Supposed alderfly larva (Insecta, Megaloptera) from the Jurassic locality Shar-Teg, southwestern Mongolia

The first Mesozoic alderfly larva of Sharasialis fusiformis gen. et sp. nov. is described from the Upper Jurassic Lagerst?tte of Shar-Teg (southwestern Mongolia). In contrast to Cenozoic alderflies, it has a short thick appendage instead of a long terminal filament.     

X-ray spectroscopy and imaging of selenium in living systems

Background

Selenium is an essential element with a rich and varied chemistry in living organisms. It plays a variety of important roles ranging from being essential in enzymes that are critical for redox homeostasis to acting as a deterrent for herbivory in hyperaccumulating plants. Despite its importance there are many open questions, especially related to its chemistry in situ within living organisms.

New Triassic beetles (Coleoptera) from northern European Russia

Beetle remains from the Triassic Khey-Yaga locality, Nenets National District, Korotaikha Basin, Nyadeita Formation, Olenekian-Anisian are described. Only isolated elytra have been found. Tetracoleus tshalyshevi gen. et sp. nov. and T. minimus sp. nov. are described and assigned to Tricoleidae, and six new species are described in formal taxa. Tetracoleus is close to Permian tricoleids just found in the Newcastle Group of Australia and the Vyatkian Aristovo locality of northern European Russia. The composition of elytra in the locality is closer to that of Lower Triassic localities than other Middle Triassic localities and characterizes the beginning of a recovery after the Permian-Triassic ecological crisis. Longxianocupes Hong in Liu, Liu et Hong, 1985 is shown to be a junior synonym of Sogdelytron Ponomarenko, 1969. The species Palademosyne ovum Ponomarenko, 2004, P. elongatum Ponomarenko, 2004, and P. latum Ponomarenko, 2004 are transferred to the genus Pseudochrysomelites Handlirsch, 1906.     

Structural and spectropotentiometric analysis of Blastochloris viridis heterodimer mutant reaction center

Heterodimer mutant reaction centers (RCs) of Blastochloris viridis were crystallized using microfluidic technology. In this mutant, a leucine residue replaced the histidine residue which had acted as a fifth ligand to the bacteriochlorophyll (BChl) of the primary electron donor dimer M site (HisM200). With the loss of the histidine-coordinated Mg, one bacteriochlorophyll of the special pair was converted into a bacteriopheophytin (BPhe), and the primary donor became a heterodimer supermolecule. The crystals had dimensions 400 × 100 × 100 μm, belonged to space group P4₃2₁2, and were isomorphous to the ones reported earlier for the wild type (WT) strain. The structure was solved to a 2.5 Å resolution limit. Electron-density maps confirmed the replacement of the histidine residue and the absence of Mg. Structural changes in the heterodimer mutant RC relative to the WT included the absence of the water molecule that is typically positioned between the M side of the primary donor and the accessory BChl, a slight shift in the position of amino acids surrounding the site of the mutation, and the rotation of the M194 phenylalanine. The cytochrome subunit was anchored similarly as in the WT and had no detectable changes in its overall position. The highly conserved tyrosine L162, located between the primary donor and the highest potential heme C₃₈₀, revealed only a minor deviation of its hydroxyl group. Concomitantly to modification of the BChl molecule, the redox potential of the heterodimer primary donor increased relative to that of the WT organism (772 mV vs. 517 mV). The availability of this heterodimer mutant and its crystal structure provides opportunities for investigating changes in light-induced electron transfer that reflect differences in redox cascades.     

Limitations of Ab Initio Predictions of Peptide Binding to MHC Class II Molecules

Successful predictions of peptide MHC binding typically require a large set of binding data for the specific MHC molecule that is examined. Structure based prediction methods promise to circumvent this requirement by evaluating the physical contacts a peptide can make with an MHC molecule based on the highly conserved 3D structure of peptide:MHC complexes. While several such methods have been described before, most are not publicly available and have not been independently tested for their performance. We here implemented and evaluated three prediction methods for MHC class II molecules: statistical potentials derived from the analysis of known protein structures; energetic evaluation of different peptide snapshots in a molecular dynamics simulation; and direct analysis of contacts made in known 3D structures of peptide:MHC complexes. These methods are ab initio in that they require structural data of the MHC molecule examined, but no specific peptide:MHC binding data. Moreover, these methods retain the ability to make predictions in a sufficiently short time scale to be useful in a real world application, such as screening a whole proteome for candidate binding peptides. A rigorous evaluation of each methods prediction performance showed that these are significantly better than random, but still substantially lower than the best performing sequence based class II prediction methods available. While the approaches presented here were developed independently, we have chosen to present our results together in order to support the notion that generating structure based predictions of peptide:MHC binding without using binding data is unlikely to give satisfactory results.     

