bluuebunny/crossref_metadata_2025 huggingface dataset:
Big Data Analytics Platforms for Electric Vehicle Integration in Transport Oriented Smart Cities
Authors: Hussain Md Muzakkir , Beg M.M. Sufyan , Alam Mohammad Saad , Laskar Shahedul Haque
Published: April 2019

Electric vehicles (EVs) are key players for transport oriented smart cities (TOSC) powered by smart grids (SG) because they help those cities to become greener by reducing vehicle emissions and carbon footprint. In this article, the authors analyze different use-cases to show how big data analytics (BDA) can play vital role for successful electric vehicle (EV) to smart grid (SG) integration. Followed by this, this article presents an edge computing model and highlights the advantages of employing such distributed edge paradigms towards satisfying the store, compute and networking (SCN) requirements of smart EV applications in TOSCs. This article also highlights the distinguishing features of the edge paradigm, towards supporting BDA activities in EV to SG integration in TOSCs. Finally, the authors provide a detailed overview of opportunities, trends, and challenges of both these computing techniques. In particular, this article discusses the deployment challenges and state-of-the-art solutions in edge privacy and edge forensics.
A Cloud-Based Smartphone Solution for Transmitting Bio-Signals From an Emergency Response Vehicle
Authors: Mukhopadhyay Adwitiya , Sreekumar Sidharth , Xavier Bobin , Suraj M
Published: April 2019

Most developing countries are currently unable to provide adequate, let alone advanced healthcare support to rural areas. Telemedicine combines the capability of information technology and dedicated people working towards the common goal of providing good quality healthcare in remote areas. In this article, the authors propose a system that can be used to transmit patient vitals like pulse rate, oxygen saturation, and perfusion index readings to a doctor in a remote area, while a patient is in transit. This system uses a smartphone application, a pulse oximeter, and the real-time data transferring capabilities of Firebase (a cloud database). The application has been tested under various network conditions which includes connection types such as 2G (2nd Generation), 3G (3rd Generation), 4G (4th Generation), and Fiber To The Home (FTTH). The work also discusses the possible reasons for the higher performance found in 4G networks over 3G and 2G cellular connections.
Diagnostic Assessment Techniques and Non-Invasive Biomarkers for Autism Spectrum Disorder
Authors: Tanu  , Kakkar Deepti
Published: April 2019

Autism spectrum disorder (ASD) is a complex heterogeneous neurological disorder that has led to a spectrum of diagnosis techniques. The screening instruments, medical and technological tools initiate the diagnosis process. Clinicians and psychologists propose therapies depending on the examination done by these methodologies. The literature has accounted dozens of diagnostic methods and alternative and complementary therapies but still lack in highlighting the proper biomarker for early detection and intervention. The emerging multi-modal neuro-imaging techniques have correlated the brain's functional and structural measures and diagnosed ASD with more sensitivity than individual approaches. The purpose of this review article is: (i) to provide an overview of the emerging ASD diagnosis methods and different markers and; (ii) to present the idea of integrating all the individual methods in to a multi-modal diagnostic system to enhance detection sensitivity. This system possesses the potential to diagnose and predict ASD clinically, neurologically & objectively with high detection sensitivity.
Pragmatism in Decision Support System Research
Authors: Rahman Mohammad Tafiqur
Published: April 2019

Decision making on relief distribution is a complex multidisciplinary task in humanitarian logistics. It incorporates decision makers from different but related problem areas. The failure to perform assigned decision-making tasks in any area makes the entire system unstable and delays the relief distribution process. An organized, well-planned, and practical decision support system (DSS) can assist practitioners in making rapid decisions on delivering relief items. Hence, DSS researchers in humanitarian logistics require rigorous thinking, close and critical analysis, and the identification of challenges to conduct research or validate the generated knowledge properly. To perform such complex knowledge-based tasks, the philosophical understanding of DSS in the humanitarian context is necessary. After analyzing the commonly used philosophical paradigms, this research identifies the pragmatic approach as the adequate support for solving decision-making problems in relief distribution during large-scale disasters.
Enhanced Event Detection in Twitter Through Feature Analysis
Authors: Dharini Ramachandran.  , Parvathi R.
Published: April 2019

The Digital era has the benefits in unearthing a large amount of imperative material. One such digital document is social media data, which when processed can give rise to information which can be helpful to our society. One of the many things that we can unearth from social media is events. Twitter is a very popular microblog that encompasses fruitful and rich information on real world events and popular topics. Event detection in view of situational awareness for crisis response is an important need of the current world. The identification of tweets comprising information that may assist in help and rescue operation is crucial. Most pertinent features for this process of identification are studied and the inferences are given in this article. The efficiency and practicality of the features are discussed here. This article also presents the results of experimentation carried out to assess the most relevant combination of features for improved performance in event detection from Twitter.
Enhancing In-Service Primary Teachers' Technological, Pedagogical and Content Knowledge on Mobile Mathematics Learning
Authors: Tsouccas Loucas Fl. , Meletiou-Mavrotheris Maria
Published: April 2019

