3,512 research outputs found
The leucografa species group of Megachile (Chrysosarus) (Hymenoptera: Megachilidae)
No full textRoig-Alsina, A., Torretta, J.P. (2021): The leucografa species group of Megachile (Chrysosarus) (Hymenoptera: Megachilidae). Journal of Natural History 55 (7-8): 457-470, DOI: 10.1080/00222933.2021.1905097, URL: http://dx.doi.org/10.1080/00222933.2021.190509
Figure 4 in The leucografa species group of Megachile (Chrysosarus) (Hymenoptera: Megachilidae)
No full textFigure 4. Megachile obscurior, male: (a) S5; (b) S6; (c) S8; (d) genital capsule, ventral view. Scale bar: 1 mm.Published as part of Roig-Alsina, A. & Torretta, J.P., 2021, The leucografa species group of Megachile (Chrysosarus) (Hymenoptera: Megachilidae), pp. 457-470 in Journal of Natural History 55 (7-8) on page 462, DOI: 10.1080/00222933.2021.1905097, http://zenodo.org/record/547546
Figure 2 in The leucografa species group of Megachile (Chrysosarus) (Hymenoptera: Megachilidae)
No full textFigure 2. Lateral habitus of Megachile species of the M. leucografa group: (a). M. leucografa, female; (b) M. leucografa, male; (c). M. obscurior, female holotype; (d) M. obscurior, male; (e) M. rancaguensis, female holotype; (f) M. rancaguensis, male. Scale bars: 1 mm.Published as part of Roig-Alsina, A. & Torretta, J.P., 2021, The leucografa species group of Megachile (Chrysosarus) (Hymenoptera: Megachilidae), pp. 457-470 in Journal of Natural History 55 (7-8) on page 461, DOI: 10.1080/00222933.2021.1905097, http://zenodo.org/record/547546
Figure 3 in The leucografa species group of Megachile (Chrysosarus) (Hymenoptera: Megachilidae)
No full textFigure 3. (a–c). Megachile obscurior: (a) female holotype, face; (b) holotype labels; (c) male, left antenna; (d–f). M. rancaguensis; (d) female holotype, face; (e) holotype labels; (f), male, left antenna.Published as part of Roig-Alsina, A. & Torretta, J.P., 2021, The leucografa species group of Megachile (Chrysosarus) (Hymenoptera: Megachilidae), pp. 457-470 in Journal of Natural History 55 (7-8) on page 462, DOI: 10.1080/00222933.2021.1905097, http://zenodo.org/record/547546
Heterostylum ferrugineum
No full textHeterostylum ferrugineum (Fabricius) Material examined. New records. ARGENTINA. Buenos Aires: Isla Martín García (34°11′S, 58°15′W), 5.xii.2013, J.P. Torretta (2 ♀, FAUBA); Isla Martín García, 25.ii.2014, J.P. Torretta (1 ♀, 1 ♂, MACN); Isla Martín García, 17.xii.2014, J.P. Torretta (3 ♀, FAUBA). Distribution. Argentina (Buenos Aires. New record) , Brazil (Bahía, Ceará, Goiás, Mato Grosso, Roraima), Paraguay (Asunción), Puerto Rico (San Juan), American Virgin Islands and British Virgin Islands (Road Town) (Fig. 1). Remarks. This species is recorded for the first time from Argentina, based on seven (six females and one male) individuals captured with sweep nets in sandy areas in the Natural and Historical Reserve of Isla Martín García (Fig. 1). This small island (168 ha) lies at the confluence of the Uruguay and Paraná rivers and is an outcrop of the crystalline basement, with different vegetational types (Ferretti et al. 2010). The specimens captured at this site expands the southern end of the species distribution more than 1,000 km. The females were captured hovering at 10–15 cm above the soil surface, possibly searching for nests of solitary bees.Published as part of Torretta, Juan P., Haedo, Joana P., Marrero, Hugo J. & Lamas, Carlos J. E., 2021, New austral-most records of the genus Heterostylum Macquart (Diptera Bombyiliidae) in Argentina, pp. 583-586 in Zootaxa 4990 (3) on pages 583-584, DOI: 10.11646/zootaxa.4990.3.10, http://zenodo.org/record/502686
