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41.
FREDRIK PLEIJEL GREG W. ROUSE TOBIAS SUNDKVIST ARNE NYGREN 《Zoological Journal of the Linnean Society》2012,165(3):471-494
Phylogenetic analyses of molecular data (COI, 16SrDNA, 18SrDNA, and 28SrDNA) show that the hesionid genus Gyptis Marion & Bobretzky in Marion, 1874, and the tribe Gyptini Pleijel, 1998, are nonmonophyletic as currently delineated. We introduce the new tribe Amphidurini and the new genus Neogyptis to accommodate these new findings. Amphidurini is sister to Gyptini and Ophiodromini and includes Amphiduros Hartman, 1959, Amphiduropsis, Pleijel, 2001, Neogyptis gen. nov. , and, possibly, Parahesione Pettibone, 1956. Morphologically, Amphidurini can be separated from Gyptini by the distally, rather than subdistally, inserted ventral cirri, and Neogyptis by the combination of this feature, the presence of a median antenna, and a distal ring with papillae on the proboscis. We redescribe and transfer the four species Gyptis crypta Pleijel, 1993, Gyptis mediterranea Pleijel, 1993, Gyptis plurisetis Hilbig, 1992, and Gyptis rosea (Malm, 1874) from Gyptis to Neogyptis gen. nov. , and describe five new species from shallow waters in Belize, Hong Kong, off Vladivostok, and deep‐sea hydrothermal vents in the Lau Basin off Fiji. 相似文献
42.
Ultrastructure of spermiogenesis and spermatozoa of four Oriopsis species (Sabellinae, Sabellidae, Polychaeta) 总被引:1,自引:0,他引:1
GREG W. ROUSE 《Zoologica scripta》1992,21(4):363-379
The ultrastructure of sperm from four species of Oriopsis is described. Males of Oriopsis bicoloris produce sperm with an elongate nucleus divided into four rods, connected proximally, and four long mitochondria lying along the nucleus. The axoneme runs in the middle of the nuclear and mitochondria1 rods. Oriopsis brevicollaris males have sperm with an elongate nucleus and long midpiece comprised of four mitochondria wrapped around the axoneme. Males of O. mobilis have sperm with an elongate nucleus and long midpiece similar to that of O. brevicollaris , although the midpiece is much longer. Oriopsis dentata males havc sperm with a flattened head, similar to those of mammals, though the midpiece is simple and the axoneme free. The variability of reproductive mechanisms within the Polychaeta is discussed with reference to the elucidation of the function of various sperm morphologies. The implications for the taxonomy and systematics of Oriopsis , and the Sabellidae as a whole, are also discussed. It is concluded that Oriopsis is not monophyletic and examination of reproductive structures in other small sabellids is required. Study on reproduction in the type species, O. armandi , is needed to establish the reproductive method of Oriopsis and so allow revision of this genus. 相似文献
43.
The pay-off from superparasitism in the egg parasitoid Trissolcus basalis, in relation to patch defence 总被引:1,自引:0,他引:1
1. In species such as quasi-gregarious egg parasitoids, which exploit defendable patches, the fitness pay-off from superparasitism is an important factor in considering the evolution of patch defence and optimal patch defence strategies.
2. When oviposition in a previously parasitized host has a non-zero fitness pay-off, competing parasitoids are not only able to diminish the future value of a patch to other females by depleting unparasitized hosts, but also devalue the previous investment of other females in the patch by superparasitizing.
3. In Trissolcus basalis , an egg parasitoid of pentatomid bugs, the fitness pay-off from superparasitism is higher than 0.5 when the time interval between ovipositions is less than 3 h, suggesting that defending a previous investment will be an important component of patch defence behaviour.
4. The data suggest a mechanism for the high early pay-off, which involves the superparasitizing female adjusting the sex ratio of its offspring in favour of males. Males develop more quickly than females and thus may have a competitive advantage. 相似文献
2. When oviposition in a previously parasitized host has a non-zero fitness pay-off, competing parasitoids are not only able to diminish the future value of a patch to other females by depleting unparasitized hosts, but also devalue the previous investment of other females in the patch by superparasitizing.
