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Survival Strategies (survival + strategy)
Selected AbstractsThe Construction of the Myth of SurvivalDEVELOPMENT AND CHANGE, Issue 1 2007Mercedes González de la Rocha ABSTRACT A myth has come into being that the poor household/family is able to survive in spite of a lack of resources and the presence of macroeconomic policies that foster unemployment and poverty. It has an accompanying fable that tells of how the poor manage to implement survival strategies that are based on their endless capacity to work, to consume less and to be part of mutual help networks. This myth has become a useful tool for policy makers as they design more aggressive neoliberal economic adjustment policies. This contribution examines anthropological and sociological insights regarding the life of the poor and the organization of their households, in which women's paid and unpaid work is an integral part. Through the lens of a researcher in the field of urban poverty and household organization, the article re-examines the fable of the good survivor. Evidence debunks the myth, showing that the optimistic message of this fable does not match with the realities of the impact of economic change on women's lives. But the myth is sustained, as this more negative story is not one that supra-national policy actors want to hear. [source] Cyclone disaster vulnerability and response experiences in coastal BangladeshDISASTERS, Issue 4 2010Edris Alam For generations, cyclones and tidal surges have frequently devastated lives and property in coastal and island Bangladesh. This study explores vulnerability to cyclone hazards using first-hand coping recollections from prior to, during and after these events. Qualitative field data suggest that, beyond extreme cyclone forces, localised vulnerability is defined in terms of response processes, infrastructure, socially uneven exposure, settlement development patterns, and livelihoods. Prior to cyclones, religious activities increase and people try to save food and valuable possessions. Those in dispersed settlements who fail to reach cyclone shelters take refuge in thatched-roof houses and big-branch trees. However, women and children are affected more despite the modification of traditional hierarchies during cyclone periods. Instinctive survival strategies and intra-community cooperation improve coping post cyclone. This study recommends that disaster reduction programmes encourage cyclone mitigation while being aware of localised realities, endogenous risk analyses, and coping and adaptation of affected communities (as active survivors rather than helpless victims). [source] Megaplasmids in Gram-negative, moderately halophilic bacteriaFEMS MICROBIOLOGY LETTERS, Issue 1 2003Montserrat Argandoña Abstract We have discovered that many Halomonas species harbour large extrachromosomal DNA elements. Using currently available protocols it is technically very difficult to identify large plasmids in bacteria, and even more so when they are coated in mucous polysaccharide. We used culture conditions suitable for both halophilic and halophilic exopolysaccharide-producing bacteria and applied a modified gel electrophoresis method to locate and visualise the megaplasmids. Almost all the species of Halomonas studied harbour two plasmids of about 70 kb and 600 kb and some species carry other smaller extrachromosomal DNA elements. The common presence of these megaplasmids may well be related to the survival strategies of the bacteria in their special surroundings. [source] Marginalized for a lifetime: The everyday experiences of gulag survivors in post-Soviet MagadanGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 1 2006John Round Abstract Over the past decade notions of social capital have become embedded in the social development lexicon, often presented as the ,missing link' within development theory. Much social capital-based research takes Robert Putnam's theorization of the subject as its starting point. Putnam's work argues that social capital can be measured by a region's levels of trust and civic engagement. While its use, and conceptualization, has undergone much academic debate, often formal institutions still employ this very narrow, and arguably Western-centric, reading of the subject. This paper argues that while at the micro-level social capital has little to do with the civic engagement and trust theories posited by Putnam, it still has relevance to the lives of marginalized individuals and is an important factor in their continued survival. To explore this, drawing on extensive qualitative research conducted in Magadan, Moscow and St Petersburg, I critically examine the construction of everyday survival strategies among Gulag survivors living in Russia's far northeast city of Magadan. Denied a return to their ,homeland' upon their release, this group experienced considerable marginalization in the post-Stalin period. This was exacerbated when the collapse of the Soviet Union saw pensions in the far northeast of Russia fall to below 50% of the state-set subsistence minimum. The paper demonstrates the importance of social capital to this group by showing how their survival is based on far more than interactions with formal and informal organizations. [source] Pathogenesis of Helicobacter pylori InfectionHELICOBACTER, Issue 2004Paul Hofman ABSTRACT Research in the last year has provided new insights into the function of the the cag -associated type IV secretion system and the vacuolating toxin VacA. A quite new aspect was disclosed by the finding that Helicobacter pylori in Mongolian gerbils colonizes a very distinct topology in the gastric mucous layer, obviously providing optimal conditions for long-term survival. Further