This article reports on the main insights from a study aimed at equipping a group of in-service teachers with the knowledge, skills, and practical experience required to effectively integrate tablet devices within the mathematics curriculum. A professional development program focused on mobile mathematics learning and based on the Technological Pedagogical and Content Knowledge (TPACK) framework was designed and implemented in Cyprus. Six primary school teachers participated in the program. Participants experimented with different ways in which coding apps, and other types of constructivist mobile applications could help students internalize key mathematical concepts across the primary curriculum. They also worked together to develop and/or deliver instructional interventions integrating the use of mobile devices. Findings indicate a positive impact on in-service teachers' perceptions regarding mobile-enhanced mathematics, and on their competence in productively utilizing mobile apps as an instructional tool.
A Meta-Analysis on the Effects of Learning with Robots in Early Childhood Education in Korea
Authors: Park Sung-Deok , Kim Eun-Jung , Kim Kyung-Chul
Published: April 2019

This meta-analysis examines the effects of learning with robots (r-learning) on young children and, on this basis, gives suggestions for using robotics in education for young children. A test of homogeneity was performed for 27 Korean studies done between 2008 and 2016 and a random effect model introduced to reveal the effect sizes. The overall effect size was medium to large at 0.72. After analyzing gaps in effect sizes with different categorical moderator variables, the authors found significant differences depending on platform type, activity type, dependent variables for r-learning effect, and age. The study also investigates relationships between effect size and continuous moderator variables such as treatment period and year of publication. The meta-regression model showed a significantly negative relationship between effect size and year of publication. Thus, effects of r-learning on a young child are generally beneficial, and r-learning also improves variables like a child's social nature, though conversely the effect on language development appears below average.
Violence, Emotionally Abusive and Controlling Behaviour in Intimate Partner Relationships
Authors: Kurebwa Jeffrey
Published: April 2019

This study focused on intimate partner violence (IPV) in relationships in the Bindura urban of Zimbabwe. IPV exert a long-term influence in relationships. One of the most dangerous forms of violence is performed by an intimate partner. People in relationships experience all forms of IPV such as physical, emotional, economic, and sexual. Violence is often perpetrated against an intimate partner as a way of showing systematic patterns of dominance and control. Qualitative methodology was used in this study. Data was collected through key informant interviews, focus group discussions and documentary sources. The research concludes that intimate partner violence impacts survivors' immediate sexual, physical and psychological health and increases the risks of longer-term health problems and social stigma.
Effects on Current Day Technology, Legislation with Respect to Ethical Valuation
Authors: Galli Brian J.
Published: April 2019

Edward Snowden is an American who released classified government information to journalists in June 2013. These secrets revealed the existence and purpose of numerous government mass-surveillance programs, which were developed to gather, retain, and analyze electronic information not only on a nationwide scale but also on a global scale. Due to his actions, some would describe Snowden as a villain or traitor, while others would describe him as a hero or patriot. After the release of information about large government surveillance programs, there are varied opinions as to whether this had a reforming effect on our society from a technical and legislative standpoint. However, there has been very little focus on whether the absence or presence of these changes has any correlation or effect on what we think about it ethically. This research is intended to discuss if the results of Edward Snowden's actions had an impact on cybertechnology and legislation due to the ethical considerations surrounding it.
Plasma Sprayed WC-12%Co-Coatings for TBC Applications on Diesel Engine Piston
Authors: Das Debasish , Verma Rajeev , Pathak Vipul
Published: April 2019

In the present study, plasma sprayed WC-12%Co coatings with 100µm NiCrAlY bond coat on a substrate of A336 cast aluminum alloy have been investigated for a thermal barrier coating (TBC) application. The coatings deposited with varying topcoat thickness up to 500µm were deposited on the piston top surface of an Indian hatchback diesel car to act as a thermal barrier and enhance the thermal efficiency of the engine. Although all the specimens with distinct coating overlays survived 350 thermal cycles, the one with 200µm thickness exhibited the best thermal shock behavior as they exuded the most cycles to surface cracks initiation. Moreover, SEM analysis also suggested 200 µm thick coating to be optimal for thermal shock behavior in diesel engine components. The coating phase analysis by XRD and the lattice strain analysis performed by a Williamson-Hall (W-H) analysis did not reveal any structural changes after the thermal shock experiment.
Unobtrusive Academic Emotion Recognition Based on Facial Expression Using RGB-D Camera Using Adaptive-Network-Based Fuzzy Inference System (ANFIS)
Authors: Purnama James , Sari Riri Fitri
Published: April 2019

Quality of learning in the classroom is influenced by many factors. One of them is the academic emotions of the students. The emotion detection in the classroom cannot be done by using sensors attached to the body of the students, because it would disturb the concentration of the students. The proposed solution is by using unobtrusive emotion detection, e.g. by placing video capture equipment, which is not visible at the front of the student's desk. In this study, an RGB - Depth Microsoft Kinect camera is used to record facial expressions by considering the convenience factor of the students, speed of response time, and cost efficiency. A combination of Cohn-Kanade dataset and EURECOM dataset is used as the training set in machine learning with Adaptive-Network-Based Fuzzy Inference System (ANFIS) algorithm, with 8 sample of Asian race students (4 male and 4 female students).
Test Suite Optimization Using Firefly and Genetic Algorithm
Authors: Pandey Abhishek , Banerjee Soumya
Published: April 2019

