A novel improved elephant herding optimization for path planning of a mobile robot

Swarm intelligence algorithms have been in recent years one of the most used tools for planning the trajectory of a mobile robot. Researchers are applying those algorithms to find the optimal path, which reduces the time required to perform a task by the mobile robot. In this paper, we propose a new method based on the grey wolf optimizer algorithm (GWO) and the improved elephant herding optimization algorithm (IEHO) for planning the optimal trajectory of a mobile robot. The proposed solution consists of developing an IEHO algorithm by improving the basic EHO algorithm and then hybridizing it with the GWO algorithm to take advantage of the exploration and exploitation capabilities of both algorithms. The comparison of the IEHO-GWO hybrid proposed in this work with the GWO, EHO, and cuckoo-search (CS) algorithms via simulation shows its effectiveness in finding an optimal trajectory by avoiding obstacles around the mobile robot

Social Inheritance Can Explain the Structure of Animal Social Networks

The social network structure of animal populations has major implications to survival, reproductive success, sexual selection, and pathogen transmission. Recent studies showed in various species that the structure of social networks and individuals’ positions in it are influenced by individual traits such as sex, age, and social rank, and can be heritable between generations. But as of yet, no general theory of social network structure exists that can explain the diversity of social networks observed in nature, and serve as a null model for detecting species and population-specific factors. Here we propose such a general model of social network structure. We consider the emergence of network structure as a result of two types of social bond formation: via social inheritance, in which newborns are likely to bond with maternal contacts, and via forming bonds randomly. We compare model output to data from several species, showing that it can generate networks with properties such as those observed in real social systems. Our model demonstrates that some of the observed properties of social networks, such as heritability of network position or assortative associations, can be understood as a consequence of social inheritance. Our results highlight the need to consider the dynamic processes that generate social structure in order to explain patterns of variation in social networks

Breakdown of keratin-laden biomass waste by the thermophilic bacterium Fervidobacterium pennivorans strain T

Developing a more sustainable agro-industry has become a necessity in light of the current environmental crisis. Biocatalysts are already adopted in many industrial applications and have quickly optimized, and in some cases replaced, existing biochemical reactions within the modern agro-industry. Extremozymes, in particular, are valuable tools for processes requiring harsh industrial conditions where, for example, increased temperature may be beneficial for the bioavailability and solubility of organic compounds as well as for improvement in degradation of substrates. In this regard, alternatives to landfill disposal or incineration of keratinous materials such as feathers, wool, hides, hair etc. are emerging and efforts in exploiting thermo-stable keratinolytic biocatalysts have been attempted. Nonetheless, keratin degradation remains a complex process poorly understood and thus limiting the current toolbox of useful enzymes and organisms needed to meet all demands. In this study, a newly isolated strain of an anaerobic, thermophilic microorganism belonging to the Thermotogae phylum, Fervidobacterium pennivorans strain T, was assessed for its capability of degrading native chicken feathers. By following a multiomics approach, its proteolytic system was explored in the attempt to isolate new keratinase candidates. First, the physiology of F. pennivorans strain T was further investigated in batch cultures and the first growth curve of an organism of this species was described, showing a generation time of 150 minutes and a long stationary phase. Then, the complete genome of the organism was sequenced and analysed, revealing interesting molecular features, such as inverted genomic blocks, when compared to its most closely related organisms: F. pennivorans DSM9078T and F. islandicum AW-1. The strain T genome was slightly shorter (2002515 base pair) and had ANI values of 97.65 % and 80.90% to the compared organisms, respectively, but the same number of predicted protease-encoding genes (55) were found by gene mining analysis. Next, feather degradation by the organism was up-scaled using a bioreactor to further evaluate its potential in industrial applications and cells were sampled for transcriptomics purposes. F. pennivorans strain T performed mediocrely in the fermenter, but RNA extraction was, however, not successful. From secretomics analysis of growing cultures, an extracellular serine protease named Peg_1025 was identified, showing high sequence conservation with the subtilisin type proteases, especially with subtilisin Ak1 from Geobacillus stearothermophilus strain AK1. By multiple sequencing alignment, the catalytic triad His, Asp, Ser, as well as a signal peptide and a propeptide domain were predicted. Three dimensional structural modelling using subtilisin Ak1 as template, showed Peg_1025 to possess several insertions of unknown functions compared to subtilisin Ak1, only one conserved Ca2+ binding site as well as lack of a disulphide bond in the active cleft. Nonetheless, important structural motifs remained conserved. The enzyme was successfully expressed in E. coli using N- and C-terminal His-tag and soluble proteins were active at 70°C in proteolytic activity assays that used casein as substrate. Phylogenetic analyses revealed that Peg_1025 belongs to a distinct clade of Thermotogae peptidases separated from fervidolysin and Ak1, and as such, it represents the first characterized member of this phylogenetic group. Although the specific role of the serine protease in feather degradation remains unclear, the general results from this study confirm that F. pennivorans strain T possesses a complex machinery with keratinolytic power. The biology of this extremophile remains an intriguing field of exploration, further encouraged by its biotechnological potential that is still left to unfold.Master's Thesis in BiologyBIO399MAMN-BI

