Density estimates of rural dog populations and an assessment of marking methods during a rabies vaccination campaign in the Philippines

We estimated the population density of dogs by distance sampling and assessed the potential utility of two marking methods for capture-mark-recapture applications following a mass canine rabies-vaccination campaign in Sorsogon Province, the Republic of the Philippines. Thirty villages selected to assess vaccine coverage and for dog surveys were visited 1 to 11 days after the vaccinating team. Measurements of the distance of dogs or groups of dogs from transect lines were obtained in 1088 instances (N = 1278 dogs; mean group SIZE = 1.2). Various functions modelling the probability of detection were fitted to a truncated distribution of distances of dogs from transect lines. A hazard rate model provided the best fit and an overall estimate of dog-population density of 468/km² (95% confidence interval, 359 to 611). At vaccination, most dogs were marked with either a paint stick or a black plastic collar. Overall, 34.8% of 2167 and 28.5% of 2115 dogs could be accurately identified as wearing a collar or showing a paint mark; 49.1% of the dogs had either mark. Increasing time interval between vaccination-team visit and dog survey and increasing distance from transect line were inversely associated with the probability of observing a paint mark. Probability of observing a collar was positively associated with increasing estimated density of the dog population in a given village and with animals not associated with a house. The data indicate that distance sampling is a relatively simple and adaptable method for estimating dog-population density and is not prone to problems associated with meeting some model assumptions inherent to mark-recapture estimators.     

家蚕产卵量的基因效应参数估计

用产卵量差异较大的两个近交系782和Ekp作亲本,配制了F1、F2正反交及F1与两亲本的回交B1和B2,加上两亲本P1和P2共8个世代,采用多世代平均值的多元回归分析方法对产卵量的基因效应参数进行了估计,得到了如下结果：（1）建立了分析家蚕产卵量的常染色体基因加性、显性和性染色体基因加性效应的非二体遗传模型,并通过实际数据检验表明产卵量遗传符合这个模式;（2）产卵量的遗传主要取决于常染色体上基因加性效应,其次是性染色体基因加性效应,显性效应很小。     

Small area estimations of proportion of forest and timber volume combining Lidar data and stereo aerial images with terrestrial data

Abstract

Methods for small area estimations were compared for estimating the proportion of forest and growing stock volume of temperate mixed forests within a district of a member state (canton) in Switzerland. The estimators combine terrestrial data with remotely sensed auxiliary data. By using different model types, different sources of auxiliary data and different methods of processing the auxiliary data, the increase in estimation precision was tested. Using the canopy height derived from remote sensing data, the growing stock volume and the proportion of forest were estimated. The regression models used for the small area estimation provided a coefficient of determination of up to 68% for the timber volume. The proportion of plots correctly classified into forest and non-forest plots ranged between 0.9 and 0.98. Models calibrated over forest area only resulted in a maximal coefficient of determination of 37%. Even though these coefficients indicate a moderate model quality, the use of remote sensing data clearly improved the estimation precision of both the proportion of forest and the growing stock volume. Generally, Lidar data led to slightly higher estimates compared to data from aerial photography. It was possible to reduce the variance of the estimated proportion of forest to nearly one tenth compared with the variance based on the terrestrial measurements alone. Similarly, the variance of the growing stock volume could be reduced to one fourth as compared with the variance based solely on the terrestrial measurements.     

THE INFLUENCE OF TYLOSES ON THE MANUFACTURE OF MATCHES

This article deals with the results of time studies of pruning P. radiata from 22 ft. to 35 ft. with pole saws. The influence on pruning time of mean diameter and number of branches removed in the pruning operation, number of cones removed and time of day is investigated and a multiple regression equation, expressing the relationship between pruning time and these variables, is computed. A taper table is prepared and used to investigate the effect of pruning on the formation of knot-free timber. The economics of high-pruning is discussed.     

论搞活山地流转机制是林业发展之路

搞活山地流转机制，推行林业适度规模经营，是由当前社会大环境和林业自身的特点所决定的。本文在论述搞活山地使用权流转机制时调动林农积极性、发展林业和振兴经济的作用的同时，进一步分析了山地使用权流转的各种形式，并指出评价山地使用权流转形式好坏的标准，是坚持“三个有利于”的标准。     

最佳线性无偏预测估计种畜育种值（BLUP）可视化计算机程序

应用VB6可视化编程软件，设计较先进的最佳线性无偏预测估计种畜育种值（BLUP法）程序，增强了软件的功能，使其更具易用性、广泛性。     

淳安县森林资源资产评估工作的初步构想

从分析森林资源资产评估的基本概念入手，根据林业分类经营思想提出开展淳安县森林资源资产评估工作的初步构想，指出了该县森林资源资产评估急需解决的几个问题     

泡桐属植物育种值预测方法的研究

分别用最佳线性无偏预测和最佳线性预测方法预测了泡桐属植物的育种值。结果表明，根据亲缘相关距阵对育种值的最佳线性无偏预测结果没有显著影响：数据量较大时，可用小区平均值取代单株值，同时也可用最佳线性预测代替最佳线性无偏预测方法预测育种值；预测育种值与真正育种值之间的相关系数与预测育种值之间的方法或误差方差存在极显著的相关关系，可用前者作预测育种值的精度指标。通过比较毛泡桐种源所预测育种值之间的方差和误差方差可以得出：在对研究材料评选时，最佳线性预测比最小平方估算法具有优越性，但当重复数大于5次，每个小区内的植株多于6时，这两种预测方法的精度非常接近。     

Validation of a small-area method for estimating the spatial distribution of the degree of tree damage

This article presents a validation of a method, proposed in Podlaski (2003), for estimating the degree of tree damage. This method belongs to a group of small-area methods. To estimate the degree of tree damage in individual P₃ sub-blocks of the SINUS system of information on the natural environment, a classification based on the degree of defoliation was used. Spatial distribution of the degree of tree damage was estimated through unrestricted simple random sampling. The maximum total estimation error for proportions of fir and beech with a damage degree of zero, and also with second and third degrees jointly, reached a maximum of 35.6% for fir, and 33.8% for beech. P₃ sub-blocks characterised by the highest proportion of the healthiest trees (at least 15% being undamaged trees) occurred in patches in the case of fir, and in larger, compact areas in the case of beech. Because spatial diversification in the health of fir, and to a smaller degree in the case of beech, occurs at small scales, small-area methods for estimating tree condition are necessary. An analogous scheme, combining small-area with large-area methods (utilising sub-blocks of the network of large-area systems in a small-area inventory, and establishing a common database), could be used on a wider scale; for example, by supplementing the program of estimating tree health carried out by the United Nations Economic Commission for Europe (Lorenz et al. 2002) with local inventories.