Application of dual-frequency GPS receivers for static surveying under tree canopies

 The objectives of this study are to evaluate the accuracy of dual-frequency GPS receivers in static surveying in forests and to develop a model to estimate the probability of resolving ambiguity by logistic regressions, with independent variables being the observation period length and an index of canopy opening. In this study, a rover receiver was set up at four points in the forest (at a treeless point, under a large canopy gap, under a small canopy gap, and under closed canopies), and static surveys were conducted for 4 h at each point. The observed data were post-processed with the data from the base station, and the baseline data were repeatedly post-processed while changing the length of the observation periods. As a result, positional accuracies were decreased more under tree canopies than at the treeless point, but under tree canopies several integer ambiguities were resolved within 15 min by using a dual-frequency GPS receiver. The result also showed that ambiguity-fixed solutions using a dual-frequency GPS receiver produced the most accurate positional data under tree canopies. Moreover, the probability of resolving ambiguity was estimated by logistic regression with the independent variables being the index of canopy opening and observation period lengths. Received: July 6, 2001 / Accepted: October 25, 2002 Acknowledgments This study was supported in part by a Grant-in-Aid for Scientific Research from the Japan Ministry of Education, Culture, Sports, Science and Technology (No. 12760104). We would like to express our gratitude to Mr. Masayuki Uchiyama and Mr. Yoshito Fujita (Akasaka Tec Inc.) for their experimental support and valuable advice on GPS positioning. Correspondence to:H. Hasegawa     

Herbicide coverage in narrow row soybean as influenced by spray nozzle design and carrier volume

The use of reduced drift nozzles that produce larger droplet sizes that are less prone to drift will likely be required for use of future postemergence herbicide applications in soybean in the USA. Experiments to evaluate the effect of reduced drift spray nozzles on spray solution coverage were conducted in the field in Indiana. Air induction extended range (AIXR) and turbo TeeJet air induction (TTI) nozzles that produce extremely coarse to ultra coarse droplets were compared to extended range (XR) and Turbo TeeJet (TT) nozzle that produced fine to coarse droplets. Each nozzle was evaluated for spray coverage at 94 and 140 l ha⁻¹ spray volumes using water sensitive cards. Precipitation varied between site years and resulted in differences in soybean canopy development and spray solution coverage. Coverage was greater at the top of the canopy than at the bottom of the soybean canopy as expected. An interaction occurred at the top and middle of the canopy in which the AIXR and TTI nozzles had similar coverage between the two spray volumes, whereas the XR and TT nozzles had greater coverage at 140 l ha⁻¹ carrier volume than 94 l ha⁻¹ carrier spray volume. Spray solution coverage at the bottom of the canopy, where target weeds would be, was similar between all nozzle types. Coverage was greater at the bottom of the canopy at 140 l ha⁻¹ spray volume than with the 94 l ha⁻¹ carrier volume. Spray volume has a greater influence on coverage than spray nozzle type and AIXR and TTI nozzles are less prone to coverage differences due to spray volume than the XR and TT nozzles.     

Association of A31P and A74T Polymorphisms in the Myosin Binding Protein C3 Gene and Hypertrophic Cardiomyopathy in Maine Coon and Other Breed Cats

Background: Hypertrophic cardiomyopathy (HCM) is an inherited autosomal dominant trait in cats. The A31P single nucleotide polymorphism (SNP) in the myosin binding protein C 3 gene is thought to be the causative mutation in Maine Coon cats. Additionally, the A74T SNP is offered as a genetic test for HCM. Objectives: To evaluate the genetic association between the above‐mentioned SNPs and phenotypes. Animals: Eighty‐three Maine Coon cats and 68 cats of other breeds. Methods: The study was performed prospectively. Cats were phenotyped as healthy or HCM with echocardiography. Taqman genotyping assays were used for genotyping; results were confirmed by sequencing analysis. Results: A31P was found in 18/83 (22%) Maine Coon cats. Fifteen of 18 Maine Coons (83%) with the A31P mutation were healthy on echocardiographic examination (mean age 65 months). A74T was present in 28/79 (35%) of Maine Coons and in 42/68 (62%) of other cat breeds. Twenty‐two of 28 (79%) of Maine Coons and 21/42 (62%) of other breed cats with the A74T mutation were healthy at a mean age of 72 months and 91 months, respectively. Of 12 Maine Coons with HCM, 9 (75%) were genotype‐negative for A31P and 6 (50%) for A74T. Allele frequencies did not differ significantly (P= .47) between phenotype groups. None of the evaluated genetic tests was able to provide useful predictive information of disease outcome. Conclusions and Clinical Importance: The value of currently available genetic tests is low in the cats of this study. The mutations analyzed appear to have a low penetrance, and even homozygote cats can remain healthy.     

