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1.
Brans of 23 traditional and 12 improved (both red and white) rice varieties in Sri Lanka were screened for anti-amylase and anti-glycation activities in vitro. Varieties which showed the highest inhibitory activities at screening were further investigated for anti-glucosidase and glycation reversing as anti-diabetic properties. The same varieties were studied for selected antioxidant properties. Significantly high anti-amylase and anti-glycation activities were observed for bran extracts of red varieties compared to white varieties at screening. Traditional red rice varieties, Masuran, Sudu Heeneti, Dik Wee and Goda Heeneti, exhibited significant and dose dependent anti-amylase, anti-glycation and glycation reversing activities. These varieties also showed marked antioxidant properties. It is concluded that brans of Sri Lankan traditional red rice varieties Masuran, Sudu Heeneti, Dik Wee and Goda Heeneti may be potential food supplements for diabetes.  相似文献   
2.
为了定性地研究微分方程系统,通常要讨论中心-焦点问题。本文讨论了一类Lienard系统,通过证明定理,指出连续奇,偶次这类系统在原点具有不同的拓扑结构(即相连奇,偶次系统不能同时为中心),以便于进一步求得该系统的焦点量上界问题。  相似文献   
3.
实验教学是高等教育创新人才培养体系的重要组成部分,要加强学生的创新意识和实践能力的培养,必须依靠高水平的实践教学过程的训练。笔者在简要分析植物生产类专业人才培养模式现状的基础上,结合江西农业大学植物生产国家级实验示范中心建设实践,介绍了通过转变实验教学理念,全方位深化实验教学改革,创新人才培养模式,以此提高农业创新人才培养质量。  相似文献   
4.
对塞罕坝机械林场林木良种基地建设的基本条件、必要性及优势进行了分析。并对林木良种基地建设的管理提出了合理化建议。  相似文献   
5.
The crossing of host species barriers, through the spreading populations of introduced pet animals that become established in the wild, sets the stage for zoonotic pathogen (re)emergence. A literature review on pathogens that are hosted by the ring-necked parakeet (Psittacula krameri), a worldwide introduced pet, highlighted local infections of captive birds by chlamydial agents with high sanitary risk for human health in its introduced range. We searched for these pathogens through cloacal swabs collected from 85 individuals in an invasive population established in the suburban areas of Paris (Ile-de-France) from 5 localities during the winter seasons between 2011 and 2014. Based on quantitative PCR analysis, Chlamydiaceae shedding was detected at too low levels for species identification in 5 birds, but 1 parakeet (found dead) was positive for Chlamydiaceae typed as Chlamydia avium. The only known hosts recorded for C. avium in Europe are feral pigeons (Columba livia) and captive psittacines. This result raises the question of the sanitary risks associated with new pathogen transmission from exotic pets released in the wild, which could locally affect birds and potentially people who feed birds.  相似文献   
6.
为了了解间伐对华北落叶松人工林凋落物和土壤理化性质的影响,利用试验测定和定量统计的方法,分析比较了河北省塞罕坝机械林场间伐和未间伐华北落叶松人工林凋落物层和土壤层(0~10cm、10~20cm)的理化性质,结果显示:与未间伐林分相比,50%强度间伐6a后林分内凋落物层生物量、质量含水量、有机质含量和全氮含量分别提高了17.25%、6.05%、9.08%、31.94%;土壤层的质量含水量、土壤容重和有机质含量有所上升(0~10cm土壤层分别增加4.84%、11.11%、15.67%;10~20cm土壤层分别增加10.25%、12.50%、28.97%),而全氮含量呈下降趋势(0~10cm土壤层减少20.83%;10~20cm土壤层减少16.67%);土壤pH值亦有所下降。研究进一步证实,通过间伐能够增加地表凋落物生物量,改变有机质分解速率,从而在一定程度上影响土壤的理化特性。  相似文献   
7.
