130,961 research outputs found
Astyanax troya
No full textAstyanax troya: MACN-Ict 8310, holotype, 73.8 mm, Argentina, Misiones, arroyo Cuñapirú Chico.Published as part of J. M. Mirande, G. Aguilera & M. D. L. M. Azpelicueta, 2006, Astyanax endy (Characiformes: Characidae), a new fish species from the upper Río Bermejo basin, northwestern Argentina., pp. 57-68 in Zootaxa 1286 on page 5
Lepicerus pichilingue Flowers, Shepard and Troya, new species
No full textLepicerus pichilingue Flowers, Shepard and Troya, new species (Figs 1–5) Description. Morphology (Figs 1–2) externally similar to L. inaequalis. Total length 1.6 mm; maximal width 1.0 mm. Body color yellowish; legs, labrum, clypeus, and middle of elytra black. Much of surface with round tubercles. Head between eyes with two longitudinal ridges with tubercles; supra-antennal ridges not pronounced; posterior of head with raised rim that meets anterior margin of prothorax. Clypeus triangular, strongly raised. Submentum and labrum completely covering mandibles and maxillae. Pronotal sides microdentate, slightly curved; posterior angles with a strong tooth projecting laterally; anterolateral corners excavate to receive antennal club. Scutellum small, triangular. Elytra with costae on intervals 3, 6, 8 (short), and 9, extending to apex where 6 and 8 join 9; intervals between costae with row of tubercles parallel to costae; transverse carinae absent; umbo projecting above actual anterolateral angle; strial punctures separated by own width. Epipleura extremely sinuate for reception of metathoracic legs, but not projecting strongly laterally. Wings fully developed; margin with numerous setae. Prosternum short, prosternal spine raised; prosternal carinae raised, parallel through most of length, strongly converging apically; extending only halfway through procoxae. Mesosternum with narrow anterior spine extending between procoxae. Metasternum long; anterior with deep fossa between mesocoxae; longitudinal medial suture; transverse suture just anterior to metacoxae. Legs retractable into grooves in sterna and epipleura. Meso- and metacoxae with flange covering base of trochanter when leg is fully retracted. Protrochanter triangular; meso- and metatrochanters elongately conical; widest at apex. Tibiae with two apical stout setae. Tarsi with two rows of stout setae ventrally. Aedeagus (Figs 3–5) long, narrow, flat; constricted in basal 1 / 4; strongly constricted in apical 1 / 3, then expanded slightly; apex minutely bifid; parameres fused to basal piece; fibula long, slightly sinuate. Female externally identical to male. Egg ovoid; 0.42–0.46 mm long, 0.22 mm wide. Diagnosis. This new species has elytral carinae much less coarse than in L. bufo, but is so similar to L. inaequalis as to require genitalic dissection for conclusive species determination. The elytral carinae of L. pichilingue are somewhat more widely spaced than those of L. inaequalis and there is a row of tiny tubercles between carinae 2 and 3 in L pichilingue. However, these differences are apparent only in a side-by-side comparison of the two species. On the other hand, the differences in the aedeagi (Figs. 3–8) are easily seen. Characters useful in separating the three species are in the key below. Etymology. pichilingue, Spanish, noun in apposition. Named for the Estación Experimental Tropical Pichilingue, where the specimens were collected. Distribution. Known only from the type locality in Ecuador. Specimens Examined: (1 ɗ, 1 Ψ point mounted and dissected, 2 intact). Male HOLOTYPE labeled: ECUADOR, Los Ríos, Estación Experimental Tropical Pichilingue, 5.5 km SW Quevedo, El Empalme Hwy, Lote “La Teca”, S01.08382°; W 79.48425 °, 128m; 25 -IV- 2008, leaf litter R. Troya, leg. (PUCE). Female ALLOTYPE (same data as Holotype) (FSCA). PARATYPES: (2 in alcohol), same data as Holotype (1 PUCE, 1 FSCA). Habitat. This site (Fig. 9) was a pasture for many years before becoming a plantain plantation until nematodes made monoculture plantain uneconomic. It next became a plantain/cacao plantation (D. Vera, pers. comm.). All specimens were from leaf litter, extracted with Winkler funnels. There is a stream approximately 200 m away, down a steep slope. Associated Coleoptera in the soil samples included Staphylinidae, Hydrophilidae, and Corylophidae. Biology. The female had four eggs in the abdomen, so the reproductive period includes April.Published as part of Flowers, Wills, Shepard, William D. & Mera, Roberto Troya, 2010, A new species of Lepicerus (Coleoptera: Lepiceridae) from Ecuador, pp. 35-39 in Zootaxa 2639 on pages 36-37, DOI: 10.5281/zenodo.19854
Modified virtually scaling free adaptive CORDIC rotator algorithm and architecture
No full textIn this article we proposed a novel CoOrdinate Rotation DIgital Computer (CORDIC) rotator algorithm that converges to the final target angle by adaptively executing appropriate iteration steps while keeping the scale factor virtually constant and completely predictable. The new feature of our scheme is that depending on the input angle the scale factor can assume only two values viz., 1 and 1/?2 and it is independent of the number of executed iteration, nature of iteration and wordlength. In this algorithm, compared to the conventional CORDIC a reduction of 50% iteration is achieved on an average without compromising the accuracy. The adaptive selection of the appropriate iteration step is predicted from the binary representation of the target angle and no further arithmetic computation in the angle approximation datapath is required. The convergence range of the proposed CORDIC rotator is spanned over the entire coordinate space. The new CORDIC rotator requires 22% less adders and 53% less registers compared to that of the conventional CORDIC. The synthesized cell area of the proposed CORDIC rotator core is 0.7 mm2 and its power dissipation is 7 mW in IHP in-house 0.25 ?m BiCMOS technology. To our knowledge, this is the smallest pipelined CORDIC rotator reported so far
Low-power VLSI implementation of the inner receiver for OFDM-based WLAN systems
