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1.
The collapse of Soviet Union in early 1990s led to abandonment of large area of arable land which is assumed to act as a carbon (C) sink. We studied the ability of two dynamic soil C models (Yasso07 and RothC) to predict changes in soil C content after cropland abandonment. The performance of the models was compared using the results of a long-term experiment in Pushchino, Moscow region (54°50′N, 37°35′E) in Russia. The experiment was divided in four combinations of fertilizer or mowing treatments on former cropland soil. The soil C content was determined in the year of establishment (1980) and thereafter in 1999 and 2004. The soil C stocks increased by about 1.5- to 1.8-fold during the study period. Both models predicted the overall change in soil C relatively well (modelling efficiency of Yasso07 and RothC were 0.60 and 0.73, respectively). According to the models, the soil gained on average 140–150 g C m?2 year?1 during the first 5 years after conversion of cropland to grassland. The C sequestration rate decreased to 40–50 g C m?2 year?1 after 20 years of land use change. The sequestration rates estimated in this study are comparable to the rates observed in other studies.  相似文献   
2.
External Research Collaboration in Two Small Science Systems   总被引:2,自引:0,他引:2  
This paper compares external research collaboration in small science systems. The design involves studying research collaboration in an independent country (Iceland) and a region of a large country (Newfoundland, Canada). The objective of the paper is firstly to gain a deeper understanding of external research collaboration in small science systems by using both quantitative and qualitative methods and secondly to examine if it is justifiable to compare small regions and small independent countries in terms of their scientific activities. The two science systems are compared with respect to their publication patterns in order to explore how comparable they are in their scientific profiles. External collaboration rates for both science systems are then measured and compared, and it is shown that research collaboration plays an important part in the two science systems. The role of research collaboration is examined further with a combination of bibliometric analysis and interview data. It was found that scientists in small science systems do not collaborate only because they lack economic resources, but an important reason for their collaboration was the availability of research material which was in demand by scientists in the wider scientific world.  相似文献   
3.
A nationwide outbreak of Salmonella enterica serotypes Newport and Reading occurred between 17 October and 28 November 2008 in Finland. A total of 77 culture-confirmed Salmonella Newport and 30 Salmonella Reading cases, including one case with a double infection, were reported. All strains isolated from the patients were subtyped using serotyping, microbial resistance profiling, and pulsed-field gel electrophoresis (PFGE). Here, the PFGE patterns of the studied Salmonella Newport strains were identical, whereas four different PFGE profiles were found among the Salmonella Reading strains. Two elderly patients died within 2 weeks of the onset of symptoms. Three geographical clusters of cases with an epidemiological link were identified. The traceback investigation suggested that the factor connecting the cases was ready-chopped iceberg lettuce available for mass catering use. However, none of the tested food, environmental samples, or the samples taken from the staff of the processing plant contained Salmonella bacteria. Tracing back to outbreak sources with a short shelf life can be complex.  相似文献   
4.
The present study is aimed at examining the combined effects of effort-reward imbalance (ERI), overcommitment (OVC), and perceived organizational support (POS) on turnover intentions and work engagement, among Finnish managers (n = 1,301). Consequently, the study contributes to the research literature by examining how the ERI-outcomes relationship was dependent simultaneously on OVC and POS. The results showed that ERI × OVC × POS interaction was significant only for turnover intentions. The ERI-turnover intentions relationship was strongest under conditions of high OVC and low POS. In addition, the relationship between ERI and decreased work engagement, especially dedication, was strengthened among overcommitted managers, compared to their less committed counterparts. Altogether, the results indicate that interventions aimed at reducing turnover intentions and increasing work engagement by increasing ERI should consider OVC and POS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
5.
The "study was designed to obtain some objective measure of both kinds of conformity… the dynamic process of immediate conformity, termed acquiescence; and long term results of conformity to cultural norms, termed conventionality." 22 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
The addition of antimicrobial preservatives to pharmaceutical and cosmetic products is necessary to prevent microbial growth. However, the use of preservatives can also produce other undesirable effects. For several years, researchers have been investigating the use of alternative methods in safety assessment of cosmetic ingredients and formulations by means of variety methods. The aim of this study was to evaluate the erythrocyte toxicities of two commercial preservatives: imidazolidinyl urea and diazolidinyl urea. Relatively few studies about the cytotoxicity of these preservative are available. The determination of their cytotoxicity is an essential step to warrant their safe use. Erythrocyte toxicities were evaluated by assessment of the amount of hemoglobin released by red blood cells after their lysis. In this study, both imidazolidinyl urea and diazolidinyl urea showed cytotoxic activity against red blood cells. The imidazolidinyl urea induce a small release of hemoglobin after 120 min of incubation. But, the diazolidinyl urea induce a massive release of hemoglobin from the imidazolidinyl urea (a rate of 83% at concentrations of 6.25 mg/mL and 12.5 mg/mL).  相似文献   
7.
Previous research has linked depression to difficulties in smoking cessation. The authors followed 269 smokers who attempted to quit smoking for 3 months. Participants were given nicotine gum (2 or 4 mg) or placebo gum and brief counseling. The study found that 34% of the smokers met the criterion for current depression using the Center for Epidemiological Studies Depression Scale. Depressed smokers relapsed significantly earlier than the nondepressed. Nicotine gum was significantly more effective than placebo gum among all smokers. The benefits of nicotine gum were particularly apparent among the depressed. Only 12.5% of depressed smokers quit successfully with placebo gum for 3 months, whereas 29.5% quit with nicotine gum. Depressed smokers reported more stress, less coping resources, more physical and psychological symptoms, and more frequent smoking in the presence of negative affect than did the nondepressed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
8.
Low-loss optical fibers are now indispensable transmission media for transmission systems. Recently, the ultralow-loss performance for long transmission systems, the water-loss-free performance for wide-band wavelength-division-multiplexing (WDM) systems, the hydrogen-loss-insensitive performance for system reliability, and the bending-loss-insensitive performance for access or indoor applications have attracted much interest. In this regard, pure-silica-core fibers (PSCFs) are suitable, and unprecedented low-loss PSCFs have been successfully fabricated. This paper introduces the recent progress of low-loss PSCFs and their possible impact on transmission systems.  相似文献   
9.
10.
Microfiltered native whey protein (MFNW) exerts superior in vitro functional properties compared to traditional cheese whey protein. We here investigated the metabolic effects of a novel MFNW, produced by economic polymeric membranes and rich in α-lactalbumin (α-lactalbumin 24% and β-lactoglobulin 65% of the protein), in a mice model of diet-induced obesity during weight gain and weight loss. Furthermore, the effects of MFNW were compared with those of α-lactalbumin. Replacement of casein in the diet (18% of energy) by MFNW prevented weight gain and body fat accumulation without influencing food intake, body temperature or glucose homeostasis. However, the anti-obesity effect of MFNW was inferior compared to α-lactalbumin (approximately 1/3). During weight loss (70% of ad libitum energy intake) the beneficial effects of both MFNW and α-lactalbumin were attenuated. Our findings indicate that MFNW protects against diet-induced obesity, and suggest that the beneficial effects of MFNW are due, to a great extent, to its α-lactalbumin content.  相似文献   
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