bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysing the Returns-Earnings Relationship
Authors: Beynon Malcolm J. , Clatworthy Mark
Published: January 2013

This chapter considers the problem of understanding the relationship between company stock returns and earnings components, namely accruals and cash flows. The problem is of interest, because earnings are a key output of the accounting process, and investors have been shown to depend heavily on earnings in their valuation models. This chapter offers an elucidation on the application of a nascent data analysis technique, the Classification and Ranking Belief Simplex (CaRBS) and a recent development of it, called RCaRBS, in the returns-earnings relationship problem previously described. The approach underpinning the CaRBS technique is closely associated with uncertain reasoning, with methodological rudiments based on the Dempster-Shafer theory of evidence. With the analysis approach formed as a constrained optimisation problem, details on the employment of the evolutionary computation based technique trigonometric differential evolution are also presented. Alongside the presentation of results, in terms of model fit and variable contribution, based on a CaRBS classification-type analysis, a secondary analysis is performed using a development RCaRBS, which is able to perform multivariate regression-type analysis. Comparisons are made between the results from the two different types of analysis, as well as briefly with more traditional forms of analysis, namely binary logistic regression and multivariate linear regression. Where appropriate, numerical details in the construction of results from both CaRBS and RCaRBS are presented, as well emphasis on the graphical elucidation of findings.
Pure and Hybrid Metaheuristics for the Response Time Variability Problem
Authors: García-Villoria Alberto , Corominas Albert , Pastor Rafael
Published: January 2013

Metaheuristics are a powerful tool for solving hard optimisation problems. Moreover, metaheuristic hybrid optimisation techniques can be applied to develop an improved metaheuristic algorithm for a given problem. It is known that some metaheuristics perform better than others for each problem. However, there is a lack of theoretical basis to explain why a metaheuristic performs well (or bad) when solving a problem, and there is not a general guide to design specific hybrid metaheuristics. In this chapter, the authors describe the response time variability problem (RTVP), which is an NP-hard combinatorial optimisation problem that appears in a wide range of engineering and business applications. They show how to solve this problem by means of metaheuristics and how to design specific hybrid metaheuristics for the RTVP. This may be useful to managers, engineers, researchers, and scientists to deal with other types of optimisation problems.
ANN-Based Self-Tuning Frequency Control Design for an Isolated Microgrid
Authors: Bevrani H. , Habibi F. , Shokoohi S.
Published: January 2013

The increasing need for electrical energy, limited fossil fuel reserves, and the increasing concerns with environmental issues call for fast development in the area of distributed generations (DGs) and renewable energy sources (RESs). A Microgrid (MG) as one of the newest concepts in the power systems consists of several DGs and RESs that provides electrical and heat power for local loads. Increasing in number of MGs and nonlinearity/complexity due to entry of MGs to the power systems, classical and nonflexible control structures may not represent desirable performance over a wide range of operating conditions. Therefore, more flexible and intelligent optimal approaches are needed. Following the advent of optimization/intelligent methods, such as artificial neural networks (ANNs), some new potentials and powerful solutions for MG control problems such as frequency control synthesis have arisen. The present chapter addresses an ANN-based optimal approach scheduling of the droop coefficients for the purpose of frequency regulation in the MGs.
Soccer Game Optimization
Authors: Purnomo Hindriyanto Dwi , Wee Hui-Ming
Published: January 2013

A new metaheuristic algorithm is proposed. The algorithm integrates the information sharing as well as the evolution operators in the swarm intelligence algorithm and evolutionary algorithm respectively. The basic soccer player movement is used as the analogy to describe the algorithm. The new method has two basic operators; the move off and the move forward. The proposed method elaborates the reproduction process in evolutionary algorithm with the powerful information sharing in the swarm intelligence algorithm. Examples of implementations are provided for continuous and discrete problems. The experiment results reveal that the proposed method has the potential to become a powerful optimization method. As a new method, the proposed algorithm can be enhanced in many different ways such as investigating the parameter setting, elaborating more aspects of the soccer player movement as well as implementing the proposed method to solve various optimization problems.
Two Stage Capacitated Facility Location Problem
Authors: Litvinchev Igor , Mata Miguel , Ozuna Lucero , Saucedo Jania , Rangel Socorro
Published: January 2013

In the two-stage capacitated facility location problem, a single product is produced at some plants in order to satisfy customer demands. The product is transported from these plants to some depots and then to the customers. The capacities of the plants and depots are limited. The aim is to select cost minimizing locations from a set of potential plants and depots. This cost includes fixed cost associated with opening plants and depots, and variable cost associated with both transportation stages. In this work two different mixed integer linear programming formulations are considered for the problem. Several Lagrangian relaxations are analyzed and compared, a Lagrangian heuristic producing feasible solutions is presented. The results of a computational study are reported.
Usage of Metaheuristics in Engineering
Authors: Senvar Ozlem , Turanoglu Ebru , Kahraman Cengiz
Published: January 2013

