134,080 research outputs found
Artemether resistance in vitro is linked to mutations in PfATP6 that also interact with mutations in PfMDR1 in travellers returning with Plasmodium falciparum infections.
No full textBACKGROUND: Monitoring resistance phenotypes for Plasmodium falciparum, using in vitro growth assays, and relating findings to parasite genotype has proved particularly challenging for the study of resistance to artemisinins.
METHODS: Plasmodium falciparum isolates cultured from 28 returning travellers diagnosed with malaria were assessed for sensitivity to artemisinin, artemether, dihydroartemisinin and artesunate and findings related to mutations in pfatp6 and pfmdr1.
RESULTS: Resistance to artemether in vitro was significantly associated with a pfatp6 haplotype encoding two amino acid substitutions (pfatp6 A623E and S769N; (mean IC50 (95% CI) values of 8.2 (5.7 - 10.7) for A623/S769 versus 623E/769 N 13.5 (9.8 - 17.3) nM with a mean increase of 65%; p = 0.012). Increased copy number of pfmdr1 was not itself associated with increased IC50 values for artemether, but when interactions between the pfatp6 haplotype and increased copy number of pfmdr1 were examined together, a highly significant association was noted with IC50 values for artemether (mean IC50 (95% CI) values of 8.7 (5.9 - 11.6) versus 16.3 (10.7 - 21.8) nM with a mean increase of 87%; p = 0.0068). Previously described SNPs in pfmdr1 are also associated with differences in sensitivity to some artemisinins.
CONCLUSIONS: These findings were further explored in molecular modelling experiments that suggest mutations in pfatp6 are unlikely to affect differential binding of artemisinins at their proposed site, whereas there may be differences in such binding associated with mutations in pfmdr1. Implications for a hypothesis that artemisinin resistance may be exacerbated by interactions between PfATP6 and PfMDR1 and for epidemiological studies to monitor emerging resistance are discussed
Pseudanthias pillai Heemstra & Akhilesh 2012
No full textPseudanthias pillai Heemstra & Akhilesh, 2012 Holotype: SAIAB 86517, 119 mm SL, male. Type locality: off Chavakkadu, Kerala, India (10°30' N, 75°24' E), depth 150 to 200 meters. Illustration: Heemstra & Akhilesh, 2012:153, fig. 40. D: X, 16. A: III, 7. P: 19. C: 15. V: 26 (10 + 16). S: 3. GR: 29 (11 + 28). LL: 36 to 38. CP: 20 to 22. Distribution: Indian Ocean off southwestern coast of India.Published as part of William D. Anderson, Jr., 2018, Annotated checklist of anthiadine fishes (Percoidei: Serranidae), pp. 1-62 in Zootaxa 4475 (1) on page 45, DOI: 10.11646/zootaxa.4475.1.1, http://zenodo.org/record/145328
Pseudanthias pillai Heemstra & Akhilesh 2012
No full textPseudanthias pillai Heemstra & Akhilesh, 2012 Pseudanthias vizagensis Krishna, Rao, & Venu, 2017 Holotype: SAIAB 86517, 119 mm SL, male. Type locality: off Chavakkadu, Kerala, India (10°30′ N, 75°24′ E), depth 150 to 200 meters. Illustration: Heemstra & Akhilesh, 2012:153, fig. 40. Counts: D: X, 16. A: III, 7. P: 19. C: 15. V: 26 (10 + 16). S: 3. GR: 29 (11 + 28). LL: 36 to 38. CP: 20 to 22. Distribution: Indian Ocean off southwestern coast of India.Published as part of Anderson, William D., 2022, Additions and emendations to the annotated checklist of anthiadine fishes (Percoidei: Serranidae), pp. 567-578 in Zootaxa 5195 (6) on page 573, DOI: 10.11646/zootaxa.5195.6.5, http://zenodo.org/record/722395
Knightjonesia Pillai, 2009, new genus
No full text<i>Knightjonesia,</i> new genus <p> <b>Diagnosis</b>. Tube sinistrally coiled; opercular peduncle winged; thoracic membranes not joined over thorax. Thorax bears 4 chaetal fascicles, including collar chaetal fascicle, and 3 uncinal tori on concave side left side; two uncinal tori on convex side. Collar chaetae simple blades i.e., lacking a fin at base of blade; remaining thoracic fascicles lack sickle-shaped chaetae (<i>Apomatus</i> -chaetae); thoracic uncini slender, bearing 1-few rows of teeth; abdominal uncini with several rows of teeth; most anterior uncinal process gouged.</p> <p> <b> Type species: <i>Knightjonesia platyspira</i> (</b> Knight-Jones) 1978 = <i>Helicosiphon platyspira</i> Knight-Jones, 1978.</p> <p> <b>Material examined</b>: <b>Type Material</b>: Holotype of <i>Helicosiphon platyspira</i> Knight-Jones 1978: BM (NH) 1976: 883, Marion Island, Prince Edward Islands, southeast of Port Elizabeth, consisting only of an operculum; and its paratypes BM (NH) 1976: 884–899 from the same locality. The latter consist of several individuals of various sizes, from tiny juveniles to adults, the tubes of many of which remain unopened. Some of them were extracted from their tubes in order to study the stages in formation of peduncular wings.