gang , Perruquetti Wilfrid , Qiu Zhaopeng
Published: April 2014

This paper presents a path planning algorithm for autonomous navigation of non-holonomic mobile robots in complex environments. The irregular contour of obstacles is represented by segments. The goal of the robot is to move towards a known target while avoiding obstacles. The velocity constraints, robot kinematic model and non-holonomic constraint are considered in the problem. The optimal path planning problem is formulated as a constrained receding horizon planning problem and the trajectory is obtained by solving an optimal control problem with constraints. Local minima are avoided by choosing intermediate objectives based on the real-time environment.
Trajectory tracking of wheeled mobile robot by adopting iterative learning control with predictive, current, and past learning items
Authors: Yu Chong , Chen Xiong
Published: April 2014

In this paper, an iterative learning control algorithm is adopted to solve the high-precision trajectory tracking issue of a wheeled mobile robot with time-varying, nonlinear, and strong-coupling dynamics properties. The designed iterative learning control law adopts predictive, current and past learning items to drive the state variables, and input variables, and outputs variables converge to the bounded scope of their desired values. The algorithm can enhance the control performance, stability and robust characteristics. The rigorous mathematical proof of the convergence character of the proposed iterative learning control algorithm is given. The feasibility, effectiveness, and robustness of the proposed algorithm are illustrated by quantitative experiments and comparative analysis. The experimental results show that the proposed iterative learning control algorithm has an outstanding control effect on the trajectory tracking issue of wheeled mobile robots.
Teacher and student perspectives on one-to-one pedagogy: practices and possibilities
Authors: Carey Gemma , Grant Catherine
Published: April 2014

This paper explores teachers’ and students’ perceptions of one-to-one pedagogy, in the context of tertiary vocal and instrumental tuition. Teachers and students at one Australian conservatoire participated in interviews and focus groups that explored their experiences and perceptions on the nature, value, effectiveness and challenges of one-to-one learning and teaching. Four key themes emerged: customising teaching to the learner, the teacher–student relationship, negotiating issues of student dependency versus self-sufficiency, and situating one-to-one in a broader institutional context. Aside from an undisputed view that one-to-one is essential to students’ learning and development, findings indicate diverse perceptions, including discrepancies between intentions of teachers and their pedagogical practice, and between teacher practice and student expectations. By drawing on voices ‘from the inside’ to characterise one-to-one practice, the study contributes to evidence-based research about learning and teaching in the conservatoire environment.
THE PETROGLYPHIC PRAYERS ON THE SUN STONE OF MOTECUHZOMA ILHUICAMINA
Authors: Boone Elizabeth Hill , Collins Rochelle
Published: April 2014

The Sun Stone of Motecuhzoma Ilhuicamina is one of the major monuments revealed by excavations in and around the Aztec Templo Mayor since 1978. Featuring the sun disk on its top surface and the Mexica conquest of 11 enemy polities on its cylindrical sides, it is considered a gladiatorial stone, similar in both iconography and function to the later Stone of Tizoc. While Tizoc's stone locates its conquest scenes between earth and sky bands, this sun stone uniquely places its conquests between two bands of repeating motifs. The authors argue that these bands are extraordinary examples of pictographic texts that parallel and likely called forth ritual speech acts. The iconography and patterning of the motifs reveal the bands to be visual exhortations or prayers related to human sacrifice specifically associated with Tezcatlipoca. The complex pattern of the repeating motifs is rhythmic and reflects the discourse structure of Nahuatl high speech.
RÍO BEC GRAFFITI: A PRIVATE FORM OF ART
Authors: Patrois Julie
Published: April 2014

This article focuses on graffiti recorded in the micro-region of Río Bec (a 10 × 10 km zone around Group B), an art form well-known but little studied to date. Incised in plastered supports (wall, benches, or doorjambs), graffiti is found on residences of all ranks. A meticulous recording method has enabled us to distinguish two classes: graffiti produced during a building's occupation and those executed post-abandonment. The former were probably made by the residence dwellers themselves, children and adults. Their productions, which can be considered authentic artistic creations, reflected their unequal technical capacities, talents, ages, and inspirations. The subject matter was personal; remarkable individuals or animals, or outstanding collective events as memorialized by individuals. These graffiti emerge as the principal form of individual expression (retrieved by the archaeologist) from Río Bec society. Once the buildings were abandoned and full of rubble, new graffitists (occasional visitors or squatters) decorated the still accessible portions of plastered walls and notably illustrated some specific topics, such as female imagery and fabulous entities perhaps drawn during specific ceremonies. In the region as a whole, where glyphic inscriptions are scarce, graffiti provide a privilegedemicsource for the understanding of Río Bec society.
LIVING TOGETHER IN RÍO BEC HOUSES: CORESIDENCE, RANK, AND ALLIANCE
Authors: Arnauld M. Charlotte , Michelet Dominique , Nondédéo Philippe
Published: April 2014

