Search results for: Atlantic Bluefin tuna

Authors: Volkan Uygun, H. Birkan Yilmaz, Tuna Tugcu

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This study focuses on the development and use of algorithms that address the issue of resource management in response to emergency and disaster situations. The presented system, named Disaster Management Platform (DMP), takes the data from the data sources of service providers and distributes the incoming requests accordingly both to manage load balancing and minimize service time, which results in improved user satisfaction. Three different resource management algorithms, which give different levels of importance to load balancing and service time, are proposed for the study. The first one is the Minimum Distance algorithm, which assigns the request to the closest resource. The second one is the Minimum Load algorithm, which assigns the request to the resource with the minimum load. Finally, the last one is the Hybrid algorithm, which combines the previous two approaches. The performance of the proposed algorithms is evaluated with respect to waiting time, success ratio, and maximum load ratio. The metrics are monitored from simulations, to find the optimal scheme for different loads. Two different simulations are performed in the study, one is time-based and the other is lambda-based. The results indicate that, the Minimum Load algorithm is generally the best in all metrics whereas the Minimum Distance algorithm is the worst in all cases and in all metrics. The leading position in performance is switched between the Minimum Distance and the Hybrid algorithms, as lambda values change.

Keywords: emergency and disaster response, resource management algorithm, disaster situations, disaster management platform

Procedia PDF Downloads 314

Authors: Carl van Walraven, Meltem Tuna

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Background: Network meta-analysis (NMA) quantifies the relative efficacy of 3 or more interventions from studies containing a subgroup of interventions. This study applied the analytical approach of NMA to quantify the relative accuracy of prediction models with distinct inclusion criteria that are evaluated on a common population (‘concurrent external validation’). Methods: We simulated binary events in 5000 patients using a known risk function. We biased the risk function and modified its precision by pre-specified amounts to create 15 prediction models with varying accuracy and distinct patient applicability. Prediction model accuracy was measured using the Scaled Brier Score (SBS). Overall prediction model accuracy was measured using fixed-effects methods that accounted for model applicability patterns. Prediction model accuracy was summarized as the Network Relative Model Accuracy (NeRMA) Score which ranges from -∞ through 0 (accuracy of random guessing) to 1 (accuracy of most accurate model in concurrent external validation). Results: The unbiased prediction model had the highest SBS. The NeRMA score correctly ranked all simulated prediction models by the extent of bias from the known risk function. A SAS macro and R-function was created to implement the NeRMA Score. Conclusions: The NeRMA Score makes it possible to quantify the accuracy of binomial prediction models having distinct inclusion criteria in a concurrent external validation.

Keywords: prediction model accuracy, scaled brier score, fixed effects methods, concurrent external validation

Procedia PDF Downloads 180

Authors: Lhoussain Simour

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This paper discusses the reordering and reorientation Moroccan Oossified and frozen histories in national and colonial archives. It attempts to reexamine Moroccan non-canonical voices beyond borders, their forgotten experiences and itineraries, with the aim of uncovering cultural discourses pertaining to early cultural and artistic interactions between Morocco and the western countries, namely Britain and America. In fact, less attention has been given to the presence of Moroccan entertainers beyond borders in the archives of history. Moroccan historians and cultural critics seem to have paid little critical consideration to Moroccan artistic encounters with the west, Europe and America as a case in point. They have overlooked to deal with travel performances, professional entertainments, and artistic spectacles, initiated by acrobats, as instances of visual cross-cultural encounters between Morocco and the west. The narratives of these professional artists have hardly found their ways into historiographical writing. This contribution attempts to locate the contesting beginnings of Moroccan professional entertainers in western show business in the nineteenth century which witnessed intricate artistic, discursive and cultural junctures by emphasizing connections between theatrical performances, ethnic exhibition and world fair expositions. Moroccan professional performances grew in Europe and America within a zealous context marked by the rise of a paradigmatic racial consciousness that sought to authenticate and legitimate ethnic discourses of power and exclusion. The ethnic taxonomies and racial hierarchies governed by ethnographic and anthropological documentation fueled up entertainment venues and popular theatrical performances and helped in developing a distinctive view about Self and Other paradigms. Moroccan travelers started their journeys to visit European and American countries to exhibit their acrobatics acts. They, in a certain sense, continued, albeit in varying degrees and circumstances, the whole tradition of travel initiated previously by their ancestor diplomats and ambassadors. Professional entertainers embarked on daring journeys across the Mediterranean and the Atlantic to discover new geographies and cultural spaces, and perform their spectacles beyond borders. These travelers left rich archival documents that reflect important cultural and historical moments. The routes of travel started from the margins of the empire towards metropolitan centers of nineteenth century Europe and America included Moroccan women travelers as acrobats and dancing professional artists as well. These also crossed the straits of Gibraltar and journeyed through the Atlantic Ocean to visit western countries. Moroccan women travelers took part in various Euro-American theatre performances and in circus shows as early as 1850 according to newspapers archives and passengers shipping lists. Najat Amburg, Zahar Ben Tahar, Torquia, Fadma, and many more whose names are now lost to us, moved freely in various western capital cities to entertain nineteenth century western audiences.

