森林资源时态GIS数据存储与时空分析方法研究

在分析时态数据库的研究与应用现状基础上,针对森林资源数据特点,在对象—关系Oracle数据库上,扩展基本数据类型和函数集,实现森林资源时空数据的有效储存,对森林资源数据的现状及变化等基本信息进行空间拓扑、时态拓扑和时空拓扑操作,提供完善的时序分析功能,高效地回答与时间相关的各类问题,准确地描述森林资源信息,完整地反映森林资源演变过程,为森林资源数据管理提供服务,对森林资源数据库的建设提供新的思路和方法。     

The relationship of calfhood morbidity with survival after calving in 25 New York Holstein herds

The association of owner-diagnosed calfhood diseases with the length of herd life after calving was evaluated using data collected prospectively over a ten-year period in 25 New York Holstein dairy herds. Herds selected for the study were milking between 35 and 200 Holstein cows, used dairy herd improvement records, bred cows by artificial insemination unless they needed three or more services, and had regularly-scheduled herd health visits by clinicians from the Cornell University College of Veterinary Medicine. Owners recorded occurrences of dullness, respiratory disease, and scours from birth through 90 days of age for all heifer calves that lived at least 24 h and were to be kept as replacements. Milking herd life was measured as the difference between the age at first calving and the age at death or sale. Data on cows sold when the herd went out of business or still in the herd at the end of the study were censored observations. Cox's proportional hazards model was used for statistical analysis of the data. Controlling for age at first calving, study month of birth, and sire predicted difference for milk, there was no statistically significant association of calfhood morbidity with length of herd life. The estimated hazard rate ratios for leaving the milking herd and 95% confidence intervals for dullness, respiratory disease, and scours within 90 days of birth were 1.3 (0.9, 1.9), 0.9 (0.6, 1.3), and 1.0 (0.8, 1.3), respectively. Dullness was the only disease category with an estimated hazard rate ratio greater than 1, and although it was not statistically significant, may warrant evaluation in future studies of long term effects of calfhood morbidity.     

Development of a method for the identification, using the polymerase chain reaction, of Aspergillus fumigatus isolated from ostriches

Objective To develop a method for identifying DNA of Aspergillus fumigatus from ostriches, using the polymerase chain reaction (PCR). A fumigatus is the principal causative agent of avian aspergillosis.
Design A biochemical trial.
Sample population Twelve Aspergillus fumigatus isolates and three other Aspergillus species.
Procedure PCR primers that were based on the sequence of the alkaline protease gene from human isolates of A fumigatus were used.
Results We successfully tested the method on ostrich isolates from five states and showed that the test is specific for A fumigatus.
Conclusions In most cases the DNA sequence of A fumigatus isolates from ostriches is similar to that of human isolates. DNA sequences vary significantly among A fumigatus isolates, including those from affected ostriches in the same flock. The genetic variation may be used to trace aspergillus infections in ostrich flocks and determine if the disease is transmitted by contact with infected birds.     

Detection of APAF1 mutation in Holstein cows and mummified foetuses in Japanese dairy herds

Some of the highest genetic merit sires have been shown to harbour recessive mutations affecting fertility, which may spread rapidly in the population through AI. These disorders may result in abortion and decline in pregnancy per insemination in cows. This study was carried out on 240 Holstein‐Friesian cows and 15 mummified foetuses. Blood and tissue samples were collected from the cows and mummified foetuses, respectively, for DNA extraction. Allele‐specific PCR was designed for the detection of the cows and foetuses carrying the nonsense mutation (C/T) in apoptosis peptide activating factor 1 gene (APAF1). The mutant allele frequency of the APAF1 in carrier cows and mummified foetuses was calculated. Milk samples were taken from the carrier and non‐carrier cows for progesterone assay. The allele‐specific PCR reaction efficiently distinguished the C/T mutation in APAF1. Of 240 cows, seven cows (2.9%) were diagnosed to carry one copy of the mutant allele of APAF1. However, the carrier frequency was 33.3% in mummified foetuses (five of 15). The mutant allele frequency was 0.02 and 0.17 in the cows and mummified foetuses, respectively. Concentrations of progesterone did not differ between cows with APAF1 mutation and non‐carrier cows during 45 days post‐insemination. This study provided allele‐specific PCR for the detection of APAF1 mutation in cows. Moreover, it reports the carrier and mutant allele frequencies of APAF1 in dairy cows and mummified foetuses in Japan.     

