bluuebunny/crossref_metadata_2025 huggingface dataset:
Proposta para a estimativa da acurácia de redes geodésicas horizontais integrando análise de robustez e de covariância
Authors: Klein Ivandro , Matsuoka Marcelo Tomio , Monico João Francisco Galera
Published: October 2014

O objetivo deste trabalho é apresentar uma proposta para o controle de qualidade de redes geodésicas bidimensionais por meio das análises de robustez e de covariância. Na metodologia proposta, a acurácia (exatidão) posicional de cada ponto é estimada por meio de uma possível tendência posicional (via análise de robustez), além da própria precisão (incerteza) posicional (via análise de covariância), sendo ainda uma medida independente do datum adotado. Além da apresentação do desenvolvimento teórico do método, a aplicação do mesmo é demonstrada em um exemplo numérico. Os resultados obtidos indicam que, em geral, quanto maior o afastamento de um vértice desconhecido do(s) ponto(s) de controle da rede, maior é a propagação de erros aleatórios sobre este, e, quanto menos observações redundantes ao redor de um ponto, maior é a influência de possíveis erros (não aleatórios) sobre este, quando não detectados.
A influência da calibração aérea de uma câmara digital de baixo custo integrada com um sistema LIDAR no processamento de aerotriangulação
Authors: Debiasi Paula , Mitishita Edson A.
Published: October 2014

Esta pesquisa teve como objetivo investigar a influência da calibração aérea de uma câmara digital de baixo custo, integrada fisicamente com um sistema LIDAR, na correção dos erros sistemáticos de observações fotogramétricas para o processo de aerotriangulação. A calibração aérea foi realizada com fotografias tomadas de um campo de prova empregando-se duas configurações de bloco fotogramétrico: sem faixas cruzadas e faixas cruzadas. As coordenadas das estações de exposição, provenientes da integração da câmara com os sensores de orientação e posição do sistema LIDAR, foram utilizadas como injunção nos processamentos de calibração aérea. A verificação do desempenho dos parâmetros de orientação interior (POI), determinados nas calibrações aéreas, foi realizada através de processamentos de aerotriangulação de um bloco fotogramétrico (utilizando as coordenadas das estações de exposição), obtido em local e época diferente do que foi empregado nos procedimentos de calibração aérea. Parâmetros de orientação interior determinados pelo Método das Câmaras Convergentes, utilizando um campo de prova terrestre, também foram utilizados para a correção de erros sistemáticos das observações fotogramétricas deste bloco de fotografias simplesmente para fins de comparações. Os resultados demonstraram que as exatidões obtidas nos processamentos de aerotriangulação empregando os POI provenientes das calibrações aéreas foram consideravelmente superiores às exatidões obtidas no processamento empregando os POI determinados na calibração terrestre, principalmente no que se refere à exatidão altimétrica. Conclui-se que a exatidão altimétrica dos processamentos utilizando injunção nas coordenadas do centro perspectivo da câmara apresenta-se mais dependente da qualidade dos POI empregados do que a exatidão planimétrica.
Application of median-equation approach for outlier detection in geodetic networks
Authors: Hekimoglu Serif , Erdogan Bahattin
Published: October 2014

In geodetic measurements some outliers may occur sometimes in data sets, depending on different reasons. There are two main approaches to detect outliers as Tests for outliers (Baarda's and Pope's Tests) and robust methods (Danish method, Huber method etc.). These methods use the Least Squares Estimation (LSE). The outliers affect the LSE results, especially it smears the effects of the outliers on the good observations and sometimes wrong results may be obtained. To avoid these effects, a method that does not use LSE should be preferred. The median is a high breakdown point estimator and if it is applied for the outlier detection, reliable results can be obtained. In this study, a robust method which uses median with or as a treshould value on median residuals that are obtained from median equations is proposed. If the a priori variance of the observations is known, the reliability of the new approch is greater than the one in the case where the a priori variance is unknown.
Use of control charts for multi-temporal analysis of geodetic auscultation data from dams
Authors: Quintanilha José Alberto , Ho Linda Lee , Machado Cláudia Aparecida Soares , Blitzkow Denizar
Published: October 2014

Geodesic auscultation can be used to monitor the movement of dam structures by measuring the distance, at different epochs from fixed positions (pillars) to other positions (targets). It is important to identify the targets that present atypical measurements to permit managers to take corrective actions. After fitting a model using the Least Squares Method (LSM), the residuals normally display random behavior. Multivariate control charts are then applied to the residuals of the fitted model from data taken of geodesic survey campaigns conducted at different epochs. Control charts have been widely applied in other fields of research than production processes such as public health, marketing, services. The results show that it is possible for monitoring the multi-temporal stability by the multivariate control charts. The method provides complementary information than the classical univariate statistical analysis.
Produtividade de cana-de-açúcar sob adubação com torta de filtro enriquecida com fosfato solúvel
Authors: Santos Diego Henriques , Tiritan Carlos Sérgio , Foloni José Salvador Simoneti , Fabris Luciana Boulhosa
Published: October 2014

