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291.
Jae Hac Ko Timothy G. Townsend Hwidong Kim 《Journal of Material Cycles and Waste Management》2012,14(3):162-168
To increase the moisture content of waste disposed in a bioreactor landfill, it is critical to secure the moisture source. In this study, industrial wastewater was evaluated as a potential moisture source for a bioreactor landfill with respect to the impact on methane generation. Industrial wastewater samples were collected from fishery, brewery and dairy industries. These samples were tested for basic water chemistry parameters, heavy metals, and methane generation using the regular and modified biochemical methane potential (BMP) assays. Despite high sodium and total phosphate concentrations in the fishery wastewater, a significant methane yield was observed (0.313?m3 CH4/kg COD). However, a relatively large amount of fishery wastewater added at the phase of methane generation acceleration adversely affected microbial activity. Samples from the brewery and dairy wastewater did not indicate significant inhibitory effects on methane generation in either the regular or the modified BMP assay. This study demonstrates the utility of wastewater as an alternative to traditional moisture sources when used to enhance methane production in a bioreactor landfill. 相似文献
292.
Adam J. Siegel M. Kim Fondrk Gro V. Amdam Robert E. Page Jr. 《Behavioral ecology and sociobiology》2013,67(10):1623-1632
Honey bee workers exhibit an age-based division of labor (temporal polyethism, DOL). Younger bees transition through sets of tasks within the nest; older bees forage outside. Components of temporal polyethism remain unrevealed. Here, we investigate the timing and pattern of pre-foraging behavior in distinct strains of bees to (1) determine if a general pattern of temporal DOL exists in honey bees, (2) to demonstrate a direct genetic impact on temporal pacing, and (3) to further elucidate the mechanisms controlling foraging initiation. Honey bees selected for differences in stored pollen demonstrate consistent differences in foraging initiation age. Those selected for increased pollen storage (high pollen hoarding strain, HSBs) initiate foraging earlier in life than those selected for decreased pollen storage (low pollen hoarding strain, LSBs). We found that HSBs both initiate and terminate individual pre-foraging tasks earlier than LSBs when housed in a common hive environment. Unselected commercial bees (wild type) generally demonstrated intermediate behavioral timing. There were few differences between genotypes for the proportion of pre-foraging effort dedicated to individual tasks, though total pre-foraging effort differences differed dramatically. This demonstrates that behavioral pacing can be accelerated or slowed, but the pattern of behavior is not fundamentally altered, suggesting a general pattern of temporal behavior in honey bees. This also demonstrates direct genetic control of temporal pacing. Finally, our results suggest that earlier HSB protein (pollen) consumption termination compared to LSBs may contribute to an earlier decline in hemolymph vitellogenin protein titers, which would explain their earlier onset of foraging. 相似文献
293.
Sang Soo Lee Samy A.M. Abd El-Azeem Jung Eun Lim Anushka Upamali Rajapaksha Kwon-Rae Kim Young Han Lee 《Chemistry and Ecology》2013,29(6):501-510
Addition of plant residue into soils improves soil physiochemical properties and its fertility. Rapeseed residue is an emerging N source to paddy soils via rice-rape double-cropping practice. The objective of this study was to evaluate the effects of rapeseed residue and eggshell waste on chemical changes and enzyme activity in the rice paddy soil. The powdered eggshells at 0, 1, 3, and 5% were applied once to 7.0 kg paddy repacked soils in each pot treated with the rapeseed residue or the conventional N, P, and K fertilisers. Eight rice seedlings (Oriza sativa L. cv. Ilmibyeo) (40 days after sowing) were transplanted to the treated each pot. The contents of total C (TC) and N (TN), and organic matter (OM) were significantly increased in soils treated with the rapeseed residue compared to the N, P, and K fertilisers. With the addition of eggshell containing ~92% CaCO3, a considerable increase of soil pH was observed in soils treated with the rapeseed residue and the N, P, and K fertilisers, compared to the untreated soil. Activities of β-glucosidase, urease, and arylsulfatase enzymes were higher in soils treated with the rapeseed residue than soils treated with the N, P, and K fertilisers. The eggshell additions at 1, 3, and 5% into soils treated with the rapeseed residue increased enzyme activity mainly resulting from N mineralisation, whereas no change in enzyme activity was observed in the soils treated with the NPK fertiliser. The combined use of the rapeseed residue and the eggshells can be beneficial to improve soil environment. 相似文献
294.
