4,195 research outputs found
Transcriptional signatures of wheat inforescence development
In order to maintain global food security, it will be necessary to increase yields of the cereal crops that provide most of the calories and protein for the world’s population, which includes common wheat (Triticum aestivum L.). An important wheat yield component is the number of grain-holding spikelets which form on the spike during inflorescence development. Characterizing the gene regulatory networks controlling the timing and rate of inflorescence development will facilitate the selection of natural and induced gene variants that contribute to increased spikelet number and yield. In the current study, co-expression and gene regulatory networks were assembled from a temporal wheat spike transcriptome dataset, revealing the dynamic expression profiles associated with the progression from vegetative meristem to terminal spikelet formation. Consensus co-expression networks revealed enrichment of several transcription factor families at specific developmental stages including the sequential activation of different classes of MIKC-MADS box genes. This gene regulatory network highlighted interactions among a small number of regulatory hub genes active during terminal spikelet formation. Finally, the CLAVATA and WUSCHEL gene families were investigated, revealing potential roles for TtCLE13, TtWOX2, and TtWOX7 in wheat meristem development. The hypotheses generated from these datasets and networks further our understanding of wheat inflorescence development.
IntroductionFil: VanGessel, Carl. Colorado State University; Department of Soil and Crop Sciences; Estados UnidosFil: Hamilton, James. Colorado State University; Department of Soil and Crop Sciences; Estados UnidosFil: Tabbita, Facundo. Universidad de Córdoba. Escuela Técnica Superior de Ingeniería Agronómica y de Montes. Departamento de Genética; España. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Dubcovsky, Jorge. University of California, Department of Plant Sciences; Estados Unidos. Howard Hughes Medical Institute; Estados UnidosFil: Pearce, Stephen. Rothamsted Research. Sustainable Soils and Crops; Reino Unido. Colorado State University; Department of Soil and Crop Sciences; Estados Unido
Transcriptional signatures of wheat inflorescence development
In order to maintain global food security, it will be necessary to increase yields of the cereal crops that provide most of the calories and protein for the world’s population, which includes common wheat (Triticum aestivum L.). An important wheat yield component is the number of grain-holding spikelets which form on the spike during inflorescence development. Characterizing the gene regulatory networks controlling the timing and rate of inflorescence development will facilitate the selection of natural and induced gene variants that contribute to increased spikelet number and yield. In the current study, co-expression and gene regulatory networks were assembled from a temporal wheat spike transcriptome dataset, revealing the dynamic expression profiles associated with the progression from vegetative meristem to terminal spikelet formation. Consensus co-expression networks revealed enrichment of several transcription factor families at specific developmental stages including the sequential activation of different classes of MIKC-MADS box genes. This gene regulatory network highlighted interactions among a small number of regulatory hub genes active during terminal spikelet formation. Finally, the CLAVATA and WUSCHEL gene families were investigated, revealing potential roles for TtCLE13, TtWOX2, and TtWOX7 in wheat meristem development. The hypotheses generated from these datasets and networks further our understanding of wheat inflorescence developme
Understanding the PSCz Galaxy Power Spectrum with N-body Simulations
By comparing the PSCz galaxy power spectrum with the results of nested pure
dark matter N-body simulations, we try to understand how infrared-selected
galaxies populate dark-matter haloes, paying special attention to the method of
halo identification in the simulations. We thus test the hypothesis that
baryonic physics negligibly affects the distribution of galaxies down to the
smallest scales yet observed. We are successful in reproducing the PSCz power
spectrum on scales < ~40 h/Mpc, near our resolution limit, by imposing a
central density cut-off on simulated haloes, which gives a rough minimum mass
and circular velocity of haloes in which PSCz galaxies formed.Comment: 12 pages, 16 figures (one added), conforms to version in MNRA
Niche expansion and temperature sensitivity of tropical African montane forests
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Abstract
Aim Climate and land-use change will have a dramatic impact on future ecosystems through alterations to species ranges and community composition. When forming conservation strategies, correlative species distribution models are often created to assess risks for individual species. These models are based on the assumption of climatic equilibrium, such that the modern range is representative of the full range of conditions under which species could thrive. However, the palaeo-ecological record illustrates examples of disequilibrium in species today, and recent studies suggest that many species could occur in much broader climatic settings than previously thought. Montane ecosystems are thought to be at disproportionate risk due to temperature sensitivity and restricted geographical ranges. However, in the Afrotropics the palaeo-ecological record shows that montane forest taxa expanded into the lowlands numerous times, suggesting a possible tolerance to warm temperatures.