3. In Trissolcus basalis , an egg parasitoid of pentatomid bugs, the fitness pay-off from superparasitism is higher than 0.5 when the time interval between ovipositions is less than 3 h, suggesting that defending a previous investment will be an important component of patch defence behaviour.
4. The data suggest a mechanism for the high early pay-off, which involves the superparasitizing female adjusting the sex ratio of its offspring in favour of males. Males develop more quickly than females and thus may have a competitive advantage. 相似文献
44.
A cladistic analysis of Siboglinidae Caullery, 1914 (Polychaeta, Annelida): formerly the phyla Pogonophora and Vestimentifera 总被引:7,自引:0,他引:7
GREG W. ROUSE 《Zoological Journal of the Linnean Society》2001,132(1):55-80
It has been proposed in recent years that the phyla Pogonophora and Vestimentifera are a derived clade of polychaete annelids. It has also been proposed that if this clade belongs among polychaetes, then the taxon name Pogonophora is misleading and should revert to a name first formulated for the group, Siboglinidae Caullery, 1914. This recommendation is adopted in this paper, and a cladistic study using terminals of 'generic' rank in the former Pogonophora (including Vestimentifera) is undertaken. The purpose of this is to assess which taxon names should now be used for clades within Siboglinidae, and to provide a revised taxonomy, based on phylogenetic principles. Another major aim is to assess the position of the vestimentiferan clade within Siboglinidae. The results show that Vestimentifera is the sister group to Sclerolinum, and this clade is then sister group to Frenulata, i.e. the remaining Siboglinidae. The results suggest that all taxa within Siboglinidae that are not genera or species are redundant, except for the following: Siboglinidae is defined as the first polychaete, and all its descendants, to have an gut occluded by expanded endoderm filled with chemoautotrophic bacteria, as seen in the holotype of Riftia pachyptila Jones, 1981. Monilifera can be defined based on apomorphy-based system such that it is the first siboglinid, and all its descendants, to have rings of chaetae (uncini) in the opisthosoma, as seen in the holotype of Sclerolinum magdalenae Southward, 1972. Vestimentifera can be denned as the first siboglinid and all its descendants to have a vestimentum as seen in the holotype of Riftia pachyptia. Frenulata is defined as the siboglinid, and all its descendants, to have a mid-trunk girdle, as seen in the holotype of Siboglinum weberi Caullery, 1914. The taxa of generic rank are not defined here since their monophyly was not investigated. 相似文献
45.
Lessons learned in developing community mental health care
in Latin American and Caribbean countries
DENISE RAZZOUK GUILHERME GREG��RIO RENATO ANTUNES JAIR DE JESUS MARI 《World psychiatry》2012,11(3):191-195
This paper summarizes the findings for the Latin American and Caribbean
countries of the WPA Task Force on Steps, Obstacles and Mistakes to Avoid
in the Implementation of Community Mental Health Care. It presents an overview
of the provision of mental health services in the region; describes key experiences
in Argentina, Belize, Brazil, Chile, Cuba, Jamaica and Mexico; and discusses
the lessons learned in developing community mental health care. 相似文献
46.
GREG DOWNEY 《American anthropologist》2008,110(2):204-213
ABSTRACT Imitation plays a crucial role in apprenticeship in the Afro-Brazilian performance genre capoeira, as in many skills across cultures. In this article, I examine the interactional dynamics of imitative pedagogy in capoeira to better understand physical education as a form of bodily enculturation. The ability to learn through imitation is widely considered a hallmark of our species. Imitative ability, however, is a social accomplishment rather than a capacity of the learner in isolation. Human models often provide assistance to novices seeking to imitate, including a variety of forms of what educational theorists call "scaffolding," which are astutely structured to a novice's ability, perceptions, and even neurology. Scaffolding techniques vary. I here examine how instructors reduce students' degrees of movement freedom, reorient their model in perceptual space, and parse complex sequences into component gestures. Close analysis of pedagogical interaction highlights the divergence between forms of instruction and practical skills being taught. 相似文献
47.
