1,721,100 research outputs found
A 20 YRS-LONG ANALYSIS OF THE MACROBENTHOS IN A LTER SITE: THE VALLI DI COMACCHIO STUDY CASE
No full textThe analysis of the benthic community of the Valli di Comacchio revealed similar general patterns across all studied sites, albheit strong interannual variability was evident. The ecological quality status resulted almost constantly unsatisfactory: the overlapping effects of natural and anthropogenic disturbance may challange the environmental assessment of the Valli
A new species of Protodorvillea (Polychaeta: Dorvilleidae) from the Western Mediterranean Sea
No full textA new species of Dorvilleidae, Protodorvillea artemidis sp. nov., is described from the soft bottom of the Gulf of Taranto (northern Ionian Sea) and the Straits of Messina (southern Tyrrhenian Sea), in the western Mediterranean Sea. The specimens were collected in October 2014, near the village of Rossano Calabro (Southern Italy, Ionian Sea), and in July 2016 off the village of Scilla (Southern Italy, Tyrrhenian Sea), from 6 to 38 m depth. Protodorvillea artemidis sp. nov. is characterised by four eyes, two short clavate antennae, dorsal and ventral cirri from the first parapodium, a long subacicular falciger reminiscent of that of Dorvillea, and the simultaneous occurrence of supraacicular and subacicular cultriform chaetae with serrated edges. Protodorvillea artemidis sp. nov. is similar to P. kefersteini (McIntosh, 1869) but differs from this species mainly by morphological characteristics of prostomium, mouth parts, and supraacicular and subacicualar chaetae. Morphological characters important for differentiation of the new species herein described from congeneric species are discussed. The description of P. artemidis sp. nov. helps to improve the knowledge on the diversity of Mediterranean invertebrates, and specifically on the family Dorvilleidae, which is still poorly known and includes many opportunistic species, early indicators of pollution. urn:lsid:zoobank.org:pub:AC147ADF-762A-4797-A9AE-FC0BA1219D1A
Multi-utility representations of incomplete preferences induced by set-valued risk measures
Full text linkWe establish a variety of numerical representations of preference relations induced by set-valued risk measures. Because of the general incompleteness of such preferences, we have to deal with multi-utility representations. We look for representations that are both parsimonious (the family of representing functionals is indexed by a tractable set of parameters) and well behaved (the representing functionals satisfy nice regularity properties with respect to the structure of the underlying space of alternatives). The key to our results is a general dual representation of set-valued risk measures that unifies the existing dual representations in the literature and highlights their link with duality results for scalar risk measures
Unexpected shortfalls of Expected Shortfall: Extreme default profiles and regulatory arbitrage
No full textThe purpose of this paper is to dispel some common misunderstandings about capital adequacy rules based on Expected Shortfall. We establish that, from a theoretical perspective, Expected Shortfall based regulation can provide a misleading assessment of tail behavior, does not necessarily protect liability holders' interests much better than Value-at-Risk based regulation, and may also allow for regulatory arbitrage when used as a global solvency measure. We also show that, for a value-maximizing financial institution, the benefits derived from protecting its franchise may not be sufficient to disincentivize excessive risk taking. We further interpret our results in the context of portfolio risk measurement. Our results do not invalidate the possible merits of Expected Shortfall as a risk measure but instead highlight the need for its cautious use in the context of capital adequacy regimes and of portfolio risk control. (C) 2015 Elsevier B.V. All rights reserved
Beyond cash-additive risk measures: When changing the numeraire fails
No full textWe discuss risk measures representing the minimum amount of capital a financial institution needs to raise and invest in a pre-specified eligible asset to ensure it is adequately capitalized. Most of the literature has focused on cash-additive risk measures, for which the eligible asset is a risk-free bond, on the grounds that the general case can be reduced to the cash-additive case by a change of numéraire. However, discounting does not work in all financially relevant situations, especially when the eligible asset is a defaultable bond. In this paper, we fill this gap by allowing general eligible assets. We provide a variety of finiteness and continuity results for the corresponding risk measures and apply them to risk measures based on Value at Risk and Tail Value at Risk on Lebesgue spaces, as well as to shortfall risk measures on Orlicz spaces. We pay special attention to the property of cash subadditivity, which has been recently proposed as an alternative to cash additivity to deal with defaultable bonds. For important examples, we provide characterizations of cash subadditivity and show that when the eligible asset is a defaultable bond, cash subadditivity is the exception rather than the rule. Finally, we consider the situation where the eligible asset is not liquidly traded and the pricing rule is no longer linear. We establish when the resulting risk measures are quasiconvex and show that cash subadditivity is only compatible with continuous pricing rules
Distribution of microplastic fine particles in sediments from the Venice and Goro Lagoons
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Family stress, resources and perceived efficacy in parents of children with disabilities. Duchenne Muscular Distrophy vs Intellectual Disability.
No full textExploratory Structure Equation Modeling of loneliness dimensions in relation to self-esteem, adult attachment, and social anxiety in young adults
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