PCAC Relation and Pion Production-Absorption in Nuclei

Nuclear PCAC relation is studied in the framework of the effective theory of nuclear interaction, in which the interaction of real pion production-absorption is expressed by many-body operators, and does not include the one-nucleon operator as was assumed in the conventional works, while the effective axial-vector current includes the one-nucleon current in contrast to the former interaction. This problem is investigated under the simple linear $\sigma$-model. Results are as folows: 1) The theory describes consistently the PCAC relation and the pion production-absorption process. 2) The conventional interpretation of the effective pion source function as the interaction Hamiltonian of pion production-absorption does not hold. 3) The effective pion source function still includes the one-nucleon operator for the pion production-absorption at threshold effectively, which may justify the conventional theory.Comment: 12 pages, 3 figure

Photoemission Properties of LaB6 and CeB6 Under Various Temperature and Incident Photon Energy Conditions

IPAC2016, Busan, KoreaPhotoemission properties of LaB₆ and CeB₆ were investigated at various cathode temperatures and different wavelengths of excitation laser to study for application of electron gun, especially for RF injector of infrared FEL facilities. It was found that the LaB₆ had higher photoemission property than CeB₆ at the same cathode temperature. In addition, LaB₆ can emit a measurable photoemission current being irradiated by laser with energy below work function at the cathode temperature higher than 1400 K. With increasing laser energy (over work function), a photoemission dependency on cathode temperature was getting lower. As the result, LaB₆ is revealed to have better properties than CeB₆ since LaB₆ has higher quantum efficiency than CeB₆ at same temperature

The Group B Streptococcal Adhesin BspC Interacts with Host Cytokeratin 19 To Promote Colonization of the Female Reproductive Tract

Streptococcus agalactiae, otherwise known as Group B Streptococcus (GBS), is an opportunistic pathogen that vaginally colonizes approximately one third of healthy women. During pregnancy, this can lead to in utero infection, resulting in premature rupture of membranes, chorioamnionitis, and stillbirths. Furthermore, GBS causes serious infection in newborns, including sepsis, pneumonia, and meningitis. Previous studies have indicated that GBS antigen (Ag) I/II family proteins promote interaction with vaginal epithelial cells; thus, we hypothesized that the Ag I/II Group B streptococcal surface protein C (BspC) contributes to GBS colonization of the female reproductive tract (FRT). Here, we show that a ΔbspC mutant has decreased bacterial adherence to vaginal, ecto-, and endocervical cells, as well as decreased auto-aggregation and biofilm-like formation on cell monolayers. Using a murine model of vaginal colonization, we observed that the ΔbspC mutant strain exhibited a significant fitness defect compared to wild-type (WT) GBS and was less able to ascend to the cervix and uterus in vivo, resulting in reduced neutrophil chemokine signaling. Furthermore, we determined that BspC interacts directly with the host intermediate filament protein cytokeratin 19 (K19). Surface localization of K19 was increased during GBS infection, and interaction was mediated by the BspC variable (V) domain. Finally, mice treated with a drug that targets the BspC V-domain exhibited reduced bacterial loads in the vaginal lumen and reproductive tissues. These results demonstrate the importance of BspC in promoting GBS colonization of the FRT and that it may be targeted therapeutically to reduce GBS vaginal persistence and ascending infection

A Low Percent Ethanol Method for Immobilizing Planarians

Planarians have recently become a popular model system for the study of adult stem cells, regeneration and polarity. The system is attractive for both undergraduate and graduate research labs, since planarian colonies are low cost and easy to maintain. Also in situ hybridization, immunofluorescence and RNA-interference (RNAi) gene knockdown techniques have been developed for planarian studies. However, imaging of live worms (particularly at high magnifications) is difficult because animals are strongly photophobic; they quickly move away from light sources and out of frame. The current methods available to inhibit movement in planarians include RNAi injection and exposure to cold temperatures. The former is labor and time intensive, while the latter precludes the use of many fluorescent reporter dyes. Here, we report a simple, inexpensive and reversible method to immobilize planarians for live imaging. Our data show that a short 1 hour treatment with 3% ethanol (EtOH) is sufficient to inhibit both the fine and gross movements of Schmidtea mediterranea planarians, of the typical size used (4–6 mm), with full recovery of movement within 3–4 hours. Importantly, EtOH treatment did not interfere with regeneration, even after repeated exposure, nor lyse epithelial cells (as assayed by H&E staining). We demonstrate that a short exposure to a low concentration of EtOH is a quick and effective method of immobilizing planarians, one that is easily adaptable to planarians of all sizes and will increase the accessibility of live imaging assays to planarian researchers

Shallow water marine sediment bacterial community shifts along a natural CO2 gradient in the Mediterranean Sea off Vulcano, Italy.