Keywords: archives, cultural encounters, self and other, Morocco, travel, Moroccan acrobats, Moorish dancing women

Procedia PDF Downloads 145

Authors: Rujnan Tuna, Ayse Cil Akinci

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Work life takes up an important place in human life, and an employed person faces many stimuli from internal and external environments and is affected by them in a positive or negative way. Also, the handover process, which is the process of sharing information about the patient with other health professionals, is an important criterion to maintain patient care and enhance the quality of care provided. Handover is a key component for sustaining daily basic clinical practices and is also essential to maintain the safe patient care. This investigation followed a descriptive and correlation design in order to establish job stress and the handover efficiency of nurses and the relationship in between. The study was conducted with 192 nurses working in a public hospital in Istanbul between January and March 2017. Descriptive information form, Job Stressors Scale, and Handover Evaluation Scale were used to collect the data of the study. The data were analyzed by using IBM SPSS Statistics 22.0 statistical software. Approvals from participants, managers of institution, and ethics committee were taken for the study. As a result of the research, it was found that job stress was above the median value, and the highest score in the ‘work role conflict’ subdimension. Also, it was found that the effectiveness of the nurses' handover effectiviness was above the median value and the highest score in the ‘quality of information’ subdimension. In the study, there was a negatively weak correlation between ‘work role overload’ subdimension of Job Stressors Scale and ‘interaction and support’ subdimension of Handover Evaluation Scale. There is a need for further study in order to maintain patient safety.

Keywords: handover, job stress, nurse, patient

Procedia PDF Downloads 134

Authors: Ronald Mraz, Gary C. Kessler, Ethan Gold, John G. Cline

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The International Ice Patrol (IIP) continually monitors iceberg activity in the North Atlantic by direct observation using ships, aircraft, and satellite imagery. Daily reports detailing navigational boundaries of icebergs have significantly reduced the risk of iceberg contact. What is currently lacking is formatting this data for automatic transmission and display of iceberg navigational boundaries in commercial navigation equipment. This paper describes the methodology and implementation of a system to format iceberg limit information for dissemination through existing radio network communications. This information will then automatically display on commercial navigation equipment. Additionally, this information is reformatted for Google Earth rendering of iceberg track line limits. Having iceberg limit information automatically available in standard navigation equipment will help support full autonomous operation of sailing vessels.

Keywords: iceberg, iceberg risk, iceberg track lines, AIS messaging, international ice patrol, North American ice service, google earth, autonomous surface vessels

Procedia PDF Downloads 107

Authors: Luther Ollier, Sylvie Thiria, Anastase Charantonis, Carlos E. Mejia, Michel Crépon

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Sea Surface Height Anomaly (SLA) is a signature of the sub-mesoscale dynamics of the upper ocean. Sea Surface Temperature (SST) is driven by these dynamics and can be used to improve the spatial interpolation of SLA fields. In this study, we focused on the temporal evolution of SLA fields. We explored the capacity of deep learning (DL) methods to predict short-term SLA fields using SST fields. We used simulated daily SLA and SST data from the Mercator Global Analysis and Forecasting System, with a resolution of (1/12)◦ in the North Atlantic Ocean (26.5-44.42◦N, -64.25–41.83◦E), covering the period from 1993 to 2019. Using a slightly modified image-to-image convolutional DL architecture, we demonstrated that SST is a relevant variable for controlling the SLA prediction. With a learning process inspired by the teaching-forcing method, we managed to improve the SLA forecast at five days by using the SST fields as additional information. We obtained predictions of a 12 cm (20 cm) error of SLA evolution for scales smaller than mesoscales and at time scales of 5 days (20 days), respectively. Moreover, the information provided by the SST allows us to limit the SLA error to 16 cm at 20 days when learning the trajectory.

Keywords: deep-learning, altimetry, sea surface temperature, forecast

Procedia PDF Downloads 52

Authors: Umar Albalawi, Sang C. Suh, Jinoh Kim

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As internet continues to expand its usage with an enormous number of applications, cyber-threats have significantly increased accordingly. Thus, accurate detection of malicious traffic in a timely manner is a critical concern in today’s Internet for security. One approach for intrusion detection is to use Machine Learning (ML) techniques. Several methods based on ML algorithms have been introduced over the past years, but they are largely limited in terms of detection accuracy and/or time and space complexity to run. In this work, we present a novel method for intrusion detection that incorporates a set of supervised learning algorithms. The proposed technique provides high accuracy and outperforms existing techniques that simply utilizes a single learning method. In addition, our technique relies on partial flow information (rather than full information) for detection, and thus, it is light-weight and desirable for online operations with the property of early identification. With the mid-Atlantic CCDC intrusion dataset publicly available, we show that our proposed technique yields a high degree of detection rate over 99% with a very low false alarm rate (0.4%).

Keywords: intrusion detection, supervised learning, traffic classification, computer networks

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Authors: Salma Aboussalam, Karima Khalil, Khalid Elkalay

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To describe the structure, functioning, and state of the Moroccan Mediterranean Sea ecosystem, an Ecopath mass balance model has been applied. The model is based on 31 functional groups, containing 21 fishes, 7 invertebrates, 2 primary producers, and one dead group (detritus), which are considered in this work to explore the trophic interaction. The system's average trophic transfer efficiency was 23%. Both the total primary production and total respiration were calculated to be >1, suggesting that more energy is produced than respired in the system. The structure of our system is based on high respiration and consumption flows. Indicators of ecosystem stability and development showed low values of the Finn cycle index (13.97), system omnivory index (0.18), and average Finn path length (3.09), suggesting that our system is disturbed and has a more linear than web-like trophic structure. The keystone index and mixed trophic impact analysis indicated that other demersal invertebrates, zooplankton, and cephalopods had a tremendous impact on other groups and were recognized as keystone species.

