1,684 research outputs found
Trachelostenini sensu novo: redescriptions of Trachelostenus Solier, Myrmecodema Gebien and Leaus Matthews & Lawrence, based on adults and larvae, and descriptions of three new species of Leaus (Coleoptera: Tenebrionidae)
No full textMatthews, Eric G., Lawrence, John F. (2015): Trachelostenini sensu novo: redescriptions of Trachelostenus Solier, Myrmecodema Gebien and Leaus Matthews & Lawrence, based on adults and larvae, and descriptions of three new species of Leaus (Coleoptera: Tenebrionidae). Zootaxa 4020 (2): 289-312, DOI: 10.11646/zootaxa.4020.2.
Leaus tasmanicus Matthews & Lawrence 1992
No full text<i>Leaus tasmanicus</i> Matthews & Lawrence, 1992 <p>(Figs 21, 27, 33, 39, 40, 44, 47, 48, 54, 56)</p> <p> <b>Redescription. Adult</b>. With the characteristics of the genus. Length 6.5–8.4 mm. Maximum width of prothorax 1.5–1.6 mm, width at elytral bases 2.0– 2.1 mm. <i>Prothorax</i> subquadrate, lateral margins entire, disc with a pair of low median tumosities followed by shallow transverse basal depression. <i>Pterothorax</i>: Elytral disc with pair of low basal tumosities followed by shallow depressions. <i>Abdomen</i>: Ovipositor with terminal gonostyli (Matthews & Lawrence, 1992, fig.7). Vaginal sclerite with lateral wings straight. Aedeagal parameres with minute spinules (Matthews & Lawrence, 1992, fig. 4).</p> <p> <b>Description. Larva</b>. See generic description above.</p> <p> <b>Distribution</b>. Western Tasmania in temperate rainforest. The only known additional collection localities since those listed in Matthews & Lawrence (1992) are Lake Dobson 2003, J. Balderson (ANIC) and the locality for the larva cited above.</p>Published as part of <i>Matthews, Eric G. & Lawrence, John F., 2015, Trachelostenini sensu novo: redescriptions of Trachelostenus Solier, Myrmecodema Gebien and Leaus Matthews & Lawrence, based on adults and larvae, and descriptions of three new species of Leaus (Coleoptera: Tenebrionidae), pp. 289-312 in Zootaxa 4020 (2)</i> on page 304, DOI: 10.11646/zootaxa.4020.2.4, <a href="http://zenodo.org/record/236475">http://zenodo.org/record/236475</a>
Leaus monteithi Matthews & Lawrence, 2015, sp. n.
No full textLeaus monteithi sp. n. (Figs 5, 22, 25, 30, 34) Description. With the characteristics of the genus. Length 5.3 –6.0 mm, maximum width of prothorax 1.5–1.7 mm, width at humeri 1.9 –2.0 mm. Legs flavo-castaneous at bases and apices of femora and most of tibiae, otherwise fuscous. Prothorax with sides unevenly convex, widest at basal third, lateral carinae simple, disc with pair of low median tumosities on either side of depressed and glabrous median line, basally shallowly transversely depressed. Pterothorax. Elytra with strong basal tumosities and moderately deep transverse depression behind them. Abdomen. Ovipositor without gonostyli. Vaginal sclerite with wings anteriorly recurved. Aedeagal parameres simple. Larva unknown. Distribution. Northern NSW in open eucalypt forest, obtained by pyrethrum fogging of moss on a tree trunk by Geoff Monteith (QMBA), after whom the species is named. Type specimens: Holotype ♀: NSW: 30 o 29 ’ 42 ”S, 152 o 21 ’ 27 ” Point Lookout Rd, radar beacon, 1390m, 13–14 Nov 2008. G. Monteith. Pyrethrum, trees, open for. (QMBA T 228901). Paratypes: same data as holotype, 1 ♂, 1 sex not determined (QMBA), 2 ♀♀ in spirit COL 427 (ANIC)Published as part of Matthews, Eric G. & Lawrence, John F., 2015, Trachelostenini sensu novo: redescriptions of Trachelostenus Solier, Myrmecodema Gebien and Leaus Matthews & Lawrence, based on adults and larvae, and descriptions of three new species of Leaus (Coleoptera: Tenebrionidae), pp. 289-312 in Zootaxa 4020 (2) on page 310, DOI: 10.11646/zootaxa.4020.2.4, http://zenodo.org/record/23647
Leaus Matthews & Lawrence 1992