Location Africa.
Methods We integrate palaeo-ecological and palaeo-climatic data in order to compare climate conditions in which species are currently found with those in the past. We use species distribution models to construct potential modern ranges for Afromontane species based on modern distributions and distributions in the palaeo-ecological record in order to evaluate the equilibrium of species ranges.
Results We show that many Afromontane trees have occupied warmer climates in the past, which suggests that the current low-elevation boundaries are not set by climate. Interestingly, the species with the largest disequilibrium between palaeo- and modern distributions are those whose modern distributions show the least temperature sensitivity. Mapping of species potential ranges based on modern and palaeo- distributions clearly shows that suitable climate conditions exist today in the lowlands for less temperature-sensitive species.
Main conclusions These results imply that the current range of these forest trees does not necessarily inform risk from climatic change, and that human land use may be the major pressure for many species in the future.Thanks to Maria Orbay-Cerrato for pollen processing in the lab and funding from the Voss Postdoctoral Fellowship Program at Brown University. We would also like to thank two anonymous referees for their kind comments and insights. This research was funded by the ERA-Net BiodivERsA, with the national funders Portugal, Germany, Sweden and France, part of the 2012 BiodivERsA call for research proposals
Prevalence and risk factors for chronic kidney disease of unknown cause in Malawi: a cross-sectional analysis in a rural and urban population
Background: An epidemic of chronic kidney disease of unknown cause (CKDu) is occurring in rural communities in tropical regions of low-and middle-income countries in South America and India. Little information is available from Southern African countries which have similar climatic and occupational characteristics to CKDu-endemic countries. We investigated whether CKDu is prevalent in Malawi and identified its potential risk factors in this setting. /
Methods: We conducted a cross-sectional study from January–August 2018 collecting bio samples and anthropometric data in two Malawian populations. The sample comprised adults > 18 years (n = 821) without diabetes, hypertension, and proteinuria. Estimates of glomerular filtration rate (eGFR) were calculated using the CKD-EPI equation. Linear and logistic regression models were applied with potential risk factors, to estimate risk of reduced eGFR. /
Results: The mean eGFR was 117.1 ± 16.0 ml/min per 1.73m2 and the mean participant age was 33.5 ± 12.7 years. The prevalence of eGFR< 60 was 0.2% (95% confidence interval (95% CI) 0.1, 0.9); the prevalence of eGFR< 90 was 5% (95% CI =3.2, 6.3). We observed a higher prevalence in the rural population (5% (3.6, 7.8)), versus urban (3% (1.4, 6.7)). Age and BMI were associated with reduced eGFR< 90 [Odds ratio (OR) (95%CI) =3.59 (2.58, 5.21) per ten-year increment]; [OR (95%CI) =2.01 (1.27, 3.43) per 5 kg/m2 increment] respectively. No increased risk of eGFR < 90 was observed for rural participants [OR (95%CI) =1.75 (0.50, 6.30)]. /
Conclusions: Reduced kidney function consistent with the definition of CKDu is not common in the areas of Malawi sampled, compared to that observed in other tropical or sub-tropical countries in Central America and South Asia. Reduced eGFR< 90 was related to age, BMI, and was more common in rural areas. These findings are important as they contradict some current hypothesis that CKDu is endemic across tropical and sub-tropical countries. This study has enabled standardized comparisons of impaired kidney function between and within tropical/subtropical regions of the world and will help form the basis for further etiological research, surveillance strategies, and the implementation and evaluation of interventions
Prevalence and risk factors for chronic kidney disease of unknown cause in Malawi: a cross-sectional analysis in a rural and urban population.
