Publications Exchange at the National Agricultural Library

ABSTRACT

A brief overview is provided of the policies, responsibilities, procedures and current projects of the Gift and Exchange Unit of the National Agricultural Library (NAL). Exchange operations which formed a part of the earliest library traditions of the U.S. Department of Agriculture now aid NAL in meeting the challenges of acquisitions operations which must adapt continually during an era of rapid technological change and stringent funding.     

Microbial biogeography at the soil pore scale

Microbial communities exist and are active in a complex 3-D physical framework which can cause a variety of micro-environments to develop that are more or less suitable for microbial growth, activity and survival. If there is a significant microbial biogeography at the pore scale in soil, then the relationship between microbial diversity and ecosystem function is likely to be affected by micro-environmental variations at the pore scale. In this laboratory study we show that there is a significant pore-scale microbial biogeography by labelling microbial communities in different pore size classes of undisturbed soil cores with ¹³C-labelled fructose (a soluble, labile substrate). This was achieved by adding the substrate solution to the samples at different matric potentials (−100 kPa, −3.15 kPa and −1 kPa; placing the substrate in pores with maximum diameter of 0.97, 9.7 and 97 μm, respectively) and incubating the samples for two weeks. The mineralisation of soil organic carbon and fructose was measured as CO₂ and ¹³C-CO₂, respectively, in the jar headspace throughout the incubation. At the end of incubation we analysed the total microbial community structure using PLFA. The structure of microbial communities in different pore size classes was measured by PLFA stable isotope probing. Total PLFA profiles suggested that there was little effect of the incubation conditions on microbial community structure. However, labelled PLFA profiles showed that microbial community structure differed significantly among pore size classes, the differences being due primarily to variations in the abundance of mono-unsaturated lipids (Gram-biomarkers) and of the fungal biomarker (C18:2(9,12)). This is the first evidence for a significant microbial biogeography at the pore scale in undisturbed soil cores.     

Is Artificial Light at Night Dangerous for the Balkan Strict Protected Areas at Present?

Water, Air, & Soil Pollution - In this study, a new composite membrane has been prepared by means of blending with maifanite (MFS), activated alumina (AA), and poly(vinylidene fluoride) (PVDF)...     

Modelization of the mercury fluxes at the air-sea interface

Aqueous and atmospheric Hg° concentrations for remote marine areas such as the equatorial Pacific Ocean and for coastal seas such as the North Sea and the Scheldt Estuary are discussed. Biological processes seem to be at the origin of the supersaturated Hg° concentrations in the water. On the other hand, transfer velocities across the air-sea interface were calculated with a classical shear turbulence model and with a wave breaking model. With these data, Hg° fluxes from the sea to the atmosphere were calculated: in the Pacific Ocean they range from 0.43 to 6.5 μg g Hg.m^?2. yr^?1 at a wind speed of 2.8 m.s^?1 and from 10.3 to 156 μg Hg.m^?2 yr^?1 at a wind speed of 54 m.s^?1, but they are still higher when wave breaking is considered (from 11 to 168 μg Hg.m^?2.yr^?1). These transfer fluxes are an order of magnitude higher in the Scheldt Estuary.     

Effect of rain on the macroporosity at the soil surface

Rain falling on soil causes slaking, mechanical disruption of aggregates and compaction. Too few data exist to predict the changes likely to occur in particular soil, landscape and management conditions. Experiments with simulated rain were set up to study and to model mathematically the changes of the pore system within the surface layer of a soil when rain was applied on a field cropped with maize. Macroporosity, pore‐size and pore‐shape distributions, and the pore volume were measured by image analysis of thin sections and the fractal dimensions of the pore surface roughness were estimated. The general trends of changes in porosity indicated the presence of two different sets of processes at the surface (0–3 cm) and in the layer immediately underneath (3–6 cm). In both layers most of the variation in macroporosity was due to a loss of elongated porosity. A theoretical approach recently developed to link rain and erosion to sealing properties was extended to describing the effect of rain on the elongated porosity and the pore volume fractal dimension in these two layers. The resulting set of equations describe in detail the evolution of soil porosity near the soil surface. Our approach could be useful when modelling the effects of sealing processes in soil erosion.     

