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991.
Hydrochemical, multivariate statistical, and inverse geochemical modeling techniques were used to investigate the hydrochemical
evolution within the Ain Azel aquifer, Algeria. Cluster analysis based on major ion contents defined 3 main chemical water
types, reflecting different hydrochemical processes. The first group water, group 1, has low salinity (mean EC = 735 μS/cm).
The second group waters are classified as Cl–HCO3-alkaline earth type. The third group is made up of water samples, the cation composition of which is dominated by Ca and
Mg with anion composition varying from dominantly Cl to dominantly HCO3 plus SO4. The varifactors obtained from R-mode FA indicate that the parameters responsible for groundwater quality variations are
mainly related to the presence and dissolution of some carbonate, silicate, and evaporite minerals in the aquifer. Inverse
geochemical modeling along groundwater flow paths indicates the dominant processes are the consumption of CO2, the dissolution of dolomite, gypsum, and halite, along with the precipitation of calcite, Ca-montmorillonite, illite, kaolinite,
and quartz. 相似文献
992.
Patinha C Reis AP Dias C Cachada A Adão R Martins H Ferreira da Silva E Sousa AJ 《Environmental geochemistry and health》2012,34(2):213-227
Previous environmental biomonitoring studies indicated higher environmental lead (Pb) pollution levels at the districts of
Aveiro and Leiria (Portugal). In evaluating the risk for human health, which is associated with contaminated soils after oral
uptake, total soil concentrations have generally been held against criteria established from toxicological studies based upon
the assumption that the uptake of the contaminant is similar in the toxicological studies and from the soils assessed. This
assumption is not always valid, as most toxicological studies are carried out with soluble forms of the contaminants, whereas
many soil contaminants are or become embedded in the soil matrix and thus exhibit limited availability. This study intends
to estimate the soluble fraction of Pb in the soils from central Portugal, and to assess the bioaccessibility of Pb and, hence,
infer exposure and risk for human health. Yet, as the physical–chemical properties of the soil exert some control over the
solubility of Pb in the surface environment, the relation between such soil properties and the estimated soluble and/or bioaccessible
fractions of Pb is also investigated. Other objective, with a more practical nature, was to give some contribution to find
a suitable in vitro mimetic of the gastrointestinal tract environment. The results indicate relatively low total metal concentrations
in the soils, even if differences between regions were observed. The Aveiro district has the higher total Pb concentration
and the metal is in more soluble forms, that is, geoavailable. Soils with higher concentrations of soluble Pb show higher
estimates of bioaccessible Pb. Soil pH seems to influence human bioaccessibility of Pb. 相似文献
993.
John?M.?Townsend-MehlerEmail author Fred?C.?Dyer 《Behavioral ecology and sociobiology》2012,66(2):275-286
While there has been considerable research on the behavioral processes that underlie animals’ ability respond to shifting
rewards, it remains unclear how animals coordinate multiple processes over time. To investigate this, we compared the behavior
of honeybees (Apis mellifera) and bumblebees (Bombus impatiens), in an open-ended search task. Bees were given brief access to a high-quality food source, which then became non-rewarding.
Then, over an extended period, we examined (1) bees’ tendency to persist at the depleted site, (2) their tendency to return
to a different low-quality food source where they had been foraging previously, (3) their tendency to return to the hive,
and (4) how previous reward history influenced their tendency to shift among these options. Compared to bumblebees, honeybees
were much slower to abandon the depleted site and were much more likely to make trips to the hive while bumblebees were much
more likely to return to the familiar low-quality site. These observed species differences are interpreted in terms of evolved
individual and social differences between these species. We show evidence of well-studied behavioral processes such as extinction,
negative contrast effects, and reliance on a social group, and provide, for the first time, a picture of how these processes
interact with one another as part of a common sequential decision-making process. 相似文献
994.
