1,059 research outputs found

    Length-weight relationships for some important forage crustaceans from South Africa

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    The diet of marine animals is usually determined by stomach content analysis. Although partially digested prey fragments can often be identified to species level, it is difficult to estimate the original mass of the prey organism. This information, however, is essential for calculating both the total food intake as well as the relative contribution of each prey item. In this study we present regression equations that can be used to estimate the original mass of 18 common South African crustaceans from various indigestible fragments such as the carapace (length and width), chelae (length and width of left and right dactylus) and eye (length and width)

    Synopsis of Acanthocerini (Hemiptera, Coreidae) from Argentina

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    Eight genera and 13 species of the tribe Acanthocerini are recorded in Argentina, i.e., Athaumastus haematicus (Stål), Athaumastus macer Brailovsky, Athaumastus subcarinatus (Stål), Athaumastus subterlineatus Bergroth, Beutelspacoris sanchezi Brailovsky, Beutelspacoris dilatata Casini, Camptischium clavipes (Fabricius), Crinocerus sanctus (Fabricius), Dersagrena flaviventris (Berg), Dersagrena lacerdae (Signoret), Dersagrena subfoveolata (Berg), Thlastocoris hernandezi Brailovsky and Zoreva dentipes Fabricius. Redescriptions are given for Athaumastus haematicus, Athaumastus subcarinatus and Dersagrena flaviventris with photographs of male and female genitalia of Dersagrena subfoveolata. Zoreva recorded from Argentina the first time. New locality records are given for Buenos Aires, Chaco, Formosa, Misiones, and Tucumán.Fil: Pall, José Luis María. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Coscarón, María del Carmen. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    An Approach to Assess Solder Interconnect Degradation Using Digital Signal

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    Department of Human and Systems EngineeringDigital signals used in electronic systems require reliable data communication. It is necessary to monitor the system health continuously to prevent system failure in advance. Solder joints in electronic assemblies are one of the major failure sites under thermal, mechanical and chemical stress conditions during their operation. Solder joint degradation usually starts from the surface where high speed signals are concentrated due to the phenomenon referred to as the skin effect. Due to the skin effect, high speed signals are sensitive when detecting the early stages of solder joint degradation. The objective of the thesis is to assess solder joint degradation in a non-destructive way based on digital signal characterization. For accelerated life testing the stress conditions were designed in order to generate gradual degradation of solder joints. The signal generated by a digital signal transceiver was travelling through the solder joints to continuously monitor the signal integrity under the stress conditions. The signal properities were obtained by eye parameters and jitter, which represented the characteristics of the digital signal in terms of noise and timing error. The eye parameters and jitter exhibited significant increase after the exposure of the solder joints to the stress conditions. The test results indicated the deterioration of the signal integrity resulted from the solder joint degradation, and proved that high speed digital signals could serve as a non-destructive tool for sensing physical degradation. Since this approach is based on the digital signals used in electronic systems, it can be implemented without requiring additional sensing devices. Furthermore, this approach can serve as a proactive prognostic tool, which provides real-time health monitoring of electronic systems and triggers early warning for impending failure.ope

    New taxa of Epiphloeinae Kuwert (Cleridae) and Chaetosomatidae Crowson (Coleoptera: Cleroidea)

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    Twenty-one new taxa of Cleridae and one of Chaetosomatidae are described including four new genera: Acanthocollis, Decaphloeus, Megaphloeus, and Stegnoclava. Twenty new species are described: five species of Amboakis Opitz (A. ampla, A. antegalba, A. diffusa, A. demagna, A. waodani, one species of Epiphloeus Spinola (E. erwini), four species of Madoniella Pic (M. aspera, M. darlingtoni, M. divida, M. spilota), two species of Plocamocera Spinola (P. clinata, P. lena), seven species of Pyticeroides Kuwert (P. latisentis, P. moraquesi, P. parvoporis, P. pinnacerinis, P. pullis, P. turbosiris, P. ustulatis), and one species of Chaetosomatidae (Chaetosoma colossa)

    Optimization of multi-gigabit transceivers for high speed data communication links in HEP Experiments