The effects of increasing atmospheric CO(2) on ocean ecosystems are a major environmental concern, as rapid shoaling of the carbonate saturation horizon is exposing vast areas of marine sediments to corrosive waters worldwide. Natural CO(2) gradients off Vulcano, Italy, have revealed profound ecosystem changes along rocky shore habitats as carbonate saturation levels decrease, but no investigations have yet been made of the sedimentary habitat. Here, we sampled the upper 2 cm of volcanic sand in three zones, ambient (median pCO(2) 419 μatm, minimum Ω(arag) 3.77), moderately CO(2)-enriched (median pCO(2) 592 μatm, minimum Ω(arag) 2.96), and highly CO(2)-enriched (median pCO(2) 1611 μatm, minimum Ω(arag) 0.35). We tested the hypothesis that increasing levels of seawater pCO(2) would cause significant shifts in sediment bacterial community composition, as shown recently in epilithic biofilms at the study site. In this study, 454 pyrosequencing of the V1 to V3 region of the 16S rRNA gene revealed a shift in community composition with increasing pCO(2). The relative abundances of most of the dominant genera were unaffected by the pCO(2) gradient, although there were significant differences for some 5 % of the genera present (viz. Georgenia, Lutibacter, Photobacterium, Acinetobacter, and Paenibacillus), and Shannon Diversity was greatest in sediments subject to long-term acidification (>100 years). Overall, this supports the view that globally increased ocean pCO(2) will be associated with changes in sediment bacterial community composition but that most of these organisms are resilient. However, further work is required to assess whether these results apply to other types of coastal sediments and whether the changes in relative abundance of bacterial taxa that we observed can significantly alter the biogeochemical functions of marine sediments

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus -- the "D-shuttle" project --

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter "D-shuttle" for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the background radiation level of other regions/countries

Combining C-H functionalisation and flow photochemical heterocyclic metamorphosis (FP-HM) for the synthesis of benzo[1,3]oxazepines

C-H Activation/functionalisation and Flow Photochemical Heterocyclic Metamorphosis (FP-HM) have been combined to synthesize a library of benzo[1,3]oxazepines, a rarely described heterocyclic family. This combined protocol allows a range of arylated products to be made from simple starting materials, and the cheap flow photochemical system has proven effective for rapid synthesis of gram-quantities of benzo[1,3]oxazepines

Identification of N-homocysteinylated apolipoprotein AI in normal human serum

Background: In human serum, a portion of homocysteine (Hcy) exists as an N-linked form to the {varepsilon}-amino group of protein lysine residues. N-homocysteinylated proteins differ structurally and functionally from native proteins. The present study strives to develop detection and potential semi-quantification methods for N-homocysteinylated apolipoprotein AI (N-Hcy-apoAI) in human serum.Methods: Serum treated with or without cysteamine was supplied to isoelectric focusing (IEF) followed by an immunoblot using an anti-apoAI antibody. Cysteamine treatment increased the isoelectric point for N-Hcy-apoAI, but not for unmodified apoAI, due to the presence of -SH group(s) derived from Hcy and the absence of a cysteine residue in the apoAI molecule. N-Hcy-apoAI was semi-quantified from the scanned immunoblot pattern via a computer.Results: After cysteamine treatment, N-Hcy-apoAI in the serum was identified by IEF at the position with a higher pI value compared with intact apoAI. The reproducibility (between assays) of the semi-quantification method was 19.1% CV (coefficient of variation) for an average ratio 5.9% of N-Hcy-apoAI to the whole apoAI in the serum. Approximately 1.0–7.4% of apoAI was N-homocysteinylated in the serum obtained from 27 healthy subjects. Neither the ratio of N-Hcy-apoAI nor its concentration, calculated by total apoAI concentration, indicated correlation with the so-called total (free and S-linked) Hcy concentration.Conclusions: We directly found that a portion of apoAI in the serum undergoes homocysteinylation in an N-linkage manner, and used this to develop a potential semi-quantification method for N-Hcy-apoAI

Functional discrimination of membrane proteins using machine learning techniques

<p>Abstract</p> <p>Background</p> <p>Discriminating membrane proteins based on their functions is an important task in genome annotation. In this work, we have analyzed the characteristic features of amino acid residues in membrane proteins that perform major functions, such as channels/pores, electrochemical potential-driven transporters and primary active transporters.</p> <p>Results</p> <p>We observed that the residues Asp, Asn and Tyr are dominant in channels/pores whereas the composition of hydrophobic residues, Phe, Gly, Ile, Leu and Val is high in electrochemical potential-driven transporters. The composition of all the amino acids in primary active transporters lies in between other two classes of proteins. We have utilized different machine learning algorithms, such as, Bayes rule, Logistic function, Neural network, Support vector machine, Decision tree etc. for discriminating these classes of proteins. We observed that most of the algorithms have discriminated them with similar accuracy. The neural network method discriminated the channels/pores, electrochemical potential-driven transporters and active transporters with the 5-fold cross validation accuracy of 64% in a data set of 1718 membrane proteins. The application of amino acid occurrence improved the overall accuracy to 68%. In addition, we have discriminated transporters from other α-helical and β-barrel membrane proteins with the accuracy of 85% using k-nearest neighbor method. The classification of transporters and all other proteins (globular and membrane) showed the accuracy of 82%.</p> <p>Conclusion</p> <p>The performance of discrimination with amino acid occurrence is better than that with amino acid composition. We suggest that this method could be effectively used to discriminate transporters from all other globular and membrane proteins, and classify them into channels/pores, electrochemical and active transporters.</p