Software testing is essential for providing error-free software. It is a well-known fact that software testing is responsible for at least 50% of the total development cost. Therefore, it is necessary to automate and optimize the testing processes. Search-based software engineering is a discipline mainly focussed on automation and optimization of various software engineering processes including software testing. In this article, a novel approach of hybrid firefly and a genetic algorithm is applied for test data generation and selection in regression testing environment. A case study is used along with an empirical evaluation for the proposed approach. Results show that the hybrid approach performs well on various parameters that have been selected in the experiments.
Using Vehicles as Fog Infrastructures for Transportation Cyber-Physical Systems (T-CPS)
Authors: Hussain Md Muzakkir , Beg M.M. S
Published: April 2019

The advent of intelligent vehicular applications and IoT technologies gives rise to data-intensive challenges across different architectural layers of an intelligent transportation system (ITS). Without powerful communication and computational infrastructure, various vehicular applications and services will still stay in the concept phase and cannot be put into practice in daily life. The current cloud computing and cellular set-ups are far from perfect because they are highly dependent on, and bear the cost of additional infrastructure deployment. Thus, the geo-distributed ITS components require a paradigm shift from centralized cloud-scale processing to edge centered fog computing (FC) paradigms. FC outspreads the computing facilities into the edge of a network, offering location-awareness, latency-sensitive monitoring, and intelligent control. In this article, the authors identify the mission-critical computing needs of the next generation ITS applications and highlight the scopes of FC based solutions towards addressing them. Then, the authors discuss the scenarios where the underutilized communication and computational resources available in connected vehicles can be brought in to perform the role of FC infrastructures. Then the authors present a service-oriented software architecture (SOA) for FC-based Big Data Analytics in ITS applications. The authors also provide a detailed analysis of the potential challenges of using connected vehicles as FC infrastructures along with future research directions.
Classification of Brain Hemorrhages in MRI Using Naïve Bayes- Probabilistic Kernel Approach
Authors: Kakhandaki Nita , Kulkarni Shrinivas B , Ramesh K.  , Kulkarni Umakant P
Published: April 2019

A brain hemorrhage is one type of stroke, which is caused due to artery burst in the brain, killing the brain cells due to bleeding. Therefore, to reduce the criticality among the patients, for treatment, the doctors depend on accurate reports on the location of hemorrhage. Magnetic resonance imaging (MRI) is one of the best imaging modality when functional and structural abnormalities need to be found. To aid the identification of presence of abnormality, a novel NB-PKC algorithm for effective recognition of brain hemorrhages in MRI is proposed. A series of preprocessing is done, then the image undergoes binary thresholding process for applying an image mask on the hemorrhage region. Then for segmentation a modified multi-level segmenting algorithm is applied, using minimal local binary pattern and GLCM, combined features are extracted and finally for classification a novel Naïve Bayes- Probabilistic Kernel Classification is applied. These techniques designed could accurately identify the position and classified whether the image had an abnormality or not and could reduce human errors.
Feeding behavior of sheep fed sugarcane silage enriched with detoxified castor bean meal
Authors: Oliveira Aline Carsoso , Garcia Rasmo , Almeida Vitor Visintin Silva de , Oliveira Hellenn Cardoso , Silva Robério Rodrigues , Lima Júnior Dorgival Morais de
Published: April 2019

The aim of this study was to evaluate the feeding behavior of sheep fed sugarcane silage enriched with increasing levels of detoxified castor bean meal. Twenty-four non-castrated male Santa Inês sheep with an average body weight of 25.34 kg and four months of age, were distributed in four treatments - 0, 7, 14 and 21% of the natural matter of detoxified castor bean meal in sugarcane silage. There was a linear increase (p < 0.05) in time spent eating and feeding and rumination efficiency (g MS and NDF/h) with the inclusion of castor bean meal in silage. However, there was a linear decreasing response for time spent resting (p < 0.05). Time spent ruminating, number of boluses per day and numbers of chews per day per bolus were not affected (p > 0.05) by the inclusion of castor bean meal. The addition of detoxified castor bean meal to sugarcane silage reduces time spent eating and increases feed and rumination efficiency in sheep.
Morphological and structural characteristics of Urochloa decumbens Stapf. deferred pasture grazed by heifers under two periods of protein-energy supplementation
Authors: Silva Pedro Henrique Ferreira da , Carvalho Carlos Augusto Brandão de , Malafaia Pedro , Garcia Felipe Zumkeller , Barbero Rondineli Pavezzi , Ferreira Robson Leandro
Published: April 2019

The aim of this study was to evaluate the morphological and structural characteristics of deferred Urochloa decumbens Stapf. ‘Basilisk’ grazed by Nellore heifers under two periods of protein and energy supplementation (PES). The experiment was carried out from Jun 21 to Nov 15, 2016, under a completely randomized design and two PES periods (55 [P55] and 147 [P147] days). Forage mass (FM), leaf blade dry mass (LBDM), stem dry mass (SDM), dead material dry mass (DMDM), canopy height (CH), and forage bulk density (FBD) were evaluated. Data were analyzed by the SAS® PROC MIXED procedure and treatment means were compared with the Student's t test (p < 0.05). LBDM was higher for P147 heifers after 21, 84, and 126 days of grazing, similar to those observed after 63 days, and was higher for P55 heifers at 42, 105, and 147 days of grazing. SDM was lower for P147 heifers after 21, 42, 105, and 126 days, and similar in the other grazing periods. Protein and energy supplementation for heifers over 147 days resulted in a lower stem mass of U. decumbens Stapf. ‘Basilisk’ deferred pastures.
‘Panela velha é que faz comida boa’: tópica e inversão de tópica na poesia lírica grega
Authors: Silva Luiz Carlos André Mangia
Published: April 2019