Detection of the Matrix Metalloproteinases MMP‐2 and MMP‐9 and Tissue Inhibitors of Metalloproteinases TIMP‐1 and TIMP‐2 in Llama (Lama glama) Oviduct

Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are involved in several reproductive events like oocyte–spermatozoa interaction and semen liquefaction. In order to study their role in the llama oviductal reproductive process, MMP activity in oviductal fluid (OF) was assayed. Considering that llama genome sequences are partially known, a strategy to procure cDNA sequences of MMP‐2, MMP‐9, TIMP‐1 and TIMP‐2 was designed. Afterwards, their expression patterns in the different llama oviductal segments were assayed. Gelatine zymograms detected 62 and 94 kDa protease activities that matched MMP‐2 and pro‐MMP‐9, respectively. Expression pattern analysis showed that MMP and TIMP mRNAs were present in ampulla, isthmus, utero‐tubal junction (UTJ) and papilla. Altogether, these findings support the argument that MMPs/TIMPs are produced in the oviduct and secreted into the oviductal lumen. Our results encourage further studies to elucidate the role of these proteins in reproductive oviductal events.     

乌冈栎种群天然更新研究

种群更新对维持种群的稳定和发展具有极其重要的意义。通过野外实地调查,对不同地区乌冈栎种群的更新情况进行了分析,结果如下:1)大多数地区乌冈栎种群的幼苗结构呈倒金字塔型,说明乌冈栎种群的更新存在一定的困难;但在乌冈栎顶级群落中,由于仍存在一定数量的幼树,短期内的更新仍能继续进行;2)从乌冈栎幼苗空间分布格局来看,林窗或林缘处呈聚集分布,而林冠下呈均匀分布,这与乌冈栎幼苗生长的需光性有极大的关系;3)乌冈栎的萌发实验表明,1～2个月的沙藏处理有利于提高萌发率,而萌发过程中鼠害和虫蛀是限制出苗率的主要原因之一;4)乌冈栎种子的传播除靠重力外,啮齿类动物对它的影响最大,他们之间存在一定的权衡关系。为了提高乌冈栎种群的天然更新率,适当干扰地开辟林窗是较佳的途径。     

Biomass recalcitrance: engineering plants and enzymes for biofuels production

Lignocellulosic biomass has long been recognized as a potential sustainable source of mixed sugars for fermentation to biofuels and other biomaterials. Several technologies have been developed during the past 80 years that allow this conversion process to occur, and the clear objective now is to make this process cost-competitive in today's markets. Here, we consider the natural resistance of plant cell walls to microbial and enzymatic deconstruction, collectively known as "biomass recalcitrance." It is this property of plants that is largely responsible for the high cost of lignocellulose conversion. To achieve sustainable energy production, it will be necessary to overcome the chemical and structural properties that have evolved in biomass to prevent its disassembly.     

Early maritime economy and El Nino events at quebrada tacahuay, peru

The archaeological site of Quebrada Tacahuay, Peru, dates to 12,700 to 12,500 calibrated years before the present (10,770 to 10,530 carbon-14 years before the present). It contains some of the oldest evidence of maritime-based economic activity in the New World. Recovered materials include a hearth, lithic cutting tools and flakes, and abundant processed marine fauna, primarily seabirds and fish. Sediments below and above the occupation layer were probably generated by El Nino events, indicating that El Nino was active during the Pleistocene as well as during the early and middle Holocene.