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201.
Summary The suckling behaviour of 130 freeranging elephant calves aged between birth and 4.5 years old was examined in Amboseli National Park, Kenya. Analyses of frequencies of suckling and durations of suckling bouts showed that males attempted to suckle more often, were more successful at their attempts, and as a result were estimated to have a higher milk intake than did female calves. Mothers were equally tolerant of their sons' and daughters' demands to suckle at young ages, but were less tolerant of their older sons' demands. The growth rates of males based on hind footprint length were faster than those of females from birth onwards. During drought years with low food availability, male calf survivorship in the first year was lower than that of female calves. During wet years, there was little difference between sexes in survivorship. It appeared that during dry years mothers were unable to sustain milk production at a level that met the metabolic requirements of their sons, and as result male calves were more likely to die. Females with a surviving son tended to have a longer interbirth interval than did females with a surviving daughter. We suggest that greater early maternal investment in male calves occurs because, in the highly-competitive polygynous mating system of elephants, size in adult male elephants is an important factor in mating success. 相似文献
202.
We seek to bridge the macro concept of corporate social responsibility (CSR) with micro research in organizational justice. A theoretical model is presented whereby employees' perceptions of CSR impact their subsequent emotions, attitudes, and behaviors, mediated by instrumental, relational, and deontic motives/needs, as well as moderated by organizations' social accounts. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
203.
Zuo Tong How Ina Kristian Francesco Busetti Kathryn L. Linge Cynthia A. Joll 《环境科学学报(英文版)》2017,29(8):2-18
This paper is a critical review of current knowledge of organic chloramines in water systems,including their formation, stability, toxicity, analyticalmethods for detection, and their impact
on drinking water treatment and quality. The term organic chloramines may refer to any
halogenated organic compounds measured as part of combined chlorine (the difference
between themeasured free and total chlorine concentrations), andmay include N-chloramines,
N-chloramino acids, N-chloraldimines and N-chloramides. Organic chloramines can form
when dissolved organic nitrogen or dissolved organic carbon react with either free chlorine
or inorganic chloramines. They are potentially harmful to humans and may exist as an
intermediate for other disinfection by-products. However, little information is available on the
formation or occurrence of organic chloramines in water due to a number of challenges. One of
the biggest challenges for the identification and quantification of organic chloramines in water
systems is the lack of appropriate analytical methods. In addition, many of the organic
chloramines that formduring disinfection are unstable,which results in difficulties in sampling
and detection. To date research has focussed on the study of organic monochloramines.
However, given that breakpoint chlorination is commonly undertaken in water treatment
systems, the formation of organic dichloramines should also be considered. Organic
chloramines can be formed frommany different precursors and pathways. Therefore, studying
the occurrence of their precursors in water systems would enable better prediction and
management of their formation. 相似文献
204.
Ryan M. Maher Heidi Asbjornsen Randall K. Kolka Cynthia A. Cambardella James W. Raich 《Agriculture, ecosystems & environment》2010,139(4):749-753
Close relationships among climatic factors and soil respiration (Rs) are commonly reported. However, variation in Rs across the landscape is compounded by site-specific differences that impede the development of spatially explicit models. Among factors that influence Rs, the effect of ecosystem age is poorly documented. We hypothesized that Rs increases with grassland age and tested this hypothesis in a chronosequence of tallgrass prairie reconstructions in central Iowa, U.S.A. We also assessed changes in root biomass, root ingrowth, aboveground net primary productivity (ANPP), and the strength of soil temperature and moisture in predicting Rs. We found a significant increase in total growing season Rs with prairie age (R2 = 0.79), ranging from 714 g C m?2 in the youngest reconstruction (age 4) to 939 g C m?2 in the oldest prairie (age 12). Soil temperature was a strong predictor of intra-seasonal Rs among prairies (R2 = 0.78–0.87) but mean growing season soil temperature and moisture did not relate to total Rs. The increase in Rs with age was positively correlated with root biomass (r = 0.80) and ANPP (r = 0.87) but not with root ingrowth. Our findings suggest that growing season Rs increases with tallgrass prairie age, root biomass, and ANPP during young grassland development. 相似文献
205.
Lori H. Schwacke Tiago A. Marques Len Thomas Cormac G. Booth Brian C. Balmer Ashley Barratclough Kathleen Colegrove Sylvain De Guise Lance P. Garrison Forrest M. Gomez Jeanine S. Morey Keith D. Mullin Brian M. Quigley Patricia E. Rosel Teresa K. Rowles Ryan Takeshita Forrest I. Townsend Todd R. Speakman Randall S. Wells Eric S. Zolman Cynthia R. Smith 《Conservation biology》2022,36(4):e13878
The 2010 Deepwater Horizon (DWH) oil spill exposed common bottlenose dolphins (Tursiops truncatus) in Barataria Bay, Louisiana to heavy oiling that caused increased mortality and chronic disease and impaired reproduction in surviving dolphins. We conducted photographic surveys and veterinary assessments in the decade following the spill. We assigned a prognostic score (good, fair, guarded, poor, or grave) for each dolphin to provide a single integrated indicator of overall health, and we examined temporal trends in prognostic scores. We used expert elicitation to quantify the implications of trends for the proportion of the dolphins that would recover within their lifetime. We integrated expert elicitation, along with other new information, in a population dynamics model to predict the effects of observed health trends on demography. We compared the resulting population trajectory with that predicted under baseline (no spill) conditions. Disease conditions persisted and have recently worsened in dolphins that were presumably exposed to DWH oil: 78% of those assessed in 2018 had a guarded, poor, or grave prognosis. Dolphins born after the spill were in better health. We estimated that the population declined by 45% (95% CI 14–74) relative to baseline and will take 35 years (95% CI 18–67) to recover to 95% of baseline numbers. The sum of annual differences between baseline and injured population sizes (i.e., the lost cetacean years) was 30,993 (95% CI 6607–94,148). The population is currently at a minimum point in its recovery trajectory and is vulnerable to emerging threats, including planned ecosystem restoration efforts that are likely to be detrimental to the dolphins’ survival. Our modeling framework demonstrates an approach for integrating different sources and types of data, highlights the utility of expert elicitation for indeterminable input parameters, and emphasizes the importance of considering and monitoring long-term health of long-lived species subject to environmental disasters. Article impact statement: Oil spills can have long-term consequences for the health of long-lived species; thus, effective restoration and monitoring are needed. 相似文献
206.
Daniel-Mkpume Cynthia Chikodi Ahaiwe Rachel Chinwendu Ifenatuorah Chigozie Lucas Ike-Eze Ikechukwu Christian Ezema Aigbodion Victor Sunday Egoigwe Sochima Vincent Okonkwo Emenike George 《Journal of Material Cycles and Waste Management》2022,24(2):680-691
Journal of Material Cycles and Waste Management - This study contributes towards showing the potential end-of-life application of common wastes namely: Waste Toner powder (WTP) and African star... 相似文献
207.
Lozano Lazo Denise P. Bojanic Helbingen Cynthia Gasparatos Alexandros 《Journal of Material Cycles and Waste Management》2023,25(1):565-581
Journal of Material Cycles and Waste Management - Detailed information about waste generation rates, composition, and their influencing factors, is essential for sustainable municipal solid waste... 相似文献