bluuebunny/crossref_metadata_2025 huggingface dataset:
A Dynamic Approach to Estimate Receiving Bandwidth for WebRTC
Authors: Iqbal Razib , Shirmohammadi Shervin , Atwah Rasha
Published: June 2016

Web Real-Time Communication (WebRTC), drafted by the World Wide Web Consortium (W3C) and Internet Engineering Task Force (IETF), enables direct browser-to-browser real-time communication. As its congestion control mechanism, WebRTC uses the Google Congestion Control (GCC) algorithm. But using GCC will limit WebRTC's performance in cases of overusing due to using a fixed decreasing factor, known as alpha (a). In this paper, the authors propose a dynamic alpha model to reduce the receiving bandwidth estimate during overuse as indicated by the overuse detector. Using their proposed model, the receiver can more efficiently estimate its receiving rate in case of overuse. They implemented their model over both unconstrained and constrained networks. Experimental results show noticeable improvements in terms of higher incoming rate, lower Round-Trip Time, and lower packet loss compared to the fixed alpha model.
SSIM-Based Distortion Estimation for Optimized Video Transmission over Inherently Noisy Channels
Authors: Sankisa Arun , Pandremmenou Katerina , Pahalawatta Peshala V. , Kondi Lisimachos P. , Katsaggelos Aggelos K.
Published: June 2016

The authors present two methods for examining video quality using the Structural Similarity (SSIM) index: Iterative Distortion Estimate (IDE) and Cumulative Distortion using SSIM (CDSSIM). In the first method, three types of slices are iteratively reconstructed frame-by-frame for three different combinations of packet loss and the resulting distortions are combined using their probabilities to give the total expected distortion. In the second method, a cumulative measure of the overall distortion is computed by summing the inter-frame propagation impact to all frames affected by a slice loss. Furthermore, the authors develop a No-Reference (NR) sparse regression framework for predicting the CDSSIM metric to circumvent the real-time computational complexity in streaming video applications. The two methods are evaluated in resource allocation and packet prioritization schemes and experimental results show improved performance and better end-user quality. The accuracy of the predicted CDSSIM values is studied using standard performance measures and a Quartile-Based Prioritization (QBP) scheme.
Effect of Heat Treatment on Microstructure and Tensile Properties of A356/V2O5 Insitu Composites
Authors: Singla Amneesh , Garg Rajnish , Saxena Mukesh
Published: June 2016

A 356 alloy reinforced with insitu V2O5 particles by using stir casting technique. The composites were produced by the addition of oxide particles in different weight percentage. The effect of oxide powder addition on microstructure and mechanical properties of produced composites were investigated. The effect of heat treatment on microstructure and mechanical properties were investigated by optical microscope, Microhardness tester and tension test. A significant improvement in hardness and tensile strength was revealed in the produced composite as compared to the base alloy. With the addition of oxide particles, the shape and size of eutectic Si changed which in turn affects the properties. It was observed that 2h solutionizing followed by the artificial aging was sufficient to make the structure homogenize and to produce the hardening precipitates. The improvement in the mechanical properties has been observed due to the age hardening precipitates in addition with refinement of insitu V2O5 particles.
Effect of Microstructure Degradation on Fracture Toughness of 20MnMoNi55 Steel in DBT Region
Authors: Bhowmik Sumit , Sahoo Prasanta , Acharyya Sanjib Kumar , Dhar Sankar , Chattopadhyay Jayanta
Published: June 2016

The paper considers the effect of microstructure degradation on fracture toughness of 20MnMoNi55 pressure vessel steel. This degradation is reflected through the shift of fracture toughness vs. temperature curve along the temperature axis and rise in reference temperature in ductile to brittle transition (DBT) region. Hardness also depends on the microstructure of metallic alloys. The present study explores the correlation between hardness and fracture toughness for different microstructures in order to calibrate loss in toughness from hardness. The master curve reference temperature and microhardness for different microstructures are measured experimentally. It is observed that there exists a fair linear relation between microhardness and reference temperature.
Improving In-Flight Learning in a Flapping Wing Micro Air Vehicle
Authors: Sam Monica , Boddhu Sanjay , Duncan Kayleigh , Botha Hermanus , Gallagher John
Published: June 2016

Much effort has gone into improving the performance of evolutionary algorithms that augment traditional control in a Flapping Wing Micro Air Vehicle. An EA applied to such a vehicle in flight is expected to evolve solutions quickly to prevent disruptions in following the desired flight trajectory. Time to evolve solutions therefore is a major criterion by which performance of an algorithm is evaluated. This paper presents results of applying an assortment of different evolutionary algorithms to the problem. This paper also presents some discussion on which choices for representation and algorithm parameters would be optimal for the flight control problem and the rationale behind it. The authors also present a guided sampling approach of the search space to make use of the redundancy of workable solutions found in the search space. This approach has been demonstrated to improve learning times when applied to the problem.
Risk Mitigation Practices in Banking
Authors: Baber Hasnan
Published: June 2016

