787 research outputs found
The Effect of Doping Process Route on LiNiO Cathode Material Properties
The pursuit of higher energy density in lithium-ion batteries has driven the increase of the nickel content in lithium nickel cobalt manganese oxide cathode active materials (CAMs), ultimately approaching LiNiO (LNO). The downside of the high specific capacity of LNO is more severe degradation of the CAM during battery operation. A common approach to increase structural stability is the introduction of dopants. Various dopants are discussed and compared with each other when integrated into the CAM and tested against undoped materials in the literature, but little attention is given to the role of the process route of their introduction. In this work, we demonstrate with a series of nominally equally Zr-doped LNO samples that effects on various physico- and electrochemical properties are due not to the dopant itself, as one would assume in comparison to an undoped sample, but to the process route and the resulting particle morphology. Dopant, concentration and process routes (co-precipitation, impregnation and co-calcination) were chosen based on their significance for industrial application
Oscillations and interactions of dark and dark-bright solitons in Bose-Einstein condensates
Solitons are among the most distinguishing fundamental excitations in a wide
range of non-linear systems such as water in narrow channels, high speed
optical communication, molecular biology and astrophysics. Stabilized by a
balance between spreading and focusing, solitons are wavepackets, which share
some exceptional generic features like form-stability and particle-like
properties. Ultra-cold quantum gases represent very pure and well-controlled
non-linear systems, therefore offering unique possibilities to study soliton
dynamics. Here we report on the first observation of long-lived dark and
dark-bright solitons with lifetimes of up to several seconds as well as their
dynamics in highly stable optically trapped Rb Bose-Einstein
condensates. In particular, our detailed studies of dark and dark-bright
soliton oscillations reveal the particle-like nature of these collective
excitations for the first time. In addition, we discuss the collision between
these two types of solitary excitations in Bose-Einstein condensates.Comment: 9 pages, 4 figure
Mixed methods instrument validation: Evaluation procedures for practitioners developed from the validation of the Swiss Instrument for Evaluating Interprofessional Collaboration.
BACKGROUND
Quantitative and qualitative procedures are necessary components of instrument development and assessment. However, validation studies conventionally emphasise quantitative assessments while neglecting qualitative procedures. Applying both methods in a mixed methods design provides additional insights into instrument quality and more rigorous validity evidence. Drawing from an extensive review of the methodological and applied validation literature on mixed methods, we showcase our use of mixed methods for validation which applied the quality criteria of congruence, convergence, and credibility on data collected with an instrument measuring interprofessional collaboration in the context of Swiss healthcare, named the Swiss Instrument for Evaluating Interprofessional Collaboration.
METHODS
We employ a convergent parallel mixed methods design to analyse quantitative and qualitative questionnaire data. Data were collected from staff, supervisors, and patients of a university hospital and regional hospitals in the German and Italian speaking regions of Switzerland. We compare quantitative ratings and qualitative comments to evaluate the quality criteria of congruence, convergence, and credibility, which together form part of an instrument's construct validity evidence.
RESULTS
Questionnaires from 435 staff, 133 supervisors, and 189 patients were collected. Analysis of congruence potentially provides explanations why respondents' comments are off topic. Convergence between quantitative ratings and qualitative comments can be interpreted as an indication of convergent validity. Credibility provides a summary evaluation of instrument quality. These quality criteria provide evidence that questions were understood as intended, provide construct validity, and also point to potential item quality issues.
CONCLUSIONS
Mixed methods provide alternative means of collecting construct validity evidence. Our suggested procedures can be easily applied on empirical data and allow the congruence, convergence, and credibility of questionnaire items to be evaluated. The described procedures provide an efficient means of enhancing the rigor of an instrument and can be used alone or in conjunction with traditional quantitative psychometric approaches
Comparison of community-wide, integrated mass drug administration strategies for schistosomiasis and soil-transmitted helminthiasis: a cost-eff ectiveness modelling study
Background More than 1·5 billion people are aff ected by schistosomiasis or soil-transmitted helminthiasis. WHO’s
recommendations for mass drug administration (MDA) against these parasitic infections emphasise treatment of
school-aged children, using separate treatment guidelines for these two helminthiases groups. We aimed to evaluate
the cost-eff ectiveness of expanding integrated MDA to the entire community in four settings in Côte d’Ivoire.
