No Evidence for Trade-Offs: Centaurea Plants from America are Better Competitors and Defenders

The natural enemies hypothesis has led to a number of ideas by which invaders might evolve superior competitive ability. In this context, we compared growth, reproduction, competitive effect, competitive response, and defense capabilities between invasive North American populations of Centaurea maculosa and populations in Europe, where the species is native. We found that Centaurea from North America were larger than plants from European populations. North American Centaurea also demonstrated stronger competitive effects and responses than European Centaurea. However, competitive superiority did not come at a cost to herbivore defense. North American plants were much better defended against generalist insect herbivores and slightly better defended against specialists. North Americans showed a stronger inhibitory effect on the consumers (resistance) and a better ability to regrow after attack by herbivores (tolerance). Better defense by North Americans corresponded with higher constitutive levels of a biochemical defense compound precursor, tougher leaves, and more leaf trichomes than Europeans. North American F1 progeny of field collected lines retained the traits of larger size and greater leaf toughness suggesting that genetic differences, rather than maternal effects, may be the cause of intercontinental differences, but these sample sizes were small. Our results suggest that the evolution of increased competitive ability may not always be driven by physiological trade-offs between the allocation of energy or resources to growth or to defense. Instead, we hypothesize that Centaurea maculosa experiences strong directional selection on novel competitive and defense traits in its new range

Plant origin and ploidy influence gene expression and life cycle characteristics in an invasive weed

Background: Ecological, evolutionary and physiological studies have thus far provided an incomplete picture of why some plants become invasive; therefore we used genomic resources to complement and advance this field. In order to gain insight into the invasive mechanism of Centaurea stoebe we compared plants of three geo-cytotypes, native Eurasian diploids, native Eurasian tetraploids and introduced North American tetraploids, grown in a common greenhouse environment. We monitored plant performance characteristics and life cycle habits and characterized the expression of genes related to constitutive defense and genome stability using quantitative PCR. Results: Plant origin and ploidy were found to have a significant effect on both life cycle characteristics and gene expression, highlighting the importance of comparing appropriate taxonomic groups in studies of native and introduced plant species. We found that introduced populations of C. stoebe exhibit reduced expression of transcripts related to constitutive defense relative to their native tetraploid counterparts, as might be expected based on ideas of enemy release and rapid evolution. Measurements of several vegetative traits were similar for all geo-cytotypes; however, fecundity of tetraploids was significantly greater than diploids, due in part to their polycarpic nature. A simulation of seed production over time predicts that introduced tetraploids have the highest fecundity of the three geo-cytotypes. Conclusion: Our results suggest that characterizing gene expression in an invasive species using populations from both its native and introduced range can provide insight into the biology of plant invasion that can complement traditional measurements of plant performance. In addition, these results highlight the importance of using appropriate taxonomic units in ecological genomics investigations

Plant neighbor identity influences plant biochemistry and physiology related to defense

<p>Abstract</p> <p>Background</p> <p>Chemical and biological processes dictate an individual organism's ability to recognize and respond to other organisms. A small but growing body of evidence suggests that plants may be capable of recognizing and responding to neighboring plants in a species specific fashion. Here we tested whether or not individuals of the invasive exotic weed, <it>Centaurea maculosa</it>, would modulate their defensive strategy in response to different plant neighbors.</p> <p>Results</p> <p>In the greenhouse, <it>C. maculosa </it>individuals were paired with either conspecific (<it>C. maculosa</it>) or heterospecific (<it>Festuca idahoensis</it>) plant neighbors and elicited with the plant defense signaling molecule methyl jasmonate to mimic insect herbivory. We found that elicited <it>C. maculosa </it>plants grown with conspecific neighbors exhibited increased levels of total phenolics, whereas those grown with heterospecific neighbors allocated more resources towards growth. To further investigate these results in the field, we conducted a metabolomics analysis to explore chemical differences between individuals of <it>C. maculosa </it>growing in naturally occurring conspecific and heterospecific field stands. Similar to the greenhouse results, <it>C. maculosa </it>individuals accumulated higher levels of defense-related secondary metabolites and lower levels of primary metabolites when growing in conspecific versus heterospecific field stands. Leaf herbivory was similar in both stand types; however, a separate field study positively correlated specialist herbivore load with higher densities of <it>C. maculosa </it>conspecifics.</p> <p>Conclusions</p> <p>Our results suggest that an individual <it>C. maculosa </it>plant can change its defensive strategy based on the identity of its plant neighbors. This is likely to have important consequences for individual and community success.</p

Sneddon syndrome a case report and literature review

Sneddon’s syndrome (SS) is characterized by livedo racemosa (LR) or reticularis and recurrent ischemic strokes. At the skin and brain level a non-inflammatory thrombotic vasculopathy is observed. Almost 80% of cases are women around 40 years old. The most accepted etiological proposal is an autoimmune and inflammatory mechanism versus the presence of thrombophilia. Neurological manifestations occur in 3 phases: prodromal symptoms (headache, dizziness, and vertigo), recurrent strokes, and early-onset dementia. Livedo racemosa has been reported to precede strokes by more than 10 years. Treatment is mainly based on secondary prophylaxis preventing a stroke with antiplatelet and antithrombotic agents. The neuropsychiatric prognosis is relatively poor with deficits in concentration, attention, visual perception, and visuospatial skills

Opcions disponibles en la cirurgia de la malaltia de Parkinson i la tremolor essencial

Parkinson; Tremolor; CirurgiaParkinson; Temblor; CirugíaParkinson's; Shaking; SurgeryAquest document conté una revisió de revisions i d’informes de síntesi, en què s’han seleccionat els informes d’avaluació de tecnologies sanitàries i les guies de pràctica clínica, s’han descrit de forma narrativa els resultats i, mitjançant la tècnica qualitativa de grup nominal, s’ha elaborat una taula comparativa amb recomanacions sobre les indicacions per a cada tipus de tècnica quirúrgica.Este documento contiene una revisión de revisiones y de informes de síntesis, en que se han seleccionado los informes de evaluación de tecnologías sanitarias y las guías de práctica clínica. Se han descrito de forma narrativa los resultados y, mediante la técnica cualitativa de grupo nominal, se ha elaborado una mesa comparativa con recomendaciones sobre las indicaciones para cada tipo de técnica quirúrgica.This document contains review of reviews and synthesis reports has been prepared, in which health technology assessment reports and clinical practice guidelines were selected. The results have been described narratively, and, through a qualitative nominal group technique, a comparative table has been drawn up with recommendations on indications for each type surgical intervention

Correction: Neuronal Hyperactivity Disturbs ATP Microgradients, Impairs Microglial Motility, and Reduces Phagocytic Receptor Expression Triggering Apoptosis/Microglial Phagocytosis Uncoupling

Correction de l'article DOI: 10.1371/journal.pbio.100246

Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF

M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe