Formica subnuda is a facultative slave-making ant, and colonies without slaves are often found. We studied the effect of slave workers on
sexual production of F. subnuda by experimentally increasing the proportion of slaves. We added c. 4000 worker pupae of the ant F. podzolica to 15 F. subnuda colonies and kept 15 colonies as controls. The following year we excavated all colonies, counted the proportion of slaves,
the total number of workers (colony size) and the number of sexual offspring. The proportion of slaves was significantly higher
in the slave-added colonies than in the control colonies. The total production of sexual offspring increased 57% in the treatment
colonies in comparison to the controls. When colony size was adjusted to the number of sexual offspring, the treatment colonies
produced significantly more sexual offspring than the controls. Slave addition did not alter sex ratios. We suggest that two
alternative mechanisms, not mutually exclusive, caused the increase of sexual production in F. subnuda colonies: (1) Most of the added pupae were consumed and stored as fat body in workers at the end of the experimental year;
the following spring the excess fat was metabolized and fed to the developing sexual larvae, or (2) a proportion of the added
pupae hatched to become slaves; the following spring these slaves foraged actively for protein-rich food for the developing
sexual offspring.
Received: 27 April 1995/Accepted after revision: 23 October 1995 相似文献
This study examined changes in work techniques and musculoskeletal symptoms after occupationally oriented medical rehabilitation arranged for 21 hairdressers who were experiencing neck-shoulder or back pain but were still able to work. OWAS (Ovako Working Posture Analysing System) analyses of working postures and questionnaire data were obtained at the beginning of the courses and one and a half years later. The participants worked with their back bent and twisted or their arms at or over shoulder level more seldom (p < .0001) at the end of the follow-up than at the beginning of the rehabilitation. Subjective work-related physical and mental strain had decreased by 45.4% (p < .001) and 27.1% (p < .05), respectively, and subjective neck and back pain by 40.0% (p < .0 1 ) and 45.3% (p < .01). respectively. This’study suggests that occupationally oriented medical rehabilitation can have significant and long-lasting effects on the rehabilitee’s work techniques and subjective well-being. 相似文献
The transfer of 137Cs into fish in seepage and drainage lakes from 1988 to 1992 was analysed using linear regression. Empirical results for 137Cs in lake water and fish were used to calculate concentration factors (CFs). In the drainage lakes the CF decreased during the study period by 9% per year whereas in the seepage lakes the CF increased significantly by 4.3% per year. The transfer of 137Cs into pike was significantly (1.6 times) higher than that into perch. The CF increased on average by 3.4% for each 1-cm increase in the median size of perch. The relationship between the water chemistry and the CF differed between clear-water seepage and brown-water drainage lakes. 相似文献
The accident at the Chernobyl nuclear power plant in 1986 significantly elevated the 137Cs levels of fish in Finnish lakes. About 6200 fish samples from 390 lakes comprising 20 species have been analysed for 137Cs since 1986. The sizes of the lakes varied from a few hectares to about 1000 km2. Activity concentrations of 137Cs in fish still varied widely in 2003, from 16 to 6400 Bq/kg fresh weight. This paper presents the results of statistical analyses with multivariate linear regression models carried out on the empirical data collected since 1986. The statistical analysis resulted in separate models for two time periods describing temporal changes of 137Cs in fish. The explanatory variables were fish species with various feeding habits, the size class of the lake, municipal division, drainage area, time since the deposition and deposition level of the municipality. The calculated values for 137Cs in fish did not differ statistically significantly from the observed values in the validation data. The explanatory variables explained 58% (the first time period) and 72% (the second time period) of the total variability of 137Cs in fish. 相似文献
Carbon dioxide emission reduction scenarios for Finland are compared with respect to the radiative forcing they cause (heating
power due to the absorption of infrared radiation in the atmosphere). Calculations are made with the REFUGE system model using
three carbon cycle models to obtain an uncertainity band for the development of the atmospheric concentration.
