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941.
Do penguins dare to walk at night? Visual cues influence king penguin colony arrivals and departures
Anna P. Nesterova Céline Le Bohec David Beaune Emeline Pettex Yvon Le Maho Francesco Bonadonna 《Behavioral ecology and sociobiology》2010,64(7):1145-1156
Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the presence of many individuals.
We studied king penguins (Aptenodytes patagonicus) that live in dense colonies and are constantly faced with such problems. Our aims were to describe adult penguin homing
paths on land and to test whether visual cues are important for their orientation in the colony. We also tested the hypothesis
that older penguins should be better able to cope with limited visual cues due to their greater experience. We collected and
examined GPS paths of homing penguins. In addition, we analyzed 8 months of penguin arrivals to and departures from the colony
using data from an automatic identification system. We found that birds rearing chicks did not minimize their traveling time
on land and did not proceed to their young (located in crèches) along straight paths. Moreover, breeding birds' arrivals and
departures were affected by the time of day and luminosity levels. Our data suggest that king penguins prefer to move in and
out of the colony when visual cues are available. Still, they are capable of navigating even in complete darkness, and this
ability seems to develop over the years, with older breeding birds more likely to move through the colony at nighttime luminosity
levels. This study is the first step in unveiling the mysteries of king penguin orientation on land. 相似文献
942.
沉水植物伊乐藻光合放氧对水体氮转化的影响 总被引:1,自引:0,他引:1
实验室内利用聚乙烯容器于光照培养箱内开展开放和封闭实验,研究沉水植物伊乐藻(Elodea nuttallii)光合放氧对水体氮转化的影响及其对水体氮的净化效果和机理。结果表明,伊乐藻光合放氧使水体DO和pH值升高,促进了开放系统氨氮的挥发,同时水体较低的氨氮含量及较高的pH值抑制了氨氮向硝氮的转化。封闭系统通过阻止氨氮的挥发降低了总氮的去除作用,但并不影响氨氮向硝氮的转化。另外,高的DO和pH环境不利于反硝化细菌的存活,使反硝化作用比较微弱或不存在。 相似文献
943.
This study evaluated pilot‐scale active caps composed of apatite, organoclay, biopolymers, and sand for the remediation of metal‐contaminated sediments. The active caps were constructed in Steel Creek, at the Savannah River Site near Aiken, South Carolina. Monitoring was conducted for 12 months. Effectiveness of the caps was based on an evaluation of contaminant bioavailability, resistance to erosion, and impacts on benthic organisms. Active caps lowered metal bioavailability in the sediment during the one‐year test period. Biopolymers reduced sediment suspension during cap construction, increased the pool of carbon, and lowered the release of metals. This field validation showed that active caps can effectively treat contaminants by changing their speciation, and that caps can be constructed to include more than one type of amendment to achieve multiple goals. © 2012 Wiley Periodicals, Inc. 相似文献
944.
Kenneth M. Doll Erin L. Walter Rex E. Murray Hong-Sik Hwang 《Journal of Polymers and the Environment》2018,26(9):3670-3676
Organogels are used in a variety of high value applications including the removal of toxic solvents from aqueous environments and the time-controlled release of compounds. One of the most promising gelators is a polyvinyl polymer containing medium chain length carboxylic acids. The existing production of this product requires synthesis of vinyl esters containing medium length carboxylic chains. This starting material must be made from an expensive and low yielding transvinylation reaction, which leaves production of useful vinyl esters and, as a result, the organogels themselves, outside the realm of practical chemistry. We have developed a new, more practical production process and used it to directly synthesize a new polymer. This new process utilizes commercially available polyvinyl acetate and accomplishes the transformation with simple hydrolysis and anhydride addition steps. The new polymers form organogels with chloroform, acetone or toluene with swell ratios up to 30. They also show time-controlled release of crystal violet over a 100 h span. This new production process opens the possibility of producing organogels utilizing agricultural resources. 相似文献
945.
Carstensen Jacob Conley Daniel J. Almroth-Rosell Elin Asmala Eero Bonsdorff Erik Fleming-Lehtinen Vivi Gustafsson Bo G. Gustafsson Camilla Heiskanen Anna-Stiina Janas Urzsula Norkko Alf Slomp Caroline Villnäs Anna Voss Maren Zilius Mindaugas 《Ambio》2020,49(6):1194-1210
Ambio - The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different... 相似文献
946.
947.
