SUMMARY
Close to 50% of the annual production of the brown alga Saccharina japonica, about 2 million tons (fresh weight), is produced through farming in Shandong province, China, principally around ...Rongcheng. Under artificial selection for phenotypic traits (e.g. color, blade length) cultivated strains (cultivars) face the problems of inbreeding depression, which can be caused by the close relationships of the parental plants. Hence, in an attempt to evaluate genetic variations and relationships among cultivars, 15 major farmed cultivars were selected and sampled from seven major hatcheries and analyzed using 15 microsatellite markers. A total of 94 alleles were found across all samples, with allele numbers ranging from three to 17 per locus. All of the cultivars exhibited relatively high levels of genetic diversity, with mean Nei's genetic diversity (H) and the Shannon's information index (I) of 0.466 and 0.862, respectively. A UPGMA dendrogram grouped all cultivars into three main clusters. However, two of the most commonly farmed cultivars (DB and BN) from different hatcheries failed to cluster together. Instead, differently named cultivars from the same hatchery tended to group together, implying that their high similarities is partly due to the presence of genetic mixing among cultivars within a hatchery or misuse of cultivar's names. Genetic analysis performed by Bayesian model‐based clustering revealed clear differentiation of three major subgroups (LJ‐202 and LJ‐205; LJ‐C033; XS‐2 and XS‐BN) and one admixed group (the remaining ten cultivars). Our results revealed ambiguous genetic relationships among certain cultivars of S. japonica farmed in northern China. A more stringent and prudent regulation should be applied during breeding and production process in the future.
The anionic sugar−phosphate backbone of nucleic acids substantially contributes to their structural flexibility. To model nucleic acid structure and dynamics correctly, the potentially sampled ...substates of the sugar−phosphate backbone must be properly described. However, because of the complexity of the electronic distribution in the nucleic acid backbone, its representation by classical force fields is very challenging. In this work, the three-dimensional potential energy surfaces with two independent variables corresponding to rotations around the α and γ backbone torsions are studied by means of high-level ab initio methods (B3LYP/6-31+G*, MP2/6-31+G*, and MP2 complete basis set limit levels). The ability of the AMBER ff99 Wang, J. M.; Cieplak, P.; Kollman, P. A. J. Comput. Chem. 2000, 21, 1049−1074 and parmbsc0 Perez, A.; Marchan, I.; Svozil, D.; Šponer, J.; Cheatham, T. E.; Laughten, C. A.; Orozco, M. Biophys. J. 2007, 92, 3817−3829 force fields to describe the various α/γ conformations of the DNA backbone accurately is assessed by comparing the results with those of ab initio quantum chemical calculations. Two model systems differing in structural complexity were used to describe the α/γ energetics. The simpler one, SPM, consisting of a sugar and methyl group linked through a phosphodiester bond was used to determine higher-order correlation effects covered by the CCSD(T) method. The second, more complex model system, SPSOM, includes two deoxyribose residues (without the bases) connected via a phosphodiester bond. It has been shown by means of a natural bond orbital analysis that the SPSOM model provides a more realistic representation of the hyperconjugation network along the C5′−O5′−P−O3′−C3′ linkage. However, we have also shown that quantum mechanical investigations of this model system are nontrivial because of the complexity of the SPSOM conformational space. A comparison of the ab initio data with the ff99 potential energy surface clearly reveals an incorrect ff99 force-field description in the regions where the γ torsion is in the trans conformation. An explanation is proposed for why the α/γ flips are eliminated so successfully when the parmbsc0 force-field modification is used.
Many scenarios of physics beyond the standard model predict the existence of new gauge singlets, which might be substantially lighter than the weak scale. The experimental constraints on additional ...scalars with masses in the MeV to GeV range could be significantly weakened if they interact predominantly with leptons rather than quarks. At an e+e− collider, such a leptophilic scalar (ϕL) would be produced predominantly through radiation from a τ lepton. We report herein a search for e+e−→τ+τ−ϕL, ϕL→ℓ+ℓ− (ℓ=e, μ) using data collected by the BABAR experiment at SLAC. No significant signal is observed, and we set limits on the ϕL coupling to leptons in the range 0.04<mϕL<7.0 GeV. These bounds significantly improve upon the current constraints, excluding almost entirely the parameter space favored by the observed discrepancy in the muon anomalous magnetic moment below 4 GeV at 90% confidence level.
Axionlike particles (ALPs) are predicted in many extensions of the standard model, and their masses can naturally be well below the electroweak scale. In the presence of couplings to electroweak ...bosons, these particles could be emitted in flavor-changing B meson decays. We report herein a search for an ALP, a, in the reaction B^{±}→K^{±}a, a→γγ using data collected by the BABAR experiment at SLAC. No significant signal is observed, and 90% confidence level upper limits on the ALP coupling to electroweak bosons are derived as a function of ALP mass, improving current constraints by several orders of magnitude in the range 0.175 GeV<m_{a}<4.78 GeV.
We report on a precision measurement of the ratio R_{τμ}^{ϒ(3S)}=B(ϒ(3S)→τ^{+}τ^{-})/B(ϒ(3S)→μ^{+}μ^{-}) using data collected with the BABAR detector at the SLAC PEP-II e^{+}e^{-} collider. The ...measurement is based on a 28 fb^{-1} data sample collected at a center-of-mass energy of 10.355 GeV corresponding to a sample of 122 million ϒ(3S) mesons. The ratio is measured to be R_{τμ}^{ϒ(3S)}=0.966±0.008_{stat}±0.014_{syst} and is in agreement with the standard model prediction of 0.9948 within 2 standard deviations. The uncertainty in R_{τμ}^{ϒ(3S)} is almost an order of magnitude smaller than the only previous measurement.