A metaheuristic is conventionally described as an iterative generation process which guides a servient heuristic by combining intelligently different concepts for exploring and exploiting the search space, learning strategies are used to structure information in order to find efficiently near-optimal solutions. In the literature, usage of metaheuristic in engineering problems is increasing in a rapid manner. In this study; a survey of the most important metaheuristics from a conceptual point of view is given. Background knowledge for each metaheuristics is presented. The publications are classified with respect to the used metaheuristic techniques and application areas. Advantages and disadvantages of metaheuristics can be found in this chapter. Future directions of metaheuristics are also mentioned.
Online Clustering and Outlier Detection
Authors: Wang Baoying , Dong Aijuan
Published: January 2013

Clustering and outlier detection are important data mining areas. Online clustering and outlier detection generally work with continuous data streams generated at a rapid rate and have many practical applications, such as network instruction detection and online fraud detection. This chapter first reviews related background of online clustering and outlier detection. Then, an incremental clustering and outlier detection method for market-basket data is proposed and presented in details. This proposed method consists of two phases: weighted affinity measure clustering (WC clustering) and outlier detection. Specifically, given a data set, the WC clustering phase analyzes the data set and groups data items into clusters. Then, outlier detection phase examines each newly arrived transaction against the item clusters formed in WC clustering phase, and determines whether the new transaction is an outlier. Periodically, the newly collected transactions are analyzed using WC clustering to produce an updated set of clusters, against which transactions arrived afterwards are examined. The process is carried out continuously and incrementally. Finally, the future research trends on online data mining are explored at the end of the chapter.
Application of Meta-Heuristic Optimization Algorithms in Electric Power Systems
Authors: Voropai N.I. , Gamm A. Z. , Glazunova A. M. , Etingov P. V. , Kolosok I. N. , Korkina E. S. , Kurbatsky V. G. , Sidorov D. N. , Spiryaev V. A. , Tomin N. V. , Zaika R. A. , Bat-Undraal B.
Published: January 2013

Optimization of solutions on expansion of electric power systems (EPS) and their control plays a crucial part in ensuring efficiency of the power industry, reliability of electric power supply to consumers and power quality. Until recently, this goal was accomplished by applying classical and modern methods of linear and nonlinear programming. In some complicated cases, however, these methods turn out to be rather inefficient. Meta-heuristic optimization algorithms often make it possible to successfully cope with arising difficulties. State estimation (SE) is used to calculate current operating conditions of EPS using the SCADA measurements of state variables (voltages, currents etc.). To solve the SE problem, the Energy Systems Institute of Siberian Branch of Russian Academy of Sciences (ESI of SB RAS) has devised a method based on test equations (TE), i.e. on the steady state equations that contain only measured parameters. Here, a technique for EPS SE using genetic algorithms (GA) is suggested. SE is the main tool for EPS monitoring. The quality of SE results determines largely the EPS control efficiency. An algorithm for exclusion of wrong SE calculations is described. The algorithm using artificial neural networks (ANN) is based on the analysis of results of the calculation performed solving the SE problem with different combinations of constants. The proposed procedure is checked on real data.
A Gravitational Search Algorithm Approach for Optimizing Closed-Loop Logistics Network
Authors: Sadrnia Abdolhossein , Nezamabadi-Pour Hossein , Nikbakht Mehrdad , Ismail Napsiah
Published: January 2013

Since late in the 20th century, various heuristic and metaheuristic optimization methods have been developed to obtain superior results and optimize models more efficiently. Some have been inspired by natural events and swarm behaviors. In this chapter, the authors illustrate empirical applications of the gravitational search algorithm (GSA) as a new optimization algorithm based on the law of gravity and mass interactions to optimize closed-loop logistics network. To achieve these aims, the need for a green supply chain will be discussed, and the related drivers and pressures motivate us to develop a mathematical model to optimize total cost in a closed-loop logistic for gathering automobile alternators at the end of their life cycle. Finally, optimizing total costs in a logistic network is solved using GSA in MATLAB software. To express GSA capabilities, a genetic algorithm (GA), as a common and standard metaheuristic algorithm, is compared. The obtained results confirm GSA’s performance and its ability to solve complicated network problems in closed-loop supply chain and logistics.
Team Learning and Reflexivity in Technology-Mediated Collaboration
Authors: Andres Hayward P.
Published: January 2013

This study examines technological, educational/learning, and social affordances associated with the facilitation of team learning during technology-mediated collaborative problem solving. An empirical interpretive research approach using direct observation is used to interpret, evaluate and rate observable manifested behaviors and qualitative content (i.e., discussions) associated with team learning and team reflexivity. The theory of affordances and social impact theory are integrated to develop a conceptual model that asserts that collaboration mode (collocated vs. non-collocated and videoconferencing supported) will dictate the quality of information exchange, progressive elaboration of ideas, and the social processes that influence team learning. Team learning is then suggested to give rise to task and social reflexivity behaviors aimed at monitoring and evaluating acquired understanding, adaptation of task strategy, and maintenance of quality intra-team interactions. Results showed that collocated teams did engage in better quality team learning behaviors. Further, persistent reflection on task progress and solution accuracy yielded better team productivity while maintenance of a mutual supportive and positive climate yielded higher perceived quality interpersonal interactions. Theoretical, methodological and practical implications of the study are also discussed.
The Anonymity of the Internet
Authors: Rovie Eric M.
Published: January 2013