Keywords: Ecopath, food web, trophic flux, Moroccan Mediterranean Sea

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Authors: Irfan U. Din

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The growing presence and operational capacity of Islamic State aka Daesh, which emerged in Pak-Afghan region in 2015, poses a serious threat to the already fragile state of the security situation in the region. This paper will shed light on the current state of IS-K network in the Pak-Afghan region and will explain how its presence and operational capacity in the northern and central Afghanistan has increased despite intensive military operations against the group in Nangarhar province – the stronghold of IS-K. It will also explore the role of Pakistani Taliban in the emergence and expansion of IS-K in the region and will unveil the security implication of growing nexus of IS-K and transnational organized groups for the region in Post NATO withdrawal scenario. The study will be qualitative and will rely on secondary and primary data to explore the topic. For secondary data existing literature on the topic will be extensively reviewed while for primary data in-depth interviews will be conducted with subject experts, Taliban commanders, and field researchers.

Keywords: Islamic State of Khorasan (IS-K), North Atlantic Treaty Organization (NATO), Pak-Afghan Region, Transnational Organized Crime (TNOC)

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Authors: Tulio Sulbaran, Sandeep Langar

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Architects are an integral part of the construction industry and are continuously incorporating decisions that influence projects during their life cycle. These decisions aim at selecting best alternative from the ones available. Unfortunately, this decision making process is mainly unexplored in the construction industry. No instrument to measure construction decision, based on knowledgebase of decision-makers, has existed. Additionally, limited literature is available on the topic. Recently, an instrument to gain an understanding of the construction decision-making process was developed by Dr. Tulio Sulbaran from the University of Texas, San Antonio. The instrument’s name is 'Construction Decision Making Inventory (CDMI)'. The CDMI is an innovative idea to measure the 'What? When? How? Moreover, Who?' of the construction decision-making process. As an innovative idea, its statistical validity (accuracy of the assessment) is yet to be assessed. Thus, the purpose of this paper is to describe the results of a case study with architects in the south-east of the United States aimed to determine the CDMI validity. The results of the case study are important because they assess the validity of the tool. Furthermore, as the architects evaluated each question within the measurements, this study is also guiding the enhancement of the CDMI.

Keywords: decision, support, inventory, architect

Procedia PDF Downloads 297

Authors: Rosimeire Araújo Silva, Philip Martin Fearnside

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Extreme droughts and floods in the Amazon have serious consequences for natural ecosystems and the human population in the region. The frequency of these events has increased in recent years, and projections of climate change predict greater frequency and intensity of these events. Understanding the links between these extreme events and different patterns of sea surface temperature in the Atlantic and Pacific Oceans is essential, both to improve the modeling of climate change and its consequences and to support efforts of adaptation in the region. The relationship between sea temperatures and events in the Amazon is much more complex than is usually assumed in climatic models. Warming and cooling of different parts of the oceans, as well as the interaction between simultaneous temperature changes in different parts of each ocean and between the two oceans, have specific consequences for the Amazon, with effects on precipitation that vary in different parts of the region. Simplistic generalities, such as the association between El Niño events and droughts in the Amazon, do not capture this complexity. We investigated the variability of Sea Surface Temperature (SST) in the Tropical Pacific Ocean during the period 1950-2022, using Empirical Orthogonal Functions (FOE), spectral analysis coherence and wavelet phase. The two were identified as the main modes of variability, which explain about 53,9% and 13,3%, respectively, of the total variance of the data. The spectral and coherence analysis and wavelets phase showed that the first selected mode represents the warming in the central part of the Pacific Ocean (the “Central El Niño”), while the second mode represents warming in the eastern part of the Pacific (the “Eastern El Niño The effects of the 1982-1983 and 1976-1977 El Niño events in the Amazon, although both events were characterized by an increase in sea surface temperatures in the Equatorial Pacific, the impact on rainfall in the Amazon was distinct. In the rainy season, from December to March, the sub-basins of the Japurá, Jutaí, Jatapu, Tapajós, Trombetas and Xingu rivers were the regions that showed the greatest reductions in rainfall associated with El Niño Central (1982-1983), while the sub-basins of the Javari, Purus, Negro and Madeira rivers had the most pronounced reductions in the year of Eastern El Niño (1976-1977). In the transition to the dry season, in April, the greatest reductions were associated with the Eastern El Niño year for the majority of the study region, with the exception only of the sub-basins of the Madeira, Trombetas and Xingu rivers, which had their associated reductions to Central El Niño. In the dry season from July to September, the sub-basins of the Japurá Jutaí Jatapu Javari Trombetas and Madeira rivers were the rivers that showed the greatest reductions in rainfall associated with El Niño Central, while the sub-basins of the Tapajós Purus Negro and Xingu rivers had the most pronounced reductions. In the Eastern El Niño year this season. In this way, it is possible to conclude that the Central (Eastern) El Niño controlled the reductions in soil moisture in the dry (rainy) season for all sub-basins shown in this study. Extreme drought events associated with these meteorological phenomena can lead to a significant increase in the occurrence of forest fires. These fires have a devastating impact on Amazonian vegetation, resulting in the irreparable loss of biodiversity and the release of large amounts of carbon stored in the forest, contributing to the increase in the greenhouse effect and global climate change.