O fósforo é considerado elemento essencial para as plantas e encontrado em baixa quantidade nos solos brasileiros. A torta de filtro, resíduo composto da mistura de bagaço moído e lodo da decantação, apresenta altos teores de matéria orgânica, fósforo e cálcio. O fósforo existente na torta de filtro é orgânico, sendo que a liberação do mesmo e do nitrogênio se dão gradativamente, por mineralização e por ataque de microorganismos no solo. O trabalho teve por objetivo avaliar o crescimento vegetativo e a produtividade da cana-de-açúcar, em função da adubação com torta de filtro enriquecida com fosfato solúvel. O experimento foi conduzido a campo, em Presidente Prudente (SP). Adotou-se o delineamento experimental em blocos completos ao acaso, no esquema fatorial 5x4, onde o primeiro fator constou de níveis de torta de filtro (0 t ha-1; 0,5 t ha-1; 1,0 t ha-1; 2,0 t ha-1; e 4,0 t ha-1) e o segundo de níveis de fósforo (0 kg ha-1, 50 kg ha-1, 100 kg ha-1 e 200 kg ha-1 de P2O5), com 4 repetições, totalizando 80 parcelas. Os parâmetros avaliados foram o número de perfilhos, aos 30, 60, 90 e 120 dias após o plantio, ºBrix e produtividade. A produtividade de colmos e o perfilhamento foram influenciados pelas doses de torta de filtro aplicadas ao solo. As doses de torta de filtro e suas combinações com o fosfato não alteraram a qualidade do caldo (Brix), por ocasião da colheita.
Cultivares de milho e de gramíneas forrageiras sob monocultivo e consorciação
Authors: Jakelaitis Adriano , Daniel Thales Augusto Duarte , Alexandrino Emerson , Simões Lindomar Pereira , Souza Kennedy Vidal , Ludtke Josia
Published: October 2014

A pesquisa teve como objetivo avaliar o desempenho de cultivares de milho e de espécies forrageiras (Brachiaria brizantha e Panicum maximum), em cultivos solteiro e consorciado. O delineamento experimental foi de blocos completos casualizados, em esquema fatorial 3x4 + 7, com quatro repetições. O primeiro fator foi constituído por três cultivares de milho (variedade AL Bandeirantes, híbrido duplo AG 2040 e híbrido triplo Pioneer 30F87) e o segundo por quatro cultivares forrageiras (Marandu e Xaraés, de B. brizantha, e Tanzânia e Mombaça, de P. maximum). Os sete tratamentos adicionais corresponderam aos respectivos monocultivos das cultivares testadas. A semeadura do milho foi realizada no espaçamento de 1,0 m entre fileiras e as forrageiras foram semeadas a lanço, em semeadura simultânea ao milho. Observou-se que o híbrido Pioneer 30F87 foi o mais produtivo, tanto em consórcio quanto sob monocultivo. O milho interferiu nos ganhos de massa seca das forrageiras, quando comparadas aos cultivos solteiros. Entre as forrageiras estabelecidas sob consórcio, as cultivares de P. maximum foram as mais produtivas, enquanto a cultivar Mombaça destacou-se com a maior massa seca produzida em monocultivo.
Produção de silagem de híbridos de milho e sorgo sem nitrogênio de cobertura em safra de verão
Authors: Guareschi Roni Fernandes , Brasil Rafaella Belchior , Perin Adriano , Ribeiro Jessika Mara Martins
Published: October 2014

A obtenção de híbridos que apresentem elevada participação de grãos na massa seca total, colmos e folhas mais digestíveis e alta produtividade total de massa seca é o principal objetivo dos programas de melhoramento visando à ensilagem. Diante disto, o objetivo deste trabalho foi avaliar a produção de silagem de planta inteira de híbridos de milho e sorgo, na safra de verão, sem adubação nitrogenada de cobertura. A pesquisa foi conduzida em Latossolo Vermelho distroférrico de textura média, no município de Rio Verde, sudoeste de Goiás. Adotouse o delineamento de blocos ao acaso, com seis tratamentos e quatro repetições. Os tratamentos foram milho (P-30F90, DKB-177 e AG-7010) e sorgo (experimental 1, experimental 2 e Volumax). O milho foi semeado em espaçamento de 0,90 m, com 6 plantas por metro, e o sorgo em espaçamento de 0,45 m, com 8 plantas por metro. As avaliações constaram da produção de biomassa da parte aérea, bem como da proporção de massa fresca e seca de colmo, folhas e espigas de milho e panículas de sorgo, aos 105 dias após a emergência (DAE). O híbrido de sorgo Volumax apresentou a maior produtividade de biomassa, para fins de ensilagem. Os híbridos de milho conferiram maior proporção de espigas, na relação espigas/biomassa total, quando comparados à relação panículas/biomassa total dos híbridos de sorgo, demonstrando a importância da utilização de milho para agregar qualidade à silagem.
Review of the Old World Leafhopper Genus Futasujinus Ishihara (Hemiptera: Cicadellidae: Deltocephalinae: Paralimnini), with Description of Three New Species
Authors: Zhang Huining , Dai Wu , Zhang Yalin
Published: October 2014

