City dwelling wild bees: how communal gardens promote species richness

Urban areas consist of wide expanses of impervious surfaces which are known to negatively affect insect biodiversity in general, but green spaces within cities have the potential to provide necessary habitat and foraging resources. Although, communal gardens were primarily intended to provide fresh, regional food to denizens, these green islands also host a surprisingly high number of wild bee species.

The gardens were characterized based on structural elements such as flower frequency, the relative percentage of lawn, trees, shrubs, planted crops and infrastructure (e.g. seating possibilities or garden houses). Further, the effects of different landscape structures surrounding the gardens and distance to the city center were analyzed on the total wild bee species richness and functional traits. Focusing on these putative influencing factors, statistical analyses calculating random decision forests along with generalized linear mixed models were applied. With 113 observed wild bee species, communal gardens provide habitat for a quarter of all known species in Vienna. In conclusion, results revealed that only elements within the gardens had an effect on species richness, with flower frequency as the major positive driver. The examined communal gardens promote and conserve wild bees independent from the location within the city or garden size. Furthermore, these green patches are important sanctuaries, hosting rare and threatened species as well as remarkably special wild bee communities.

     

Elements of life satisfaction among young adults in Serbia

Contemporary sociological studies argue that employment and personal life have diversified effects as determinants of life satisfaction (LS) of young adults. We have, therefore, decided to explore the three different aspects of general LS, satisfaction with personal (intimate) domain, satisfaction with family life and satisfaction with occupation (professional domain), by using the survey data on 1627 young adults aged from 19 to 35 from Serbia. The correlations between the three domains are significant, while the strongest tie is between satisfaction with intimate relations and satisfaction with family life. The analysis exposed that social variables (employment, education, housing autonomy and financial autonomy) and personal variables (partnership and parenthood) are in a diverse manner related to the three domains of LS, as well as that their effects are different for young men and women. Taking into account particularities of social context in Serbia, we have introduced functional autonomy (decision-making and acting independent of parents) as mediating variable. The results uncover that functional autonomy has little influence on satisfaction with occupation, while social variables have a strong effect, suggesting that agency in professional domain is significantly socially bound. Regression models reveal divergent and gender-specific relations of variables and three aspects of LS related to particular structural and cultural context in Serbia that sets limits to gender detraditionalization.     

Organizational design as a driver for firm innovativeness in Serbia

The area of innovation and innovation activities includes numerous aspects and changes needed to increase and improve the innovation potential of firms. Besides technological changes, organizational changes also play a very important role. Although these changes are considered within a wider innovation concept that is not limited merely to technological changes, they can significantly influence business improvement. Statistical data processing of an official pilot study – conducted by Statistical Office of the Republic of Serbia in cooperation with the Mihajlo Pupin Institute – illustrates the significance of organizational design regarding the innovative behavior of a company. It also points out that some elements of organizational design give a remarkable impetus to the innovative behavior of corporations, while others can be seen as a limiting factor. Detailed statistical analysis shows that one component of organizational design, namely the introduction of a new or significantly improved knowledge management system for a better use or exchange of information, knowledge and skills within companies, has the most influence on the innovation behavior of the company. Another component, a firm's completely new or significantly different relation with other firms or public institutions (such as alliances, partnerships, outsourcing or sub-contracting), has the least influence. These analyses are of crucial importance for defining the innovation pattern related to corporation management.     

Privatisation Effects: Some Evidence from Serbia

This paper analyses basic outcome and effects of the privatisation process in Serbia. The first two parts of the paper deal with general achievements of the newest privatisation plan adopted in 2001. We present a brief background of the results of the privatisation process, analysing changes in the structure of enterprises by ownership status, the number of privatised firms, revenues earned through privatisation, the rate of successful transactions, and other relevant privatisation indicators. The paper continues with an analysis of a survey conducted within a sample of Serbian enterprises offering some evidence about performance, competition, and restructuring within different types of firms: socially owned, privatised, and new private. Contrary to the broadly accepted statement that new private firms are leading in transition economies, according to our estimation of the effects of the ownership type on firm performance, it appears that the privatised sector seems to be more active. A comparison of the survey results with findings for three neighbouring countries indicates that there is no general conclusion about the way how ownership status of a firm affects its performance in a transition economy. Although conclusions drawn from our survey analysis should be regarded as preliminary and limited by the quality of survey data and could not be generalised for the privatisation process in other transition countries, the findings we present, including the comparison made with other economies, could contribute to the understanding of both privatisation effects in general and effects remarkable for the Serbian economy.      

Forecasting Spanish Natural Life Expectancy

Knowledge of trends in life expectancy is of major importance for policy planning. It is also a key indicator for assessing future development of life insurance products, substantiality of existing retirement schemes, and long-term care for the elderly. This article examines the feasibility of decomposing age-gender-specific accidental and natural mortality rates. We study this decomposition by using the Lee and Carter model. In particular, we fit the Poisson log-bilinear version of this model proposed by Wilmoth and Brouhns et al. to historical (1975-1998) Spanish mortality rates. In addition, by using the model introduced by Wilmoth and Valkonen we analyze mortality-gender differentials for accidental and natural rates. We present aggregated life expectancy forecasts compared with those constructed using nondecomposed mortality rates.     

Stochastic approximation methods in linear regression models (with consideration of errors in the regressors) 1

Usually, the dependence in stationary processes is described by a set of coefficients. In this paper, a measure of dependence is proposed which can be used instead of the autocorrelation function, and another measure for the dependence between two processes instead of cross-correlation function and coherence coefficients. In the end, an improvement of extrapolation of a process is investigated which is caused by the knowledge of another related process.