Keywords: sea surface temperature, variability, climate, Amazon

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Authors: M. Reza Hashemi, Chris Small, Scott Hayward

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The Northeast Coast of the US faces damaging effects of coastal flooding and winds due to Atlantic tropical and extratropical storms each year. Historically, several large storm events have produced substantial levels of damage to the region; most notably of which were the Great Atlantic Hurricane of 1938, Hurricane Carol, Hurricane Bob, and recently Hurricane Sandy (2012). The objective of this study was to develop an integrated modeling system that could be used as a forecasting/hindcasting tool to evaluate and communicate the risk coastal communities face from these coastal storms. This modeling system utilizes the ADvanced CIRCulation (ADCIRC) model for storm surge predictions and the Simulating Waves Nearshore (SWAN) model for the wave environment. These models were coupled, passing information to each other and computing over the same unstructured domain, allowing for the most accurate representation of the physical storm processes. The coupled SWAN-ADCIRC model was validated and has been set up to perform real-time forecast simulations (as well as hindcast). Modeled storm parameters were then passed to a coastal risk assessment tool. This tool, which is generic and universally applicable, generates spatial structural damage estimate maps on an individual structure basis for an area of interest. The required inputs for the coastal risk model included a detailed information about the individual structures, inundation levels, and wave heights for the selected region. Additionally, calculation of wind damage to structures was incorporated. The integrated coastal risk assessment system was then tested and applied to Charlestown, a small vulnerable coastal town along the southern shore of Rhode Island. The modeling system was applied to Hurricane Sandy and a synthetic storm. In both storm cases, effect of natural dunes on coastal risk was investigated. The resulting damage maps for the area (Charlestown) clearly showed that the dune eroded scenarios affected more structures, and increased the estimated damage. The system was also tested in forecast mode for a large Nor’Easters: Stella (March 2017). The results showed a good performance of the coupled model in forecast mode when compared to observations. Finally, a nearshore model XBeach was then nested within this regional grid (ADCIRC-SWAN) to simulate nearshore sediment transport processes and coastal erosion. Hurricane Irene (2011) was used to validate XBeach, on the basis of a unique beach profile dataset at the region. XBeach showed a relatively good performance, being able to estimate eroded volumes along the beach transects with a mean error of 16%. The validated model was then used to analyze the effectiveness of several erosion mitigation methods that were recommended in a recent study of coastal erosion in New England: beach nourishment, coastal bank (engineered core), and submerged breakwater as well as artificial surfing reef. It was shown that beach nourishment and coastal banks perform better to mitigate shoreline retreat and coastal erosion.

Keywords: ADCIRC, coastal flooding, storm surge, coastal risk assessment, living shorelines

Procedia PDF Downloads 81

Authors: Sila K. Sari, Betty J.L. Laglbauer, Muhammad G. Salim, Irianies C. Gozali, Iqbal Herwata, Fahmi Fahmi, Selvia Oktaviyani, Isabel Ender, Sarah Lewis, Abraham Sianipar, Mark Erdmann

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Taking strides towards the sustainable use of marine stocks requires science-based management of target fish populations and reduction of bycatch in non-selective fisheries. Among elasmobranchs, mobulid rays are faced with high extinction risk due to intrinsic vulnerability to fishing and their conservation has been recognized as a strong priority both in Indonesia and worldwide. Despite their common vulnerabilities to fishing pressure due to slow growth, late maturation and low fecundity, only manta rays, but not devil rays, are protected in Indonesian waters. However, both manta and devil rays are captured in non-selective fisheries, in particular drift gillnets, since their habitat overlaps with fishing grounds for primary target species (e.g. marlin, swordfish and bullet tuna off the coast of Muncar). For this reason, mobulid populations are being heavily impacted, and while national-level protections are crucial to help conservation, they may not suffice alone to insure populations sustainability. In order to assess the potential of applying live-release management measures to conserve mobulids captured as bycatch in drift gillnets, we deployed pop-up survival archival transmitters to assess post-release mortality in Indonesian mobulid rays. We also assessed which fishing practices, in particular, soak duration, affected post-release mortality in order to draw relevant conclusions for management.

Keywords: Mobulid, Devil ray, Manta ray, Bycatch

Procedia PDF Downloads 138

Authors: Naznin Sultana Daisy, Mohammad Hesam Hafezi, Lei Liu

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Nowadays, oily solid waste management has become an important issue for many countries due to frequent oil spill accidents and the increase of industrial oily wastewater. The historical oil spill data show that marine oil spills that affect the shoreline can, in extreme cases, produce up to 30 or 40 times more waste than the volume of oil initially released. Hence, responsive authorities aim to develop the most effective oily waste management solution in a timely manner to manage and minimize the waste generated. In this study initially, we tried to develop the roadmap of oily waste management for three-tiered spill scenarios for Atlantic Canada. For that purpose, three oily waste disposal scenarios are evaluated via six criteria which are determined according to the opinions of the experts from the field. Consequently, through sustainable response strategies, the most appropriate and feasible scenario is determined. The results of this study will assist to develop an integrated oily waste management system for identifying the optimal waste-generation-allocation-disposal schemes and generating the optimal management alternatives based on the holistic consideration of environmental, technological, economic, social, and regulatory factors.

Keywords: oily waste management, marine oil spill, multi-criteria decision making, oil spill response

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Authors: Mohammed Sghir Taleb

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Located at the northwest corner of the African continent between 21 ° and 36 ° north latitude and between the 1st and the 17th degree of west longitude, Morocco, with a total area of 715,000 km², enjoys a privileged position with a coastline of 3 446 km long opening to the Mediterranean and the Atlantic Ocean. Its privileged location with a double coastline and its diverse mountain with four major mountain ranges: the Rif, Middle Atlas, High Atlas, and Anti Atlas, with altitudes exceeding 2000 m in the Rif, 3000 m in the Middle Atlas, and 4000 m in the High Atlas. Morocco is characterized by an important forest genetic diversity represented by a rich and varied flora and many ecosystems: forest, preforest, presteppe, steppe, Sahara that spans a range of bioclimatic zones: arid, semiarid, subhumid, and humid. The vascular flora of Morocco is rich and highly diversified, with a very significant degree of endemism. Natural flora and ecosystems provide important services to populations represented by grazing, timber harvest, harvesting of medicinal and aromatic plants. This work will be focused on the Moroccan biodiversity and natural ecosystem services and on the interaction between local populations and ecosystems