The prime activity of a bank is to lend money and earn profits in the form of interest but by doing so the money is exposed to the risk of default where the borrower is not able to pay the money back in specified period or becomes insolvent. The research study carried out at HDFC Bank under the topic “Risk Mitigation practices in banking- a study of HDFC bank” to fulfill the said motive turned out to be useful in understanding the various policies and practices used by the bank to manage the different types of risk that arise in banking. The study is grounded on the both primary as well as secondary data. The purpose of the study was to examine the different practices followed by the bank to such type of risks and how these practices has helped the bank to decrease the effect of the risk on the profitability and operations . The study also coves the recent trends in the Non-Performing Asset levels of the bank and how bank has been successful in decreasing the pace of NPAs to minimize the burden of securitization.
Critical Analysis of the Role of the Reserve Bank of India in Managing Liquidity in the Interbank Market amidst Financial Stress
Authors: Das Rituparna
Published: June 2016

During the period 2011-12 of economic downturn characterized typically by economy wide loan defaults many banks in India are reported to have posted adequate levels of capital but experienced difficulties due to unsound liquidity management. In an attempt to examine the ease of liquidity management procedure of the Indian banking industry, this paper critically examines whether the central bank of the country facilitates liquidity management of the banks during the stress periods. The finding is that it does not.
Sustainable Development Initiatives and Strategies on Detrimental Effects of Mobile Phone
Authors: Velmurugan Manivannan Senthil
Published: June 2016

Mobile phones are universally popular due to their convenience. Mobile phones solve problems and offer new channels of communication by using a device small enough to fit into one hand. On the other hand, mobile phones are harmful to the environment and which leads to health problems in society and pollution problems via waste contamination and discharge of radiation. Concerns have recently been raised about the sustainability and potential effects on the environment of mobile phones. This study discusses the issues relating to risks associated with mobile phones and addresses sustainable development initiatives and strategies to rectify those issues.
Social Media
Authors: Kaur Manpreet , Verma Rajesh
Published: June 2016

Internet usage has shown drastic growth in the initial half of the year 2015 in India. The user base has increased over 354 million and with this India has become the top second country after China in terms of internet usage. Facebook is the prime social networking site which is used by 96% of urban users, followed by Google Plus (61%), Twitter (43%) and LinkedIn (24%). This extensive use of social media by the public had attracted the attention of the politicians to use it for election campaigns and has given researchers a reason to find out how politicians are engaging the public through this platform. Influence of Social media on the electorate has been proved from its successful use in the US presidential election in 2008 and by political parties in the 2014 Lok Sabha elections in India. This paper intends to explore the use of social media and its effectiveness in political elections through an extensive literature review. Social media has become an effective tool for political engagement and political participation as it is a low cost media as compared to traditional media. The low cost of this media has made it one of the main source to get information for advanced analysis and in-depth understanding of the electoral process. This paper will provide an insight to politicians, political analysts, journalists and electoral candidates regarding social media usage. The paper will also present a future research agenda to study how political parties can benefit from use of social media and change their strategies to engage workers and the voters.
Predicting Business Bankruptcy
Authors: Sarmento Rui , Trigo Luís , Fonseca Liliana
Published: June 2016

Managers, investors, financial institutions and government agencies have a major concern on forecasting enterprise bankruptcy. It enables the sustainability assessment of critical suppliers and clients, as well as competitors and the business environment. Throughout the 20th and the 21st century, advances in statistics and computer science fields enabled the development of different trends in financial distress assessment that co-exist today. However, recent Data Mining (DM) techniques are regarded as being the most precise. IT expertise requirements in the constantly evolving DM field may have been a major obstacle to the adoption of these techniques by decision makers. Furthermore, DM software tools that are now widespread offer a broad spectrum of Artificial Intelligence algorithms and the most difficult task may be the decision of selecting the appropriate algorithm. Hence, the adoption of a good workflow method for data processing and analysis is critical for having fast and reliable results. This work presents an overview of the available bankruptcy techniques and provides a comprehensive case study exploring the latest Data Mining techniques.
English Teachers' Practice and Perspectives on Using Educational Computer Games in EIL Context
Authors: Wang Li-Jen , Wu Ying-Tien , Hu Chiu-Ming
Published: June 2016

With in-depth interviews, the study explored 36 Taiwanese high school English teachers' practice and perspectives on using educational computer games (ECGs) in teaching English as an international language (EIL). The teachers were asked to experience an ECG for English vocabulary learning. Then, tape-recorded individual interviews were conducted. This study revealed that only few participant teachers had ever used computer games in their instruction; however, most of them were willing to use ECGs in their English classes in the future. It should be noticed that most participant teachers showed only poor understanding of ECGs and digital game-based learning.They recognized their insufficient specific pedagogical content knowledge (PCK), the need for technology-related skills, and the support from administration. Based on the finding derived from this study and those of previous research, cultural differences were further discussed. Also, implications for further research and teacher professional development were proposed.
An Extension to Simulated Web-Based Threats and Their Impact on Knowledge Communication Effectiveness
Authors: Chatelain-Jardon Ruth , Carmona Jesus S. , Kock Ned
Published: June 2016

