Tetracycline resistance in semi-arid agricultural soils under long-term swine effluent application

Annually, millions pounds of antibiotics are released unmetabolized into environment along with animal wastes. Accumulation of antibiotics in soils could potentially induce the persistence of antibiotic resistant bacteria. Antibiotics such as tetracyclines and tetracycline-resistant bacteria have been previously detected in fields fertilized with animal manure. However, little is known about the accumulation of tetracyclines and the development of tetracycline resistance in semi-arid soils. Here we demonstrate that continuous land application with swine effluent, containing trace amounts of chlortetracycline, does not necessarily induce tetracycline resistance in soil bacteria. Based on the testing of more than 3,000 bacteria isolated from the amended soils, we found no significant increase in the occurrence and level of chlortetracycline resistant bacteria in soils after 15 years of continuous swine effluent fertilization. To account for a possible transfer of tetracycline-resistant bacteria originated from the swine effluent to soils, we analyzed two commonly found tetracycline resistant genes, tet(O) and tet(M), in the swine effluent and fertilized soils. Both genes were present in the swine effluent, however, they were not detectable in soils applied with swine effluent. Our data demonstrate that agronomic application of manure from antibiotic treated swine effluent does not necessarily result in the development of antibiotic bacterial resistance in soils. Apparently, concentrations of chlortetracycline present in manure are not significant enough to induce the development of antibiotic bacterial resistance.     

Recognizing animal personhood in compassionate conservation

Compassionate conservation is based on the ethical position that actions taken to protect biodiversity should be guided by compassion for all sentient beings. Critics argue that there are 3 core reasons harming animals is acceptable in conservation programs: the primary purpose of conservation is biodiversity protection; conservation is already compassionate to animals; and conservation should prioritize compassion to humans. We used argument analysis to clarify the values and logics underlying the debate around compassionate conservation. We found that objections to compassionate conservation are expressions of human exceptionalism, the view that humans are of a categorically separate and higher moral status than all other species. In contrast, compassionate conservationists believe that conservation should expand its moral community by recognizing all sentient beings as persons. Personhood, in an ethical sense, implies the individual is owed respect and should not be treated merely as a means to other ends. On scientific and ethical grounds, there are good reasons to extend personhood to sentient animals, particularly in conservation. The moral exclusion or subordination of members of other species legitimates the ongoing manipulation and exploitation of the living worlds, the very reason conservation was needed in the first place. Embracing compassion can help dismantle human exceptionalism, recognize nonhuman personhood, and navigate a more expansive moral space.     

Potential treatments to reduce phorbol esters levels in jatropha seed cake for improving the value added product

Jatropha seed cake contains high amounts of protein and other nutrients, however it has a drawback due to toxic compounds. The aim of this study was to investigate the methods applied to detoxify the main toxin, phorbol esters in jatropha seed cake, to a safe and acceptable level by maintaining the nutritional values. Phorbol esters are tetracyclic diterpenoids-polycyclic compounds that are known as tumor promoters and hence exhibited the toxicity within a broad range of species. Mismanagement of the jatropha waste from jatropha oil industries would lead to contamination of the environment, affecting living organisms and human health through the food chain, so several methods were tested for reducing the toxicity of the seed cake. The results from this investigation showed that heat treatments at either 120°C or 220°C for 1 hour and then mixing with adsorbing bentonite (10%), nanoparticles of zinc oxide (100 μg/g) plus NaHCO₃ at 4%, followed by a 4-week incubation period yielded the best final product. The remaining phorbol esters concentration (0.05–0.04 mg/g) from this treatment was less than that reported for the nontoxic jatropha varieties (0.11–0.27 mg/g). Nutritional values of the seed cake after treatment remained at the same levels found in the control group and these values were crude protein (20.47–21.40 + 0.17–0.25%), crude lipid (14.27–14.68 + 0.13–0.14%) and crude fiber (27.33–29.67 + 0.58%). A cytotoxicity test conducted using L929 and normal human dermal fibroblast cell lines confirmed that most of the toxic compounds, especially phorbol esters, were shown as completely eliminated. The results suggested that the detoxification of phorbol esters residues in the jatropha seed cake was possible while it also retained nutritional values. Therefore, the methods to detoxify phorbol esters are necessary to minimize the toxicity of jatropha seed cake. Further, it is essential to reduce the possible environmental impacts that may be generated throughout the jatropha waste-handling process. However additional tests such as digestibility as well as acceptability of the treated jatropha seed cake should be conducted using both in vivo and in vitro studies before recommending the jatropha seed cake as a source of renewable animal feed and other value-added products.     