research activities focused on H. pylori ammonia and metal metabolism as well as on bacterial stress defence mechanisms. Differential expression of approximately 7% of the bacterial genome was found at low pH suggesting that H. pylori has evolved a multitude of acid-adaptive mechanisms. VacA was shown to interrupt phagosome maturation in macrophage cell lines as well as to modulate and interfere with T lymphocyte immunological functions. Gastric mucosa as well as the H. pylori -infected epithelial cell line AGS strongly express IL-8 receptor A and B, which might contribute to the augmentation of the inflammatory response. Accumulating evidence implicates genetic variation in the inflammatory response to H. pylori in the etiology of the increased risk of gastric cancer after H. pylori infection. The chronic imbalance between apoptosis and cell proliferation is the first step of gastric carcinogenesis. In this regard, it was demonstrated that coexpression of two H. pylori proteins, CagA and HspB, in AGS cells, caused an increase in E2F transcription factor, cyclin D3, and phosphorylated retinoblastoma protein. Taken together, we now have a better understanding of the role of different virulence factors of H. pylori. There is still a lot to be learned, but the promising discoveries summarized here, demonstrate that the investigation of the bacterial survival strategies will give novel insights into pathogenesis and disease development. [source] The Migration,Development Nexus: Evidence and Policy OptionsINTERNATIONAL MIGRATION, Issue 5 2002Ninna Nyberg, Sørensen Migration and development are linked in many ways , through the livelihood and survival strategies of individuals, households, and communities; through large and often well,targeted remittances; through investments and advocacy by migrants, refugees, diasporas and their transnational communities; and through international mobility associated with global integration, inequality, and insecurity. Until now, migration and development have constituted separate policy fields. Differing policy approaches that hinder national coordination and international cooperation mark these fields. For migration authorities, the control of migration flows to the European Union and other OECD countries are a high priority issue, as is the integration of migrants into the labour market and wider society. On the other hand, development agencies may fear that the development policy objectives are jeopardized if migration is taken into consideration. Can long,term goals of global poverty reduction be achieved if short,term migration policy interests are to be met? Can partnership with developing countries be real if preventing further migration is the principal European migration policy goal? While there may be good reasons to keep some policies separate, conflicting policies are costly and counter,productive. More importantly, there is unused potential in mutually supportive policies, that is, the constructive use of activities and interventions that are common to both fields and which may have positive effects on poverty reduction, development, prevention of violent conflicts, and international mobility. This paper focuses on positive dimensions and possibilities in the migration,development nexus. It highlights the links between migration, development, and conflict from the premise that to align policies on migration and development, migrant and refugee diasporas must be acknowledged as a development resource. [source] Mothering in Public: A Meta-Synthesis of Homeless Women With Children Living in SheltersJOURNAL FOR SPECIALISTS IN PEDIATRIC NURSING, Issue 4 2003MPHArticle first published online: 24 AUG 200, Mikki Meadows-Oliver MSN ISSUES AND PURPOSE The purpose of this paper is to synthesize the current qualitative literature on homeless women with children living in shelters. METHODS Eighteen qualitative studies on homeless women with children living in shelters were included in the synthesis. The meta-synthesis was conducted using the meta-ethnographic approach of Noblit and Hare (1988). RESULTS Six reciprocal translations (themes) of homeless mothers caring for their children in shelters emerged: On becoming homeless, protective mothering, loss, stressed and depressed, survival strategies, and strategies for resolution. PRACTICE IMPLICATIONS The results may be used by healthcare workers as a framework for developing intervention strategies directed toward helping mothers find new solutions to dealing with shelter living and innovative ways to resolve their homelessness. [source] Searching for wages and mothering from Afar: The case of Honduran transnational familiesJOURNAL OF MARRIAGE AND FAMILY, Issue 5 2004Leah Schmalzbauer This article draws on data from a 2-year two-country study that included 157 people to explore the survival strategies of poor Honduran transnational families. I argue that transnational families, defined as those divided between two nation-states who have maintained close ties, depend on a cross-border division of labor in which productive labor occurs in the host country and reproductive labor in the home country. This article bridges the literatures on transnationalism and families. The transnationalism literature tends to focus on macro processes, whereas the literature on families assumes proximity. This research helps fill the gap in both literatures, exposing the ways in which processes of economic globalization have radically altered family form and function. [source] PARASITISM OF PHOTOSYNTHETIC DINOFLAGELLATES BY THREE STRAINS OF AMOEBOPHRYA (DINOPHYTA): PARASITE SURVIVAL, INFECTIVITY, GENERATION TIME, AND HOST SPECIFICITY1JOURNAL OF PHYCOLOGY, Issue 3 2002D. Wayne Coats Amoebophrya ceratii (Koeppen) Cachon