371 resultados para Svensson, Ingeborg
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Este artículo estudia la credibilidad del régimen cambiario de bandas de fluctuación crecientes a tasa constante de Venezuela durante el periodo julio de 1996-febrero de 2002. Mostramos que los análisis de credibilidad aplicados a zonas objetivo, introduciendo algunas modificaciones, también pueden utilizarse para estudiar la credibilidad de sistemas cambiarios de bandas de fluctuación crecientes a tasa constante. En este trabajo aplicamos tanto el denominado test de credibilidad de Svensson como el método de ajuste de la deriva. Con ambos métodos obtenemos resultados similares en cuanto al alto grado de credibilidad del sistema durante el periodo analizado.
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We study the role of natural resource windfalls in explaining the efficiency of public expenditures. Using a rich dataset of expenditures and public good provision for 1,836 municipalities in Peru for period 2001-2010, we estimate a non-monotonic relationship between the efficiency of public good provision and the level of natural resource transfers. Local governments that were extremely favored by the boom of mineral prices were more efficient in using fiscal windfalls whereas those benefited with modest transfers were more inefficient. These results can be explained by the increase in political competition associated with the boom. However, the fact that increases in efficiency were related to reductions in public good provision casts doubts about the beneficial effects of political competition in promoting efficiency.
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The combination of virulence gene and antimicrobial resistance gene typing using DNA arrays is a recently developed genomics-based approach to bacterial molecular epidemiology. We have now applied this technology to 523 Salmonella enterica subsp. enterica strains collected from various host sources and public health and veterinary institutes across nine European countries. The strain set included the five predominant Salmonella serovars isolated in Europe (Enteritidis, Typhimurium, Infantis, Virchow, and Hadar). Initially, these strains were screened for 10 potential virulence factors (avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, and bcfC) by polymerase chain reaction. The results indicated that only 14 profiles comprising these genes (virulotypes) were observed throughout Europe. Moreover, most of these virulotypes were restricted to only one (n = 9) or two (n = 4) serovars. The data also indicated that the virulotype did not vary significantly with host source or geographical location. Subsequently, a representative subset of 77 strains was investigated using a microarray designed to detect 102 virulence and 49 resistance determinants. The results confirmed and extended the previous observations using the virulo-polymerase chain reaction screen. Strains belonging to the same serovar grouped together, indicating that the broader virulence-associated gene complement corresponded with the serovar. There were, however, some differences in the virulence gene profiles between strains belonging to an individual serovar. This variation occurred primarily within those virulence genes that were prophage encoded, in fimbrial clusters or in the virulence plasmid. It seems likely that such changes enable Salmonella to adapt to different environmental conditions, which might be reflected in serovar-specific ecology. In this strain subset a number of resistance genes were detected and were serovar restricted to a varying degree. Once again the profiles of those genes encoding resistance were similar or the same for each serovar in all hosts and countries investigated.
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Whole-genome sequencing offers new insights into the evolution of bacterial pathogens and the etiology of bacterial disease. Staph- ylococcus aureus is a major cause of bacteria-associated mortality and invasive disease and is carried asymptomatically by 27% of adults. Eighty percent of bacteremias match the carried strain. How- ever, the role of evolutionary change in the pathogen during the progression from carriage to disease is incompletely understood. Here we use high-throughput genome sequencing to discover the genetic changes that accompany the transition from nasal carriage to fatal bloodstream infection in an individual colonized with meth- icillin-sensitive S. aureus. We found a single, cohesive population exhibiting a repertoire of 30 single-nucleotide polymorphisms and four insertion/deletion variants. Mutations accumulated at a steady rate over a 13-mo period, except for a cluster of mutations preceding the transition to disease. Although bloodstream bacteria differed by just eight mutations from the original nasally carried bacteria, half of those mutations caused truncation of proteins, including a prema- ture stop codon in an AraC-family transcriptional regulator that has been implicated in pathogenicity. Comparison with evolution in two asymptomatic carriers supported the conclusion that clusters of pro- tein-truncating mutations are highly unusual. Our results demon- strate that bacterial diversity in vivo is limited but nonetheless detectable by whole-genome sequencing, enabling the study of evolutionary dynamics within the host. Regulatory or structural changes that occur during carriage may be functionally important for pathogenesis; therefore identifying those changes is a crucial step in understanding the biological causes of invasive bacterial disease.