This paper presents an extension to the study by Kock, Chatelain-Jardon, and Carmona (2008), An Experimental Study of Simulated Web-Based Threats and Their Impact on Knowledge Communication Effectiveness, and empirically validates their results. Kock and colleagues reported that enhanced memorization capacity can be used in computer interfaces to exploit knowledge communication. They evaluated the impact of an evolutionary adaptive web-simulated threat (simulated web-based snake attack) on the effectiveness of knowledge communication and reported positive and significant outcomes. This research extends their study by using a technology-related web-simulated threat and measuring its impact on knowledge communication effectiveness. This research showed that the subjects in the treatment condition performed approximately 34% better than those in the control condition, which, provides empirical support to the original study and shows how to exploit automatic brain mechanisms to enhance knowledge communication effectiveness throughout the design of computer interfaces.
Capturing local knowledge of beach seine fishers in the north-western province of Sri Lanka
Authors: Gunawardena Nuwan D. P. , Amarasinghe Upali S.
Published: June 2016

Local knowledge of fishers is considered to be useful in establishing effective dialogue between fishers and fishery managers to foster the sharing of power and responsibility between the government and local resource users. However, fishers’ local knowledge is often considered anecdotal and consequently, these knowledge bases are largely underutilized for small-scale fisheries management. This study was an attempt to investigate whether local knowledge of beach seine fishers of the north western province of Sri Lanka could be used to assist in optimizing their harvests, to scientifically validate anecdotal local knowledge and to recognize this knowledge base as an important means for defining fisheries co-management strategies.            The beach seine fishers in nine fishing communities use their local knowledge to predict the occurrence of fish schools based on some indicators such as sea surface colour due to the presence of fish schools, turbulence of surface water in the presence of schools of larger fish species and behaviour of sea birds. Fishers were also aware that local weather conditions influence the occurrence of certain fish species. Accordingly, fishers select the appropriate cod end type to catch predicted species. Spatial and temporal variations of species composition were found to be in accordance with the fishers’ local knowledge. Level of accuracy of fishers in all nine beach-seine fisher communities under the present study in selecting the appropriate cod end to be fixed to catch target species was high (64.9% - 82.9%). Psychometric approach adopted has shown that the mean harvest and mean daily income of fishing communities had significant positive correlations with fishers’ knowledge about management-related aspects. Results of this study have shown that fishers’ local knowledge is reasonably consistent and should therefore be incorporated for defining effective fisheries co-management.
Refractory Ascites with Liver Fibrosis Developed in Late Phase Allogeneic Hematopoietic Stem Cell Transplantation: Report of Three Patients
Authors: Hosoi Hiroki , Warigaya Kenji , Murata Shogo , Mushino Toshiki , Kuriyama Kodai , Nishikawa Akinori , Tamura Shinobu , Hatanaka Kazuo , Hanaoka Nobuyoshi , Muragaki Yasuteru , Murata Shinichi , Nakakuma Hideki , Sonoki Takashi
Published: June 2016

We report cases of three patients of refractory ascites without other fluid retention that occurred around five months after allogeneic hematopoietic stem cell transplantation (allo- HSCT). All three patients expired and postmortem examinations revealed unexpected liver fibrosis lacking histological evidences of graft-versus-host-disease (GVHD). The three patients showed normal hepatic function and size before transplantation. During their clinical courses, serum biochemistry test showed no elevation of hepatic enzymes and bilirubin; however, imaging studies demonstrated hepatic atrophy at the onset of ascites. One of the liver specimens showed bile obstruction, which could be seen in hepatic damage by GVHD. Although ascites resulting from venoocclusive disease in early phase allo-HSCT is well documented, ascites associated with hepatic fibrosis in late phase allo-HCST has not been reported. Further clinico-pathological studies on similar patients should be required to ascertain refractory ascites associated with liver fibrosis after allo-HSCT.
Massive pulmonary embolism at the onset of acute promyelocytic leukemia
Authors: Sorà Federica , Chiusolo Patrizia , Laurenti Luca
Published: June 2016

Life-threatening bleeding is a major and early complication of acute promyelocytic leukemia (APL), but in the last years there is a growing evidence of thromboses in  APL. We report the first case of a young woman with dyspnea as the first symptom of APL due to massive pulmonary embolism (PE) successfully treated with thrombolysis for PE and heparin. APL has been processed with a combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) obtaining complete remission.
MOLECULAR HETEROGENEITY OF GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY IN BURKINA FASO: G-6-PD BETICA SELMA AND SANTAMARIA IN PEOPLE WITH SYMPTOMATIC MALARIA IN OUAGADOUGOU
Authors: OUATTARA Abdoul Karim , YAMEOGO Pouiré , DIARRA Birama , OBIRI-YEBOAH Dorcas , YONLI Albert Theophane , COMPAORE Tegwindé Rebeca , SOUBEIGA Serge Théophile , DJIGMA Florencia Wenkuuni , Simpore Jacques
Published: June 2016