is an obligate parasite of dinoflagellates and may represent a species complex. However, little is known about the biology and host range of different strains of Amoebophrya Cachon. Here, we determined parasite generation time and dinospore infectivity, survival, and ability to infect nonprimary hosts for strains of Amoebophrya from Akashiwo sanguinea (Hirasaka) G. Hansen et Moestrup, Gymnodinium instriatum (Freudenthal et Lee) Coats comb. nov., and Karlodinium micrum (Leadbeater et Dodge) J. Larsen. Akashiwo sanguinea was readily infected, with parasite prevalence reaching 100% in dinospore:host inoculations above a 10:1 ratio. Parasitism also approached 100% in G. instriatum, but only when inoculations exceeded a 40:1 ratio. Karlodinium micrum appeared partially resistant to infection, as parasite prevalence saturated at 92%. Parasite generation time differed markedly among Amoebophrya strains. Survival and infectivity of dinospores decreased over time, with strains from G. instriatum and A. sanguinea unable to initiate infections after 2 and 5 days, respectively. By contrast, dinospores from Amoebophrya parasitizing K. micrum remained infective for up to 11 days. Akashiwo sanguinea and G. instriatum were not infected when exposed to dinospores from nonprimary Amoebophrya strains. Karlodinium micrum, however, was attacked by dinospores of Amoebophrya from the other two host species, but infections failed to reach maturity. Observed differences in host,parasite biology support the hypothesis that Amoebophrya ceratii represents a complex of host-specific species. Results also suggest that Amoebophrya strains have evolved somewhat divergent survival strategies that may encompass sexuality, heterotrophy during the "free-living" dinospore stage, and dormancy. [source] Dialogic inquiry in life science conversations of family groups in a museumJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 2 2003Doris Ash This research illustrates the efficacy of a new approach for collecting and analyzing family conversational data at museums and other informal settings. This article offers a detailed examination of a small data set (three families) that informs a larger body of work that focuses on conversation as methodology. The dialogic content of this work centers on biological themes, specifically adaptation. The biological principle becomes visible when families talk about survival strategies such as breeding or protection from predators. These themes arise from both the family members and the museum exhibit. This study also analyzes the inquiry skills families use as they make sense of science content. I assume that children and adults offer different interest areas or expertise for dialogic negotiation and that family members use inquiry skills in dialogue to explore matters of importance. This analysis offers educators methodological tools for investigating families' scientific sense-making in informal settings. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 138,162, 2003 [source] Hepatitis viruses: live and let dieLIVER INTERNATIONAL, Issue 3 2007K. Herzer Abstract Viral hepatitis is a diffuse inflammatory reaction of the liver caused by hepatotropic viruses. Among the hepatitis viruses, only hepatitis B virus and hepatitis C virus are able to persist in the host and cause chronic hepatitis. In the course of persistent infection, inflammation forms the pathogenetic basis of chronic hepatitis that can lead to nodular fibrosis, which can progress to cirrhosis and, eventually, hepatocellular carcinoma (HCC). Of the different antiviral defense systems employed by the host, apoptosis significantly contributes to the prevention of viral replication, dissemination, and persistence. Pathomorphologic studies have shown acidophilic bodies and hepatocyte dropout, features that are compatible with apoptosis. The number of hepatocytes showing features of apoptosis in patients with chronic hepatitis B and C was found to be higher than in healthy subjects, indicating that apoptosis is involved in the pathogenesis of these diseases. There are various data suggesting that hepatitis B and C viral proteins may modulate apoptosis. Vice versa, mechanisms of apoptosis inhibition might represent central survival strategies employed by the virus which, in the end, may contribute to HCC development. While the expression and retention of viral proteins in hepatocytes may influence the severity and progression of liver disease, the mechanisms of liver injury in viral hepatitis are defined to be due not only to the direct cytopathic effects of viruses, but also to the host immune response to viral proteins expressed by infected hepatocytes. However, the exact role of these observations in relation to pathogenesis remains to be established. The mechanism and systems are complex. This report aims to provide an overview and intends to cite only a small number of pertinent references. [source] Memory, Forgetting, and Economic Crisis:MEDICAL ANTHROPOLOGY QUARTERLY, Issue 1 2010Drug Use, Social Fragmentation in an Argentine Shantytown Closely linked to the increase in psychotropic pill consumption, forgetting and remembering emerged from devastated social scenarios as a new local idiom among poor youth in the late 1990s and the new millennium. Drawing on ethnographic fieldwork carried out during the years of the deepest economic crisis in Argentina (2001,03), I argue that psychotropic pill consumption is associated with not only deteriorating economic conditions but also changes in the quality and price of cocaine, and in the scarcity and subsequent change of status of medications during the economic breakdown. Taking into account developments in the field of memory studies, I examine the relationship among