405 research outputs found
Influence of Soil and Rain on the Levels of Inorganic Anions in Amaranth Leaves from Selected Parts of Kenya
The aim of this work was to determine the level of inorganic anions (NO3-, Cl-, SO42-, PO43-, F- and I-) in the leaves of two species of amaranth (Amaranthus hypochondriacus and Amaranthus cruentus) planted in Kenya. The mean levels of inorganic anions, nitrate (NO3-), chloride (Cl-), sulphate (SO42-), phosphate (PO43-), fluoride (F-) and iodide (I-), in the soil from four study regions (Kenyatta University (KU), Bureti, Kisii and Elgon) of Kenya were quantitatively determined. The levels were determined using spectrophotometric, potentiometric and titrimetric methods. The mean levels of Cl-, SO42-, PO43-, NO3-, F- and I- in soils ranged from 1146.54 to 2733.31 mg/100 g, 1821.60 to 2185.33 mg/100 g, 828.54 to 1111.36 mg/100 g, 1015.55 to 1910.66 mg/100 g, 66.95 to 79.77 mg/100 g and 8.00 to 12.57 mg/kg respectively. The levels of most anions in leaves of A. hypochondriacus and A. cruentus were not significantly different. The means levels of the anions in leaves of the two species indicated that Cl- ion had range of 503.74 to 673.81 mg/100 g, SO42- 701.61 to 955.17 mg/100 g, PO43 532.36 to 629.46 mg/100 g, NO3- 495.79 to 880.99 mg/100 g, F- 7.22 to 9.67 mg/100 g while I- ranged from 2.54 mg/kg to 5.26 mg/kg dry weight. The levels of all inorganic anions determined were found to be within the allowed daily intake (ADI) values. Based on the results of this study, it is recommended that leaves and grains from both species of amaranthus grown in most regions in Kenya may be consumed for nutritional requirements. The consumption of between 250 g and 300 g of fresh amaranthus leaves is sufficient to provide the required daily intake of all the anions considered in this study for all healthy individuals. Keywords: Amaranth, Anions, Amaranthus, Tonui
Pollen exposure and hospitalization due to asthma exacerbations: daily time series in a European city.
Exposure to pollen can contribute to increased hospital admissions for asthma exacerbation. This study applied an ecological time series analysis to examine associations between atmospheric concentrations of different pollen types and the risk of hospitalization for asthma in London from 2005 to 2011. The analysis examined short-term associations between daily pollen counts and hospital admissions in the presence of seasonal and long-term patterns, and allowed for time lags between exposure and admission. Models were adjusted for temperature, precipitation, humidity, day of week, and air pollutants. Analyses revealed an association between daily counts (continuous) of grass pollen and adult hospital admissions for asthma in London, with a 4-5-day lag. When grass pollen concentrations were categorized into Met Office pollen 'alert' levels, 'very high' days (vs. 'low') were associated with increased admissions 2-5 days later, peaking at an incidence rate ratio of 1.46 (95%, CI 1.20-1.78) at 3 days. Increased admissions were also associated with 'high' versus 'low' pollen days at a 3-day lag. Results from tree pollen models were inconclusive and likely to have been affected by the shorter pollen seasons and consequent limited number of observation days with higher tree pollen concentrations. Future reductions in asthma hospitalizations may be achieved by better understanding of environmental risks, informing improved alert systems and supporting patients to take preventive measures
The Atacama Cosmology Telescope: Two-Season ACTPol Lensing Power Spectrum
We report a measurement of the power spectrum of cosmic microwave background
(CMB) lensing from two seasons of Atacama Cosmology Telescope Polarimeter
(ACTPol) CMB data. The CMB lensing power spectrum is extracted from both
temperature and polarization data using quadratic estimators. We obtain results
that are consistent with the expectation from the best-fit Planck LCDM model
over a range of multipoles L=80-2100, with an amplitude of lensing A_lens =
1.06 +/- 0.15 (stat.) +/- 0.06 (sys.) relative to Planck. Our measurement of
the CMB lensing power spectrum gives sigma_8 Omega_m^0.25 = 0.643 +/- 0.054;
including baryon acoustic oscillation scale data, we constrain the amplitude of
density fluctuations to be sigma_8 = 0.831 +/- 0.053. We also update
constraints on the neutrino mass sum. We verify our lensing measurement with a
number of null tests and systematic checks, finding no evidence of significant
systematic errors. This measurement relies on a small fraction of the ACTPol
data already taken; more precise lensing results can therefore be expected from
the full ACTPol dataset.Comment: 17 pages, 11 figures, to be submitted to Physical Review
Neuroimaging, clinical and life course correlates of normal-appearing white matter integrity in 70-year-olds
We investigate associations between normal-appearing white matter (NAWM) microstructural integrity in cognitively normal ∼70-year-olds and concurrently measured brain health and cognition, demographics, genetics and life course cardiovascular health.
