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The politics of vulnerability and resilience
Frerks, Georg;Warner, Jeroen;Weijs, Bart;
Ambiente & Sociedade , 2011, DOI: 10.1590/S1414-753X2011000200008
Abstract: much conceptual confusion exists over the concepts of vulnerability and (social) resilience, reinforced by the different paradigms (the article identifies four) and disciplinary traditions underlying their use. while since the 1980s the social construction of "vulnerability" as a driver for disaster received considerable attention, in recent years we have seen increased attention to people's capacities and resilience. the currently popular "complexity" approach to risk moreover appears to offer ways of breaking through entrenched vulnerabilities. resilience however is also a political project which, we argue, also has its dark, conservative overtones and overlooks structural sources of vulnerability that continue to affect hazard-prone actors. we may therefore need to conceive resilience as the potential for social transformation after disaster.
Individual prey choices of octopuses: Are they generalist or specialist?  [cached]
Jennifer A. MATHER, Tatiana S. LEITE, Allan T. BATISTA
Current Zoology , 2012,
Abstract: Prey choice is often evaluated at the species or population level. Here, we analyzed the diet of octopuses of different populations with the aim to assess the importance of individual feeding habits as a factor affecting prey choice. Two methods were used, an assessment of the extent to which an individual octopus made choices of species representative of those population (PSi and IS) and 25% cutoff values for number of choices and percentage intake of individual on their prey. In one population of Octopus cf vulgaris in Bermuda individuals were generalist by IS=0.77, but most chose many prey of the same species, and were specialists on it by >75% intake. Another population had a wider prey selection, still generalist with PSi=0.66, but two individuals specialized by choices. In Bonaire, there was a wide range of prey species chosen, and the population was specialists by IS= 0.42. Individual choices revealed seven specialists and four generalists. A population of Octopus cyanea in Hawaii all had similar choices of crustaceans, so the population was generalist by IS with 0.74. But by individual choices, three were considered a specialist. A population of Enteroctopus dofleini from Puget Sound had a wide range of preferences, in which seven were also specialists, IS=0.53. By individual choices, thirteen were also specialists. Given the octopus specialty of learning during foraging, we hypothesize that both localized prey availability and individual personality differences could influence the exploration for prey and this translates into different prey choices across individuals and populations showed in this study [Current Zoology 58 (4): 597-603, 2012].
Population Genetic Structure of a Sandstone Specialist and a Generalist Heath Species at Two Levels of Sandstone Patchiness across the Strait of Gibraltar  [PDF]
Manuel Jesús Gil-López, José Gabriel Segarra-Moragues, Fernando Ojeda
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0098602
Abstract: Many habitat specialist species are originally composed of small, discontinuous populations because their habitats are naturally fragmented or patchy. They may have suffered the long-term effects of natural patchiness. Mediterranean heathlands, a representative habitat in the Strait of Gibraltar region, are associated with nutrient-poor, acidic sandstone soils. Sandstone soil patches in the African side of the Strait (Tangier) are, in general, smaller and more scattered than in the European side (Algeciras). In this study, we analyze the effect of this sandstone patchiness on the population genetic diversity and structure of two Erica species from these Mediterranean heathlands that differ in their edaphic specificity, E. australis, sandstone specialist, and E. arborea, generalist. Average levels of within-population genetic diversity and gene flow between populations were significantly lower in Tangier (high sandstone patchiness) than in Algeciras (low patchiness) for the sandstone specialist, whereas no differences between both sides of the Strait were detected in the edaphic generalist. Since most endemic species in Mediterranean heathlands of the Strait of Gibraltar are sandstone specialists, these results highlight an increased vulnerability to loss of genetic diversity and local extinction of the heathland endemic flora in the Tangier side of the Strait of Gibraltar.
Influences of Plant Traits on Immune Responses of Specialist and Generalist Herbivores  [PDF]
Evan Lampert
Insects , 2012, DOI: 10.3390/insects3020573
Abstract: Specialist and generalist insect herbivore species often differ in how they respond to host plant traits, particularly defensive traits, and these responses can include weakened or strengthened immune responses to pathogens and parasites. Accurate methods to measure immune response in the presence and absence of pathogens and parasites are necessary to determine whether susceptibility to these natural enemies is reduced or increased by host plant traits. Plant chemical traits are particularly important in that host plant metabolites may function as antioxidants beneficial to the immune response, or interfere with the immune response of both specialist and generalist herbivores. Specialist herbivores that are adapted to process and sometimes accumulate specific plant compounds may experience high metabolic demands that may decrease immune response, whereas the metabolic demands of generalist species differ due to more broad-substrate enzyme systems. However, the direct deleterious effects of plant compounds on generalist herbivores may weaken their immune responses. Further research in this area is important given that the ecological relevance of plant traits to herbivore immune responses is equally important in natural systems and agroecosystems, due to potential incompatibility of some host plant species and cultivars with biological control agents of herbivorous pests.
Health education: the role and functions of the specialist and the generalist
Cleary,Helen P.;
Revista de Saúde Pública , 1988, DOI: 10.1590/S0034-89101988000100009
Abstract: education for health is a process in which all public health and medical care personnel are involved. people learn both formally (planned learning experiences) and informally (unplanned learning experiences). since the patient, the client, the consummer and the community expect public health and medical care personnel to assist them with health and disease issues and problems, the response of the professional "educates" the customer whether the professional intends to educate or not. therefore, it is incumbent on all public health and medical care professionals to understand their educational functions and their role in health education. it is also important that the role of the specialist in education be clear. the specialist, as to all other specialists, has an in-depth knowledge of his area of expertise, i.e., the teaching/learning process; s/he may function as a consultant to others to enhance the educational potential of their role or s/he may work with a team or with communities or groups of patients. specific competencies and knowledge are required of the health education specialist; and there is a body of learning and social change theory which provides a frame of reference for planning, implementing and evaluating educational programs. working with others to enhance their potential to learn and to make informed decisions about health/disease issues is the hallmark of the health education specialist.