Methods We extended previously published, dynamic, age-structured models of helminthiases transmission to
simulate costs and disability averted with integrated MDA (of praziquantel and albendazole) for schistosomiasis and
soil-transmitted helminthiasis. We calibrated the model to data for prevalence and intensity of species-specifi c
helminth infection from surveys undertaken in four communities in Côte d’Ivoire between March, 1997,
and September, 2010. We simulated a 15-year treatment programme with 75% coverage in only school-aged children;
school-aged children and preschool-aged children; adults; and the entire community. Treatment costs were estimated
at US1·74 for preschool-aged children and adults. The incremental costeff
ectiveness ratio (ICER) was calculated in 2014 US dollars per disability-adjusted life-year (DALY) averted.
Findings Expanded community-wide treatment was highly cost eff ective compared with treatment of only school-aged
children (ICER 127 per DALY averted), and remained highly
cost eff ective even if treatment costs for preschool-aged children and adults were ten times greater than those for
school-aged children. Community-wide treatment remained highly cost eff ective even when elimination of helminth
infections was not achieved. These fi ndings were robust across the four diverse communities in Côte d’Ivoire, only
one of which would have received annual MDA for both schistosomiasis and soil-transmitted helminthiasis under
the latest WHO guidelines. Treatment every 6 months was also highly cost eff ective in three out of four communities.
Interpretation Integrated, community-wide MDA programmes for schistosomiasis and soil-transmitted helminthiasis
can be highly cost eff ective, even in communities with low disease burden in any helminth group. These results
support an urgent need to re-evaluate current global guidelines for helminthiases control programmes to include
community-wide treatment, increased treatment frequency, and consideration for lowered prevalence thresholds for
integrated treatment
Soil-derived Nature’s Contributions to People and their contribution to the UN Sustainable Development Goals
Acknowledgments The input of PS contributes to Soils-R-GRREAT (NE/P019455/1) and the input of PS and SK contributes to the European Union's Horizon 2020 Research and Innovation Programme through project CIRCASA (grant agreement no. 774378). PR acknowledges funding from UK Greenhouse Gas Removal Programme (NE/P01982X/2). GB De Deyn acknowledges FoodShot Global for its support. TKA acknowledges the support of “Towards Integrated Nitrogen Management System (INMS) funded by the Global Environment Facility (GEF), executed through the UK’s Natural Environment Research Council (NERC). The input of DG was supported by the New Zealand Ministry of Business, Innovation and Employment (MBIE) strategic science investment fund (SSIF). PMS acknowledges support from the Australian Research Council (Project FT140100610). PM’s work on ecosystem services is supported by a National Science Foundation grant #1853759, “Understanding the Use of Ecosystem Services Concepts in Environmental Policy”. LGC is funded by National Council for Scientific and Technological Development (CNPq, Brazil – grants 421668/2018-0 and 305157/2018-3) and by Lisboa2020 FCT/EU (project 028360). BS acknowledges support from the Lancaster Environment Centre Project.Peer reviewedPostprin
Flavor Physics in an SO(10) Grand Unified Model
In supersymmetric grand-unified models, the lepton mixing matrix can possibly
affect flavor-changing transitions in the quark sector. We present a detailed
analysis of a model proposed by Chang, Masiero and Murayama, in which the
near-maximal atmospheric neutrino mixing angle governs large new b -> s
transitions. Relating the supersymmetric low-energy parameters to seven new
parameters of this SO(10) GUT model, we perform a correlated study of several
flavor-changing neutral current (FCNC) processes. We find the current bound on
B(tau -> mu gamma) more constraining than B(B -> X_s gamma). The LEP limit on
the lightest Higgs boson mass implies an important lower bound on tan beta,
which in turn limits the size of the new FCNC transitions. Remarkably, the
combined analysis does not rule out large effects in B_s-B_s-bar mixing and we
can easily accomodate the large CP phase in the B_s-B_s-bar system which has
recently been inferred from a global analysis of CDF and DO data. The model
predicts a particle spectrum which is different from the popular Constrained
Minimal Supersymmetric Standard Model (CMSSM). B(tau -> mu gamma) enforces
heavy masses, typically above 1 TeV, for the sfermions of the degenerate first
two generations. However, the ratio of the third-generation and
first-generation sfermion masses is smaller than in the CMSSM and a (dominantly
right-handed) stop with mass below 500 GeV is possible.Comment: 44 pages, 5 figures. Footnote and references added, minor changes,
Fig. 2 corrected; journal versio