Participants born in the same week in March 1946 (British 1946 Birth cohort) underwent PET-MRI around age 70. Mean standardized NAWM integrity metrics (fractional anisotropy (FA), mean diffusivity (MD), neurite density index (NDI) and orientation dispersion index (ODI)) were derived from diffusion MRI. Linear regression was used to test associations between NAWM metrics and (1) concurrent measures, including whole brain volume, white matter hyperintensity volume (WMHV), PET amyloid and cognition; (2) the influence of demographic and genetic predictors, including sex, childhood cognition, education, socioeconomic position, and genetic risk for Alzheimer’s Disease (APOE-ε4); (3) systolic and diastolic blood pressure and cardiovascular health (FHS-CVS) across adulthood. Sex interactions were tested. Statistical significance included false discovery rate correction (5%).
362 participants met inclusion criteria (mean age 70 years, 49% female). Higher WMHV was associated with lower FA (b=-0.09 [95%CI:-0.11, -0.06] p<0.01), NDI (b=-0.17 [-0.22, -0.12] p<0.01), and higher MD (b=0.14 [-0.10, -0.17] p<0.01); amyloid (in men) was associated with lower FA (b=-0.04 [-0.08, -0.01] p=0.03) and higher MD (b=0.06 [0.01,0.11] p=0.02). FHS-CVS in later-life (age 69) was associated with NAWM [lower FA (b=-0.06 [-0.09, -0.02] p<0.01), NDI (b=-0.10 [-0.17, -0.03] p<0.01), and higher MD (b=0.09 [0.04,0.14] p<0.01). Significant sex interactions (p<0.05) emerged for midlife cardiovascular health (age 53) and NAWM at 70: marginal effect plots demonstrated, in women only, NAWM was associated with higher midlife FHS-CVS (lower FA and NDI), midlife systolic (lower FA, NDI, and higher MD), and diastolic (lower FA and NDI) blood pressure, and greater blood pressure change between 43 and 53 years (lower FA and NDI), independently of WMHV.
In summary, poorer NAWM microstructural integrity in ∼70-year-olds was associated with measures of cerebral small vessel disease, amyloid (in males) and later-life cardiovascular health, demonstrating how NAWM can provide additional information to overt white matter disease. Our findings further show that greater midlife cardiovascular risk and higher blood pressure were associated with poorer NAWM microstructural integrity in females only, suggesting that women’s brains may be more susceptible to the effects of midlife blood pressure and cardiovascular health
Single-cell BCR and transcriptome analysis after influenza infection reveals spatiotemporal dynamics of antigen-specific B cells
B cell responses are critical for antiviral immunity. However, a comprehensive picture of antigen-specific B cell differentiation, clonal proliferation, and dynamics in different organs after infection is lacking. Here, by combining single-cell RNA and B cell receptor (BCR) sequencing of antigen-specific cells in lymph nodes, spleen, and lungs after influenza infection in mice, we identify several germinal center (GC) B cell subpopulations and organ-specific differences that persist over the course of the response. We discover transcriptional differences between memory cells in lungs and lymphoid organs and organ-restricted clonal expansion. Remarkably, we find significant clonal overlap between GC-derived memory and plasma cells. By combining BCR-mutational analyses with monoclonal antibody (mAb) expression and affinity measurements, we find that memory B cells are highly diverse and can be selected from both low- and high-affinity precursors. By linking antigen recognition with transcriptional programming, clonal proliferation, and differentiation, these finding provide important advances in our understanding of antiviral immunity
BVRI Light Curves for 29 Type Ia Supernovae
BVRI light curves are presented for 27 Type Ia supernovae discovered during
the course of the Calan/Tololo Survey and for two other SNe Ia observed during
the same period. Estimates of the maximum light magnitudes in the B, V, and I
bands and the initial decline rate parameter m15(B) are also given.Comment: 17 pages, figures and tables are not included (contact first author
if needed), to appear in the Astronomical Journa
CMB-S4 Science Book, First Edition
This book lays out the scientific goals to be addressed by the
next-generation ground-based cosmic microwave background experiment, CMB-S4,
envisioned to consist of dedicated telescopes at the South Pole, the high
Chilean Atacama plateau and possibly a northern hemisphere site, all equipped
with new superconducting cameras. CMB-S4 will dramatically advance cosmological
studies by crossing critical thresholds in the search for the B-mode
polarization signature of primordial gravitational waves, in the determination
of the number and masses of the neutrinos, in the search for evidence of new
light relics, in constraining the nature of dark energy, and in testing general
relativity on large scales
The Atacama Cosmology Telescope: Two-Season ACTPol Spectra and Parameters
We present the temperature and polarization angular power spectra measured by
the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time
data collected during 2013-14 using two detector arrays at 149 GHz, from 548
deg of sky on the celestial equator. We use these spectra, and the spectra
measured with the MBAC camera on ACT from 2008-10, in combination with Planck
and WMAP data to estimate cosmological parameters from the temperature,
polarization, and temperature-polarization cross-correlations. We find the new
ACTPol data to be consistent with the LCDM model. The ACTPol
temperature-polarization cross-spectrum now provides stronger constraints on
multiple parameters than the ACTPol temperature spectrum, including the baryon
density, the acoustic peak angular scale, and the derived Hubble constant.