Total concentrations of Cr, Ni, Cu, Zn, Cd and Pb in surface sediments were determined to investigate the regional trends
of heavy metal contamination in 11 coastal areas in Korea. Enrichment factor (EF) of heavy metals was calculated by comparing
the level of their regional background. The averages of EF values in study areas were 0.99 for Cr, 1.05 for Ni, 4.23 for Cu,
1.80 for Zn, 3.92 for Cd and 1.54 for Pb, respectively. Dilute HCl extractions were useful to deduce the anthropogenic sources
of heavy metals and the 1 M HCl extractable fractions of each metal varied from 0.3 to 37.3% for Cr, 1.9 to 66.3% for Ni,
4.2 to 92.9% for Cu, 7.1 to 99.7% for Zn, 10.9 to 98.9% for Cd and 15.0 to 99.1% for Pb. Comparing 1 M HCl extractable fraction
to total concentration, large portions of Cu, Zn, Cd and Pb were present as potentially bioavailable fractions from anthropogenic
input and were significantly correlated with their EF values showing r > 0.68. 相似文献
295.
Marianne Robert Laurent Dagorn Jean Louis Deneubourg David Itano Kim Holland 《Marine Biology》2012,159(4):907-914
Several lines of evidence indicate that aggregations of yellowfin tuna associated with floating objects are more frequently
composed of small animals than larger ones. Also, the diet of small yellowfin tuna caught at anchored fish aggregating devices
(FADs) around Oahu, Hawaii, was found to shift quite rapidly when these fish reached approximately 50 cm FL. In order to test
for ontogenetic changes in aggregation behavior, we tagged and released two distinct size classes of yellowfin tuna in an
array of anchored FADs around Oahu, Hawaii. Twenty-four yellowfin tuna 30–39 cm FL and 16 yellowfin tuna 63–83 cm FL were
tagged with acoustic transmitters and released near anchored FADs equipped with automated acoustic receivers. Fish in the
smaller size class stayed about 2.5 times longer at individual FADs than the larger fish (mean 4.05 days vs. 1.65 days) and
displayed larger horizontal movements within the array. However, the durations of unassociated phases, residence times in
the entire FAD array, percentage of time spent associated with FADs and numbers of movements between FADs did not show any
difference between the two size groups. The observed size-dependent behavior is discussed in terms of physiological abilities,
diet segregation and anti-predator behavior. 相似文献
296.
Tommy Kristensen Anders Isberg Nielsen Anders Isak J?rgensen Kim N. Mouritsen Henrik Glenner Jens T. Christensen J?rgen Lützen Jens T. H?eg 《Marine Biology》2012,159(9):2015-2023
Male crabs infected by parasitic barnacles (Rhizocephala) are known to be morphologically feminized. Here, we investigate morphological chances in green crabs, Carcinus maenas, induced by the parasitic barnacle Sacculina carcini. Infected males acquire a broader, longer and segmented abdomen, fringed with marginal setae. Copulatory appendages and pereopods are reduced in length, and the chelae become smaller. The feminization show great individual variation. Males with scars from lost externae, the parasites reproductive organ situated under the abdomen, are less modified than males carrying an externa, and the feminization is more pronounced in smaller than in larger males. No super-feminization is evident in female crabs that remain morphologically unaffected by infection. The protective value of a parasitically induced enlargement of the male abdomen may constitute an adaptation that increases parasite longevity. The additional effects on male morphology are viewed as pleiotropic side effects of the main adaptive value of enlarging the abdomen. 相似文献
297.