原生质体载体技术在马铃薯育种中的应用

综述了原生质体载体技术在育种中的应用:体细胞杂交、以原生质体为受体细胞的DNA直接导入转化、体细胞无性系变异、胁迫耐受系的选择,同时针对马铃薯的生物学特性、育种现状及其原生质体方面的研究现状,提出利用原生质体载体技术进行马铃薯育种的优势和切实可行性。     

浅谈档案信息化管理——以河北宣化钢铁公司为例

综述档案信息化的内涵、优势和搞好档案工作的重要性及意义。介绍宣化钢铁公司档案信息化管理的具体实施办法及在档案信息化管理工作中遇到的各种问题及解决办法。     

禽巴氏杆菌荚膜多糖-蛋白载体抗原的研究

用EDC法和CNBr法分别交联禽巴氏杆菌荚膜多糖(CPS)与破伤风类毒素(TT),经Sephadex-G150柱层析和薄层层析鉴定表明;两种方法均获得一种大分子的CPS-TT结合物,该结合物免疫鸡的血清经二巯基乙醇(2-ME)处理后用间接血凝试验(IHA)检测出较高滴度的IgG抗体和一定量的IgM抗体,抗体消长情况监测结果;IgG抗体的峰值(4.88)在免疫后第21天,其后缓慢下降,持续至第24周左右。IgM抗体的峰值(4.26)在第14天,其后陡降,至第8周降至阴性血清水平,与对照组差异极显著(P<0.01)。第8周和第24周时测出较强的二次反应和回忆反应。重复试验测出的IgG、IgM抗体滴度与本试验结果相近,第4周时攻毒保护率分别为100％和75％,且IgG抗体滴度与攻毒保护率的相关性较好,1:16以上可获得全保护。试验结果表明交联方法稳定,重复性较好,制备的CPS-TT载体抗原实现了CPS由Ti抗原向Td抗原的转换。为研究一种新型的禽霍乱载体菌苗提供了理论依据和实验手段。     

Simultaneous Estimations of Forest Parameters using Aerial Photograph Interpreted Data and the k Nearest Neighbour Method

Information about the state of the forest is of vital importance in forest management planning. To enable high-precision modelling, many forest planning systems demand input data at the single-tree level. The conventional strategy for collecting such data is a plot-wise field inventory. This is expensive and, thus, cost-efficient alternatives are of interest. During recent years, the focus has been on remote sensing techniques. The k nearest neighbour (kNN) estimation method is a way to assign plot-wise data to all stands in a forest area, using remotely sensed data in connection with a sparse sample of field reference plots. Plot-wise aerial photograph interpretations combined with information from a stand register were used in this study. Nearness to a reference plot was decided upon using a regression transform distance. Standing stem volume was estimated with a relative root mean square error (RMSE) equal to 20% at the stand level, while age could be estimated with a RMSE equal to 15%. A cost-efficient data-capturing strategy could be to assign plot data with the presented kNN method to some types of forest, while using traditional field inventories in other, more valuable, stands.     

Cosegregation of a factor VIII microsatellite marker with mild hemophilia A in Golden Retriever dogs

Mild hemophilia A (factor VIII deficiency) was diagnosed in Golden Retrievers and pedigree studies were undertaken to test the cosegregation of an intragenic factor VIII marker with the disease phenotype. The study population consisted of 30 client-owned dogs (22 males and 8 females). Hemophilic males (n = 12) typically demonstrated prolonged bleeding after trauma or surgery rather than spontaneous hemorrhagic events. The affected males had a proportionate reduction in factor VIII coagulant activity (mean FVIII:C = 4%) and factor VIII protein concentration (mean FVIII:Ag = 3%). Twenty-five dogs (10 affected males, 8 clear males, 2 obligate carrier dams, and 5 suspect carrier daughters) were genotyped for a factor VIII microsatellite marker, with allele size assigned by an automated capillary electrophoresis system. Five distinct marker alleles were present in the study pedigree and a 300-base pair allele was found to segregate with the hemophilia A phenotype. The inheritance of the hemophilia-associated allele defined carrier status for 5 suspect daughters of obligate carrier dams. The limitations inherent to linkage analyses (i.e., lack of access to key family members and homozygosity at the marker locus) did not preclude carrier detection in this pedigree. We conclude that genotype analysis for the intragenic factor VIII marker can aid in control of canine hemophilia A through enhanced carrier detection.     

几种VA菌根真菌载体繁殖的比较测定

采用4种VA菌根菌种对红三叶草接种的实验表明，4种VA菌根对红三叶草都有一定程度的侵染，只是侵染率不同。根内球囊霉对红三叶草的感染率和感染强度比较高，地表球囊霉次之，摩西球囊霉和洛桑混合菌种的感染率和感染强度较低，说明前2种菌的繁殖效果较好，可继续扩大繁殖。