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1.
Methods for induced spawning and artificial incubation of Tilapia nilotica and T. aurea are described. These methods were required for the production, in aquaria, of F1 hybrids between the two species. Spawning families were established in long aquaria from which sexually ripe individuals were selected for stripping by their “on heat” display coloration. Injections of pituitary hormones were not required. The fertilized eggs were incubated in a low speed “shaker”. At correct temperatures Tilapia fry may be produced by this artificial process all year round. 相似文献
2.
Theonella swinhoei is a fairly common inhabitant of reefs throughout the Indian and Pacific Oceans. Metabolomic analyses of samples of T. swinhoei collected in different depths in the Gulf of Aqaba revealed two chemotypes differing in the profiles of the theonellamides they produce, some of which seem to be unknown. Driven by this finding, we examined a sample of T. swinhoei collected more than 40 years ago in the southern part of the Gulf of Aqaba. Large-scale extract of this sample yielded four theonellamides, the known theopalauamide (4), as the major component, and three new metabolites, theonellamide J (1), 5-cis-Apoa-theopalauamide (2), and theonellamide K (3), as the minor components. The planar structure of these complex cyclic glycopeptides was elucidated by combination of 1D and 2D NMR techniques and HRESIMS. The absolute configuration of the amino acids was established by Marfey’s and advanced Marfey’s methods, and the absolute configuration of its galactose unit using “Tanaka’s method” for monosaccharides. The biological activity of the pure compounds was tested for antibacterial activity and for cytotoxicity to HTC-116 cell line. The compounds presented significant cytotoxicity against the HTC-116 cell line, illuminating the importance of the Apoa subunit for the activity. 相似文献
3.
Shmuel Moran 《Pest management science》2001,57(3):248-252
Two methyl anthranilate formulations, ReJex‐iT® TP‐40 and AG‐36, were tested as bird‐repelling agents for animal feed and vegetable sprouts, respectively. Feral pigeons (Columba livia) and house sparrows (Passer domesticus) are important pests of animal husbandry and field crops in Israel. In each 4‐day experiment, four birds were held together in an aviary, and were offered four trays or dishes with animal feed or cauliflower sprouts in four corners of the cage. The trays and dishes were transposed daily in a Latin square sequence. Pigeons consumed significantly more untreated feed than treated feed. When no alternative untreated food was offered, there was no significant repellency. Treatment of animal feed with TP‐40 to give 2.0 ml methyl anthranilate kg?1 or less had no repellent effect on sparrows. Concentrations of 4.0 ml kg?1 or more repelled the sparrows significantly. When no untreated feed was presented, pigeons and sparrows preferred the lowest concentration of methyl anthranilate presented. When AG‐36 was tested on vegetable sprouts, the sparrows tended significantly to avoid the highest concentration used—14.5 ml methyl anthranilate litre?1 spray. The inter‐specific differences between the birds indicate that the efficacy of methyl anthranilate formulations as a repellent has to be specified for every species. This study did not determine (1) the possibility of developing habituation, (2) the behaviour of birds under natural conditions in the field, or (3) the influence of the feeding behaviour of a sympatric bird species on the repellency of methyl anthranilate to other species. © 2001 Society of Chemical Industry 相似文献
4.
Uri Bargai VMD AB DVSc Theodor Nobel DVM† Shmuel Pearl DVM† 《Veterinary radiology & ultrasound》1984,25(5):235-239
Ten beef bulls infected with Besnoitiosis were examined radiographically and pathologically. Eight of these were slaughtered soon after diagnosis; two were left for a six-month observation period. The radiographic findings were focal and branching-tree calcification of the testes. Histopathologic examination proved these calcifications to be necrotic sections of the seminiferous tubules. Radiography of the testes as a means of evaluating the fertility status of the infected bull is recommended. 相似文献
5.
6.
Eight new and four known peptaibols were isolated from a strain of the fungus, Trichoderma atroviride (NF16), which was cultured from an Axinellid sponge collected from the East Mediterranean coast of Israel. The structures of the pure compounds were determined using HRMS, MS/MS and one- and two-dimensional NMR measurements. The isolated compounds belong to the trichorzianines, a family of 19-residue linear hydrophobic peptides containing a high proportion of α-aminoisobutyric acid (Aib), an acetylated N-terminus and a C-terminal amino alcohol. These new peptaibols exhibited antimicrobial activity against environmental bacteria isolated from the Mediterranean coast of Israel. 相似文献
7.