Jana Kopčeková Anna Kolesárová Anton Kováčik Eva Kováčiková Martina Gažarová Peter Chlebo 《Journal of environmental science and health. Part. B》2018,53(5):298-303
The present study was designed to reveal whether long-term consumption of bitter apricot seeds causes changes in lipid profile and other risk factors for cardiovascular diseases. The study group consisted of 12 healthy adult volunteers (5 females and 7 males). The average age of women was 41.60 ± 11.28 years and the average age of men was 36.71 ± 13.70 years. Volunteers consumed 60 mg kg?1 of body weight of bitter apricot seeds divided into 8–12 doses daily for 12 weeks. Volunteers were recruited from the general population of Slovak Republic. After 12 weeks, mean body weight of the participants increased from 77.34 to 78.22 kg (P > 0.05). The average total cholesterol levels decreased from 4.86 mmol L?1 at the beginning of the study to 4.44 mmol L?1 at the end of the study (P < 0.05). We did not observe any significant increase in high-density cholesterol (from 1.55 to 1.60 mmol L?1). The average low-density cholesterol levels decreased from 2.93 mmol L?1 at the beginning of the study to 2.31 mmol L?1 at the end of the study (P < 0.001). Concentration of triglycerides increased significantly over the 12-week intervention period from 0.84 to 1.17 mmol L?1. After the intervention, the high-sensitivity C-reactive protein level decreased from 1.92 to 1.23 mg L?1, but results were non-significant (P > 0.05). Creatine kinase serum levels increased from 2.31 to 2.77 mg L?1 (P > 0.05) over the 12-week intervention period. The results suggest that regular intake of bitter apricot seeds may be considered potentially useful for prevention of cardiovascular diseases. 相似文献
948.
Giovanna Moura Calazans Carolina Cristiane Pinto Elizângela Pinheiro da Costa Anna Flávia Perini Sílvia Corrêa Oliveira 《Environmental monitoring and assessment》2018,190(8):491
This study sought to evaluate and propose adjustments to the water quality monitoring network of surface freshwaters in the Paraopeba river basin (Minas Gerais, Brazil), using multivariate statistical methods. A total of 13,560 valid data were analyzed for 19 water quality parameters at 30 monitoring sites, over a period of 5 years (2008–2013). The cluster analysis grouped the monitoring sites in eight groups based on similarities of water quality characteristics. This analysis made it possible to detect the most relevant monitoring stations in the river basin. The principal components analysis associated with non-parametric tests and the analysis of violation of the standards prescribed by law, allowed for identifying the most relevant parameters which must be maintained in the network (thermotolerant coliforms, total manganese, and total phosphorus). The discharge of domestic sewage and industrial wastewater, that from mining activities and diffuse pollution from agriculture and pasture areas are the main sources of pollution responsible for the surface water quality deterioration in this basin. The BP073 monitoring site presents the most degraded water quality in the Paropeba river basin. The monitoring sites BP094 and BP092 are located geographically close and they measure similar water quality, so a possible assessment of the need to maintain only one of the two in the monitoring network is suggested. Therefore, multivariate analyses were efficient to assess the adequacy of the water quality monitoring network of the Paraopeba river basin, and it can be used in other watersheds. 相似文献
949.
Evangelos Karanasios Helen Karasali Anna Marousopoulou Antigoni Akrivou Emilia Markellou 《Environmental monitoring and assessment》2018,190(6):361
The persistence of glyphosate and its primary metabolite AMPA (aminomethylphosphonic acid) was monitored in two areas in Southern Greece (Peza, Crete and Chora Trifilias, Peloponnese) with a known history of glyphosate use, and the levels of residues were linked to spray operators’ activities in the respective areas. A total of 170 samples were collected and analysed from both areas during a 3-year monitoring study. A new method (Impact Assessment Procedure - IAP) designed to assess potential impacts to the environment caused by growers’ activities, was utilised in the explanation of the results. The level of residues was compared to the predicted environmental concentrations in soil. The ratio of the measured concentrations to the predicted environmental concentrations (MCs/PECs) was >?1 in Chora the first 2 years of sampling and <?1 in the third year, whilst the MCs/PECs ratio was <?1 in Peza, throughout the whole monitoring period. The compliance to the instructions for best handling practices, which operators received during the monitoring period, was reflected in the amount of residues and the MCs/PECs ratio in the second and especially the third sampling year. Differences in the level of residues between areas as well as sampling sites of the same area were identified. AMPA persisted longer than the parent compound glyphosate in both areas. 相似文献
950.
Giovanna Moura Calazans Carolina Cristiane Pinto Elizângela Pinheiro da Costa Anna Flávia Perini Sílvia Corrêa Oliveira 《Environmental monitoring and assessment》2018,190(12):726
Surface water quality monitoring networks are usually deployed and rarely re-evaluated with regard to their effectiveness. In this sense, this work sought to evaluate and to guide optimization projects for the water quality monitoring network of the Velhas river basin, using multivariate statistical methods. The cluster, principal components, and factorial analyses, associated with non-parametric tests and the analysis of violation to the standards set recommended by legislation, identified the most relevant water quality parameters and monitoring sites, and evaluated the sampling frequency. Thermotolerant coliforms, total arsenic, and total phosphorus were considered the most relevant parameters for characterization of water quality in the river basin. The monitoring sites BV156, BV141, BV142, BV150, BV137, and BV153 were considered priorities for maintenance of the network. The multivariate statistical analysis showed the importance of a monthly sampling frequency, specifically the parameters considered most important. 相似文献