bluuebunny/crossref_metadata_2025 huggingface dataset:
Automatic Tuning of PSSs and PODs Using a Parallel Differential Evolution Algorithm
Authors: Castoldi Marcelo Favoretto , Júnior Sérgio Carlos Mazucato , Sanches Danilo Sipoli , Rodrigues Carolina Ribeiro , Ramos Rodrigo Andrade
Published: April 2014

Since Electric Power Systems are constantly subjected by perturbations, it is necessary to insert controllers for damping electromechanical oscillations originally from these perturbations. The Power System Stabilizer (PSS) and Power Oscillation Damper (POD) are two of the most common damping controllers used by the industry. However, just the inclusion of these controllers does not guarantee a satisfactory damping of the system, being necessary a good tune of them. This paper proposes a method for simultaneously tuning different kind of controllers considering several operation conditions at once. A differential evolution technique is used to perform the automatic tuning method proposed, with the great advantage of the parallel computing, since modern computers have more than one core. Simulation results with the benchmark test system New England/New York show the satisfactory performance of the parallel algorithm in a short running time than its non-parallel structure.
Open Growth
Authors: Ghafele Roya , Gibert Benjamin
Published: April 2014

Open Source Software (OSS) is well established in sectors as diverse as aviation, health, telecommunications, finance, publishing, education, and government. As nations increasingly rely on knowledge assets to grow, the adoption of OSS will have profound economic consequences. This paper identifies the mechanisms inherent to OSS production that help fuel innovation in knowledge-based economies. As a collaborative and open production model, OSS is conceptualized as a prototype of open innovation. Drawing on US employment projections for 2008-2018, the authors' analysis predicts OSS will have a positive impact on employment growth in well-paid salary jobs across multiple sectors of the US economy. OSS-related software development jobs are widely diffuse throughout the economy, help build a skilled labour force and offer wages significantly above the national average. OSS is thus believed to be a strong contributor to growth in high-value employment in the US. The authors also posit that, as industries are exposed to the benefits of OSS as a result of the broad diffusion of OSS-related jobs, open innovation processes outside software development may be adopted through a process of learning and imitation.
Proposing a Feedback System to Enhance Learning Based on Key Performance Indicators
Authors: Berglund Anders , Blackne Johannes , Jansson Niklas
Published: April 2014

This paper proposes a feedback system that is based on the self-evaluation of perceived productivity as a mechanism for detecting deviations in an engineering design student project. By monitoring key performance indicators, project members used feedback loops to recognize alarming patterns and act accordingly. The study is based on descriptive survey data that addressed three factors of influence: perceived productivity, perception of stage completion, and work-activity distribution. The productivity data was analysed by detecting patterns in the form of peaks and lows and by combining the patterns with qualitative data from observations and documented work activities. Measurements were taken every time the project team got together; 33 occasions during the course of the project, resulting in a total of 280 student responses for productivity (P) and completion (C) and 115 student replies for work activity distribution. The findings provide an extraction of peak values and low values that enables tracking of critical incidents. Through an in-depth activity log, each value was enriched with lessons learned about what took place and the consequences for the project, thus enhancing learning from past activities through systematic feedback sessions. The accumulated set of data provided distinguishable patterns for the project team to interpret. Over time this made student actions more proactive, activity execution more distinct and purposeful, and resource allocation in combination with feedback reflections more refined.
A Multi Agent Based Approach for Critical Components Identification and Testing
Authors: Mala D. Jeya , Iswarya R.
Published: April 2014

In real time software systems, testing plays a crucial role as any of the critical components in these systems are left undetected, then inadvertent effects will happen which will lead to erroneous operations, system failure, high cost and resource wastage etc. To address this most important and the emergent problem, this research work proposes an effective method by means of multi-agents based approach to identify such critical components and execute test cases along the critical test paths which will aid in effectively covering them during testing. Finally, this paper also compared the performance with existing approaches in terms of time taken for the search process and the component coverage based test adequacy criterion to ensure quality of the software.
Destination to Nowhere: A New Look at Aggressive Treatment for Heart Failure—A Case Study
Authors: O’Neill Brian J. , Kazer Meredith W.
Published: April 2014

Approximately 5.7 million people in the United States experience heart failure, and about 670 000 new cases are diagnosed annually. Patients who are ineligible for heart transplant may benefit from a left ventricular assist device. These devices have provided patients with an increased life span, but eventually patients die of the underlying heart disease. This case study illustrates the appropriate use of palliative care teams to address preparedness planning and help decrease moral distress among nursing staff. (Critical Care Nurse. 2014; 34[2]:47–56)
Differential Ability of Surface and Endosomal TLRs To Induce CD8 T Cell Responses In Vivo
Authors: Mandraju Rajakumar , Murray Sean , Forman James , Pasare Chandrashekhar
Published: April 2014