The future emissions from the use of fossil fuels in Finland are described with three scenarios. In the reference scenario
(business-as-usual), the emissions and the radiative forcing they cause would grow continuously. In the scenario of moderate
emission reduction, the emissions would decrease annually by 1% from the first half of the next century. The radiative forcing
would hardly decrease during the next century, however. In the scenario of strict emission reductions, the emissions are assumed
to decrease annually by 3%, but the forcing would not decrease until approximately from the middle of the next century depending
on the model used. Still, in the year 2100 the forcing would be considerably higher than the forcing in 1990. Due to the slow
removal of CO2 from the atmosphere by the oceans, it is difficult to reach a decreasing radiative forcing only by limiting fossil CO2 emissions.
The CO2 emissions from fossil fuels in Finland contribute to the global emissions presently by about 0.2%. The relative contribution
of Finnish CO2 emissions from fossil fuels to the global forcing due to CO2 emissions is presently somewhat less than 0.2% due to relatively smaller emissions in the past. The impact of the nonlinearity
of both CO2 removal from the atmosphere and of CO2 absorption of infrared radiation on the results is discussed. 相似文献
Objectives: Methiopropamine (MPA; 1-(thiophen-2-yl)-2-methylaminopropane) belongs to the new psychoactive substances (NPS) that have emerged on the drug market in recent years. MPA appeared in 2011 and is an analogue of methamphetamine, sold as, for example, "Slush Eric"and "Blow." It is reported to have effects similar to those of methamphetamine, but the toxicity in humans is not known. Three fatal cases involving MPA have been reported. One analytical confirmed intoxication case has been published, and this supports the symptoms described by the users. The prevalence of recreational use of MPA is unknown, and no studies have reported the prevalence in driving under the influence of drug (DUID) cases.
Methods: We investigated the frequency of MPA in DUID cases received at our institute during a 12-week period and report the analytical method using an ultraperformance liquid chromatography.tandem mass spectrometry for quantification of MPA in whole blood. The analytical findings were compared to the results from a clinical test of impairment performed by a physician shortly after the driving episode. The samples were analyzed for 42 different psychoactive substances.
Results: MPA was detected in 10 DUID cases (0.8% of the cases), only from male drivers. Other drugs were detected concomitantly in all the cases. Two of the cases were traffic accidents.
Conclusions: Our study shows that MPA is found in DUID cases and reveals that NPS are used among drivers and also proven in blood from drivers involved in traffic accidents. More studies are requested regarding the pharmacological and toxicological effects of MPA and other NPS. This is the first article that describes a method for analyzing and quantifying MPA in whole blood samples. 相似文献
This contribution to the Journal of Cleaner Production special issue ‘Applications of Industrial Ecology’ is based upon an extensive literature review, which produced four criteria to characterise research on the concept of industrial ecology (IE). The criteria are (1) material and energy flows, (2) systems improvement, (3) systems adaptation and (4) change management. The criteria were analysed against the six subject areas of the Technology and Climate Change (CLIMTECH) Research Programme in Finland to identify the applications of the concept of industrial ecology. The results of the analysis contribute (a) to the debate on the characteristics of the emerging concept of IE, (b) show IE characteristics of a large Finnish research project in the field of climate change mitigation and (c) invite scholars in the field to study the observed unclear and fuzzy role of the concept of IE in practical research project work. Responses to this article are encouraged for publication in the future issues of Journal of Cleaner Production. 相似文献
Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels. 相似文献
The long-term behavior of 90Sr was investigated from 1987 to 1997 in fifteen lakes in southern and central Finland following the 1986 Chernobyl accident. Both water and fish samples (perch, pike, vendace) were analyzed. 90Sr stays long in the freshwater ecosystem; the observed half-lives during the study period were generally around 10 years in water and even longer in fish. One lake exhibited very different behavior for 90Sr, with elevated levels in fish and water and very short observed half-life in fish, less than 2 years. Concentration factors of 90Sr in fish (Bqkg−1 f.w. in fish/Bqkg−1 in water) among the studied lakes significantly correlated with both the Ca concentration and electrical conductivity of the water. More 90Sr was transferred into fish in lakes with a low electrical conductivity and a low Ca concentration. Among other water parameters evaluated were pH, color, total nitrogen, and phosphorus. 相似文献