Despite the steadily increasing area under protected agriculture there is a current lack of knowledge about the effects of
the 30% black shading screen on microclimate and crop water requirements. Meteorological and lysimeter measurements inside
a screenhouse planted with sweet pepper were compared to external reference data. Irrigation water use efficiency (IWUE) was
calculated from yield records Y and water meter readings I
applied. Shading reduced mean global radiation R
G
by more than 40%, and the screen transmissivity τ
screen was shown to vary with solar elevation angle β. Wind speed inside the screenhouse u
in was reduced by more than 50%. Crop water requirements ET
c
were 38% lower than estimates for an open field crop, suggesting a significant water saving potential when using screenhouses.
However, the screen did not significantly modify maximum temperature T
max and daily vapor pressure deficit. The FAO-Penman–Monteith approach based on meteorological measurements in the screenhouse
accurately predicted daily crop evapotranspiration, and was in close agreement with lysimeter measurements. IWUE was relatively
high (10.7 kg m−3 in 2004 and 13.5 kg m−3 in 2005), but additional research is required to quantify the effect of shading on yield as well as to determine the water
saving potential of other commonly used screens.
Contribution no. 603/06 from the Agricultural Research Organization
An erratum to this article can be found at 相似文献
8.
Rock hyraxes (Procavia capensis) were individually caged and were given two second-generation anticoagulants, difenacoum and difethialone, in fresh sliced apple bait. Mortality caused by 0.1-0.2 g kg?1 difenacoum bait was rather low: 0/6, 1/4 and 2/4 only. As a relatively high concentration in the bait was required, the use of difenacoum in the field is not possible because of environmental considerations. Mortality caused by 0.05 g kg?1 difethialone bait was 5/6, and by 0.065 g kg?1 6/6. The potential of using difethialone in the field is uncertain because of the prolonged treatment needed. 相似文献
9.
The checklist of vertebrate pest species responsible for economic damage to agriculture production in Israel, which was first
published in 1993, has been updated for 1993–2001. During this period new crop types have been damaged by these pests, and
they have been added to the checklist. Four new bird pest species were also added:Carduelis chloris, Anas platyrhinchos, Larus ridibundus andPelecanus onocrotalus. Thus the number of economically significant vertebrate species is now 65 (27 mammalian, 36 avian and two reptilian species).
Cases of depredation in forestry and pasture, which were not included in the former list, were also added. The significance
of the compiled data in assisting with farm management decision is also discussed.
http://www.phytoparasitica.org posting Jan. 29, 2003. 相似文献
10.
A novel approach to denitrification processes in a zero-discharge recirculating system for small-scale urban aquaculture 总被引:3,自引:0,他引:3
Alon Singer Shmuel Parnes Amit Gross Amir Sagi Asher Brenner 《Aquacultural Engineering》2008,39(2-3):72-77
This paper presents an innovative process to solve the nitrate build-up problem in recirculating aquaculture systems (RAS). The novel aspects of the process lie in a denitrification bioreactor system that uses solid cotton wool as the primary carbon source and a unique degassing chamber. In the latter, the water is physically stripped of dissolved gaseous O2 (by means of a Venturi vacuum tube), and the subsequent denitrification becomes more efficient due to elimination of the problems of oxygen inhibition of denitrification and aerobic consumption of cotton wool. The cotton wool medium also serves as a physical barrier that traps organic particles, which, in turn, act as an additional carbon source for denitrification. Operation in the proposed system gives an extremely low C/N ratio of 0.82 g of cotton wool/g of nitrate N, which contributes to a significant reduction of biofilter volume. The additional advantage of using solid cotton wool as the carbon source is that it does not release organic residuals into the liquid to be recycled. Operation of the system over a long period consistently produced effluents with low nitrate levels (below 10 mg N/l), and there was only a very small need to replace system water. The overall treatment scheme, also incorporating an aerobic nitrification biofilter and a granular filtration device, produced water of excellent quality, i.e., with near-zero levels of nitrite and ammonia, a sufficiently high pH for aquaculture, and low turbidity. The proposed system thus provides a solution for sustainable small-scale, urban aquaculture operation with a very high recovery of water (over 99%) and minimal waste disposal. 相似文献