The Old World leafhopper genus Futasujinus Ishihara is revised and redescribed. Eight species, including three new species, are recognized in the genus: F. amuriensis (Metcalf) (China, Japan, Korea, Mongolia, and Russia), F. biarmatus Dlabola (Mongolia), F. candidus (Matsumura) (China, Russia, Korea, and Japan), F. dietrichi sp. nov. (China), F. hastatus sp. nov. (China), F. koreacolaKwon & Lee, 1979 (Korea), F. towadensis (Matsumura) (Japan), and F. truncates sp. nov. (China). All species from China are described. A key to the species in this genus is given, and their genital structures are illustrated.
Comparative Study of the Antennae of Dendroctonus rhizophagus and Dendroctonus valens (Curculionidae: Scolytinae): Sensilla Types, Distribution and Club Shape
Authors: López María Fernanda , Armendáriz-Toledano Francisco , Sámano Jorge E Macías , Shibayama-Salas Mineko , Zúñiga Gerardo
Published: October 2014

We compared the antennae of two sibling bark beetle species, Dendroctonus rhizophagus Thomas and Bright and Dendroctonus valens LeConte, to identify biologically and taxonomically relevant differences. Specifically, we characterized the diversity of sensilla types by using environmental scanning electron microscopy, quantified the abundance and distribution of the different types of sensilla on the antennal club, and characterized club shape through multivariate and geometric morphometric analyses. We identified four classes of sensilla in both species: chaetica, fluted, trichodea (three distinct types), and basiconica (long and short). ANOVA and MANOVA demonstrated that the number and distribution of sensilla with the potential for chemoreception (i.e., short and long basiconica) differed between species and sexes. Notably, the long sensilla basiconica in the third sensory band were clustered in D. rhizophagus but not in D.valens. Geometric morphometric analysis using 27 landmarks showed that antennal club shape differed significantly between the two species and was not correlated with antennal size. The shape differences were associated with the number and distribution of sensilla.
Anti‐Inflammatory Protein Tumor Necrosis Factor‐α–Stimulated Protein 6 (TSG‐6) Promotes Early Gingival Wound Healing: An In Vivo Study
Authors: Beltran Stacy R. , Svoboda Kathy K.H. , Kerns David G. , Sheth Akash , Prockop Darwin J.
Published: October 2014

Background: Human multipotent mesenchymal stromal cells (hMSCs) produce tumor necrosis factor (TNF)‐α–stimulated protein 6 (TSG‐6). TSG‐6 modulates proinflammatory cytokine cascades and enhances tissue repair. This study tests the effects of recombinant human TSG‐6 (rhTSG‐6) on gingival wound healing within the first 2 days post‐surgery.

Methods: After gingival resection in 120 Sprague‐Dawley rats, 2 µg rhTSG‐6 in 5‐µL phosphate‐buffered saline (PBS) or the same volume of only PBS solution was injected into gingival tissue approximating the surgical wound. Control animals did not receive injections. Tissue biopsies and blood were collected at 1 to 2, 6 to 8, 24, and 48 hours post‐surgery (n = 10 per group). Specimens were analyzed via histologic analysis and enzyme‐linked immunosorbent assay (ELISA) for quantification and comparison of inflammatory markers interleukin (IL)‐1β, IL‐6, TNF‐α, and myeloperoxidase (MPO). Wound photographs were taken for a double‐masked clinical assessment at each time period. Weights were recorded for all animals pre‐ and post‐surgery.

Results: Animals injected with rhTSG‐6 had significantly less severe clinical inflammation at 6 to 8 (P = 0.01228), 24 (P = 0.01675), and 48 (P = 0.0186) hours. Sham and control animals had more weight loss at 24 and 48 hours. Sham and control animals had more pronounced cellular infiltrate. rhTSG‐6‐treated animals had significantly less MPO (P = 0.027) at 24 hours and IL‐1β (P = 0.027) at 24 and 48 hours. IL‐6 showed a marginal significant difference at 6 to 8 hours, but there was no significant difference for TNF‐α.

Conclusion: rhTSG‐6 reduced postoperative gingival inflammation by reducing levels of proinflammatory cytokines and cellular infiltrate and may offer significant promise as an anti‐inflammatory agent for gingival surgery.
Modulation of Facial Processing by Identity Information in a Face Similarity Evaluation Task
Authors: Zhou Qiang , Ye Xindong , Liao Danyang , Zhang Weidong
Published: October 2014

We used a face similarity task with event-related potentials (ERPs) in a study conducted with 22 individuals in order to examine the processing of identity information. During the evaluation task, significant variations in the late negative potential were elicited by different identity
contexts of couples versus strangers. By contrast, the face-specific N170 component was not significantly affected by variations in identity context. In addition, participants' behavioral data were significantly influenced by the task instructions, but not by the true relationship of the couple.
Together, ERP and behavioral results suggest that the evaluation of face similarity with identity information occurs at a later stage.
Early Maladaptive Schemas as Predictors of Interpersonal Orientation and Peer Connectedness in University Students
Authors: Yoo Gyesook , Park Ju Hee , Jun Hey Jung
Published: October 2014

In this study we examined whether or not early maladaptive schemas regarding disconnection and rejection influenced peer connectedness of university students in emerging adulthood. We also investigated the mediating role of interpersonal orientation on these relationships. The participants
were 304 students at universities in Korea, aged between 18 and 25 years. Results of structural equation modeling demonstrated that the defectiveness/shame schema had an indirect, negative effect on peer connectedness via interpersonal orientation, and the abandonment/instability schema had
an indirect, positive influence on peer connectedness. The social isolation/alienation schema negatively and directly affected peer connectedness. Our findings suggest that when a sense of disconnection and rejection develops during childhood and adolescence, individuals show a relatively
stable tendency to either avoid or overvalue interpersonal relationships. This may lead to difficulties in establishing peer relationships in emerging adulthood.
Digital Game-Based Learning: A Supplement for Medication Calculation Drills in Nurse Education
Authors: Foss Brynjar , Løkken Atle , Leland Arne , Stordalen Jørn , Mordt Petter , Oftedal Bjørg F.
Published: October 2014

