Siting restrictions and proximity of Concentrated Animal Feeding Operations to surface water

Proximity and connections to surface waters may play significant roles in determining impacts of manure spills. As occurred in many U.S. states, Minnesota adopted in 2000 more stringent regulations on Concentrated Animal Feeding Operations (CAFOs) including restrictions on siting new facilities near surface waters. The objectives of this study were to determine whether CAFO proximity to surface waters decreased following the siting restrictions and to evaluate implications of siting restrictions. Permit dates, locations, and distances to nearest surface water bodies for 111 west central Minnesota CAFOs were determined based on satellite imagery, historical records, and correspondence with regulatory officials. Average distance between surface waters and facilities permitted after 2000 was greater than for facilities permitted before 2000. The increase in average distance between CAFOs and public surface waters was significant for open water (1790 m, p = 0.03), but not for streams (280 m, p = 0.47). Decreased CAFO proximity to surface waters should benefit water quality, but after 2000 facilities continued to be permitted close to hydraulic connections not covered by the siting restriction. Comprehensive manure spill tracking and long term targeted water quality monitoring are needed to evaluate effectiveness of siting restrictions and other strategies for protecting surface waters from manure spills.     

Cu-Mn-Zr复合催化剂制备及其催化氧化乙酸乙酯性能

采用溶胶凝胶法制备了4种不同金属摩尔比的Cu-Mn-Zr复合催化剂，利用BET、XRD和XPS对其进行了表征分析，通过固定床管式反应器评价了其对乙酸乙酯模拟气体的催化活性，定性测定了其催化反应降解产物.结果表明，Mn的加入增大了催化剂的比表面积和总孔容，催化剂的N₂吸附-解吸等温线为IV型.Cu-Zr（1：1）催化剂观察到氧化铜晶体和四方晶型氧化锆晶体，氧化铜晶体随着Cu比例的减小而降低，Mn的加入导致氧化锆晶体消失.催化剂无固定形态，呈现良好的分散性.增大Mn/Zr摩尔比能提高催化活性.Cu-Mn-Zr的适当组分比能提高其低温催化活性，其中Cu-Mn-Zr（1：1：1）催化剂的低温催化活性与CO₂的选择性较佳，在200℃时对CO₂的选择性达到96.7%.降解产物分析表明，乙酸乙酯降解中间产物有乙酸和乙醇，最终降解产物主要有CO₂和H₂O等.     

Azadirachtin induced changes in feeding,dietary utilization and midgut carboxylesterase activity of the final instar larvae of spodoptera litura (fabricius) (lepidoptera: Noctuidae)

Abstract

Final (sixth) instar larvae of Spodoptera litura were fed in increasing amounts of azadirachtin and the effects on feeding activity, dietary utilization and mid‐gut carboxylesterase activity were determined. The antifeedant activity of azadirachtin did not increase in a dose‐dependent manner as reflected by the decline in antifeedant effect at higher doses of 30 and 50 ppm. Dietary concentrations of azadirachtin although significantly lowered the efficiencies of conversion of both ingested (ECI) and digested (ECD) food, it failed to lower the approximate digestibility (AD). The latter however, increased significantly with increasing concentrations of azadirachtin. Feeding of higher doses (30 and 50 ppm) resulted in significant increase in midgut carboxylesterase activity. Thus insensitivity to antifeedant effects and induction of midgut carboxyesterase activity in the older larvae of S.litura In response to high doses of azadirachtin observed in this study can have adverse consequences unless particular attention is paid in developing application strategies for azadirachtin based biopesticides for use in pest control protocols.     

Is asynchronous hatching adaptive in herring gulls (Larus argentatus)?