Adding the new data to planck temperature data tightens the limits on damping
tail parameters, for example reducing the joint uncertainty on the number of
neutrino species and the primordial helium fraction by 20%.Comment: 23 pages, 25 figure
A Simple Scoring System to Differentiate between Relapse and Re-Infection in Patients with Recurrent Melioidosis
Melioidosis is a serious infectious disease caused by the Gram-negative bacterium, Burkholderia pseudomallei. This organism is present in the environment in areas where melioidosis is endemic (most notably East Asia and Northern Australia), and infection is acquired following bacterial inoculation or inhalation. Despite prolonged oral eradicative treatment, recurrent melioidosis occurs in approximately 10% of survivors of acute melioidosis. Recurrent melioidosis can be caused by relapse (failure of initial eradicative treatment) or re-infection with a new infection. The aim of this study was to develop a simple scoring system to distinguish between re-infection and relapse, since this has implications for antimicrobial treatment of the recurrent episode, but telling the two apart normally requires bacterial genotyping. A prospective study of melioidosis patients in NE Thailand conducted between 1986 and 2005 identified 141 patients with recurrent melioidosis. Of these, 92 patients had relapse and 49 patients had re-infection as confirmed by genotyping techniques. We found that relapse was associated with previous inadequate treatment and shorter time to clinical features of recurrence, while re-infection was associated with renal insufficiency and presentation during the rainy season. A simple scoring index to help distinguish between relapse and re-infection was developed to provide important bedside information where rapid bacterial genotyping is unavailable. Guidelines are provided on how this scoring system could be implemented
The SAMI Galaxy Survey: a statistical approach to an optimal classification of stellar kinematics in galaxy surveys
Large galaxy samples from multi-object IFS surveys now allow for a
statistical analysis of the z~0 galaxy population using resolved kinematics.
However, the improvement in number statistics comes at a cost, with
multi-object IFS survey more severely impacted by the effect of seeing and
lower S/N. We present an analysis of ~1800 galaxies from the SAMI Galaxy Survey
and investigate the spread and overlap in the kinematic distributions of the
spin parameter proxy as a function of stellar mass and
ellipticity. For SAMI data, the distributions of galaxies identified as regular
and non-regular rotators with \textsc{kinemetry} show considerable overlap in
the - diagram. In contrast, visually classified
galaxies (obvious and non-obvious rotators) are better separated in
space, with less overlap of both distributions. Then, we use a
Bayesian mixture model to analyse the observed
- distribution. Below
, a single beta distribution is sufficient
to fit the complete distribution, whereas a second beta
distribution is required above to account
for a population of low- galaxies. While the Bayesian mixture
model presents the cleanest separation of the two kinematic populations, we
find the unique information provided by visual classification of kinematic maps
should not be disregarded in future studies. Applied to mock-observations from
different cosmological simulations, the mixture model also predicts bimodal
distributions, albeit with different positions of the
peaks. Our analysis validates the conclusions from previous
smaller IFS surveys, but also demonstrates the importance of using kinematic
selection criteria that are dictated by the quality of the observed or
simulated data.Comment: 30 pages and 17 figures, accepted for publication in MNRAS. Abstract
abridged for Arxiv. The key figures of the paper are: 3, 7, 8, and 1
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