1,194 research outputs found
Structure of C-meso-2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene monohydrate
The resilience of Taiwan's health system to address the COVID-19 pandemic.
10.1016/j.eclinm.2020.100437EClinicalMedicine2410043
Dissimilar effects of human and elephant disturbance on woodland structure and functional bird diversity in the mopane woodlands of Zambia
Context
Humans and elephants are major disturbance agents in the African savanna woodlands. While both species remove trees, humans selectively harvest larger stems, which are less vulnerable to elephants. Increasing human pressures raise the question of how the altered disturbance regime will modify woodland structure, and in turn biodiversity and ecosystem function.
Objectives
Here we investigate this process in the mopane woodlands of Zambia by examining relationships between woodland structure, species and functional bird diversity, and human and elephant disturbance intensity.
Methods
We conducted a single-season comparison of 178 plots from 45 sites using Bayesian mixed models.
Results
The effect of elephants on tree density (− 7.7 ± 1.6%; deviation from intercept) and bird species richness (− 15 ± 6%) was greater than that of humans (density: − 3.5 ± 1.5%; bird richness: − 11.6 ± 4.7%). Despite this, elephants did not significantly affect woody biomass or functional bird diversity, whereas humans had a negative effect on both (woody biomass: − 9.3 ± 2.3%; functional bird diversity: − 5 ± 2%). Elephants were associated with reductions in species and functional turnover (5.3 ± 2.5% and 6 ± 3%, respectively).
Conclusions
Replacement of elephants by humans is likely to reduce woody biomass and functional bird diversity affecting the woodland structure, sustainability, and functioning. Concentrated elephant disturbance could lead to spatial homogeneity in bird species and functional compositions, potentially reducing the spatial resilience of bird communities. This is the first study to highlight how the difference between elephant and human disturbances leads to dissimilar effects on biodiversity
Validated SNPs for eGFR and their associations with albuminuria
Albuminuria and reduced glomerular filtration rate are manifestations of chronic kidney disease (CKD) that predict end-stage renal disease, acute kidney injury, cardiovascular disease and death. We hypothesized that SNPs identified in association with the estimated glomerular filtration rate (eGFR) would also be associated with albuminuria. Within the CKDGen Consortium cohort (n= 31 580, European ancestry), we tested 16 eGFR-associated SNPs for association with the urinary albumin-to-creatinine ratio (UACR) and albuminuria [UACR >25 mg/g (women); 17 mg/g (men)]. In parallel, within the CARe Renal Consortium (n= 5569, African ancestry), we tested seven eGFR-associated SNPs for association with the UACR. We used a Bonferroni-corrected P-value of 0.003 (0.05/16) in CKDGen and 0.007 (0.05/7) in CARe. We also assessed whether the 16 eGFR SNPs were associated with the UACR in aggregate using a beta-weighted genotype score. In the CKDGen Consortium, the minor A allele of rs17319721 in the SHROOM3 gene, known to be associated with a lower eGFR, was associated with lower ln(UACR) levels (beta = −0.034, P-value = 0.0002). No additional eGFR-associated SNPs met the Bonferroni-corrected P-value threshold of 0.003 for either UACR or albuminuria. In the CARe Renal Consortium, there were no associations between SNPs and UACR with a P< 0.007. Although we found the genotype score to be associated with albuminuria (P= 0.0006), this result was driven almost entirely by the known SHROOM3 variant, rs17319721. Removal of rs17319721 resulted in a P-value 0.03, indicating a weak residual aggregate signal. No alleles, previously demonstrated to be associated with a lower eGFR, were associated with the UACR or albuminuria, suggesting that there may be distinct genetic components for these trait
An advanced analytical assessment of rare earth element concentration, distribution, speciation, crystallography and solid-state chemistry in fly ash
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record Data availability: The raw (unprocessed) data that support the findings of this study are available from Mendeley Data: https://data.mendeley.com/datasets/k54hnzxp3j/1.Fly ash represents a promising alternative source of rare earth elements (REE). However, information on REE containing mineral phases and their association with other fly ash components, vital for REE recovery from fly ash, is currently lacking. Herein, the mass fraction, distribution, crystallography and solid-state chemistry of REE, U and Th in Nigerian simulated fly ash samples were characterised using a range of laboratory and synchrotron x-ray based analytical techniques to underpin future extraction methodologies. Inductively coupled plasma mass spectrometry following full-acid digest of forty-five samples revealed recoverable average total REE content which ranged between 442 mgkg−1and 625 mgkg−1, comprising over 30 wt% of the critical REE Nd, Eu, Tb, Dy, Y and Er. These REE within the fly ash samples were found to be most frequently associated with discrete monazite, xenotime and Y-bearing zircon mineral particles, with the former the most detected, which could be beneficiated through gravity separation. Analysis of monazite particles isolated from the composite samples through a complimentary suite of analytical synchrotron radiation techniques revealed a core-shell pattern, with the shell rich in colocalised Ce, Nd and La, and the core enrich in both U and Th. Ce in monazite was found to exist in a mixed trivalent and tetravalent oxidation state, with the monazite structure amorphized due to the high temperature combustion process. Such results demonstrate the strong co-association and physical distribution of REE, U and Th within monazite in fly ash; knowledge of which can subsequently be used to optimise or develop a more selective, cost-effective and environmentally friendly solvent extraction methodology, by targeting the strongly colocalised and surface bound REE in fly ash monazite particles.Engineering and Physical Sciences Research Counci
Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source
Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a wellcharacterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 mu m diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 angstrom ngstrom were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here.11Ysciescopu
Evidence-based gene models for structural and functional annotations of the oil palm genome
The advent of rapid and inexpensive DNA sequencing has led to an explosion of
data waiting to be transformed into knowledge about genome organization and
function. Gene prediction is customarily the starting point for genome
analysis. This paper presents a bioinformatics study of the oil palm genome,
including comparative genomics analysis, database and tools development, and
mining of biological data for genes of interest. We have annotated 26,059 oil
palm genes integrated from two independent gene-prediction pipelines, Fgenesh++
and Seqping. This integrated annotation constitutes a significant improvement
in comparison to the preliminary annotation published in 2013. We conducted a
comprehensive analysis of intronless, resistance and fatty acid biosynthesis
genes, and demonstrated that the high quality of the current genome annotation.
3,658 intronless genes were identified in the oil palm genome, an important
resource for evolutionary study. Further analysis of the oil palm genes
revealed 210 candidate resistance genes involved in pathogen defense. Fatty
acids have diverse applications ranging from food to industrial feedstocks, and
we identified 42 key genes involved in fatty acid biosynthesis in oil palm.
These results provide an important resource for studies of plant genomes and a
theoretical foundation for marker-assisted breeding of oil palm and related
crops
Anaerobic Carbon Monoxide Dehydrogenase Diversity in the Homoacetogenic Hindgut Microbial Communities of Lower Termites and the Wood Roach
Anaerobic carbon monoxide dehydrogenase (CODH) is a key enzyme in the Wood-Ljungdahl (acetyl-CoA) pathway for acetogenesis performed by homoacetogenic bacteria. Acetate generated by gut bacteria via the acetyl-CoA pathway provides considerable nutrition to wood-feeding dictyopteran insects making CODH important to the obligate mutualism occurring between termites and their hindgut microbiota. To investigate CODH diversity in insect gut communities, we developed the first degenerate primers designed to amplify cooS genes, which encode the catalytic (β) subunit of anaerobic CODH enzyme complexes. These primers target over 68 million combinations of potential forward and reverse cooS primer-binding sequences. We used the primers to identify cooS genes in bacterial isolates from the hindgut of a phylogenetically lower termite and to sample cooS diversity present in a variety of insect hindgut microbial communities including those of three phylogenetically-lower termites, Zootermopsis nevadensis, Reticulitermes hesperus, and Incisitermes minor, a wood-feeding cockroach, Cryptocercus punctulatus, and an omnivorous cockroach, Periplaneta americana. In total, we sequenced and analyzed 151 different cooS genes. These genes encode proteins that group within one of three highly divergent CODH phylogenetic clades. Each insect gut community contained CODH variants from all three of these clades. The patterns of CODH diversity in these communities likely reflect differences in enzyme or physiological function, and suggest that a diversity of microbial species participate in homoacetogenesis in these communities
Family- and population-based designs identify different rare causal variants
Both family- and population-based samples are used to identify genetic variants associated with phenotypes. Each strategy has demonstrated advantages, but their ability to identify rare variants and genes containing rare variants is unclear. To compare these two study designs in the identification of rare causal variants, we applied various methods to the population- and family-based data simulated by the Genetic Analysis Workshop 17 with knowledge of the simulated model. Our results suggest that different variants can be identified by different study designs. Family-based and population-based study designs can be complementary in the identification of rare causal variants and should be considered in future studies
A multiscale virtual element method for the analysis of heterogeneous media
We introduce a novel heterogeneous multiscale method for the elastic analysis of two-dimensional domains with a complex microstructure. To this end, the multiscale finite element method is revisited and originally upgraded by introducing virtual element discretizations at the microscale, hence allowing for generalized polygonal and nonconvex elements. The microscale is upscaled through the numerical evaluation of a set of multiscale basis functions. The solution of the equilibrium equations is performed at the coarse scale at a reduced computational cost. We discuss the computation of the multiscale basis functions and corresponding virtual projection operators. The performance of the method in terms of accuracy and computational efficiency is evaluated through a set of numerical examples
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