Three embryonic cell lineages related with the epicardium show distinct developmental fates

The embryonic epicardium generates a population of mesenchymal cells that contribute to the coronary vessels and the connective tissue of the adult heart. We have used murine cell-tracing models to compare the developmental fate of three different lineages related with the epicardium. Mice bearing R26R-EYFP reporters were crossed with mice expressing Cre-recombinase under control of the promoters of the cardiac troponin gene (cTnT), the Wilms tumor suppressor gene (Wt1), and the G2 enhancer of the GATA4 gene. Thus, we could trace, using confocal microscopy and flow cytometry, the lineage of the cardiac cells expressing Wt1, cTnT and GATA4 under control of the G2 enhancer, from midgestation to adults. Additionally we have studied a knockin Wt1-GFP reporter model to detect cells with Wt1 expression in the developing and adult heart. During development, Wt1 is expressed in a major part of the proepicardium and epicardium, and also in some epicardial-derived mesenchymal cells, in part of the mesenchymal and coronary endothelial cells and also in a fraction of the cardiomyocytes. GATA4 expression is activated by the enhancer G2 in lateral mesoderm and pro/epicardium, but not in epicardial-derived cells, although most of these cells as well as some cardiomyocytes originate from a G2-GATA4 expressing lineage. cTnT is expressed in all the cardiomyocytes, but a part of the epicardial cells also derives from a cTnTCre-EYFP positive cell lineage. The developmental fate of these linages reveals interesting differences, according to our preliminary results. For example, the G2-GATA4 cell linage contributes more than the Wt1 cell lineage to the coronary endothelium during development. However, both lineages are highly represented in the adult cardiac endothelium, suggesting postnatal expression of Wt1 in the coronary endothelium and incorporation of endothelial progenitor cells from bone marrow (where the G2-GATA4 reporter is active in 20% of hematopoietic stem cells).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

From Tevatron's top and lepton-based asymmetries to the LHC

We define a lepton-based asymmetry in semi-leptonic ttbar production at the LHC. We show that the ratio of this lepton-based asymmetry and the ttbar charge asymmetry, measured as a function of the lepton transverse momentum or the ttbar invariant mass is a robust observable in the Standard Model. It is stable against higher order corrections and mis-modeling effects. We show that this ratio can also be a powerful discriminant among different new physics models and between them and the Standard Model. Finally, we show that a related ratio defined at the Tevatron is also robust as a function of the ttbar invariant mass.Comment: 20 page

Mandible fracture in children: a case report

The type of maxillofacial fractures in children and young adults varies with evolving skeletal anatomy and social and environmental factors. The  general principles of treating mandibular fractures are the same for children and adults: Anatomic reduction along with rigid skeletal stabilization is mandatory until bone union has occurred. Here we present a female child with a fall trauma accident, presenting with fractures of the symphysis, horizontally and vertically unfavourable, with significant displacement. Open reduction and internal fixation with miniplates and screws was done, with good postoperative recovery and outcome. Keywords: maxillofacial fracture, paediatric trauma, skeletal stabilizatio

Dominant negative phenotype of Bacillus thuringiensis Cry1Ab, Cry11Aa and Cry4Ba mutants suggest hetero-oligomer formation among different Cry toxins.

Background - Bacillus thuringiensis Cry toxins are used worldwide in the control of different insect pests important in agriculture or in human health. The Cry proteins are pore-forming toxins that affect the midgut cell of target insects. It was shown that non-toxic Cry1Ab helix a-4 mutants had a dominant negative (DN) phenotype inhibiting the toxicity of wildtype Cry1Ab when used in equimolar or sub-stoichiometric ratios (1:1, 0.5:1, mutant:wt) indicating that oligomer formation is a key step in toxicity of Cry toxins. Methodology/Principal Findings - The DN Cry1Ab-D136N/T143D mutant that is able to block toxicity of Cry1Ab toxin, was used to analyze its capacity to block the activity against Manduca sexta larvae of other Cry1 toxins, such as Cry1Aa, Cry1Ac, Cry1Ca, Cry1Da, Cry1Ea and Cry1Fa. Cry1Ab-DN mutant inhibited toxicity of Cry1Aa, Cry1Ac and Cry1Fa. In addition, we isolated mutants in helix a-4 of Cry4Ba and Cry11Aa, and demonstrate that Cry4Ba-E159K and Cry11Aa-V142D are inactive and completely block the toxicity against Aedes aegypti of both wildtype toxins, when used at sub-stoichiometric ratios, confirming a DN phenotype. As controls we analyzed Cry1Ab-R99A or Cry11Aa-E97A mutants that are located in helix a-3 and are affected in toxin oligomerization. These mutants do not show a DN phenotype but were able to block toxicity when used in 10:1 or 100:1 ratios (mutant:wt) probably by competition of binding with toxin receptors. Conclusions/Significance - We show that DN phenotype can be observed among different Cry toxins suggesting that may interact in vivo forming hetero-oligomers. The DN phenotype cannot be observed in mutants affected in oligomerization, suggesting that this step is important to inhibit toxicity of other toxin