Hatching asynchrony and brood reduction influence immune response in Common Kestrel Falco tinnunculus nestlings

The onset of incubation before the end of laying imposes asynchrony at hatching and, therefore, a size hierarchy in the brood. It has been argued that hatching asynchrony might be a strategy to improve reproductive output in terms of quality or quantity of offspring. However, little is known about the mediating effect of hatching asynchrony on offspring quality when brood reduction occurs. Here, we investigate the relationship between phenotypic quality and hatching asynchrony in Common Kestrel Falco tinnunculus nestlings in Spain. Hatching asynchrony did not increase breeding success or nestling quality. Furthermore, hatching asynchrony and brood reduction had different effects on nestlings’ phytohaematogglutinin (PHA)‐mediated immune response and nestling growth. In asynchronous and reduced broods (in which at least one nestling died), nestlings showed a stronger PHA‐mediated immune response and tended to have a smaller body size compared with nestlings raised in synchronous and reduced broods. When brood reduction occurred in broods hatched synchronously, there was no effect on nestling size, but nestlings had a relatively poor PHA‐mediated immune response compared with nestlings raised in asynchronous and reduced broods. We suggest that resources for growth can be directed to immune function only in asynchronously hatched broods, resulting in improved nestling quality, as suggested by their immune response. We also found that males produced a greater PHA‐mediated immune response than females only in brood‐reduced nests without any effect on nestling size or condition, suggesting that females may trade off immune activities and body condition, size or weight. Overall, our results suggest that hatching pattern and brood reduction may mediate resource allocation to different fitness traits. They also highlight that the resolution of immune‐related trade‐offs when brood reduction occurs may differ between male and female nestlings.     

Knowledge-based technologies in proteomics

Proteomic technologies enable to identify thousands of proteins in biological samples. These data require appropriate means for storage, dissemination and analytical processing to decipher the new knowledge. Automatic processing of high-efficient experiment results is powered by the controlled vocabularies, such as Medical Subjects Headings and GeneOntology. While ontology and vocabularies undergo constant evolution, it is necessary to provide the centralized storage of proteomic data for further revision in accordance with the updated knowledge domain. Proteomic repositories like PRIDE, The Global Proteome Machine, PeptideAtlas etc. are available to harbor the wealth of mass spectral data and appropriate protein identifications. The existing repositories facilitate the development of knowledge extraction technologies to compare the list of identified proteins with the GeneOntology annotations, Medical Subjects Headings, metabolic and regulatory pathways. This paper reviews modern analytical tools that exploit the knowledge-based technologies for proteome research.     

Risk Factors for Death in 632 Patients with Sickle Cell Disease in the United States and United Kingdom

Background

The role of pulmonary hypertension as a cause of mortality in sickle cell disease (SCD) is controversial.

Methods and Results

We evaluated the relationship between an elevated estimated pulmonary artery systolic pressure and mortality in patients with SCD. We followed patients from the walk-PHaSST screening cohort for a median of 29 months. A tricuspid regurgitation velocity (TRV)≥3.0 m/s cuttof, which has a 67–75% positive predictive value for mean pulmonary artery pressure ≥25 mm Hg was used. Among 572 subjects, 11.2% had TRV≥3.0 m/sec. Among 582 with a measured NT-proBNP, 24.1% had values ≥160 pg/mL. Of 22 deaths during follow-up, 50% had a TRV≥3.0 m/sec. At 24 months the cumulative survival was 83% with TRV≥3.0 m/sec and 98% with TRV<3.0 m/sec (p<0.0001). The hazard ratios for death were 11.1 (95% CI 4.1–30.1; p<0.0001) for TRV≥3.0 m/sec, 4.6 (1.8–11.3; p = 0.001) for NT-proBNP≥160 pg/mL, and 14.9 (5.5–39.9; p<0.0001) for both TRV≥3.0 m/sec and NT-proBNP≥160 pg/mL. Age >47 years, male gender, chronic transfusions, WHO class III–IV, increased hemolytic markers, ferritin and creatinine were also associated with increased risk of death.

Conclusions

A TRV≥3.0 m/sec occurs in approximately 10% of individuals and has the highest risk for death of any measured variable.

The study is registered in ClinicalTrials.gov with identifier

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