Resilience and Vulnerability: Complementary or Conflicting Concepts?
Fiona Miller,Henny Osbahr,Emily Boyd,Frank Thomalla
Ecology and Society , 2010,
Abstract: Resilience and vulnerability represent two related yet different approaches to understanding the response of systems and actors to change; to shocks and surprises, as well as slow creeping changes. Their respective origins in ecological and social theory largely explain the continuing differences in approach to social-ecological dimensions of change. However, there are many areas of strong convergence. This paper explores the emerging linkages and complementarities between the concepts of resilience and vulnerability to identify areas of synergy. We do this with regard to theory, methodology, and application. The paper seeks to go beyond just recognizing the complementarities between the two approaches to demonstrate how researchers are actively engaging with each field to coproduce new knowledge, and to suggest promising areas of complementarity that are likely to further research and action in the field.
Contrasting Infection Strategies in Generalist and Specialist Wasp Parasitoids of Drosophila melanogaster  [PDF]
Todd A Schlenke ,Jorge Morales,Shubha Govind,Andrew G Clark
PLOS Pathogens , 2007, DOI: 10.1371/journal.ppat.0030158
Abstract: Although host–parasitoid interactions are becoming well characterized at the organismal and cellular levels, much remains to be understood of the molecular bases for the host immune response and the parasitoids' ability to defeat this immune response. Leptopilina boulardi and L. heterotoma, two closely related, highly infectious natural parasitoids of Drosophila melanogaster, appear to use very different infection strategies at the cellular level. Here, we further characterize cellular level differences in the infection characteristics of these two wasp species using newly derived, virulent inbred strains, and then use whole genome microarrays to compare the transcriptional response of Drosophila to each. While flies attacked by the melanogaster group specialist L. boulardi (strain Lb17) up-regulate numerous genes encoding proteolytic enzymes, components of the Toll and JAK/STAT pathways, and the melanization cascade as part of a combined cellular and humoral innate immune response, flies attacked by the generalist L. heterotoma (strain Lh14) do not appear to initiate an immune transcriptional response at the time points post-infection we assayed, perhaps due to the rapid venom-mediated lysis of host hemocytes (blood cells). Thus, the specialist parasitoid appears to invoke a full-blown immune response in the host, but suppresses and/or evades downstream components of this response. Given that activation of the host immune response likely depletes the energetic resources of the host, the specialist's infection strategy seems relatively disadvantageous. However, we uncover the mechanism for one potentially important fitness tradeoff of the generalist's highly immune suppressive infection strategy.
Unbiased Transcriptional Comparisons of Generalist and Specialist Herbivores Feeding on Progressively Defenseless Nicotiana attenuata Plants  [PDF]
Geetha Govind,Omprakash Mittapalli,Thasso Griebel,Silke Allmann,Sebastian B?cker,Ian Thomas Baldwin
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0008735
Abstract: Herbivore feeding elicits dramatic increases in defenses, most of which require jasmonate (JA) signaling, and against which specialist herbivores are thought to be better adapted than generalist herbivores. Unbiased transcriptional analyses of how neonate larvae cope with these induced plant defenses are lacking.
A specialist-generalist classification of the arable flora and its response to changes in agricultural practices
Guillaume Fried, Sandrine Petit, Xavier Reboud
BMC Ecology , 2010, DOI: 10.1186/1472-6785-10-20
Abstract: We used data derived from an extensive national monitoring network of approximately 700 arable fields scattered across France to quantify the degree of specialisation of 152 weed species using six different ecological methods. We then explored the impact of the level of disturbance occurring in arable fields by comparing the degree of specialisation of weed communities in contrasting field situations.The classification of species as specialist or generalist was consistent between different ecological indices. When applied on a large-scale data set across France, this classification highlighted that monoculture harbour significantly more specialists than crop rotations, suggesting that crop rotation increases abundance of generalist species rather than sets of species that are each specialised to the individual crop types grown in the rotation. Applied to a diachronic dataset, the classification also shows that the proportion of specialist weed species has significantly decreased in cultivated fields over the last 30 years which suggests a biotic homogenization of agricultural landscapes.This study shows that the concept of generalist/specialist species is particularly relevant to understand the effect of anthropogenic disturbances on the evolution of plant community composition and that ecological theories developed in stable environments are valid in highly disturbed environments such as agro-ecosystems. The approach developed here to classify arable weeds according to the breadth of their ecological niche is robust and applicable to a wide range of organisms. It is also sensitive to disturbance regime and we show here that recent changes in agricultural practices, i.e. increased levels of disturbance have favoured the most generalist species, hence leading to biotic homogenisation in arable landscapes.The concept of ecological niche as a hypothetical multidimensional space [1] has boosted the exploration of niche properties [2-4] and has enabled generalist and spe
Economic Vulnerability and Resilience of Small Island States
Te’o I. J. Fairbairn
Island Studies Journal , 2007,
Abstract: This essay assesses the principles of economic vulnerability and resilience and their contribution to the study and development of small island developing states (SIDS). It is based on a detailed critical account of the contents of a recent publication - Briguglio & Kisanga (2004) - that addresses this issue. It is thus an extended book review that examines arguments central to many current mainstream considerations of small island economies.
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