Uncovering Relationships between Sustainable Business Practice Bundles, Organizational Culture, and Performance

abstract: Corporations work to reduce their negative impacts on the environment and society by adopting Sustainable business (SB) practices. Businesses create competitive advantages via practices such as waste minimization, green product design, compliance with regulations, and stakeholder relations. Normative models indicate that businesses should adopt similar sustainability practices, however, contingency theory suggests that effectiveness of practices depends on the context of the business. The literature highlights the importance of organizational culture as a moderating variable between SB practices and outcomes, however this link has not been empirically examined. This thesis presents the development and testing of a theoretical model, using configuration theory, that links SB practices, organizational culture, and financial performance. Published frameworks were utilized to identify SB practices in use, and the Competing Values Framework (CVF) to identify dimensions of culture. Data from 1021 Corporate Sustainability Reports from 212 companies worldwide was collected for computerized text analysis, which provided a measure of the occurrence of a specific SB practice and the four dimensions of the CVF. Hypotheses were analyzed using cluster, crosstab, and t-test statistical methods. The findings contribute significant insights to the Business and Sustainability field. Firstly, clustering of SB practice bundles identified organizations at various levels of SB practice awareness. The spectrum runs from a compliance level of awareness, to a set of organizations aware of the importance of culture change for sustainability. Top performing clusters demonstrated different priorities with regards to SB practices; these were in many cases, related to contextual factors, such as location or sector. This implies that these organizations undertook varying sustainability strategies, but all arrived at some successful level of sustainability. Another key finding was the association between the highest performing SB practice clusters and a culture dominated by Adhocracy values, corroborating theories presented in the literature, but were not empirically tested before. The results of this research offer insights into the use of text analysis to study SB practices and organizational culture. Further, this study presents a novel attempt at empirically testing the relationship between SB practices and culture, and tying this to financial performance. The goal is that this work serves as an initial step in redefining the way in which businesses adopt SB practices. A transformation of SB practice adoption will lead to major improvements in sustainability strategies, and subsequently drive change for improved corporate sustainability.Dissertation/ThesisDoctoral Dissertation Sustainability 201

Evolutionary Computation 2020

Intelligent optimization is based on the mechanism of computational intelligence to refine a suitable feature model, design an effective optimization algorithm, and then to obtain an optimal or satisfactory solution to a complex problem. Intelligent algorithms are key tools to ensure global optimization quality, fast optimization efficiency and robust optimization performance. Intelligent optimization algorithms have been studied by many researchers, leading to improvements in the performance of algorithms such as the evolutionary algorithm, whale optimization algorithm, differential evolution algorithm, and particle swarm optimization. Studies in this arena have also resulted in breakthroughs in solving complex problems including the green shop scheduling problem, the severe nonlinear problem in one-dimensional geodesic electromagnetic inversion, error and bug finding problem in software, the 0-1 backpack problem, traveler problem, and logistics distribution center siting problem. The editors are confident that this book can open a new avenue for further improvement and discoveries in the area of intelligent algorithms. The book is a valuable resource for researchers interested in understanding the principles and design of intelligent algorithms

A Topic Modeling approach for Code Clone Detection

In this thesis work, the potential benefits of Latent Dirichlet Allocation (LDA) as a technique for code clone detection has been described. The objective is to propose a language-independent, effective, and scalable approach for identifying similar code fragments in relatively large software systems. The main assumption is that the latent topic structure of software artifacts gives an indication of the presence of code clones. It can be hypothesized that artifacts with similar topic distributions contain duplicated code fragments and to prove this hypothesis, an experimental investigation using multiple datasets from various application domains were conducted. In addition, CloneTM, an LDA-based working prototype for code clone detection was developed. Results showed that, if calibrated properly, topic modeling can deliver a satisfactory performance in capturing different types of code clones, showing particularity good performance in detecting Type III clones. CloneTM also achieved levels of performance comparable to already existing practical tools that adopt different clone detection strategies

Ancient genetic landscape of archaeological human remains from Panama, South America and Oceania described through STR genotype frequencies and mitochondrial DNA sequences

The settlements of the Americas and Oceania are particularly fascinating topics. On the one side is the settlements of Australia and New Guinea (30,000 – 50,000 years ago) were the scenarios of one of the earliest migration events carried out by modern humans after left Africa, while Polynesia around 3,000 years ago was the stage of the last major colonization event. Regarding America, despite broad agreement that the Americas were initially populated via Bering, during the Upper Pleistocene 14,600 years ago, it is still a topic controversial, mysterious, shifting, and continuously conflictive as the Ice Age archaeology of the Americas, since, the dates and routes of the peopling of the Americas remain unresolved. Thus, ancient DNA studies on archaeological human remains from Oceania and America are useful to explore the genetic history of these human groups. Given that Near Oceania colonization was the endpoint of one of the earliest Out-of-Africa migrations about 50,000 years ago, and the islands of East Polynesia were the last region of the world to be colonized by humans approximately 1,000 years ago. Whilst, in America, one of the most contentious issues is whether the settlement occurred by means of a single migration or migration streams of migrations from Siberia. Because the gene flow is an important mechanism that contributes to genetic diversity among populations, the presence or absence of certain haplogroups changes the distribution of genetic diversity within populations. Thus, to understand the population dynamics of Oceanians and American peoples before European contact, it was necessary to describe the grade of nuclear and mitochondrial DNA genetic variation. One hundred twenty-five paleo-anthropological remains were analysed via genotyping of six short tandem repeats (STR) markers (nuclear DNA). Moreover, the genetic variation, inferences of demographic histories and clustering trends of these samples were evaluated through the hypervariable segment I (HVSI) of mitochondrial DNA (mtDNA). 35% of the archaeological remains analysed were genotyped successfully. Mitochondrial genetic diversity observed in Oceanian, South American and Panamanian samples reflected the genetic drift effects on these individuals through the founder effect, which happened during Upper Pleistocene when the modern humans reached these regions for the first time. The inferences of historical demographic patterns suggest that ancient individuals from Oceania went through population expansion about 37,972 years ago, which is consistent with the initial colonization of Melanesia. Whilst, ancient individuals from South America and Panama went through population expansions about 14,150 and 9,468 years ago, respectively, correspond to the initial settlement of America during the Upper Pleistocene. The clustering patterns showed that ancient individuals from Bismark Archipelago and Papua New Guinea, and the ancient individuals from New Zealand and Samoa exhibited greater affinity with each other. The cluster branch of America exhibited genetic affinities between ancient Panamanian and South American samples, probably resulted from a migratory event, along the Pacific North Coast, from North America to South America that took place between the Middle and the Upper Holocene.2021-12-2

Socioecology, Acoustic Communication and Demography of Asian Elephants in Sri Lanka

SOCIOECOLOGY, ACOUSTIC COMMUNICATION AND DEMOGRAPHY OF ASIAN ELEPHANTS IN SRI LANKA Shermin de Silva (Author) Dorothy L. Cheney (Supervisor) Comparison of behavior across species brings to light the underlying social and ecological factors that have shaped social organization and communication. Elephantids, the only living members of the Proboscidean clade are cognitively sophisticated, long-lived, putatively social mammals. I examine how vocal communication and social organization in Asian elephants (Elephas maximus) compare to African savannah elephants (Loxodonta africana), as well as basic demographic and conservation issues concerning Asian elephants. The first chapter defines fourteen distinct acoustic signals based on their acoustic features, and describes the contexts in which they occur. Most vocalizations are employed in contexts of movement, and some vocalizations are used primarily during movement or non-aggressive social interactions. This suggests that elephants actively seek out association with particular individuals. The second chapter tests the hypothesis that associations among adult female Asian elephants are governed by resourced availability, and describes the temporal structure and strength of bonds. This study population demonstrates fission-fusion social dynamics in which individuals change companions over short time scales, influenced by rainfall, but maintain stable relationships over long time scales. In the third chapter I test the hypothesis that associations are purely the consequence of the spatial distribution of resources, rather than social preference, using a modeling approach based on the spatio-temporal coordinates of individuals. In all seasons, individuals appear to move in a coordinated manner, supporting the interpretation that observed associations reflect true social preference. At the same time, resource distributions do influence the size of social units, and their movements. In the fourth chapter I review the most recent demographic studies of elephant populations in Asia as well as Africa, and highlight the lack of data for much of Asia. I outline methods based on individual identification that may be used to address this challenge to conservation and management. I apply these methods to offer demographic estimates for the study site, and examine what constitutes good practice, in the fifth chapter