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排序方式: 共有148条查询结果,搜索用时 15 毫秒
1.
Paddy and Water Environment - Water adaptation strategies are necessary for decreasing climate change impacts on local societies. This study models a community water supply system as a distributed... 相似文献
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3.
Aedes albopictus and Culex quinquefasciatus were fed canine blood with different microfilarial density of Dirofilaria immitis ranging from 2500 to 25,000 mff/ml. Larval development in these two mosquito species did not differ significantly. Although C. quinquefasciatus ingested more microfilariae, the number of larvae which developed in A. albopictus was invariably greater than in C. quinquefasciatus. Mortality of the engorged A. albopictus was significantly greater than that of C. quinquefasciatus, and higher microfilarial density raised the mortality in both species. The vector efficiency index of A. albopictus was greater than C. quinquefasciatus at all microfilarial densities, but its survival time was much reduced. Thus, dogs with low microfilarial density are implicated as the main source for the transmission of D. immitis from dogs to mosquitoes. 相似文献
4.
This article analyzes the relationship between forest resources, refugees, and the host population. The findings of the research
suggest that the host population are heavily dependent on the local forest for their daily needs such as fuelwood, timber,
grazing area, fodder for domestic animals, foods, and medicine in addition to cultural and esthetic needs. The forest has
also been relied upon for agricultural needs such as manufacture of agricultural tools, maintenance of irrigation water systems,
erosion control, and fertilizer needs. The forest was under a sustained demand as any other Terai forest of Nepal. After the
arrival of refugees in 1992, the demand for forest resources increased substantially. Initially, the construction of the refugee
camps decreased the total forest area and also required some felling of trees. More significantly, the refugees themselves
became active users of the forest resource, which generated extra pressure on the forest and created scarcity of forest resources.
Before the arrival of the refugees, forest management and monitoring of illegal use of the forest resources were carried out
by the government through its local forester office. The local residents were active users of the forest resources, but were
passive in managing and maintaining the forest resource. However, competition from the refugees instilled a desire in the
local population to safeguard and protect the dwindling resource against the external threat by creating the Humse Dumse Community
Forest. 相似文献
5.
Dormancy induction in container-grown Abies seedlings: Effects of environmental cues and seedling age 总被引:1,自引:0,他引:1
Twelve-week-old container-grown seedlings of noble fir (Abies procera Rehd.) and Shasta red fir (A. magnifica A. Murr. var. shastensis Lemm.), both high-elevation species, were grown under controlled environments in a study of induction of terminal-bud dormancy. Eight treatment combinations of long (15 h) or short (11 h) photoperiods, warm (25°/20°C) or cool (18°/12°C) thermoperiods, and dry (–1.2 MPa) or wet (–0.6 MPa) moisture regimes were imposed upon seedlings for 12 weeks. Treatment factors significantly affecting the induction of dormancy in terminal buds of seedlings were identified over time. The results suggest that seedlings responded dynamically to dormancy cues. The warm/dry and cool/wet combinations induced dormancy in the first 2 weeks in noble fir and in the first week in Shasta red fir. Short-day/warm and long-day/cool combinations enhanced dormancy induction in weeks 3 to 4 in noble fir and in weeks 1 to 7 in Shasta red fir. Short days and cool thermoperiods independently hastened dormancy induction in noble fir in weeks 5 through 12. 相似文献
6.
Sujan KC Yamamoto Hiroyuki Matsuo Miyuki Yoshida Masato Naito Kazuhiro Shirai Tatsuya 《Wood Science and Technology》2015,49(6):1157-1169
Wood Science and Technology - Tension wood, when kiln-dried, is likely to deform hugely, which is probably caused by a gelatinous layer of the gelatinous fiber. To elucidate the mechanism behind... 相似文献
7.
Tanger S. M. Blazier M. A. Holley A. G. McConnell T. E. Vanderschaaf C. Clason T. R. KC Dipesh 《New Forests》2021,52(2):217-235
New Forests - Competition suppression within loblolly pine plantations (Pinus taeda L.) is typically carried out within the first 2 years of a plantation, but competition control for longer... 相似文献
8.