TLR activation on dendritic cells (DCs) induces DC maturation and secretion of proinflammatory cytokines, both of which are important for activation and differentiation of CD4 T cells. The importance of TLR activation on DCs for CD8 T cell responses is less clear. In this study, we tested the ability of different TLRs to regulate CD8 T cell responses to pathogens. We found that although all TLRs are able to induce CD8 T cell activation in vitro, there are profound differences in their ability to activate CD8 T cells in vivo. The nucleic acid recognizing endosomal TLRs, TLR3 and TLR9, had a potent ability to induce CD8 T cell activation. However, the surface TLRs, TLR2 and TLR4, that recognize bacterial ligands were not only incapable of inducing CD8 T cell priming, but they had a dominant effect of inhibiting CD8 T cell expansion induced by activation of endosomal TLRs. We found that TLR2 and TLR4, acting in a MyD88-dependent manner, influenced CD8 T cell priming by altering the composition of DCs in the draining lymph nodes. Our results have important implications for combined bacterial and viral infections and suggest that bacterial infections could constrain the ability of the host to mount effective antiviral CD8 T cell immunity.
The impact of packaging, price and brand awareness on brand loyalty: Evidence from the paint retailing industry
Authors: Dhurup Manilall , Mafini Chengedzai , Dumasi Tshepiso
Published: April 2014

Purpose: The purpose of the study was to investigate the impact of packaging, price and brand awareness on brand loyalty.Rationale: The study sought to extend empirical evidence on the association between brand loyalty and product-related factors: packaging, price and brand awareness.Methodology: The study adopted a quantitative survey approach and was conducted in a paint retailing environment. Data were elicited from a conveniently selected sample of 212 consumers who purchased various brands of paint. Regression analysis and the one-way analysis of variance test were conducted to investigate the impact of packaging, price and brand awareness on brand loyalty.Findings: Packaging, price and brand awareness showed significant positive relationships with brand loyalty, which implied their significant predictive influence on brand loyalty. The results suggest that management should, inter alia, initiate and implement effective packaging, pricing and brand awareness in order to enhance consumers’ brand loyalty to the company’s products.Value of research: The research provides valuable insights to managers of companies on the need to continuously enhance their products’ packaging with competitive pricing strategies in order to improve brand awareness and brand loyalty and remain competitive in the market. The study also provides evidence of the relationship between brand loyalty and packaging, price and brand awareness in a South African context.Conclusion: The marketing success of businesses depends on their ability to continuously enhance their products’ packaging with competitive pricing and brand awareness strategies in order to improve brand loyalty. Future studies should be extended to other retailing environments and product categories.
‘Simply my own’
Authors: Moolman Kobus
Published: April 2014

No abstract available.
Mall shopping preferences and patronage of mature shoppers
Authors: Rousseau Gabriel G. , Venter Daniel J.L.
Published: April 2014

Orientation: Retailers often consider other market segments ahead of mature consumers because they perceive that they have limited purchasing power. This study addressed this misperception by investigating the buying behaviour of mature consumers.Research purpose: The purpose of this study was to investigate the buying behaviour of mature consumers (older than 55) in Port Elizabeth shopping malls.Motivation for the study: The perception of mature shoppers as old people with limited financial resources is untrue. This study investigates the behaviours of mature shoppers.Research design, approach and method: A model guided the investigation. The authors facilitated four focus groups to gain insight into mature consumers’ buying behaviours. A field survey followed with a sample of mall shoppers (n = 680). The authors performed content analysis of the focus group material and used SPSS and AMOS programs to analyse the data quantitatively.Main findings: Focus group interviews revealed specific buying behaviours of mature shoppers. The survey showed significant relationships between various determinants that influence respondents’ buying behaviours with adequate model fit indices. These results confirmed the convergent and discriminant validity of the model that comprises mall shopping anticipation, experience and patronage.Practical/managerial implications: Mature shoppers’ expectations exceeded their experiences, suggesting dissatisfaction with some aspects of their experiences. Retailers and shopping mall managers need to redesign malls if they wish to cater for the segment of ageing shoppers and their spending power.Contribution/value-add: The study contributes to the research available in South Africa on service at shopping malls that cater for mature consumers.
Gynaecomastia correction: A review of our experience
Authors: Mohan Arvind , Khan Muhammad Adil Abbas , Srinivasan Karthik , Roberts Jeremy
Published: March 2014