Lepton flavour violation in the MSSM
We derive new constraints on the quantities delta_{XY}^{ij}, X,Y=L,R, which
parametrise the flavour-off-diagonal terms of the charged slepton mass matrix
in the MSSM. Considering mass and anomalous magnetic moment of the electron we
obtain the bound |delta^{13}_{LL} delta^{13}_{RR}|<0.1 for tan beta=50, which
involves the poorly constrained element delta^{13}_{RR}. We improve the
predictions for the decays tau -> mu gamma, tau -> e gamma and mu -> e gamma by
including two-loop corrections which are enhanced if tan beta is large. The
finite renormalisation of the PMNS matrix from soft SUSY-breaking terms is
derived and applied to the charged-Higgs-lepton vertex. We find that the
experimental bound on BR(tau -> e gamma) severely limits the size of the MSSM
loop correction to the PMNS element U_{e3}, which is important for the proper
interpretation of a future U_{e3} measurement. Subsequently we confront our new
values for delta^{ij}_{LL} with a GUT analysis. Further, we include the effects
of dimension-5 Yukawa terms, which are needed to fix the Yukawa unification of
the first two generations. If universal supersymmetry breaking occurs above the
GUT scale, we find the flavour structure of the dimension-5 Yukawa couplings
tightly constrained by mu -> e gamma.Comment: 37 pages, 15 figures; typo in Equation (35) and (49) correcte
Pion interferometry in Au+Au collisions at sqrt[sNN]=200GeV
We present a systematic analysis of two-pion interferometry in Au+Au collisions at sqrt[sNN]=200GeV using the STAR detector at Relativistic Heavy Ion Collider. We extract the Hanbury-Brown and Twiss radii and study their multiplicity, transverse momentum, and azimuthal angle dependence. The Gaussianness of the correlation function is studied. Estimates of the geometrical and dynamical structure of the freeze-out source are extracted by fits with blast-wave parametrizations. The expansion of the source and its relation with the initial energy density distribution is studied
Evidence of and search for double-charmonium production in and decays
Using data samples of and
events collected with the Belle detector, a first experimental
search has been made for double-charmonium production in the exclusive decays
, where , , , , and . No significant signal is
observed in the spectra of the mass recoiling against the reconstructed
or except for the evidence of production with a
significance of for . The
measured branching fraction \BR(\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}) is
. The
confidence level upper limits on the branching fractions of the other modes
having a significance of less than are determined. These results are
consistent with theoretical calculations using the nonrelativistic QCD
factorization approach.Comment: 12 pages, 4 figures, 1 table. The fit range was extended to include
X(4160) signal according to referee's suggestions. Other results unchanged.
Paper was accepted for publication as a regular article in Physical Review
Salmonella Transiently Reside in Luminal Neutrophils in the Inflamed Gut
Enteric pathogens need to grow efficiently in the gut lumen in order to cause disease and ensure transmission. The interior of the gut forms a complex environment comprising the mucosal surface area and the inner gut lumen with epithelial cell debris and food particles. Recruitment of neutrophils to the intestinal lumen is a hallmark of non-typhoidal Salmonella enterica infections in humans. Here, we analyzed the interaction of gut luminal neutrophils with S. enterica serovar Typhimurium (S. Tm) in a mouse colitis model.Upon S. Tm(wt) infection, neutrophils transmigrate across the mucosa into the intestinal lumen. We detected a majority of pathogens associated with luminal neutrophils 20 hours after infection. Neutrophils are viable and actively engulf S. Tm, as demonstrated by live microscopy. Using S. Tm mutant strains defective in tissue invasion we show that pathogens are mostly taken up in the gut lumen at the epithelial barrier by luminal neutrophils. In these luminal neutrophils, S. Tm induces expression of genes typically required for its intracellular lifestyle such as siderophore production iroBCDE and the Salmonella pathogenicity island 2 encoded type three secretion system (TTSS-2). This shows that S. Tm at least transiently survives and responds to engulfment by gut luminal neutrophils. Gentamicin protection experiments suggest that the life-span of luminal neutrophils is limited and that S. Tm is subsequently released into the gut lumen. This "fast cycling" through the intracellular compartment of gut luminal neutrophils would explain the high fraction of TTSS-2 and iroBCDE expressing intra- and extracellular bacteria in the lumen of the infected gut.
In conclusion, live neutrophils recruited during acute S. Tm colitis engulf pathogens in the gut lumen and may thus actively engage in shaping the environment of pathogens and commensals in the inflamed gut
- …