In an attempt to interpret Classic Maya elite and commoner residential patterns beyond usual assumptions about filiation, family cycle, and household economic adaptation, we explore the specific ways people were “living together,” in the sense of the coresidence concept, in Maya societies conceived of as ranked societies, or “house societies,” as created by Claude Lévi-Strauss. Beyond kinship and economic organization, residential patterns can be understood as part of long-term strategies designed by inhabitants to integrate their social unit into the politico-religious city. The residential system of the Río Bec zone, where a major research project was carried out from 2002 to 2010, offers a series of well-defined architectural solutions, some of them common to most central lowlands cities, while others are innovative as forerunners of the northern lowlands large multiroom palaces. This paper analyzes Late and Terminal Classic period Río Bec domestic architecture in order to outline the material correlates of coresidence, growth, ranking, and alliance within and between Classic Maya social groupings.
A quantum random number generator certified by value indefiniteness
Authors: ABBOTT ALASTAIR A. , CALUDE CRISTIAN S. , SVOZIL KARL
Published: April 2014

In this paper we propose a quantum random number generator (QRNG) that uses an entangled photon pair in a Bell singlet state and is certified explicitly by value indefiniteness. While ‘true randomness’ is a mathematical impossibility, the certification by value indefiniteness ensures that the quantum random bits are incomputable in the strongest sense. This is the first QRNG setup in which a physical principle (Kochen–Specker value indefiniteness) guarantees that no single quantum bit that is produced can be classically computed (reproduced and validated), which is the mathematical form of bitwise physical unpredictability.

We discuss the effects of various experimental imperfections in detail: in particular, those related to detector efficiencies, context alignment and temporal correlations between bits. The analysis is very relevant for the construction of any QRNG based on beam-splitters. By measuring the two entangled photons in maximally misaligned contexts and using the fact that two bitstrings, rather than just one, are obtained, more efficient and robust unbiasing techniques can be applied. We propose a robust and efficient procedure based onXORing the bitstrings together – essentially using one as a one-time-pad for the other – to extract random bits in the presence of experimental imperfections, as well as a more efficient modification of the von Neumann procedure for the same task. We also discuss some open problems.
Randomness in biology
Authors: HEAMS THOMAS
Published: April 2014

Biology has contradictory relationships with randomness. First, it is a complex issue for an empirical science to ensure that apparently random events are truly random, this being further complicated by the loose definitions of unpredictability used in the discipline. Second, biology is made up of many different fields, which have different traditions and procedures for considering random events. Randomness is in many ways an inherent feature of evolutionary biology and genetics. Indeed, chance/Darwinian selection principles, as well as the combinatorial genetic lottery leading to gametes and fertilisation, rely, at least partially, on probabilistic laws that refer to random events. On the other hand, molecular biology has long been based on deterministic premises that have led to a focus on the precision of molecular interactions to explain phenotypes, and, consequently, to the relegation of randomness to the marginal status of ‘noise’. However, recent experimental results, as well as new theoretical frameworks, have challenged this view and may provide unifying explanations by acknowledging the intrinsic stochastic dimension of intracellular pathways as a biological parameter, rather than just as background noise. This should lead to a significant reappraisal of the status of randomness in the life sciences, and have important consequences on research strategies for theoretical and applied biology.
Toward a probabilistic biology
Authors: KUPIEC JEAN-JACQUES
Published: April 2014

Stochastic gene expression (SGE) is now considered to be an established fact and has become an important subject of research (Viñuelas et al. 2012). During the last decade, the availability of new techniques has made possible the production of more precise and more spectacular data showing the extensive variability in gene expression occurring between individual cells. However, evidence supporting probabilistic models of cell behaviour and gene expression has been available for quite a long time – for example, see the reviews in Laforge et al. (2005) and Golubev (2010). It should be noted that the first model of stochastic cell differentiation was proposed in 1964 (Till et al. 1964), which is almost at the same time as the genetic programming theory (Jacob and Monod 1961), which is deterministic in nature. One can thus wonder why the determinist view of biology has remained dominant for such a long time, and what makes a probabilistic view more acceptable nowadays? In this short paper, I will briefly argue that there is a strong epistemological obstacle to the acceptance of probabilism in biology, and that even today SGE is not integrated into a fully probabilistic approach of cellular processes, but rather into a concept that I call ‘determinism with noise’. I will argue that a new fully probabilistic theoretical framework is needed to truly integrate the stochastic aspects of cell physiology.
Irrigation as an adaptive strategy to climate change: an economic perspective on Brazilian agriculture
Authors: da Cunha Dênis Antônio , Coelho Alexandre Bragança , Féres José Gustavo
Published: April 2014

This paper analyzes the potential effects of climate change on Brazilian agriculture by considering irrigation as an adaptive strategy. Investigations were performed to determine how climatic variability influences irrigation and whether this adaptive measure actually reduces producers' vulnerability to climate change. We used a simultaneous equations model with endogenous switching to account for the heterogeneity in the decision of whether to use adaptive measures. We compared the expected land values under the actual and counterfactual cases of farm households that either adapt or do not adapt to climate change. Simulation results show that irrigation can be an effective tool for counteracting the harmful effects of climate change. The income of farmers tends to increase on lands where irrigation technologies are practiced. These conclusions confirm the need to invest in adaptation strategies to prepare Brazil for coping with the adverse effects of global climate change.