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Background Staphylococcus aureus is a major cause of healthcare associated mortality, but like many important bacterial pathogens, it is a common constituent of the normal human body flora. Around a third of healthy adults are carriers. Recent evidence suggests that evolution of S. aureus during nasal carriage may be associated with progression to invasive disease. However, a more detailed understanding of within-host evolution under natural conditions is required to appreciate the evolutionary and mechanistic reasons why commensal bacteria such as S. aureus cause disease. Therefore we examined in detail the evolutionary dynamics of normal, asymptomatic carriage. Sequencing a total of 131 genomes across 13 singly colonized hosts using the Illumina platform, we investigated diversity, selection, population dynamics and transmission during the short-term evolution of S. aureus. Principal Findings We characterized the processes by which the raw material for evolution is generated: micro-mutation (point mutation and small insertions/deletions), macro-mutation (large insertions/deletions) and the loss or acquisition of mobile elements (plasmids and bacteriophages). Through an analysis of synonymous, non-synonymous and intergenic mutations we discovered a fitness landscape dominated by purifying selection, with rare examples of adaptive change in genes encoding surface-anchored proteins and an enterotoxin. We found evidence for dramatic, hundred-fold fluctuations in the size of the within-host population over time, which we related to the cycle of colonization and clearance. Using a newly-developed population genetics approach to detect recent transmission among hosts, we revealed evidence for recent transmission between some of our subjects, including a husband and wife both carrying populations of methicillin-resistant S. aureus (MRSA). Significance This investigation begins to paint a picture of the within-host evolution of an important bacterial pathogen during its prevailing natural state, asymptomatic carriage. These results also have wider significance as a benchmark for future systematic studies of evolution during invasive S. aureus disease.
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We present a new speleothem record of atmospheric Δ14C between 28 and 44 ka that offers considerable promise for resolving some of the uncertainty associated with existing radiocarbon calibration curves for this time period. The record is based on a comprehensive suite of AMS 14C ages, using new low-blank protocols, and U–Th ages using high precision MC-ICPMS procedures. Atmospheric Δ14C was calculated by correcting 14C ages with a constant dead carbon fraction (DCF) of 22.7 ± 5.9%, based on a comparison of stalagmite 14C ages with the IntCal04 (Reimer et al., 2004) calibration curve between 15 and 11 ka. The new Δ14C speleothem record shows similar structure and amplitude to that derived from Cariaco Basin foraminifera (Hughen et al., 2004, 2006), and the match is further improved if the latter is tied to the most recent Greenland ice core chronology (Svensson et al., 2008). These data are however in conflict with a previously published 14C data set for a stalagmite record from the Bahamas — GB-89-24-1 (Beck et al., 2001), which likely suffered from 14C analytical blank subtraction issues in the older part of the record. The new Bahamas speleothem ∆14C data do not show the extreme shifts between 44 and 40 ka reported in the previous study (Beck et al., 2001). Causes for the observed structure in derived atmospheric Δ14C variation based on the new speleothem data are investigated with a suite of simulations using an earth system model of intermediate complexity. Data-model comparison indicates that major fluctuations in atmospheric ∆14C during marine isotope stage 3 is primarily a function of changes in geomagnetic field intensity, although ocean–atmosphere system reorganisation also played a supporting role.
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Horizontal gene transfer is an important driver of bacterial evolution, but genetic exchange in the core genome of clonal species, including the major pathogen Staphylococcus aureus, is incompletely understood. Here we reveal widespread homologous recombination in S. aureus at the species level, in contrast to its near-complete absence between closely related strains. We discover a patchwork of hotspots and coldspots at fine scales falling against a backdrop of broad-scale trends in rate variation. Over megabases, homoplasy rates fluctuate 1.9-fold, peaking towards the origin-of-replication. Over kilobases, we find core recombination hotspots of up to 2.5-fold enrichment situated near fault lines in the genome associated with mobile elements. The strongest hotspots include regions flanking conjugative transposon ICE6013, the staphylococcal cassette chromosome (SCC) and genomic island νSaα. Mobile element-driven core genome transfer represents an opportunity for adaptation and challenges our understanding of the recombination landscape in predominantly clonal pathogens, with important implications for genotype–phenotype mapping.