Commerce performed electronically using the Internet (e-commerce) faces a unique and difficult problem, the anonymity of the Internet. Because the parties are not in physical proximity to one another, there are limited avenues for trust to arise between them, and this leads to the fear of cheating and promise-breaking. To resolve this problem, I explore solutions that are based on Thomas Hobbes’s solutions to the problem of the free rider and apply them to e-commerce.
The Development of ICT for Envisioning Cloud Computing and Innovation in South Asia
Authors: Abu Sheikh Taher , Tsuji Masatsugu
Published: January 2013

This paper examines the implications of cloud computing in South Asia in relation to ICT deployment. The authors employ empirical analysis based on related literatures and an ICT panel dataset from 1999-2007, to discover significant factors in this field. Evidence from several studies has shown that the deployment of ICT is greatly related to improvements in a country’s economic performance. The study thus focuses on how ICT deployment helps South Asian countries to adopt cloud computing concepts and innovations, such as Web 2.0, Health 2.0 or Education 2.0. ICT penetration differs from country to country in several respects, except with regard to mobile phones. The study therefore generates new ideas, first, to increase capacity and add capabilities based on mobile technology to adopt the concepts of Web 2.0, Health 2.0 or Education 2.0 throughout South Asia, and, second, to re-think ICT deployment and encourage the diffusion of cloud computing and technological innovation. The paper concludes its analysis with suggestions for policy in developing countries.
Non-target Gelechiidae and Noctuidae attraction toAroga trialbamaculella(Lepidoptera: Gelechiidae) pheromone-based trapping systems
Authors: Kelly Jillian A. , Avery Trevor S. , Stewart Donald T. , Cutler Christopher G. , Gaul Sonia O. , MacKenzie Kenna E. , Hillier N. Kirk
Published: January 2013

Cucullia umbraticaLinnaeus (Lepidoptera: Noctuidae),Agnippe prunifoliellaChambers (Lepidoptera: Gelechiidae), andBryotropha plantariellaTengstrom (Lepidoptera: Gelechiidae), were significant bycatch in pheromone-based trapping systems for red-striped fireworm,Aroga trialbamaculellaChambers (Lepidoptera: Gelechiidae), in Nova Scotia, Canada.Cucullia umbraticais a European introduced species and a new macrolepidopteran recorded in continental Canada. The only previous record of this moth in North America was from the Magdalen Islands (Québec, Canada). Potential attractants forB. plantariella,A. prunifoliella, andC. umbraticaare a result of this bycatch investigation.
Tim-3/Galectin-9 Regulate the Homeostasis of Hepatic NKT Cells in a Murine Model of Nonalcoholic Fatty Liver Disease
Authors: Tang Zhao-Hui , Liang Shuwen , Potter James , Jiang Xuan , Mao Hai-Quan , Li Zhiping
Published: January 2013

T cell Ig and mucin domain (Tim)-3 is well known to interact with its natural ligand, Galectin-9 (Gal-9), to regulate T cell function. However, little is known about the function of Tim-3/Gal-9 signaling in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) mediated by hepatic NKT cells that also express Tim-3. In the current study, we define the role and the mechanism of Tim-3/Gal-9 signaling in hepatic NKT cell regulation in a mouse model of diet-induced NAFLD. Adult male wild-type or CD1d knockout C57BL/6 mice were fed a high-fat diet to induce steatosis. Some of the mice also received one or a combination of Gal-9, anti–IL-15R/IL-15 mAb, rIL-15, α-galactosylceramide, and multilamellar liposomes containing Cl2MDP. The expression of Tim-3 and various markers reflecting cell proliferation, activation, cytokine production, and apoptosis was analyzed. Liver histology, steatosis grade, and hepatic triglyceride content were also evaluated. In the liver, Tim-3+ NKT cells are in an activated state, and Gal-9 directly induces Tim-3+ NKT cell apoptosis and contributes to the depletion of NKT cells in diet-induced steatosis. However, Gal-9 also interacts with Tim-3–expressing Kupffer cells to induce secretion of IL-15, thus promoting NKT cell proliferation. Exogenous administration of Gal-9 significantly ameliorates diet-induced steatosis by modulating hepatic NKT cell function. In summary, the Tim-3/Gal-9–signaling pathway plays a critical role in the homeostasis of hepatic NKT cells through activation-induced apoptosis and secondary proliferation and, thus, contributes to the pathogenesis of NAFLD.
High Frequency of Human Blood in Triatoma dimidiata Captured Inside Dwellings in a Rural Community in the Yucatan Peninsula, Mexico, but Low Antibody Seroprevalence and Electrocardiographic Findings Compatible with Chagas Disease in Humans
Authors: Monteon Victor , Alducin César , Hernández Jorge , Ramos-Ligonio Angel , Lopez Ruth
Published: January 2013