political economy, social memory work, and changing drug-use practices. Regarding memory as a social practice, I argue that the growth of psychotropic pill consumption in the late 1990s can be understood through the interplay of Paul Ricoeur's notions regarding different kinds and levels of forgetting. By analyzing changing survival strategies, social network dismantlement, changing mortality patterns, and abusive police repression, I discuss how social fragmentation engendered by structural reforms has modified social memory work. [source] Strategy differences of two potato species in response to nitrogen starvation.PLANT CELL & ENVIRONMENT, Issue 7 2000Do plants have a genetic switch for nitrogen signalling? ABSTRACT Survival responses to nitrogen starvation are well known in micro-organisms but little studied in plants. To construct a framework for study of the plant responses, we investigated the strategy differences of tubers from two closely related potato species. Solanum tuberosum conserves tuber nitrogen by inhibiting shoot growth, but S. phureja mobilizes tuber nitrogen to grow shoots, flowers and seeds. Genetic analysis of progeny from S. phureja,haploid S. tuberosum crosses uncovered segregation of a single dominant gene for the S. tuberosum inhibition strategy. Within S. tuberosum, haploid progeny closely resembled their tetraploid parents, suggesting strong genetic control of the inhibition. Growth of the inhibited shoots was proportional to sub-optimal levels of added nitrate, and was triggered by exogenous gibberellic acid (GA3). These observations support the notion that potato plants can closely tie shoot growth to ambient nitrogen levels , probably by a root,shoot nitrogen signal transduction pathway, and that this can be overridden by emergency mobilization of nitrogen reserves, perhaps by GA signalling from the tuber. Furthermore, genes for such developmental switches can be identified by classical genetic analysis of closely related species, such as S. tuberosum and S. phureja, that exhibit opposite survival strategies. [source] Environmental factors and survival strategies of annual plant species in the Negev Desert, IsraelPLANT SPECIES BIOLOGY, Issue 2 2000Yitzchak Gutterman Abstract Several environmental factors have pronounced influences on the complementary sets of survival strategies, at different stages of the plant life cycle, of some of the most common annual plants in the Negev Desert, Israel. Plasticity of seed germination may spread germination over time and thus reduce the risk to species survival. This plasticity may be affected by day length during seed development and maturation and by position of seeds on mother plants. Post-seed maturation dry storage temperatures may affect the duration of after-ripening. The tiny, dust-like seeds produced by some plants that are dispersed by wind after maturation may escape massive seed predation and remain in large seed banks in the soil. Seeds of other species are protected in lignified structures in aerial seed banks on dead, dry, lignified mother plants. Seed dispersal strategies from these aerial seed banks by rain may also prevent massive seed collection by animals. The ,cautious' or ,opportunistic' germination strategy and seedling drought tolerance may increase seedling survival in many of the plant species under the unpredictable amounts and distribution of rain in these desert areas. Factors such as amount of rain, temperature, relative humidity, time of the beginning of soil wetting (day or night), seed size and history and the depth of seeds in the soil may affect germination percentages. Day length and soil water content during plant development may have a pronounced influence on plant age at first flowering, seed yield and plant life span. [source] Psychological well being and quality of life in ovarian cancer survivorsCANCER, Issue 5 2003Betty Ferrell Ph.D. Abstract BACKGROUND This report offers a unique analysis of the psychological distress associated with ovarian cancer in a review of natural correspondence between ovarian cancer survivors and an ovarian cancer newsletter. METHODS A review of 21,806 letters, cards, and e-mails reflecting correspondence from January 1994 to December 2000 between ovarian cancer survivors and the founding editor of Conversations!: The International Newsletter for those Fighting Ovarian Cancer was performed using ethnographic qualitative research methods. Statements related to the impact of disease were bracketed and coded within physical, psychological, social, and spiritual domains according to the City of Hope Quality of Life Ovarian Cancer instrument. Statements that reflected psychological well being were then evaluated with respect to the disease trajectory (i.e., diagnosis, treatment, remission, recurrence, and advanced disease/end of life). RESULTS A total of 1282 communications were identified that pertained to psychological well being. Findings based on major themes derived from the analysis included descriptions of stressors associated with disease status. Significant stressors were identified within all phases of diagnosis, treatment, remission, and recurrence. Women described both positive and negative effects of disease and frequently demonstrated resourcefulness and perseverance by sharing coping mechanisms and survival strategies. CONCLUSIONS The natural correspondence from women with ovarian cancer provided a rare opportunity to capture the psychological concerns of women throughout all stages of the cancer trajectory. Health care professionals' awareness of the common psychological stressors throughout the ovarian cancer trajectory may allow them to identify more readily the needs for support, leading to improvement in overall quality of