Introduction: Gynaecomastia is a common problem in the male population with a reported prevalence of up to 36%. Various treatment techniques have been described but none have gained universal acceptance. We reviewed all gynaecomastia patients operated on by one consultant over a 7-year period to assess the morbidity and complication rates associated with the procedure. Materials and Methods: Clinical notes and outpatient records of all patients who underwent gynaecomastia correction at University Hospital North Staffordshire between 01/10/2001 to 01/10/2009 were retrospectively reviewed. A modified version of the Breast Evaluation Questionnaire was used to assess patients satisfaction with the procedure. Results: Twenty-nine patients and a total of 53 breasts were operated on during the study period. Patients underwent either liposuction alone (6 breasts - 11.3%), excision alone (37 breasts - 69.8%) or both excision and liposuction (10 breasts - 18.9%). Twelve operated breasts (22.6%) experienced some form of complication. Minor complications included seroma (2 patients), superficial wound dehiscence (2 patients) and minor bleeding not requiring theatre (3 patients). Two patients developed haematomas requiring evacuation in theatre. No cases of wound infection, major wound dehiscence or revision surgery were encountered. Twenty-six patients (89.7%) returned the patient satisfaction questionnaire. Patients scored an average 4.12 with regards comfort of their chest in different settings, 3.98 with regards chest appearance in different settings, and 4.22 with regards satisfaction levels for themselves and their partner/family. Overall complication rate was 22.6%. Grade III patients experienced the highest complication rate (35.7%), followed by grade II (22.7%) and grade I (17.6%). Overall complication rates among the excision only group was the highest (29.8%) followed by the liposuction only group (16.7%) and the liposuction and excision group (10.0%). There were high satisfaction rates amongst both patients and surgeon. Eleven patients (37.9%) had their outcome classified as ‘excellent’ by the operating surgeon, 16 patients (55.2%) as ‘good’, 1 (3.4%) as ‘satisfactory’ and 1(3.4%) as ‘poor’. Conclusion: Gynaecomastia is a complex condition which poses a significant challenge to the plastic surgeon. Despite the possible complications our case series demonstrates that outcomes of operative correction can be favourable and yield high levels of satisfaction from both patient and surgeon.
Inter-observer reliability of clinical measurement of suprasternal notch-nipple distance and breast ptosis
Authors: Hansson Emma , Manjer Jonas , Ringberg Anita
Published: March 2014

Context: Suprasternal notch-nipple distance and breast ptosis are two measurements that are often used in everyday plastic surgical clinical practice. Nonetheless, the reliability of standard breast measurements has never been tested. Aim: The aim of the present study was to test the inter-observer reliability of clinical measurement of ptosis and suprasternal notch-nipple distance. Settings and Design: Six raters measured ptosis and suprasternal notch-nipple distance in 12 breasts on the same day. Statistical Analysis Used: Intra-class correlation (ICC) coefficients, the coefficient of variation (CV) and Bland-Altman plots. Results and Conclusions: The results show that there is certain variation between different raters. The ICC of average measures between raters is 0.92 for the ptosis and 0.94 for the suprasternal notch-nipple distance, that is, the agreement between different raters is high. According to the Bland—Altman plots, the overall assessment of the comparisons of measurements between the different raters shows that the direction of the mean differences is close to zero. This study shows that there is a good reliability for measurements of suprasternal notch-nipple distance and ptosis. Nonetheless, there is a slight inter-rater variability in the measurements. Even though standardised, measurement of breasts is not an exact science and care has to be taken when the measurements are performed. The surgeon should have this in mind when measurements are used in clinical practice to evaluate breasts and to choose the right surgical method, as well as when guidelines for indications for surgery are set up.
Leaf spotting reaction of spring common, durum and spelt wheat, and Kamut under organic management in western Canada
Authors: Fernandez M. R. , Fox S. L. , Hucl P. , Singh A. K.
Published: March 2014

Fernandez, M. R., Fox, S. L., Hucl, P. and Singh, A. K. 2014. Leaf spotting reaction of spring common, durum and spelt wheat, and Kamut under organic management in western Canada. Can. J. Plant Sci. 94: 929–935. A 3-yr field study (2010 to 2012) was conducted in southwest Saskatchewan to determine the reaction of common, durum and spelt wheat cultivars currently registered in western Canada, and of Kamut wheat, to the leaf spot disease complex (LS) under organic management. The genotypes selected for this study are often grown by organic producers in this region. Overall, the most common LS diseases observed had been observed in previous studies under conventional management in the same area. For all 3 yr, common wheat cultivars with the highest LS scores were AC Barrie, CDC Go, Superb, and Unity, while those with the lowest scores were AC Andrew, CDC Bounty and Lillian. For durum wheat, Kyle had overall the greatest LS scores. CDC Zorba had lower LS scores than the other spelt wheat, CDC Origin, and it also had the lowest LS levels of all genotypes in this study. Kamut wheat was similar to the common and durum wheat cultivars for LS severity. The relative presence of the most common LS pathogens isolated (Pyrenophora tritici-repentis, Phaeosphaeria nodorum, Phaeosphaeria avenaria f. sp. triticea, Cochliobolus sativus, Mycosphaerella graminicola) from each of the four wheat species in each of the three years is also presented and discussed.
Transmission of Onchocerca volvulus by Simulium neavei in Mount Elgon Focus of Eastern Uganda Has Been Interrupted
Authors: Katabarwa Moses , Lakwo Tom , Habomugisha Peace , Agunyo Stella , Byamukama Edson , Oguttu David , Ndyomugyenyi Richard , Tukesiga Ephraim , Ochieng Galex Orukan , Abwaimo Francis , Onapa Ambrose , Lwamafa Dennis W. K. , Walsh Frank , Unnasch Thomas R. , Richards Frank O.
Published: April 2014