Heterostylum hirsutum
No full textHeterostylum hirsutum (Thunberg) Material examined. New records. ARGENTINA. Buenos Aires: Villalonga (40°03′S, 62°29′W), 12.i.2018, ex Medicago sativa, J.P. Haedo & H.J. Marrero (2 ♀, FAUBA); Villalonga, 12.i.2018, ex Centaurea solstitialis, J.P. Haedo & H.J. Marrero (1 ♂, FAUBA); Villalonga, 27.xii.2018, ex Medicago sativa, J.P. Haedo & H.J. Marrero (1 ♀, MACN); Villalonga, 8.i.2019, ex Medicago sativa, J.P. Haedo & H.J. Marrero (1 ♀, MACN). Formosa: San Francisco de Laishi: Reserva El Bagual (26°18′S, 58°49′W), 19.xi.2012, J.P. Torretta (1 ♀, MACN); San Francisco de Laishi: Reserva El Ba- gual (on one large nest aggregation of Diadasina distincta), 8.i.2014, J.P. Torretta (3 ♀, FAUBA). Distribution. Argentina (La Rioja, Buenos Aires and Formosa. New records), Brazil (Mato Grosso do Sul), Colombia (Magdalena), Venezuela (La Guaira) (Fig. 1). Remarks. Two new provincial records for this species are presented here from Argentina, Formosa and Buenos Aires. Four female individuals were captured with sweep nets in the Reserva El Bagual (Fig. 1), in Formosa province. The Reserva El Bagual consists of ca. 3,700 ha and is an open savanna located to the east of the humid Chaco region, with different forest types covering diverse environments (Maturo et al. 2005). Three females were captured hovering and ejecting eggs on one large nest aggregation of Diadasina distincta (Holmberg) (Apidae: Emphorini). We were unable to determine if H. hirsutum successfully parasitized the brood cells of D. distincta, but if confirmed this would represent the first host record for this bee fly species. This site is intermediate to the previous records for the southern populations of the species (La Rioja in Argentina and Mato Grosso in Brazil) and close to Paraguay. Lamas et al. (2014) commented that H. hirsutum was recorded in Paraguay, but they could not confirm its presence based on material examined in collections and literature review. The other five specimens of this species were captured in Villalonga, south of Buenos Aires province (Fig. 1). This region is located south of the Monte ecoregion and the predominant land use is agricultural-livestock and the main crops are onion (Allium cepa L.) and lucerne (Medicago sativa L.) (Torretta et al. 2021). Four females were collected feeding on nectar from flowers of lucerne and one male from one flowerhead of yellow star-thistle (Centaurea solstitialis L.), a common exotic weed in this region. This site is more than 1,000 km from La Patquía (La Rioja), the previous locality from the Monte ecoregion where H. hirsutum was captured and represents the austral-most geographic record for Heterostylum. In summary, in this paper we increase to four the number of species of Heterostylum recorded from Argentina, expand the austral-most distribution record of the genus by more than 1,000 km and tentatively propose Diadasina distincta (Apidae: Emphorini) as a possible host for H. hirsutum.Published as part of Torretta, Juan P., Haedo, Joana P., Marrero, Hugo J. & Lamas, Carlos J. E., 2021, New austral-most records of the genus Heterostylum Macquart (Diptera Bombyiliidae) in Argentina, pp. 583-586 in Zootaxa 4990 (3) on page 585, DOI: 10.11646/zootaxa.4990.3.10, http://zenodo.org/record/502686
Voice Compression and Communications: Principles and Applications for Fixes and Wireless Channels
