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1.
Milan Vrtílek Jakub Žák Radim Blažek Matej Polačik Alessandro Cellerino Martin Reichard 《Die Naturwissenschaften》2018,105(11-12):68
Senescence in wild populations was long considered negligible but current evidence suggests that it is widespread in natural populations of mammals and birds, affecting the survival and reproductive output of older individuals. In contrast, little is known about reproductive senescence in species with asymptotic growth that can keep increasing their reproductive output as they grow older and larger. Using a cross-sectional study, we tested age-related decline in fecundity and relative allocation to reproduction in five wild populations of an annual killifish, Nothobranchius furzeri (Cyprinodontiformes). We did not detect any decline in absolute female egg production over their short lifespan in the wild. Relative fecundity (egg production controlled for female body mass) tended to decrease with age. This effect was driven primarily by a single population that survived 17 weeks, almost twice as long as the median persistence of the other four study populations. There was no decrease in relative ovary mass while in males, relative testes mass actually increased with age. Intra-population variation in relative ovary mass increased in older females suggesting heterogeneity in individual trajectories of female reproductive allocation. Overall, we demonstrate that annual killifish do not experience significant age-related decline in reproductive functions during their very short lifespan in the wild despite the marked deterioration of gonad tissue detected in captivity. 相似文献
2.
Christina G.L. Nerstad Rosalind Searle Matej Černe Anders Dysvik Miha Škerlavaj Ronny Scherer 《组织行为杂志》2018,39(4):429-447
Interpersonal trust is associated with a range of adaptive outcomes, including knowledge sharing. However, to date, our knowledge of antecedents and consequences of employees feeling trusted by supervisors in organizations remains limited. On the basis of a multisource, multiwave field study among 956 employees from 5 Norwegian organizations, we examined the predictive roles of perceived mastery climate and employee felt trust for employees' knowledge sharing. Drawing on the achievement goal theory, we develop and test a model to demonstrate that when employees perceive a mastery climate, they are more likely to feel trusted by their supervisors at both the individual and group levels. Moreover, the relationship between employees' perceptions of a mastery climate and supervisor‐rated knowledge sharing is mediated by perceptions of being trusted by the supervisor. Theoretical contributions and practical implications of our findings are discussed. 相似文献
3.
Matjaž Hriberšek Niko Samec Jure Ravnik Matej Zadravec 《Environmental Modeling and Assessment》2011,16(5):479-489
The contribution presents numerical simulation of gypsum particles, lifting from a gypsum landfill. First, particle characteristics
are presented, resulting from different technologies of gypsum depositing. Next, a laboratory experiment parameter validation
tests are described, which served as a means of determination of mass flow of particles from the landfill. The background
of the numerical simulations, used in the assessment of landfill impact on the environment, is also described. Simulations
consist of two parts: simulation of a long term impact of the particles on the surrounding area, performed by implementation
of the Gaussian dispersion model based computer code ISC3, and second, a CFD based simulation for assessing the flow and mass
concentration fields in the vicinity of the landfill for several pre-selected flow cases. The results of both computational
approaches are presented and compared. In the conclusions, a relation of the simulation results with existing environmental
pollution levels is made, and recommendations for landfill management are drawn. 相似文献
4.
Munteanu Catalina Kuemmerle Tobias Boltiziar Martin Lieskovský Juraj Mojses Matej Kaim Dominik Konkoly-Gyuró Éva Mackovčin Peter Műller Daniel Ostapowicz Katarzyna Radeloff Volker C. 《Regional Environmental Change》2017,17(8):2209-2222
Regional Environmental Change - Historical land use may shape landscapes for centuries into the future, but it remains unclear how much land-use legacies affect contemporary land use. Knowing for... 相似文献
5.
Rožič PŽ Dolenec T Baždarić B Karamarko V Kniewald G Dolenec M 《Environmental science and pollution research international》2011,19(7):2708-2721
Introduction and purpose
Studies examining the environmental impact of marine aquaculture have increased significantly in number during the last few decades. The present paper investigates a region of rapid growth in intensive aquaculture and its influence on the local marine ecosystem.Discussion
This study was undertaken with the specific aim of assessing the effect of fish farming on marine sediment at a farm near the island of Vrgada in the Central Adriatic. Data obtained regarding major (Si, Al, K, Na, Fe, Ca, Mg), minor (Mn, P, Ti) and trace (As, Au, Ba, Cd, Co, Cr, Cs, Cu, Ga, Hf, Hg, Mo, Nb, Ni, Pb, Rb, Sb, Sc, Se, Sr, Ta, Th, Tl, U, V, Y, Zn, Zr) elements were used to estimate the spatial and temporal distribution of metals in the sediment and their possible relationship with local aquacultural activity.Results
Although the measured concentrations of heavy metals in sediment below fish cages were notably different and potentially a result of farming activity, the values were generally lower than background concentrations observed in the Central Adriatic. In contrast, concentrations of heavy metals at a reference site unaffected by aquaculture varied from lower levels to values even higher than those observed below the high-production cages. Furthermore, calculated environmental index values indicate that the sediment below the farm is either uncontaminated or suffers from only low levels of contamination.Conclusion
Such results suggest that the effect of observed fish farm activity on the local marine ecosystem is practically negligible. 相似文献6.