Keywords: biodiversity, forest, ecosystem, services, Morocco

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Authors: Sanele Lionel Khanyile, Emmanuel Nahayo

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Geomagnetic jerks are jumps observed in the second derivative of the main magnetic field that occurs on annual to decadal timescales. Understanding these jerks is crucial as they provide valuable insights into the complex dynamics of the Earth’s outer liquid core. In this study, we investigate the occurrence of geomagnetic jerks in geomagnetic observatory data collected at southern African magnetic observatories, Hermanus (HER), Tsumeb (TSU), Hartebeesthoek (HBK) and Keetmanshoop (KMH) between 2017 and 2023. The observatory data was processed and analyzed by retaining quiet night-time data recorded during quiet geomagnetic activities with the help of Kp, Dst, and ring current RC indices. Results confirm the occurrence of the 2019-2020 geomagnetic jerk in the region and identify the recent 2021 jerk detected with V-shaped secular variation changes in X and Z components at all four observatories. The highest estimated 2021 jerk secular acceleration amplitudes in X and Z components were found at HBK, 12.7 nT/year² and 19. 1 nT/year², respectively. Notably, the global CHAOS-7 model aptly identifies this 2021 jerk in the Z component at all magnetic observatories in the region.

Keywords: geomagnetic jerks, secular variation, magnetic observatory data, South Atlantic Anomaly

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Authors: Khadijat Olabisi Abdulwahab, Mohammad Azad Malik, Paul O'Brien, Grigore Timco, Floriana Tuna

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The synthesis of spinel ferrite nanoparticles with a narrow size distribution is very crucial in their numerous applications including information storage, hyperthermia treatment, drug delivery, contrast agent in magnetic resonance imaging, catalysis, sensors, and environmental remediation. Ferrites have the general formula MFe₂O₄ (M = Fe, Co, Mn, Ni, Zn e.t.c) and possess remarkable electrical and magnetic properties which depend on the cations, method of preparation, size and their site occupancies. To the best of our knowledge, there are no reports on the use of a single source precursor to synthesise quaternary ferrite nanoparticles. Here in, we demonstrated the use of trimetallic iron pivalate cluster [CrCoFeO(O₂CᵗBu)₆(HO₂CᵗBu)₃] as a single source precursor to synthesise monodisperse cobalt chromium ferrite (FeCoCrO₄) nanoparticles by the hot injection thermolysis method. The precursor was thermolysed in oleylamine, oleic acid, with diphenyl ether as solvent at 260 °C. The effect of reaction time on the stoichiometry, phases or morphology of the nanoparticles was studied. The p-XRD patterns of the nanoparticles obtained after one hour was pure phase of cubic iron cobalt chromium ferrite (FeCoCrO₄). TEM showed that a more monodispersed spherical ferrite nanoparticles were obtained after one hour. Magnetic measurements revealed that the ferrite particles are superparamagnetic at room temperature. The nanoparticles were characterised by Powder X-ray Diffraction (p-XRD), Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS) and Super Conducting Quantum Interference Device (SQUID).

Keywords: cobalt chromium ferrite, colloidal, hot injection thermolysis, monodisperse, reaction time, single source precursor, quaternary ferrite nanoparticles

Procedia PDF Downloads 276

Authors: Khadijat O. Abdulwahab, Mohammad A. Malik, Paul O’Brien, Grigore A. Timco, Floriana Tuna

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The synthesis of spinel ferrite nanoparticles with a narrow size distribution is very crucial in their numerous applications including information storage, hyperthermia treatment, drug delivery, contrast agent in magnetic resonance imaging, catalysis, sensors, and environmental remediation. Ferrites have the general formula MFe2O4 (M = Fe, Co, Mn, Ni, Zn etc.) and possess remarkable electrical and magnetic properties which depend on the cations, method of preparation, size and their site occupancies. To the best of our knowledge, there are no reports on the use of a single source precursor to synthesise quaternary ferrite nanoparticles. Herein, we demonstrated the use of trimetallic iron pivalate cluster [CrCoFeO(O2CtBu)6(HO2CtBu)3] as a single source precursor to synthesise monodisperse cobalt chromium ferrite (FeCoCrO4) nanoparticles by the hot injection thermolysis method. The precursor was thermolysed in oleylamine, oleic acid, with diphenyl ether as solvent at its boiling point (260°C). The effect of concentration on the stoichiometry, phases or morphology of the nanoparticles was studied. The p-XRD patterns of the nanoparticles obtained at both concentrations were matched with cubic iron cobalt chromium ferrite (FeCoCrO4). TEM showed that a more monodispersed spherical ferrite nanoparticles of average diameter 4.0 ± 0.4 nm were obtained at higher precursor concentration. Magnetic measurements revealed that all the ferrite particles are superparamagnetic at room temperature. The nanoparticles were characterised by Powder X-ray Diffraction (p-XRD), Transmission Electron Microscopy (TEM), Inductively Coupled Plasma (ICP), Electron Probe Microanalysis (EPMA), Energy Dispersive Spectroscopy (EDS) and Super Conducting Quantum Interference Device (SQUID).