The G-6-PD deficiency has an important polymorphism with genotypic variants such as 202A/376G, 376G/542T and 376G/968T known in West African populations. It would confer protection against severe forms of malaria although there are differences between the various associations in different studies. In this study we genotyped six (06) variants of the G-6-PD gene in people with symptomatic malaria in urban areas in Burkina Faso.One hundred and eighty-two (182) patients who tested positive using rapid detection test and microscopy were included in this study. A regular PCR with the GENESPARK G6PD African kit was run followed by electrophoresis, allowing initially to genotype six SNPs (G202A, A376G, A542T, G680T, C563T and T968C). Women carrying the mutations 202A and/or 376G were further typed by real-time PCR using TaqMan probes rs1050828 and rs1050829.In the study population the G-6-PD deficiency prevalence was 9.9%. In addition of G-6-PD A- (202A/376G) variants, 376G/542Tand 376G/968T were detected. Hemoglobin electrophoresis revealed that 22.5% (41/182) of the individuals had HbAC compared with 2.2% with HbAS and one individual had double heterozygous HbSC. There was no correlation between the G-6-PD deficiency or haemoglobinopathies and symptomatic malaria in this study.As opposed to previous genotyping studies carried out in Burkina Faso, this study shows for the first time the presence of the variant A- (376G/968C) and warrants further investigation at the national level and in specific ethnic groups.
EPIDEMIOLOGY OF CARBAPENEM RESISTANT KLEBSIELLA PNEUMONIAE INFECTIONS IN MEDITERRANEAN COUNTRIES
Authors: Girmenia Corrado , Canichella Martina , Serrao Alessandra
Published: June 2016

Infections by Carbapenem-Resistant Enterobacteriaceae (CRE), in particular carbapenem-resistant Klebsiella pneumoniae (CRKp), are a significant public health challenge worldwide. Resistance to carbapenems in enterobacteriaceae is linked to different mechanisms, in particular the production of different types of enzymes including KPC, VIM, IMP, NDM, and OXA-48. Despite several attempts to control the spread of these infections at local and national level, epidemiological situation for CRKp had worsened in the last years in the Mediterranean area. The rate and types of CRKp isolates greatly differ in the various Mediterranean countries. KPC-producing K.pneumoniae is diffused particularly in the European countries bordering the Mediterranean sea and is actually endemic in Greece and Italy. On the contrary, OXA-48-producing K.pneumoniae is endemic in Turkey and Malta, and diffused at inter-regional level particularly in some north African and Middle East countries. The spread of these multiresistant pathogens in the world and the Mediterranean countries has been related to various epidemiological factors including the international transfer of patients coming from endemic areas.
An Integrated Approach for RNA-seq Data Normalization
Authors: Yang Shengping , Mercante Donald E. , Zhang Kun , Fang Zhide
Published: June 2016

Background

DNA copy number alteration is common in many cancers. Studies have shown that insertion or deletion of DNA sequences can directly alter gene expression, and significant correlation exists between DNA copy number and gene expression. Data normalization is a critical step in the analysis of gene expression generated by RNA-seq technology. Successful normalization reduces/removes unwanted nonbiological variations in the data, while keeping meaningful information intact. However, as far as we know, no attempt has been made to adjust for the variation due to DNA copy number changes in RNA-seq data normalization.

Results

In this article, we propose an integrated approach for RNA-seq data normalization. Comparisons show that the proposed normalization can improve power for downstream differentially expressed gene detection and generate more biologically meaningful results in gene profiling. In addition, our findings show that due to the effects of copy number changes, some housekeeping genes are not always suitable internal controls for studying gene expression.

Conclusions

Using information from DNA copy number, integrated approach is successful in reducing noises due to both biological and nonbiological causes in RNA-seq data, thus increasing the accuracy of gene profiling.
Subclinical LV Dysfunction Detection Using Speckle Tracking Echocardiography in Hypertensive Patients with Preserved LV Ejection Fraction
Authors: Ayoub Amal Mohamed , Keddeas Viola William , Ali Yasmin Abdelrazek , Okl Reham Atef El
Published: June 2016

Background

Early detection of subclinical left ventricular (LV) systolic dysfunction in hypertensive patients is important for the prevention of progression of hypertensive heart disease.

Methods

We studied 60 hypertensive patients (age ranged from 21 to 49 years, the duration of hypertension ranged from 1 to 18 years) and 30 healthy controls, all had preserved left ventricular ejection fraction (LVEF), detected by two-dimensional speckle tracking echocardiography (2D-STE).

Results

There was no significant difference between the two groups regarding ejection fraction (EF) by Simpson's method. Systolic velocity was significantly higher in the control group, and global longitudinal strain was significantly higher in the control group compared with the hypertensive group. In the hypertensive group, 23 of 60 patients had less negative global longitudinal strain than −19.1, defined as reduced systolic function, which is detected by 2D-STE (subclinical systolic dysfunction), when compared with 3 of 30 control subjects.