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    The scheme of the data acquisition (DAQ) architecture in High Energy Physics (HEP) experiments consist of data transport from the front-end electronics (FEE) of the online detectors to the readout units (RU), which perform online processing of the data, and then to the data storage for offline analysis. With major upgrades of the Large Hadron Collider (LHC) experiments at CERN, the data transmission rates in the DAQ systems are expected to reach a few TB/sec within the next few years. These high rates are normally associated with the increase in the high-frequency losses, which lead to distortion in the detected signal and degradation of signal integrity. To address this, we have developed an optimization technique of the multi-gigabit transceiver (MGT) and implemented it on the state-of-the-art 20nm Arria-10 FPGA manufactured by Intel Inc. The setup has been validated for three available high-speed data transmission protocols, namely, GBT, TTC-PON and 10 Gbps Ethernet. The improvement in the signal integrity is gauged by two metrics, the Bit Error Rate (BER) and the Eye Diagram. It is observed that the technique improves the signal integrity and reduces BER. The test results and the improvements in the metrics of signal integrity for different link speeds are presented and discussed

    Doryctopambolus nunes & Zaldívar-Riverón (Braconidae), a new Neotropical doryctine wasp genus with propodeal spines

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    The new Neotropical doryctine genus Doryctopambolus gen. n. is erected to contain D. pilcomayensis (van Achterberg & Braet, 2004), comb. n., which was previously placed within Pambolus (Pambolinae), as well as three new species, D. clebschi sp. n., D. dominicanus sp. n. and D. sarochensis sp. n. Membersof this new genus are mainly characterised by the presence of at least one pair of conspicuous propodeal apico-lateral projections, which are similar to those present in all members of Pambolinae and in species of three Australasian doryctine genera. We generated DNA barcoding sequences for the three newly described species. We discuss the morphological similarity between species of the Australasian Echinodoryctes Belokobylskij, Iqbal & Austin and Doryctopambolus. A key for the described species of Doryctopambolus is provided.Fil: Nunes, Juliano Fiorelini. Universidade Federal de Minas Gerais; BrasilFil: Zaldívar Riverón, Alejandro. Universidad Nacional Autónoma de México; MéxicoFil: de Castro, Clóvis Sormus. Universidade Federal do São Carlos; BrasilFil: Marsh, Paul M.. No especifica;Fil: Penteado Dias, Angélica Maria. Universidade Federal do São Carlos; BrasilFil: Briceño, Rosa. Universidad Centroccidental Lissandro Alvarado; VenezuelaFil: Martinez, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin

    Los estados adultos de Nanomis y Spiritiops (Ephemeroptera: Baetidae)

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    The adult stages of Nanomis Lugo-Ortiz & McCafferty and Spiritiops Lugo-Ortiz & McCafferty are described for the first time based on reared material from Argentina and Brazil, respectively. They can be differentiated from the other adults of Baetidae by the following characters: Nanomis, hind wings with three longitudinal veins, second vein bifurcate; costal projection of the hind wings pointed, placed in the basal third of anterior margin; and forceps three-segmented, third segment rounded. Spiritiops, fore wings with paired and long marginal intercalary veins; hind wings with three complete longitudinal veins, and an incomplete small longitudinal vein; costal projection of hind wings pointed, broad at base and placed in the basal third of anterior margin; forceps three-segmented, second segment constricted and third segment elongate and narrowed.Los estados adultos de Nanomis Lugo-Ortiz & McCafferty y Spiritiops Lugo-Ortiz & McCafferty se describen por primera vez sobre la base de material criado de Argentina y Brasil respectivamente. Se distinguen de los restantes adultos de Baetidae por la siguiente combinación de caracteres: Nanomis, alas posteriores con tres venas longitudinales, la segunda bifurcada; proyección costal de las alas posteriores aguda, ubicada basalmente en el margen anterior del ala; fórceps trisegmentados, tercer segmento redondeado. Spiritiops, alas anteriores con venas marginales intercalares pares; alas posteriores con 3 venas longitudinales completas y una vena longitudinal corta e incompleta; proyección costal de las alas posteriores aguda apicalmente y con base ancha, ubicada en el tercio basal del margen anterior; fórceps trisegmentados, segundo segmento con una constricción y tercer segmento alargado y angosto.Fil: Salles, Frederico Falcão. Universidade Federal do Espírito Espírito Santo; BrasilFil: Nieto Peñalver, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; Argentin
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