We studied a small rural community of 411 inhabitants localized in the state of Campeche in the Yucatan Peninsula, Mexico. In 44 collected triatomines captured inside the houses, human feeding source was revealed in 23 of 44 (52%) samples, and chicken feeding source was revealed in 16 of 44 (36%) samples. In a set of 29 triatomines, mouse was the feeding source in 13 (44%) samples, and dog was the feeding source in 7 (24%) samples. Infection index with Trypanosoma cruzi in collected triatomines was 38%, and all parasites belonged to discrete type unit I. Inhabitants referred high contact with triatomine's bite in 60 of 128 (47%) samples, but seroprevalence was 2.3% (3/128). Evidence of electrocardiographic alteration compatible with Chagas disease was observed only in one asymptomatic seropositive subject. In conclusion, Triatoma dimidiata in this region are preferentially infected with T. cruzi I and feed on human beings with relative high frequency, but seroprevalence and Chagas disease in humans is relatively low.
Advantages of EMBEDA® (morphine sulfate and naltrexone hydrochloride) extended-release capsules in pain management
Authors: Kapoor, MD Shailendra
Published: January 2013

No abstract
Postsurgical patient-controlled opioid self-administration is greater in hospitalized abstinent smokers than nonsmokers
Authors: Steinmiller, PhD Caren L. , Diederichs, BS Christina , Roehrs, PhD Timothy A. , Hyde-Nolan, MS Maren , Roth, PhD Thomas , Greenwald, PhD Mark K.
Published: January 2013

Objective: To compare 24-hour postsurgical patient-controlled analgesia (PCA) in smokers and nonsmokers.Design: Patients completed a presurgical questionnaire inquiring about sleep, nicotine and other substance use, and comorbid disorders. Nicotine use was discontinued on hospital admission on the day of surgery. After morning surgery and (spinal) anesthesia recovery, each patient began opioid PCA with a device that limited dose frequency (morphine 1 mg equivalent units) using a lockout period (range, 6-10 minutes).Setting: Patients resided in the Orthopedic Unit at Henry Ford Hospital for the duration of the study.Patients: Cigarette smokers (n = 13) and healthy nonsmokers (n = 13) who completed the presurgical questionnaire were matched for age, gender, and type of surgery (hip vs knee replacement).Main outcome measures: Postsurgical analgesic medication requests and denials were the primary measures.Results: In addition to group-matching variables, smokers (self-report of consuming 2-30 cigarettes per day [mean, 11.7]) and nonsmokers did not significantly differ in average weight, height, body mass index, surgery start time (about 9:45 AM), PCA start time (about 4 PM), or lockout interval (8.6 minutes). More smokers (n = 11) than nonsmokers (n = 5) received opioids during recovery before PCA (χ2 = 5.85, p < 0.05). During PCA, smokers had significantly more injection denials [F(1,24) = 4.65, p < 0.05] and fewer infusions per request [F(1,24) = 6.74, p < 0.05] than nonsmokers. During nighttime hours, smokers had significantly more infusion requests [F(1,24) = 4.41, p < 0.05] and more injection denials [F(1,24) = 5.67, p < 0.03] than nonsmokers.Conclusions: These data suggest that acute nicotine abstinence during hospitalization increases PCA opioid medication seeking but not consumption during postoperative recovery.
Risk assessment and counseling behaviors of healthcare professionals managing patients with chronic pain: A national multifaceted assessment of physicians, pharmacists, and their patients
Authors: Salinas, PhD Gregory D. , Susalka Debi , Burton, MS B. Stephen , Roepke, MBA Nancy , Evanyo Kimberly , Biondi, DO David , Nicholson, MD Susan
Published: January 2013

Introduction: Due to the significant and increasing problem of chronic pain in the United States, pain management is a frequent need in many healthcare settings. At the same time, there has been rising concern with the abuse/misuse and potential for addiction to opioid therapies. This study was conducted to better understand healthcare professionals’ current knowledge, perceptions, and clinical practice patterns regarding prescribing of extended-release or long-acting opioid therapy to patients with chronic pain.Methods: This study was conducted from March 2011 to May 2011; it utilized a nationally distributed case vignette survey of primary care physicians (PCPs), pain specialists, and pharmacists, along with nested chart reviews and surveys of patients with chronic pain.Results: Many PCPs are inadequately performing opioid risk assessments and there is variability in interpreting a patient’s opioid risk, resulting in misestimated risk. Physicians underutilize urine drug screens and written opioid use agreements when initiating opioid therapy in patients. Physicians and pharmacists often omit key messages during patient counseling about safe use of opioids and safe medication storage. Among pharmacists, safety counseling is generally limited to alerting patients to potential side effects. For most PCPs, difficulty managing patients with risk factors for opioid use and uncertainty about managing first line opioid efficacy failure are significant barriers to effective management of chronic pain.Conclusions: Patients having chronic pain and concomitant risk factors for opioid abuse, misuse, and diversion are prevalent, yet many physicians, especially PCPs, are uncomfortable managing opioid therapy in such patients. Education on best practices for risk assessment, patient monitoring during treatment, strategies for more effective counseling, patient chart documentation, and management strategies to enhance effective treatment of chronic pain are essential to ensure that PCPs and specialists maximize effective and safe use of opioid medications. Pharmacists could be a valuable member of this interdisciplinary team and should be involved in patient counseling and monitoring for aberrant behavior.
Characteristics of prescribers whose patients shop for opioids: Results from a cohort study
Authors: Cepeda, MD, PhD M. Soledad , Fife, MD Daniel , Berlin, ScD Jesse A. , Mastrogiovanni, BS Gregory , Yuan, PhD Yingli
Published: January 2013

