1,583 research outputs found
The genetic basis for adaptation of model-designed syntrophic co-cultures.
Understanding the fundamental characteristics of microbial communities could have far reaching implications for human health and applied biotechnology. Despite this, much is still unknown regarding the genetic basis and evolutionary strategies underlying the formation of viable synthetic communities. By pairing auxotrophic mutants in co-culture, it has been demonstrated that viable nascent E. coli communities can be established where the mutant strains are metabolically coupled. A novel algorithm, OptAux, was constructed to design 61 unique multi-knockout E. coli auxotrophic strains that require significant metabolite uptake to grow. These predicted knockouts included a diverse set of novel non-specific auxotrophs that result from inhibition of major biosynthetic subsystems. Three OptAux predicted non-specific auxotrophic strains-with diverse metabolic deficiencies-were co-cultured with an L-histidine auxotroph and optimized via adaptive laboratory evolution (ALE). Time-course sequencing revealed the genetic changes employed by each strain to achieve higher community growth rates and provided insight into mechanisms for adapting to the syntrophic niche. A community model of metabolism and gene expression was utilized to predict the relative community composition and fundamental characteristics of the evolved communities. This work presents new insight into the genetic strategies underlying viable nascent community formation and a cutting-edge computational method to elucidate metabolic changes that empower the creation of cooperative communities
Quasiparticle interfacial level alignment of highly hybridized frontier levels: HO on TiO(110)
Knowledge of the frontier levels' alignment prior to photo-irradiation is
necessary to achieve a complete quantitative description of HO
photocatalysis on TiO(110). Although HO on rutile TiO(110) has been
thoroughly studied both experimentally and theoretically, a quantitative value
for the energy of the highest HO occupied levels is still lacking. For
experiment, this is due to the HO levels being obscured by hybridization
with TiO(110) levels in the difference spectra obtained via ultraviolet
photoemission spectroscopy (UPS). For theory, this is due to inherent
difficulties in properly describing many-body effects at the
HO-TiO(110) interface. Using the projected density of states (DOS) from
state-of-the-art quasiparticle (QP) , we disentangle the adsorbate and
surface contributions to the complex UPS spectra of HO on TiO(110). We
perform this separation as a function of HO coverage and dissociation on
stoichiometric and reduced surfaces. Due to hybridization with the TiO(110)
surface, the HO 3a and 1b levels are broadened into several peaks
between 5 and 1 eV below the TiO(110) valence band maximum (VBM). These
peaks have both intermolecular and interfacial bonding and antibonding
character. We find the highest occupied levels of HO adsorbed intact and
dissociated on stoichiometric TiO(110) are 1.1 and 0.9 eV below the VBM. We
also find a similar energy of 1.1 eV for the highest occupied levels of HO
when adsorbed dissociatively on a bridging O vacancy of the reduced surface. In
both cases, these energies are significantly higher (by 0.6 to 2.6 eV) than
those estimated from UPS difference spectra, which are inconclusive in this
energy region. Finally, we apply self-consistent QP (scQP1) to obtain
the ionization potential of the HO-TiO(110) interface.Comment: 12 pages, 12 figures, 1 tabl
Reliability and sensitivity to change of the bristol rheumatoid arthritis fatigue scales
Objective. To examine the reliability (stability) and sensitivity of the Bristol Rheumatoid Arthritis Fatigue scales (BRAFs) and patient-reported outcome measures (PROMs) developed to capture the fatigue experience. The Multi-Dimensional Questionnaire (BRAF-MDQ) has a global score and four subscales (Physical Fatigue, Living with Fatigue, Cognitive Fatigue and Emotional Fatigue), while three numerical rating scales (BRAF-NRS) measure fatigue Severity, Effect and Coping. Methods. RA patients completed the BRAFs plus comparator PROMs. Reliability (study 1): 50 patients completed questionnaires twice. A same-day test-retest interval (minimum 60 min) ensured both time points related to the same 7 days, minimizing the capture of fatigue fluctuations. Reliability (study 2): 50 patients completed the same procedure with a re-worded BRAF-NRS Coping. Sensitivity to change (study 3): 42 patients being given clinically a single high dose of i.m. glucocorticoids completed questionnaires at weeks 0 and 2.Results. The BRAF-MDQ, its subscales and the BRAF-NRS showed very strong reliability (r = 0.82-0.95). BRAF-NRS Coping had lower moderate reliability in both wording formats (r = 0.62, 0.60). The BRAF-MDQ, its subscales and the BRAF-NRS Severity and Effect were sensitive to change, with effect sizes (ESs) of 0.33-0.56. As hypothesized, the BRF-NRS Coping was not responsive to the pharmaceutical intervention (ES 0.05). Preliminary exploration suggests a minimum clinically important difference of 17.5% for improvement and 6.1% for fatigue worsening. Conclusion. The BRAF scales show good reliability and sensitivity to change. The lack of BRAF-NRS Coping responsiveness to medication supports the theory that coping with fatigue is a concept distinct from severity and effect that is worth measuring separately. © The Author 2013. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing
International audienceCurrent sampling of genomic sequence data from eukaryotes is relatively poor, biased, and inadequate to address important questions about their biology, evolution, and ecology; this Community Page describes a resource of 700 transcriptomes from marine microbial eukaryotes to help understand their role in the world's oceans
The sustainable materials roadmap