The study determined that Simulium neavei-transmitted onchocerciasis in Mount Elgon onchocerciasis focus had been interrupted. Annual mass treatment with ivermectin changed to two times per year along with vector elimination in 2007. Then, baseline microfilaria (mf) prevalence data of 1994 in five sentinel communities were compared with follow-up data in 2005 and 2011. Blood spots from 3,051 children obtained in 2009 were analyzed for Onchocerca volvulus immunoglobulin G4 antibodies. Fresh water crab host captures and blackflies collected indicated their infestation with larval stages of S. neavei and presence or absence of the vector, respectively. Mf rates dropped from 62.2% to 0.5%, and 1 (0.03%) of 3,051 children was positive for O. volvulus antibodies. Crab infestation dropped from 41.9% in 2007 to 0%, and S. neavei biting reduced to zero. Both remained zero for the next 3 years, confirming interruption of onchocerciasis transmission, and interventions were halted.
Identification of Risk Factors for Plague in the West Nile Region of Uganda
Authors: Eisen Rebecca J. , MacMillan Katherine , Atiku Linda A. , Mpanga Joseph T. , Zielinski-Gutierrez Emily , Graham Christine B. , Boegler Karen A. , Enscore Russell E. , Gage Kenneth L.
Published: April 2014

Plague is an often fatal, primarily flea-borne rodent-associated zoonosis caused by Yersinia pestis. We sought to identify risk factors for plague by comparing villages with and without a history of human plague cases within a model-defined plague focus in the West Nile Region of Uganda. Although rat (Rattus rattus) abundance was similar inside huts within case and control villages, contact rates between rats and humans (as measured by reported rat bites) and host-seeking flea loads were higher in case villages. In addition, compared with persons in control villages, persons in case villages more often reported sleeping on reed or straw mats, storing food in huts where persons sleep, owning dogs and allowing them into huts where persons sleep, storing garbage inside or near huts, and cooking in huts where persons sleep. Compared with persons in case villages, persons in control villages more commonly reported replacing thatch roofing, and growing coffee, tomatoes, onions, and melons in agricultural plots adjacent to their homesteads. Rodent and flea control practices, knowledge of plague, distance to clinics, and most care-seeking practices were similar between persons in case villages and persons in control villages. Our findings reinforce existing plague prevention recommendations and point to potentially advantageous local interventions.
Post-apartheid transnationalism in black South African literature: a reality or a fallacy?
Authors: Rafapa Lesibana
Published: March 2014

The quest of this paper is to probe whether globalising post-nationalism impacts on post- apartheid black South African English literature in a manner that suggests a blurring of distinctive African identities. This is done against the background that black South African literature right from its written beginnings in the early 19th century has coalesced into a taxonomically distinct entity forming a non-negligible component of South African literature written in English. I first analyse two post-apartheid novels written by the black writers Niq Mhlongo (Dog Eat Dog, 2004) and Sindiwe Magona (Beauty’s Gift, 2008). Secondly, I consider three post-apartheid novels by the black writers Phaswane Mpe (Welcome to Our Hillbrow, 2001), Kgebetli Moele (Room 207, 2009) and Kopano Matlwa (Coconut, 2007). I approach an examination of the five post-apartheid novels by separating them into two categories, as a way of indicating that black South African literature of this era remains as stylistically varied as that of earlier periods, albeit broadly within a mould continuing to characterise it as black. In order to justify an underlying common allegiance to localised identity cutting across the two categories in which I place these five post-apartheid novels, evidence of such a pervasively black feature is explained inter-categorically, even as intra-categorical affinities are demonstrated. I trace these two levels of typology within the conceptual framework of two main groups of theorists. The first group consists of commentators such as Carrol Clarkson in her assertion that the identity of black Africans in the post-apartheid era as portrayed in the fiction of writers such as Phaswane Mpe is such that “educated and urbanised individuals should no longer identify” with and share beliefs having to do with African identity and “a common and accountable response to that which the community represents.” The attitude of these critics has led to Leon de Kock seeing both black and white post-apartheid literature warranting interpretation with a “sense of a post-national configuration—indeed, now a transnational constellation.” I demonstrate in this paper that post-apartheid fiction written by blacks not only defies theorists’ subordination of imaginative writers’ centrality in social discourse, but goes further specifically to chafe against normative characterisation as transnational. The second main category constituting the theoretical matrix within which I examine the discourses of the five selected novels includes theorists such as Rob Gaylard, in his observation that Es’kia Mphahlele “can be seen as the founder of a tradition of black writing that runs through writers like Miriam Tlali, Mtutuzeli Matshoba, Njabulo Ndebele and Zakes Mda to Phaswane Mpe,” with the thread splicing them together being a grounding of these authors’ writings in the philosophy or worldview of Afrikan Humanism.
Introduction: Orality and technauriture of African literatures
Authors: Merolla Daniela
Published: March 2014

African oral cultures as well as their oral literatures are vigorous. True, in some cases, elements of such literatures are at risk of disappearing when styles and texts are linked to specific languages and rituals that are no longer performed as they were in the past; in other cases, the very limited number of speakers has drawn local and global attention to endangered languages and the need for their revitalization Still, such a “sense of an ending” needs to be balanced by the observation that the large majority of the verbal arts and the cultural groups that produce them have, by and large, integrated oral and new ways of expression—from hip hop to various forms of theatre, world fusion music and digital orality. Changing oral genres and “technauriture” in African literatures are at the heart of the analyses and discussions presented in this number of Tydskrif vir Letterkunde. The included articles derive from the 9th Conference of ISOLA (International Society for the Oral Literatures of Africa) held at the University of Venda (South Africa) from June 28 to July 1, 2012.
Origin, variability and age of biomass burning plumes intercepted during BORTAS-B
Authors: Finch D. P. , Palmer P. I. , Parrington M.
Published: March 2014

