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11.
Fabio Ricci Roberto Cenciarini Alessandro Lorenzi Giorgio Famiglini Elisabetta Pierini Achille Cappiello 《Chemistry and Ecology》2016,32(1):88-102
The aim of this study was to monitor for the first time the oligosaccharide pattern in the northwestern Adriatic Sea. Oligosaccharides are components of the low-molecular-weight fraction of dissolved organic matter (DOM). They perform an important ecological function in the microbial loop prompting substrates for bacterial degradation. In particular, our investigation focused on maltooligosaccharides (glucose α 1–4 linked). The analyses were carried out using a dialysis-charcoal column sorption pre-concentration method, followed by liquid chromatography-tandem mass spectrometry analyses with a triple quadrupole mass spectrometer operating in multiple reaction monitoring mode. During the study period, the concentration of maltooligosaccharides with a low degree of polymerisation (ranging from maltose to maltotetraose) was higher than other maltooligosaccharides (maltopentaose and maltoeptaose) and all together they reached their highest concentration in June. This concentration was temporally shifted from a long period of diatom bloom (from January to April). Furthermore, the annual maltooligosaccharide trend was monitored together with several chemical, physical and biological parameters to investigate their potential role on the maltooligosaccharide accumulation. Our results suggested that the maltooligosaccharide accumulation could be related to the water column stratification. 相似文献
12.
Polycyclic aromatic hydrocarbon (PAH) concentrations were determined in 16 topsoils (0–10 cm) collected across the site of
a former tar works in NE England. The soils were prepared in the laboratory to two different particle size fractions: <250 μm
(fraction A) and >250 μm to <2 mm (fraction B). Sixteen priority PAHs were analysed in the soils using in situ pressurised
fluid extraction (PFE) followed by gas chromatography—mass spectrometry (GC–MS). The average total PAH concentration in the
soils ranged from 9.0 to 1,404 mg/kg (soil fraction A) and from 6.6 to 872 mg/kg (soil fraction B). These concentrations are
high compared with other industrially contaminated soils reported in the international literature, indicating that the tar
works warrants further investigation/remediation. A predominance of higher-molecular-weight compounds was determined in the
samples, suggesting that the PAHs were of pyrogenic (anthropogenic) origin. Statistical comparison (t-test) of the mean total PAH concentrations in soil fractions A and B indicated that there was a significant difference (95%
confidence interval) between the fractions in all but two of the soil samples. Additionally, comparisons of the distributions
of individual PAHs (i.e. 16 PAHs × 16 soil samples) in soil fractions A and B demonstrated generally higher PAH concentrations
in fraction A (i.e. 65.8% of all individual PAH concentrations were higher in soil fraction A). This is important because
fraction A corresponds to the particle size thought to be most important in terms of human contact with soils and potential
threats to human health. 相似文献
13.
Varenka Lorenzi Ryan L. Earley Matthew S. Grober 《Behavioral ecology and sociobiology》2006,59(6):715-722
Sex change in marine teleost fishes is commonly regulated by social factors. In species that exhibit protogynous sex change,
such as the bluebanded goby Lythrypnus dalli, the most dominant female typically initiates sex change when a male is removed from the social group. Females can use visual,
chemical or tactile cues to assess the presence or absence of a male. The primary goal of our study was to determine whether
the olfactory and visual presence of a male versus its behavioural interactions with females were important for mediating
sex change. We exposed females to three different treatments: absence of a male, presence of a male that could physically
interact with her and presence of a male behind a barrier that allowed visual and olfactory interactions but prohibited physical
interactions. Sex change occurred in the absence of a male but not in the presence of a male that could physically interact
with the female. The presence of a male behind the barrier did not prevent sex change but affected the timing of sex change.
Season appeared to affect the latency to initiate male typical courtship, with a delay at the end of the reproductive season
only when the male was present behind the barrier. We discuss the seasonal results in terms of L. dalli life history and the potential benefits and costs of changing sex late in the season in the presence or absence of aggressive
reinforcement by the male. Our results identify direct behavioural interactions as an important proximate mechanism in the
social regulation of sex change in L. dalli. 相似文献
14.
Alfieri S. M. Riccardi M. Menenti M. Basile A. Bonfante A. De Lorenzi F. 《Mitigation and Adaptation Strategies for Global Change》2019,24(3):435-466
Mitigation and Adaptation Strategies for Global Change - Adaptation to climate change is a major challenge facing the agricultural sector worldwide. Olive (Olea europaea L.) is a global,... 相似文献