Student nurses, globally, appear to struggle with medication calculations. In order to improve these skills among student nurses, the authors developed The Medication Game – an online computer game that aims to provide simple mathematical and medical calculation drills, and help students practise standard medical units and expressions. The aim of this study was to examine whether baccalaureate student nurses who played The Medication Game as a supplement to lectures and task-solving during a medication calculation course improved their examination results compared to a control group who used lectures and task-solving only. The authors used a randomised controlled design to study 201 students enrolled in medication calculation courses. The main measures were examination results, gaming high scores, the number of gaming self-tests and gaming time. There was no significant difference between groups in examination pass rates: 56% of the control group and 67% of the gamers passed. However, gamers who passed the examination had higher gaming high scores ( p < .01) and used the gaming self-tests more frequently ( p < .01) than gamers who failed the examination. The authors concluded that The Medication Game did not significantly improve examination results, but that using the game frequently appeared to influence the examination outcome positively.
The Use of Weblogs in Citizenship Education: A Theoretical Analysis of the Integration of Weblogs and the English Citizenship Curriculum
Authors: Hung Cheng-Yu
Published: October 2014

New technologies have changed the way people perceive the world as well as access to knowledge. The ubiquitous influence of the Internet has also impacted traditional teaching in schools. According to existing studies, the weblog, or blog, is one of the most commonly applied new technologies in teaching due to its ability to allow a combination of text, photographs, videos and discussion forums on an interactive platform. Its influence is particularly keenly felt in language teaching, distance learning and natural science education. However, its use in the humanities, including history, geography and citizenship education, is relatively unexplored. The author discerns a strong connection between weblogs and citizenship education, and argues that they share the mutual objectives of transmitting knowledge, enhancing deliberative interaction, and cultivating participation and contribution, as well as generating a sense of community. While citizenship education is widely included in school timetables across countries to stave off social apathy and reverse the trend of ever declining participation in public affairs, the nature of blogging can be an effective tool to encourage information-sharing and opinion exchange between pupils as well as teachers, which may further stimulate participation and confidence in schools, the community and the larger society, and transform the acquired civic knowledge in class into real-life experience. This article investigates this issue by means of theoretical analysis and, in order to facilitate understanding, the author uses the English citizenship curriculum as an example to contextualise the theoretical arguments and demonstrate the integrative potential of the subject and this technological device. Not only are the advantages proposed in the research, but also possible disadvantages are illustrated, in order to bring additional attention to the detrimental effects that the new technology may have.
Insights into Contextualised Learning: How Do Professional Examiners Construct Shared Understanding through Feedback?
Authors: Johnson Martin
Published: October 2014

This project uses the community of practice metaphor to explore some of the discursive characteristics of learning that take place when a group of United Kingdom-based professional examiners engage in joint-work activity in both face-to-face and remote computer-mediated communication contexts. Professional examiners are all subject experts, and the essence of their work, reinforced by the hierarchical structures that organise their working relationships, means that examiner ‘learning’ involves the convergence of understandings of less senior examiners with those of other, more senior examiners around key concepts. This project looks at how more senior examiners help to induct other examiners into ways of thinking within a professional community. It also looks at the role of boundary objects, such as mark schemes, which help to coordinate different perspectives within the community. Focusing specifically on the feedback that senior examiners give to less senior examiners in their team, this study extends the use of a discourse analytical approach that has only previously been used in face-to-face learning interaction to look at how shared meanings can be built through social interaction in an applied work situation.
Goodwill Impairment Charges and Analyst Forecast Properties
Authors: Chen Lucy Huajing , Krishnan Jayanthi , Sami Heibatollah
Published: October 2014

SYNOPSIS

We examine the association between goodwill impairment charges and analysts' forecast accuracy and dispersion. We compare a test sample of firm-quarters with reported goodwill impairment charges during 2003–2007, and two control samples (matched on propensity scores and performance) of firm-quarters that do not report impairment charges. We find that analysts' forecasts are less accurate and more dispersed for the impairment sample than for the control samples. The magnitude of impairment charges is also negatively associated with forecast accuracy and positively associated with forecast dispersion. However, two forms of monitoring, auditor industry specialization and institutional ownership, reduce the adverse effect of goodwill impairments on analyst forecast dispersion.

JEL Classifications: G14; M41; M44
The Effect of China's Weak Institutional Environment on the Quality of Big 4 Audits
Authors: Ke Bin , Lennox Clive S. , Xin Qingquan
Published: October 2014

This study examines whether China's weak institutional environment results in lower-quality audits by the Big 4 firms. We find that the Big 4 assign their less experienced partners to companies that are listed only in China compared with clients cross-listed in Hong Kong. The Big 4 are less likely to issue modified audit reports, and they charge lower audit fees for clients that are listed only in China. Finally, companies listed only in China have larger signed abnormal accruals than do companies cross-listed in Hong Kong. Overall, we conclude that the weak institutional environment in China results in the Big 4 firms providing lower-quality audits to companies that are listed only in China.
Empagliflozin Reduces Blood Pressure in Patients With Type 2 Diabetes and Hypertension
Authors: Tikkanen Ilkka , Narko Kirsi , Zeller Cordula , Green Alexandra , Salsali Afshin , Broedl Uli C. , Woerle Hans J.
Published: October 2014

OBJECTIVE

To investigate the efficacy, safety, and tolerability of empagliflozin in patients with type 2 diabetes and hypertension.