Conclusion

2D-STE detected substantial impairment of LV systolic function in hypertensive patients with preserved LVEF, which identifies higher risk subgroups for earlier medical intervention.
The Effects of the UK Pregnancies Better Eating and Activity Trial Intervention on Dietary Patterns in Obese Pregnant Women Participating in a Pilot Randomized Controlled Trial
Authors: Flynn Angela C. , Schneeberger Caroline , Seed Paul T. , Barr Suzanne , Poston Lucilla , Goff Louise M.
Published: June 2016

Objective

The objective of this study is to investigate the effects of the UK Pregnancies Better Eating and Activity Trial (UPBEAT) behavioral intervention on dietary patterns in obese pregnant women.

Methods

Dietary patterns were derived from Food Frequency Questionnaires using principal component analysis in 183 UPBEAT pilot study participants.

Results

Two unhealthy dietary patterns, processed and traditional, predominantly characterized by foods high in sugar and fat, improved [processed -0.54 (-0.92 to -0.16), P = 0.006 and traditional -0.83 (-1.20 to -0.45), P < 0.001] following the intervention, while a cultural pattern that was found to be associated with the Black African/Caribbean participants did not change [-0.10 (-0.46 to 0.26), P = 0.589].

Conclusion

Unhealthy dietary patterns are evident in obese pregnant women. The UPBEAT intervention was effective in improving maternal dietary patterns; however, obese pregnant women from minority ethnic groups may be less receptive to intervention.
Computational Geometric and Algebraic Topology
Authors: Burton Benjamin , Edelsbrunner Herbert , Erickson Jeff , Tillmann Stephan
Published: June 2016

Computational topology is a young, emerging field of mathematics that seeks out practical algorithmic methods for solving complex and fundamental problems in geometry and topology. It draws on a wide variety of techniques from across pure mathematics (including topology, differential geometry, combinatorics, algebra, and discrete geometry), as well as applied mathematics and theoretical computer science. In turn, solutions to these problems have a wide-ranging impact: already they have enabled significant progress in the core area of geometric topology, introduced new methods in applied mathematics, and yielded new insights into the role that topology has to play in fundamental problems surrounding computational complexity.

At least three significant branches have emerged in computational topology: algorithmic 3-manifold and knot theory, persistent homology and surfaces and graph embeddings. These branches have emerged largely independently. However, it is clear that they have much to offer each other. The goal of this workshop was to be the
first significant step to bring these three areas together
, to share ideas in depth, and to pool our expertise in approaching some of the major open problems in the field.
History of Mathematics: Models and Visualization in the Mathematical and Physical Sciences
Authors: Gray Jeremy J. , Hashagen Ulf , Hoff Kjeldsen Tinne , Rowe David E.
Published: June 2016

This workshop brought together historians of mathematics and science as well as mathematicians to explore important historical developments connected with models and visual elements in the mathematical and physical sciences. It addressed the larger question of what has been meant by a model, a notion that has seldom been subjected to careful historical study. Most of the talks dealt with case studies from the period 1800 to 1950 that covered a number of analytical, geometrical, mechanical, astronomical, and physical phenomena. The workshop also considered the role of visual thinking as a component of mathematical creativity and understanding.
О представлении решений задачи о движении тяжелого твердого тела в случае Ковалевской в $\zeta$- и $\wp$-функциях Вейерштрасса и неинтегрируемости в квадратурах случая Гесса
Authors: Belyaev Alexandr Vladimirovich
Published: June 2016

Предложен способ представления решений Делоне и некоторых других частных решений задачи о движении тяжелого твердого тела в случае Ковалевской в $\zeta$- и $\wp$-функциях Вейерштрасса. Для случая Гесса задачи о движении тяжелого твердого тела доказана невозможность решения в квадратурах.
Библиография: 24 названия.
Neutral atmosphere temperature trends and variability at 90 km, 70 °N, 19 °E, 2003–2014
Authors: Holmen Silje Eriksen , Hall Chris M. , Tsutsumi Masaki
Published: June 2016

Abstract. Neutral temperatures at 90 km height above Tromsø, Norway, have been determined using ambipolar diffusion coefficients calculated from meteor echo fading times using the Nippon/Norway Tromsø Meteor Radar (NTMR). Daily temperature averages have been calculated from November 2003 to October 2014 and calibrated against temperature measurements from the Microwave Limb Sounder (MLS) on board Aura. Large-scale periodic oscillations ranging from ∼ 9 days to a year were found in the data using Lomb–Scargle periodogram analysis, and these components were used to seasonally detrend the daily temperature values before assessing trends. Harmonic oscillations found are associated with the large-scale circulation in the middle atmosphere together with planetary and gravity wave activity. The overall temperature change from 2003 to 2014 is −2.2 K ± 1.0 K decade−1, while in summer (May–June–July) and winter (November–December–January) the change is −0.3 K ± 3.1 K decade−1 and −11.6 K ± 4.1 K decade−1, respectively. The temperature record is at this point too short for incorporating a response to solar variability in the trend. How well suited a meteor radar is for estimating neutral temperatures at 90 km using meteor trail echoes is discussed, and physical explanations behind a cooling trend are proposed.
The regional impact of urban emissions on climate over central Europe: present and future emission perspective
Authors: Huszár Peter , Belda Michal , Karlický Jan , Pišoft Petr , Halenka Tomáš
Published: June 2016