Background: Little is known about the prevalence of opioid shoppers in clinical practices and the relation between prescriber characteristics and the risk of having opioid shoppers.Objective: Describe the prevalence of opioid shoppers in prescribers’ practices. Assess the relation between prescribers’ characteristics and patient opioid shopping behavior.Design: Retrospective cohort study using a large US retail prescription database. Patients, Participants: Patients with ≥1 opioid dispensing were followed 18 months. These patients’ prescribers are the focus of the study.Main Outcome Measures: A patient was a “shopper” if he or she had opioid prescriptions written by ≥1 prescriber with ≥1 day of overlap filled at ≥3 pharmacies and a “heavy shopper” if he or she had ≥5 shopping episodes. The proportions of shoppers by prescriber and the proportion of prescribers with ≥1 shopper or heavy shopper were calculated.Results: Among 858,290 opioid prescribers, most (87 percent) had no shoppers and 98 percent had no heavy shoppers. Prescribers who were aged 70-79 years, male, or who prescribed schedule II opioids had an increased likelihood of having shoppers. As the number of patients for whom a prescriber prescribed opioids increased, the proportion of shoppers also increased. Prescribers with 66 or more patients receiving opioids, who represented 25 percent of prescribers, prescribed for 82 percent of all shoppers.Conclusion: The great majority of opioid prescribers appear to have no shoppers in their practice. Any educational program will be more cost effective if targeted to prescribers of schedule II opioids with a large volume of patients requiring opioids.
High opioid dosage rapid detoxification of cancer patient in palliative care with the Raffaeli model
Authors: Monterubbianesi, MD Maria Cristina , Capuccini, MD Jenny , Ferioli, MD Isabella , Tassinari, MD Davide , Sarti, PhD Donatella , Raffaeli, MD William
Published: January 2013

Background: Chronic opioid administration can induce adverse drug-dependent events and tolerance and/or hyperalgesia development. Opioid rotation is the treatment option in this case; however, it can expose patients to long periods of ineffectiveness and/or development of withdrawal syndrome, overdose, or adverse events. To overcome this issue, a method of rapid detoxification from opioids has been developed.Aims: To assess feasibility and efficacy of our opioid detoxification protocol in patients affected from chronic cancer pain.Settings/Patients: We studied 15 patients, with chronic cancer pain, who were afferent to Hospice of Rimini, Italy, were in therapy with high doses of opioid and needed opioid rotation or a therapeutic variation because of opioid toxicity, inefficacy, tolerance, or hyperalgesia. Each patient received a fixed dose of endovenous morphine and clonidine plus oral ketoprofen or ibuprofen, and oral lorazepam, if required, for at least 3 days, suspending the previous opioid therapy. We monitored withdrawal symptoms, pain intensity, type, and intensity of adverse events. Results: Withdrawal symptoms were experienced by four (26.6 percent) patients. The average Numerical Rating Scale for pain decreased significantly (p < 0.05) from 8.3 ± 1.57 to 3.6 ± 1.4 at the end of the detoxification and to 2.4 ± 1 at the end of the rotation or therapeutic adjustment. Average duration of the detoxification was 6.86 ± 6.4 days (range 3-22).Conclusions: The results suggested that the detoxification protocol may be effective in preventing withdrawal signs in patients needing a therapeutic change because of opioid-induced tolerance, hyperalgesia, or toxicity.
On the relationship between total ozone and atmospheric dynamics and chemistry at mid-latitudes – Part 1: Statistical models and spatial fingerprints of atmospheric dynamics and chemistry
Authors: Frossard L. , Rieder H. E. , Ribatet M. , Staehelin J. , Maeder J. A. , Di Rocco S. , Davison A. C. , Peter T.
Published: January 2013