RESEARCH DESIGN AND METHODS

Patients (N = 825) with type 2 diabetes and hypertension (mean seated systolic blood pressure [SBP] 130–159 mmHg and diastolic blood pressure [DBP] 80–99 mmHg) were randomized (double blind) to 10 mg or 25 mg empagliflozin or placebo once daily for 12 weeks.

RESULTS

At week 12, adjusted mean difference versus placebo in change from baseline in mean 24-h SBP (ambulatory blood pressure monitoring [ABPM]) was −3.44 mmHg (95% CI −4.78, −2.09) with 10 mg empagliflozin and −4.16 mmHg (−5.50, −2.83) with 25 mg empagliflozin (both P < 0.001). At week 12, adjusted mean difference versus placebo in change from baseline in mean 24-h DBP (ABPM) was −1.36 mmHg (95% CI −2.15, −0.56) with 10 mg empagliflozin and −1.72 mmHg (95% CI −2.51, −0.93) with 25 mg empagliflozin (both P < 0.001). Changes in office BP were consistent with ABPM. Adjusted mean difference versus placebo in change from baseline in HbA1c at week 12 was −0.62% (95% CI −0.72, −0.52) (−6.8 mmol/mol [95% CI −7.9, −5.7]) with 10 mg empagliflozin and −0.65% (95% CI −0.75, −0.55) (−7.1 mmol/mol [95% CI −8.2, −6.0]) with 25 mg empagliflozin (both P < 0.001). Empagliflozin was well tolerated. One patient on placebo and one patient on 10 mg empagliflozin reported events consistent with volume depletion.

CONCLUSIONS

Empagliflozin was associated with significant and clinically meaningful reductions in BP and HbA1c versus placebo and was well tolerated in patients with type 2 diabetes and hypertension.
Non-uniform Continuum Model for Solvated Species Based on Frozen-Density Embedding Theory: The Study Case of Solvatochromism of Coumarin 153
Authors: Shedge Sapana V. , Zhou Xiuwen , Wesolowski Tomasz A.
Published: October 2014

Recent application of the Frozen-Density Embedding Theory based continuum model of the solvent, which is used for calculating solvatochromic shifts in the UV/Vis range, are reviewed. In this model, the solvent is represented as a non-uniform continuum taking into account both the statistical
nature of the solvent and specific solute–solvent interactions. It offers, therefore, a computationally attractive alternative to methods in which the solvent is described at atomistic level. The evaluation of the solvatochromic shift involves only two calculations of excitation energy
instead of at least hundreds needed to account for inhomogeneous broadening. The present review provides a detailed graphical analysis of the key quantities of this model: the average charge density of the solvent (
Mechanisms of Ligand–Protein Interaction in Sec-14-like Transporters Investigated by Computer Simulations
Authors: Helbling Rachel E. , Lamprakis Christos , Aeschimann Walter , Bolze Cristin S. , Stocker Achim , Cascella Michele
Published: October 2014

We review our recent work on protein–ligand interactions in vitamin transporters of the Sec-14-like protein. Our studies focused on the cellular-retinaldehyde binding protein (CRALBP) and the ?-tocopherol transfer protein (?-TTP). CRALBP is responsible for mobilisation
and photo-protection of short-chain cis-retinoids in the dim-light visual cycle or rod photoreceptors. ?-TTP is a key protein responsible for selection and retention of RRR-?-tocopherol, the most active isoform of vitamin E in superior animals. Our simulation studies evidence
how subtle chemical variations in the substrate can lead to significant distortion in the structure of the complex, and how these changes can either lead to new protein function, or be used to model engineered protein variants with tailored properties. Finally, we show how integration of computational
and experimental results can contribute in synergy to the understanding of fundamental processes at the biomolecular scale.
“Why and How it Works”: The Development of Hypervalent Iodine Reagents as an Illustration for the Collaboration of Chemical Synthesis with Modeling and Simulation
Authors: Lüthi Hans Peter , Togni Antonio
Published: October 2014

Much of the focus of quantum chemical modeling and simulation is on understanding chemical phenomena and in assisting experiment to further improve and develop the respective chemistry. Given the computational tools available today, rather than assisting the development of new
chemicals, modeling and simulation are in the process of making the step towards guiding experiment towards novel targets. In this article we show how an intense collaboration between chemical synthesis and computation leads to a better understanding of hypervalent iodine reagents and
how modeling and simulation may direct the search of novel reagents.
Predicting the Genes Regulated by MicroRNAs via Binding Sites in the 3' Untranslated and Coding Regions
Authors: Vaníček Jiří
Published: October 2014