Hatching asynchrony commonly induces a size hierarchy among siblings and the resultant competition for food between siblings can often lead to starvation of the smallest chicks within a brood. We created herring gull (Larus argentatus) broods with varying degrees of hatching synchrony by manipulating the timing of incubation while maintaining the originally laid eggs. The degree of hatching asynchrony affected sibling size hierarchy at the time of hatching of the last-hatched ”c-chick.” In unmanipulated broods, there was no disadvantage of being a c-chick. However, when asynchrony was experimentally increased, we found reduced survival of the c-chick only in the exaggerated asynchronous experimental group. The effects were observable only during the first 10 days of chick life. We recorded no cases of the chicks dying of starvation. Furthermore, behavioral observations indicated that there was no sibling competition, and no selective feeding of larger sibs in the study colony. We propose that the observed lower survival rates of c-chicks in exaggerated asynchronous broods resulted from their lesser motor abilities, affecting their chances of escaping predators. Fledging success for the whole colony was generally high and almost half of all pairs fledged all three chicks, which is indicative of a good feeding environment. We argue that normal hatching asynchrony is a favorable solution in a good feeding environment, but that increased asynchrony reduces breeding success. We do not view asynchrony in the herring gull as an adaptation for brood reduction and propose instead that it may come about because there has been selection for incubation to start before clutch completion. Received: 14 April 1999 / Received in revised form: 20 October 1999 / Accepted: 23 January 2000     

Ecological and social determinants of spacing behaviour in desert baboon groups

This paper investigates the determinants of individual spacing behaviour in a desert baboon population (Papio cynocephalus ursinus). Patterns of neighbour proximity and neighbour density were examined among adults in four groups under different ecological and social conditions (through instantaneous sampling during focal follows). Initial analysis of these data shows that (1) the use of vertical substrates (refuges such as tall trees and cliff faces) can confound patterns of spacing, and (2) individual differences in spacing can depend on the spatial scale over which it is measured. To minimise these substrate and scale effects, this analysis focuses on animals which are off refuges and examines spacing behaviour through its underlying statistical `dimensions' (identified through factor analysis). Analysis of these dimensions indicates that sex, group size, activity-habitat and female reproductive state can all have independent effects on spacing: (1) males are more dispersed than females in smaller groups, (2) male and female dispersion increases with time spent in foraging habitats, and (3) female dispersion is reduced during lactation. According to the hypotheses tested, these results indicate that feeding competition only affects spacing behaviour during foraging while predation risk plays little or no role in spacing. Most aspects of spacing behaviour are best explained by male reproductive strategies and their social repercussions. Received: 25 May 1998 / Accepted after revision: 18 July 1998     

Antiradical activity of natural honeys and antifungal effect against Penicillium genera

The purpose of the study was to examine the antiradical activity of 11 natural honeys and to evaluate the antifungal properties of honey. Honey samples (10) were collected from different locations of Slovak Republic. Honeys were native to different plant species of Robinia pseudoacaccia, Brassica napus subs. napus, Castanea sativa Mill. Thymus serpyllum vulgaris and the other samples had multifloral origin. The low antiradical activitity in honey samples was determined. The best results were found in thyme honey from Rhodos (11.84 %) and Castanea honey from Nitra (10.61 %). The lowest antiradical activity was found in Acacia honey and determined to be 7.62 %. Statistically significant differences (P< 0.001) were found among thyme/Rhodos and Castanea/Nitra. The antifungal activities of honey samples were tested by 10 %, 25 % and 50 % (by mass per volume) concentration against fungi Penicillium crustosum, P. expansum, P. griseofulvum, P. raistrickii and P. verrucosum and by the agar well diffusion method. The solutions containing 10 % (by mass per volume) of honey did not have any effect on the growth of fungi. The strongest antifungal effect was shown by 50 % honey concentration against P. raistrickii.     