Matteo?Pizzolon Lisa?Locatello Robert?R.?Warner Nicole?Chimento Livio?Finos Maria?B.?RasottoEmail author 《Behavioral ecology and sociobiology》2012,66(3):497-504
Recent theoretical models predict that the relative allocation to advertisement and parental care depends on whether paternal
care is necessary for offspring survival: In species with exclusive male care, male investment in attraction is expected to
reliably indicate paternal care effort and male phenotypic quality. Previous research, yielding contrasting results, has considered
how one trait involved in mate attraction interacts with parental care or a specific aspect of male quality. In the blenny
Salaria pavo, we perform a comprehensive analysis of the interplay between overall male attractiveness and male quality, the latter in
terms of fertility, condition, and parental care. In this fish, males are larger than females, exhibit two sexually dimorphic
traits (head crest and anal glands), and solely care for eggs. We generated a male attractiveness index through principal
component analyses of morphological traits and quantified parental effort as the total time spent in egg care. In addition,
we analyzed the relationships between specific components of attractiveness and male qualities. In agreement with theory predictions,
we found that male overall attractiveness is a reliable indicator of fertility, in terms of sperm number, but is unrelated
to body condition and parental care effort, with males able to perform high levels of care regardless of their level of advertisement.
However, the relative expression of head crest area appears positively related to sperm number but is traded-off with parental
care effort. These findings underline the need, in addressing real patterns, to consider interactions between multiple aspects
of male display and quality. 相似文献
995.
An animal’s use of space may be strongly influenced by habitat edges and neighboring conspecifics encountered in and around
its home range. Habitat edges are known to affect species density and distribution, but their impact on home range use is
largely unknown. Additionally, among large animals, interactions with neighbors become particularly important as increasing
home range size leads to decreasing exclusivity of resource use, but the effect of neighbors on home range use remains poorly
understood. Here, we examine the influence of neighbors and habitat edges on the ranging patterns of three groups of Phayre’s
leaf monkeys (Trachypithecus phayrei crepusculus) in northeast Thailand over a period of more than 2 years. The study animals occupied dry evergreen forest, and adjacent
patches of dry dipterocarp forest created a habitat edge and formed barriers between some groups. We found that the use of
home range interiors was 50–90% higher than the border areas, indicating concentrated use of resources within the home range.
The use of peripheral areas was influenced by social organization, the presence of neighboring groups, and forest edges. While
one multimale group showed no particular habitat preference, two single-male groups preferred areas bordering dry dipterocarp
habitat and avoided areas bordering neighboring groups, suggesting that the threat of neighbors mediated border presence.
Additionally, groups may have been attracted to the forest edge, where conspecific competitors are absent and increased sunlight
may increase resource abundance and/or quality. This study revealed that the use of border areas can be modulated by neighboring
groups and habitat edges, thereby adding to our understanding of home range use among territorial species in heterogeneous
habitats. 相似文献
996.
Ivonne?MeucheEmail author K.?Eduard?Linsenmair Heike?Pr?hl 《Behavioral ecology and sociobiology》2012,66(4):613-621
In many species male reproductive success is limited by access to females. Territoriality is one behavioural strategy which
helps to acquire females. In the present study, we investigated the correlation between territory size and (1) female availability
and (2) rate of intrusion by conspecific males in strawberry poison frogs, Oophaga pumilio. Males defended smaller territories in areas with a high female density and high rate of intrusion by conspecific males.
Only males with high body condition values were able to establish territories in areas of high female density probably due
to better fighting abilities. Moreover, dominant calling frequency was lower during agonistic interactions. Because only males
with high body condition values were able to produce very low dominant frequencies, the acoustic properties appear to be an
honest signal containing information about fighting abilities. Thus, the negative correlation between dominant frequency and
mating success of males found in previous studies seems to be in part the result of intrasexual competition between males. 相似文献
997.
Meeghan?E.?GrayEmail author Elissa?Z.?Cameron Mary?M.?Peacock David?S.?Thain Veronica?S.?Kirchoff 《Behavioral ecology and sociobiology》2012,66(4):529-537
A growing number of studies conducted on diverse taxa have shown that extra-pair/group paternity is higher than what would
be predicted from behavioral observations alone. While it may be beneficial for females to mate with multiple males, this
often results in offspring not sired by the behavioral father, which could influence offspring survival, especially in social
mammals. Feral horses (Equus caballus) maintain stable social relationships over several years, usually with one stallion defending a harem band of unrelated mares
against other males. Sneak copulations by subordinate males have been observed and mares sometimes change bands, both of which
can result in foals sired by males other than the dominant band stallion. We measured female fidelity in free-ranging feral
horses in 23 bands, with 51 foals over four foaling seasons and tested offspring paternity against parental behaviors. We
used 12 polymorphic microsatellite loci and the program CERVUS 2.0 to determine and exclude potential sires. The majority
of mares remained in the band with the sire of their foal resulting in most foals being sired by the band stallion. Most foals
that were not sired by the band stallion were born in the year after a round-up and we could not determine if they were the
result of band changing or sneak copulations. Foals born into a band without their sire had lower survival rates and mothers
were significantly more protective of foals not sired by the band stallion. These findings suggest that band stability increases
the reproductive success of mares and support the importance of infanticide risk in equid social structure. 相似文献
998.