Over the past 150 years, our ability to produce and transform engineered materials has been responsible for our current high standards of living, especially in developed economies. However, we must carefully think of the effects our addiction to creating and using materials at this fast rate will have on the future generations. The way we currently make and use materials detrimentally affects the planet Earth, creating many severe environmental problems. It affects the next generations by putting in danger the future of the economy, energy, and climate. We are at the point where something must drastically change, and it must change now. We must create more sustainable materials alternatives using natural raw materials and inspiration from nature while making sure not to deplete important resources, i.e. in competition with the food chain supply. We must use less materials, eliminate the use of toxic materials and create a circular materials economy where reuse and recycle are priorities. We must develop sustainable methods for materials recycling and encourage design for disassembly. We must look across the whole materials life cycle from raw resources till end of life and apply thorough life cycle assessments (LCAs) based on reliable and relevant data to quantify sustainability. We need to seriously start thinking of where our future materials will come from and how could we track them, given that we are confronted with resource scarcity and geographical constrains. This is particularly important for the development of new and sustainable energy technologies, key to our transition to net zero. Currently 'critical materials' are central components of sustainable energy systems because they are the best performing. A few examples include the permanent magnets based on rare earth metals (Dy, Nd, Pr) used in wind turbines, Li and Co in Li-ion batteries, Pt and Ir in fuel cells and electrolysers, Si in solar cells just to mention a few. These materials are classified as 'critical' by the European Union and Department of Energy. Except in sustainable energy, materials are also key components in packaging, construction, and textile industry along with many other industrial sectors. This roadmap authored by prominent researchers working across disciplines in the very important field of sustainable materials is intended to highlight the outstanding issues that must be addressed and provide an insight into the pathways towards solving them adopted by the sustainable materials community. In compiling this roadmap, we hope to aid the development of the wider sustainable materials research community, providing a guide for academia, industry, government, and funding agencies in this critically important and rapidly developing research space which is key to future sustainability.journal articl
Perinatal HIV transmission and the cost-effectiveness of screening at 14 weeks gestation, at the onset of labour and the rapid testing of infants
<p>Abstract</p> <p>Background</p> <p>Preventing HIV transmission is a worldwide public health issue. Vertical transmission of HIV from a mother can be prevented with diagnosis and treatment, but screening incurs cost. The U.S. Virgin Islands follows the mainland policy on antenatal screening for HIV even though HIV prevalence is higher and rates of antenatal care are lower. This leads to many cases of vertically transmitted HIV. A better policy is required for the U.S. Virgin Islands.</p> <p>Methods</p> <p>The objective of this research was to estimate the cost-effectiveness of relevant HIV screening strategies for the antenatal population in the U.S. Virgin Islands. An economic model was used to evaluate the incremental costs and incremental health benefits of nine different combinations of perinatal HIV screening strategies as compared to existing practice from a societal perspective. Three opportunities for screening were considered in isolation and in combination: by 14 weeks gestation, at the onset of labor, or of the infant after birth. The main outcome measure was the cost per life year gained (LYG).</p> <p>Results</p> <p>Results indicate that all strategies would produce benefits and save costs. Universal screening by 14 weeks gestation and screening the infant after birth is the recommended strategy, with cost savings of $1,122,787 and health benefits of 310 LYG. Limitations include the limited research on the variations in screening acceptance of screening based on specimen sample, race and economic status. The benefits of screening after 14 weeks gestation but before the onset of labor were also not addressed.</p> <p>Conclusion</p> <p>This study highlights the benefits of offering screening at different opportunities and repeat screening and raises the question of generalizing these results to other countries with similar characteristics.</p
Report of the Topical Group on Electroweak Precision Physics and Constraining New Physics for Snowmass 2021
The precise measurement of physics observables and the test of their
consistency within the standard model (SM) are an invaluable approach,
complemented by direct searches for new particles, to determine the existence
of physics beyond the standard model (BSM). Studies of massive electroweak
gauge bosons (W and Z bosons) are a promising target for indirect BSM searches,
since the interactions of photons and gluons are strongly constrained by the
unbroken gauge symmetries. They can be divided into two categories: (a) Fermion
scattering processes mediated by s- or t-channel W/Z bosons, also known as
electroweak precision measurements; and (b) multi-boson processes, which
include production of two or more vector bosons in fermion-antifermion
annihilation, as well as vector boson scattering (VBS) processes. The latter
categories can test modifications of gauge-boson self-interactions, and the
sensitivity is typically improved with increased collision energy.
This report evaluates the achievable precision of a range of future
experiments, which depend on the statistics of the collected data sample, the
experimental and theoretical systematic uncertainties, and their correlations.
In addition it presents a combined interpretation of these results, together
with similar studies in the Higgs and top sector, in the Standard Model
effective field theory (SMEFT) framework. This framework provides a
model-independent prescription to put generic constraints on new physics and to
study and combine large sets of experimental observables, assuming that the new
physics scales are significantly higher than the EW scale.Comment: 55 pages; Report of the EF04 topical group for Snowmass 202
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