Effect of diet on the feces quality in javan langur (Trachypithecus auratus auratus).

A high intake of easily fermentable carbohydrates and a low intake of fiber material are generally regarded as major factors affecting the health of captive langurs. The effect on fecal consistency of excluding fruits and vegetables from the diet was evaluated in Javan langurs (Trachypithecus auratus auratus). Cross-over trials were carried out at Rotterdam Zoo and at the Apenheul Zoo, The Netherlands. During the first and third dietary period, the langurs were fed their usual diet, which contained fruits, vegetables, langur pellets, and browse. During the second period, the vegetables and fruits were excluded from the diet and the diet essentially consisted of pellets and browse. Feces consistency was scored using a fecal score chart developed for langurs. During the second feeding period the feces consistency improved significantly in animals at both zoos. Across all trials, a firmer feces consistency was correlated with an increase in dietary cell wall (measured as neutral detergent fiber) and a decrease in dietary water. It is suggested that the combined decrease in the intake of soluble sugars, the increase of fiber intake, and a lower amount of dietary water in the diet resulted in more solid stools. The results indicate that a dietary neutral detergent fiber content of approximately 46% in dry matter will result in a feces consistency indicative of undisturbed gut function.     

Hygienic and ecological risks connected with utilization of animal manures and biosolids in agriculture

In recent years the fate of human and animal pathogen microorganisms as a potential pollutant of the environment has been paid increased attention. Substantial quantities of these compounds and their metabolites are excreted, flushed down the drain, discarded as waste, or left over in animal feedlots. After passing to the sewer, several of these compounds are not adequately eliminated by the methods that are currently used in sewage treatment. Substantial quantities of biosolids and livestock manure end up on agricultural land. Effective sanitation of the environment, particularly of some of its special parts, which can be a source of spreading of diseases, plays an important role in prevention of infectious diseases. In this respect special attention should be paid to the disinfection of infected farm animal excrements. Sanitation of excrements should, on the one hand, ensure effective inhibition of infectious agents and, on the other hand, comply with the requirement of preserving the composition of the manure so it can be used in agricultural production.     

Yields nutrient intake and soil fertilizing in 40 years fertilizer trials

The set of twenty long‐term field nutrition trials starting from 1957 at five sites. The sites differed by their altitude (from 180 m to 620 m) with average daily temperatures (from 6,8°C m to 9°C m) and soil type (from chernozem to brown podsolic soil) Provided mainly the following results:

? The geonomic division to the fertile sugarbeet region and less fertile potato region did not strictly differentiate the influence of fertilizer and climatic effects to the crop yields.

? The effect of fertilizing was dependent on the nutrient content and on the conditions of releasing and binding of the nutrients in soil.

? The precipitation regime has a strong influence on the effect of the nitrogen escalated doses.

? The facts concerning the nutrient intake are very precious knowledge. These facts have not been examined yet during the long‐term trials.

? The site effect, particularly its climatic conditions, on the nutrient intake is often more obvious compared to the fertilizing effect.

? Very interesting impulses for further research monitoring during the long‐term trials was contributed by “mapping”; of soil capacity to provide nutrients to plants at various sites and under different climate.     

A new microassay for antifeedants in<Emphasis Type="Italic"> Hylobius</Emphasis> pine weevils (Coleoptera)

A micro-feeding assay was developed for testing small amounts of synthetics and extracts as antifeedants for Hylobius pine weevils. We devised a simple setup consisting of 5×5-mm pieces of thin layer chromatography cellulose plates used in pairs for a bioassay involving choice. After application of 1.5 l solutions and evaporation of the solvent, each plate received a 5 l aliquot of 1 M sucrose as a feeding stimulant. The test period was 4 h at 25 °C with 6 days of starvation before the test, compared to just the 1 day sufficient for twig tests. Deprivation of water for 1 day at 65% RH before the test was critical because it increased feeding but not mortality. The combination of starvation and thirst reduced the relative variance (coefficient of variation) to below 50%. There was a good correlation of antifeedant activity in the microassay with the activity in a standard twig test. The microassay needs only several mg for a test series, whereas the twig test needs grams.     