Particle-stabilizing effects of flavonoids at the oil-water interface

It has been shown that some common food flavonoids can act as excellent stabilizers of oil-in-water emulsions through their adsorption as water-insoluble particles to the surface of the oil droplets, i.e., Pickering emulsions are formed. Flavonoids covering a wide range of octanol-water partition coefficients (P) were screened for emulsification behavior by low shear mixing of flavonoid+n-tetradecane in a vortex mixer. Most flavonoids with very high or very low P values were not good emulsifiers, although there were exceptions, such as tiliroside, which is very insoluble in water. When a high shear jet homogenizer was used with 20 vol% oil in the presence of 1 mM tiliroside, rutin, or naringin, much finer emulsions were produced: the average droplet sizes (d32) were 16, 6, and 5 μm, respectively. These results may be highly significant with respect to the delivery of such insoluble compounds to the gut, as well as their digestion and absorption.     

Pedodiversity on Soil Maps at the District Level

Eurasian Soil Science - The analysis of soil maps for three districts of Bryansk oblast demonstrates that the rank distributions of polygon areas for low soil taxonomic units on these maps have a...     

Air pollution measurements at the boulder atmospheric observatory

Pollution episodes of three distinct types were detected at the Boulder Atmospheric Observatory, which is a 300 m instrumented tower located in a rural area 25 km north of Denver and 20 km east of Boulder. Under stably stratified atmospheric conditions, usually at night or early morning, both power-plant-derived and general urban plumes were sampled. The powerplant plumes were characterized by SO₂ concentrations of 30 to 50 ppb in the plume centers, NO₂ maxima of 20 to 40 ppb on the plume edges, NO maxima of as much as 50 ppb in the plume centers, and the absence of O₃ from the plume centers. Light scattering (b _scat), principally due to coarse particles, was typically enhanced by 20 to 40%, relative to nominally clean air. The urban plumes typically contained NO₂ uniformly distributed throughout the affected air mass at 20 to 30 ppb, no detectable NO or SO₂, and O₃ present at concentrations less than half that in background air; b _scat was typically increased by a factor of 2 to 3. A third type of pollution episode, containing greatly increased concentrations of condensation nuclei, was observed during days when surface heating had apparently stimulated biological particle production. At these times the usual indicators of anthropogenic pollution were absent.     

Reducing runoff by managing crop location at the catchment level,considering agronomic constraints at farm level

Runoff and erosion cause frequent damage through muddy floods in the loess belt of Northern Europe. One possibility for reducing damage is to lower runoff on agricultural land by spatially alternating different crops at the catchment level. But crop location results from decisions taken at the farm level. This study aimed to assess the existing leeway to modify crop location in the farms of a catchment, in order to reduce runoff at the catchment's outlet. The case study was the Bourville catchment (1086 ha), cultivated by 28 farmers and located in Pays de Caux, France. First, crop location rules in the 14 main farms of the catchment were analysed on the basis of surveys carried out with farmers, distinguishing spatial constraints from temporal ones. These rules made it possible to simulate crop location on each farm territory for the 2001–2002 crop year. Each field of the catchment was classified depending on whether one or several crops could be sown, taking into account both field history and farmer decision rules. Then two extreme scenarios of crop location in the Bourville catchment were built. Runoff simulation at the outlet with the STREAM model showed that runoff could be reduced while sticking to current farmer decision rules in terms of crop location. Depending on rainfall event characteristics, runoff reduction varied between 13·5 per cent and 4·5 per cent. Copyright © 2006 John Wiley & Sons, Ltd.     

