Intracellular Vesicles as Reproduction Elements in Cell Wall-Deficient L-Form Bacteria

Cell wall-deficient bacteria, or L-forms, represent an extreme example of bacterial plasticity. Stable L-forms can multiply and propagate indefinitely in the absence of a cell wall. Data presented here are consistent with the model that intracellular vesicles in Listeria monocytogenes L-form cells represent the actual viable reproductive elements. First, small intracellular vesicles are formed along the mother cell cytoplasmic membrane, originating from local phospholipid accumulation. During growth, daughter vesicles incorporate a small volume of the cellular cytoplasm, and accumulate within volume-expanding mother cells. Confocal Raman microspectroscopy demonstrated the presence of nucleic acids and proteins in all intracellular vesicles, but only a fraction of which reveals metabolic activity. Following collapse of the mother cell and release of the daughter vesicles, they can establish their own membrane potential required for respiratory and metabolic processes. Premature depolarization of the surrounding membrane promotes activation of daughter cell metabolism prior to release. Based on genome resequencing of L-forms and comparison to the parental strain, we found no evidence for predisposing mutations that might be required for L-form transition. Further investigations revealed that propagation by intracellular budding not only occurs in Listeria species, but also in L-form cells generated from different Enterococcus species. From a more general viewpoint, this type of multiplication mechanism seems reminiscent of the physicochemical self-reproducing properties of abiotic lipid vesicles used to study the primordial reproduction pathways of putative prokaryotic precursor cells

Predicting Weight Outcomes in Preadolescence: The Role of Toddlers? Self-regulation Skills and the Temperament Dimension of Pleasure

Objective To investigate the role of toddlers? self-regulation skills and temperament in predicting weight outcomes in preadolescence. Method Participants for this study included 195 children (114 girls) obtained from three different cohorts participating in a larger ongoing longitudinal study. At 2 years of age, participants participated in several laboratory tasks designed to assess their self-regulation abilities, including emotion regulation, sustained attention, and delay of gratification, while parents filled out a temperament questionnaire to assess toddlers? pleasure expression. Height and weight measures were collected when children were 4, 5, 7, and 10 years of age. Children also filled out a body image and eating questionnaire at the 10 year visit. Results Self-regulation skills in toddlers were associated with both BMI development, pediatric obesity, and body image/eating concerns. The temperament dimension of pleasure was also associated with BMI development and pediatric obesity but not body image/eating concerns. Conclusion Self-regulation difficulties across domains as well as temperament based pleasure in toddlers represented significant individual risk factors for the development of pediatric obesity eight years later. Early self-regulation difficulties also contributed to body image and eating concerns that typically accompanied overweight children. The mechanisms by which early self-regulation skills and temperament based pleasure may contribute to the development of pediatric obesity and associated weight concerns are discussed

Development of Secondary Woodland in Oak Wood Pastures Reduces the Richness of Rare Epiphytic Lichens

Wooded pastures with ancient trees were formerly abundant throughout Europe, but during the last century, grazing has largely been abandoned often resulting in dense forests. Ancient trees constitute habitat for many declining and threatened species, but the effects of secondary woodland on the biodiversity associated with these trees are largely unknown. We tested for difference in species richness, occurrence, and abundance of a set of nationally and regionally red-listed epiphytic lichens between ancient oaks located in secondary woodland and ancient oaks located in open conditions. We refined the test of the effect of secondary woodland by also including other explanatory variables. Species occurrence and abundance were modelled jointly using overdispersed zero-inflated Poisson models. The richness of the red-listed lichens on ancient oaks in secondary woodland was half of that compared with oaks growing in open conditions. The species-level analyses revealed that this was mainly the result of lower occupancy of two of the study species. The tree-level abundance of one species was also lower in secondary woodland. Potential explanations for this pattern are that the study lichens are adapted to desiccating conditions enhancing their population persistence by low competition or that open, windy conditions enhance their colonisation rate. This means that the development of secondary woodland is a threat to red-listed epiphytic lichens. We therefore suggest that woody vegetation is cleared and grazing resumed in abandoned oak pastures. Importantly, this will also benefit the vitality of the oaks

Constitutive Activation of PrfA Tilts the Balance of Listeria monocytogenes Fitness Towards Life within the Host versus Environmental Survival

PrfA is a key regulator of Listeria monocytogenes pathogenesis and induces the expression of multiple virulence factors within the infected host. PrfA is post-translationally regulated such that the protein becomes activated upon bacterial entry into the cell cytosol. The signal that triggers PrfA activation remains unknown, however mutations have been identified (prfA* mutations) that lock the protein into a high activity state. In this report we examine the consequences of constitutive PrfA activation on L. monocytogenes fitness both in vitro and in vivo. Whereas prfA* mutants were hyper-virulent during animal infection, the mutants were compromised for fitness in broth culture and under conditions of stress. Broth culture prfA*-associated fitness defects were alleviated when glycerol was provided as the principal carbon source; under these conditions prfA* mutants exhibited a competitive advantage over wild type strains. Glycerol and other three carbon sugars have been reported to serve as primary carbon sources for L. monocytogenes during cytosolic growth, thus prfA* mutants are metabolically-primed for replication within eukaryotic cells. These results indicate the critical need for environment-appropriate regulation of PrfA activity to enable L. monocytogenes to optimize bacterial fitness inside and outside of host cells