No acervo de epigramas do livro V da Antologia Grega ou Palatina podemos encontrar diferentes grupos de poemas relacionados entre si pelo uso reiterado das mesmas tópicas ou lugares-comuns, constituindo assim subgêneros líricos. Focalizaremos 10 poemas circunscritos, respectivamente, à tópica da ‘profecia ameaçadora’, à do ‘regozijo com o cumprimento da profecia’ e àquela que denominaremos ‘panela velha, comida boa’ (esta última uma inversão das expectativas tradicionais), a fim de demonstrar a relação existente entre os três tipos de tópicas e os processos de inovação próprios da poética antiga.
Zinc Oxide/ Silver Sulfide (ZnO/Ag2S) Core-Shell Type Composite for Wide Range Absorption of Visible Spectra: Synthesis and Characterization
Authors: Babeer Afaf Mohammad , Aamir Lubna
Published: April 2019

This work presents the synthesis of zinc oxide /silver sulfide (ZnO/Ag2S) core/shell type composite; using combined wet chemical precipitation method and ion exchange mechanism; for wide range absorption of visible spectra by the composite. Synthesis is performed in three steps. In the first step; ZnO nanoparticles (nanocores) are produced, in the second step; ZnS layer is deposited over ZnO nanocores and in the third step; Zn from ZnS is replaced by Ag to form Ag2S shell over ZnO; using ion exchange mechanism. The presence of reflection peaks of ZnO and Ag2S in XRD spectra confirms the formation of ZnO/Ag2S composite. SEM image of ZnO shows the formation of near spherical ZnO nanoparticles of diameter in range 256nm to 584nm with a smooth surface, while SEM image of ZnO/Ag2S composite shows the formation of Ag2S layer over ZnO cores as indicated by rougher and contrasted surface as compared to bare ZnO cores. Also, the size of composite particles became larger than ZnO nanocores (100µm-200µm), which further confirms the formation of Ag2S shell over ZnO nanocores. The optical absorption spectrums of both ZnO and ZnO/Ag2S composite clearly indicate that synthesized composite absorb strongly in UV to IR region of the electromagnetic spectrum as compared to ZnO nanocores; which absorb only in UV region. Therefore, the synthesized composite could be used as a photovoltaic material.
Long Term Well Plug Integrity Assurance – A Probabilistic Approach
Authors: Willis Brian Mathew , Strutt John Edward , Eden Robert David
Published: April 2019

Well plugging and abandonment (P&A) poses significant long-term risks for the industry with thousands of onshore and offshore wells requiring P&A in the coming decades. Historically, operators have typically followed a prescribed P&A approach to meet regulatory requirements. However, a risk-based approach allows bespoke abandonment strategies for individual wells, with the potential to reduce the time and effort needed for low-risk wells, while justifying any necessary additional P&A resources for managing higher risk wells. An advance computational risk-based, predictive well integrity model, STEM-flow, has been developed to support risk-based P&A and new plug technology qualification, and to compliment an extensive material test programme for structural bismuth alloys for plugging and abandonment and carried out as part of a collaborative research program.

The model enables assessment of leak paths and leak rates with time, addressing multiple plugs and well barrier elements, degradation of barrier materials, cross-flow potential and reservoir re-pressurization. The mathematical model is based on a connectivity matrix, whose elements are effective permeability values, derived from well barrier models, which separate isolated pressurized zones, along a potential leak pathway. Key elements of the approach include the focus on fundamental models for barrier failure mechanisms and the handling of uncertain model parameters through Monte Carlo Simulation to calculate statistical life and probability of failure of plugs and complete well P&A designs. The paper outlines the approach employed by STEM-flow for evaluating and comparing the effectiveness of different P&A designs, plugging technologies, cement plugs and new sealing materials such as creep resisting structural bismuth alloys. Two cases are studied, involving the prediction of plug life and overall life of a specific well P&A design. These cases compare a typical well P&A design for a subsea well in the Central North Sea using conventional cement barriers with that of structural bismuth alloy plugs under development.
Polymers for EOR in Offshore Reservoirs: Recommended Practices for Laboratory Screening
Authors: Araujo de Itriago Yani Carolina , Araujo Fresky Mariela
Published: April 2019

Most EOR methods, and hence most EOR screening criteria, traditionally focus on onshore applications due to lower cost and complexity in the implementation. Despite the challenges associated to offshore environments, EOR application in offshore fields is receiving increasing attention since the size of the prize is significantly large to overcome the high costs associated to the development.

The oil and gas community is evaluating and testing potential applications of chemical EOR to offshore assets based on the need to develop increasingly deeper reservoirs. Some of these reservoirs are characterized by having relative high temperature and high salinity, conditions where most available chemicals for EOR have limited applicability. Recent efforts to develop high temperature polymers have been reported, however, there is no clear understanding of what would work best in those harsh environments.

In this work, we propose an integrated workflow for laboratory screening of polymers for application in offshore reservoirs with high temperature and high salinity. We provide an overview of the main steps of the workflow and recommended protocols for the different laboratory measurements. The proposed workflow has been derived from best practices reported in the literature and our experimental work over the last two decades. We also provide a summary of the latest polymers developed for application in high temperature and high salinity reservoirs and point out the required testing that we recommend for an appropriate screening of chemicals for offshore EOR applications.

Each of the steps of the recommended workflow is described showing with actual data the limitations used in some prior screening work. We emphasize the need to move away from ‘ideal’ lab conditions by using representative rock and fluid samples and doing the experiments at reservoir conditions of pressure, temperature and representative saturation, and to consider a variety of scenarios for the testing that describe the expected changes that the polymer solutions will experience during their lifetime in the application, and give a list of the minimal testing needed to get a proper understanding of the potential polymer performance.

We provide recommendations on the best available polymers for EOR application in offshore assets to date. In summary, for temperatures greater than 95°C and salinity above 90,000 ppm standard polymers like acrylamide, polyacrylamide and partially hydrolyzed polyacrylamide (HPAM) cannot be used, and the promising newly developed polymers include modifications of acrylamide, thermal associated polymers and HPAM functionalized with AMPS monomers.

In this study, it has been developed an integrated workflow for laboratory screening of polymers for EOR applications in offshore assets and provide recommendations for the selection of polymers for use in high temperature and high salinity assets.
The search for a moral compass and a new social contract in the context of citizenship education
Authors: Van der Walt Johannes L.
Published: April 2019

Some observers regard South Africa as one of the most violent, lawless and morally depraved societies in the world. Several other countries around the world can be shown to be similarly afflicted. In South Africa’s case, this condition might be because of political transformation, particularly the lingering effects of the struggle against past injustices (apartheid, racism) inflicted on sections of the population. The social instability has been exacerbated by an influx of migrants and a resultant increase in diversity. One way of attempting to assuage this situation is to harness the school subject known as ‘citizenship education’ for guiding the upcoming generations into committing to a new moral compass, that is, awareness or consciousness with a conscience, and to an accompanying new social contract. Finding a rationale for such a moral compass and social contract that all the citizens of South Africa and of other similarly stricken countries would be prepared to commit to is a daunting task because people tend to be subjective in reflecting about their personal and group views, particularly about their religious beliefs and convictions. Closer examination reveals, however, that despite all the diversity, differences and conflict prevalent in societies, people are potentially able to share a set of basic values that arguably could form the core of the sought-for moral compass. Citizenship education could be functional in bringing home to the next generation the notion of henceforth living in accordance with the precepts of such a moral compass and social contract.
Волновая модель метрических пространств
Authors: Belishev Mikhail Igorevich , Simonov Sergey Aleksandrovich
Published: April 2019

Пусть $\Omega$ - метрическое пространство, $A^t$ - метрическая окрестность множества $A\subset\Omega$ радиуса $t$, $\mathfrak O$ - решетка открытых в $\Omega$ множеств с частичным порядком $\subseteq$ и порядковой сходимостью. Решетка $\mathfrak O$-значных функций от $t\in(0,\infty)$ с поточечными частичным порядком и сходимостью содержит семейство ${I\mathfrak
O}=\{A( \boldsymbol\cdot )\mid A(t)=A^t, A\in\mathfrak{O}\}$. Пусть $\widetilde\Omega$ есть множество атомов порядкового
замыкания $\overline{I\mathfrak O}$. Мы описываем класс пространств, для которых множество $\widetilde\Omega$, снабженное
адекватной метрикой, оказывается изометричным исходному пространству $\Omega$.
Пространство $\widetilde\Omega$ - это ключевой элемент конструкции волнового спектра симметрического полуограниченного
оператора, предложенной в работе одного из авторов. В ней намечена программа построения функциональной модели операторов
указанного класса. Настоящая статья - шаг в реализации этой программы.
О комплексно-сопряженных нулях частичной тэта-функции
Authors: Kostov Vladimir Petrov
Published: April 2019

Мы показываем, что для любого $q\in (0,1)$ все пары комплексно-сопряженных нулей частичной тета-функции $\theta (q,x):=\sum _{j=0}^{\infty}q^{j(j+1)/2}x^j$ принадлежат множеству
$\{x:\operatorname{Re}x\in (-5792{,}7,0), |\operatorname{Im}x|<132\}\cup\{x:|x|<18\}$, а для любого $q\in (-1,0)$ они принадлежат прямоугольнику $\{x:|\operatorname{Re}x|< 364{,}2, |\operatorname{Im}x|<132\}$.
Формула следа для дифференциального оператора высокого порядка на отрезке при возмущении младшего коэффициента конечным зарядом
Authors: Gal'kovskii Egor Denisovich
Published: April 2019

В работе получена формула регуляризованного следа для дифференциального оператора высокого порядка на отрезке при возмущении младшего коэффициента конечным зарядом. Рассмотрены произвольные регулярные краевые условия и произвольный порядок оператора $n\geqslant 3$. Обнаружен новый эффект: при четном порядке оператора появляется дополнительное слагаемое, учитывающее скачок функции распределения заряда в середине отрезка.
Разветвленные накрытия многообразий и $\boldsymbol{nH}$-пространства
Authors: Gugnin Dmitry Vladimirovich
Published: April 2019