Abstract. We use statistical models for mean and extreme values of total column ozone to analyze "fingerprints" of atmospheric dynamics and chemistry on long-term ozone changes at northern and southern mid-latitudes on grid cell basis. At each grid cell, the r-largest order statistics method is used for the analysis of extreme events in low and high total ozone (termed ELOs and EHOs, respectively), and an autoregressive moving average (ARMA) model is used for the corresponding mean value analysis. In order to describe the dynamical and chemical state of the atmosphere, the statistical models include important atmospheric covariates: the solar cycle, the Quasi-Biennial Oscillation (QBO), ozone depleting substances (ODS) in terms of equivalent effective stratospheric chlorine (EESC), the North Atlantic Oscillation (NAO), the Antarctic Oscillation (AAO), the El Niño/Southern Oscillation (ENSO), and aerosol load after the volcanic eruptions of El Chichón and Mt. Pinatubo. The influence of the individual covariates on mean and extreme levels in total column ozone is derived on a grid cell basis. The results show that "fingerprints", i.e., significant influence, of dynamical and chemical features are captured in both the "bulk" and the tails of the statistical distribution of ozone, respectively described by mean values and EHOs/ELOs. While results for the solar cycle, QBO, and EESC are in good agreement with findings of earlier studies, unprecedented spatial fingerprints are retrieved for the dynamical covariates. Column ozone is enhanced over Labrador/Greenland, the North Atlantic sector and over the Norwegian Sea, but is reduced over Europe, Russia and the Eastern United States during the positive NAO phase, and vice-versa during the negative phase. The NAO's southern counterpart, the AAO, strongly influences column ozone at lower southern mid-latitudes, including the southern parts of South America and the Antarctic Peninsula, and the central southern mid-latitudes. Results for both NAO and AAO confirm the importance of atmospheric dynamics for ozone variability and changes from local/regional to global scales.
Relationship between level of neutral buoyancy and dual-Doppler observed mass detrainment levels in deep convection
Authors: Mullendore G. L. , Homann A. J. , Jorgenson S. T. , Lang T. J. , Tessendorf S. A.
Published: January 2013

Abstract. Although it is generally accepted that the level of neutral buoyancy (LNB) is only a coarse estimate of updraft depth, the LNB is still used to understand and predict storm structure in both observations and modeling. This study uses case studies to quantify the variability associated with using environmental soundings to predict detrainment levels. Nine dual-Doppler convective cases were used to determine the observed level of maximum detrainment (LMD) to compare with the LNB. The LNB for each case was calculated with a variety of methods and with a variety of sources (including both observed and simulated soundings). The most representative LNB was chosen as the proximity sounding from NARR using the most unstable parcel and including ice processes. The observed cases were a mix of storm morphologies, including both supercell and multicell storms. As expected, the LMD was generally below the LNB, the mean offset for all cases being 2.2 km. However, there was a marked difference between the supercell and non-supercell cases. The two supercell cases had LMDs of 0.3 km and 0.0 km below the LNB. The remaining cases had LMDs that ranged from 4.0 km below to 1.6 km below the LNB, with a mean offset of 2.8 km below. Observations also showed that evolution of the LMD over the lifetime of the storm can be significant (e.g., >2 km altitude change in 30 min), and this time evolution is lacking from models with coarse time steps, missing significant changes in detrainment levels that may strongly impact the amount of boundary layer mass transported to the upper troposphere and lower stratosphere.
Dynamic evaluation of a multi-year model simulation of particulate matter concentrations over Europe
Authors: Lecœur È. , Seigneur C.
Published: January 2013

Abstract. A nine-year air quality simulation is conducted from 2000 to 2008 over Europe using the Polyphemus/Polair3D chemical-transport model (CTM) and then evaluated against the measurements of the European Monitoring and Evaluation Programme (EMEP). The spatial distribution of PM2.5 over Europe shows high concentrations over northern Italy (36 μg m−3) and some areas of eastern Europe, France, and Benelux, and low concentrations over Scandinavia, Spain, and the easternmost part of Europe. PM2.5 composition differs among regions. The operational evaluation shows satisfactory model performance for ozone (O3). PM2.5, PM10, and sulfate (SO42−) meet the performance goal of Boylan and Russell (2006). Nitrate (NO3−) and ammonium (NH4+) are overestimated, although NH4+ meets the performance criteria. The correlation coefficients between simulated and observed data are 63% for O3, 57% for PM10, 59% for PM2.5, 57% for SO42−, 42% for NO3−, and 58% for NH4+. The comparison with other recent one-year model simulations shows that all models overestimate nitrate. The performance of PM2.5, sulfate, and ammonium is comparable to that of the other models. The dynamic evaluation shows that the response of PM2.5 to changes in meteorology differs depending on location and the meteorological variable considered. Wind speed and precipitation show a strong negative day-to-day correlation with PM2.5 and its components (except for sea salt, which shows a positive correlation), that tends towards 0 as the day lag increases. On the other hand, the correlation coefficient is near constant for temperature, for any day lag and PM2.5 species, but it may be positive or negative depending on the species and, for sulfate, depending on the location. The effects of precipitation and wind speed on PM2.5 and its components are better reproduced by the model than the effects of temperature. This is mainly due to the fact that temperature has different effects on the PM2.5 components, unlike precipitation and wind speed which impact most of the PM2.5 components in the same way. These results suggest that state-of-the-science air quality models reproduce satisfactorily the effect of meteorology on PM2.5 and, therefore, are suitable to investigate the effects of climate change on particulate air quality.
Modeling the surface tension of complex, reactive organic-inorganic mixtures
Authors: Schwier A. N. , Viglione G. A. , Li Z. , McNeill V. F.
Published: January 2013