No full textLeaus Matthews & Lawrence, 1992 (Figs 5, 10, 20 –36, 39, 40, 44, 47, 48, 50, 51, 54, 56) Type species. Leaus tasmanicus Matthews & Lawrence, 1992, by monotypy. Redescription. Adults. With the characteristics of the tribe. Length 3.9–8.4 mm. Body parallel-sided, 2.2 –3.0 times as long as wide. Upper surfaces nitid fuscous or castaneous, clothed with recumbent white setae forming patterns on dark background, also with long sparse erect pilosity. Head: Basal membrane of labrum narrow but exposed and complete. Eyes entire, broadly oval. Antennae short, not quite reaching base of prothorax, antennomeres obconic, gradually widening distally, apical segment large and suboval. Mentum small, subquadrate or a little transverse. Prothorax: Pronotum densely punctate, moderately convex, lateral carinae present. Procoxal cavities internally open. Trochantins absent. Pterothorax: Elytral disc at least slightly uneven, without striae, with partly effaced puncture rows. Wings fully developed. Legs: Procoxae subconical, approximated, projecting well below prosternum. Tarsi about as long as tibiae. Abdomen: Intercoxal process narrowly triangular. First three ventrites connate. Defensive glands present, small, widely separated. Female: Ovipositor with paraprocts elongate, about twice as long as coxites, baculi of first coxite lobes diagonal, short, coxites with four distinct pairs of lobes. Spermatheca coiled, attached to base of accessory gland. Single vaginal sclerite with median keel and transverse lateral wings. Description. Larva. With the characteristics of the tribe. Dorsal surfaces bicolored with a complex pattern of dark brown markings on a yellow background. Head with sides subparallel (Fig. 40); larger anterior epipharyngeal sensilla (Fig. 54) with anterior 2 moderately widely separated and well separated from the posterior 4, which form a subquadrate cluster; posterior sensilla forming two longitudinal rows of 4; mandibles bidentate with short subapical tooth on incisor edge; left mola with several weak transverse ridges; gula 3 times as long as wide; hypopharyngeal sclerome anteriorly trilobed. Prothorax almost as long as wide. Legs slightly longer than thoracic width and clothed with fine hairs. Abdomen about 3.5 times as long as thorax; tergum I with weak anterior carina; tergum IX (Fig. 47) slightly shorter at midline and slightly narrower than VIII, carina simple; urogomphi (Fig. 48) each with 4 setiferous tubercles at about middle; surface of concave disc lightly pigmented, dark-rimmed pits less regularly spaced and concentrated around a pair of posterolateral impressions; segment X with a pair of tubular pygopods (Fig. 44). Spiracles annular-cribriform with the peritreme completely surrounded by a cribriform plate (Fig. 56). Larval material examined: Leaus tasmanicus Matthews & Lawrence. AUS: Tasmania: Pelion (41.50 S, 146.08 E), 1991, pyrethrin knockdown, rainforest, P. Greenslade & M. Comfort (ANIC). Discussion. At the time of its description Leaus was placed in Heleini because it shows the basal tenebrionine characteristics of that tribe and, in particular, similarities to the heleine genus Lepispilus. Both Leaus and Lepispilus have pale dorsal setae which form a mottled pattern, and they share the unusual character of a vaginal sclerite. At the same time, it was mentioned that there is a resemblance between Leaus and Trachelostenus in the form of prominent coxae. Later, Matthews (2003) transferred Leaus to Titaenini, another basal tribe of Tenebrioninae, as discussed in the introduction. We now know that Titaenini as then conceived by Matthews was a paraphyletic assemblage of primitive Tenebrioninae sharing mainly plesiomorphies. Lepispilus differs from Leaus in the absence of prominent coxae, presence of a medial fleck on the wings, complete elytral epipleura, aedeagal alae not of the appendiculate type, and unique ovipositor structure. The ovipositor of Lepispilus (illustrated in Matthews & Bouchard 2008, fig. 47 C) does not resemble that of any other known tenebrionid. There is therefore no evidence of a direct relationship between Lepispilus and Leaus or any other trachelostenine. The peculiar type of spiracular opening surrounded by a cribriform plate in larvae of Leaus (called annularcribriform by Lawrence et al. 2011) is perhaps an adaptation to wetter habitats and has been found sporadically in various other unrelated families of Coleoptera including Trogossitidae-Lophocaterinae, Mycteridae-Hemipeplinae, and Chrysomelidae-Cryptocephalinae.Published as part of Matthews, Eric G. & Lawrence, John F., 2015, Trachelostenini sensu novo: redescriptions of Trachelostenus Solier, Myrmecodema Gebien and Leaus Matthews & Lawrence, based on adults and larvae, and descriptions of three new species of Leaus (Coleoptera: Tenebrionidae), pp. 289-312 in Zootaxa 4020 (2) on pages 301-304, DOI: 10.11646/zootaxa.4020.2.4, http://zenodo.org/record/23647
Leaus tropicalis Matthews & Lawrence, 2015, sp. n.