Keywords: quaternary ferrite nanoparticles, single source precursor, monodisperse, cobalt chromium ferrite, colloidal, hot injection thermolysis

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Authors: Dalrún Kaldakvísl Eygerðardóttir

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Shark fishing has been practiced for centuries in Iceland. The broad objective of this ongoing research is to study the history of shark fishing in Iceland from the high days of Icelandic shark fishing in the latter half of the 19th century to recent days. The main focus is on shark fishing in the 20th and 21st century. The research sheds light on how sharks have shaped the Icelandic society and how Icelandic society has shaped the lives of sharks, by providing historical context to the relationship between Icelanders and one of the top predators in the North Atlantic Ocean, the Greenland shark. It is important to explore this aspect of Icelandic history further, to enhance people´s understanding of the marine ecosystem from the context of the past and the current increasing concerns about the status of sharks worldwide. Next to nothing has been written about shark fishing in the 20th and 21st Iceland, which shows the importance of interviewing shark fishermen – most of whom are at an old age today. The main methodology used in the research is oral history. Oral history is a large and growing field of research within history, which is based on obtaining oral sources through interviews, analyzing them, and presenting them. The video-poster sheds light on how oral history provides useful historical information on shark fishing and shark conservation in Iceland.

Keywords: oral history, shark fishing in Iceland, 19. and 21. century, shark conservation, marine environmental history

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Authors: Regina Streltsov

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The Archipelago of the Azores in the NE Atlantic is a hot spot of marine biodiversity, both pelagic and demersal. Epinephelus marginatus is a solitary species commonly observed in these waters, with distinct territorial/residential behaviors from their post- larva and juvenile stages to the adult phase. Being commercially high valued species, about 13% of all groupers (Family Epinephelidae) face an increasing pressure that has produced known impacts in both the abundance and distribution of this group of fishes. Epinephelus marginatus is currently assessed by the IUCN as a vulnerable species. Dusky gropers inhabit rocky bottoms from shallow waters down to 200 m. Juveniles are usually found in shallow shoreline waters. Population dynamics of juveniles can lead to a better understanding of the competition for resources and predation and further conservation measures that must be taken upon dusky groupers. This study is carried out in rocky reefs from two sheltered bays on the south and north coast of the island in two different spots with four sampling sites in total. Using Transects individuals are counted at the peak of high tide and all abiotic factors are recorded. Our goal is to complete a statistically significant number of observations in order to detail these populations and to better understand their dynamics and dimension.

Keywords: Azores, dusky groupers, Epinephelus marginatus, population dynamics

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Authors: Nur Farah Ain Zainee, Ahmad Ismail, Nazlina Ibrahim, Asmida Ismail

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The study of genus Halimeda in Malaysia is in the early stage due to less specific study on its taxonomy. Most of the previous research tend to choose other genus such as Caulerpa and Gracilaria because of the potential of being utilized. The identification of Halimeda is complex by the high morphological variation within individual species due to different types of habitat and the changes in composition of seawater. The study was completed to study the diversity and distribution of Halimeda in Malaysia and to identify the morphological and anatomical differences between Halimeda species. The methods which have been used for this study are collection of Halimeda and seawater, preservation of specimen, identification of the specimen including the preparation of the temporary slide and decalcification of the calcium layer by using diluted hydrochloric acid. The specimen were processed in laboratory and kept as herbarium specimen in Algae Herbarium, Universiti Kebangsaan Malaysia. Environmental parameters were tested by using YSI multiparameter probe and the recorded data were temperature, salinity, pH and dissolved oxygen. The nutrient content of seawater such as nitrate and phosphate were analysed by using Hach kit model DR 2000. In the present study, out of 330 herbarium specimen, ten species were identified as Halimeda cuneata, H. discoidea, H. macroloba, H. macrophysa, H. opuntia, H. simulans, H. stuposa, H. taenicola, H. tuna and H. velasquezii. Of these, five species were new record to Malaysia. They are Halimeda cuneata, H. macrophysa, H. stuposa, H. taenicola and H. velasquezii. H. opuntia was found as the most abundance species with wide distribution in Malaysia coastal area. Meanwhile, from the study of their distribution, two localities in which Pulau Balak Balak, Kudat and Pulau Langkawi, Kedah, were noted having high number of Halimeda species. As a conclusion, this study has successfully identified ten species of Halimeda of Malaysia with full description of morphological characteristics that may assist further researcher to differentiate and identify Halimeda.

Keywords: Distribution, diversity, Halimeda, morphological, taxonomy

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Authors: Albert Chang, Duncan Webster

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Streptococcus equi subspecies zooepidemicus infections in humans can be contracted through contact with domestic animals or unpasteurized dairy products. Although infection in humans is rare, the course can be fulminant. We describe the case of a 75-year-old, immunocompetent male, who developed disseminated disease with bacteremia, native aortic valve endocarditis, suppurative pericarditis with cardiac tamponade, meningitis and bilateral endopthalmitis. Despite treatment with pericardial drain placement, intravenous ceftriaxone and rifampin the patient, unfortunately, did not survive. To date, reported cases of disseminated infection by S. zooepidemicus are few. Furthermore, with the review of the literature, this case demonstrates the broadest organ system involvement reported. Of interest, previous studies have suggested an affinity of this organism for certain organ systems and this case corroborates an emerging association of S. zooepidemicus with endopthalmitis. In addition, this is the second Canadian case of documented human infection with both cases being similar in clinical features, presentation, and geographical location. A discussion regarding previous S. zooepidemicus outbreaks and the potential for zoonotic outbreaks to occur is included. In short, this case report should serve to warn clinicians regarding complications and sites of haematogenous seeding in the setting of disseminated S. zooepidemicus infections.