Мы показываем, что на сфере $S^m$, $m\ne 1,3,7$, существует $n_m$-значное умножение с единицей для некоторого $n_m\in\{2,4,8\}$. Также мы в явном виде строим $2^{k-1}$-листное разветвленное накрытие произведения $k$ штук сфер $S^{m_1}\times \cdots \times S^{m_k}$ над сферой $S^m$, $m=m_1+\cdots+m_k$.
Anemia, Iron Deficiency, and Iron Supplementation in Relation to Mortality among HIV-Infected Patients Receiving Highly Active Antiretroviral Therapy in Tanzania
Authors: Haider Batool A. , Spiegelman Donna , Hertzmark Ellen , Sando David , Duggan Christopher , Makubi Abel , Sudfeld Christopher , Aris Eric , Chalamilla Guerino E. , Fawzi Wafaie W.
Published: April 2019

Anemia in HIV-infected patients improves with highly active antiretroviral therapy (HAART); however, it may still be associated with mortality among patients receiving treatment. We examined the associations of anemia severity and iron deficiency anemia (IDA) at HAART initiation and during monthly prospective follow-up with mortality among 40,657 adult HIV-infected patients receiving HAART in Dar es Salaam, Tanzania. Proportional hazards models were used to examine the associations of anemia severity and IDA at HAART initiation and during follow-up with mortality. A total of 6,261 deaths were reported. Anemia severity at HAART initiation and during follow-up was associated with an increasing risk of mortality (trend tests P < 0.001). There was significantly higher mortality risk associated with IDA at HAART initiation and during follow-up versus no anemia or iron deficiency (both P < 0.001). These associations differed significantly by gender, body mass index, and iron supplement use (all interaction test P < 0.001). The magnitude of association was stronger among men. Mortality risk with severe anemia was 13 times greater versus no anemia among obese patients, whereas it was only two times greater among underweight patients. Higher mortality risk was observed among iron supplement users, irrespective of anemia severity. Anemia and IDA were significantly associated with a higher mortality risk in patients receiving HAART. Iron supplementation indicated an increased mortality risk, and its role in HIV infections should be examined in future studies. Given the low cost of assessing anemia, it can be used frequently to identify high-risk patients in resource-limited settings.
Antibiotic-Resistant Escherichia coli in Drinking Water Samples from Rural Andean Households in Cajamarca, Peru
Authors: Larson Anika , Hartinger Stella Maria , Riveros Maribel , Salmon-Mulanovich Gabriela , Hattendorf Jan , Verastegui Hector , Huaylinos Maria Luisa , Mäusezahl Daniel
Published: April 2019

Antibiotic resistance in pathogenic bacteria is a serious public health issue. The growing threat is a cause for concern and action to prevent the emergence of new resistant strains and the spread of existing ones to humans via the environment. This study aimed at identifying fecal pathogens in drinking water obtained from rural Andean households from Cajamarca, Peru, and measuring the antibiotic resistance profile of Escherichia coli. The study was embedded within a community-randomized controlled trial among 102 communities in the northern highlands of the Cajamarca region, Peru. Of 314 samples, 55.4% (95% CI [49.7, 61.0], n = 174) were identified as thermotolerant coliforms. Among the samples positive for thermotolerant coliform, E. coli was isolated in 37.3% (n = 117), Klebsiella spp. in 8.0% (n = 25), Enterobacter spp. in 5.1% (n = 16), and Citrobacter spp. in 2.5% (n = 8). Of the 117 E. coli samples, 48.7% (95% CI [39.4, 58.1], n = 57) showed resistance to any antibiotic. The E. coli antibiotic resistance profile showed highest resistance against tetracycline (37.6%), ampicillin (34.2%), sulfamethoxazole–trimethoprim (21.4%), and nalidixic acid (13%). Some 19.7% (95% CI [12.9, 28.0], n = 23) of the E. coli isolates displayed multidrug resistance, defined as resistance to at least three classes of antibiotics. The CTX-M-3 gene, which encodes extended-spectrum resistance to beta-lactamase antibiotics, was found in one isolate. The high prevalence of fecal contamination in drinking water highlights the importance of household water treatment methods. Likewise, the high levels of antibiotic resistance found indicate a need for further research to identify the origins of potential environmental contamination, misuse, or inadequate disposal of antibiotics.
Multiple Praziquantel Treatments of Schistosoma mansoni Egg-Negative, CCA-Positive Schoolchildren in a Very Low Endemic Setting in Egypt Do Not Consistently Alter CCA Results
Authors: Haggag Ayat A. , Casacuberta Partal Miriam , Rabiee Amal , Abd Elaziz Khaled M. , Campbell Carl H. , Colley Daniel G. , Ramzy Reda M. R.
Published: April 2019