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It is argued that existing polar prediction systems do not yet meet users’ needs; and possible ways forward in advancing prediction capacity in polar regions and beyond are outlined. The polar regions have been attracting more and more attention in recent years, fuelled by the perceptible impacts of anthropogenic climate change. Polar climate change provides new opportunities, such as shorter shipping routes between Europe and East Asia, but also new risks such as the potential for industrial accidents or emergencies in ice-covered seas. Here, it is argued that environmental prediction systems for the polar regions are less developed than elsewhere. There are many reasons for this situation, including the polar regions being (historically) lower priority, with less in situ observations, and with numerous local physical processes that are less well-represented by models. By contrasting the relative importance of different physical processes in polar and lower latitudes, the need for a dedicated polar prediction effort is illustrated. Research priorities are identified that will help to advance environmental polar prediction capabilities. Examples include an improvement of the polar observing system; the use of coupled atmosphere-sea ice-ocean models, even for short-term prediction; and insight into polar-lower latitude linkages and their role for forecasting. Given the enormity of some of the challenges ahead, in a harsh and remote environment such as the polar regions, it is argued that rapid progress will only be possible with a coordinated international effort. More specifically, it is proposed to hold a Year of Polar Prediction (YOPP) from mid-2017 to mid-2019 in which the international research and operational forecasting community will work together with stakeholders in a period of intensive observing, modelling, prediction, verification, user-engagement and educational activities.
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Syftet med denna litteraturstudie var att belysa hur massage kan påverka patientens besvär i samband med bröstcancer. Syftet var även att belysa dessa patienters upplevelse av massage. Genom att göra en litteraturstudie fick författarna en kunskapsöversikt inom detta område. Författarna har använt sig av databaserna Cinahl (EBSCO) och Medline (EBSCO), samt informationstjänsten Elin@Dalarna. 12 vetenskapliga artiklar ligger till grund för litteraturstudiens resultat. Resultaten visade på att olika typer av massage påverkade bland annat välbefinnandet, smärta och sömnen hos patienterna med bröstcancer, detta i positiv riktning. Massagen visade sig även ha effekt på upplevelsen av ångest, oro och depression. Volym av lymfödem har visat sig kunna minska efter massage. Patienterna i studierna uppgav att få massage upplevdes som en verklighetsflykt från obehaget som följer med cellgiftsbehandling. Författarna anser att massage kan vara en bra komplementär omvårdnadshandling för sjuksköterskor att erbjuda, informera om eller utföra på patienter med bröstcancer.
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Jag har i den här uppsatsen analyserat Baba Jaga je snijela jajes (2008) hybridlika struktur genom att göra en postmodernistisk analys. Under uppsatsens gång har jag läst och tolkat vad olika teoretiker har skrivit om postmoderna begrepp; såsom hybriditetsbegreppet, det ontologiska tvivlet samt även med att definiera myten och fiktionen. Jag har genom citat och analys gjort en personlig tolkning och skildrat detta i analysen. I min uppsats har jag visat att romanen har en hybridliknande struktur genom häxan Baba Jaga som saknar egenskaper och genom myten som saknar kärna. Jag har även visat detta genom den lekfulla berättarstrukturen och genreblandningen. Detta tydliggörs framförallt genom karaktärena i romanen som alla saknar identiteskärnor samt genom att författaren hävdar att alla kvinnor kan vara potentiella Baba Jagor.
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Introduktion: För att ett barn skall utvecklas optimalt behöver det en anknytningsperson. Föräldraskapet blir alltmer jämställt och pappor är i högre uträckning, jämfört med tidigare, hemma tillsammans med sina barn. Mycket av tidigare forskning har fokuserat på mamman och barnet. Syfte: Syftet med studien var att beskriva pappans uppfattningar av det egna lilla barnets anknytning till honom. Syftet var också att beskriva pappans uppfattningar av föräldrastöd. Metod: Detta var en kvalitativ intervjustudie inspirerad av fenomenografi. Deltagarna var pappor till barn som var mellan 3 och 14 månader. Resultat: Pappan såg barnets anknytning till honom som en relation, ett starkt villkorslöst band som innebar kärlek och trygghet. Han försökte underlätta barnets anknytning till honom. Det fanns delade meningar om stödet från barnhälsovården, pappan fick stöd från barnets mamma. Slutsats: För att stötta pappan på ett effektivt sätt i föräldraskapet kvävs en förståelse för pappors uppfattningar och erfarenheter av barnets anknytning, här har sjuksköterskan inom barnhälsovården en viktig uppgift att fylla. Författarna anser att det vore av betydelse att i vidare forskning studera hur personalen inom barnhälsovården arbetar för att främja barns anknytning till pappan.