COMPORTAMIENTO ALIMENTARIO DE JUVENILES Y ADULTOS DE LA GARZA ROJIZA (EGRETTA RUFESCENS) EN GUERRERO NEGRO, BAJA CALIFORNIA SUR, MÉXICO

Resumen ∙ La Garza Rojiza (Egretta rufescens) es la especie de la familia Ardeidae menos estudiada en Norteamérica, situación aún más evidente para las poblaciones mexicanas. En Guerrero Negro, Baja California Sur, México, el humedal artificial Salitrales 1A es una zona de alimentación aparentemente importante para esta especie. Durante el invierno (diciembre 2013–febrero 2014) estudiamos su comportamiento y eficiencia alimentarios por clase de edad (adultos ≥ 1 año y juveniles < 1 año). Observamos una disminución en la abundancia y proporción de adultos a partir de diciembre, asociada con un descenso en el nivel de agua. Los juveniles realizaron más intentos de captura de presas por minuto que los adultos (1,28 y 1,03, respectivamente), las tasas de captura de presas por minuto fueron similares (0,53 y 0,48), lo que resultó en una mayor eficiencia de los adultos (39% y 47% intentos de captura exitosos). La menor eficiencia de los juveniles se debe probablemente a una incipiente coordinación visual-motora y a la falta de experiencia para identificar las presas.Abstract ∙ Feeding behavior of juvenile and adult Reddish Egrets (Egretta rufescens) in Guerrero Negro, Baja California Sur, Mexico The Reddish Egret (Egretta rufescens) is the least well‐studied species of heron in North America, and even less is known for Mexican populations. In Guerrero Negro, Baja California Sur, the artificial wetland Salitrales 1A is an important feeding area for this species. During winter (December 2013–February 2014), we studied the feeding behavior and efficiency by age class (adults ≥ 1 year and juveniles < 1 year). We observed a decrease in the abundance and in the proportion of adults from December to February, associated with a reduction in the water level. Feeding attempts per minute by juveniles were higher than adults (1.28 and 1.03, respectively), the number of successful prey captures per minute was similar between both age classes (0.53 and 0.48), which resulted in greater feeding efficiency of adults (39% and 47% successful capture attempts). The lower efficiency of the juveniles is likely due to incipient visual‐motor coordination and the lack of experience to identify the prey

Dust Traps in the Protoplanetary Disk MWC 758: Two Vortices Produced by Two Giant Planets?

Resolved ALMA and VLA observations indicate the existence of two dust traps in the protoplanetary disc MWC 758. By means of two-dimensional gas+dust hydrodynamical simulations post-processed with three-dimensional dust radiative transfer calculations, we show that the spirals in scattered light, the eccentric, asymmetric ring and the crescent-shaped structure in the (sub)millimetre can all be caused by two giant planets: a 1.5-Jupiter mass planet at 35 au (inside the spirals) and a 5-Jupiter mass planet at 140 au (outside the spirals). The outer planet forms a dust-trapping vortex at the inner edge of its gap (at ∼85 au), and the continuum emission of this dust trap reproduces the ALMA and VLA observations well. The outer planet triggers several spiral arms that are similar to those observed in polarized scattered light. The inner planet also forms a vortex at the outer edge of its gap (at ∼50 au), but it decays faster than the vortex induced by the outer planet, as a result of the disc’s turbulent viscosity. The vortex decay can explain the eccentric inner ring seen with ALMA as well as the low signal and larger azimuthal spread of this dust trap in VLA observations. Finding the thermal and kinematic signatures of both giant planets could verify the proposed scenario

BRCA1 and BRCA2 founder mutations account for 78% of germline carriers among hereditary breast cancer families in Chile.