life. Cancer 2003;98:1061,71. © 2003 American Cancer Society. DOI 10.1002/cncr.11291 [source] Mycobacterial survival strategies in the phagosome: defence against host stressesCELLULAR MICROBIOLOGY, Issue 8 2009Sabine Ehrt Summary Infections with Mycobacterium tuberculosis remain a major cause of disease and death in humans. Among the factors that contribute to M. tuberculosis's success as a pathogen is its ability to withstand potentially bactericidal host defences and to resist elimination by an activated immune system. This resistance to killing by the host is in part due to the low permeability of the mycobacterial cell envelope for many toxic molecules. In addition, it depends upon the detoxification of reactive oxygen and reactive nitrogen molecules produced by the host, the repair of the damage these molecules cause and maintenance of a neutral intrabacterial pH within acidic environments. The latter three mechanisms are the focus of this review. [source] 3135: Modulation of apoptotic signaling pathways to promote survival of endothelial cells by gene therapyACTA OPHTHALMOLOGICA, Issue 2010T FUCHSLUGER Purpose Corneal transplantation is the most common transplantation worldwide. Surgeons and eye banks face major problems: (1) shortage of tissue in aging populations, (2) loss of high-quality tissue due to cell loss during storage, (3) graft failure. It has been demonstrated that EC loss is mediated by the cells' intrinsic death machinery resulting in apoptosis. Identification of survival strategies could raise the availability of tissue, with a significant impact on transplantation by lowering graft rejection rate. The purpose of this study different apoptotic pathways and to determine the protective effect of the anti-apoptotic proteins bcl-xL and p35. Methods Intrinsic (mitochondria-mediated) and extrinsic (ligand-mediated) apoptotic pathways were selectively activated to provoke apoptosis of murine and human corneal endothelial cells suspensions and corneas. Gene transfer of bcl-xL or p35 was accomplished, survival of EC was determined by flow cytometry and laser scanning microscopy. Results Interestingly, we were able to determine distinct differences in cell survival enhancement depending on the type of overexpressed protein. Whereas uninfected controls showed significant EC death, gene-therapeutically treated EC demonstrated significantly increased cell survival. We will present data on the efficacy of certain anti-apoptotic proteins in select pathways. Conclusion Exploring inhibitory strategies of EC death can lead to clinically relevant survival strategies with significant impact on corneal grafting. [source] Leishmania donovani infection down-regulates TLR2-stimulated IL-12p40 and activates IL-10 in cells of macrophage/monocytic lineage by modulating MAPK pathways through a contact-dependent mechanismCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2008Dinesh Chandra Summary The failure of Leishmania, an intracellular pathogen, to stimulate a pro-inflammatory response following entry into macrophages has been well reported. This occurs in spite of the fact that ligands for the toll-like receptors (TLR) have been recently shown on the parasite surface and their role in disease protection well documented. The outcome of infection in leishmaniasis is determined by the Th1 versus Th2 nature of the effector response and the generation of IL-12 and IL-10 by the infected macrophages is important for this decision. We evaluated the effect of L. donovani infection of monocytes (cell line THP-1, and monocytes derived from human peripheral blood) on Pam3cys (TLR2 ligand) and lipopolysaccharide (TLR4 ligand) stimulated production of IL-12p40 and IL-10. L. donovani infection caused suppression of TLR2 and TLR4-stimulated IL-12p40, with an increase in IL-10 production. Parasites also modulated the TLR2-stimulated mitogen-activated protein kinase (MAPK) pathway by suppressing MAPK P38 phosphorylation and activating extracellular regulated kinase (ERK)1/2 phosphorylation. These effects could be reversed either by using a MAPK P38 activator, anisomycin, or ERK1/2 inhibitor, U0126. L. donovani caused modulation of TLR2-stimulated MAPK pathways in a contact-dependent mechanism. In addition parasite structural integrity but not viability was required for suppression of TLR2-stimulated IL-12p40 and activation of IL-10. These observations suggest that L. donovani has evolved survival strategies that subvert the pro-inflammatory response generated through TLRs. [source] The fig wax scale Ceroplastes rusci (Linnaeus) (Homoptera: Coccidae) in south-east Vietnam: Pest status, life history and biocontrol trials with Eublemma amabilis Moore (Lepidoptera: Noctuidae)ENTOMOLOGICAL RESEARCH, Issue 4 2006Nga Thi VU Abstract The fig wax scale Ceroplastes rusci (Linnaeus) is a serious pest of fruit trees in many countries. In the present study we investigated the extent of C. rusci infestation and the range of host species, particularly in fruit orchards, in south-east Vietnam. Captive populations of C. rusci were established to record life history parameters and to investigate the efficacy of an endemic predacious moth, Eublemma amabilis Moore, as a potential biocontrol agent. Heavy infestation of C. rusci (up to 100%) was recorded in soursop and other fruit orchards, and the culturally important Hoa Mai flower was also affected. Captive breeding trials found E. amabilis to be an efficient predator of C. rusci, but an unusual hyperactive trait in early instars of E. amabilis resulted in lower than expected survival rates. The implications of this trait in terms of the laboratory environment, augmentative release protocols and as a survival strategy are discussed. [source] The obligate aerobic actinomycete