After the appearance of a portable Kodak cine camera in 1923, home moving making grew steadily in popularity in the years
leading up to and following World War II. Cine enthusiasts, particularly in the pre-war period, tended to be male, white and
middle class, although exceptions exist, and they tended to travel with their cameras much as earlier generations had documented
their experiences in written and artistic form. Despite their amateur status, they were often very professional in their approach
to cinematography and they produced material for a range of domestic and public audiences on varied topics and in different
genres. Specialist publications and the rapid growth of local amateur film societies fostered the rise of an active non-professional
film movement; the result is a highly distinctive although neglected component of film history. With reference to materials
held at the North West Film Archives in Manchester, England, this discussion considers the rise of non-professional filmmaking
at the regional level during the decades before and after the second world war. Making and showing home movies is placed within
various socio-cultural contexts. The imagery discloses much about visual practice, including filmmakers' perceptions and their
relationships with different kinds of subject matter. The making of holiday footage, in Mediterranean settings, and its subsequent
screening in domestic or public places, connects with broader issues of visualization, social practice and leisure-related
consumption.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
Acoustic backscatter from an active sonar system over a range of six frequencies between 265 kHz and 3 MHz in the tidally
dominated Damariscotta River estuary, Maine, United States, revealed that the major emergence event of the night commenced
on the first tidal deceleration after dark (3.5–4 h after local slack), irrespective of flow direction. Emergence traps identified
the mysid shrimp,Neomysis americana, as the dominant migrator. Water-column-integrated, acoustically estimated biovolume at our 10-m deep study location increased
by a factor of about 6 during these large events, entirely dominating the holoplanktonic contribution and likely being a major
component in benthic-pelagic coupling. Application of the same algorithm used to locate this nighttime emergence revealed
a parallel but considerably smaller daytime emergence event near the same phase of the tide. Daytime trap samples failed to
recover the organisms responsible, but transmissometry rejected the alternative hypothesis that we observed resuspension events.
We suspect, but have yet only weak evidence, that animals emerging in daylight are copepods rather than mysids. 相似文献
Hydrous pyrolysis experiments were performed on the Ghareb Formation (Upper Cretaceous, Jordan), a carbonate- and organic-rich (TOC 19.6%) source rock, using a temperature range of 200 to 360°C (72 h). The original sediment contains only low amounts of carbazoles, (maximum 2.2 μg/g bitumen for 1-methylcarbazole). With increasing thermal maturation, intense generation begins at temperatures only in excess of 300°C, reaching a maximum at 360°C. Likewise, during natural maturation, generation occurs at later stages of maturity (e.g. for Tithonian source rocks at >0.81% Rr and for Posidonia Shale at >0.88% Rr). Some isomeric changes during hydrous pyrolysis do not resemble those in nature whereas others do. The relative abundances of selected C1- and C2-alkylcarbazoles on ternary diagrams reveal differences, whereas the benzo[a]carbazole/benzo[a]carbazole+benzo[c]carbazole ratio is closely similar. The latter result supports the contention that maturation plays a key role in controlling carbazole distributions in source rocks. However, the results for alkylcarbazoles, especially the C2-carbazoles, are not easy to interpret. 相似文献
Brown shrimp (Farfantepenaeus aztecus) are an important commercial aquatic species experiencing loss of inshore marsh nursery habitat in coastal Louisiana. To
study inshore brown shrimp movements and identify aspects of essential habitat important for sustaining brown shrimp populations,
we collected juvenile brown shrimp in April and May 2000, the time of annual maximum brown shrimp abundance, in a small 1-km2 marsh area on the central Louisiana coast. Drop sampling showed average shrimp densities of 1.6–2.4 m−2 in shallow marsh ponds and seining indicated lower densities of 0.5–0.9 m−2 in nearby shallow channel and open bay sites. Smaller shrimp (< 50 mm) fed disproportionately on benthic diatoms and small
harpacticoid copepods, while large shrimp fed more frequently on larger-bodied amphipods and tanaids. We developed novel chemical
approaches to estimate patterns of shrimp residency and movement using carbon and nitrogen stable isotopic determinations.