Changes in biomass activity and characteristics of activated sludge exposed to low ozone dose

In this paper, the response mechanism of activated sludge exposed to low-dose ozone at less than 20 mg O₃ g⁻¹ total suspended solids (TSS) was studied by analyzing the changes in sludge activity and the evolution of C, N, P and metals from sludge following ozonation. The intracellular ATP concentration was not affected at less than 5 mg O₃ g⁻¹ TSS and thereafter decreased rapidly to around 60% when the ozone dose increased to 20 mg O₃ g⁻¹ TSS. Similarly, the efficiency of sludge solubilization initially changed a little and then increased rapidly to around 30% at an ozone dose of 20 mg O₃ g⁻¹ TSS. However, the activities of superoxide dismutase and protease decreased immediately upon exposure to ozone. These findings indicate that ozone firstly destroys the floc, leading to the disruption of the compact aggregates, which does not affect cells viability but induces a decrease in enzyme activities. Ozone then attacks the bacterial cells of the sludge, causing a decrease in cells viability. During ozonation, the content of carbon, nitrogen and phosphorus in the sludge matrix decreased, while the content of these elements in the micro-solids and supernatant gradually increased. Most of the released metals from the sludge matrix were found in the micro-solids.     

蚯蚓处理对污泥中微生物碳量及脱氢酶活性的影响

将含水率80.6%的脱水污泥制成5 mm的污泥颗粒,以添加蚯蚓(赤子爱胜蚓)为处理组,无蚯蚓为对照组,测定不同时期污泥的理化性质、微生物碳量(MBC)和脱氢酶活性(DHA)的变化,重点研究了蚯蚓对污泥降解过程中MBC和DHA变化的影响.结果表明,相比对照组,蚯蚓处理组p H变化幅度较小;实验结束时,蚯蚓处理组的电导率(EC)和溶解性有机碳(DOC)显著高于对照组,而有机质(OM)显著低于对照组.实验前30 d,蚯蚓处理组MBC显著高于对照组,40 d至实验结束,蚯蚓处理组MBC显著低于对照组.DHA的结果表明,蚯蚓处理组和对照组在前30 d并没有显著性差异,40 d后蚯蚓处理组的DHA显著低于对照组,DHA稳定在2.98~6.40 mg·g-1·h-1(以TPF计).相关分析表明,DHA、MBC和OM之间显著正相关.研究表明,接种蚯蚓在实验前期显著提升了系统的微生物量,加快污泥有机质的降解,从而导致后期产物的微生物量及其活性较低,最终产物更稳定.     

降解剩余污泥中纤维素/半纤维素微生物富集培养实验研究

为促进剩余污泥中木质纤维素能源转化,首先需要探知污泥中是否存在可以降解纤维素/半纤维素的微生物.以木聚糖作为单一碳源分别从剩余污泥和厌氧消化污泥中富集培养可降解纤维素/半纤维素的微生物.实验结果显示,两种污泥源中均存在可降解纤维素/半纤维素的微生物,并可成功富集培养获得该类微生物.FISH与LIVE/DEAD实验证实,富集微生物为梭状芽孢杆菌属和芽孢杆菌属的混合物,并以梭状芽孢杆菌为主;富集微生物均具有很高活性.     

玉米对铅胁迫的响应及体内铅化学形态研究

通过砂培试验,研究了铅(Pb)胁迫下不同品种玉米根、茎叶中Pb的化学形态变化,进一步探讨玉米耐Pb机制.结果表明,本试验中对Pb胁迫耐性最强的玉米品种为郑单958和隆平206,耐性最差的为联创5号.不同浓度Pb胁迫下玉米根、茎叶中Pb主要以无毒的醋酸提取态和盐酸提取态为主,比例高达60%~87%,这一比例根部略高于茎叶;而活性较强的乙醇提取态和水提取态Pb含量两者合计所占比例为6%~20%.100 mg·L-1Pb胁迫下隆平206茎叶中Pb的乙醇和水提取态合计值最低(0.52 mg·kg-1),其次是郑单958(0.93 mg·kg-1),最高的为联创5号(2.78 mg·kg-1);800 mg·L-1Pb胁迫下,郑单958茎叶中Pb的乙醇提取态和水提取态合计值最低,为2.41 mg·kg-1,因此郑单958耐Pb,可能与体内有毒形态Pb向无毒形态Pb的转换有关.