Streptomyces coelicolor A3(2) survives extended periods of anaerobic stressENVIRONMENTAL MICROBIOLOGY, Issue 12 2007Geertje Van Keulen Summary The actinomycete Streptomyces coelicolor is an obligate aerobe that is found in soil and aqueous habitats. The levels of oxygen in these environments can vary considerably, which raises the question of how these bacteria survive during periods of anaerobiosis. Although S. coelicolor cannot grow in the complete absence of oxygen, we demonstrate here that it is capable of microaerobic growth and maintaining viability through several weeks of strict anaerobiosis. Both resting and germinated spores are able to survive abrupt exposure to anaerobiosis, which contrasts the situation with Mycobacterium species where gradual oxygen depletion is required to establish a latent state in which the bacterium is able to survive extended periods of anaerobiosis. Growth of S. coelicolor resumes immediately upon re-introduction of oxygen. Taken together these findings indicate that survival is not restricted to spores and suggest that the bacterium has evolved a mechanism to maintain viability and a membrane potential in the hyphal state. Furthermore, although we demonstrate that several members of the genus also survive long periods of anaerobic stress, one species, Streptomyces avermitilis, does not have this capacity and might represent a naturally occurring variant that is unable to adopt this survival strategy. [source] Detergent-induced cell aggregation in subpopulations of Pseudomonas aeruginosa as a preadaptive survival strategyENVIRONMENTAL MICROBIOLOGY, Issue 9 2007Janosch Klebensberger Summary During growth of Pseudomonas aeruginosa strain PAO1 with the toxic detergent SDS, a part of the population actively formed macroscopic cell aggregates while the other part grew as freely suspended cells. The physiological function of aggregation for growth with SDS was investigated. Three mutants growing with SDS without aggregation were isolated: the spontaneous mutant strain N and two mutants with transposon insertions in the psl operon for exopolysaccharide synthesis. SDS-induced aggregation in strain N but not in a pslJ mutant was restored by complementation with two genes encoding diguanylate cyclases responsible for synthesis of cyclic-di-guanosine monophosphate (c-di-GMP). By expressing a c-di-GMP-specific phosphodiesterase SDS-induced aggregation of strain PAO1 was reduced. Upon exposure to SDS in the presence of the uncoupler carbonyl cyanide chlorophenylhydrazone, the aggregating strains had ca. 500-fold higher survival rates than the non-aggregating strains. Co-incubation experiments revealed that strain N could integrate into aggregates of strain PAO1 and thereby increase its survival rate more than 1000-fold. These results showed that SDS-induced aggregation involved c-di-GMP signalling with the psl operon as a possible target. Cell aggregation could serve as a pre-adaptive strategy ensuring survival and growth of P. aeruginosa populations in environments with multiple toxic chemicals. [source] RECENT AND FUTURE MANAGEMENT CHANGES IN LOCAL GOVERNMENT: CONTINUING FOCUS ON RATIONALITY AND EFFICIENCY?FINANCIAL ACCOUNTABILITY & MANAGEMENT, Issue 1 2008Henk J. Ter Bogt Dutch municipalities and provinces have recently introduced many changes relating to management control. This paper explores the role of economic and social rationality in the introduction of reforms, and the nature of possible future reforms. Based on interviews with politicians and professional managers and on documents, the paper examines experiences with recent management changes. In addition, it discusses ,change initiating factors'. Budget cuts and trends seem to be such change initiating factors. However, particularly more demanding citizens, increases in voters' volatility and politicians' uncertainty seemed to initiate changes. The paper speculates that in the near future, too, it could be a rational survival strategy for politicians and managers to focus on initiatives that are intended to enhance performance and efficiency. [source] Carrying capacity and survival strategy for the Pacific bluefin tuna, Thunnus orientalis, in the Western PacificFISHERIES OCEANOGRAPHY, Issue 2 2006YASUO MATSUKAWA Abstract The carrying capacity for the Pacific bluefin tuna at each life stage is estimated and its survival strategy is examined numerically, using a new method to define the hypothetical capacity, the standard population, and the search volumes that are necessary and are feasible for the tuna. The carrying capacity for the adult is estimated at 1,2 × 106 individuals, which corresponds with 5,10% of the hypothetical capacity and is comparable with the maximum levels of the southern and the Atlantic bluefin tuna populations. It is hypothesized semiquantitatively that the migration at each life stage and the remarkable decrement of growth at 120 days and about 40 cm occur as an evolutionary response to population excess over the carrying capacity. It is also hypothesized semiquantitatively that the early larvae have minimal food available in the Subtropical Water and develop the predatory morphology, high growth rate, and high mobility, however, at the expense of a high mortality as an evolutionary response to the tuna spawning in the Subtropical Water. This method may be an available tool to not only investigate the carrying capacity and survival strategy of a specific fish species, but also predict when and in how much abundance the fish species occurs in a specific area of its habitat. [source] The balance between photosynthesis and grazing in Antarctic mixotrophic cryptophytes during summerFRESHWATER BIOLOGY, Issue 11 2002William Marshall SUMMARY 1. Grazing and photosynthetic contributions to the carbon balance of planktonic, mixotrophic cryptophytes in Lakes Fryxell and Hoare in the Taylor Valley, Antarctica were measured during November and December 2000. 