We equipped individual tiger (Galeocerdo cuvier Péron and Lesueur, 1822) and Galapagos (Carcharhinus galapagensis Snodgrass and Heller, 1905) sharks with both acoustic and satellite transmitters to quantify their long-term movements in
the Papahanaumokuakea Marine National Monument (Northwestern Hawaiian Islands). Tiger sharks exhibited two broad patterns
of behavior. Some individuals were detected at French Frigate Shoals (FFS) year round, whereas others visited FFS atoll in
summer to forage on fledging albatross, then swam thousands of kilometers along the Hawaiian chain, or out into open ocean
to the North Pacific transition zone chlorophyll front, before returning to FFS in subsequent years. These patterns suggest
tiger sharks may use cognitive maps to navigate between distant foraging areas. Different patterns of spatial behavior may
arise because cognitive maps are built up through individual exploration, and each tiger shark learns a unique combination
of foraging sites. Galapagos shark detections were all associated with FFS, suggesting these sharks may be more resident around
oceanic islands. Both Galapagos and tiger sharks primarily used the mixed layer (<100 m depth) and made occasional deeper
dives through the thermocline down to 680 m. Results show reef-associated sharks utilize a wide variety of habitats ranging
from shallow atoll lagoons to deep reefs and open ocean and may provide important trophic links between these habitats. 相似文献
298.
Parrotfishes can be significant bioeroders and sediment producers on coral reefs. We quantified the bioerosion rates of two
similarly sized Hawaiian parrotfishes with two different feeding modes (Scarus rubroviolaceus—a scraper and Chlorurus perspicillatus—an excavator). The results showed that feeding modes did not affect bioerosion rates but that bioerosion rates were size
dependent, with largest individuals (S. rubroviolaceus 45–54 cm FL) bioeroding up to 380 ± 67 kg ind−1 year−1. The size for onset of bioerosion capabilities for both species was 15 cm. Grazing by the two species consumed 60% of the
carbonate production of the fore reef area, suggesting that large parrotfishes in Hawaii are ecologically important bioeroders.
As individual large S. rubroviolaceus contributed disproportionately more to bioerosion and sediment production than the equivalent biomass of smaller conspecifics,
management strategies designed to retain normal reef bioerosion rates should seek to preserve the historical size structure
of S. rubroviolaceus populations and to especially protect the larger size classes. 相似文献
299.
Hwang SJ Kim HS Park JH Kim BH 《Journal of environmental biology / Academy of Environmental Biology, India》2010,31(4):483-488
We compared filtering rates (FR) and mortalities between freshwater filter-feeding bivalve Corbicula leana acclimatized (AM) and non-acclimatized (NAM) to an cyanobacterial bloom (mainly Microcystis aeruginosa) over seven days. Both mussel populations were simultaneously stocked into mesocosms constructed in littoral zones of a eutrophic lake at a density of 740 ind. m(-2) for 16 days. NAMs decreased the concentration of chlorophyll-a 50% less than AMs. For the first seven days, the FRs (0.46-0.61) and mortality rate (slope = -30.2, r = -0.95) of NAMs were higher than those of AMs, possibly due to a sudden increase in unselective filtering. From the eighth day NAM mortality decreased rapidly and then stabilized, becoming similar to that of AMs through the end of the experiment. Stocking both AMs and NAMs increased the NH4-N concentration in the water, and the mortality rates of both mussel populations were correlated with NH4-N. In contrast, other nutrients and microcystin concentrations were not significantly associated with mussel mortality. These results indicate that although a sudden introduction of non-acclimatized C. leana may partially control phytoplankton biomass fora short period, previous short-term acclimatization is needed to minimize mussel mortality. 相似文献
300.
Arsenic (As) contamination has become a serious environmental problem in many countries. We have performed batch-type leaching
experiments on mine tailing soils collected from three abandoned mine areas in South Korea with the objective of evaluating
the effect of indigenous bacterial activity on As mobilization. The analysis of physicochemical properties and mineralogical
compositions of the samples indicated that the secondary minerals or phases formed as a result of the oxidation or alteration
of primary minerals were associated with the labile and bioleachable fractions of As. Compared to simulated abiotic processes
using sterilization, the indigenous bacteria activated using a carbon source were able to enhance the dissolution of As under
both aerobic and anaerobic conditions. The bacterial dissolution of iron (Fe) and manganese (Mn) was found to occur simultaneously
with the dissolution of As, suggesting that the main bacterial mechanism was via the dissimilatory reduction of Fe(III),
Mn(IV), and As(V). An anaerobic environment was more favorable for the prominent dissolution of As in the tailing soils. These
results indicate that the mobilization of As can be enhanced in the oxygen-depleted part of the tailing dump, particularly
with the infiltration of organic substrates. The difference in the degree of As lixiviation between the three tailing soils
was found to be related to the bioavailability of As as well as the original biomass in the tailing soils. 相似文献