Abstract. The regional climate model RegCM4.2 was coupled to the chemistry transport model CAMx, including two-way interactions, to evaluate the regional impact of urban emission from Central European cities on climate for present (2001–2010) and future (2046–2055). Short-lived non-CO2 emissions are considered, and, for the future impact, only the emission changes are accounted for (the climate is kept 'fixed'). The urban impact on climate is calculated with the annihilation approach, when two experiments are performed: one with all emissions included and one without considering urban emissions. The radiative impacts of non-CO2 primary and secondary formed pollutants are considered: namely ozone (O3), sulfates (PSO4), nitrates (PNO3), primary organic and elementary carbon (POA and PEC). The validation of the modeling system is limited to key climate parameters, near surface and precipitation. It shows that the model, in general, under-estimates temperature and overestimates precipitation. We attribute this behavior to too much cloudiness/water vapor present in the model atmosphere as a consequence of over-predicted evaporation from the surface. The impact on climate is characterized by a statistically significant cooling up to −0.02 K and −0.04 K in winter (DJF) and summer (JJA) season, mainly over cities. We found that the main contributor to the cooling is the aerosols direct and indirect effects, while the ozone titration, calculated especially for DJF, plays rather a minor role. In accordance with the vertical extent of the urban emission induced aerosol perturbation, cooling dominates the first few model layers up to about 150 m in DJF and 1000 m in JJA. We found a clear diurnal cycle of the radiative impacts with maximum cooling just after noon (JJA) or later in afternoon (DJF). Furthermore, statistically significant decreases of surface radiation are modeled, in accordance with the temperature decrease. The impact on the boundary later height is small but statistically significant and reaches −1 m and −6 m decreases in DJF and JJA, respectively. We did not find any statistically significant impact on precipitation and wind speed. Considering future emissions, the impacts are, in general, smaller – as a consequence of smaller emissions resulting in smaller urban induced chemical perturbations. In overall, the study suggest that the non-CO2 emissions play rather a minor role in modulating regional climate over central Europe. Much more important is the direct climate impact of urban surfaces trough urban canopy meteorological effects as we showed earlier.
Multidecadal Variations of the Effects of the Quasi-Biennial Oscillation on the Climate System
Authors: Brönnimann Stefan , Malik Abdul , Stickler Alexander , Wegmann Martin , Raible Christoph C. , Muthers Stefan , Anet Julien , Rozanov Eugene , Schmutz Werner
Published: June 2016

Abstract. Effects of the Quasi-Biennial Oscillation (QBO) on tropospheric climate are relatively small or appear only intermittently. Studying them requires long time series of both the QBO and climate variables, which has restricted previous studies to the past 30–50 years. Here we use the benefits of an existing QBO reconstruction back to 1908. We first investigate additional, newly digitized historical observations of stratospheric winds to test the reconstruction. Then we use the QBO time series to analyze atmospheric data sets (reconstructions and reanalyses) as well as the results of coupled ocean-atmosphere-chemistry climate model simulations that were forced with the reconstructed QBO. We investigate effects related to (1) tropical-extratropical interaction in the stratosphere, wave-mean flow interaction, and subsequent downward propagation and (2) interaction between deep tropical convection and stratospheric flow. We generally find weak connections, though some are statistically significant over the 100-year period and consistent with model results. Apparent multidecadal variations in the connection between the QBO and the investigated climate responses are consistent with a small effect in the presence of large variability, with one exception: the imprint on the northern polar vortex, which is seen in recent reanalysis data, is not found in the period 1908–1957. Conversely, an imprint in Berlin surface air temperature is only found in 1908–1957, but not in the recent period. In the model simulations, likewise, both links tend to appear alternatingly, suggesting a more systematic modulation. Over the Pacific warm pool, we find increased convection during easterly QBO mainly in boreal winter in observation-based data as well as in the model simulations, with large variability. No QBO effects were found in the Indian monsoon strength or Atlantic hurricane frequency.
The influence of episodic flooding on pelagic ecosystem in the East China Sea
Authors: Chen Chung-Chi , Gong Gwo-Ching , Chou Wen-Chen , Chung Chih-Ching , Hsieh Chih-Hao , Shiah Fuh-Kwo , Chiang Kuo-Ping
Published: June 2016