JASON M. GILSDORF KURT C. VERCAUTEREN SCOTT E. HYGNSTROM W. DAVID WALTER JUSTIN R. BONER GREG M. CLEMENTS 《The Journal of wildlife management》2008,72(5):1241-1246
Abstract: We designed and developed a vehicle-mounted very high frequency-based telemetry system that integrated an on-board antenna, receiver, electronic compass, Global Positioning System, computer, and Geographic Information System. The system allows users to accurately and quickly obtain fixes, estimate and confirm locations of radiomarked animals, and immediately record data into an electronic spreadsheet or database. The total cost of materials to build the system was $7,349 (United States currency). Mean error angle of 2.63 ± 12.1° (SD; range = −33.7–42.2°) and mean location error distance of 128 ± 91.3 m (SD; range = 0–408 m) suggested precision and accuracy of our system were comparable to other reported systems. Mean time to record 5 bearings/test transmitter was 6.28 ± 0.24 minutes (SE), which is the most efficient system reported to locate animals in the field. Vehicle-mounted telemetry systems like ours provide additional value to studies that involve tracking highly mobile species because investigators need not take bearings from established receiving stations and because investigators can immediately recognize bounced signals and take additional bearings and optimize accuracy of location estimates. 相似文献
48.
ERIC G. LAMB SUKKYUN HAN BRIAN D. LANOIL GREG H. R. HENRY MARTIN E. BRUMMELL SAMIRAN BANERJEE STEVEN D. SICILIANO 《Global Change Biology》2011,17(10):3187-3194
We evaluated above‐ and belowground ecosystem changes in a 16 year, combined fertilization and warming experiment in a High Arctic tundra deciduous shrub heath (Alexandra Fiord, Ellesmere Island, NU, Canada). Soil emissions of the three key greenhouse gases (GHGs) (carbon dioxide, methane, and nitrous oxide) were measured in mid‐July 2009 using soil respiration chambers attached to a FTIR system. Soil chemical and biochemical properties including Q10 values for CO2, CH4, and N2O, Bacteria and Archaea assemblage composition, and the diversity and prevalence of key nitrogen cycling genes including bacterial amoA, crenarchaeal amoA, and nosZ were measured. Warming and fertilization caused strong increases in plant community cover and height but had limited effects on GHG fluxes and no substantial effect on soil chemistry or biochemistry. Similarly, there was a surprising lack of directional shifts in the soil microbial community as a whole or any change at all in microbial functional groups associated with CH4 consumption or N2O cycling in any treatment. Thus, it appears that while warming and increased nutrient availability have strongly affected the plant community over the last 16 years, the belowground ecosystem has not yet responded. This resistance of the soil ecosystem has resulted in limited changes in GHG fluxes in response to the experimental treatments. 相似文献
49.
GREG DOWNEY 《American anthropologist》2005,107(1):156-157
50.
Increasing surface levels of UV-B resulting from stratospheric ozone reduction directly affect tropospheric photochemistry. There may also be indirect tropospheric effects due to changes in emission of organic compounds from vegetation. We treated woody and herbaceous isoprene-emitting species in the field with supplemental UV-B simulating 30% ozone depletion. For Quercus gambelii, photosynthesis and isoprene emission were significantly greater in elevated UV-B treatments when expressed on a leaf area basis, but not on a leaf mass basis. Leaves of Mucuna pruriens, however, showed no significant differences in photosynthesis or isoprene emission between treatments, nor when exposed for 45 min to acute high levels of UV-B. Elevated UV-B during growth did not elicit significant isoprene emission from Acer platanoides, a non-emitting species. Other potential UV-B effects, such as changes in leaf area or species composition, which may influence regional isoprene emissions, should be examined. 相似文献