2. The cryptophytes never became entirely photosynthetic, although carbon derived from grazing decreased in December. Individual grazing rates ranged between 5.28 and 10.08 bacteria cell,1 day,1 in Lake Fryxell and 0.36,11.76 bacteria cell,1 day,1 in Lake Hoare. Grazing rates varied temporally and with depth in the water column. In Lake Fryxell, which is a meromictic lake, highest grazing occurred just above the chemocline. Individual photosynthetic rates ranged from 0.23 to 1.35 pg C cell,1 h,1 in Lake Fryxell and 0.074 to 1.08 pg C cell,1 h,1 in Lake Hoare. 3. Carbon acquisition by the cryptophyte community gained through grazing ranged between 8 and 31% during November in Lake Fryxell, dropping to between 2 and 24% in December. In Lake Hoare grazing contributed 12,21% of the community carbon budget in November and 1,28% in December. Around 4% of the carbon acquired from grazing and photosynthesis was remineralised through respiration. 4. Mixotrophy is probably a major survival strategy for cryptophytes in the extreme lakes of the Dry Valleys, because perennial ice-cover severely limits light penetration to the water column, whereas these phytoflagellates are not normally mixotrophic in lower latitude lakes. The evidence suggests that mixotrophy may be a mechanism for supplementing the carbon budget, as well as a means of acquiring nutrients for growth. [source] Growth of the tufted-tailed ratINTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 4 2007Vololomboahangy R. RANDRIANJAFY Abstract Eliurus myoxinus (Rodentia: Nesomyidae, Nesomyinae) is one of the four species of endemic Malagasy rodents known to exist in the Ankarafantsika National Park, northwestern Madagascar. In order to study growth parameters and to determine at which age E. myoxinus commences breeding, we used two different techniques: captive breeding and a capture-mark-release field program in the species' natural habitat. The data collected on the breeding of E. myoxinus in captivity demonstrated that females can give birth to a litter of up to four pups, with up to four litters per calendar year. Reproduction of E. myoxinus was more likely to be continuous in captivity than under natural habitat conditions. If parturition failed, then post-partum mating occurred. Pups had a rapid linear growth phase from birth until 1 month of age. Between 1.5 and 2 months of age, the growth rate continued to increase, but then decreased at around the time of weaning, which occurred by 3.5 months of age. The successive maximum method of age determination showed that individuals at the "young" stage had an average body length of 90 mm and a weight of 30 g and were between 1.5 and 2 months old. The greatest variation in measurements of juveniles occurred at the age of 3.5 months. At this stage, sub-adults resembled adults but their external genitalia were not well developed. Individuals were classified as adults if they had reached a body length of 110 mm and a body weight of 40 g. This occurred at more than 4.5 months of age when the animals were generally reproductively active. The Vo n Bertalanffy method indicated that individuals reach the adult stage by 6 to 7 months. Males grew more rapidly than females, reaching adulthood by 5.5 months of age, whereas females only reached adulthood several weeks later. This species is polygamous. The sex ratio of pups at birth favored females by approximately 3:1. The higher proportion of female pups at birth may represent a survival strategy of this species, possibly associated with ecological conditions. [source] ,Step back in time and live the legend': experiential marketing and the heritage sectorINTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 2 2007Debra Leighton This paper investigates experiential marketing as a potential survival strategy for cultural heritage attractions competing in the leisure and tourism marketplace. The paper explores the nature and scope of the heritage industry, heritage as a consumption-based experience and the evidence of adoption of the experiential paradigm by a number of sites and attractions. A content analysis (Krippendorf, 1980 cited in Easterby-Smith et al., 2002) of promotional leaflets and websites and a case study provide the analytical basis for this evaluation and the paper concludes by proposing an indicative framework for experiential marketing in this sector. Copyright © 2006 John Wiley & Sons, Ltd. [source] Role of hydrogen peroxide during the interaction between the hemibiotrophic fungal pathogen Septoria tritici and wheatNEW PHYTOLOGIST, Issue 3 2007Nandini P. Shetty Summary ,,Hydrogen peroxide (H2O2) is reported to inhibit biotrophic but benefit necrotrophic pathogens. Infection by necrotrophs can result in a massive accumulation of H2O2 in hosts. Little is known of how pathogens with both growth types are affected (hemibiotrophs). The hemibiotroph, Septoria tritici, infecting wheat (Triticum aestivum) is inhibited by H2O2 during the biotrophic phase, but a large H2O2 accumulation occurs in the host during reproduction. ,,Here, we infiltrated catalase, H2O2 or water into wheat during the biotrophic or the necrotrophic phase of S. tritici and studied the effect of infection on host physiology to get an understanding of the survival strategy of the pathogen. ,,H2O2 removal by catalase at both early and late stages made plants more susceptible, whereas H2O2 made them more resistant. H2O2 is harmful to S. tritici throughout its life cycle, but it can be tolerated. ,,The late accumulation of H2O2 is unlikely to result from down-regulation of photosynthesis, but