Speciation in tropical seas: allopatry followed by range change

We investigated whether present distribution ranges in marine organisms are reliable indicators of the geographic pattern of past speciation events by assessing the level of geographic overlap (sympatric index) as a function of node age in four phylogenies of tropical marine species groups. The analyses led to remarkably similar results among the four groups examined with (1) most nodes associated with a sympatry index of either 0 (allopatry) or 1 (entire overlap) and (2) statistical support that sister species have an allopatric distribution significantly more frequently than sister clades (i.e. groups of species). Species divergences were expressed on a time scale and very similar times were needed for species range overlap to occur since sharp transitions from allopatry to sympatry occurred around 4 Ma in all groups. Present results supports that species range changes were not random as previous simulations results supports that species range probably evolve through occasional shifts of large amplitude. In front of the time needed for species range overlapping, our study suggests that species interaction and competitive exclusion can no longer be excluded as a driver of marine species distribution.     

Structure-function study of gemini derivatives with two different side chains at C-20, Gemini-0072 and Gemini-0097

Derivatives of vitamin D(3) containing a second side-chain emanating at C-20 are known as gemini and act as vitamin D receptor agonists. Recently, two of these, namely Gemini-0072 and the epimeric Gemini-0097, were selected for further studies in view of their high biological activities and lack of hypercalcemic effects. We now show that the two analogs recruit coactivator SRC-1 better than the parental gemini and act as VDR superagonists. The crystal structures of complexes of zVDR with Gemini-0072 and Gemini-0097 indicate that these ligands induce an extra cavity within the ligand-binding pocket similar to gemini and that their superagonistic activity is due to an increased stabilization of helix H12.     

Outcome prediction in pneumonia induced ALI/ARDS by clinical features and peptide patterns of BALF determined by mass spectrometry

Background

Peptide patterns of bronchoalveolar lavage fluid (BALF) were assumed to reflect the complex pathology of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) better than clinical and inflammatory parameters and may be superior for outcome prediction.

Methodology/Principal Findings

A training group of patients suffering from ALI/ARDS was compiled from equal numbers of survivors and nonsurvivors. Clinical history, ventilation parameters, Murray''s lung injury severity score (Murray''s LISS) and interleukins in BALF were gathered. In addition, samples of bronchoalveolar lavage fluid were analyzed by means of hydrophobic chromatography and MALDI-ToF mass spectrometry (MALDI-ToF MS).Receiver operating characteristic (ROC) analysis for each clinical and cytokine parameter revealed interleukin-6>interleukin-8>diabetes mellitus>Murray''s LISS as the best outcome predictors. Outcome predicted on the basis of BALF levels of interleukin-6 resulted in 79.4% accuracy, 82.7% sensitivity and 76.1% specificity (area under the ROC curve, AUC, 0.853). Both clinical parameters and cytokines as well as peptide patterns determined by MALDI-ToF MS were analyzed by classification and regression tree (CART) analysis and support vector machine (SVM) algorithms. CART analysis including Murray''s LISS, interleukin-6 and interleukin-8 in combination was correct in 78.0%. MALDI-ToF MS of BALF peptides did not reveal a single identifiable biomarker for ARDS. However, classification of patients was successfully achieved based on the entire peptide pattern analyzed using SVM. This method resulted in 90% accuracy, 93.3% sensitivity and 86.7% specificity following a 10-fold cross validation (AUC = 0.953). Subsequent validation of the optimized SVM algorithm with a test group of patients with unknown prognosis yielded 87.5% accuracy, 83.3% sensitivity and 90.0% specificity.

Conclusions/Significance

MALDI-ToF MS peptide patterns of BALF, evaluated by appropriate mathematical methods can be of value in predicting outcome in pneumonia induced ALI/ARDS.     

Invasion des Fichtenkreuzschnabels 1953

Ohne Zusammenfassung