Keywords: endopthalmitis, endocarditis, meningitis, Streptococcus equi subspecies zooepidemicus

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Authors: Deena Ramful-Baboolall, Eshana B. N. Bhatoo

Abstract:

Morinda citrifolia L., commonly known as noni fruit, is rich in phytochemicals. This study investigated the phytophenolics content and antioxidant activity of green, mature green and ripe noni fruits. The vitamin C content ranged from 41.12 ± 0.083 to 143.63 ± 0.146 mg / 100 ml in fresh noni fruits. Ripe fruits contained the highest level of ascorbic acid followed by mature green and green fruits (p < 0.05). The total phenol content ranged from 0.909 (green) to 2.305 (ripe) mg / g of FW whilst the total flavonoid content ranged from 1.054 (green) to 2.116 (ripe) mg/g of FW. The in vitro antioxidant activity of the Morinda citrifolia L. extracts was also analysed using FRAP and TEAC assays. The reducing power of the fruit extracts as assessed by the FRAP assay decreased in the following order: ripe > mature green > green (p < 0.05). The TEAC values ranged from 0.2631 to 0.8921 µmol / g FW, with extracts of fruits at the mature green stage having highest values followed by fruits at the ripe and green stage respectively (p < 0.05). High correlation values were obtained between total phenolics, total flavonoids, ascorbic acid contents and the TEAC and FRAP assays (r > 0.8). Noni fruit extracts (0.2 and 0.4 % m / m) were compared with BHT (0.02 % m / m) on their ability to protect canola oil and mayonnaise, prepared with canola oil, against lipid oxidation during storage at 40°C. Mature green and ripe extracts, at both concentrations, were more effective than BHT in retarding oxidation in both food systems as evidenced by peroxide value and conjugated diene value determinations. Noni extracts were also very effective in inhibiting lipid peroxidation in tuna fish homogenates, assessed using TBARS assay. Noni fruits at the mature green and ripe stages represent a potential source of natural antioxidants for use a food additive.

Keywords: antioxidant, canola oil, mayonnaise, Morinda citrifolia L. fruit extracts, total flavonoids, total phenol

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Authors: Mohammed Sghir Taleb

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Located at the northwest corner of the African continent between 21 ° and 36 ° north latitude and between the 1st and the 17th degree of west longitude, Morocco, with a total area of 715,000 km2, enjoys a privileged position with a coastline of 3 446 km long opening to the Mediterranean and the Atlantic Ocean. Its privileged location with a double coastline and its diverse mountain with four major mountain ranges: the Rif, Middle Atlas, High Atlas and Anti Atlas, with altitudes exceeding 2000 m in the Rif, 3000 m in the Middle Atlas and 4000 m in the High Atlas. Morocco is characterized by an important forest genetic diversity represented by a rich and varied flora and many ecosystems: forest, preforest, presteppe, steppe, Sahara that spans a range of bioclimatic zones: arid, semiarid, subhumid, and humid. The vascular flora of Morocco is rich and highly diversified, with a very significant degree of endemism. Natural flora and ecosystems provide important services to populations represented by grazing, timber harvest, harvesting of medicinal and aromatic plants. This work will be focused on the Moroccan biodiversity and natural ecosystem services and on the interaction between local populations and ecosystems and on the strategies developed by Morocco for restoring and conserving biodiversity and ecosystem services.

Keywords: morocco, biodiversity, forest ecosystems, local population

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Authors: Ime R. Udotong, Justina I. R. Udotong, Ofonime U. M. John

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Ibeno, Nigeria hosts the operational base of Mobil Producing Nigeria Unlimited (MPNU), a subsidiary of ExxonMobil and the current highest oil and condensate producer in Nigeria. Besides MPNU, other oil companies operate onshore, on the continental shelf and deep offshore of the Atlantic Ocean in Ibeno, Nigeria. This study was designed to delineate oil polluted sites in Ibeno, Nigeria using geophysical methods of electrical resistivity (ER) and ground penetrating radar (GPR). Results obtained revealed that there have been hydrocarbon contaminations of this environment by past crude oil spills as observed from high resistivity values and GPR profiles which clearly show the distribution, thickness and lateral extent of hydrocarbon contamination as represented on the radargram reflector tones. Contaminations were of varying degrees, ranging from slight to high, indicating levels of substantial attenuation of crude oil contamination over time. Moreover, the display of relatively lower resistivities of locations outside the impacted areas compared to resistivity values within the impacted areas and the 3-D Cartesian images of oil contaminant plume depicted by red, light brown and magenta for high, low and very low oil impacted areas, respectively confirmed significant recent pollution of the study area with crude oil.

Keywords: electrical resistivity, geophysical investigations, ground penetrating radar, oil-polluted sites

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Authors: Olanrewaju B. Lasisi

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The position of Ijebu-Ode, the historical capital of the Ijebu Kingdom, at the center of gravity of Ijebu land is enclosed by the 180-km-long earthwork and suggests a centrally controlled project. This paper reflects on the first stratigraphic drawing of the banks and ditches of this earthwork, and place its construction mechanism in a chronological framework. Nine radiocarbon dates obtained at the site suggest that the earthwork was built in the late 14th or early 15th century. This suggests a relationship with the Ijebu Kingdom, which pre-existed the opening of the Atlantic trade but first became visible only in the Portuguese records in the 1480s. In June 2017, more earthworks were found but within the core of Ijebu Land. This most recent finding points to an extension of territory from the center to the outlying villages. One central question about this discovery of monumental architectures that was functional around the 14th century or before is in its mode of construction. Apparently, iron tools must have been used in the construction of ‘a 20m deep ditch that runs 180km in circumference.’ Thus, the discovery of iron-working sites around the vicinity of the earthwork is a pointer to this building process that is up till now shrouded in mystery. By comparing the chronology of Ijebu earthworks with the evidence of Iron working in south western Nigeria around the first half of the first millennium AD, it can be thought that the rise in polity triggered the knowledge of metallurgy in the region.

