4,088 research outputs found
Where AES is for Internet, SIMON could be for IoT
No full textAbstractWith the upcoming era of Internet of Things and the Pervasive Computing, there is a need to develop block ciphers with tight constraints such as area, power, memory, performance, throughput and others. These are so called the lightweight block ciphers which are specifically intended for resource constrained platforms. Lined up in the line is SIMON, a light weight block cipher proposed by NSA after the prompting from the U.S. Government in the year 2013 along with SPECK lightweight block cipher. SIMON implementation on hardware has excellent results in terms of area and has been found to be a very strong alternative to the existing AES. This paper involves the basic design considerations, round functions, key schedule and parameters of SIMON and also we can look forward into the implementations of SIMON in hardware comparing with the existing AES standard. This paper also focuses on the analysis in terms of area, power and delay of the SIMON 64/128 configuration in Cadence Synthesis RTL Compiler using the CMOS 180 nm and 90 nm technology libraries
Hydroxypyridine/pyridone interconversions within ruthenium complexes and their application in the catalytic hydrogenation of CO<sub>2</sub>
No full textReaction of a new ligand 6-DiPPon (6-diisopropylphosphino-2-pyridone) with 0.5 equiv of [RuCl2(p-cymene)]2 resulted in the formation of a mixture of [RuCl2(p-cymene)(κ1-P-6-DiPPon)]2 (1) and [RuCl(p-cymene)(κ2-P,N-6-DiPPin)]Cl ([2]Cl) (where 6-DiPPin = 6-diisopropylphosphino-2-hydroxypyridine). The ratio between the two products can be controlled by the nature of the solvent. The similar reaction between 6-DiPPon and [RuCl2(p-cymene)]2 in the presence of AgOTf and Na[BArF24] (where BArF24 = [{3,5-(CF3)2C6H3}4B]−) resulted in the formation of the complexes [RuCl(p-cymene)(κ2-P,N-6-DiPPin)]OTf, ([2]OTf) and [RuCl(p-cymene)(κ2-P,N-6-DiPPin)]BArF24 ([2]BArF24), respectively. Reactions between complex [2]Cl, [2]OTf, or [2]BArF24 and a base (either DBU or NaOMe) resulted in the deprotonation of the hydroxyl functional group to form a novel neutral orange-colored dearomatized complex, 3. The identity of complex 3 was confirmed as [RuCl(p-cymene)(κ2-P,N-6-DiPPon*)], where 6-DiPPon* is the anionic species (6-diisopropylphosphino-2-oxo-pyridinide), which contains the deprotonated moiety. The new 6-DiPPon ligand and its corresponding air stable half-sandwich derivative ruthenium complexes 1, [2]OTf, [2]BArF24, and 3 were all isolated in good yields and fully characterized by spectroscopic and analytical methods. The interconversions between the neutral and anionic forms of the ligands 6-DiPPon, 6-DiPPin, and 6-DiPPon* offer the potential for novel secondary sphere interactions and proton shuttling reactivity. The consequences for this have been explored in the activation of H2 and the subsequent catalytic hydrogenations of CO2 into formate salts in the presence of a base.</p
A rare mutation in an infant-derived HIV-1 envelope glycoprotein alters interprotomer stability and susceptibility to broadly neutralizing antibodies targeting the trimer apex
No full textThe envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) is the sole target of broadly neutralizing antibodies (bnAbs). Several mechanisms, such as the acquisition of mutations, variability of the loop length, and alterations in the glycan pattern, are employed by the virus to shield neutralizing epitopes on Env to sustain survival and infectivity within the host. The identification of mutations that lead to viral evasion of the host immune response is essential for the optimization and engineering of Env-based trimeric immunogens. Here, we report a rare leucine-to-phenylalanine escape mutation (L184F) at the base of hypervariable loop 2 (population frequency of 0.0045%) in a 9-month-old perinatally HIV-1-infected infant broad neutralizer. The L184F mutation altered the trimer conformation by modulating intramolecular interactions stabilizing the trimer apex and led to viral escape from autologous plasma bnAbs and known N160 glycan-targeted bnAbs. The L184F amino acid change led to the acquisition of a relatively open trimeric conformation, often associated with tier 1 HIV-1 isolates and increased susceptibility to neutralization