BACKGROUND: An epidemic of chronic kidney disease of unknown cause (CKDu) is occurring in rural communities in tropical regions of low-and middle-income countries in South America and India. Little information is available from Southern African countries which have similar climatic and occupational characteristics to CKDu-endemic countries. We investigated whether CKDu is prevalent in Malawi and identified its potential risk factors in this setting. METHODS: We conducted a cross-sectional study from January-August 2018 collecting bio samples and anthropometric data in two Malawian populations. The sample comprised adults > 18 years (n = 821) without diabetes, hypertension, and proteinuria. Estimates of glomerular filtration rate (eGFR) were calculated using the CKD-EPI equation. Linear and logistic regression models were applied with potential risk factors, to estimate risk of reduced eGFR. RESULTS: The mean eGFR was 117.1 ± 16.0 ml/min per 1.73m2 and the mean participant age was 33.5 ± 12.7 years. The prevalence of eGFR< 60 was 0.2% (95% confidence interval (95% CI) 0.1, 0.9); the prevalence of eGFR< 90 was 5% (95% CI =3.2, 6.3). We observed a higher prevalence in the rural population (5% (3.6, 7.8)), versus urban (3% (1.4, 6.7)). Age and BMI were associated with reduced eGFR< 90 [Odds ratio (OR) (95%CI) =3.59 (2.58, 5.21) per ten-year increment]; [OR (95%CI) =2.01 (1.27, 3.43) per 5 kg/m2 increment] respectively. No increased risk of eGFR < 90 was observed for rural participants [OR (95%CI) =1.75 (0.50, 6.30)]. CONCLUSIONS: Reduced kidney function consistent with the definition of CKDu is not common in the areas of Malawi sampled, compared to that observed in other tropical or sub-tropical countries in Central America and South Asia. Reduced eGFR< 90 was related to age, BMI, and was more common in rural areas. These findings are important as they contradict some current hypothesis that CKDu is endemic across tropical and sub-tropical countries. This study has enabled standardized comparisons of impaired kidney function between and within tropical/subtropical regions of the world and will help form the basis for further etiological research, surveillance strategies, and the implementation and evaluation of interventions
Macro economy, stock market and oil prices: Do meaningful relationships exist among their cyclical fluctuations?
This paper examines the relationship among consumer price index, industrial production, stock market and oil prices in Greece. Initially we use a unified statistical framework (cointegration and VECM) to study the data in levels. We then employ a multivariate VAR model to examine the relationship between the cyclical components of our series. The period of the study is from 1996:1 – 2008:6. Findings suggest that oil prices and the stock market exercise a positive effect on the Greek CPI, in the long run. Cyclical components analysis suggests that oil prices exercise significant negative influence to the stock market. In addition, oil prices are negatively influencing CPI, at a significant level. However, we find no effect of oil prices on industrial production and CPI. Finally, no relationship can be documented between the industrial production and stock market for the Greek market. The findings of this study are of a particular interest and importance to policy makers, financial managers, financial analysts and investors dealing with the Greek economy and the Greek stock market
Simulating the Formation of the Local Galaxy Population
We simulate the formation and evolution of the local galaxy population
starting from initial conditions with a smoothed linear density field which
matches that derived from the IRAS 1.2 Jy galaxy survey. Our simulations track
the formation and evolution of all dark matter haloes more massive than 10e+11
solar masses out to a distance of 8000 km/s from the Milky Way. We implement
prescriptions similar to those of Kauffmann et al. (1999) to follow the
assembly and evolution of the galaxies within these haloes. We focus on two
variants of the CDM cosmology: an LCDM and a tCDM model. Galaxy formation in
each is adjusted to reproduce the I-band Tully-Fisher relation of Giovanelli et
al. (1997). We compare the present-day luminosity functions, colours,
morphology and spatial distribution of our simulated galaxies with those of the
real local population, in particular with the Updated Zwicky Catalog, with the