拔节-孕穗期淹涝胁迫对水稻生长的后效影响

为探究每年7-8月（拔节-孕穗期）洪涝淹没对水稻生长的后效影响,以Ⅱ优898为试验对象,在安徽新马桥农水试验站开展为期2 a的水稻淹涝胁迫试验。试验设置了具有不同淹水深度（半淹、3/4淹、全淹）和淹水持续时间（5、7、9 d）组合的9个试验组,以及正常控水的对照组。在淹水胁迫结束后,对后胁迫时期水稻的叶片光合特性、根系生长情况、植株干物质分配和相应产量进行了多次观测。结果表明,淹涝胁迫在一定程度上抑制了叶片气孔导度和光合速率,但在胁迫解除后会逐渐恢复甚至出现补偿现象,其恢复进程受前期淹涝程度影响。淹涝胁迫使水稻的干物质分配策略更倾向于叶和茎,并随着前期淹涝程度加重而愈发明显;在复水后第20天,半淹组的平均茎叶干物质分配系数相比于对照组增加了7.9%,而全淹组则增加了32.9%。水稻产量与其在后胁迫时期的茎叶干物质分配系数存在显著的相关关系,相关系数为0.875（P=0.023）;水稻产量随着茎叶干物质分配系数的增加、叶片气孔导度和光合速率的减小而减少。该研究针对拔节-孕穗期发生的淹涝胁迫,重点对后胁迫时期水稻的光合特性及干物质分配策略进行了分析,初步探讨了水稻涝害减产的潜在机理,为提出稻田涝后减灾管理措施提供了一定的理论依据。     

Classifying soils at the ultimate stage of weathering in the tropics

Oxisols cover ≈ 23% of the land surface in the tropics and are utilized extensively for agricultural purposes in the tropical countries. Under the variable input types of agricultural systems practiced locally, some of these soils still appear to have problems in terms of proper soil classification and subsequently hinder attempts to implement sustainable agro‐management protocols. The definition for Oxisols in Soil Survey Staff (1999) indicates that additional input is still required to refine the definition in order to resolve some of the outstanding classification problems. Therefore, the objective of this study is to examine the properties of some Oxisols and closely related soils in order to evaluate the classification of these soils. Soils from Brazil, several countries in Africa, and Malaysia were used in this study. Field observations provided the first indication that some of the presently classified kandi‐Alfisols and kandi‐Ultisols were closer to Oxisols in terms of their properties. Water‐retention differences and apparent CEC of the subsurface horizons also supported this idea. The types of extractable Fe oxides and external specific surface areas of the clay fractions showed that many kandic horizons have surface properties that are similar to the oxic horizons. Micromorphology indicated that the genetic transition from the argillic to the oxic involves a diminishing expression of the argillic. Properties, such as CEC, become dominant. The kandic horizon is therefore inferred as a transition to the oxic horizon. It is proposed that the Oxisols be keyed out based only on the presence of an oxic horizon and an iso–soil temperature regime. The presence of a kandic horizon will be reflected at lower levels in Oxisols. The Oxisols will now be exclusive to the intertropical belt with an iso–soil temperature regime. The geographic extend of the Oxisols would increase and that of kandi‐Alfisols and Ultisols would decrease. A few kandi‐Alfisols and Ultisols in the intertropical area will have low CEC which would fail the weatherable mineral contents. The kandic subgroups of some Alfisols and Ultisols will be transitional between the low (< 16 cmol_c [kg clay]^–1)‐ and high (> 24 cmol_c [kg clay]^–1)‐activity clay soils. The proposed changes to classification will contribute to a better differentiation of the landscape units in the field. Testing of the proposed classification on some Malaysian soils showed that the new definition for Oxisols provides a better basis for the classification of the local soils and the development of meaningful soil‐management groups for plantations.     