Abstract. We use the GEOS-Chem atmospheric chemistry transport model to interpret aircraft measurements of carbon monoxide (CO) in biomass burning outflow taken during the 2011 BORTAS-B campaign over eastern Canada. The model has some skill reproducing the observed variability (r = 0.45) but has a negative bias for observations below 100 ppb and a positive bias above 300 ppb. We find that observed CO variations are largely due to NW North American biomass burning, as expected, with smaller and less variable contributions from fossil fuel combustion from eastern Asia and NE North America. To help interpret observed variations of CO we develop an Eulerian effective age of emissions (A) metric, accounting for mixing and chemical decay, which we apply to pyrogenic emissions of CO. We find that during BORTAS-B the age of emissions intercepted over Halifax, Nova Scotia is typically 4–11 days, and on occasion as young as two days. We show that A is typically 1–5 days older than the associated photochemical ages inferred from colocated measurements of different hydrocarbons. We find that the median difference between the age measures (Δτ) in plumes (CH3CN > 150 ppt) peaks at 3–5 days corresponding to a chemical retardation of 50%. We find a strong relationship in plumes between A and Δτ (r2 = 0.60), which is not evident outwith these plumes (r2 = 0.23). We argue that these observed relationships, together with a robust observed relationship between CO and black carbon aerosol during BORTAS-B (r2 > 0.7), form the basis of indirect evidence that aerosols co-emitted with gases during pyrolysis markedly slowed down the plume photochemistry during BORTAS-B with respect to photochemistry at the same latitude and altitude in clear skies.
Lightning NOx, a key chemistry–climate interaction: impacts of future climate change and consequences for tropospheric oxidising capacity
Authors: Banerjee A. , Archibald A. T. , Maycock A. , Telford P. , Abraham N. L. , Yang X. , Braesicke P. , Pyle J.
Published: March 2014

Abstract. Lightning is one of the major natural sources of NOx in the atmosphere. A suite of time-slice experiments using a stratosphere-resolving configuration of the Unified Model (UM), containing the UK Chemistry and Aerosols sub-model (UKCA), have been performed to investigate the impact of climate change on lightning produced NOx (LNOx) and to highlight its critical impacts on photochemical ozone production and the oxidising capacity of the troposphere. Two Representative Concentration Pathway (RCP) scenarios (RCP4.5 and RCP8.5) are explored. LNOx emissions are simulated to increase in a year-2100 climate by 33% (RCP4.5) and 78% (RCP8.5) in response to changes in convection. The total tropospheric chemical odd oxygen production (P(Ox)) increases linearly with total LNOx emissions and consequently, the tropospheric ozone burden also increases by 29 ± 4 Tg(O3) (RCP4.5) and 46 ± 4 Tg(O3) (RCP8.5). We thus show that, through changes in LNOx, the effects of climate change counteract the simulated mitigation of the ozone burden, which results from reductions in ozone precursor emissions as part of air quality controls projected in the RCP scenarios. Without the driver of increased LNOx, our simulations suggest that the net effect of climate change would be to lower free tropospheric ozone. In addition, we identify large climate-change induced enhancements in the concentration of the hydroxyl radical (OH) in the tropical upper troposphere (UT), particularly over the Maritime Continent, primarily as a consequence of larger LNOx emissions. The OH enhancement in the tropics increases oxidation of both methane (with feedbacks onto chemistry and climate) and very short-lived substances (VSLS) (with implications for stratospheric ozone depletion). We emphasise that it is important to improve our understanding of LNOx in order to gain confidence in model projections of future climate.
Relative role of bed roughness change and bed erosion on peak discharge increase in hyperconcentrated floods
Authors: Li W. , Wang Z. B. , van Maren D. S. , de Vriend H. J. , Wu B. S.
Published: April 2014

Abstract. River floods are usually featured by a downstream flattening discharge peak whereas a downstream increasing discharge peak is observed at a rate exceeding the tributary discharge during highly silt-laden floods (hyperconcentrated floods) in China's Yellow River. It entails a great challenge in the downstream flood defence and the underlying mechanisms need to be unravelled. Previous study on this issue only focuses on one possible mechanism, while the present work aims to reveal the relative importance of bed roughness change and bed erosion in the hyperconcentrated flood. Using a newly developed fully coupled morphodynamic model, we have conducted a numerical study for the 2004 hyperconcentrated flood in the Xiaolangdi-Jiahetan reach of the Lower Yellow River. In order to focus on the physical mechanism and to reduce uncertainty from low-resolution topography data, the numerical modeling was carried out in a schematized 1-D channel of constant width. The basic understanding that bed roughness decreases with concentration at moderate concentrations (e.g. several 10 s to 100 s g L−1) was incorporated by a simple power-law relation between Manning roughness coefficient and sediment concentration. The feedback between the bed deformation and the turbid flow, however, was fully accounted for, in the constituting equations as well as in the numerical solutions. The model successfully reproduced the downstream flood peak increase for the 2004 flood when considering the hyperconcentration-induced bed roughness reduction. As the hyperconcentration lags shortly behind the flood peak, later parts of the flood wave may experience less friction and overtake the wave front, leading to the discharge increase. In comparison, bed erosion is much less important to the discharge increase, at least for hyperconcentrated flood of moderate sediment concentration.
Hydrodynamics of a small trained tidal inlet (Currumbin Creek, Australia)
Authors: Shaeri S. , Tomlinson R. B. , Etemad-Shahidi A. , Strauss D. , Hughes L. P.
Published: April 2014