No full text<i>Leaus tropicalis</i> sp. n. <p>(Figs 10, 20, 24, 28, 29, 35)</p> <p> <b>Description</b>. With the characteristics of the genus. Length 4.0– 4.5 mm, maximum width of prothorax 1.0– 1.2 mm, width at humeri 1.2–1.6 mm. <i>Prothorax</i> with sides evenly convex and lateral carinae strongly irregularly dentate, disc evenly convex. <i>Pterothorax</i>. Elytra slightly tumescent at bases. <i>Abdomen</i>: Ovipositor with terminal gonostyli. Vaginal sclerite with central keel partly divided into two blades, and lateral halberd-shaped wings separated from central keel by narrow membranes. Aedeagal parameres simple. Larva unknown.</p> <p> <b>Distribution</b>. <i>L. tropicalis</i> is found in three of the 17 generally recognised montane blocks in the Queensland Wet Tropics: the Carbine Tableland (A4), Atherton Tableland (A9) and Mount Bellenden Ker (A10) at altitudes of 1150–1500m. A4 and A10 are the areas of highest diversity and endemism, which have served as stable refugia for a long geological period (Bouchard <i>et al</i>. 2005).</p> <p> <b>Type specimens. Holotype</b> ♀: NE Q: 16o24’S x 145o13’E 3.5 km NNE Mt Spurgeon 16 Oct 1991 1330 m Monteith & Janetzki Pyrethrum, trees & rocks (QMBA T 228900). <b>Paratypes</b>: ♂, 17.28S 145.29E QLD, Longlands Gap BS1 1150m 1 Sept-2 Oct. 1995 L. Umback Malaise trap (ANIC); ♀ NEQ: 17o24’Sx 145o49’E, Bartle Frere top camp 1500m 29 Nov 1998 G. Monteith Pyrethrum trees, R.F.1978 (QMBA); ♀, 17.06S 145.36E QLD, Mt Haig GS1 1150m, 3 Jan.-4 Feb.1995, P. Zborowski, Malaise traps (ANIC).</p>Published as part of <i>Matthews, Eric G. & Lawrence, John F., 2015, Trachelostenini sensu novo: redescriptions of Trachelostenus Solier, Myrmecodema Gebien and Leaus Matthews & Lawrence, based on adults and larvae, and descriptions of three new species of Leaus (Coleoptera: Tenebrionidae), pp. 289-312 in Zootaxa 4020 (2)</i> on page 310, DOI: 10.11646/zootaxa.4020.2.4, <a href="http://zenodo.org/record/236475">http://zenodo.org/record/236475</a>
Disruption of the developmental programme of Trypanosoma brucei by genetic ablation of TbZFP1, a differentiation-enriched CCCH protein
No full textThe regulation of differentiation is particularly important in microbial eukaryotes that inhabit multiple environments. The parasite Trypanosoma brucei is an extreme example of this, requiring exquisite gene regulation during transmission from mammals to the tsetse fly vector. Unusually, trypanosomes rely almost exclusively on post-transcriptional mechanisms for regulated gene expression. Hence, RNA binding proteins are potentially of great significance in controlling stage-regulated processes. We have previously identified TbZFP1 as a trypanosome molecule transiently enriched during differentiation to tsetse midgut procyclic forms. This small protein (101 amino acids) contains the unusual CCCH zinc finger, an RNA binding motif. Here, we show that genetic ablation of TbZFP1 compromises repositioning of the mitochondrial genome, a specific event in the strictly regulated differentiation programme. Despite this, other events that occur both before and after this remain intact. Significantly, this phenotype correlates with the TbZFP1 expression profile during differentiation. This is the first genetic disruption of a developmental regulator in T. brucei. It demonstrates that programmed events in parasite development can be uncoupled at the molecular level. It also further supports the importance of CCCH proteins in key aspects of trypanosome cell function
Leaus
No full textLeaus species (Figs 23, 26, 32) A specimen of a species which appears to be identical to L. elusus except for distinctly denticulate lateral pronotal carinae bears the label: ‘Qld: 27.293 o Sx 152.745 o E 0.5 km W Mt Tenison Woods, N side. RF. 615m. Malaise. 19160 30 Oct—06 Nov 2009. G. Monteith & F. Turco’ COL 1085 (ANIC). It is in alcohol for DNA sequencing and therefore not suitable as a holotype. It is unquestionably a different species from L. elusus not only because of its different pronotal sides but also because the collection locality is in lowland rainforest while that of the latter is in highland sclerophyll forest. Since it is a female the opportunity was taken to examine the ovipositor and vaginal sclerite. The ovipositor is without gonostyli (Fig. 26) as in L. monteithi.Published as part of Matthews, Eric G. & Lawrence, John F., 2015, Trachelostenini sensu novo: redescriptions of Trachelostenus Solier, Myrmecodema Gebien and Leaus Matthews & Lawrence, based on adults and larvae, and descriptions of three new species of Leaus (Coleoptera: Tenebrionidae), pp. 289-312 in Zootaxa 4020 (2) on pages 310-311, DOI: 10.11646/zootaxa.4020.2.4, http://zenodo.org/record/23647