Analysis of beta-casein-monopalmitin mixed films at the air-water interface

The surface pressure (pi)-area (A) isotherms and Brewster angle microscopy (BAM) images of monopalmitin and beta-casein mixed films spread on buffered water at pHs 5 and 7 and at 20 degrees C were determined as a function of the mass fraction of monopalmitin in the mixture (X). The structural characteristics and morphology of monopalmitin-beta-casein mixed films are dependent on surface pressure, pH, and monolayer composition. The prevalence of monopalmitin in the interface increases with the amount of monopalmitin in the mixture and at higher pi. At the monopalmitin monolayer collapse the mixed film is practically dominated by the presence of monopalmitin. However, some degree of interactions exist between monopalmitin and beta-casein in the mixed film, and these interactions are more pronounced as the monolayer is compressed at the highest surface pressures.     

The modern radioecological situation at the Globus-1 site

This article is dedicated to analysis of the modern radioecological situation at the site of the Globus-1 peaceful nuclear explosion in the Ivanovo region. The variability of the ionizing radiation background, specific activity of ¹³⁷Cs and ⁹⁰Sr in the 0–20 cm soil layer, and dominant species of meadow vegetation near the site of the explosion are presented. Higher levels of ⁹⁰Sr contamination of plants in this territory and water from a research well were determined. The indices of contamination of the meadow biogeocoenosis components according to ¹³⁷Cs did not exceed the established norms.     

Adenylates in the soil microbial biomass at different temperatures

Five soils from temperate sites (Germany; 2 arable and 3 grassland) were incubated aerobically at 5, 10, 15, 20, 25, 35, and 40 °C for 8 days. Soils were analysed for soil microbial biomass C, biomass N, AMP, ADP, and ATP to determine whether the increase in the ATP-to-microbial biomass C ratio with increasing temperature was either due to an increase in the adenylate energy charge (AEC) or de novo synthesis of ATP, or both. Around 80% of the variance in microbial biomass C and biomass N was explained by differences in soil properties, only 7% by the temperature treatments. Averaging the data of all 5 soils for each incubation temperature, the microbial biomass C content decreased with increasing temperature from 15 to 40 °C continuously by 2.5 μg g⁻¹ soil °C⁻¹ after 8-days' incubation. However, this decrease was not accompanied by a similar decrease in microbial biomass N. The average microbial biomass C/N ratio was 6.8. Between 54 and 76% of the variance in AMP, ADP, ATP and the sum of adenylates was explained by differences in soil properties and between 14 (ADP) and 27% (ATP) by the temperature treatments. However, temperature effects on AMP and ADP were variable and inconsistent. In contrast, ATP and consequently also the sum of adenylates increased continuously from 5 to 30 °C followed by a decline to 40 °C. The AEC showed similarly a small, but significant increase with increasing temperature from 0.73 to 0.85 at 30 °C. Consequently, the majority of the variance, i.e. roughly 60% in AEC values, but also in ATP-to-microbial biomass C ratios was explained by the incubation temperature. The mean ATP-to-microbial biomass C ratio increased from 4.7 μmol g⁻¹ at 5 °C to a 2.5 fold maximum of 12.0 μmol g⁻¹ at 35 °C. This increase was linear with a rate of 0.26 μmol ATP g⁻¹ microbial biomass C °C⁻¹. The energy for the extra ATP produced during temperature increase is probably derived from an accelerated turnover of endocellular C reserves in the microbial biomass.     

A Serials Cancellation Project at the University of Kentucky

ABSTRACT

The state of serials publications in science, technology, and medicine has reached a crisis stage for academic libraries and librarians. Limited budgets have made it difficult to provide the latest research to faculty and students. This paper discusses the general background of the problem and efforts at the University of Kentucky to begin dealing with this crisis during its 2004–05 serials cancellation project. Also examined are the history of the serials problem in academic libraries and the complications and immediate outcomes of this particular cancellation project, along with questions and concerns that still need to be addressed.