Šmuc NR Dolenec T Serafimovski T Tasev G Dolenec M Vrhovnik P 《Environmental geochemistry and health》2012,34(4):513-526
Heavy metal contamination of soils is widespread and induces a long-term risk to ecosystem health. This research focuses on the heavy metal contamination, transfer values and risk assessment in the Ko?ani Field plant system (Republic of Macedonia). To identify the heavy metal concentrations in Ko?ani crops (rice and maize), the geochemical analysis was performed by inductive coupled plasma mass spectrometer and thereupon the transfer factor (TF) and estimated daily intake amount values were calculated. The highest As, Cd, Mo, Pb and Zn values were determined in the rice samples grown in the paddy fields near the Zletovska River. The highest Pb and Mo concentrations measured in the maize samples were from the maize fields near the Zletovska River and Ciflik city. High TF values for Mo, Zn, Cd and Cu revealed a strong accumulation of Mo, Zn and Cd by rice and Mo and Zn by maize crops. The results of the estimated daily intake showed that the regular consumption of rice and maize crops containing the highest Cd, Mo, Pb and Zn concentrations could pose a serious threat to human health, because the daily intake of Cd, Mo, Pb and Zn for crops grown in the fields around the Zletovska River exceeded the recommended provisional tolerable daily intake values. Taking into account the results, the area around Zletovska River is considered as the most anthropogenically impacted part of Ko?ani Field. 相似文献
999.
A theoretical model, based on linear stability analysis, is proposed to predict the onset of natural convection in lakes and
reservoirs due to night time cooling. To such purpose, the system was modelled as a initially quiescent deep Boussinesq fluid
reservoir, whose upper boundary temperature changes sinusoidally. From scaling analysis, it is found that critical onset times
for convection are proportional to R
−2/7, where R is a Rayleigh number including fluid properties and forcing frequency. The proportionality constant was found, from the solution
of an eigenvalue problem, as a function of the Prandtl number. The onset time for convection was easily observed from experiments
and quantitatively detected as a rapid increase of the RMS of the computed velocity field obtained using PIV. In this controlled
conditions, differences close to 10% between predicted and observed times for the start of the convective flow was found.
It is apparent from the present set of results that predictions are reasonable. 相似文献
1000.
Diogo Rúben Neves Sara Rodrigues Concei??o Juana Fortes Maria Teresa Reis Jo?o Alfredo Santos Rui Capit?o 《Journal of Coastal Conservation》2012,16(4):489-501
This paper describes a first approach on the risk assessment in port navigation using GUIOMAR, an integrated system for port and coastal engineering modelling developed at the National Civil Engineering Laboratory (LNEC), Portugal, using a GIS software environment. A set of automatic procedures was designed to include a new methodology based on the amplitude of the wave-induced vertical movement of a ship along its trajectory. In this methodology, the risk in port navigation is assessed on the basis of a combination of the probability of exceedance of a pre-set threshold for the ship??s vertical movements and its consequences. To test the new procedures, a set of sea wave records obtained at the Sines wave-buoy from 1988 to 2002 was transferred into Sines Port using two numerical models of sea wave propagation and deformation (SWAN and DREAMS), included in the GUIOMAR system. The numerical model WAMIT was used for estimating the wave-induced ship??s vertical movements inside the port. By applying the new procedures, automatic generation of risk maps was carried out for navigation in the vicinity of the West breakwater of the Port of Sines. The recent developments contribute towards a more versatile and efficient GUIOMAR system, which results in a more adequate tool to support decision-making processes in port and coastal management. 相似文献