Changes in the vertical distribution of capelin (Mallotus villosus) off Newfoundland     

Mowbray  Frances K. 《ICES Journal of Marine Science》2002,59(5):942-949

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Rotation rate of high-latitude sunspots     

Frances Tang 《Solar physics》1981,69(2):399-404

Rotation rate of 19 high latitude (28–44°) short-lived sunspots collected in 1978–1979 are compared with Newton and Nunn's (1951) recurrent spots rate. To reduce the effect of proper motion in spots of new regions, our measurements start only when the spots have matured or very nearly so. Compared with the expression = 14.38–2.96 sin² derived from 1934–44 data by Newton and Nunn, our results show a slightly lower differential rotation in the 28–40° zone. They are in better agreement with the Greenwich average results of the five solar cycles beginning 1878: = 14.37–2.60 sin² .Hale Observatories are operated jointly by the Carnegie Institution of Washington and the California Institute of Technology.  相似文献   

Filament Disappearances During the Period of September 1991 through September 1994     

Haimin Wang  Arkadiusz E. Komenda  Frances Tang  Hal Zirin 《Solar physics》1998,178(1):109-117

Continuous full-disk H images recorded by the Big Bear Solar Observatory (BBSO) from 1 September 1991 to 19 September 1994 (the first three years of Yohkoh mission) were digitized and analyzed. The data set consists of nearly 10000 H images, one every half hour for the period when the BBSO was observing. Two statistical studies of the disappearing solar filaments based on this set of data are made: (1) The disk latitude distribution of all larger disappearing filaments with a minimum length of 70 arc sec, including the time of their disappearance. Of the 1095 such filaments, 439 disappeared during our continuous observations, 314 disappeared during the BBSO night gap, 162 disappeared during data gap (more than 94 hours) and 180 rotated beyond the west limb. If we plot latitudes as a function of time for all these disappeared filaments, it shows a uniform distribution in latitude. However, if we plot the distribution of larger disappeared filaments (200 arc sec or above), then the butterfly trend appears – position of filaments tends to drift to lower latitude as solar activity decreases. (2) The disk distribution of all detectable disappearing filaments, large and small, for the 9-months period, January 1994 to September 1994. We find that the size distribution of 351 collected disappeared filaments follows a power law with a power index of –1.40.  相似文献   

Towards an expanded model of curriculum development and diffusion in education     

Frances Slater  Brian Spicer 《Geoforum》1979,10(3):243-249

The general model of the curriculum development process has been widely accepted as a satisfactory view of the process at work and of how the process might be made to work in practice. Such a model ignores the human element. The paper expands the general model so as to include the social interaction and interpersonal dynamics dimension of curriculum change. Concepts in diffusion theory and behavioural geography provide a perspective for building into the curriculum process views of it as a social system akin in some respects to a feudal society. The expanded model includes consideration of the influence of the social, personal, psychological and attitudinal traits of those engaged in curriculum development. The spatial pattern likely to be created by the model provokes questions about the best management of the diffusion process.  相似文献   

Seasonal and Spatial Variations in Fish and Macroinvertebrate Communities of Oyster and Adjacent Habitats in a Mississippi Estuary     

Virginia R. Shervette  Frances Gelwick 《Estuaries and Coasts》2008,31(3):584-596

In Grand Bay National Estuarine Research Reserve (Grand Bay NERR), Mississippi, we used quantitative drop sampling in three common shallow estuarine habitats—low profile oyster reef (oyster), vegetated marsh edge (VME), and nonvegetated bottom (NVB)—to address the dearth in research comparing nekton utilization of oyster relative to adjacent habitats. The three habitats were sampled at two distinct marsh complexes within Grand Bay NERR. We collected a total of 633 individual fishes representing 41 taxa in 22 families. The most diverse fish family was Gobiidae (seven species) followed by Blennidae and Poeciliidae (three species each). We collected a total of 2,734 invertebrates representing 24 taxa in 11 families. The most diverse invertebrate family was Xanthidae (six species) followed by Palaemonidae (five species). We used ordination techniques to examine variation in species relative abundance among habitats, seasons, and sampling areas, and to identify environmental gradients correlated with species relative abundances. Our resulted indicated that oyster provided a similarly complex and important function as the adjacent VME. We documented three basic trends related to the importance of oyster and VME habitats: 1) Oyster and VME provide habitat for significantly more species relative to NVB, 2) Oyster and VME provide habitat for rare species, and 3) Several species collected across multiple habitats occurred at higher abundances in oyster or VME habitat. We also found that salinity, temperature, and depth were associated with seasonal and spatial shifts in nekton communities. Lastly, we found that the relative location of the two marsh complexes we studied within the context of the whole estuary may also explain some of the temporal and spatial differences in communities. We conclude that oyster habitat supported a temporally diverse and spatially distinct nekton community and deserves further attention in research and estuarine conservation efforts.  相似文献   