IRAS PSCz redshift survey, and with individual local clusters such as Coma,
Virgo and Perseus. We also use the simulations to study the clustering bias
between the dark matter and galaxies of differing type. Although some
significant discrepancies remain, our simulations recover the observed
intrinsic properties and the observed spatial distribution of local galaxies
reasonably well. They can thus be used to calibrate methods which use the
observed local galaxy population to estimate the cosmic density parameter or to
draw conclusions about the mechanisms of galaxy formation. To facilitate such
work, we publically release our z=0 galaxy catalogues, together with the
underlying mass distribution.Comment: 25 pages, 20 figures, submitted to MNRAS. High resolution copies of
figures 1 and 3, halo and galaxy catalogues can be found at
http://www.mpa-garching.mpg.de/NumCos/CR/index.htm
"Treading in sand": A qualitative study of the impact of austerity on inequalities in mental health
Successive UK governments since 2010 have adopted policies of austerity characterized by public spending and social security cuts. There has been little qualitative research exploring the effects of these policies on inequalities in mental health. This article presents findings from a case study of Stockton‐on‐Tees, a local authority in the North East of England with exceptionally high spatial and socio‐economic inequalities. Qualitative interviews were undertaken with people experiencing mental health problems in different areas of the local authority, alongside interviews with key stakeholders. The findings offer an insight into spatial inequalities in people's lives, and the impact of deprivation on mental health. They suggest that austerity measures are having a damaging impact on individuals and communities in the most deprived areas of this unequal place, whilst leaving those from less deprived areas relatively unscathed—with the exception of increased job insecurity. The cuts in social security are impacting on health through both material and psychosocial pathways including increased financial hardship and chronic stress. The intrusion of the state into people's everyday lives was such that the notion of the “home as an asylum” was broken, giving many no respite from the draining day‐to‐day experiences of poverty. The findings are discussed in relation to the continuing program of welfare changes and public spending cuts in the United Kingdom, including avenues for further research and key recommendations for policymaker
Spatial clustering in the ESO-Sculptor Survey: two-point correlation functions by galaxy type at redshifts 0.1 - 0.5
We calculate the spatial two-point auto and cross-correlation functions for
the 765 galaxies with Rc<21.5 and 0.1<z<0.51 in the ESO-Sculptor survey, and
explore the segregation effects among the populations of giant (early-type,
late spiral) and dwarf (dE, dI) galaxies. At separation of 0.3 h^-1 Mpc, pairs
of early-type galaxies dominate the clustering over all the other types of
pairs. At intermediate scales, 0.3-5 h^-1 Mpc, mixed pairs of dwarf and giant
galaxies contribute equally as pairs of giant galaxies, whereas the latter
dominate at ~10 h^-1 Mpc. We detect the signature of the transition between the
1-halo and 2-halo regimes which is expected in the scenario of galaxy formation
by hierarchical merging of dark matter halos. The early-type galaxies largely
outdo the late spiral galaxies in their 1-halo component, whereas the 2-halo
components of both giant populations are comparable. The dwarf galaxies have an
intermediate 1-halo component between the 2 giant galaxy types, and their
2-halo component is weak and consistent with null clustering. The present
analysis indicates that the early-type galaxies are preferentially located near
the centers of the most massive halos, whereas late spiral galaxies tend to
occupy their outskirts or the centers of less massive halos. This analysis also
unveils new results on the spatial distribution of dwarf galaxies: at the scale
at which they significantly cluster inside the halos (<0.3 h^-1 Mpc), they are
poorly mixed with the late spiral galaxies, and appear preferentially as
satellites of early-type galaxies.Comment: Astronomy & Astrophysics, in press. 29 pages, 15 color figures, 3
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