19种动植物粗提物对锦鲤诱食活性的研究

以16种植物和3种动物提取物作为实验材料,以体长为3—5cm的锦鲤为实验对象,采用触球法进行诱食活性研究,5次重复试验,并利用SPSS软件进行分析。结果表明,大蒜、浒苔、洋葱、西红柿、江蓠、陈皮、橙子、山楂、紫菜提取物和海星、海蜇、牡蛎提取物对锦鲤显示出诱食反应。其中,大蒜P=0.0010.05、浒苔P=0.0020.05、江蓠P=0.0040.05、陈皮P=0.0370.05、海星P=0.0030.05,说明大蒜、浒苔、江蓠、陈皮、海星对锦鲤的诱食反应有显著意义。     

Responses of CH(4), CO(2) and N(2)O fluxes to increasing nitrogen deposition in alpine grassland of the Tianshan Mountains

To assess the effects of nitrogen (N) deposition on greenhouse gas (GHG) fluxes in alpine grassland of the Tianshan Mountains in central Asia, CH₄, CO₂ and N₂O fluxes were measured from June 2010 to May 2011. Nitrogen deposition tended to significantly increase CH₄ uptake, CO₂ and N₂O emissions at sites receiving N addition compared with those at site without N addition during the growing season, but no significant differences were found for all sites outside the growing season. Air temperature, soil temperature and water content were the important factors that influence CO₂ and N₂O emissions at year-round scale, indicating that increased temperature and precipitation in the future will exert greater impacts on CO₂ and N₂O emissions in the alpine grassland. In addition, plant coverage in July was also positively correlated with CO₂ and N₂O emissions under elevated N deposition rates. The present study will deepen our understanding of N deposition impacts on GHG balance in the alpine grassland ecosystem, and help us assess the global N effects, parameterize Earth System models and inform decision makers.     

环青海湖地区草地蝗虫发生的生态环境条件分析

为了有效地进行草地蝗虫的防治,必须摸清其生长和繁殖与生态环境条件的关系。研究表明,在环青海湖地区气温对草地蝗虫影响较为明显是在蝗卵越冬期和孵化期。降水量太多不利于草地蝗虫的发育,但降水适量因有利于蝗蝻出土可能会增加蝗虫基数。青海湖级湖成阶地和构造台地有利于蝗虫的繁育。土壤的温度、质地及水分和盐分含量对草地蝗虫的发生和繁育也有一定影响。     

2019年锡林郭勒盟肉羊天气指数型保险浅析——以内蒙古西乌珠穆沁旗为例

天气指数型保险是一种创新型保险,肉羊天气指数型保险以牲畜草料为保险标的,为牧民提供因旱灾、雪灾所造成的肉羊饲养成本增长及因天气灾害致损的保险保障和风险对冲,即每当天气达到气象灾害标准时统一按投保合同中数量进行赔付.同时,天气指数型保险的实施也大大降低了保险公司查勘定损的成本和被保险人道德风险的危害.2019年,肉羊天气...     

佛坪自然保护区野生动物资源的开发与利用

作为国家级的佛坪自然保护区蕴藏着丰富的野生动物资源。本文从动物资源的历史与现状分析,对合理开发利用佛坪自然保护区的野生动物资源进行了探讨     

Predicting the variation in detection function in line transect sampling through random parameter model

A method for calibrating (localizing) detection function models in line transect sampling is proposed. The method is based on a random parameter model which supplies localized predictions of detection function parameters utilizing a few sample data points from the concerned location(s). The method has the clear advantage of being able to provide density estimates based on very few observations from a location which would be impossible through traditional methods. The method is successfully illustrated using census data on sambar (Cervus unicolor) from a set of wildlife sanctuaries in Kerala, India. The need for further research in this direction is indicated.     

基于土地利用变化模型的退耕还林还草决策分析——以通辽地区为例

通过综合考虑影响退耕还林还草的自然和社会因素,结合土地利用规划和遥感影像解译结果,论文以通辽地区为例,介绍了利用土地利用变化模型确定退耕还林还草区域的方法和过程。根据对2010年模型模拟结果和2000年通辽地区土地利用现状的对比分析,结果发现2000～2010年该地区进行退耕还林还草的合适区域应该主要位于研究地区的中部、南部,以及北中部。研究地区中部属于科尔沁沙地的腹地,土地沙漠化最为严重,同时城镇和农村居民点分布较密,退耕还林还草是政府用于减缓风沙对城镇和农村居民点危害程度的重要生态措施;而南部和北中部属于丘陵和山区,由于过度开垦,水土流失较为严重,是实施退耕还林还草的重点区域。此外,与退耕还林区相比,退耕还草区距城镇、农村居民点以及道路相对较远,具有可达性较差、地理位置较为偏僻的特点。论文得出的结果可为今后通辽地区退耕还林还草工程的实施提供科学依据,同时,该文提出的确定退耕还林还草区域的方法对其它地区具有一定的借鉴意义。