244 research outputs found
A regulatory framework for cryptocurrency
This is the final version. Available from Kluwer Law International via the link in this recordThe paper examines cryptocurrency in the crypto-finance ecosystem and identifies areas in
which regulatory intervention is required. Part I focuses on the system and processes of
cryptocurrency and identifies the features of this âdecentralisedâ system and the legal and
regulatory implications. Part II discusses the perceived benefits and the rise of cryptocurrency
to determine whether those benefits fit with regulatory objectives and contribute to the rise of
cryptocurrency. Part III discusses the fall of cryptocurrency and some associated factors,
particularly a lack of governance. Part IV discusses the need for regulation and governance
Motility defects in Campylobacter jejuni defined gene deletion mutants caused by second-site mutations.
Genetic variation due to mutation and phase variation has a considerable impact on the commensal and pathogenic behaviours of Campylobacter jejuni. In this study, we provide an example of how second-site mutations can interfere with gene function analysis in C. jejuni. Deletion of the flagellin B gene (flaB) in C. jejuni M1 resulted in mutant clones with inconsistent motility phenotypes. From the flaB mutant clones picked for further analysis, two were motile, one showed intermediate motility and two displayed severely attenuated motility. To determine the molecular basis of this differential motility, a genome resequencing approach was used. Second-site mutations were identified in the severely attenuated and intermediate motility flaB mutant clones: a TA-dinucleotide deletion in fliW and an A deletion in flgD, respectively. Restoration of WT fliW, using a newly developed genetic complementation system, confirmed that the second-site fliW mutation caused the motility defect as opposed to the primary deletion of flaB. This study highlights the importance of (i) screening multiple defined gene deletion mutant clones, (ii) genetic complementation of the gene deletion and ideally (iii) screening for second-site mutations that might interfere with the pathways/mechanisms under study.This work was funded by BBSRC grant RG66581.This is the final version of the article. It was first available from Society for General Microbiology via http://dx.doi.org/10.1099/mic.0.00018
Space-time Structure of Initial Parton Production in Ultrarelativistic Heavy Ion Collisions
The space and time evolution of initial parton production in
ultrarelativistic heavy ion collisions is investigated within the framework of
perturbative QCD which includes both initial and final state radiations.
Uncertainty principle is used to relate the life time of a radiating parton to
its virtuality and momentum. The interaction time of each hard or semihard
parton scattering is also taken into account. For central collisions at
GeV, most of the partons are found to be produced within 0.5
fm/c after the total overlap of the two colliding nuclei. The local momentum
distribution is approximately isotropical at that time. The implication on how
to treat correctly the the secondary scattering in an ultimate parton cascading
model is also discussed.Comment: 19 pages in REVTEX with 12 figures in separate uuencoded postscript
files, LBL-3415
Studying minijets via the dependence of two-particle correlation in azimuthal angle
Following my previous proposal that two-particle correlation functions can be
used to resolve the minijet contribution to particle production in minimum
biased events of high energy hadronic interactions, I study the and
energy dependence of the correlation. Using HIJING Monte Carlo model, it is
found that the correlation in azimuthal angle between
two particles with resembles much like two back-to-back jets as
increases at high colliding energies due to minijet production. It
is shown that , which is related to the relative fraction of
particles from minijets, increases with energy. The background of the
correlation for fixed also grows with energy due to the increase of
multiple minijet production. Application of this analysis to the study of jet
quenching in ultrarelativistic heavy ion collisions is also discussed.Comment: 11 pages Latex text and 8 ps figures, LBL-3349
Provider confidence in counseling preconception, pregnant, and postpartum patients regarding COVIDâ19 vaccination: A crossâsectional survey study
