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1.
Journal of Soils and Sediments - Bedload transport discharge is important in river engineering and morphodynamics. The Meyer-Peter and Müller (MPM) equation for determining bedload transport...  相似文献   
2.
The COVID-19 pandemic and its continuing emerging variants emphasize the need to discover appropriate treatment, where vaccines alone have failed to show complete protection against the new variants of the virus. Therefore, treatment of the infected cases is critical. This paper discusses the bio-guided isolation of three indole diketopiperazine alkaloids, neoechinulin A (1), echinulin (2), and eurocristatine (3), from the Red Sea-derived Aspergillus fumigatus MR2012. Neoechinulin A (1) exhibited a potent inhibitory effect against SARS-CoV-2 Mpro with IC50 value of 0.47 μM, which is comparable to the reference standard GC376. Despite the structural similarity between the three compounds, only 1 showed a promising effect. The mechanism of inhibition is discussed in light of a series of extensive molecular docking, classical and steered molecular dynamics simulation experiments. This paper sheds light on indole diketopiperazine alkaloids as a potential structural motif against SARS-CoV-2 Mpro. Additionally, it highlights the potential of different molecular docking and molecular dynamics simulation approaches in the discrimination between active and inactive structurally related Mpro inhibitors.  相似文献   
3.
A crossbreeding experiment was carried out to determine the sire breed effects on fattening performance of fat-tailed lambs. Rams from four Iranian fat-tailed sheep breeds, namely Kurdi (K), Afshari (A), Chaal (C) and Sanjabi (S) were mated to Kurdi ewes producing 454 progeny of four genotype groups (KK, AK, CK and SK). A total of 80 lambs comprising ten female and ten male lambs from each genotype group were used in a fattening experiment during a period of 88 days. Genotype of the lamb had significant effect on average dry matter intake (ADMI) (P < 0.05). SK lambs had the lowest ADMI. Average daily gain (ADG) and food conversion ratio (FCR) were not influenced by genotype of the lamb. Sex of the lamb had significant effect on both ADG and FCR (P < 0.01). Slaughter weight (SLW), hot carcass weight (HCW), cold carcass weight (CCW) and daily carcass gain (DCG) were not affected by lamb's genotype. However, genotype had significant effect on dressing percentage, carcass loss percentage (P < 0.01), carcass length (CL), leg circumference (LC), carcass compactness (CC) (P < 0.01) and carcass density (CD) (P < 0.05). Carcass width (CW) and leg length (LL) were not affected by lamb's genotype. Sex of the lamb had significant effects on CL, CW, LC, CC, CD (P < 0.01) and LL (P < 0.05). The results indicated the existence of sire breed difference for daily dry matter intake and carcass conformation in the fat-tailed sheep.  相似文献   
4.
Septoria tritici blotch (STB), caused by Mycosphaerella graminicola has recently become one of the devastating diseases in Iran causing significant yield losses on most commercial bread and durum wheat cultivars. Iran is located in the Fertile Crescent, a region where wheat was historically domesticated; and, thus, landraces derived from this region are of considerable global interest for identification of new sources of resistance to various stresses. Here, we report on the resistance responses of 45 tetraploid wheat landraces collected from different provinces of Iran to eight M. graminicola isolates. In total 138 isolate-specific resistances were found among all interactions (n = 360). The highest number of specific resistances (30 out of 32 interactions) was found in wheat landraces collected from West Azarbaijan. In contrast, all landraces from Kordestan were highly susceptible to M. graminicola isolates and only one isolate-specific resistance was identified among 106 isolate-wheat interactions. Kermanshah landraces showed the highest resistance variation against different isolates. About 57 isolate-specific resistances were identified among 104 interactions. Ilam landraces were highly resistant to STB as 28 specific resistances were observed among 32 interactions. Markazi (n = 2) and Sistan-Baluchestan (n = 1) were susceptible to all isolates tested. Landraces from Lorestan were generally susceptible to isolates tested as 26 susceptible responses were observed out of 32 interactions. Our results indicate that landraces collected from the Fertile Crescent region may possess diverse effective resistance genes or valuable broad spectrum resistance genes, and that their identification is of interest and can be exploited in breeding programs.  相似文献   
5.
Allelopathy is a procedure in which secondary metabolites are produced by plants. Some plants may beneficially or antagonistically affect other plants through allelochemical compounds which may be released directly or indirectly from live or dead parts and cause allelopathic and phytotoxic effects. The aim of the present study was to investigate the allelopathic possibility of ajowan (Carum copticum) extracts in different concentrations on morphological indices (germination and growth) of wheat (Triticum sativum), barley (Hurdeum vulgare), corn (Zea maize S.C 704), and safflower (Carthamus tinctorius L.) seedlings as proceeding crops and to develop a comprehensive formula for measuring the negative and positive effects of allelochemicals on growth indices such as shoot and root length, as well as the germination percentage on donor plants. It was demonstrated that increasing concentrations of ajowan extracts significantly decreased the Allelopathic Index, percent of germination, and other growth related indices of all seedlings. Based on the proposed Allelopathic Index of experimental plants, it was revealed that ajowan has posed a higher risk to corn and barley especially at the early stages of the growing cycle, while safflower and wheat indicated more tolerance to growth inhibition effects of ajowan in rotational sequence.  相似文献   
6.