Abstract. Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as cloud condensation nuclei (CCN) ability. We present new experimental data for the surface tension of complex, reactive organic-inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2–6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well-described by a weighted Szyszkowski–Langmuir (S–L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling because the Henning model (using data obtained from organic-inorganic systems) and Tuckermann approach provide similar modeling fits and goodness of fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.
Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from 224Ra measurements
Authors: Burt W. J. , Thomas H. , Fennel K. , Horne E.
Published: January 2013

Abstract. Exchanges between sediment pore waters and the overlying water column play a significant role in the chemical budgets of many important chemical constituents. Direct quantification of such benthic fluxes requires explicit knowledge of the sediment properties and biogeochemistry. Alternatively, changes in water-column properties near the sediment-water interface can be exploited to gain insight into the sediment biogeochemistry and benthic fluxes. Here, we apply a 1-D diffusive mixing model to near-bottom water-column profiles of 224Ra activity in order to yield vertical eddy diffusivities (KZ), based upon which we assess the diffusive exchange of dissolved inorganic carbon (DIC), nutrients and oxygen (O2), across the sediment-water interface in a coastal inlet, Bedford Basin, Nova Scotia, Canada. Numerical model results are consistent with the assumptions regarding a constant, single benthic source of 224Ra, the lack of mixing by advective processes, and a predominantly benthic source and sink of DIC and O2, respectively, with minimal water-column respiration in the deep waters of Bedford Basin. Near-bottom observations of DIC, O2 and nutrients provide flux ratios similar to Redfield values, suggesting that benthic respiration of primarily marine organic matter is the dominant driver. Furthermore, a relative deficit of nitrate in the observed flux ratios indicates that denitrification also plays a role in the oxidation of organic matter, although its occurrence was not strong enough to allow us to detect the corresponding AT fluxes out of the sediment. Finally, comparison with other carbon sources reveal the observed benthic DIC release as a significant contributor to the Bedford Basin carbon system.
Sea-air CO2 fluxes in the Southern Ocean for the period 1990–2009
Authors: Lenton A. , Tilbrook B. , Law R. , Bakker D. , Doney S. C. , Gruber N. , Hoppema M. , Ishii M. , Lovenduski N. S. , Matear R. J. , McNeil B. I. , Metzl N. , Mikaloff Fletcher S. E. , Monteiro P. , Rödenbeck C. , Sweeney C. , Takahashi T.
Published: January 2013

Abstract. The Southern Ocean (44° S–75° S) plays a critical role in the global carbon cycle, yet remains one of the most poorly sampled ocean regions. Different approaches have been used to estimate sea-air CO2 fluxes in this region: synthesis of surface ocean observations, ocean biogeochemical models, and atmospheric and ocean inversions. As part of the RECCAP (REgional Carbon Cycle Assessment and Processes) project, we combine these different approaches to quantify and assess the magnitude and variability in Southern Ocean sea-air CO2 fluxes between 1990–2009. Using all models and inversions (26), the integrated median annual sea-air CO2 flux of −0.42 ± 0.07 Pg C yr−1 for the 44° S–75° S region is consistent with the −0.27 ± 0.13 Pg C yr−1 calculated using surface observations. The circumpolar region south of 58° S has a small net annual flux (model and inversion median: −0.04 ± 0.07 Pg C yr−1 and observations: +0.04 ± 0.02 Pg C yr−1), with most of the net annual flux located in the 44° S to 58° S circumpolar band (model and inversion median: −0.36 ± 0.09 Pg C yr−1 and observations: −0.35 ± 0.09 Pg C yr−1). Seasonally, in the 44° S–58° S region, the median of 5 ocean biogeochemical models captures the observed sea-air CO2 flux seasonal cycle, while the median of 11 atmospheric inversions shows little seasonal change in the net flux. South of 58° S, neither atmospheric inversions nor ocean biogeochemical models reproduce the phase and amplitude of the observed seasonal sea-air CO2 flux, particularly in the Austral Winter. Importantly, no individual atmospheric inversion or ocean biogeochemical model is capable of reproducing both the observed annual mean uptake and the observed seasonal cycle. This raises concerns about projecting future changes in Southern Ocean CO2 fluxes. The median interannual variability from atmospheric inversions and ocean biogeochemical models is substantial in the Southern Ocean; up to 25% of the annual mean flux with 25% of this inter-annual variability attributed to the region south of 58° S. Trends in the net CO2 flux from the inversions and models are not statistically different from the expected increase of –0.05 Pg C yr−1 decade−1 due to increasing atmospheric CO2 concentrations. However, resolving long term trends is difficult due to the large interannual variability and short time frame (1990–2009) of this study.
Limitations of microbial hydrocarbon degradation at the Amon Mud Volcano (Nile Deep Sea Fan)
Authors: Felden J. , Lichtschlag A. , Wenzhöfer F. , de Beer D. , Feseker T. , Pop Ristova P. , de Lange G. , Boetius A.
Published: January 2013