Abstract. This study was designed to determine the effects of flooding on pelagic ecosystem in the East China Sea (ECS), especially on plankton community respiration (CR). In July 2010, a flood occurred in the Changjiang River. As a comparison, a variety of both abiotic and biotic parameters were monitored, as well as in July 2009, a non-flooding period. During the flooding, the Changjiang diluted water (CDW) zone covered almost two thirds of the ECS, which was approximately six times that of the non-flooding period. The mean nitrate concentration was higher in 2010 (6.2 μM) than in 2009 (2.0 μM). However, during the 2010 flood, the mean values of Chl a and bacterial biomass were only slightly higher or even lower than in 2009. However, the CR was still higher in 2010 than in 2009, with mean values of 105.6 and 73.2 mg C m−3 d−1, respectively. The higher CR in 2010 could be attributed to vigorous plankton metabolic activities, especially phytoplankton, at stations in the CDW zone, which were not characterized by low SSS in 2009. In addition, zooplankton might be another important component contributing to the high CR rate observed in 2010. Furthermore, there was a significant amount of fCO2 drawdown in the 2010 flood. These results suggest that the flood in 2010 had a significant effect on the carbon balance in the ECS. This effect might become more pronounced in the future, as extreme rainfall events and flooding magnitudes are predicted to increase globally due to climate change.
How sensitive are modeled contemporary subsea permafrost thaw and thickness of the methane clathrates stability zone in Eurasian Arctic to assumptions on Pleistocene glacial cycles?
Authors: Malakhova Valentina V. , Eliseev Alexey V.
Published: June 2016

Abstract. Single-point simulations with a model for thermal state of subsea sediments driven by the forcing constructed from the ice core data show that the impact of initial conditions is lost after ~ 100 kyr. The time scales of temperature propagation in sediments and respective permafrost response are ~ 10–20 kyr which is longer than the present interglacial. The timings of shelf exposure during oceanic regressions and flooding during transgressions are important for representation of sediment thermal state and hydrates stability zone (HSZ). These timings should depend on the contemporary shelf depth (SD). During glacial cycles temperature at the top of sediments is a major driver of HSZ vertical boundaries change for SD of few tens of meters, while the pressure exerted by oceanic water becomes more important for larger SD. Thus, even the existence of HSZ and its disappearance might not be easily tied to oceanic transgressions and regressions.
Seabirds as samplers of the marine environment – a case study in Northern Gannets
Authors: Garthe Stefan , Peschko Verena , Kubetzki Ulrike , Corman Anna-Marie
Published: June 2016

Abstract. Understanding distribution patterns, activities, and foraging behaviours of seabirds requires interdisciplinary approaches. In this paper, we provide examples of the data and analytical procedures from a new study in the German Bight, North Sea, tracking Northern Gannets (Morus bassanus) at their breeding colony on the island of Helgoland. Individual adult Northern Gannets were equipped with different types of data loggers for several weeks, measuring geographic positions and other parameters mostly at 3–5 min intervals. Birds flew in all directions from the island to search for food, but most flights targeted areas to the (N)NW of Helgoland. Foraging trips were remarkably variable in duration and distance; most trips lasted 1–15 h and extended from 3–80 km from the breeding colony on Helgoland. Dives of gannets were generally shallow, with more than half of the dives only reaching depths of 1–3 m. The maximum dive depth was 11.4 m. Gannets showed a clear diurnal rhythm in their diving activity, with dives being almost completely restricted to the daylight period. Most flight activity at sea occurred at an altitude between the sea surface and 40 m. Gannets mostly stayed away from the wind farms and passed around them much more frequently than flying through them. Detailed information on individual animals may provide important insights into various processes, based on multi-layer information.
Quality assessment of the TOPAZ4 reanalysis in the Arctic over the period 1991–2013
Authors: Xie Jiping , Bertino Laurent , Counillon Francois , Lisæter Knut A. , Sakov Pavel
Published: June 2016

Abstract. Long dynamical atmospheric reanalyses are widely used for climate studies, but data assimilative reanalyses of the Arctic ocean and sea ice are less common. TOPAZ4 is a coupled ocean and sea ice data assimilation system for the North Atlantic and the Arctic that is based on the HYCOM ocean model and the Ensemble Kalman Filter data assimilation method using 100 dynamical members. A 23-years reanalysis has been completed for the period 1991–2013. This study presents its quantitative quality assessment, compared to both assimilated and unassimilated observations available in the whole Arctic region in order to document the strengths and weaknesses of the system for potential users. It is found that TOPAZ4 performs well with respect to near surface ocean variables, but some limitations appear in the interior of the ocean and for ice thickness, where observations are sparse. In the course of the reanalysis, the skills of the system are improving as the observation network becomes denser, in particular during the International Polar Year. The online bias estimation successfully maintains a low bias in our system.
Defining a Mid-Holocene earthquake through speleoseismological and independent data: constraints for the outer Central Apennines (Italy) seismotectonic framework
Authors: Di Domenica Alessandra , Pizzi Alberto
Published: June 2016