No full textUp-to-date, expert coverage of topics in wireless voice communications Voice communication is the most important facet of mobile radio service. Even when the predicted surge of wireless data and Internet services becomes a reality, voice will remain the most natural means of human communication. Voice Compression and Communications details issues in wireless voice communications and treats compression, channel coding, and wireless transmission as a joint subject. Part I covers background material, whereas Part II provides detailed information on both proprietary and standardized analysis-by-synthesis codecs, including the speech codecs of virtually all existing wireline-based and wireless systems. Parts III and IV discuss mainly research-based wideband, audio, as well as very low-rate schemes likely to find their way into future standards. Voice Compression and Communications describes fundamental concepts in a non-mathematical way early in the book for those with only a background knowledge of signal processing and communications. More advanced readers will find detailed discussions of theoretical principles, future concepts, and solutions to various specific wireless voice communications problems
Megachile (Sayapis) mendozana Cockerell 1907
No full text<i>Megachile</i> (<i>Sayapis</i>) <i>mendozana</i> Cockerell, 1907 <p>(Figs. 1–4)</p> <p> <i>Megachile cornuta</i> Smith, 1879: 78 (<i>non</i> Latreille 1805); Cockerell, 1905: 341</p> <p> <i>Megachile rhinoceros</i> Friese, 1906: 97 (<i>non</i> Mocsáry 1892); 1908: 68; Jörgensen, 1909: 215; Vachal, 1909: 15; Moure, 1943: 178.</p> <p> <i>Megachile mendozana</i> Cockerell, 1907: 50. Replacement name for <i>M</i>. <i>cornuta</i> Smith; Jörgensen, 1912: 128; Schrottky, 1909: 267; Cockerell, 1914; 428.</p> <p> <i>Megachile</i> (<i>Sayapis</i>) <i>mendozana</i> Mitchell, 1943: 664; Moure, 1943: 178.</p> <p> <i>Eumegachile</i> (<i>Sayapis</i>) <i>mendozana</i> Mitchell, 1980: 46.</p> <p> <i>Eumegachile</i> (<i>Sayapis</i>) <i>santiaguensis</i> Durante, 1996 (in Durante & Díaz, 1996): 334–336. <b>[New synonymy]</b></p> <p> <i>Megachile</i> (<i>Sayapis</i>) <i>santiaguensis</i> (Durante), Raw 2002: 34.</p> <p> <b>Material studied.</b> New records: ARGENTINA. Buenos Aires. Rivadavia, 1 male, Ea. Trébol Curá, J.P. Torretta & G. Cilla, XII-2006; Carlos Casares, 2 females, Ea. San Claudio, J.P. Torretta & G. Cilla, II-2007; 3 males and 1 female from nests, J.P. Torretta, XII-2010. Córdoba. Roca, 1 male, J.P. Torretta, G. Cilla & N. Montaldo, I-2007. La Pampa. Toay, Ea. Anquilóo, 1 male, J.P. Torretta, XI-2008; 5 females and 1 male, H.J. Marrero I-2009; 2 females, H.J. Marrero II-2009; 1 male, H.J. Marrero XII-2010.</p> <p> <b>Distribution.</b> In Argentina, this species is found in Buenos Aires, Catamarca, Chaco, Córdoba, La Pampa, La Rioja, Mendoza, Misiones, San Juan, Santa Fe, and Santiago del Estero (Fig. 1). It is also present in Paraguay (Raw 2007) and São Paulo, Brazil (Moure <i>et al</i>. 2007).</p> <p> <b>Comments.</b> All individuals that emerged from the trap-nests (1 female and 3 males) share morphological similarities that support the synonymy. Both sexes have black integument; wings hyaline; costal area, radial cell and distal margin of fore wing dark brown; tegula brown. Pilosity white or pale yellowish. Integument of the head generally coriaceous, small, deep and abundantly punctate, larger on basal area of clypeus. Scutum, scutellum, and axilla with large and abundant punctures. Metasoma with larger, slightly deep and abundant punctures; fifth tergum with irregular and close punctures. Moreover, the distributions of both entities exhibit a broad overlap in Argentina. This overlapping distribution also supports the synonymy proposed in this paper.