91 research outputs found
Damaging insect pests and diseases and their threats to agarwood tree plantations
The cultivation of agarwood tree species such as Aquilaria has grown dramatically during the last ten years. This
development is driven by the desire to produce sustainable agarwood to meet the high market demand. In the past, the
main source of agarwood had been from natural forests, which resources are now declining. Although there are various
examples of pests and diseases affecting early plantations, these damages were often overlooked. Recently, the emergence
of new pests and diseases in large-scale Aquilaria tree plantations has raised concerns among planters and researchers,
as the damage level to the trees may vary from unsubstantial to tree mortality. Lack of information on the types of pests
and diseases in Aquilaria plantations makes it difficult to properly manage these threats, leading to economic losses.
This review summarizes the insect pests and diseases known to damage cultivated agarwood trees in various countries
including China, India, Indonesia, and Malaysia. As we learn from the cultivation practices of other monoculture crops,
these insect pests and pathogens are a major challenge to the healthy growth of agarwood trees. The implementation
of an integrated pest and disease management at an early stage of plantation establishment may hold the key to help
control and contain these threats from turning into major outbreaks
Prognostic Value of Leucocyte Telomere Length in Acute Myocardial Infarction
Introduction: Leucocyte telomere length (LTL) has been described as a marker of biological age, endothelial dysfunction and atherosclerosis. The association between LTL and clinical characteristics of Asian patients, and their outcomes following acute myocardial infarction (AMI) have been inconclusive.
Objective: To investigate the relationship between LTL and developing AMI, the association of LTL with inpatient and 30-day mortality, and the comparison to LTL with established AMI risk scores in predicting these outcomes.
Methodology: 100 patients aged 30-70 years admitted with an AMI to a tertiary referral center between May-Oct 2017 were enrolled; these were matched with 100 non-AMI ('healthy') controls for gender and age (+/- 1 year). Clinical data was obtained prospectively; inpatient and 30-day outcomes documented. LTL was reflected by a well described variable called a tis ratio (TSR).
The TSR was measured at enrolment using a quantitative PCR-based methods (qPCR) and results blinded to the clinician
Chitosan Modification and Pharmaceutical/Biomedical Applications
Chitosan has received much attention as a functional biopolymer for diverse applications, especially in pharmaceutics and medicine. Our recent efforts focused on the chemical and biological modification of chitosan in order to increase its solubility in aqueous solutions and absorbability in the in vivo system, thus for a better use of chitosan. This review summarizes chitosan modification and its pharmaceutical/biomedical applications based on our achievements as well as the domestic and overseas developments: (1) enzymatic preparation of low molecular weight chitosans/chitooligosaccharides with their hypocholesterolemic and immuno-modulating effects; (2) the effects of chitin, chitosan and their derivatives on blood hemostasis; and (3) synthesis of a non-toxic ion ligand—D-Glucosaminic acid from Oxidation of D-Glucosamine for cancer and diabetes therapy
Extensive Promoter-Centered Chromatin Interactions Provide a Topological Basis for Transcription Regulation
Higher-order chromosomal organization for transcription
regulation is poorly understood in eukaryotes.
Using genome-wide Chromatin Interaction
Analysis with Paired-End-Tag sequencing (ChIAPET),
we mapped long-range chromatin interactions
associated with RNA polymerase II in human cells
and uncovered widespread promoter-centered intragenic,
extragenic, and intergenic interactions. These
interactions further aggregated into higher-order
clusters, wherein proximal and distal genes were
engaged through promoter-promoter interactions.
Most genes with promoter-promoter interactions
were active and transcribed cooperatively, and
some interacting promoters could influence each
other implying combinatorial complexity of transcriptional
controls. Comparative analyses of
different cell lines showed that cell-specific chromatin
interactions could provide structural frameworks
for cell-specific transcription, and suggested
significant enrichment of enhancer-promoter interactions
for cell-specific functions. Furthermore,
genetically-identified disease-associated noncoding
elements were found to be spatially engaged with
corresponding genes through long-range interactions.
Overall, our study provides insights into transcription
regulation by three-dimensional chromatin
interactions for both housekeeping and cell-specific
genes in human cells
Temporal population variability in local forest communities has mixed effects on tree species richness across a latitudinal gradient
Among the local processes that determine species diversity in ecological communities, fluctuation‐dependent mechanisms that are mediated by temporal variability in the abundances of species populations have received significant attention. Higher temporal variability in the abundances of species populations can increase the strength of temporal niche partitioning but can also increase the risk of species extinctions, such that the net effect on species coexistence is not clear. We quantified this temporal population variability for tree species in 21 large forest plots and found much greater variability for higher latitude plots with fewer tree species. A fitted mechanistic model showed that among the forest plots, the net effect of temporal population variability on tree species coexistence was usually negative, but sometimes positive or negligible. Therefore, our results suggest that temporal variability in the abundances of species populations has no clear negative or positive contribution to the latitudinal gradient in tree species richness
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
Porosity and permeability evaluation of pervious concrete using three-dimensional x-ray computed tomography
The functional performance of pervious concrete pavement surfaces (such as hydraulic, acoustic and frictional performances) is greatly influenced by the design of the pervious concrete mixture and its internal pore structure. With the advancement in computational imaging technologies, it is now possible to adopt X-ray computed tomography techniques to determine the internal pore structures of pervious concrete pavement surfaces. This paper examines the use of medical three-dimensional X-ray computed tomography (CT) to determine the effective porosity and the permeability in pervious concrete pavement surfaces. X-ray CT scans on different pervious concrete pavement specimens are performed and various tomographic reconstruction algorithms are tested to evaluate the performance in estimating effective porosity and permeability in pervious concrete. Our finding is that such techniques are capable of providing a non-destructive interpretation on pervious concrete mix effective porosity and permeability with potential applications in pervious concrete mix design.Papers Presented at the 2018 37th Southern African Transport Conference 9-12 July 2018 Pretoria, South Africa. Theme "Towards a desired transport future: safe, sufficient and affordable"
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