MicroRNAs form one of the groups of small noncoding RNA molecules that have completely changed our understanding of gene regulatory networks. Because microRNAs have been discovered only relatively recently, most of their functions remain unknown, providing a challenge to both experiment
and theory. I review several computational approaches pursued in our group to answer this challenge. In particular, I show that a few rather simple ideas can go a long way in predicting accurately genes regulated by microRNAs via binding sites both in the coding and 3' untranslated regions
(3'UTRs). Finally, I mention briefly several applications, including two collaborations with experimental groups, which have shed new light on the latency and reactivation of herpesviruses, and on the maturation of red blood cells.
Immediate complications associated with high-flow cerebrospinal fluid egress during endoscopic endonasal skull base surgery
Authors: Kerr Edward E. , Prevedello Daniel M. , Jamshidi Ali , Ditzel Filho Leo F. , Otto Bradley A. , Carrau Ricardo L.
Published: October 2014

Endoscopic expanded endonasal approaches (EEAs) to the skull base are increasingly being used to address a variety of skull base pathologies. Postoperative CSF leakage from the large skull base defects has been well described as one of the most common complications of EEAs. There are reports of associated formation of delayed subdural hematoma and tension pneumocephalus from approximately 1 week to 3 months postoperatively. However, there have been no reports of immediate complications of high-volume CSF leakage from EEA skull base surgery. The authors describe two cases of EEAs in which complications related to rapid, large-volume CSF egress through the skull base surgical defect were detected in the immediate postoperative period. Preventive measures to reduce the likelihood of these immediate complications are presented.
Transnasal odontoid resection: is there an anatomic explanation for differing swallowing outcomes?
Authors: Van Abel Kathryn M. , Mallory Grant W. , Kasperbauer Jan L. , M.D.  , Moore Eric J. , Price Daniel L. , O’Brien Erin K. , Olsen Kerry D. , Krauss William E. , Clarke Michelle J. , Jentoft Mark E. , Van Gompel Jamie J.
Published: October 2014

Object

Swallowing dysfunction is common following transoral (TO) odontoidectomy. Preliminary experience with newer endoscopic transnasal (TN) approaches suggests that dysphagia may be reduced with this alternative. However, the reasons for this are unclear. The authors hypothesized that the TN approach results in less disruption of the pharyngeal plexus and anatomical structures associated with swallowing. The authors investigate the histological and gross surgical anatomical relationship between pharyngeal plexus innervation of the upper aerodigestive tract and the surgical approaches used (TN and TO). They also review the TN literature to evaluate swallowing outcomes following this approach.

Methods

Seven cadaveric specimens were used for histological (n = 3) and gross anatomical (n = 4) examination of the pharyngeal plexus with the TO and TN surgical approaches. Particular attention was given to identifying the location of cranial nerves (CNs) IX and X and the sympathetic chain and their contributions to the pharyngeal plexus. S100 staining was performed to assess for the presence of neural tissue in proximity to the midline, and fiber density counts were performed within 1 cm of midline. The relationship between the pharyngeal plexus, clivus, and upper cervical spine (C1-3) was defined.

Results

Histological analysis revealed the presence of pharyngeal plexus fibers in the midline and a significant reduction in paramedian fiber density from C-2 to the lower clivus (p < 0.001). None of these paramedian fibers, however, could be visualized with gross inspection or layer-by-layer dissection. Laterally based primary pharyngeal plexus nerves were identified by tracing their origins from CNs IX and X and the sympathetic chain at the skull base and following them to the pharyngeal musculature. In addition, the authors found 15 studies presenting 52 patients undergoing TN odontoidectomy. Of these patients, only 48 had been swallowing preoperatively. When looking only at this population, 83% (40 of 48) were swallowing by Day 3 and 92% (44 of 48) were swallowing by Day 7.

Conclusions

Despite the midline approach, both TO and TN approaches may injure a portion of the pharyngeal plexus. By limiting the TN incision to above the palatal plane, the surgeon avoids the high-density neural plexus found in the oropharyngeal wall and limits injury to oropharyngeal musculature involved in swallowing. This may explain the decreased incidence of postoperative dysphagia seen in TN approaches. However, further clinical investigation is warranted.
Endoscopic skull base reconstruction: a review and clinical case series of 152 vascularized flaps used for surgical skull base defects in the setting of intraoperative cerebrospinal fluid leak
Authors: Thorp Brian D. , Sreenath Satyan B. , Ebert Charles S. , M.P.H.  , Zanation Adam M.
Published: October 2014