Keywords: archaeology, earthworks, Ijebu, metallurgy

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Authors: Sukovatov K.Yu., Bezuglova N.N.

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Winter precipitation variability over the Altai Krai was investigated by retrieving temporal patterns. The spectral singular analysis was used to describe the variance distribution and to reduce the precipitation data into a few components (modes). The associated time series were related to large-scale atmospheric and oceanic circulation indices by using lag cross-correlation and wavelet-coherence analysis. GPCC monthly precipitation data for rectangular field limited by 50-550N, 77-880E and monthly climatological circulation index data for the cold season were used to perform SSA decomposition and retrieve statistics for analyzed parameters on the time period 1951-2017. Interannual variability of winter precipitation over the Altai Krai are mostly caused by three natural factors: intensity variations of momentum exchange between mid and polar latitudes over the North Atlantic (explained variance 11.4%); wind speed variations in equatorial stratosphere (quasi-biennial oscillation, explained variance 15.3%); and surface temperature variations for equatorial Pacific sea (ENSO, explained variance 2.8%). It is concluded that under the current climate conditions (Arctic amplification and increasing frequency of meridional processes in mid-latitudes) the second and the third factors are giving more significant contribution into explained variance of interannual variability for cold season atmospheric precipitation over the Altai Krai than the first factor.

Keywords: interannual variability, winter precipitation, Altai Krai, wavelet-coherence

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Authors: Tyrus C. Torres, Michael Harris

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In a coastal town of Ecuador, the role of women is commonly defined as an ama de casa, a woman who works in the house, raises children, and contributes to the community. This project, under the guidance of Dr. Michael Harris from the Florida Atlantic University, seeks to understand how the role of an ama de casa provides a secure environment for men and women, coexists with economic and environmental constraints that explain the origins of how this environment has been formed. The coastal community aspects of familia (family), trabajo (work), relación (relationships), machismo (masculinity), feminista (femininity), and the culture of Ecuador define the ways of life in a coastal setting. This ethnographic research project included the following methodologies: environment mapping, conducting interviews, surveys, participant observation, direct and indirect observations, and integration into daily life. Immersion into the daily life and building relationships with the local people allowed the documentation of intricacies of both the cultural and social spheres. The findings of this research offer insight on how culture, economics, and environment can form female and male agency. Our investigation shows that occupations such as fishermen, laborers, ama de casas, and even students utilize occupational routes to create social agency in the face of economic and environmental constraints in Ecuador.

Keywords: Ecuador, ethnography, gender division of labor, gender roles

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Authors: Ime R. Udotong, Justina I. R. Udotong, Ofonime U. M. John

Abstract:

Mobil Producing Nigeria Unlimited (MPNU), a subsidiary of ExxonMobil and the highest crude oil & condensate producer in Nigeria has its operational base and an oil terminal, the Qua Iboe terminal (QIT) located at Ibeno, Nigeria. Other oil companies like Network Exploration and Production Nigeria Ltd, Frontier Oil Ltd; Shell Petroleum Development Company Ltd; Elf Petroleum Nigeria Ltd and Nigerian Agip Energy, a subsidiary of the Italian ENI E&P operate onshore, on the continental shelf and in deep offshore of the Atlantic Ocean, respectively with the coastal waters of Ibeno, Nigeria as the nearest shoreline. This study was designed to delineate the oil-polluted sites in Ibeno, Nigeria using microbiological and physico-chemical characterization of soils, sediments and ground and surface water samples from the study area. Results obtained revealed that there have been significant recent hydrocarbon inputs into this environment as observed from the high counts of hydrocarbonoclastic microorganisms in excess of 1% at all the stations sampled. Moreover, high concentrations of THC, BTEX and heavy metals contents in all the samples analyzed corroborate the high recent crude oil input into the study area. The results also showed that the pollution of the different environmental media sampled were of varying degrees, following the trend: Ground water > surface water > sediments > soils.

Keywords: microbiological characterization, oil-polluted sites, physico-chemical analyses, total hydrocarbon content

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Authors: Marisa Galiza Filipe

Abstract:

In 1942, at the height of the Second World War, Roosevelt and Churchill planned to occupy the Azores to establish air and naval bases. The islands' privileged position in the middle of the Atlantic made them a strategic location for both the Axis and the Allies. For the Germans, the occupation of the island was also a strategic place to launch an attack on the United States of America, and for the British and Americans, the islands were the perfect spot to counterattack the German sinking of British boats and submarines. Salazar avoided the concession of the islands until 1943, claiming, on the one hand, the policy of neutrality, a decision made in agreement with England, and on the other hand, the reaffirmation of Portuguese sovereignty over the territory. Aware of the constant changes and supported by a network of informers on the islands, the German and British spies played a crucial role in the negotiations between Portugal and the Allies and the ceding of the bases by Salazar, which prevented their forced occupation. The espionage caused several diplomatic tensions, and the large number of German spies denounced by the British, operating on the islands under the watchful eye of the PVDE and Salazar, weakened the Portuguese-British alliance. Using primary source documents in the Ministério dos Negócios Estrangeiros (MNE) archives, this paper introduces the spies that operated on the islands, their missions and motives, organizations, and modus operandi. As a chess game, any move was careful thinking and the spies were valuable assets to control and use information that could lead to the occupation of the islands and, ultimately, change the tide of the war.

Keywords: espionage, Azores, WWI, neutrality

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