Resident shrimp had isotopic values similar to average foods and showed consistent isotopic spacings between fast and slow
turnover tissues. Residency was highest (47–55%) in ponds and shallow channel habitats and much less in open bays and deep
channels (4–27%). There was sparse evidence for dietary specialization among individull shrimp. The results support the view
that small 10–20 mm postlarval and juvenile brown shrimp arriving in estuaries from offshore waters continue movement through
sub-optimal habitats (deep channels and open bays), but exhibit much less movement once an optimal habitat (marsh ponds or
shallow channel margins) is reached. This study also indicated that combining estimates of shrimp densities, residency, growth
rate, and mortality allows evaluation of the importance of different habitat types for shrimp production. Shallow ponds that
in many ways resemble fertile aquaculture ponds appear to be hot spots for brown shrimp production, and coastal preservation
and restoration efforts should focus on these areas as important for sustaining shrimp fisheries. 相似文献
We describe the interplanetary coronal mass ejections (ICMEs) that occurred as a result of a series of solar flares and eruptions
from 4 to 8 November 2004. Two ICMEs/magnetic clouds occurring from these events had opposite magnetic orientations. This
was despite the fact that the major flares related to these events occurred within the same active region that maintained
the same magnetic configuration. The solar events include a wide array of activities: flares, trans-equatorial coronal loop
disappearance and reformation, trans-equatorial filament eruption, and coronal hole interaction. The first major ICME/magnetic
cloud was predominantly related to the active region 10696 eruption. The second major ICME/magnetic cloud was found to be
consistent with the magnetic orientation of an erupting trans-equatorial filament or else a rotation of 160° of a flux rope
in the active region. We discuss these possibilities and emphasize the importance of understanding the magnetic evolution
of the solar source region before we can begin to predict geoeffective events with any accuracy. 相似文献
Understanding the effects of microbiota on mineral alteration requires the ability to recognize evidence of bacteria-promoted dissolution on mineral surfaces. Although siderophores are known to promote mineral dissolution, their effects on mineral surfaces are not well known. We have utilized atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Mirau vertical scanning interferometry (VSI) to investigate surfaces after incubation with the siderophore desferrioxamine-B mesylate (DFAM) and under colonies of bacteria. Iron-silicate glass planchets chemically similar to hornblende were incubated in buffered growth medium with siderophore-producing bacteria (Bacillus sp.) for 46 days with parallel abiotic experiments conducted with and without 240 μM DFAM, with and without 0.01 g l− 1 of microbially produced extracellular polysaccharides (EPS, alginate or xanthan gum). Some glass planchets were protected by dialysis tubing from direct contact with the EPS. Weekly sampling and analysis of all filtered sample solutions showed negligible Fe and Al release in the control experiments and significant release of Fe and Al in the presence of DFAM, with negligible changes in pH. Concentration of Fe in the filtered solutions after incubation with bacteria was below detection, consistent with uptake of Fe by cells. Release of Fe, Al, and Si in control, xanthan-only, and alginate-only experiments was negligible. Release of these elements was enhanced in all experiments containing DFAM, and greatest in alginate + DFAM experiments.
AFM and VSI analyses reveal widespread, small etch pits and greater root mean squared roughness on siderophore-exposed surfaces and fewer, localized, larger etch pits on bacteria-exposed surfaces. This is the first documented case of etch pit development during siderophore-promoted dissolution. Roughness was not affected by the growth medium, alginate, or xanthan gum alone. The roughness trends among samples correlate with trends in Fe depletion documented by XPS. Enhanced dissolution and roughness cannot be attributed to direct contact with EPS because no significant chemical or physical differences were observed between surfaces directly exposed to EPS and those protected by dialysis tubing. Acetate released from the EPS may have enhanced the siderophore-promoted dissolution. Siderophores produced by Bacillus sp. may be responsible for some of the ‘biopits.’ The difference in size and distribution of the biopits may be related to colonization. 相似文献
Sediment from two deep boreholes (∼400 m) approximately 90 km apart in southern Bangladesh was analyzed by X-ray absorption spectroscopy (XAS), total chemical analyses, chemical extractions, and electron probe microanalysis to establish the importance of authigenic pyrite as a sink for arsenic in the Bengal Basin. Authigenic framboidal and massive pyrite (median values 1500 and 3200 ppm As, respectively), is the principal arsenic residence in sediment from both boreholes. Although pyrite is dominant, ferric oxyhydroxides and secondary iron phases contain a large fraction of the sediment-bound arsenic between approximately 20 and 100 m, which is the depth range of wells containing the greatest amount of dissolved arsenic. The lack of pyrite in this interval is attributed to rapid sediment deposition and a low sulfur flux from riverine and atmospheric sources. The ability of deeper aquifers (>150 m) to produce ground water with low dissolved arsenic in southern Bangladesh reflects adequate sulfur supplies and sufficient time to redistribute the arsenic into pyrite during diagenesis. 相似文献