KC Silva‐Santos LS Siloto GMG Santos F Morotti TN Marcantonio MM Seneda 《Reproduction in domestic animals》2014,49(1):48-51
The objective was to compare populations of antral and pre‐antral ovarian follicles in Bos indicus and Bos indicus‐taurus cows with high and low antral follicle counts. Nelore (Bos indicus, n = 20) and Nelore X Angus (1/2 Bos indicus‐taurus, n = 20) cows were subjected to follicular aspiration without regard to the stage of their oestrous cycle (day of aspiration = D0) to remove all follicles ≥3 mm and induce growth of a new follicular wave. Ovaries were examined by ultrasonography on D4, D19, D34, D49 and D64, and antral follicles ≥3 mm were counted. Thereafter, cows were assigned to one of two groups: high or low antral follicular count (AFC, ≥30 and ≤15 antral follicles, respectively). After D64, ovaries were collected after slaughter and processed for histological evaluation. There was high repeatability in the numbers of antral follicles for all groups (range 0.77–0.96). The mean (±SD) numbers of antral follicles were 35 ± 9 (Bos indicus) and 38 ± 6 (Bos indicus‐taurus) for the high AFC group and 10 ± 3 (Bos indicus) and 12 ± 2 (Bos indicus‐taurus) follicles for the low AFC. The mean number of preantral follicles in the ovaries of Bos indicus‐taurus cows with high AFC (116 226 ± 83 156 follicles) was greater (p < 0.05) than that of Bos indicus cows (63 032 ± 58 705 follicles) with high AFC. However, there was no significant correlation between numbers of antral and preantral follicles. 相似文献
9.
KC Silva‐Santos CR Ferreira GMG Santos MN Eberlin LS Siloto CO Rosa TN Marcantonio MM Seneda 《Reproduction in domestic animals》2014,49(5):711-718
The aim of the present study was to compare the lipid profile in oocytes of indicus and 1/2 indicus × taurus cows with high and low antral follicle count (AFC)/oocyte yields. After an OPU procedure (D0), antral follicles ≥3 mm were counted by ultrasonography (D4, 19, 34, 49, 64), and cows were assigned to groups with either high AFC (≥30 follicles; indicus, NH group; 1/2 indicus × taurus, AH group) or low AFC (≤15 antral follicles; indicus, NL group; 1/2 indicus × taurus, AL group). The lipid profiles of the oocytes were determined by MALDI‐MS. For GI, GII and GIII oocytes, the indicus samples tend to cluster separately from the 1/2 indicus × taurus samples. The lipid species [PC (P‐38:5) + H]+ and/or [PC (P‐36:2) + Na]+, [PC (38:2) + H]+, [PC (38:5) + Na]+ and [TAG (60:8) + NH4]+ were more abundant in indicus (NH and NL groups) than 1/2 indicus × taurus. The higher lipid content in the indicus oocytes likely reflects differences in the rate of lipid metabolism and may contribute to oocyte competence and embryo development. 相似文献
10.
Che-Huang Tung 《Journal Of Applied Aquaculture》2013,25(1):14-31
Dual microalgal species biofilms with distinct amino acid characteristics were tested for their effects on abalone (Haliotis iris) initial attachment, metamorphosis, settlement, and survival. Nine microalgal species, isolated from around Auckland, New Zealand, were grown in the laboratory, and used to produce nine dual microalgal species biofilms. Abalone larvae were exposed to the different biofilm treatments and controls (no biofilms) for seven (attachment and metamorphosis) and 14 (settlement and survival) days. The larvae performed significantly better in the dual microalgal biofilms compared to controls, and some biofilms resulted in better attachment, metamorphosis, settlement, and survival than others. For example, the best-performing biofilms almost always contained cyanobacteria (Oscillatoria cf. erythrata, Anacystis cf. aeruginosa, and Schizothrix cf. calcicola), which are attributed with better nutritional values. However, the amino acid profiles did not produce a clear pattern with regard to their effects on the four larval processes. Instead, total amino acid (TAA) content was positively correlated with percentage of attachment and metamorphosis. Greater TAA contents are likely to reflect greater amounts of extra-cellular polymers within the biofilms, which are suggested to improve larval performance. 相似文献