Biophysical controls on dissolved organic carbon concentrations of Alaskan coastal temperate rainforest streams     

David V. D’Amore  Rick T. Edwards  Frances E. Biles 《Aquatic Sciences - Research Across Boundaries》2016,78(2):381-393

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Metal tissue levels in Steller sea lion (Eumetopias jubatus) pups     

Holmes AL  Wise SS  Goertz CE  Dunn JL  Gulland FM  Gelatt T  Beckmen KB  Burek K  Atkinson S  Bozza M  Taylor R  Zheng T  Zhang Y  Aboueissa AM  Wise JP 《Marine pollution bulletin》2008,56(8):1416-1421

The endangered Western population of the Steller sea lion declined for three decades for uncertain reasons. We present baseline data of metal concentrations in pups as a first step towards investigating the potential threat of developmental exposures to contaminants. Seven metals were investigated: arsenic, cadmium, silver, aluminum, mercury, lead and vanadium. Vanadium was detected in only a single blubber sample. Mercury appears to be the most toxicologically significant metal with concentrations in the liver well above the current action level for mercury in fish. The concentrations of aluminum, arsenic, silver, cadmium and lead were present in one-fourth to two-thirds of all samples and were at either comparable or below concentrations previously reported. Neither gender nor region had a significant effect on metal burdens. Future work should consider metal concentrations in juveniles and adults and toxicological studies need to be performed to begin to assess the toxicity of these metals.  相似文献   

In a PICL: The sedimentary deposits and facies of perennially ice‐covered lakes     

Frances Rivera‐Hernandez  Dawn Y. Sumner  Tyler J. Mackey  Ian Hawes  Dale T. Andersen 《Sedimentology》2019,66(3):917-939

Perennially ice‐covered lakes can have significantly different facies than open‐water lakes because sediment is transported onto the ice, where it accumulates, and sand grains preferentially melt through to be deposited on the lake floor. To characterize the facies in these lakes, sedimentary deposits from five Antarctic perennially ice‐covered lakes were described using lake‐bottom observations, underwater video and images, and sediment cores. One lake was dominated by laminated microbial mats and mud (derived from an abutting glacier), with disseminated sand and rare gravel. The other four lakes were dominated by laminated microbial mats and moderately well to moderately sorted medium to very coarse sand with sparse granules and pebbles; they contained minor interstitial or laminated mud (derived from streams and abutting glaciers). The sand was disseminated or localized in mounds and 1 m to more than 10 m long elongate ridges. Mounds were centimetres to metres in diameter; conical, elongate or round in shape; and isolated or deposited near or on top of one another. Sand layers in the mounds had normal, inverse, or no grading. Nine mixed mud and sand facies were defined for perennially ice‐covered lakes based on the relative proportion of mud to sand and the style of sand deposition. While perennially ice‐covered lake facies overlap with other ice‐influenced lakes and glaciomarine facies, they are characterized by a paucity of grains coarser than granules, a narrow range in sand grain sizes, and inverse grading in the sand mounds. These facies can be used to infer changes in ice cover through time and to identify perennially ice‐covered lakes in the rock record. Ancient perennially ice‐covered lakes are expected on Earth and Mars, and their characterization will provide new insights into past climatic conditions and habitability.  相似文献   

Doing interdisciplinarity: motivation and collaboration in research for sustainable agriculture in the UK     

Frances Harris  Fergus Lyon  Sarah Clarke 《Area》2009,41(4):374-384

This paper studies knowledge production in complex, collaborative research projects that brought together academics from different disciplines, research users and agricultural businesses. It takes a comparative approach, studying the interactions within interdisciplinary research teams from ten case studies, considering the process of collaboration from initial idea through to publication. The research developed a typology of participants in these projects, and identified the motivations and challenges of each. Our results analyse the process of research teams coming together and the relationships that are built up during the research. A particular challenge identified was the building of cooperation and trust. This issue is explored alongside issues of communication, methodology, data analysis and the process of drawing and publicising conclusions.  相似文献   

Rotating neutron stars: an invariant comparison of approximate and numerical space–time models     

Emanuele Berti  Frances White  Asimina Maniopoulou  Marco Bruni 《Monthly notices of the Royal Astronomical Society》2005,358(3):923-938

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