by polyclonal plasma antibodies of weak neutralizers. While there was no impact of the L184F mutation on free virus transmission, a reduction in cell-to-cell transmission was observed. In conclusion, we report a naturally selected viral mutation, L184F, that influenced a change in the conformation of the Env trimer apex as a mechanism of escape from contemporaneous plasma V2 apex-targeted nAbs. Further studies should be undertaken to define viral mutations acquired during natural infection, to escape selection pressure exerted by bnAbs, to inform vaccine design and bnAb-based therapeutic strategies. IMPORTANCE The design of HIV-1 envelope-based immunogens capable of eliciting broadly neutralizing antibodies (bnAbs) is currently under active research. Some of the most potent bnAbs target the quaternary epitope at the V2 apex of the HIV-1 Env trimer. By studying naturally circulating viruses from a perinatally HIV-1-infected infant with plasma neutralizing antibodies targeted to the V2 apex, we identified a rare leucine-to-phenylalanine substitution, in two out of six functional viral clones, that destabilized the trimer apex. This single-amino-acid alteration impaired the interprotomeric interactions that stabilize the trimer apex, resulting in an open trimer conformation and escape from broadly neutralizing autologous plasma antibodies and known V2 apex-directed bnAbs, thereby favoring viral evasion of the early bnAb response of the infected host. Defining the mechanisms by which naturally occurring viral mutations influence the sensitivity of HIV-1 to bnAbs will provide information for the development of vaccines and bnAbs as anti-HIV-1 reagents.</p
Parameter estimation in oceanographic flows and computation of flows driven by density gradient
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Taxonomic revision, molecular phylogeny and zoogeography of the huntsman spider genus Eusparassus (Araneae: Sparassidae)
No full textThe spider genus Eusparassus Simon, 1903 (Araneae: Sparassidae: Eusparassinae; stone huntsman spider) is revised worldwide to include 30 valid species distributed exclusively in Africa and Eurasia. The type species E. dufouri Simon, 1932 is redescribed and a neotype is designated from Portugal. An extended diagnosis for the genus is presented. Eight new species are described: Eusparassus arabicus Moradmand, 2013 (male, female) from Arabian Peninsula, E. educatus Moradmand, 2013 (male, female) from Namibia, E. reverentia Moradmand, 2013 (male, female) from Burkina Faso and Nigeria, E. jaegeri Moradmand, 2013 (male, female) from South Africa and Botswana, E. jocquei Moradmand, 2013 (male, female) from Zimbabwe, E. borakalalo Moradmand, 2013 (female) from South Africa, E. schoemanae Moradmand, 2013 (male, female) from South Africa and Namibia and E. mesopotamicus Moradmand and Jäger, 2012 (male and female) from Iraq, Iran and Turkey. 22 species are re-described six of them are transferred from the genus Olios Walckenaer, 1837. Six species-groups are proposed: the dufouri-group [8 species: E. dufouri, E. levantinus Urones, 2006, E. barbarus (Lucas, 1846), E. atlanticus Simon, 1909, E. syrticus Simon, 1909, E. oraniensis (Lucas, 1846), E. letourneuxi (Simon, 1874), E. fritschi (Koch, 1873); Iberian Peninsula to parts of north-western Africa], walckenaeri-group [3 species: E. walckenaeri (Audouin, 1826), E. laevatus (Simon, 1897), E. arabicus; eastern Mediterranean to Arabia and parts of north-eastern Africa], doriae-group [7 species: E. doriae (Simon, 1874), E. kronebergi Denis, 1958, E. maynardi (Pocock, 1901), E. potanini (Simon, 1895), E. fuscimanus Denis, 1958, E. oculatus (Kroneberg, 1846) and E. mesopotamicus; Middle East to Central and South Asia], vestigator-group (3 species: E. vestigator (Simon, 1897), E. reverentia, E. pearsoni (Pocock, 1901); central to eastern Africa and an isolated area in NW India], jaegeri-group [4 species: E. jaegeri, E. jocquei, E. borakalalo, E. schoemanae; southern and south-eastern Africa], tuckeri-group [2 species: E. tuckeri (Lawrence, 1927), E. educatus; south-western Africa). Two species, E. pontii Caporiacco, 1935 and E. xerxes (Pocock, 1901) cannot be placed in any of the above groups. Two species are transferred from Eusparassus to Olios: O. flavovittatus (Caporiacco, 1935) and O. quesitio Moradmand, 2013. 