Temporal abundance of Aedes aegypti in Manaus, Brazil, measured by two trap types for adult mosquitoes

A longitudinal study was conducted in Manaus, Brazil, to monitor changes of adult Aedes aegypti (L.) abundance. The objectives were to compare mosquito collections of two trap types, to characterise temporal changes of the mosquito population, to investigate the influence of meteorological variables on mosquito collections and to analyse the association between mosquito collections and dengue incidence. Mosquito monitoring was performed fortnightly using MosquiTRAPs (MQT) and BG-Sentinel (BGS) traps between December 2008-June 2010. The two traps revealed opposing temporal infestation patterns, with highest mosquito collections of MQTs during the dry season and highest collections of BGS during the rainy seasons. Several meteorological variables were significant predictors of mosquito collections in the BGS. The best predictor was the relative humidity, lagged two weeks (in a positive relationship). For MQT, only the number of rainy days in the previous week was significant (in a negative relationship). The correlation between monthly dengue incidence and mosquito abundance in BGS and MQT was moderately positive and negative, respectively. Catches of BGS traps reflected better the dynamic of dengue incidence. The findings help to understand the effects of meteorological variables on mosquito infestation indices of two different traps for adult dengue vectors in Manaus

”Vi kallade bajsblöjorna för pappablöjorna” : En kvalitativ uppsats om pappors upplevelser av omsorgen av sina barn

Det finns fördelar med att ha ett jämställt föräldraskap, exempelvis kan parrelationen stärkas, men även relationen mellan föräldrar och barn. Idag är det vanligare att pappor är hemma med sina barn, än det var när föräldraförsäkringen introducerades 1974, trots det, är det fortfarande mammorna som tar ut mest ledighet och står för större delen av hushållsarbetet. Syftet med denna undersökning var således att undersöka pappors upplevelser av omsorgen av sina barn. Insamlingen av empiri för undersökningen har skett genom semistrukturerade intervjuer med sju pappor. Det teoretiska ramverket har utgått ifrån teorier och begrepp från identitets- och genusteorier, vilka sedan har använts för att analysera den insamlade empirin. Undersökningens resultat visade att pappor vill dela lika på ledigheten och hushållsarbetet med sin partner, men i de fall där ledigheten inte hade delats lika var amning förklaringen papporna gav som anledning till att mamman varit hemma första tiden och längre, vilket indikerade på att det kan finnas incitament som gör att papporna inte är hemma i samma utsträckning som mammorna. Papporna upplevde även att deras parförhållanden var jämställda, trots att det fanns olika definitioner om vad som var en jämställd arbetsdelning. Exempelvis visade det sig att trots ett uttalat jämställdhetstänk, tog mammorna ansvar för det praktiska, medan papporna var källan till lek och bus, något som kunde anses befästa könsnormer. Resultatet visade även att papporna upplever att det finns olika förväntningar på dem när det kommer till föräldraskapet. Det kunde synliggöras genom att det fanns inre eller yttre faktorer som symboliserade hur pappor bör vara. Resultatet diskuterades sedan utifrån undersökningens forskningsfrågor, där det bland annat argumenterades för ifall amning ska ses som ett incitament till att mammorna tar ut fler föräldradagar, om papporna kan anses vara jämställda och pappornas relation till sina barn

NATO 1989-2015 : NATO:s säkerhetpolitiska arbetsprocessfrån 1989 till 2015 sett utifrån Berlinmurensfall och konflikten i Afghanistan

The main purpose with the essay is to look into NATO and annalise how the organisation haschanged it´s security policy work process today 2015, seen from two different world eventsduring the period 1989-2015, the collapse of the Berlin wall and war in Afghanistan. Purposeand issuses also apply based on two theories Anarchymodel and World society model. In orderto highlight two different ways to see NATO:s security policy work process over time untilthe present day. Issues: • How did the fall of Berlin wall in 1989 change NATO:s security policy work process? • How did the war in Afghanistan in 2001 change NATO:s security policy work process? The essay is a qualitative method literature review describing NATO as an organisation andworld events that had impact on NATO over time. The result show that NATO has shifled it´s borders further fast because ”new” membercountries from the former Soviet Union are party members. NATO has moved closer toRussia, and increased in momentum. A possible armed conflict could be in the advantage ofnew markets that werwe previously isolated and intiate a co-operation with entrant´s. The result also shows that terroism and conflicts are carried out between operators and groupswithout fixed borders. It is largely down to the balance of power between NATO and Warsawpact dosesn´t exist anymore. Earlier controlled Superpowers of their allies. It has providedspace for new opponents to understand rights and responsibilities according to their way ofthinking and acting on that basis. These operators are weaker in impact strength and hencethey act according to their own circumstances and conditions, often through terroism. NATOhas transformed a large part of it´s security policy process to better respond to threats such asterroism