Abstract. The Amon mud volcano (MV), located at 1250 m water depth on the Nile Deep Sea Fan, is known for its active emission of methane and non-methane hydrocarbons into the hydrosphere. Previous investigations showed a low efficiency of hydrocarbon-degrading anaerobic microbial communities inhabiting the Amon MV center in the presence of sulphate and hydrocarbons in the seeping subsurface fluids. By comparing spatial and temporal patterns of in situ biogeochemical fluxes, temperature gradients, pore water composition and microbial activities over three years, we investigated why the activity of anaerobic hydrocarbon degraders can be low despite high energy supplies. We found that the central dome of the Amon MV, as well as a lateral mud flow at its base, showed signs of recent exposure of hot subsurface muds lacking active hydrocarbon degrading communities. In these highly disturbed areas, anaerobic degradation of methane was less than 2% of the methane flux. Rather high oxygen consumption rates compared to low sulphide production suggest a faster development of more rapidly growing aerobic hydrocarbon degraders in highly disturbed areas. In contrast, the more stabilized muds surrounding the central gas and fluid conduits hosted active anaerobic hydrocarbon-degrading microbial communities. Furthermore, within three years, cell numbers and hydrocarbon degrading activity increased at the gas-seeping sites. The low microbial activity in the hydrocarbon-vented areas of Amon mud volcano is thus a consequence of kinetic limitations by heat and mud expulsion, whereas most of the outer mud volcano area is limited by hydrocarbon transport.
Sensitivity analysis and calibration of a soil carbon model (SoilGen2) in two contrasting loess forest soils
Authors: Yu Y. Y. , Finke P. A. , Wu H. B. , Guo Z. T.
Published: January 2013

Abstract. To accurately estimate past terrestrial carbon pools is the key to understanding the global carbon cycle and its relationship with the climate system. SoilGen2 is a useful tool to obtain aspects of soil properties (including carbon content) by simulating soil formation processes; thus it offers an opportunity for both past soil carbon pool reconstruction and future carbon pool prediction. In order to apply it to various environmental conditions, parameters related to carbon cycle process in SoilGen2 are calibrated based on six soil pedons from two typical loess deposition regions (Belgium and China). Sensitivity analysis using the Morris method shows that decomposition rate of humus (kHUM), fraction of incoming plant material as leaf litter (frecto) and decomposition rate of resistant plant material (kRPM) are the three most sensitive parameters that would cause the greatest uncertainty in simulated change of soil organic carbon in both regions. According to the principle of minimizing the difference between simulated and measured organic carbon by comparing quality indices, the suited values of kHUM, (frecto and kRPM in the model are deduced step by step and validated for independent soil pedons. The difference of calibrated parameters between Belgium and China may be attributed to their different vegetation types and climate conditions. This calibrated model allows more accurate simulation of carbon change in the whole pedon and has potential for future modeling of carbon cycle over long timescales.
Inertia–gravity waves generated by near balanced flow in 2-layer shallow water turbulence on the β-plane
Authors: Wirth A.
Published: January 2013

Abstract. Using a fine resolution numerical model (40002 × 2 grid-points) of the two-layer shallow-water equations of the mid-latitude β-plane dynamics, it is shown that there is no sudden breakdown of balance in the turbulent enstrophy cascade but a faint and continuous emission of inertia–gravity waves. The wave energy accumulates in the equator-ward region of the domain due to the Coriolis parameter depending on the latitude and dispersion relation of inertia–gravity waves.
Evaluation of Corneal Elevation in Eyes with Subclinical Keratoconus and Keratoconus using Galilei Double Scheimpflug Analyzer
Authors: Jafarinasab Mohammad Reza , Feizi Sepehr , Karimian Farid , Hasanpour Hossein
Published: January 2013

Purpose

TO measure corneal elevations in eyes with subclinical keratoconus and those with keratoconus using the Galilei Scheimpflug analyzer and to determine the optimal corneal elevation cutoff points to maximize sensitivity and specificity in discriminating keratoconus and subclinical keratoconus from normal corneas.

Methods

A total of 136 normal eyes, 23 eyes with subclinical keratoconus, and 51 eyes with keratoconus were enrolled. Maximum anterior and posterior corneal elevation was measured in the central 3-, 5-, and 7-mm zones using the Galilei double Scheimpflug camera. Receiver operating characteristic curves were used to compare the sensitivity and specificity of the measured parameters and to identify optimal cutoff points for discriminating keratoconus and subclinical keratoconus from normal corneas.

Results

Mean anterior and posterior corneal elevations in all zones were statistically higher in keratoconus and subclinical keratoconus versus normal corneas. The posterior elevation measurement in the 3-mm zone had the strongest power to distinguish keratoconus from normal. The corresponding figure for the 7-mm zone, however, had the strongest power to distinguish eyes with subclinical keratoconus (area under the curve, 0.98 and 0.92, respectively). Optimal cutoff point for posterior elevation in the 3-mm zone was 18.5 μm for keratoconus (sensitivity, 92%; specificity, 95%). The corresponding figure in the 7-mm zone was 50.5 μm for subclinical keratoconus (sensitivity, 79.9%; specificity, 94.0%).

Conclusions

Anterior and posterior elevations measured by the Galilei analyzer in the 3-mm zone can effectively discriminate keratoconus from normal corneas. These measurements in the 7-mm zone can be considered to distinguish subclinical keratoconus.