Forty-four Schistosoma mansoni egg-negative/circulating cathodic antigen (CCA) low-positive (trace or 1+) children in three districts of very low prevalence in Egypt were given three sequential praziquantel (PZQ) treatments. Stool and urine specimens were collected 3 months following the initial treatment, and 3 weeks following the second and following the third PZQ treatments, which were conducted 5 weeks apart. Stool specimens were examined by Kato–Katz (four slides/stool sample) and all S. mansoni egg-negative stools were further tested by the “miracidia hatching test” (MHT). Urine samples were examined by the point-of-care CCA assay (POC-CCA). Over the study period, all stool samples from study subjects remained S. mansoni egg negative and MHT negative. Of the POC-CCA test results, in the first day of the study 3 months following the initial treatment, 29.5% were negative, 61.4% CCA trace positives, and 9.1% CCA 1+ positives. Following each PZQ treatment, the test results fluctuated between 1+, trace, and negative, but did not consistently decrease. The proportions of POC-CCA–positive results obtained in the first day (70.5%) as compared with the last day of the study (72.7%) in all of the three districts were very similar. We conclude that CCA trace and 1+ readings, in Kato–Katz S. mansoni egg-negative children in this area with very low levels of intestinal schistosomiasis, are not consistently altered or rendered consistently negative following repeated PZQ treatments and are therefore likely to represent false-positive readings. This finding is of critical importance for countries such as Egypt as they approach elimination.
A Interdisciplinaridade constituindo o discurso pedagógico na Formação de Professores de Química em um curso preparatório para o ENEM
Authors: Silva Josiele Oliveira da , Ferreira Maira
Published: April 2019

O trabalho refere-se à formação de professoras de Química do projeto de extensão Desafio Pré-vestibular da UFPel, considerando os discursos sobre interdisciplinaridade nas ações de ensino e buscando analisar o modo como essas professoras percebem as ações interdisciplinares no curso. A pesquisa, de caráter qualitativo, foi realizada com as docentes que participaram do projeto no ano de 2015. Os resultados mostram que o discurso pedagógico que valoriza a interdisciplinaridade no ensino de Química, presente nos documentos oficiais, é referido também neste espaço de ensino, como sendo adequado em se tratando de um projeto de Educação Popular. A preparação autônoma e cidadã dos sujeitos provocam nos professores dificuldades em realizar práticas pedagógicas com essa dimensão, considerando ser um curso de Educação Popular preparatório para o ENEM, cuja ênfase é em conteúdos específicos de Química.
Imaginário, mídias e formação: o que pode o professor no espaço universitário?
Authors: Fortes de Oliveira Valeska Maria , Alves da Silveira de Vasconcellos Vanessa
Published: April 2019

O texto que ora apresentamos faz uma reflexão sobre as mídias referenciada no campo do imaginário social, na qual discutimos nossas invenções midiáticas e as relações que criamos com elas. A empiria que expomos nesta discussão trata dos professores universitários, suas relações e as imagens, que são produzidas com base nas significações construídas frente ao estudante e à aula universitária, a fim de compreender as suas práticas pedagógicas a partir do imaginário social. Os docentes universitários que fizeram parte da investigação, e que aqui são centro do debate, participaram do Curso de Formação e Desenvolvimento Pessoal e Profissional Docente, desenvolvido pela Unidade de Apoio Pedagógico (UAP) do Centro de Ciências Rurais (CCR) da Universidade Federal de Santa Maria (UFSM). Evidencia-se que a abordagem metodológica escolhida para a construção da investigação baseou-se no enfoque biográfico, que oportunizou aos professores pensar, refletir e tomar consciência dos saberes e fazeres que estão construindo na docência, (re)significando suas práticas. Compartilhar e produzir conhecimento em um espaço/tempo referenciado no campo do imaginário social é um convite e um exercício constante de pensar o que instituímos como nosso, como sociedade que somos. Dessa forma, acreditamos que, nessa relação, a leitura do instituído prevê também um instituinte, inventando outras formas de ensino e de aprendizagem no espaço universitário, bem como outras formas de ser professor e viver numa sociedade da cultura de mídias.
Reviews and syntheses: Dams, water quality and tropical reservoir stratification
Authors: Winton Robert Scott , Calamita Elisa , Wehrli Bernhard
Published: April 2019

Abstract. The impact of large dams is a popular topic in environmental
science, but the importance of altered water quality as a driver of ecological impacts is
often missing from such discussions. This is partly because information on the
relationship between dams and water quality is relatively sparse and fragmentary,
especially for low-latitude developing countries where dam building is now concentrated.
In this paper, we review and synthesize information on the effects of damming on water
quality with a special focus on low latitudes. We find that two ultimate physical
processes drive most water quality changes: the trapping of sediments and nutrients, and
thermal stratification in reservoirs. Since stratification emerges as an important driver
and there is ambiguity in the literature regarding the stratification behavior of water
bodies in the tropics, we synthesize data and literature on the 54 largest low-latitude
reservoirs to assess their mixing behavior using three classification schemes. Direct
observations from literature as well as classifications based on climate and/or
morphometry suggest that most, if not all, low-latitude reservoirs will stratify on at
least a seasonal basis. This finding suggests that low-latitude dams have the potential
to discharge cooler, anoxic deep water, which can degrade downstream ecosystems by
altering thermal regimes or causing hypoxic stress. Many of these reservoirs are also
capable of efficient trapping of sediments and bed load, transforming or destroying
downstream ecosystems, such as floodplains and deltas. Water quality impacts imposed by
stratification and sediment trapping can be mitigated through a variety of approaches,
but implementation often meets physical or financial constraints. The impending
construction of thousands of planned low-latitude dams will alter water quality
throughout tropical and subtropical rivers. These changes and associated environmental
impacts need to be better understood by better baseline data and more sophisticated
predictors of reservoir stratification behavior. Improved environmental impact
assessments and dam designs have the potential to mitigate both existing and future
potential impacts.
Major role of ammonia-oxidizing bacteria in N2O production in the Pearl River Estuary
Authors: Ma Li , Lin Hua , Xie Xiabing , Dai Minhan , Zhang Yao
Published: April 2019