Abstract. A speleoseismological study has been conducted in the Cavallone Cave, located in the easternmost carbonate sector of the Central Apennines (Maiella Massif), in a seismically active region interposed between the post-orogenic extensional domain, to the west, and the compressional one, to the east. The occurrence of active ''silent normal faults'', to the west, close to blind thrust, to the east, raises critical questions about the identification of the true seismogenic sources for this transitional zone. Large ceiling collapses, fractures, broken speleothems with new re-growing stalagmites on their top, preferential orientation of fallen stalagmites and absence of thin and long concretions have been observed in many portions of the conduit and may indicate that the cave suffered of sudden and catastrophic events likely linked to the occurrence of past strong earthquakes. Although controversies exist about the correlation between speleotectonic observations and quantitative modeling, speleotectonic studies, when corroborated by independent data collected outside caves, can play a fundamental role in discovering past earthquakes. Radiocarbon dating and, above all, the surprisingly correspondence with other coeval paleoseismological and geological data collected in surrounding areas outside the cave, provide important constraints for the individuation of a Mid-Holocene paleoearthquake around 4770 ± 30 yr BP and for the identification of the Sulmona normal fault as the most likely causative structure.
Fully probabilistic seismic source inversion – Part 2: Modelling errors and station covariances
Authors: Stähler Simon C. , Sigloch Karin
Published: June 2016

Abstract. Seismic source inversion, a central task in seismology, is concerned with the estimation of earthquake source parameters and their uncertainties. Estimating uncertainties is particularly challenging because source inversion is a non-linear problem. In a companion paper, Stähler & Sigloch (2014) developed a method of fully Bayesian inference for source parameters, based on measurements of waveform cross-correlation between broadband, teleseismic body-wave observations and their modeled counterparts. This approach yields not only depth and moment tensor estimates but also source time functions. A prerequisite for Bayesian inference is the proper characterization of the noise distribution afflicting the measurements, a problem we address here. We show that for realistic broadband body-wave seismograms, the systematic error due to an incomplete physical model affects waveform misfits more strongly than random, ambient background noise. In this situation, the waveform cross-correlation coefficient CC or rather its decorrelation D = 1 − CC, performs more robustly as a misfit criterion than LP-norms, more commonly used measures of misfit based on distances between individual time samples. From a set of over 900 user-supervised, deterministic source solutions treated as a quality-controlled reference, we derive the noise distribution on signal decorrelation D = 1 − CC of the broadband seismogram fits. The noise on D is found to approximately follow a log-normal distribution, a fortunate fact that readily accommodates the formulation of a likelihood function for D for our multivariate problem. The first and second moments of this multivariate distribution are shown to depend mostly on the signal-to-noise ratio of the CC measurements and on the back-azimuthal distances of seismic stations. By identifying and quantifying its likelihood function, we make D and thus waveform cross-correlation measurements usable for fully probabilistic sampling strategies, in source inversion and related applications such as seismic tomography.
A multi-stage 3D stress field modelling approach exemplified in the Bavarian Molasse Basin
Authors: Ziegler Moritz O. , Heidbach Oliver , Reinecker John , Przybycin Anna M. , Scheck-Wenderoth Magdalena
Published: June 2016

Abstract. The knowledge of the contemporary in-situ stress state is a key issue for a safe and sustainable subsurface engineering. However, information on the orientation and magnitudes of the stress state are few and often not available in the areas of interest. Therefore 3D geomechanical numerical modelling is used to estimate the in-situ stress state and the distance of faults from failure for application in subsurface engineering. The main challenge in this approach is to bridge the gap in scales between the widely scattered data used for calibration of the model and the high resolution in the target area required for the application. We present a multi-stage 3D geomechanical numerical approach which provides a state of the art model of the stress field for a reservoir scale area from widely scattered data records. Therefore we first use a large scale regional model which is calibrated by available stress data and provides the full 3D stress tensor at discrete points in the entire model volume. The modelled stress state is used subsequently for the calibration of a smaller scale model located within the large scale model in an area without any observed stress data records. We exemplify this approach with two-stages for the area around Munich in the German Molasse Basin. We estimate the scalar values for slip tendency and fracture potential as measures for the criticality of fault reactivation in the reservoir scale model. Furthermore, the modelling results show that variations due to uncertainties in the input data are mainly introduced by the uncertain material properties and missing SHmax magnitude data. This leads to the conclusion that at this stage the model’s reliability depends only on the amount and quality of available input data rather than on the modelling technique itself. Any improvements of modelling and increases in model reliability can only be achieved by more high-quality data for calibration.
Khartoum Goliath: SPLM/SPLA Update and Martial Theology during the Second Sudanese Civil War
Authors: Tounsel Christopher
Published: June 2016

During the Second Sudanese Civil War, the Sudan People's Liberation Movement/Army published a weekly newspaper entitled SPLA/SPLM Update. This article builds on previous scholarship about the role of Christianity in the Sudanese civil conflict by revealing how the SPLM/SPLA Update was an essential medium of the conflict and contributed to its framing in religious terms. The Update published content that constituted a martial theology pitting the SPLA against the National Islamic Front, the party of the Muslim Brothers under Hassan Turabi's leadership. It interpreted events using biblical and ancient Israelite templates, placed circumstances in a narrative trajectory, and transformed political history into a spiritual chronicle. In so doing, it attracted readers beyond the geographic borders of Sudan, situating Christian Sudan in a contemporary global Sudanese diaspora while also reaching into the ancient past to locate the contemporary struggles of Sudanese Christians in an older story of divine chosenness.