Endoscopic skull base surgery continues to rapidly evolve, requiring comparable advances in reconstructive techniques. While smaller skull base defects with low intraoperative CSF flow have been successfully managed with a variety of avascular and/or noncellular techniques, larger defects with high CSF flow require more robust repairs often in the form of vascularized flaps, which confer excellent success rates in this setting. Despite these successful outcomes, a paucity of data describing specific patient and operative characteristics and their effects on repair exist. Therefore, a retrospective, consecutive chart review was performed on patients who underwent endoscopic skull base reconstruction with a vascularized flap in the setting of intraoperative CSF leaks. In this series, 151 patients with a mean age of 51 years underwent 152 vascularized flap skull base reconstructions for an array of benign and malignant pathologies. These vascularized flaps included 144 nasoseptal flaps, 6 endoscopic-assisted pericranial flaps, 1 facial artery buccinator flap, and 1 inferior turbinate flap that were used throughout all regions of the skull base. Perioperative (< 3 months) and postoperative (> 3 months) flap complications were assessed and revealed 3 perioperative flap defects (2.0%) defined as a visualized defect within the substrate of the flap and a total of 5 perioperative CSF leaks (3.3%). No patient experienced flap death/complete flap loss in the cohort. Assessed postoperative flap complications included 1 case (0.7%) of mucocele formation, 8 cases (5.3%) of prolonged skull base crusting, and 2 cases (1.3%) of donor-site complication, specifically septal perforation secondary to nasoseptal flap harvest. Among the 152 cases identified, 37 patients received radiation therapy while 114 patients did not undergo radiation therapy as part of the treatment profile. No significant association was found between perioperative complication rates and radiation therapy (p = 0.634). However, a significant association was found between postoperative complication rates and radiation therapy, primarily accounted for by an increased risk for prolonged (> 6 months) skull base crusting (p = 0.025). It is clear that larger skull base defects with high intraoperative CSF flow require thoughtful approach and strong consideration for vascularized repair.
Endoscopic endonasal transsphenoidal surgery: implementation of an operative and perioperative checklist
Authors: Christian Eisha , Harris Brianna , Wrobel Bozena , Zada Gabriel
Published: October 2014

Endoscopic endonasal surgery relies heavily on specialized operative instrumentation and optimization of endocrinological and other critical adjunctive intraoperative factors. Several studies and worldwide initiatives have previously established that intraoperative and perioperative surgical checklists can minimize the incidence of and prevent adverse events. The aim of this article was to outline some of the most common considerations in the perioperative and intraoperative preparation for endoscopic endonasal transsphenoidal surgery. The authors implemented and prospectively evaluated a customized checklist at their institution in 25 endoscopic endonasal operations for a variety of sellar and skull base pathological entities. Although no major errors were detected, near misses pertaining primarily to missing components of surgical equipment or instruments were identified in 9 cases (36%). The considerations in the checklist provided in this article can serve as a basic template for further customization by centers performing endoscopic endonasal surgery, where their application may reduce the incidence of adverse or preventable errors associated with surgical treatment of sellar and skull base lesions.
Student feedback about the integrated curriculum in a Caribbean medical school
Authors: Shankar P. Ravi , Balasubramanium Ramanan , Dwivedi Neelam R. , Nuguri Vivek
Published: October 2014

Purpose: Xavier University School of Medicine adopted an integrated, organ system-based curriculum in January 2013. The present study was aimed at determining students’ perceptions of the integrated curriculum and related assessment methods. Methods: The study was conducted on first- to fourth-semester undergraduate medical students during March 2014. The students were informed of the study and subsequently invited to participate. Focus group discussions were conducted. The curriculum’s level of integration, different courses offered, teaching-learning methods employed, and the advantages and concerns relating to the curriculum were noted. The respondents also provided feedback about the assessment methods used. Deductive content analysis was used to analyze the data. Results: Twenty-two of the 68 students (32.2%) participated in the study. The respondents expressed generally positive opinions. They felt that the curriculum prepared them well for licensing examinations and future practice. Problem-based learning sessions encouraged active learning and group work among students, thus, improving their understanding of the course material. The respondents felt that certain subjects were allocated a larger proportion of time during the sessions, as well as more questions during the integrated assessment. They also expressed an appreciation for medical humanities, and felt that sessions on the appraisal of literature needed modification. Their opinions about assessment of behavior, attitudes, and professionalism varied. Conclusion: Student opinion was positive, overall. Our findings would be of interest to other medical schools that have recently adopted an integrated curriculum or are in the process of doing so.
Dorothea Eliza Smith, artist of “The Fruits of the Lima market”
Authors: Vega Fernando E. , Fisher Kimberley , Willis Tony
Published: October 2014

An unpublished collection of watercolours entitled “The Fruits of the Lima market. by Mrs. D. E. Smith, between the years 1850 & ”53” can be credited to Dorothea Eliza Smith (1804–1864), wife of the Scottish physician Archibald Smith (1797–1868) who published Peru as it is. The watercolours were once in the Crewe Hall library and were purchased by Paul and Rachel Mellon in 1957. They are now in the Oak Spring Garden Library in Virginia, USA. The identification of the artist has also revealed fascinating aspects in the life of the Smith family, including a tragedy at sea off the coast of Peru and a personal art collection that included works by van Dyck, Murillo, Jordaens, Andrea del Sarto, and Zurbarán, among others.
The difficult provenance of Ferdinand von Mueller's zoological specimens
Authors: Lucas A. M.
Published: October 2014

The botanist Ferdinand von Mueller (1825–1896) collected few of the very large number of zoological specimens distributed in his name, although museums often record him as the collector. Analysis of his correspondence allows some of the field collectors, and agents who acted between them and Mueller, to be identified, and the provenance of some specimens understood. Not all provenances can be traced, but the analysis of available correspondence cautions against accepting at face value the documentation of surviving specimens.
A Preliminary Study of Muscular Artifact Cancellation in Single-Channel EEG
Authors: Chen Xun , Liu Aiping , Peng Hu , Ward Rabab
Published: October 2014