Abstract. Small tidal inlets are important features of coastal areas, in terms of provision of access from a back barrier water-body to the ocean as well as periodic circulation of fresh nutrients for the local ecology. Usually, dimensional and geometrical characteristics contribute significantly to morphological stability or instability of a particular inlet and necessitate an individual investigation of any desired location. In other words, generalized usage of previous empirical and experimental research of a different position can hardly be used for other places. In this regard, one of the powerful tools to understand the physical processes of a particular region is to collect as much field data as possible. Such a dataset is used to further analyse and explore the governing processes and can also be used for building a numerical computer model for supplementary studies. In this research, the results of a comprehensive field measurement at Currumbin Creek, Queensland, Australia are presented. This study is part of broader research to investigate the long term evolution of the Currumbin entrance and its adjacent beaches. Currently, an annual dredging campaign is needed to reduce the risk of flooding due to excess rainfall inundations and to maintain water quality. The majority of data were collected over a three month period consistent with the time of the 2012 dredging operation. However, due to the loss of some instrumentation, data collection for some of the parameters was repeated till the middle of May 2013. All collected data included: (1) nearshore waves and tide; (2) creek tidal variation; (3) creek flow discharge and velocity; (4) bathymetric survey of the creek; (5) beach profile evolution survey; and (6) sediment sampling. The measurement showed that the creek entrance is tidally dominated, with flood events having a major role in sediment transport into the creek. The nearshore stations' wave data illustrated the marginal effect of the beach curvature between updrift and downdrift stations. Thus, the historical dataset available from the updrift wave rider buoy will be selected to be used for future numerical modelling. Although changes of some beach profiles were comparatively insignificant, the dramatic changes of the profile lines nearby the inlet channel and also rapid bathymetric change of the flood shoal following the dredging completion are valuable information to better calibrate and interpret a local sediment modelling study for the next phase. Essentially, this evaluation needs to be considered for proposing any alternative maintenance activities.
Morphodynamic modelling for the entire German Bight: an initial study on model sensitivity and uncertainty
Authors: Plüß A. , Kösters F.
Published: April 2014

Abstract. Morphodynamic modelling of coastal seas and estuaries for large-scale and long-term applications is strongly affected by parameter sensitivity of process-based models. Moreover, the comparison of data-based methods with numerical model results is limited by uncertainties in measurements. These drawbacks can be partly overcome by a multi-model approach (MMA). In a case study to assess long-term sediment transport and morphodynamic processes for the German Bight, the AufMod research project applies two different methods for process-based modelling: UnTRIM-SediMorph and DELFT3D. Model sensitivity is illustrated in terms of different morphological changes for diverse porosity values. As a first step, discrepancies between individual methods are shown based on resulting sediment transport patterns.
Distribution of ammonia oxidizers in relation to vegetation characteristics in the Qilian Mountains, northwestern China
Authors: Tai X. S. , Mao W. L. , Liu G. X. , Chen T. , Zhang W. , Wu X. K. , Long H. Z. , Zhang B. G. , Gao T. P.
Published: April 2014

Abstract. Nitrogen is the major limiting nutrient in cold environments, and its availability is strongly dependent on nitrification. However, microbial communities driving this process remain largely uncharacterized in alpine meadow soils in northwestern China, namely those catalyzing the rate-limiting step of ammonia oxidation. In this study, ammonia-oxidizing communities in alpine meadow soils were characterized by real-time PCR and clone sequencing by targeting on amoA genes, which putatively encode ammonia monooxygenase subunit A. The results demonstrated that ammonia-oxidizing archaea (AOA) outnumbered ammonia-oxidizing bacteria (AOB) in the alpine meadow soils. Most of the AOA phylotypes detected in the study region fell within typical Group I.1b of Thaumarchaeota. Interestingly, a new ammonia-oxidizing archaeal group named "Kobresia meadow soil group" was found. Phylogenetic analysis of AOB communities exhibited a dominance of Nitrosospira-like sequences affiliated to beta-Proteobacteria. Compared with other alpine environments, Qilian Mountains had a great phylogenetic diversity of ammonia oxidizers. Principal Component Analysis (PCA) analysis showed that distinct AOA/AOB phylotype groups were attributed to different meadow types, reflecting an overall distribution of ammonia-oxidizing communities associated with meadow types. Redundancy Analysis (RDA) analysis showed that Axis 1 (90.9%) together with Axis 2 (9.1%) explained all the variables while Axis 1 exhibited a significant explanatory power. So that vegetation coverage mostly correlated to Axis 1 was the most powerful environmental factor in the study region. Characteristics of ammonia-oxidizing communities showed a close association with vegetation coverage.
Flexible C : N ratio enhances metabolism of large phytoplankton when resource supply is intermittent
Authors: Talmy D. , Blackford J. , Hardman-Mountford N. J. , Polimene L. , Follows M. J. , Geider R. J.
Published: April 2014