Background and Aims Healthcare provider counseling surrounding COVIDâ19 vaccine in pregnancy and lactation is essential to vaccination uptake in this population; however, provider knowledge and confidence are not well characterized. We aimed to assess knowledge and confidence in COVIDâ19 vaccine counseling among practitioners who provide care to pregnant persons and to describe factors associated with confidence in counseling. Methods A webâbased anonymous survey was distributed via email to a crossâsectional convenience sample of Obstetrics and Gynecology, Primary Care, and Internal Medicine faculty at three hospitals in a single healthcare network in Massachusetts, United States. Individual demographics and institutionâspecific variables were included in the survey along with questions assessing both attitudes toward COVIDâ19 illness and confidence in counseling regarding the use of the vaccine in pregnancy. Results Almost all providers (151, 98.1%) reported that they received a COVIDâ19 vaccine, and most (111, 72.1%) reported that they believe the benefits of the vaccine in pregnancy outweigh the risks. Fortyâone (26.6%) reported feeling very confident in counseling patients who primarily speak English about the evidence for messenger ribonucleic acid vaccination in pregnancy, and 36 (23%) reported feeling very confident in counseling patients who are not primarily Englishâspeaking. Fortyâthree providers (28.1%) expressed strong confidence in their comfort talking to individuals with vaccine hesitancy based on historic and continued racism and systemic injustices. The sources that survey respondents most used to find information regarding COVIDâ19 vaccination in pregnancy were the Centers for Disease Control (112, 74.2%), hospitalâspecific resources (94, 62.3%), and the American College of Obstetricians and Gynecologists (82, 54.3%). Conclusion Ensuring that providers feel comfortable bridging the gap between their belief that the vaccine is beneficial for pregnant patients and their comfort with holding conversations with patients regarding vaccination is paramount to ensure equitable access to vaccines for pregnant patients
Tropical influence independent of ENSO on the austral summer Southern Annular Mode
A link between atmospheric variability in the Tropics independent of ENSO and the Southern Annular Mode (SAM) is found based on seasonal mean data for austral summer. Variations associated with El Niño Southern Oscillation (ENSO) are removed usinga linear method and a Tropics Index (TI) is defined as the zonal average of the ENSO-removed 500âhPa geopotential height between 10°S and 10°N. Since the detrended TI shows no link to SST variability in the Tropics, it appears to be related to internal atmospheric variability. We find that the TI can explain about 40% variance of the SAM interannual variability and about 75% of the SAM long term trend between 1957/58 and 2001/02, where here the SAM includes the ENSO signal. Positive/negative values of the TI are associated with the positive/negative SAM. A possible link between the TI and global warming is noted
Endothelial apoptotic activity of angiocidin is dependent on its polyubiquitin binding activity
We recently cloned the full-length cDNA of a tumour-associated protein. The recombinant protein expressed in bacteria and referred to as angiocidin has potent antitumour activity in vivo and in vitro. Angiocidin inhibits tumour growth and angiogenesis by inducing apoptosis in endothelial cells. Based on the sequence similarity of angiocidin to S5a, one of the major polyubiquitin recognition proteins in eukaryotic cells, we postulated that the antiendothelial activity of angiocidin could be due in part to its polyubiquitin binding activity. In support of this hypothesis, we show that angiocidin binds polyubiquitin in vivo with high affinity and colocalises with ubiquitinated proteins on the surface of endothelial cells. Binding is blocked with an antiubiquitin antibody. Angiocidin treatment of endothelial cells transfected with a proteasome fluorescent reporter protein showed a dose-dependent inhibition of proteasome activity and accumulation of polyubiquitinated proteins. Full-length angiocidin bound polyubiquitin while three angiocidin recombinant proteins whose putative polyubiquitin binding sites were mutated either failed to bind polyubiquitin or had significantly diminished binding activity. The in vitro apoptotic activity of these mutants correlated with their polyubiquitin binding activity. These data strongly argue that the apoptotic activity of angiocidin is dependent on its polyubiquitin binding activity
Multiple Interactions and the Structure of Beam Remnants
Recent experimental data have established some of the basic features of
multiple interactions in hadron-hadron collisions. The emphasis is therefore
now shifting, to one of exploring more detailed aspects. Starting from a brief
review of the current situation, a next-generation model is developed, wherein
a detailed account is given of correlated flavour, colour, longitudinal and
transverse momentum distributions, encompassing both the partons initiating
perturbative interactions and the partons left in the beam remnants. Some of
the main features are illustrated for the Tevatron and the LHC.Comment: 69pp, 33 figure
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