In this work the Pip-inducible system, already used in eukaryotes, was tested in mycobacteria. This system is based on the Streptomyces coelicolor Pip repressor, the Streptomyces pristinaespiralis ...ptr promoter and the inducer pristinamycin I. By cloning in an integrative plasmid the ptr promoter upstream of the lacZ reporter gene and the pip gene under the control of a constitutive mycobacterial promoter, we demonstrated that the ptr promoter activity increased up to 50-fold in Mycobacterium smegmatis and up to 400-fold in Mycobacterium tuberculosis, in dependence on pristinamycin I concentration, and that the promoter was fully repressed in the absence of the inducer.
Three mycobacterial genes were cloned under pptr–Pip control, both in sense and antisense direction; both proteins and antisense RNAs could be over-expressed, the antisenses causing a partial reduction of the amount of the targeted proteins. This system was used to obtain two M. tuberculosis conditional mutants in the fadD32 and pknB genes: the mutant strains grew only in the presence of the inducer pristinamycin I. Thus it showed to be an effective inducible system in mycobacteria.
We report on the first search for electron-muon lepton flavor violation (LFV) in the decay of a b quark and b antiquark bound state. We look for the LFV decay ϒ(3S)→e^{±}μ^{∓} in a sample of ...118 million ϒ(3S) mesons from 27 fb^{-1} of data collected with the BABAR detector at the SLAC PEP-II e^{+}e^{-} collider operating with a 10.36 GeV center-of-mass energy. No evidence for a signal is found, and we set a limit on the branching fraction Bϒ(3S)→e^{±}μ^{∓}<3.6×10^{-7} at 90% C. L. This result can be interpreted as a limit Λ_{NP}/g_{NP}^{2}>80 TeV on the energy scale Λ_{NP} divided by the coupling-squared g_{NP}^{2} of relevant new physics (NP).
Flavor physics of leptons and dipole moments Raidal, M.; van der Schaaf, A.; Bigi, I. ...
European physical journal. C, Particles and fields,
09/2008, Letnik:
57, Številka:
1-2
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
This chapter of the report of the “Flavor in the era of the LHC” Workshop discusses the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector ...and in flavor conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavor structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the standard model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
Recent investigations have suggested that the six-quark combination uuddss could be a deeply bound state (S) that has eluded detection so far, and a potential dark matter candidate. We report the ...first search for a stable, doubly strange six-quark state in ϒ→SΛover ¯Λover ¯ decays based on a sample of 90×10^{6}ϒ(2S) and 110×10^{6}ϒ(3S) decays collected by the BABAR experiment. No signal is observed, and 90% confidence level limits on the combined ϒ(2S,3S)→SΛover ¯Λover ¯ branching fraction in the range (1.2-1.4)×10^{-7} are derived for m_{S}<2.05 GeV. These bounds set stringent limits on the existence of such exotic particles.
IntroductionThe 2015 NCEPOD report1 found high rebleeding and mortality rates in patients with significant UGIB and recommended clearly documented rebleed plans. We audited the adequacy of rebleed ...plans at Nottingham University Hospitals, where 800 suspected UGIB patients are admitted annually.MethodPatients who underwent emergency endoscopy for suspected acute UGIB between June - August 2015 were identified. We analysed patient demographics, endoscopy (OGD) findings, re-bleed plans and clinical outcomes. Focused recommendations and education were delivered to all endoscopy unit staff. Re-audit was performed during June - July 2016 and outcomes compared.Results130 patients: 81 (62.6%) men, median (range) age 61 (14-92); 49 (37.4%) women, median (range) age 73 (34-96) years underwent urgent OGD following suspected acute UGIB between June -August 2015. 42 (32.3%) had endoscopic evidence of active UGIB (21 (16%) variceal haemorrhage (VH), and 21 (16%) non-variceal haemorrhage (NVH)) and 88 (67.7%) had no evidence of bleeding. Only 23.1% (n=30) who underwent urgent OGD had a re-bleed plan but was higher in those with (20/42 (47.6%); 11.9% re-bled, 5% mortality) rather than without (10/88 (11.4%); 5.7% re-bled; 0% mortality) endoscopic signs of bleeding.During the 4 week re-audit period after staff engagement and education, 42 patients (66.7% men, median age 60.5; 33.3% female, median age 77 years) underwent OGD for suspected UGIB. 21.4% had endoscopic evidence of active UGIB (7.1% VH; 14.3% NVH) and 78.6% had no evidence of bleeding. Rebleed plans improved overall from 23.1% to 46.3% and were higher in those with ((77.8%); 11.1% re-bled; 0% mortality) rather than without ((37.5%); 3.1% re-bled; 0% mortality) endoscopic signs of bleeding.Most frequent re-bleed plans were repeat OGD (34.7%), CT angiogram/interventional radiology (34.7%), conservative management (16.3%) or lower GI endoscopy (6.1%). Surgery was not recommended in any initial rebleed plan.ConclusionMost patients with suspected acute UGIB did not have endoscopic evidence of active bleeding, but still had rebleed rates of between 3%–11%. Clear documentation of rebleed plans initially was poor, but was better in those with endoscopic signs of active bleeding. Following focused education, rebleed plans improved substantially overall from 23.1% to 46.3%, particularly in those with active bleeding from 47.6% to 77.8%, who had a higher risk of rebleeding and in-hospital mortality.Reference. McPherson SJ, et al. Time to get Control; NCEPOD report 2015. Disclosure of InterestNone Declared
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