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
7.
Petra Žvab Rožič Tadej Dolenec Branimir Baždarić Vatroslav Karamarko Goran Kniewald Matej Dolenec 《Environmental geochemistry and health》2014,36(1):19-39
In this study, the role of aquaculture activity as a source of selected metals was analyzed. Significant differences in element content between cultured (Dicentrarchus labrax, Sparus aurata) and wild fishes as well as between fish muscle and their feed were detected. Higher concentrations of trace elements (i.e., As, Cu, Hg, Se) in wild fish tissues in comparison with cultured ones indicate additional sources of metals beside fish feed as natural and/or anthropogenic sources. Generally, mean Cd, Cu, Pb, Se, and Zn concentrations in cultured (0.016, 1.79, 0.14, 0.87, and 34.32 μg/g, respectively) and wild (0.011, 1.97, 0.10, 1.78, and 23,54 μg/g, respectively) fish samples were below the permissible levels, while mean As (2.57 μg/g in cultured, 4.77 μg/g in wild) and Cr (5.25 μg/g in cultured, 2.92 μg/g in wild) values exceeded those limits. Hg values were lower in cultured (0.17 μg/g) and higher in wild (1.04 μg/g) fish specimens. The highest elemental concentrations were observed in almost all fish samples from Kor?ula sampling site. The smallest cultured sea basses showed As (4.01 μg/g), Cr (49.10 μg/g), Pb (0.65 μg/g), and Zn (136 μg/g) concentrations above the recommended limits; however, values decreased as fish size increased. Therefore, the majority of metal concentrations in commercial fishes showed no problems for human consumption. Also calculated Se:Hg molar ratios (all >1) and selenium health benefit values (Se-HBVs) (all positive) showed that consumption of all observed fishes in human nutrition is not risk. 相似文献
8.
Rogan N Serafimovski T Dolenec M Tasev G Dolenec T 《Environmental geochemistry and health》2009,31(4):439-451
This research focuses on the heavy metal contamination of the paddy soils and rice from Kočani Field (eastern Macedonia) resulting
from irrigation by riverine water impacted by past and present base-metal mining activities and acid mine drainage. Very high
concentrations of As, Cd, Cu, Pb and Zn were found in the paddy soils (47.6, 6.4, 99, 983 and 1,245 μg g−1) and the rice (0.53, 0.31, 5.8, 0.5 and 67 μg g−1) in the western part of Kočani Field, close to the Zletovska River, which drains the mining facilities of the Pb–Zn mine
in Zletovo. In terms of health risk, the observed highest concentrations of these elements in the rice could have an effect
on human health and should be the subject of further investigations. 相似文献
9.
Recent theoretical and empirical studies have shown that male dominance is often at odds with female mate preference and that
indirect (genetic) benefits of mate choice may not be related to male dominance. We tested whether female preference corresponded
to male dominance and whether mating with dominant males conveyed benefits to offspring fitness in a small freshwater fish,
the African annual killifish Nothobranchius korthausae (Cyprinodontiformes), a species without parental care. The experimental design used controlled for the effect of male age,
possibility of sperm and egg depletion, and accounted for a potential that females express their preference through maternal
effects by manipulation of egg mass during ovulation. By sequentially mating females with males of known dominance, we found
that female N. korthausae showed no mate preference in terms of egg numbers deposited with respect to male dominance or body size and no congruent
mate preference to specific males was detected. However, males sired offspring with consistently higher hatching success and
the effect was repeatable across individual females. Thus, some males provided females with indirect benefits related to additive
genetic quality (“good genes”) and expressed via increased hatching rate, but this benefit was not related to male dominance
status or body size. 相似文献
10.
Dolenec T Serafimovski T Tasev G Dobnikar M Dolenec M Rogan N 《Environmental geochemistry and health》2007,29(1):21-32
The objective of this study was to assess the bulk chemical composition as well as the extent and severity of heavy metal
contamination in the paddy soil of Kočani Field (eastern Macedonia). The results revealed that the paddy soil of the western
part of Kočani Field is severely contaminated with Pb, Zn, As and Cd in the vicinity of the Zletovska River due to irrigation
with riverine water that is severely affected by acid mine and tailing effluents from the Pb–Zn mine in Zletovo. The detected
total concentrations of these metals are far above the threshold values considered to be phytotoxically excessive for surface
soil. The paddy soil in the vicinity of the Zletovska River was also found to exhibit elevated levels of Ba, Th, U, V, W,
Mo, Cu, Sb, Bi, Ag, Au, Hg and Tl, with concentrations above their generally accepted median concentration values obtained
during this study. A correlation matrix revealed that the Mn and Fe oxides/hydroxides are the most important carrier phase
for several trace elements, with the exception of rare earth elements (REEs). These also represent a major sink for the observed
heavy metal pollution of the soil. REEs are mostly associated with two phases: light (L)REEs are bound to K-Al, while heavy
(H)REEs are bound to Mg-bearing minerals. Although there is no direct evidence of a health risk, the paddy soil in the vicinity
of Zletovska River needs further investigation and an assessment should be made of its suitability for agricultural use, particularly
in view of the highly elevated concentrations of Pb, Zn, As and Cd. 相似文献