</p> <p> <b>Description</b>. As stated by P. Knight-Jones (1978) the present species is, compared to other spirorbids, a very large species, attaining a coil diameter of 5.0mm when coiled in the same plane. In addition to the generic diagnosis above, see P. Knight-Jones (1978: 233–234) and P. & E. W. Knight-Jones (1994) for further details relating to the tube, worm, chaetae, egg-sac attachment, and other characters. The egg sac and its attachment to the specialized process in the dorsal thoracic groove are shown in Fig. 2E. The brief description which follows is limited to the character of its winged opercular peduncle.</p> <p>Initially the wings are short and faintly recognizable (Fig. 2 B). In a later stage (Fig. 2C), they are narrow and elongated. The more fully developed wings are shown in Figs. 2, A, D & E.</p> <p> <b>Etymology.</b> The genus is dedicated to both Prof. E. Wyn Knight-Jones & the late Dr. Phyllis Knight- Jones, in appreciation of their numerous contributions to our knowledge of the biology and systematics of serpulimorph and sabellid polychaetes, especially spirorbids, besides other areas.</p> <p>Taxonomy of genera belonging to the subfamily Romanchellinae P. Knight-Jones, 1978</p> <p> Among the characters of the subfamily Romanchellinae, included by P. Knight-Jones (1978: 229) and P. & E. W. Knight-Jones (1994: 79), is that the embryos are raised within the tube in an egg sac attached anteriorly by a specialized process to the dorsal thoracic faecal groove. P. & E. W. Knight-Jones (1994: 79) also state that the members of the subfamily are the only spirorbids that possess brush-like abdominal chaetae. P. Knight-Jones (1978: 229–234) included the following genera under the subfamily: <i>Romanchella</i> Caullery & Mesnil (1897), type species <i>Spirorbi</i> s (<i>Romanchella</i>) <i>perrieri</i> Caullery & Mesnil (1897) and <i>Helicosiphon</i> Gravier (1907), type species <i>H. biscoensis</i> Gravier, 1907. On the basis of subsequent studies, P. Knight-Jones & Fordy (1979: 121) include the genus <i>Protolaeospira</i> (Pixell, 1912), redefined by Knight-Jones, 1972 and 10 species of the latter under the <i>Romanchellinae</i>. As defined by Knight-Jones & Walker (1972: 35) <i>Protolaeospira</i> is the same as <i>Marsipospira</i> Bailey, 1969 and includes <i>Pixellia</i> Pillai, 1970. P. Knight-Jones (1978: 233) describes the new species <i>H</i>. <i>platyspira</i>, which is transferred to the new genus <i>Knightjonesia</i>, with <i>K. platyspira</i> P. Knight-Jones, 1978 as its type species in the present paper.</p> <p> Based on the above and present studies, the differences among those genera may be summarized as follows. Opercular peduncle is winged in <i>Knightjonesia</i>, wingless in <i>Romanchella</i>, <i>Helicosiphon</i> and <i>Protolaeospira</i>. Thoracic membranes of the two sides are not joined over the thorax in <i>Knightjonesia</i>, as seen in Knight-Jones (1978: Fig. 18E) and Figs. 1 E & 2 E of the present paper, <i>Helicosiphon</i> P. Knight-Jones (1978: 232–233) and Fig 1D of the present paper, and in <i>Protolaeospira</i>, whereas it is joined over the thorax in <i>Romanchella</i> (see Knight-Jones, 1978: 229, Figs.16B & 17J). Collar chaetae do not consist of a fin and blade but simple blades in <i>Romanchella</i>, <i>Helicosiphon</i> and <i>Knightjonesia</i>, whereas they consist of a fin and blade in <i>Protolaeospira</i>. Sickle-shaped chaetae (<i>Apomatus</i> -chaetae) are absent in the thorax of <i>Knightjonesia</i> and <i>Helicosiphon</i>, whereas they are present in <i>Romanchella</i> and <i>Protolaeospira</i>. The most anterior uncinal process is blunt and gouged in <i>Knightjonesia</i>, <i>Romanchella</i> and <i>Helicosiphon</i>, whereas it is bilobed in <i>Protolaeospira</i>.</p>Published as part of <i>Pillai, Gottfried, 2009, Knightjonesia, a new genus (Polychaeta: Spirorbidae) with a winged opercular peduncle, and its taxonomy, pp. 46-50 in Zootaxa 2059</i> on pages 47-49, DOI: <a href="http://zenodo.org/record/186793">10.5281/zenodo.186793</a>
Hippoporina indica Pillai 1978
No full textHippoporina indica Pillai, 1978 Fig. 13 A–F Hippoporina indica Pillai, 1978: 62, figs 1–4. Hippoporina indica – McCann et al. 2007: 331, fig. 7a–d. Material MALAYSIA: MSL BRY017b, Kuah jetty, Langkawi, fouling mussel shell attached to rope hanging from jetty. MSL BRY022, Pulau Betong, Penang, fouling a bivalve from an oyster raft. MSL BRY023, Sungai Menghulu, Langkawi, fouling a barrel. Description Colony encrusting, multiserial, unilamellar, except for frontal buds covering early astogenetic stages and apparent reparative growths. Autozooids subrectangular, elongate, 0.35–0.63 mm long by 0.23–0.33 mm wide; frontal shield gently convex, pustulose, porous, with large marginal areolar pores and large pseudopores, which are lacking from an apron proximal of orifice; orifice longer than wide (Fig. 13B), about 0.13 