14 species are recognized as misplaced in Eusparassus, thus nearly half of the described species prior to this revision were placed mistakenly in this genus. Neotypes are designated for E. walckenaeri from Egypt, E. barbarus, E. oraniensis and E. letourneuxi (all three from Algeria) to establish their identity. The male and female of Cercetius perezi Simon, 1902, which was known only from the immature holotype, are described for the first time. It is recognized that the monotypic and little used generic name Cercetius Simon, 1902 — a species, which had been known only from the immature holotype — as a synonym of the widely used name Eusparassus. The case proposal 3596 (conservation of name Eusparassus) is under consideration by ICZN.
The first comprehensive molecular phylogeny of the family Sparassidae with focus on the genus Eusparassus is investigated using four molecular markers (mitochondrial COI and 16S; nuclear H3 and 28S). The monophyly of Eusparassus and the dufouri, walckenaeri and doriae species-groups are recovered with the latter two groups more closely related. The monophyly of the tuckeri-group is not supported and the position of E. jaegeri as the only available member of the jaegeri-group is not resolved within the Eusparassus clade. DNA samples of the vestigator-group were not accessible for this study. The origination of the genus Eusparassus around 70 million years ago (MA) is estimated according to molecular clock analyses. Using this recent result in combination with some biogeographic and geological data, the Namib Desert is proposed as the place of ancestral origin for Eusparassus and putative Eusparassinae genera.
Further analyses are done on the phylogenetic relationships of Sparassidae and its subfamilies. The Eusparassinae are not confirmed as monophyletic, with the two original genera Eusparassus and Pseudomicrommata in separate clades and only the latter clusters with most other assumed Eusparassinae, here termed the "African clade". Monophyly of the subfamilies Sparianthinae, Heteropodinae sensu stricto, Palystinae and Deleninae is recovered. The Sparianthinae are supported as the most basal clade, diverging considerably early (143 MA) from all other Sparassidae. The Sparassinae and genus Olios are found to be polyphyletic. The Sparassidae are confirmed as monophyletic and as most basal group within the RTA-clade. The divergence time of Sparassidae from the RTA-clade is estimated with 186 MA in the Jurassic. No affiliation of Sparassidae to other members of the "Laterigradae" (Philodromidae, Selenopidae and Thomisidae) is observed, thus the crab-like posture of this group was proposed a result of convergent evolution. Only the families Philodromidae and Selenopidae are found members of a supported clade. Including a considerable amount of RTA-clade representatives, the higher-level clade Dionycha is not but monophyly of the RTA-clade itself is supported
Scientometric portrait of Nobel laureate Leland H. Hartwell
No full textLeland H. Hartwell was honoured with the Nobel Prize in Physiology or Medicine (2001) at his 62 years age and at 41 years of research publishing career. The first contribution of the author was in 1961 at the age of 22. The number of his contributions in a year peaked in 1997 when it touched 8. He had 108 publications during 1961 – 2001 in domains: Molecular Biology of Cell Cycle Regulation (43), Genetics of Cell Division (48), Genomic Re-arrangement and DNA Repair (9), Molecular Genetics of Yeast Cell Fission (5), and Drug Target Interaction (3) which were analysed for authorship pattern with his 101 collaborators. Most active researchers having number of publications with Leland H. Hartwell were : Weinert, T. A. (10), Garvik, B. M. (8), McLaughlin, C. S. (8), Jenness, D. D. (5). His productivity coefficient was 0.76 which clearly indicates that his productivity increased after 50 percentile age. Highest collaboration coefficient (1) for Leland H. Hartwell was found during 1963-1965, 1968-1969, 1977, 1981-1983, 1985-1990, 1996 and 1998-2001. Journals have been the most preferred channel of communication where, as many as 96 papers out of 108 have been published. The core journals publishing his papers were: Cell (14), Genetics (12), Mol. Cell Biol. (8), J. Bactariol. (7), J. Cell Biol. ( 7), Science (7) J. Mol. Biol.(6), Exp. Cell Res. (5), and Proc. Nat. Acad. Sci.(5). Publication density is 2.63 and Publication concentration is 14.63. Most prolific keywords in titles of publications were: Saccharomyces cerevisiae , Yeast , Cell division cycle , RAD9, DNA Damage , Genes , Cell cycle, Genetic control , Check point (s) , Cell division , Mutant of Yeast