Journal of Crop Science and Biotechnology - Salinity is one of the most brutal abiotic stressors, commencing a great stumbling block in the way of attaining food security in Bangladesh. Cultivation...  相似文献   
7.
Polypropylene fabrics were coated with copper particles using electroless plating, screen printing and wire arc spray coating techniques. Surface morphology of the fabrics was studied using optical and scanning electron microscopes (SEM). Furthermore, tensile strength, electrical conductivity, thermal conductivity, air permeability, water contact angle and fog collection efficiency of the coated fabrics were measured and the obtained results were analyzed. SEM micrographs showed that a very thin and uniform layer of copper deposited on the surface of the electroless plated polypropylene fibers. In the printed or spray coated fabrics the copper particles filled the spaces between yarns and fibers. The polypropylene electroless copper plated fabrics showed higher tensile strength, electrical conductivity, air permeability and thermal conductivity when compared with the fabrics coated with copper screen printed and copper spray coated fabrics. Finally, the obtained results showed that copper electroless plating could increase the fog collection efficiency of polypropylene fabrics considerably. As a conclusion, the surface modified copper electroless polypropylene fabrics are good candidates for fog collection in appropriate regions which need further investigations.  相似文献   
8.
The effects of feeding time and frequency on the growth, feed utilization and survival of Clarias gariepinus (Burchell 1822; family Clariidae) fingerlings were evaluated in a 25-day study. Groups of African catfish with an initial individual weight of 0.98 ± 0.02 g were offered feeds continuously for 24 h, or during the day or night at different time intervals, with varying meal size. The growth rate was significantly affected by meal times. Widely practised day time feeding with three equal size meals a day gave the lowest growth and highest food wastage. The growth rates of fish fed continuously or during night time following their feed demand were significantly higher with lowest food conversion ratios and food wastage.  相似文献   
9.
The effects of saline-dissolved or Freund's incomplete adjuvant (FIA)-emulsified GnRHa treatment on the induction of ovulation in rainbow trout, Oncorhynchus mykiss, were examined. The FIA-emulsified GnRHa was first diluted in 0.25 ml physiological saline and then mixed with an equal volume of FIA. Fish were selected in the beginning of the spawning season and were allocated into four groups and were treated intraperitoneally with (a) 0.5 ml of emulsified GnRHa (GnRHa–FIA), (b) 0.5 ml saline-dissolved GnRHa in a single injection (GnRHa-1), (c) 0.5 ml saline-dissolved GnRHa in two injections spaced 1 d apart (GnRHa-2) and (d) 0.5 ml of saline (Control). The GnRHa dose in all hormone treatments was 25 µg kg− 1. All fish in the FIA–GnRHa and GnRHa-2 groups ovulated within 10 and 11 d after treatment, respectively. In contrast, only 75% in the Control fish and 60% of the fish in the GnRHa-1 group ovulated within 36 d after treatment. None of the treatments caused any pre- or post-spawning mortality in the broodstock. Fertilization, eyeing and hatching percentages of the produced progeny were normal in all the treatment groups and did not differ significantly among them. In conclusion, FIA-emulsified GnRHa can be effective in advancing the onset of and synchronizing the ovulation of rainbow trout within a two-week period, thus shortening the egg collection period, without affecting broodstock survival and egg quality.  相似文献   
10.
The effect of oil pollution on growth and metabolic activitiesof the fresh water algae Chlorella homosphaera and C.vulgaris was studied. The study was conducted on two locationsin the river Nile, one is oil polluted and the other is notpolluted. The assemblage of the different algal groups wasmonitored in both locations. Chlorophyta was more dominant thanCyanophyta and Bacillariophyta in both locations during allseasons except in winter when Bacillariophyta is the mostdominant group. The presence of crude oil or its refineryproducts (solar and lubricating) in the culture media of algaemarkedly influenced their growth, proteins and nucleic acidcontents. The toxicity of oil was a concentration dependent. Thelow concentrations stimulated growth, protein content andnucleic acids, whereas high concentrations had an inhibitoryeffect. Although DNA and RNA responded similarly to crude oil inthe two tested organisms, DNA showed more sensitivity than RNAto solar oil. Lubricating oil had a little phytotoxic effect onnucleic acids. Different species of algae response differentiallyto oil pollution; Chlorella vulgaris can be referred to asoil-sensitive, while Chlorella homosphaera can toleraterelatively higher concentrations of oil.  相似文献   
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