红脂大小蠹高效引诱剂林间引诱试验结果初报

红脂大小蠹是原产北美近年传入我国的一种危险性森林害虫 ,生活隐蔽 ,防治难度很大。为筛选出对我国油松林中红脂大小蠹种群有高效引诱作用的药剂 ,为今后控制红脂大小蠹的危害提供经济、实用、高效的监测方法和防治技术提供技术和物质依据 ,作者于 2 0 0 2年 5～ 7月在石家庄井陉和邢台内丘两地 ,先后进行了连续 2次的引诱试验。试验以加拿大生产的商品和松节油分别作为对照 ,共对 2 7种不同药剂的林间引诱效果进行了测定。试验结果表明 ,2B -7号引诱剂引诱效果显著好于加拿大对照 (a=0 .0 1 4) ,每个诱捕器平均诱虫数量比加拿大引诱剂多 96.3 9%。初步测算其成本比购买加拿大产品低 3 0 %～ 5 0 %以上。     

Radial patterns of sap flow in woody stems of dominant and understory species: scaling errors associated with positioning of sensors

We studied sap flow in dominant coniferous (Pinus sylvestris L.) and broadleaf (Populus canescens L.) species and in understory species (Prunus serotina Ehrh. and Rhododendron ponticum L.) by the heat field deformation (HFD) method. We attempted to identify possible errors arising during flow integration and scaling from single-point measurements to whole trees. Large systematic errors of -90 to 300% were found when it was assumed that sap flow was uniform over the sapwood depth. Therefore, we recommend that the radial sap flow pattern should be determined first using sensors with multiple measuring points along a stem radius followed by single-point measurements with sensors placed at a predetermined depth. Other significant errors occurred in the scaling procedure even when the sap flow radial pattern was known. These included errors associated with uncertainties in the positioning of sensors beneath the cambium (up to 15% per 1 mm error in estimated xylem depth), and differences in environmental conditions when the radial profile applied for integration was determined over the short term (up to 47% error). High temporal variation in the point-to-area correction factor along the xylem radius used for flow integration is also problematic. Compared with midday measurements, measurements of radial variation of sap flow in the morning and evening of sunny days minimized the influence of temporal variations on the point-to-area correction factor, which was especially pronounced in trees with a highly asymmetric sap flow radial pattern because of differences in functioning of the sapwood xylem layers. Positioning a single-point sensor at a depth with maximum sap flow is advantageous because of the high sensitivity of maximum sap flow to water stress conditions and changes in micro-climate, and because of the lower random errors associated with the positioning of a single-point sensor along the xylem radius.     

Cutter head forces and load cell scanning

Among the machinery found in wood manufacturing industries, routers and planers are the most commonly used. These tools, which many times are mounted on metal cylinders, actually operate only briefly, i. e., when a chip is cut from a piece of wood under process. The rest of the time the knife follows the cylinder surface and a cycloid is formed relative to the work piece, which in turn is fed into the machine. A number of knives are mounted on the cutter, which ascertain that the planed surface will become sufficiently planed and does not show too a wavy pattern. This works fine for high revolutions and low feeding speeds even if problems sometimes occur. Factories, however, naturally want to increase the overall manufacturing speed, which means that at the same time more defects are introduced at the planed surface. These defects are the result of the cutting process. In this paper, we examine, by use of a load cell, how the cutting forces vary during the formation of a wood chip. Wood is not an isotropic material and knots and other anomalies make the evaluation harder. In order to simplify the conditions, experiments are also shown from the cutting of a plastic polymer material as well as Medium Density Fibreboard (MDF). It is shown that the work piece vibrated intensely which littered all output data from the cell. Experience from the experiments however made it possible to design a computerised filter which saved only those registrations which were of interest while the others were set to zero. For beech, the forces were found to be of the magnitude 50 N/cm opposite to the feeding direction while the tranverse forces changed signs and had a magnitude of about 5 N/cm.     

Leaf distribution in large trees and stands of the floodplain forest in southern Moravia

Vertical distributions of leaf dry mass (M(d)) and leaf area (A(f)) were related to relative irradiance (I(r); I(r) above the stand = 1) in closed-canopy, old-growth stands of the floodplain forest in southern Moravia composed largely of Quercus, Fraxinus and Tilia species. Foliage area and mass at any given canopy height were converted to solar equivalent leaf area (A(s)) and mass (M(s)) by multiplying actual values at a given level in the canopy by the relative irradiance at that position. Stand leaf area index (LAI) was 5 (7 including shrub and herb layer), and solar equivalent parameters reached about 25% of that amount. In all species, vertical profiles of both relative irradiance and leaf dry mass to area ratio (LMA) were sigmoidal and the two variables were linearly related. The dominant, upper canopy species had a larger proportion of solar equivalent foliage than suppressed understory species. For individual trees of all species, the upper canopy had a larger proportion of solar equivalent foliage than the lower canopy. Light compensation points at both the leaf and whole-tree level were defined according to leaf or tree position, size and structure. I conclude that optimization of A(s) for forest stands may be used as a basis for determining thinning schedules and evaluating tree survival after damage to tree crowns by various factors.