mm long by 0.11 mm wide, sinus broad and shallow, with medial edge almost straight, a pair of proximally directed, pointed condyles separating sinus from semicircular poster, closed by cryptocystal calcification in some zooids (Fig. 13C); ovicell hyperstomial, prominent, broader than long, about 0.16–0.18 mm long by 0.21–0.23 mm wide; about 10–20 rimmed pores of various shapes and sizes, becoming overgrown from the margins by a lamina of interior wall (Fig. 13 D–E). Avicularia adventitious, small, about 0.10 mm long by 0.07 mm wide, normally located laterally to orifice and directed distolaterally towards orifice, usually single, lacking in many zooids, occasional avicularia with variable orientations present more proximally; rostrum pointed, arch-shaped; cross-bar calcified, narrow; opesia semielliptical, broader than long. Remarks Despite being described as late as 1978 (from Bombay Harbour), Hippoporina indica is rapidly becoming widespread as an invasive fouling species. It has been reported from the southeastern USA (McCann et al. 2007), New Zealand (Gordon et al. 2008) and Australia (Tilbrook 2012), and its presence in Penang and Langkawi is therefore unsurprising.Published as part of Taylor, Paul D. & Tan, Shau-Hwai Aileen, 2015, Cheilostome Bryozoa from Penang and Langkawi, Malaysia, pp. 1-34 in European Journal of Taxonomy 149 on pages 24-25, DOI: 10.5852/ejt.2015.149, http://zenodo.org/record/378755
Phase Behavior of Multiblock Polymers: Comparison of Theory and Experiments
No full textThis research was supported by the Undergraduate Research Opportunities Program (UROP).Pillai, Naveen; Arora, Akash; Dorfman, Kevin D. (2017). Phase Behavior of Multiblock Polymers: Comparison of Theory and Experiments. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/187844
Government intervention in industrial R & D: Some lessons from the international experience for India
No full textThere is now substantial empirical evidence, based essentially on the experience of developed countries, that there is underinvestment in industrial R&D consequent to the gradual withdrawal of the state. It is generally observed that government can solve this problem of underinvestment in two ways: by increasing the profits of innovators, or by undertaking R&D in areas where the private sector underinvests. An examination of the nature of government intervention in developed countries show that it is increasingly moving towards the latter variety. However, contrary to normal impression, the extent of government intervention in industrial R&D in India is of the former variety. The state has been using tax incentives as the major instrument for stimulating R&D by production enterprises. Direct grants, which has become the dominant instrument of intervention in the west, is considered to be better as it can be targeted towards specific projects. In fact the efficacy of tax incentives to encourage R&D requires further scrutiny. The state in India also have to intervene for making available technically trained manpower to engage in industrial R&D radically redesigning the higher education system, by improving the incentive system for those working in the R&D system etc. The paper thus underscores the fact that there is enough space for the Indian state to increase its interventionist role in industrial research contrary to the arguments for its gradual withdrawal.appropriability, government intervention, industrial R&D system, technology policy
An intrinsic behavioural approach to the gap metric
No full textAn intrinsic trajectory level approach without any recourse to an algebraic structure of a representation is utilized to develop a behavioural approach to robust stability. In particular it is shown how the controllable behaviour can be constructed at the trajectory level via Zorn's Lemma, and this is utilized to study the controllable-autonomous decomposition. Stability concepts are defined and the relation between this framework and the well known difficulties of classical input-output approaches to systems over the doubly infinite time-axis are discussed. The gap distance is generalised to the behavioural setting via a trajectory level definition; and a basic robust stability theorem is established for linear shift invariant behaviours. The robust stability theorem is shown to provide an explicit robustness interpretation to the behavioural H∞ synthesis of Willems and Trentelmann
Predicting the phase behavior of ABAC tetrablock terpolymers: Sensitivity to Flory-Huggins interaction parameters
No full textArora, Akash; Pillai, Naveen; Bates, Frank S; Dorfman, Kevin D. (2018). Predicting the phase behavior of ABAC tetrablock terpolymers: Sensitivity to Flory-Huggins interaction parameters. Retrieved from the University Digital Conservancy, 10.1016/j.polymer.2018.08.070
- …