Abstract. Phytoplankton cell size influences particle sinking rate, food web interactions and biogeographical distributions. We present a model in which the uptake, storage and assimilation of nitrogen and carbon are explicitly resolved in different sized phytoplankton cells. In the model, metabolism and cellular C : N ratio are influenced by accumulation of carbon polymers such as carbohydrate and lipid, which is greatest when cells are nutrient starved, or exposed to high light. Allometric relations and empirical datasets are used to constrain the range of possible C : N, and indicate larger cells can accumulate significantly more carbon storage compounds than smaller cells. When forced with extended periods of darkness combined with brief exposure to saturating irradiance, the model predicts organisms large enough to accumulate significant carbon reserves may on average synthesize protein and other functional apparatus up to five times faster than smaller organisms. The advantage of storage in terms of average daily protein synthesis rate is greatest when modeled organisms were previously nutrient starved, and carbon storage reservoirs saturated. Small organisms may therefore be at a disadvantage in terms of average daily growth rate in environments that involve prolonged periods of darkness and intermittent nutrient limitation. We suggest this mechanism is a significant constraint on phytoplankton C : N variability and cell size distribution in different oceanic regimes.
On the sensitivity of 3-D thermal convection codes to numerical discretization: a model intercomparison
Authors: Arrial P.-A. , Flyer N. , Wright G. B. , Kellogg L. H.
Published: April 2014

Abstract. Fully 3-D numerical simulations of thermal convection in a spherical shell have become a standard for studying the dynamics of pattern formation and its stability under perturbations to various parameter values. The question arises as to how does the discretization of the governing equations affect the outcome and thus any physical interpretation. This work demonstrates the impact of numerical discretization on the observed patterns, the value at which symmetry is broken, and how stability and stationary behavior is dependent upon it. Motivated by numerical simulations of convection in the Earth's mantle, we consider isoviscous Rayleigh-Bénard convection at infinite Prandtl number, where the aspect ratio between the inner and outer shell is 0.55. We show that the subtleties involved in development mantle convection models are considerably more delicate than has been previously appreciated, due to the rich dynamical behavior of the system. Two codes with different numerical discretization schemes: an established, community-developed, and benchmarked finite element code (CitcomS) and a novel spectral method that combines Chebyshev polynomials with radial basis functions (RBF) are compared. A full numerical study is investigated for the following three cases. The first case is based on the cubic (or octahedral) initial condition (spherical harmonics of degree ℓ =4). How variations in the behavior of the cubic pattern to perturbations in the initial condition and Rayleigh number between the two numerical discrezations is studied. The second case investigates the stability of the dodecahedral (or icosahedral) initial condition (spherical harmonics of degree ℓ = 6). Although both methods converge first to the same pattern, this structure is ultimately unstable and systematically degenerates to cubic or tetrahedral symmetries, depending on the code used. Lastly, a new steady state pattern is presented as a combination of order 3 and 4 spherical harmonics leading to a five cell or a hexahedral pattern and stable up to 70 times the critical Rayleigh number. This pattern can provide the basis for a new accuracy benchmark for 3-D spherical mantle convection codes.
Assessment of Cortical Dysfunction in Infantile Esotropia Using fMRI
Authors: Yang Xubo , Zhang Junran , Lang Lijuan , Gong Qiyong , Liu Longqian
Published: April 2014

Purpose

Functional magnetic resonance imaging (fMRI) is popular in the field of neuroimaging. The aim of this study was to explore the neural basis of infantile esotropia and locate the cortical region of fusion function defects using blood oxygen level—dependent fMRI (BOLD-fMRI).

Methods

Subjects (5 with infantile esotropia and 8 normal) were presented with a visual stimulus (letter E). The BOLD-fMRI was used to measure the visual cortex response as the distance between the E and the eyes changing from 20 to 100 cm using a block experimental design. Data were processed offline using statistical parametric mapping and compared between the 2 groups.

Results

Areas activated in the visual cortex of normal subjects were located in the bilateral frontal gyrus and left lingual visual cortex (p<0.001). The BOLD signal in the left cingulate gyrus, bilateral precuneus, and left angular gyrus was higher in the infantile esotropia group than in the controls (p<0.001). None of the visual cortical areas showed higher signal in the control individuals than in those with infantile esotropia (p<0.001).

Conclusions

The bilateral frontal gyrus and left lingual visual cortex regulate normal fusion function in human eyes. In infantile esotropia, the left cingulate gyrus, bilateral precuneus, and left angular gyrus visual cortex may compensate for the fusion dysfunction. These insights may help improve the diagnosis and treatment of strabismus.
Optical and Visual Simulation of Standard and Modified Spherical Aberration Implantable Collamer Lens Post Myopic LASIK Surgery
Authors: Pérez-Vives Cari , Belda-Salmerón Lurdes , García-Lázaro Santiago , Ferrer-Blasco Teresa , Montés-Micó Robert
Published: April 2014

Purpose

To evaluate the visual quality achieved in patients undergoing standard or modified implantable Collamer lens (ICL) to correct residual myopic error after laser-assisted in situ keratomileusis (LASIK) surgery.