Electroencephalogram (EEG) recordings are often contaminated with muscular artifacts that strongly obscure the EEG signals and complicates their analysis. For the conventional case, where the EEG recordings are obtained simultaneously over many EEG channels, there exists a considerable range of methods for removing muscular artifacts. In recent years, there has been an increasing trend to use EEG information in ambulatory healthcare and related physiological signal monitoring systems. For practical reasons, a single EEG channel system must be used in these situations. Unfortunately, there exist few studies for muscular artifact cancellation in single-channel EEG recordings. To address this issue, in this preliminary study, we propose a simple, yet effective, method to achieve the muscular artifact cancellation for the single-channel EEG case. This method is a combination of the ensemble empirical mode decomposition (EEMD) and the joint blind source separation (JBSS) techniques. We also conduct a study that compares and investigates all possible single-channel solutions and demonstrate the performance of these methods using numerical simulations and real-life applications. The proposed method is shown to significantly outperform all other methods. It can successfully remove muscular artifacts without altering the underlying EEG activity. It is thus a promising tool for use in ambulatory healthcare systems.
Metabolic Scaling in Complex Living Systems
Authors: Glazier Douglas
Published: October 2014

In this review I show that four major kinds of theoretical approaches have been used to explain the scaling of metabolic rate in cells, organisms and groups of organisms in relation to system size. They include models focusing on surface-area related fluxes of resources and wastes (including heat), internal resource transport, system composition, and various processes affecting resource demand, all of which have been discussed extensively for nearly a century or more. I argue that, although each of these theoretical approaches has been applied to multiple levels of biological organization, none of them alone can fully explain the rich diversity of metabolic scaling relationships, including scaling exponents (log-log slopes) that vary from ~0 to >1. Furthermore, I demonstrate how a synthetic theory of metabolic scaling can be constructed by including the context-dependent action of each of the above modal effects. This “contextual multimodal theory” (CMT) posits that various modulating factors (including metabolic level, surface permeability, body shape, modes of thermoregulation and resource-transport, and other internal and external influences) affect the mechanistic expression of each theoretical module. By involving the contingent operation of several mechanisms, the “meta-mechanistic” CMT differs from most metabolic scaling theories that are deterministically mechanistic. The CMT embraces a systems view of life, and as such recognizes the open, dynamic nature and complex hierarchical and interactive organization of biological systems, and the importance of multiple (upward, downward and reciprocal) causation, biological regulation of resource supply and demand and their interaction, and contingent internal (system) and external (environmental) influences on metabolic scaling, all of which are discussed. I hope that my heuristic attempt at building a unifying theory of metabolic scaling will not only stimulate further testing of all of the various subtheories composing it, but also foster an appreciation that many current models are, at least in part, complementary or even synergistic, rather than antagonistic. Further exploration about how the scaling of the rates of metabolism and other biological processes are interrelated should also provide the groundwork for formulating a general metabolic theory of biology.
A study on the consequence of swift heavy ion irradiation of Zn–silica nanocomposite thin films: electronic sputtering
Authors: Pannu Compesh , Singh Udai B , Agarwal Dinesh C , Khan Saif A , Ojha Sunil , Chandra Ramesh , Amekura Hiro , Kabiraj Debdulal , Avasthi Devesh K
Published: October 2014

Zn–silica nanocomposite thin films with varying Zn metal content, deposited by atom beam sputtering technique were subjected to 100 MeV Ag ion irradiation. Rutherford backscattering spectrometry reveals the loss of Zn with irradiation, which is observed to be greater from thin films with lower Zn content. The sputtered species collected on carbon-coated transmission electron microscopy (TEM) grids consist of Zn nanoparticles of sizes comparable to those present in the nanocomposite thin film. The process of size-dependent electronic sputtering of Zn is explained on the basis of an inelastic thermal spike model. The possibility of direct cluster emission is explained by pressure spike built inside the track, initiated by a temperature spike.
Reversibly locked thionucleobase pairs in DNA to study base flipping enzymes
Authors: Beuck Christine , Weinhold Elmar
Published: October 2014

Covalently interstrand cross-linked DNA is an interesting tool to study DNA binding proteins that locally open up the DNA duplex by flipping single bases out of the DNA helix or melting whole stretches of base pairs to perform their function. The ideal DNA cross-link to study protein–DNA interactions should be specific and easy to synthesize, be stable during protein binding experiments, have a short covalent linker to avoid steric hindrance of protein binding, and should be available as a mimic for both A/T and G/C base pairs to cover all possible binding specificities. Several covalent interstrand cross-links have been described in the literature, but most of them fall short of at least one of the above criteria. We developed an efficient method to site-specifically and reversibly cross-link thionucleoside base pairs in synthetic duplex oligodeoxynucleotides by bisalkylation with 1,2-diiodoethane resulting in an ethylene-bridged base pair. Both linked A/T and G/C base pair analogs can conveniently be prepared which allows studying any base pair-opening enzyme regardless of its sequence specificity. The cross-link is stable in the absence of reducing agents but the linker can be quickly and tracelessly removed by the addition of thiol reagents like dithiothreitol. This property makes the cross-linking reaction fully reversible and allows for a switching of the linked base pair from locked to unlocked during biochemical experiments. Using the DNA methyltransferase from Thermus aquaticus (M.TaqI) as example, we demonstrate that the presented cross-linked DNA with an ethylene-linked A/T base pair analog at the target position is a useful tool to determine the base-flipping equilibrium constant of a base-flipping enzyme which lies mostly on the extrahelical side for M.TaqI.