probably originates from damage to the peroxisomes during the general tissue collapse, which is accompanied by release of soluble sugars in a susceptible cultivar. [source] Proteolysis during long-term glucose starvation in Staphylococcus aureus COLPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 19 2009Stephan Michalik Abstract A combination of pulse-chase experiments and 2-D PAGE revealed that protein degradation appears to play a crucial role for the cell physiology of Staphylococcus aureus COL during extended periods of glucose starvation. The synthesis rate of virtually all cytosolic and radioactively labeled proteins from growing cells seemed dramatically reduced in the first 3.5,h of glucose starvation. The stability of proteins synthesized in growing cells was monitored by a pulse-chase approach on a proteome wide scale. Especially, enzymes involved in nucleic acid and amino acid biosyntheses, energy metabolism and biosynthesis of cofactors were found rather rapidly degraded within the onset of the stationary phase, whereas the majority of glycolytic and tricarboxylic acid cycle enzymes remained more stable. Furthermore, single enzymes of biosynthetic pathways were differentially degraded. A metabolite analysis revealed that glucose completely depleted from the medium in the transient phase, and amino acids such as alanine and glycine were taken up by the cells in the stationary phase. We suggest that vegetative proteins no longer required in non-growing cells and thus no longer protected by integration into functional complexes were degraded. Proteolysis of putative non-substrate-bound or "unemployed" proteins appears to be a characteristic feature of S. aureus in order to access nutrients as an important survival strategy under starvation conditions. [source] Fallback foods of temperate-living primates: A case study on snub-nosed monkeysAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Cyril C. Grueter Abstract Only a few primate species thrive in temperate regions characterized by relatively low temperature, low rainfall, low species diversity, high elevation, and especially an extended season of food scarcity during which they suffer from dietary stress. We present data of a case study of dietary strategies and fallback foods in snub-nosed monkeys (Rhinopithecus bieti) in the Samage Forest, Northwest Yunnan, PRC. The snub-nosed monkeys adjusted intake of plant food items corresponding with changes in the phenology of deciduous trees in the forest and specifically showed a strong preference for young leaves in spring. A non-plant food, lichens (Parmeliaceae), featured prominently in the diet throughout the year (annual representation in the diet was about 67%) and became the dominant food item in winter when palatable plant resources were scarce. Additional highly sought winter foods were frost-resistant fruits and winter buds of deciduous hardwoods. The snub-nosed monkeys' choice of lichens as a staple fallback food is likely because of their spatiotemporal consistency in occurrence, nutritional and energetic properties, and the ease with which they can be harvested. Using lichens is a way to mediate effects of seasonal dearth in palatable plant foods and ultimately a key survival strategy. The snub-nosed monkeys' fallback strategy affects various aspects of their biology, e.g., two- and three-dimensional range use and social organization. The higher abundance of lichens at higher altitudes explains the monkeys' tendency to occupy relatively high altitudes in winter despite the prevailing cold. As to social organization, the wide temporal and spatial availability of lichens strongly reduces the ecological costs of grouping, thus allowing for the formation of "super-groups." Usnea lichens, the snub-nosed monkeys' primary dietary component, are known to be highly susceptible to human-induced environmental changes such as air pollution, and a decline of this critical resource base could have devastating effects on the last remaining populations. Within the order Primates, lichenivory is a rare strategy and only found in a few species or populations inhabiting montane areas, i.e., Macaca sylvanus, Colobus angolensis, and Rhinopithecus roxellana. Other temperate-dwelling primates rely mainly on buds and bark as winter fallback foods. Am J Phys Anthropol 140:700,715, 2009. © 2009 Wiley-Liss, Inc. [source] Informal Self-Employment in Developing Countries: Entrepreneurship or Survivalist Strategy?ANALYSES OF SOCIAL ISSUES & PUBLIC POLICY, Issue 1 2009Some Implications for Public Policy A central debate around labor market informality, which has enormous implications for the design and implementation of public policy, relates to the nature of informal employment. Is informal employment and, in particular, informal self-employment, a symptom and, at the same time, a reproductive factor of precariousness and inequality, as well as social and individual poverty? Or is it, on the contrary, a space of individual and social action that reflects economic initiative and business potential which, if channeled and fostered properly, could contribute to social and economic development and, consequently, to the reduction of inequality and poverty? In this article, the findings of the 2005 edition of the Mexican version of the World Value Survey,concerning relevant values and attitudes of informal participants in the labor force in Mexico,are used to assess whether informal self-employment is a reflection of incipient entrepreneurship and individual choice or, rather, a survival strategy forced on individuals by their precarious circumstances. This article explores the public policy implications of the results obtained. 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