155 research outputs found
Mangrove microniches determine the structural and functional diversity of enriched petroleum hydrocarbon-degrading consortia
In this study, the combination of culture enrichments and molecular tools was used to identify bacterial guilds, plasmids and functional genes potentially important in the process of petroleum hydrocarbon (PH) decontamination in mangrove microniches (rhizospheres and bulk sediment). In addition, we aimed to recover PH-degrading consortia (PHDC) for future use in remediation strategies. The PHDC were enriched with petroleum from rhizosphere and bulk sediment samples taken from a mangrove chronically polluted with oil hydrocarbons. Southern blot hybridization (SBH) assays of PCR amplicons from environmental DNA before enrichments resulted in weak positive signals for the functional gene types targeted, suggesting that PH-degrading genotypes and plasmids were in low abundance in the rhizosphere and bulk sediments. However, after enrichment, these genes were detected and strong microniche-dependent differences in the abundance and composition of hydrocarbonoclastic bacterial populations, plasmids (IncP-1 alpha, IncP-1 beta, IncP-7 and IncP-9) and functional genes (naphthalene, extradiol and intradiol dioxygenases) were revealed by in-depth molecular analyses [PCR-denaturing gradient gel electrophoresis and hybridization (SBH and microarray)]. Our results suggest that, despite the low abundance of PH-degrading genes and plasmids in the environmental samples, the original bacterial composition of the mangrove microniches determined the structural and functional diversity of the PHDC enriched.Deutsche Forschungsgemeinschaft [SM59/4-1, 4-2]; FAPERJ-Brazil; European Commission [003998, 211684]; Alexander-von-Humboldt-Stiftung; CONICET (Argentina)info:eu-repo/semantics/publishedVersio
Weak-strong uniqueness property for the full Navier-Stokes-Fourier system
The Navier-Stokes-Fourier system describing the motion of a compressible,
viscous, and heat conducting fluid is known to possess global-in-time weak
solutions for any initial data of finite energy. We show that a weak solution
coincides with the strong solution, emanating from the same initial data, as
long as the latter exists. In particular, strong solutions are unique within
the class of weak solutions
Psychometrics of the patient-reported outcomes measurement information system measures in hemophilia:the applicability of the pediatric item banks
Background: The use of patient-reported outcomes measures (PROMs) is important in hemophilia care, as it facilitates communication between patients and clinicians and promotes patient-centered care. Currently, a variety of PROMs with insufficient psychometric properties are used. Patient-reported outcomes measurement information system (PROMIS) measures, including Computer Adaptive Tests, were designed to measure generically and more efficiently and, therefore, are an alternative for the existing PROMs. Objectives: To assess the feasibility, measurement properties, and outcomes of 8 PROMIS pediatric measures for boys with hemophilia. Methods: In this multicenter study, boys with hemophilia completed 8 PROMIS measures and 2 legacy instruments. Feasibility was determined by the number of completed items and floor or ceiling effects (percentage of participants that achieved the lowest or highest possible score). Reliability was assessed as the percentage of scores with a SE ≤ 4.5. Construct validity was evaluated by comparing the PROMIS measures with the legacy instruments. Mean PROMIS T-scores were calculated and compared with the Dutch general population. Results: In total, 77 boys with hemophilia participated. Reliability was good for almost all PROMIS measures and legacy instruments. The total number of completed items varied from 49 to 90 for the PROMIS pediatric measures, while the legacy instruments contained 117 to 130 items. Floor and ceiling effects were observed in both the PROMIS measures (0-39.5%) and legacy instruments (0-66.7%), but were higher for the legacy instruments. Conclusions: The PROMIS pediatric measures are feasible to use for boys with hemophilia. With the use of the PROMIS measures in clinical care and research, a step toward worldwide standardization of PROM administration can be taken.</p
Multidimensional Conservation Laws: Overview, Problems, and Perspective
Some of recent important developments are overviewed, several longstanding
open problems are discussed, and a perspective is presented for the
mathematical theory of multidimensional conservation laws. Some basic features
and phenomena of multidimensional hyperbolic conservation laws are revealed,
and some samples of multidimensional systems/models and related important
problems are presented and analyzed with emphasis on the prototypes that have
been solved or may be expected to be solved rigorously at least for some cases.
In particular, multidimensional steady supersonic problems and transonic
problems, shock reflection-diffraction problems, and related effective
nonlinear approaches are analyzed. A theory of divergence-measure vector fields
and related analytical frameworks for the analysis of entropy solutions are
discussed.Comment: 43 pages, 3 figure
An efficient strategy for evaluating new non-invasive screening tests for colorectal cancer: the guiding principles.
New screening tests for colorectal cancer (CRC) are rapidly emerging. Conducting trials with mortality reduction as the end point supporting their adoption is challenging. We re-examined the principles underlying evaluation of new non-invasive tests in view of technological developments and identification of new biomarkers.
A formal consensus approach involving a multidisciplinary expert panel revised eight previously established principles.
Twelve newly stated principles emerged. Effectiveness of a new test can be evaluated by comparison with a proven comparator non-invasive test. The faecal immunochemical test is now considered the appropriate comparator, while colonoscopy remains the diagnostic standard. For a new test to be able to meet differing screening goals and regulatory requirements, flexibility to adjust its positivity threshold is desirable. A rigorous and efficient four-phased approach is proposed, commencing with small studies assessing the test's ability to discriminate between CRC and non-cancer states (phase I), followed by prospective estimation of accuracy across the continuum of neoplastic lesions in neoplasia-enriched populations (phase II). If these show promise, a provisional test positivity threshold is set before evaluation in typical screening populations. Phase III prospective studies determine single round intention-to-screen programme outcomes and confirm the test positivity threshold. Phase IV studies involve evaluation over repeated screening rounds with monitoring for missed lesions. Phases III and IV findings will provide the real-world data required to model test impact on CRC mortality and incidence.