</p> <p> <b>Biological observations. Nesting ecology</b>. A total of seven nests of <i>M</i>. <i>mendozana</i> were collected in traps. Five nests were gathered in January 2010, while the remaining two in March 2010. The length of the trap-nests used by females of <i>M</i>. <i>mendozana</i> were 233.4 ± 21.7 mm (range: 205–258) with apertures of 6.85 ± 0.69 mm (range: 6–8) in diameter. The nests contained from 2-12 cells (4.86 ± 3.29 cells; n= 34). Of the total cells, 20 larvae died during early stages of development and 10 post-defecting larvae were attacked by <i>Melittobia hawaiiensis</i> Perkins (Hymenoptera: Eulophidae) (Table 1).</p> <p> placement to removal of the traps. Nester associates in block are other <i>Megachile</i> species that occupied the same block.</p> <p>Block Nest Nesting Cells Adults emergence (date; position of Dead offspring Nesters associates in</p> <p> period (n) cell in nest) block female male larvae <i>Melitmum- tobia</i> mified attack</p> <p> Total 34 1 3 20 10 The females of <i>M</i>. <i>mendozana</i> construct cells that are separated from each other by partitions and are not surrounded by a leaf/petal/mud envelope (Figs. 2–3). These partitions are formed by small pieces of leaves not sealed to the trap-nest, followed by chewed plant material and earth and small pebbles (2–3 mm of thickness). All the nests were closured with masticated plant material and mud. Pollen masses were moist and sticky, homogenously mixed with nectar, occupying half or 2/5 of the cell volume (Figs. 2–3). The color of the nests provision varied according to the host plant (Figs. 2–3). The eggs were placed on the pollen masses (Fig. 2). Adults of <i>M</i>. <i>mendozana</i> hatched between 17 and 27 December 2010 (Table 1).</p> <p> <b>Pollen analysis.</b> In all cells analyzed, we found 8 pollen types (Fig. 4). Only grains type- <i>Carduus</i>, were present in all cells (62.1±29.4%), and in three cells pure pollen (100%) loads were found. Other pollen types found in various cells were type-Brassicaceae (21.3±16.1%, in 8 cells) and type-Lactuceae (7.5 ± 14.1%, in 5 cells). Pollen type- <i>Centaurea</i> was only found in two cells but in high percentages (39.2 and 57.2 %) each. The average percentage of Asteraceae pollen was 78.5 ± 28.6%.</p> <p> <b>Floral hosts.</b> Adults of <i>M</i>. <i>mendozana</i> were collected in flowers of the following plant species: <i>Baccharis pingraea</i>, <i>Carduus acanthoides</i>, <i>Centaurea solstitialis</i>, <i>Cirsium vulgare</i>, <i>Helianthus annuus</i>, and <i>Senecio pampeanus</i> (Asteraceae).</p>Published as part of <i>Torretta, Juan Pablo & Durante, Silvana Patricia, 2011, Nesting ecology of Megachile (Sayapis) mendozana Cockerell and its synonymy with Megachile (Sayapis) santiaguensis Durante (Hymenoptera: Megachilidae), pp. 63-68 in Zootaxa 3008</i> on pages 64-65, DOI: <a href="http://zenodo.org/record/278550">10.5281/zenodo.278550</a>
1973-10-25 Morehead State Concert and Lecture Series J.P. Donleavy
No full textRenowned author J.P. Donleavy speaks on the plight of an author and the methods to write, recorded on October 25, 1973
Entrainment and detrainment rates from the piv measurements at the top of laboratory analogs of stratocumulus and cumulus clouds
No full textWe analyze mixing at the top of laboratory analogs of convective clouds: stratocumulus and cumulus to investigate entrainment of environmental air into the cloud. We retrieve two components of air velocity using Particle Image Velocimetry technique. Suitable image processing allows to determine cloud–clear air interface. Using velocity differences between cloudy and clear sides of the interface we calculate entrainment / detrainment rates
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