Microsatellite markers were used to analyse the biodiversity of 57 accessions of different subspecies and varieties of wild Aegilops tauschii (2n = 2x = 14; D genome) collected across the major areas where it grows in Iran. Levels of diversity were high, with numbers of alleles averaging 7.3 (ranging up to 12) and polymorphism information contents averaging 0.6591. One accession was notably more similar to two of the D genome in hexaploid wheats (Triticum aestivum) used as outgroups. Within the Ae. tauschii accessions, no markers were characteristic for taxa or geographical origin, suggesting high gene flow between the subspecies and varieties, although some groupings, which could be related to geographical origin, were evident. This survey demonstrates the high diversity present in wild goatgrass in Iran, and indicates that there is value in sampling for useful genes for wheat breeding.  相似文献   
8.
Conversion of tropical forests to oil palm plantations in Malaysia and Indonesia has resulted in large-scale environmental degradation, loss of biodiversity and significant carbon emissions. For both countries to participate in the United Nation’s REDD (Reduced Emission from Deforestation and Degradation) mechanism, assessment of forest carbon stocks, including the estimated loss in carbon from conversion to plantation, is needed. In this study, we use a combination of field and remote sensing data to quantify both the magnitude and the geographical distribution of carbon stock in forests and timber plantations, in Sabah, Malaysia, which has been the site of significant expansion of oil palm cultivation over the last two decades. Forest structure data from 129 ha of research and inventory plots were used at different spatial scales to discriminate forest biomass across degradation levels. Field data was integrated with ALOS PALSAR (Advanced Land-Observing Satellite Phased Array L-band Synthetic Aperture Radar) imagery to both discriminate oil palm plantation from forest stands, with an accuracy of 97.0% (κ = 0.64) and predict AGB using regression analysis of HV-polarized PALSAR data (R2 = 0.63, p < .001). Direct estimation of AGB from simple regression models was sensitive to both environmental conditions and forest structure. Precipitation effect on the backscatter data changed the HV prediction of AGB significantly (R2 = 0.21, p < .001), and scattering from large leaves of mature palm trees significantly impeded the use of a single HV-based model for predicting AGB in palm oil plantations. Multi-temporal SAR data and algorithms based on forest types are suggested to improve the ability of a sensor similar to ALOS PALSAR for accurately mapping and monitoring forest biomass, now that the ALOS PALSAR sensor is no longer operational.  相似文献   
9.
氮肥用量对苏中冬小麦地上部主要矿质元素含量的影响   总被引:1,自引:0,他引:1  
为了明确施氮量对苏中地区冬小麦主要矿质元素含量的影响,以扬麦11和扬麦13为材料,在江苏丹阳设置3个氮素水平(0、150、300kg.hm-2),研究不同施氮量对冬小麦籽粒、茎鞘和叶片中Fe、Zn、Mn、Cu、Ca、Mg和P等矿质元素含量的影响。结果表明,增施氮肥能显著提高冬小麦籽粒、茎鞘、叶片、面粉和麸皮中的Fe、Zn、Mn、Cu和Ca含量,但P含量明显下降。与对照(N0)相比,施氮量达300kg.hm-2时,扬麦11籽粒中的Fe、Zn、Mn、Cu和Ca含量分别增加了11.74%、32.20%、31.78%、66.87%和53.75%,P含量降低23.06%,茎鞘中Zn、Cu和Ca含量增加106.34%、136.97%和51.15%,P含量降低46.46%;扬麦13籽粒中Zn、Cu和Ca含量分别比对照(N0)增加33.03%、59.67%和56.63%,Mg和P含量分别降低14.10%和25.41%,叶片中Mn、Cu、Ca和Mg分别增加174.54%、27.15%、41.66%和29.95%。随着氮肥用量增加,籽粒中Mg含量呈下降趋势,但茎鞘和叶片中Mg含量呈递增趋势。籽粒、茎鞘和叶片中不同矿质元素含量对氮肥的响应存在品种间差异。在本试验条件下,适量施氮可以提高冬小麦籽粒中微量元素的含量。但是,氮肥用量过高可能降低籽粒中P和Mg的含量,不利于籽粒矿质营养品质的提高。  相似文献   
10.
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