Abstract. Nitrous oxide (N2O) has significant global warming potential as a greenhouse gas. Estuarine and coastal regimes are the major zones of N2O production in the marine system. However, biological sources of N2O in estuarine ecosystems remains controversial, but is of great importance for understanding the global N2O emission patterns. Here, we measured concentrations and isotopic compositions of N2O as well as distributions and transcript levels of ammonia-oxidizing bacterial and archaeal amoA and denitrifier nirS genes by quantitative polymerase chain reaction along a salinity gradient in the Pearl River Estuary, and performed in situ incubation experiments to estimate N2O yields. Our results indicated that nitrification predominantly occurred, with significant N2O production during ammonia oxidation, in the hypoxic waters of the upper estuary where the maximum N2O and △N2O concentrations were observed, although minor denitrification might be concurrent at the site with the lowest dissolved oxygen. Ammonia-oxidizing β-proteobacteria (AOB) were significantly positively correlated with all N2O parameters, although their amoA gene abundances were distinctly lower than ammonia-oxidizing Archaea (AOA) throughout the estuary. Furthermore, the N2O production rate and the N2O yield normalized to amoA gene copies or transcripts estimated a higher relative contribution of AOB to the N2O production in the upper estuary. Taken together, the in situ incubation experiments, N2O isotopic composition and concentrations, and gene datasets suggested that the high concentration of N2O (oversaturated) is mainly produced from strong nitrification by the relatively high abundance of AOB in the upper reaches as the major source of N2O emitted to the atmosphere in the whole estuary.
Strong correspondence between nitrogen isotope composition of foliage and chlorin across a rainfall gradient: Implications for paleo-reconstruction of the nitrogen cycle
Authors: Goulden Sara K. E. , Ohkouchi Naohiko , Freeman Katherine H. , Chikaraishi Yoshito , Ogawa Nanako O. , Suga Hisami , Chadwick Oliver , Houlton Benjamin Z.
Published: April 2019

Abstract. Nitrogen (N) availability influences patterns of terrestrial productivity and global carbon cycling, imparting strong but poorly resolved feedbacks on Earth's climate system. Central questions concern the timescale of N cycle response to elevated CO2 concentration in the atmosphere, and whether availability of this limiting nutrient increases or decreases with climate change. Nitrogen isotopic composition of bulk plant leaves provides information on large-scale patterns of N availability in the modern environment. Here we examine the utility of chlorins, degradation products of chlorophylls, hypothesized to persist in soil subsequent to plant decay, as proxies for reconstructing past plant δ15N. Specifically, we test the hypothesis that δ15N of plant leaves (δ15Nleaf) is recorded in δ15N of pheophytin a (δ15Npheo) along the leaf-litter-soil continuum across an array of ecosystem climate conditions and plant functional types (C3, C4, legumes, and woody plants). The δ15N of live foliage and bulk soil display marked declines with increasing rainfall, consistent with past studies in Hawaii and patterns worldwide. We find measurable chlorin concentrations along soil-depth profiles at all sites, with pheophytin a present in amounts required for isotopic analysis (> 10 nmol). δ15Npheo in leaves, litter, and soil track δ15Nleaf of plant leaves. We find potential for δ15Npheo records from soil to provide proxy information on δ15Nleaf.
Joint state-parameter estimation of a nonlinear stochastic energy
balance model from sparse noisy data
Authors: Lu Fei , Weitzel Nils , Monahan Adam H.
Published: April 2019

Abstract. While nonlinear stochastic partial differential equations arise naturally in spatiotemporal modeling, inference for such systems often faces two major challenges: sparse noisy data and ill-posedness of the inverse problem of parameter estimation. To overcome the challenges, we introduce a strongly regularized posterior by normalizing the likelihood and by imposing physical constraints through priors of the parameters and states. We investigate joint parameter-state estimation by the regularized posterior in a physically motivated nonlinear stochastic energy balance model (SEBM) for paleoclimate reconstruction. The high-dimensional posterior is sampled by a particle Gibbs sampler that combines MCMC with an optimal particle filter exploiting the structure of the SEBM. In tests using either Gaussian or uniform priors based on the physical range of parameters, the regularized posteriors overcome the ill-posedness and lead to samples within physical ranges, quantifying the uncertainty in estimation. Due to the ill-posedness and the regularization, the posterior of parameters presents a relatively large uncertainty, and consequently, the maximum of the posterior, which is the minimizer in a variational approach, can have a large variation. In contrast, the posterior of states generally concentrates near the truth, substantially filtering out observation noise and reducing uncertainty in the unconstrained SEBM.