No full textIn this paper, we propose low-power designs for the synchronizer and channel estimator units of the Inner Receiver in wireless local area network systems. The objective of the work is the optimization, with respect to power, area, and latency, of both the signal processing algorithms themselves and their implementation. Novel circuit design strategies have been employed to realize optimal hardware and power efficient architectures for the fast Fourier transform, arc tangent computation unit, numerically controlled oscillator, and the decimation filters. The use of multiple clock domains and clock gating reduces the power consumption further. These blocks have been integrated into an experimental digital baseband processor for the IEEE 802.11a standard implemented in the 0.25mum- 5-metal layer BiCMOS technology from Institute for High Performance Microelectronic
A 16-bit CORDIC rotator for high-performance wireless LAN
No full textIn this paper we propose a novel 16-bit low power CORDIC rotator that is used for high-speed wireless LAN. The algorithm converges to the final target angle by adaptively selecting appropriate iteration steps while keeping the scale factor virtually constant. The VLSI architecture of the proposed design eliminates the entire arithmetic hardware in the angle approximation datapath and reduces the number of iterations by 50% on an average. The cell area of the processor is 0.7 mm2 and it dissipates 7 mW power at 20 MHz frequency
Troya sin Homero : Troya (2004)
No full textSe trata de comentar la película Troya (2004) dirigida por W. Petersen. Tras comentar la dirección, el guión escrito por D. Benioff, los principales actores y el rodaje se pasa a comentar los principales errores. La excesiva ausencia de los dioses se ha querido explicar porque los dioses envidiaban a los mortales y, además, la importancia de cada hombre se mide sólo por su respectiva fama. La salvación, aparte de Eneas, de numerosos troyanos y troyanas (París, Helena, Briseida, Andrómaca) y la muerte en Troya de diversos aqueos (Agamenón, Menelao, Ayax) crea un tremendo vacío sobre toda la tradición legendaria helénica ya que las importantes reflexiones sobre el matricidio de Orestes o el triste destino de las troyanas cautivas desaparecen en una película en la que su guionista pretendía criticar el belicismo a base de anacronismos que no ayudan a comprender el presente y, mucho menos, a entender el pasado.What follows is as comentary on Troy (2004), the motion picture directed by W. Petersen. After dealing with direction, D. Benioff's script, main a actors and shooting, some mistakes in the film are underlined. An excessive absence of gods has beer and fame makes every man prominent. Redemption of several Trojans (Paris, Helen, Briséis, Andromache), apart from Aeneas and then some Aecheans dyng in Troy (Agammenon, Menelaus, Aias), creates a huge void in the whole legendary tradition. The rather important reflection: of some captive Trojan women just disappear from a film whose script writer theoretically wanted to doing anachronisme does not actually help us to understand the present, not to mention the past
A new species of Lepicerus (Coleoptera: Lepiceridae) from Ecuador
No full textFlowers, Wills, Shepard, William D., Mera, Roberto Troya (2010): A new species of Lepicerus (Coleoptera: Lepiceridae) from Ecuador. Zootaxa 2639: 35-39, DOI: 10.5281/zenodo.19854
Efficient inner-receiver design for OFDM-based WLAN systems: Algorithm and architecture
No full textIn this article we propose a complete solution for the so-called Inner Receiver of an OFDM-WLAN system based on the IEEE 802.11a standard. Our work has been divided into two parts. In this Part – I we concentrate our investigations on three key components forming the Inner Receiver namely, the Synchronizer, the Channel Estimator and the Digital Timing Loop. The main goal is the joint optimization of the signal processing algorithms along with the implementation friendly VLSI architecture required for these three key components in order to reduce power, area and latency, without compromising the performance excessively. We provide both the mathematical details and extensive computer simulations to validate our proposals
FIGURES 1–2. Lepicerus pichilingue. 1 in A new species of Lepicerus (Coleoptera: Lepiceridae) from Ecuador
No full textFIGURES 1–2. Lepicerus pichilingue. 1, dorsal view; 2, ventral view.Published as part of Flowers, Wills, Shepard, William D. & Mera, Roberto Troya, 2010, A new species of Lepicerus (Coleoptera: Lepiceridae) from Ecuador, pp. 35-39 in Zootaxa 2639 on page 36, DOI: 10.5281/zenodo.19854
Lepicerus
No full textKey to Known Species of Lepicerus 1 Elytral carinae strongly raised and interrupted along their length; aedeagus with fibula robust and notched at apex (Navarrete-Heredia et al. 2005); total length 1.8 –2.0 mm; Mexico ............................................................ bufo Hinton 1 ʹ Elytral carinae raised only slightly, not interrupted along their length; fibula of aedeagus slender, not notched at apex (Figs 3–8); total length less than 1.7 mm...................................................................................................................... 2 2. Aedeagus elongate and slender, 0.68 mm long, width 1 / 5 of length (Figs 3–5); known from Ecuador........................ ........................................................................................................................... pichilingue Flowers, Shepard & Troya 2 ʹ Aedeagus shorter and more robust, narrowing at apex, 0.57 mm long, width 1 / 4 of length (Figs 6–8); known from Central America...................................................................................................................... inaequalis MotschulskyPublished as part of Flowers, Wills, Shepard, William D. & Mera, Roberto Troya, 2010, A new species of Lepicerus (Coleoptera: Lepiceridae) from Ecuador, pp. 35-39 in Zootaxa 2639 on page 38, DOI: 10.5281/zenodo.19854
- …