Methods

The adaptive optics visual simulator was used to simulate LASIK surgery of moderate and high myopia with a myopic regression corrected by a standard and modified ICL. Visual acuity (VA) and contrast sensitivity (CS) were measured in 14 subjects at 3- and 4.5-mm pupil. Point spread function and simulated retinal images were calculated.

Results

Comparing LASIK plus standard ICL and LASIK plus modified ICL simulations, for moderate myopia, VA improvement was less than 1 line in all VA contrasts and both pupils evaluated. No statistically significant differences were found in CS between the simulations at any spatial frequency evaluated and for 3-mm pupil (p>0.05), but differences were significant at 4.5-mm pupil (p<0.05). For high myopia, the VA improvement was less than 1 line at 3-mm pupil, although it increased 2 or more lines at 4.5-mm pupil. Statistically significant differences were found in CS between the simulations for all spatial frequencies and both pupils evaluated (p<0.05), except for low and medium spatial frequencies at 3-mm pupil (p>0.05).

Conclusions

These outcomes suggest that an ICL is a good option to correct the myopic residual error after myopic LASIK. When the ICL's spherical aberration is modified, the post-LASIK eyes of high myopia are the most benefited, as these eyes are more aberrated than after moderate myopic LASIK.
Increased Central Corneal Thickness in Patients with Turner Syndrome
Authors: Nalcacioglu-Yüksekkaya Pinar , Sen Emine , Onder Asan , Cetinkaya Semra , Tos Tulay , Kurtul Ece , Aycan Zehra
Published: April 2014

Purpose

To evaluate central corneal thickness (CCT) values in patients with Turner syndrome (TS) and compare these values with healthy subjects.

Methods

A total of 31 subjects with TS and 67 age- and sex-matched healthy subjects made up the study and control group, respectively. The CCT values were measured by an ultrasound pachymeter in this cross-sectional prospective study. The ocular findings were recorded. We also evaluated to effect of karyotype analysis, recombinant growth hormone therapy (GHT), and mean duration of treatment on the CCT parameter in patients with TS.

Results

The mean CCT values were 582.0 ± 40.8 μm (490-648) in the TS and 549.1 ± 34.6 μm (494-601) in the healthy group. The mean intraocular pressure (IOP) by Goldmann applanation tonometry was 16.3 ± 3.1 mm Hg (9-22) in the TS and 15.2 ± 2.5 mm Hg (10-21) in the healthy group. The mean CCT value was significantly higher in the TS group (p<0.05) but there was no statistically significant difference between the 2 groups for IOP (p>0.05). There was also no significant difference for CCT regarding the karyotype, GHT use, and mean duration of treatment in patients with TS (p>0.05).

Conclusions

Central corneal thickness values should be considered during measurement of IOP in individuals with TS as these values may be higher than in healthy subjects.
Clinical Features of Patients with Episcleritis and Scleritis in an Italian Tertiary Care Referral Center
Authors: Berchicci Luigi , Miserocchi Elisabetta , Di Nicola Maura , La Spina Carlo , Bandello Francesco , Modorati Giulio
Published: April 2014

Purpose

To evaluate demographic characteristics, clinical features, systemic disease associations, visual outcomes, and treatment modalities of patients with episcleritis and scleritis in an Italian tertiary care referral center.

Methods

Data from 25 patients with episcleritis and from 85 patients with scleritis followed from 2003 to 2012 were retrospectively evaluated. The main outcome measures were demographics, ocular disease characteristics, presence of systemic associated disease, treatment regimen, and follow-up period.

Results

Episcleritis and scleritis were found bilaterally in 24% and 31% of patients, respectively (p<0.521). The episcleritis was diffuse in 15 and focal in 10 patients, while the scleritis was diffuse in 49, nodular in 28, necrotizing in 6, and posterior in 2 patients. Anterior uveitis (4% vs 31%; p<0.006), peripheral ulcerative keratitis (0% vs 14%; p<0.167), ocular hypertension (0% vs 7%; p<0.333), and a decrease in visual acuity (4% vs 19%; p<0.112) were encountered as ocular complications in patients with episcleritis and patients with scleritis, respectively. An associated systemic disease was found in 20% and 52% of patients with episcleritis and patients with scleritis (p<0.004). Among patients with episcleritis, 76% required topical corticosteroid treatment to achieve disease resolution, 16% oral nonsteroidal anti-inflammatory drugs (NSAIDs), and 8% antivirals; 39% of patients with scleritis required systemic NSAIDs, 12% oral corticosteroids, 34% immunosuppressive drugs, and 15% antibiotics or antivirals.

Conclusions

The importance of differentiating scleritis from episcleritis is remarkable given the significant difference in the degree of ocular complications and associated systemic diseases between these ocular conditions. Prompt diagnosis, systemic assessment, and treatment are fundamental in all patients with scleral inflammation.