Maternal quality and differences in milk production and composition for male and female Iberian red deer calves (Cervus elaphus hispanicus)

Several theories predict a sex-biased investment either through unbalanced sex ratios in offspring or through differences in provisioning. According to them, one would expect an optimisation in indirect fitness, or else a compensation for increased mortality of one sex. In addition, biases in provisioning may also arise as a consequence of weight-dependent non-adaptive nutrient demands by offspring. This study examines milk provisioning and sex biases in offspring sex ratio together with maternal quality variables. Mothers of higher quality (weight and age) showed greater milk provisioning ability (in terms of production) resulting in greater calf weight gain. Mothers of sons produced greater yields of milk, milk protein, fat and lactose than mothers of daughters, and increased percentage of protein after controlling for higher male birth weight. In contrast, mothers of males did not differ from mothers of females in age or any body weight variables related to maternal quality. These results suggest that differences in milk production and composition for sons and daughters are rather a mechanism to optimise indirect fitness than a mechanism to compensate for increased mortality in male calves, or a consequence of greater weight-dependent nutrient demands by heavier male calves. Results also suggest that biases in milk provisioning may occur without biases in offspring sex ratio, and furthermore, in contrast to the prediction that biases should be relative to the mean investment of the population, that milk provisioning biases might not be relative.Communicated by F. Trillmich     

The effect of ambient temperature on forager sound production and thoracic temperature in the stingless bee, <Emphasis Type="Italic">Melipona panamica</Emphasis>

Foragers of the stingless bees genus Melipona may produce intranidal sounds that are correlated with food location and quality. In this study, we provide the first detailed analysis of pulsed sounds produced by Melipona panamica foragers while feeding on a carbohydrate food source. We trained foragers to a 2.5-M sucrose feeder under normal, ambient temperature (23–33°C) and lower temperature (11–25°C) conditions. We recorded forager sounds under both conditions and tested the effect of temperature of the thorax, feeder plate, and air on sound temporal characteristics. Forager energetic expenditure and the number of pulses per visit were significantly higher in the cold condition than in the normal condition. Foragers spent a longer time at the feeder under the cold condition than during the normal condition. Interpulse durations were significantly shorter in the cold condition than in the normal condition and became progressively and significantly shorter at the end of each performance. Thus, pulse production increased before departure. Foragers increased their thoracic temperatures above ambient at all experimental air temperatures. Under chilled conditions, foragers had a significantly greater difference between thorax temperature and ambient air temperature than under normal conditions. Foragers must achieve a minimum flight muscle temperature before take-off, and thus forager sounds may be linked to muscle warm-up.     

浅谈人的不安全行为与安全生产

从行为学、安全系统工程学、心理学的观点,阐述了事故的致因。其中,人的不安全行为是事故发生的主要原因。因此,只有控制人的不安全行为,才能有效地避免人身事故的发生。     

制糖工业废水CODcr和BOD_5相关性探讨

在制糖工业废水的监测中 ,CODcr和BOD5均与水体的有机物有密切联系 ,且它们之间还存在一定的比例关系。通过对多组数据的相关性分析 ,确定以甘蔗为原料的制糖废水 ,CODcr和BOD5之间存在一定的相关性 ,可以通过CODcr值估算BOD5的值     

应用工业生态学解决污染与发展问题

面对日益尖锐的污染与发展之间的矛盾，在清洁生产基础上兴起的工业生态学是一门新的边缘学科，其概念和原理来源于生物生态学。讲述了工业生态学的概念、核心要旨和研究方法。对其在工业体系中的应用进行了初步的探讨，并提出了一些新的思路。     

Repeated hydrogen peroxide dosing briefly reduces cyanobacterial blooms and microcystin while increasing fecal bacteria indicators in a eutrophic pond

This study explored the effects of H₂O₂ on Cyanobacteria and non-target microbes using fluorometry, microscopy, flow cytometry, and high throughput DNA sequencing of the 16S rRNA gene during a series of mesocosm and whole-ecosystem experiments in a eutrophic pond in NY, USA. The addition of H₂O₂ (8 mg/L) significantly reduced Cyanobacteria concentrations during a majority of experiments (66%; 6 of 9) and significantly increased eukaryotic green and unicellular brown algae in 78% and 45% of experiments, respectively. While heterotrophic bacteria declined significantly following H₂O₂ addition in all experiments, bacteria indicative of potential fecal contamination (Escherichia coli, Enterococcus, fecal coliform bacteria) consistently and significantly increased in response to H₂O₂, evidencing a form of ‘pollution swapping’. H₂O₂ more effectively reduced Cyanobacteria in enclosed mesocosms compared to whole-ecosystem applications. Ten whole-pond H₂O₂ applications over a two-year period temporarily reduced cyanobacterial levels but never reduced concentrations below bloom thresholds and populations always rebounded in two weeks or less. The bacterial phyla of Cyanobacteria, Actinobacteria, and Planctomycetes were the most negatively impacted by H₂O₂. Microcystis was always reduced by H₂O₂, as was the toxin microcystin, but Microcystis remained dominant even after repeated H₂O₂ treatments. Although H₂O₂ favored the growth of eukaryotic algae over potentially harmful Cyanobacteria, the inability of H₂O₂ to end cyanobacterial blooms in this eutrophic waterbody suggests it is a non-ideal mitigation approach in high biomass ecosystems and should be used judiciously due to potential negative impacts on non-target organisms and promotion of bacteria indicative of fecal contamination.     

气浮-生化处理-砂滤工艺处理高浓度食品生产废水

食品生产废水属于高浓度有机废水,具有排水量大、污染物浓度、水质水量变化大的特点,如不处理就直接排放,将会对水环境造成严重的污染.本工程中废水原水水质参数为:CODCr＜5000mg/L,BOD5＜3000mg/L,SS＜500mg/L,pH5.0～7.5,水温20～30℃.针对该废水水质特点,采用气浮-生化-砂滤工艺处理食品生产废水.运行结果表明,该处理工艺具有处理效率高、操作管理简便、抗冲击负荷、污泥量小、出水水质稳定、运行成本低等优点,处理后出水CODCr85mg/L,BOD524.3mg/L,SS56.2mg/L,pH6～8,达到<污水综合排放标准>(GB8978-1996)中的一级标准.     

现代卷烟行业清洁生产审核

现代卷烟行业工艺技术成熟、自动化水平高,形成了产污较少、能耗高的行业特点。在对某卷烟厂进行的清洁生产审核中,针对行业特点,结合企业自身情况,提出并实施无、低费方案11项,中、高费方案6项。改善了车间环境,每年可节水约6万t,节电约20万kW·h,节约蒸汽约400t,减少废水排放约8万m3,节约资金514余万元,取得了良好的效益。     

量化风险评估(QRA)在海上生产设施风险管理中的应用

本文结合在胜利海区实施的量化风险评估工作，对量化风险评估在海上风险管理中的应用作一个简单的介绍。     

略谈清洁生产战略在医院废物处理中的指导意义

清洁生产战略作为环境管理的一项手段 ,是实现可持续发展战略的一项重要举措。医院废物作为一种危险废物 ,在其处理处置过程中 ,也应引入清洁生产思想 ,这对于有效利用资源和能源 ,减轻环境压力 ,都具有重要意义。