New non-invasive tests can be efficiently evaluated by a rigorous phased comparative approach, generating data from unbiased populations that inform predictions of their health impact
Psychometrics of the patient-reported outcomes measurement information system measures in hemophilia: the applicability of the pediatric item banks
Background: The use of patient-reported outcomes measures (PROMs) is important in hemophilia care, as it facilitates communication between patients and clinicians and promotes patient-centered care. Currently, a variety of PROMs with insufficient psychometric properties are used. Patient-reported outcomes measurement information system (PROMIS) measures, including Computer Adaptive Tests, were designed to measure generically and more efficiently and, therefore, are an alternative for the existing PROMs. Objectives: To assess the feasibility, measurement properties, and outcomes of 8 PROMIS pediatric measures for boys with hemophilia. Methods: In this multicenter study, boys with hemophilia completed 8 PROMIS measures and 2 legacy instruments. Feasibility was determined by the number of completed items and floor or ceiling effects (percentage of participants that achieved the lowest or highest possible score). Reliability was assessed as the percentage of scores with a SE ≤ 4.5. Construct validity was evaluated by comparing the PROMIS measures with the legacy instruments. Mean PROMIS T-scores were calculated and compared with the Dutch general population. Results: In total, 77 boys with hemophilia participated. Reliability was good for almost all PROMIS measures and legacy instruments. The total number of completed items varied from 49 to 90 for the PROMIS pediatric measures, while the legacy instruments contained 117 to 130 items. Floor and ceiling effects were observed in both the PROMIS measures (0-39.5%) and legacy instruments (0-66.7%), but were higher for the legacy instruments. Conclusions: The PROMIS pediatric measures are feasible to use for boys with hemophilia. With the use of the PROMIS measures in clinical care and research, a step toward worldwide standardization of PROM administration can be taken
Search for Nova Presolar Grains: γ -Ray Spectroscopy of Ar 34 and its Relevance for the Astrophysical Cl 33 (p,γ) Reaction
The discovery of presolar grains in primitive meteorites has initiated a new era of research in the study of stellar nucleosynthesis. However, the accurate classification of presolar grains as being of specific stellar origins is particularly challenging. Recently, it has been suggested that sulfur isotopic abundances may hold the key to definitively identifying presolar grains with being of nova origins and, in this regard, the astrophysical Cl33(p,γ)Ar34 reaction is expected to play a decisive role. As such, we have performed a detailed γ-ray spectroscopy study of Ar34. Excitation energies have been measured with high precision and spin-parity assignments for resonant states, located above the proton threshold in Ar34, have been made for the first time. Uncertainties in the Cl33(p,γ) reaction have been dramatically reduced and the results indicate that a newly identified ℓ =0 resonance at Er=396.9(13) keV dominates the entire rate for T=0.25-0.40 GK. Furthermore, nova hydrodynamic simulations based on the present work indicate an ejected S32/S33 abundance ratio distinctive from type-II supernovae and potentially compatible with recent measurements of a presolar grain
Level structure of the Tz=-1 nucleus Ar 34 and its relevance for nucleosynthesis in ONe novae
The Mg24+C12 fusion reaction was used to perform a detailed γ-ray spectroscopy study of the astrophysically important nucleus Ar34. In particular, an experimental setup, coupling the advanced γ-ray tracking array GRETINA with the well-established Argonne fragment mass analyzer (FMA), was employed to obtain excitation energies and spin-parity assignments for excited states in Ar34, both above and below the proton separation energy. For the first time, an angular distribution analysis of in-beam γ rays from fusion-evaporation reactions, using a tracking array, has been performed and Coulomb energy differences of analog states in the T=1, A=34 mirror system, explored from 0 to 6 MeV. Furthermore, we present a comprehensive discussion of the astrophysical Cl33(p,γ) stellar reaction rate, together with implications for the identification of nova presolar grains from sulfur isotopic abundances
Projected WIMP sensitivity of the LUX-ZEPLIN dark matter experiment
LUX-ZEPLIN (LZ) is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with weakly interacting massive particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6-tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above 1.4 × 10-48cm2 for a 40 GeV/c2 mass WIMP.
Additionally, a 5σ discovery potential is projected, reaching cross sections below the exclusion limits of recent experiments. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of 2.3 × 10−43 cm2 (7.1 × 10−42 cm2) for a 40 GeV/c2
mass WIMP is expected. With underground installation well underway, LZ is on track for commissioning at SURF in 2020
COVAD survey 2 long-term outcomes: unmet need and protocol
Vaccine hesitancy is considered a major barrier to achieving herd immunity against COVID-19. While multiple alternative and synergistic approaches including heterologous vaccination, booster doses, and antiviral drugs have been developed, equitable vaccine uptake remains the foremost strategy to manage pandemic. Although none of the currently approved vaccines are live-attenuated, several reports of disease flares, waning protection, and acute-onset syndromes have emerged as short-term adverse events after vaccination. Hence, scientific literature falls short when discussing potential long-term effects in vulnerable cohorts. The COVAD-2 survey follows on from the baseline COVAD-1 survey with the aim to collect patient-reported data on the long-term safety and tolerability of COVID-19 vaccines in immune modulation. The e-survey has been extensively pilot-tested and validated with translations into multiple languages. Anticipated results will help improve vaccination efforts and reduce the imminent risks of COVID-19 infection, especially in understudied vulnerable groups
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