Alterations of midbrain structure volume, estimated myelin and functional connectivity in idiopathic generalised epilepsy
No full textAlterations of midbrain structure volume, estimated myelin and functional connectivity in idiopathic generalised epilepsy
No full textTe Toi Poto, Te Toi Roa A Critical Evaluation of Māori-State Inclusion in the Ohiwa Harbour Strategy, Aotearoa New Zealand.
No full textIn New Zealand, the State Owned Enterprises Act 1988 [SOE], Local Government Act 2002 [LGA], the Resource Management Act 1991 [RMA] require that government include the voices of Māori, and ensure their contribution to the decision-making processes of local authorities. Accordingly, central and local government have embraced the idea of inclusive partnership as part of policymaking processes informed by shared values both of government and iwi.
Thus, it is not uncommon to see consultations, partnerships and engagement between Māori-state on a range of issues in line with Tikanga and protocols of Māori culture. These transitions reflect contemporary critical policy scholarship that underscores the need to include marginalised voices policymaking, specifically through processes that reflect diverse values. Termed here as ‘procedural inclusion’, these efforts are framed within the wider goal of participatory democracy as part of the efforts to realise an inclusive society. The present research is a critical evaluation of the inclusion of Māori in the processes of policymaking, especially when those processes have been especially designed to be culturally sensitive.
This core objective is developed through the analysis of the case study of iwi/hapū-local government engagement in creating and implementing the Ohiwa Harbour Strategy in New Zealand’s Eastern Bay of Plenty region between 2002- 2008. The strategy engagement, which culminated in a long-term plan to manage and conserve the Ohiwa harbour, is uniquely positioned for this investigation. It is often regarded by its iwi/hapū and local government stakeholders as a success story in iwi/hapū-government engagement. Using a critical qualitative research methodology informed by kaupapa Māori, the study sought to critically evaluate this exemplar of procedural inclusion at multiple levels. At an operational policy level, the research identified the factors that either facilitated or inhibited Māori inclusion in the strategy development process. At another, more substantive level, the study explored the politics of this engagement, and if the goals of procedural inclusion could accommodate the transformative claims of self-determination and kaitiakitanga made by iwi/hapū.
The analysis of interview data with key stakeholders and documents of the strategy process revealed that a range of factors enhance inclusive policymaking for Māori. At a practical level, legislative frameworks, commitment to Tikanga by all parties, and key strategic cultural brokers facilitated the inclusion of Māori, while limited capacity, fear of change and inter-tribal tensions hinder inclusion. The results also show, at another level, that the ability to productively participate in these engagement processes are framed by discursive politics – of the meanings and interpretations emanating from historical contexts, nature of power relationships, and of decisions regarding who represents whom and what is represented. In all, the study points to both advantages and limitations of procedural inclusion. Inclusive policymaking can open possibilities for better management of environmental resources, strengthening Māori political voice, and creating opportunities for livelihoods and with it greater economic and social inclusion. Equally, there are also limits of government-sponsored engagement.
Māori inclusion in policymaking, while positive, does not deliver opportunities for self determination or rangatiratanga in keeping with the Treaty principles of partnership
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