221 research outputs found
AN EMPIRICAL STUDY ON RELATIONS BETWEEN GOVERNANCE AND SUSTAINABILITY IN BULGARIAN AGRICULTURE
This paper applies the interdisciplinary New Institutional Economics framework, identifies diverse market, private, collective, public and hybrid modes of governance and assesses their impact on agrarian sustainability in Bulgaria. First, the methodological framework of the study is outlined. After that dominating governing modes in Bulgarian farms of different juridical type, size, specialization, ecological and geographical location are identified, and their impacts on agrarian sustainability and its economic, social, and environmental pillars evaluated. In conclusion implications for further research, public policy improvement, and private managerial strategy formation are presented. Agricultural producers of different type use quite unlike mixture of effective market, private, collective and hybrid modes for governance of their activities and relations. Individual factors and modes most contributing to improvement of agrarian sustainability at the current stage of development are: managers personal convictions and initiatives, farms resources and innovation potential, near future profit and benefits strategies, market prices levels and dynamics, area-based EU subsidies, and informal agreements
Multi-band optical variability of three TeV Blazars on Diverse Timescales
We present our optical photometric observations of three TeV blazars, PKS
1510-089, PG 1553+113 and Mrk 501 taken using two telescopes in India, one in
Bulgaria, one in Greece and one in Serbia during 2012 - 2014. These
observations covered a total of 95 nights with a total of 202 B filter frames,
247 images in V band, 817 in R band while 229 images were taken in the I
filter. This work is focused on multi-band flux and colour variability studies
of these blazars on diverse timescales which are useful in understanding the
emission mechanisms. We studied the variability characteristics of above three
blazars and found all to be active over our entire observational campaigns. We
also searched for any correlation between the brightness of the sources and
their colour indices. During the times of variability, no significant evidence
for the sources to display spectral changes correlated with magnitude was found
on timescales of a few months. We briefly discuss the possible physical
mechanisms most likely responsible for the observed flux variability.Comment: 11 pages, 7 figures, 9 tables. Accepted for publication in MNRA
Governing of Agro-Ecosystem Services
In this paper we incorporate interdisciplinary New Institutional and Transaction Costs Economics (combining Economics, Organization, Law, Sociology, Behavioral and Political Sciences), and suggest a framework for analysis of mechanisms of governance of agro-ecosystem services. Firstly, we present a new approach for analysis and improvement of governance of agro-ecosystem services. It takes into account the role of specific institutional environment (formal and informal rules, distribution of rights, systems of enforcement); and behavioral characteristics of individual agents (preferences, bounded rationality, opportunism, risk aversion, trust); and transactions costs associated with ecosystem services and their critical factors (uncertainty, frequency, asset specificity, appropriability); and comparative efficiency of market, private, public and hybrid modes of governance. Secondly, we identify spectrum of market and private forms of governance of agro-ecosystem services (voluntary initiatives; market trade with eco-products and services; special contractual arrangements; collective actions; vertical integration), and evaluate their efficiency and potential. Next, we identify needs for public involvement in the governance of agro-ecosystem services, and assess comparative efficiency of alternative modes of public interventions (assistance, regulations, funding, taxing, provision, partnership, property right modernization).
Finally, we analyze structure and efficiency of governance of agro-ecosystems services in Zapadna Stara Planina – a mountainous region in North-West Bulgaria. Post-communist transition and EU integration has brought about significant changes in the state and governance of agro-ecosystems services. Newly evolved market, private and public governance has led to significant improvement of part of agro-ecosystems services introducing modern eco-standards and public support, enhancing environmental stewardship, desintensifying production, recovering landscape and traditional productions, diversifying quality, products, and services. At the same time, novel governance is associated with some new challenges such as unsustainable exploitation, lost biodiversity, land degradation, water and air contamination. What is more, implementation of EU common policies would have no desired impact on agro-ecosystem services unless special measures are taken to improve management of public programs, and extend public support to dominating small-scale and subsistence farms
Average UV Quasar Spectra in the Context of Eigenvector 1: A Baldwin Effect Governed by Eddington Ratio?
We present composite UV spectra for low redshift Type 1 AGN binned to exploit
the information content of the Eigenvector 1 (E1) parameter space. Composite
spectra allow a decomposition of the CIV1549 line profile - one of the
strongest high-ionization lines. The simplest CIV decomposition into narrow
(NLR), broad (BLR) and very broad (VBLR) components suggests that different
components have an analog in Hb with two major exceptions. VBLR emission is
seen only in population B (FWHM(Hb)>4000 km/s) sources. A blue
shifted/asymmetric BLR component is seen only in pop. A (FWHM(Hb)<4000 km/s)
HIL such as CIV. The blueshifted component is thought to arise in a wind or
outflow. Our analysis suggests that such a wind can only be produced in pop. A
(almost all radio-quiet) sources where the accretion rate is relatively high.
Comparison between broad UV lines in radio-loud (RL) and radio-quiet (RQ)
sources shows few significant differences. Clear evidence is found for a narrow
CIV component in most radio-loud sources. We find also some indirect
indications that the black hole (BH) spin, rather than BH mass or accretion
rate is a key trigger in determining whether an object will be RL or RQ. We
find a ten-fold decrease in EW CIV with Eddington ratio (decreasing from ~1 to
\~0.01) while NV shows no change. These trends suggest a luminosity-independent
"Baldwin effect" where the physical driver may be the Eddington ratio.Comment: 39 pages, 6 figures. To appear in Ap
Radio Loud AGN in the Context of the Eigenvector 1 Parameter Space
We consider the properties of radio-loud (RL) AGN in the context of the
Eigenvector 1 (E1) parameter space. RL sources show a restricted E1 parameter
space occupation relative to the radio-quiet (RQ) majority. The Fanaroff-Riley
II ``parent population'' of relatively un-boosted RL sources (median
radio/optical flux ratio ~490) shows the most restricted occupation. RL sources
have different broad line properties (and inferred black hole masses and
Eddington ratios). FWHM H_beta for the broad line component in RL sources are
at least twice as large as the RQ majority. The average broad FeII emission
line strength is also about half that for RQ sources. Our sample suggests that
the RL cutoff occurs near R_k=70 or logP(6cm)=32.0 ergs/s/Hz. Sources below
this cutoff are RQ although we cannot rule out the existence of a distinct
intermediate population. We show that the Doppler boosted core-dominated RL
sources (median flux ratio ~1000) lie towards smaller FWHM(H_beta_bc) and
stronger FeII in E1 as expected if the lines arise in an accretion disk. Our
subsample of superluminal sources, with orientation inferred from the
synchrotron self Compton model, reinforce this general E1 trend and allow us to
estimate the role of source orientation in driving E1 domain occupation.Comment: 9 pages, 3 figures, accepted for publication in ApJ
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