The developmental cell biology of Trypanosoma brucei
No full textTrypanosoma brucei provides an excellent system for studies of many aspects of cell biology, including cell structure and morphology, organelle positioning, cell division and protein trafficking. However, the trypanosome has a complex life cycle in which it must adapt either to the mammalian bloodstream or to different compartments within the tsetse fly. These differentiation events require stage-specific changes to basic cell biological processes and reflect responses to environmental stimuli and programmed differentiation events that must occur within a single cell. The organization of cell structure is fundamental to the trypanosome throughout its life cycle. Modulations of the overall cell morphology and positioning of the specialized mitochondrial genome, flagellum and associated basal body provide the classical descriptions of the different life cycle stages of the parasite. The dependency relationships that govern these morphological changes are now beginning to be understood and their molecular basis identified. The overall picture emerging is of a highly organized cell in which the rules established for cell division and morphogenesis in organisms such as yeast and mammalian cells do not necessarily apply. Therefore, understanding the developmental cell biology of the African trypanosome is providing insight into both fundamentally conserved and fundamentally different aspects of the organization of the eukaryotic cell
A Delayed and Subsampled Wideband Sparse Array for Joint Angle and Frequency Estimation
No full textIn this paper we consider the problem of joint wideband spectrum sensing and direction-of-arrival (DoA) estimation, where a number of uncorrelated narrowband sources spread over a wide frequency band impinge on a sparse linear array (SLA). To overcome the sampling rate bottleneck for wideband spectrum sensing, we rely on sub-Nyquist sampling for the receiver, and to resolve the sources both in the angle and frequency domain, an additional delayed branch is included for every antenna to gain an extra degree of freedom (DoF). Appropriately designing the delays at the different antennas allows us to use the contemporary machinery of co-array processing. We accordingly propose a joint eigenvalue decomposition (EVD) based algorithm to jointly estimate the angles and frequencies of the different sources with automatic pairing. Furthermore, as a consequence of the co-array processing, we can handle more sources than the number of physical antennas. Simulation results are included to corroborate our findings.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Signal Processing System
Cytochrome oxidase subunit VI of Trypanosoma brucei is imported without a cleaved presequence and is developmentally regulated at both RNA and protein levels
No full textMitochondrial respiration in the African trypanosome undergoes dramatic developmental stage regulation. This requires co-ordinated control of components encoded by both the nuclear genome and the kinetoplast, the unusual mitochondrial genome of these parasites. As a model for understanding the co-ordination of these genomes, we have examined the regulation and mitochondrial import of a nuclear-encoded component of the cytochrome oxidase complex, cytochrome oxidase subunit VI (COXVI). By generating transgenic trypanosomes expressing intact or mutant forms of this protein, we demonstrate that COXVI is not imported using a conventional cleaved presequence and show that sequences at the N-terminus of the protein are necessary for correct mitochondrial sorting. Analyses of endogenous and transgenic COXVI mRNA and protein expression in parasites undergoing developmental stage differentiation demonstrates a temporal order of control involving regulation in the abundance of, first, mRNA and then protein. This represents the first dissection of the regulation and import of a nuclear-encoded protein into the cytochrome oxidase complex in these organisms, which were among the earliest eukaryotes to possess a mitochondrion
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