Identifying founder mutations in BRCA1 and BRCA2 in specific populations constitute a valuable opportunity for genetic screening. Several studies from different populations have reported recurrent and/or founder mutations representing a relevant proportion of BRCA mutation carriers. In Latin America, only few founder mutations have been described. We screened 453 Chilean patients with hereditary breast cancer for mutations in BRCA1 and BRCA2. For recurrent mutations, we genotyped 11 microsatellite markers in BRCA1 and BRCA2 in order to determine a founder effect through haplotype analysis. We found a total of 25 mutations (6 novel) in 71 index patients among which, nine are present exclusively in Chilean patients. Our analysis revealed the presence of nine founder mutations, 4 in BRCA1 and 5 in BRCA2, shared by 2 to 10 unrelated families and spread in different regions of Chile. Our panel contains the highest amount of founder mutations until today and represents the highest percentage (78%) of BRCA1 and BRCA2 mutation carriers. We suggest that the dramatic reduction of Amerindian population due to smallpox and wars with Spanish conquerors, a scarce population increase during 300 years, and the geographic position of Chile constituted a favorable scenario to establish founder genetic markers in our population

Radionuclides in arctic marine macroalgae from Kongsfjorden (Svalbard)

Seaweeds are known to be useful environmental bioindicators since they bioaccumulate radioisotopes at very low environmental concentrations. Levels of natural radionuclides in six ecologically relevant brown and red seaweed species from Arctic coasts (Kongsfjorden, Spitsbergen, Svalbard Islands) were analysed in the present study, in order to characterise the levels of natural radioactivity in this ecosystem and to compare this with previously published data in coastal areas from other latitudes. Thalli were collected by SCUBA divers at different depths in Hansneset in September 2014 and transported immediately to the laboratory. Young thalli, free from macroscopic epibiota, were dried, powdered and confined in a standard geometry before gamma spectrometry measurements. Then, the radioactivity of 7Be, 40K, 208Tl, 210Pb, 212Pb, 226Ra and 228Ra was measured by high-resolution gamma spectrometry using high-purity germanium detectors for 172800 s. Detectors were calibrated using a traceable multi gamma standard source and results are on a dry weight and fresh weight basis and are decay corrected to the date of sampling. Our results revealed the influence of cosmogenic radionuclides in the intertidal zone, as shown by the unique presence of 7Be in the brown macroalga Fucus distichus, the only analysed species inhabiting the intertidal. High concentrations of 40K were observed in all species, as this is one of the essential elements in biota. Remarkably is the high content of 210Pb in the red seaweeds Phycodrys rubens and Ptilota gunneri, suggesting that these species might possess a higher capacity for heavy metals bioaccumulation than the analysed brown seaweeds

Switching from natalizumab to fingolimod: an observational study

Background – Multiple sclerosis patients who discontinue using natalizumab are at risk of a rebound in disease activity. However, the optimal alternative therapy is not currently known. Aims of the study – We report on clinical and MRI data and patient safety in a group of relapsing–remitting multiple sclerosis patients who tested seropositive for the JC virus and who have switched from natalizumab to fingolimod because of concerns regarding PML risks. Methods – The test for JC virus antibodies was performed in 18 relapsing–remitting multiple sclerosis patients who were being treated with natalizumab for more than 1 year. Eight seropositive patients switched to fingolimod while the seronegative patients continued with natalizumab. Results – After switching to fingolimod, five of eight patients (63%) experienced clinical relapses, and MRI activity was detected in six of eight patients (75%). Neither clinical relapses nor MRI activity was observed in the patients who continued with natalizumab. No serious adverse effects were detected. Conclusions – Natalizumab is an effective treatment for relapsing–remitting multiple sclerosis, but its discontinuation continues to be a complex problem. All of the therapies tried thus far, including fingolimod, have been unable to control the reactivation of the disease. Further studies addressing alternative therapies after natalizumab discontinuation are necessary