75 research outputs found

    Recent African derivation of Chrysomya putoria from C. chloropyga and mitochondrial DNA paraphyly of cytochrome oxidase subunit one in blowflies of forensic importance

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    Chrysomya chloropyga (Wiedemann) and C. putoria (Wiedemann) (Diptera: Calliphoridae) are closely related Afrotropical blowflies that breed in carrion and latrines, reaching high density in association with humans and spreading to other continents. In some cases of human death, Chyrsomya specimens provide forensic clues. Because the immature stages of such flies are often difficult to identify taxonomically, it is useful to develop DNA-based tests for specimen identification. Therefore we attempted to distinguish between C. chloropyga and C. putoria using mitochondrial DNA (mtDNA) sequence data from a 593-bp region of the gene for cytochrome oxidase subunit one (COI). Twelve specimens from each species yielded a total of five haplotypes, none being unique to C. putoria. Therefore it was not possible to distinguish between the two species using this locus. Maximum parsimony analysis indicated paraphyletic C. chloropyga mtDNA with C. putoria nested therein. Based on these and previously published data, we infer that C. putoria diverged very recently from C. chloropyga

    Oral mucosal lesions and their association with sociodemographic, behavioral, and health status factors

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    The aim of this study was to evaluate the frequency of oral mucosal lesions and their associations with sociodemographic, health, and behavioral factors in a southern Brazilian population. Information was collected from participants (n = 801) using a structured questionnaire during an oral cancer screening campaign held at an agribusiness show in southern Brazil in 2009. Data were described using frequency distributions or means and standard deviations. Associations between independent variables and outcomes were assessed using the Chi-squared test. A total of 465 lesions were detected (actinic cheilitis: n = 204, 25.5%; candidiasis: n = 50, 6.2%; fibrous inflammatory hyperplasia: n = 42, 5.2%; ulceration, n = 33, 4.1%; hemangioma: n = 14, 1.7%; leukoplakia: n = 11, 1.4%). Candidiasis, actinic cheilitis, and fibrous inflammatory hyperplasia were associated significantly with literacy. Actinic cheilitis was also associated significantly with sun exposure and hat use, and leukoplakia was associated with smoking. The high frequency of oral mucosal lesions observed highlights the importance of education about risk factors. Additionally, training of health professionals, mainly those from public health services, in the use of preventive and community education strategies is needed

    The uses of Chrysomya megacephala (Fabricius, 1794)(Diptera: Calliphoridae) in forensic entomology:

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    Chrysomya megacephala (Fabricius, 1794) occurs on every continent and is closely associated with carrion and decaying material in human environments. Its abilities to find dead bodies and carry pathogens give it a prominence in human affairs that may involve prosecution or litigation, and therefore forensic entomologists. The identification, geographical distribution and biology of the species are reviewed to provide a background for approaches that four branches of forensic entomology (urban, stored-product, medico-criminal and environmental) might take to investigations involving this fly

    The authority of pleasure

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    The aim of the paper is to reassess the prospects of a widely neglected affective conception of the aesthetic evaluation and appreciation of art. On the proposed picture, the aesthetic evaluation and appreciation of art are non-contingently constituted by a particular kind of pleasure. Artworks that are valuable qua artworks merit, deserve, and call for a certain pleasure, the same pleasure that reveals (or at least purports to reveal) them to be valuable in the way that they are, and constitutes their aesthetic evaluation and appreciation. This is why and how art is non-contingently related to pleasure. Call this, the Affective View. While I don’t advance conclusive arguments for the Affective View in this paper, I aim to reassess its prospects by (1) undermining central objections against it, (2) dissociating it from hedonism about the value of artworks (the view that this value is grounded in, and explained by, its possessors’ power to please), and (3) introducing some observations on the practice of art in support of it. Given that the objections I discuss miss their target, and given the observations in support of it, I conclude that the Affective View is worth serious reconsideration

    Towards Privacy Preserving Consensus Control in Multi-Agent Cyber-Physical Systems Subject to Cyber Attacks

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    Multi-agent systems (MAS) require sharing their information with their neighboring agents to reach a consensus in a distributed manner. In this paper, a transformation-based consensus control methodology is developed and implemented that can be utilized to reach a consensus among agents in a distributed manner without revealing their true information to their neighboring agents. The proposed methodology protects agents privacy against eavesdropper adversaries and malicious agents capable of intercepting and accessing the agents' exchanged data. A unique isometric isomorphism is employed for each agent to map the true value of exchanged sensor measurements and state estimates. By leveraging the property of isometric isomorphism in preserving norms, it is shown that reaching a consensus among agents is equivalent to that can be accomplished by the transformed agents dynamics. Numerical case studies are provided to illustrate the effectiveness of the proposed and developed methodology in preserving agents' privacy while ensuring that the MAS accomplish consensus requirements despite the presence of cyber attacks.North Atlantic Treaty Organization; Qatar Foundation; Qatar National Research Fund; Natural Sciences and Engineering Research Council of Canada; Ministre de la Dfense NationaleScopu

    Undetectable Cyber Attacks on Communication Links in Multi-Agent Cyber-Physical Systems

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    The objective in this paper is to study and develop conditions for a network of multi-agent cyber-physical systems (MAS) where a malicious adversary can utilize vulnerabilities in order to ensure and maintain cyber attacks undetectable. We classify these cyber attacks as undetectable in the sense that their impact cannot be observed in the generated residuals. It is shown if an agent that is the root of a rooted spanning tree in the MAS graph is under a cyber attack, the attack is undetectable by the entire network. Next we investigate if a non-root agent is compromised, then under certain conditions cyber attacks can become detectable. Moreover, a novel cyber attack that is designated as quasi-covert cyber attack is introduced that can be used to eliminate detectable impacts of cyber attacks to the entire network and maintain these attacks as undetected. Finally, an event-triggered based detector is proposed that can be used to detect the quasi-covert cyber attacks. Numerical simulations are provided to illustrate the effectiveness and capabilities of our proposed methodologies.North Atlantic Treaty Organization; Qatar Foundation; Qatar National Research Fund; Natural Sciences and Engineering Research Council of Canada; Ministre de la Dfense NationaleScopu
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