On-Orbit Results of Photoelectron Current Measurement System in Low Earth Orbit on HORYU-IV Satellite

On-orbit photoelectron current experiment is one of the missions carried out with the less resource available from a HORYU-IV satellite, for measuring the current from metallic and insulator surfaces from air mass zero (AMO) spectrum. This is with the view to determined photoelectron potential of materials widely used in spacecraft in space. HORYU-IV also known as Arc Event Generator and Investigator satellite (AEGIS) is among HORYU satellite series of Kyushu Institute of Technology, which was launched on February 17, 2016 as a piggy-back on-board H-IIA rocket. The measurement system consists of current-voltage amplifier circuits for Au, Kapton and Black Kapton samples with varying gains and other discrete components. We present the analysis of the telemetry data obtained after the launch; validate the effectiveness of the design and verification processes. The results show that the current measured from Black kapton sample surface had 1.80 nA and 2.70 nA, corresponds to 69.1ᵒ and 75.1ᵒ minimum and maximum elevation angles respectively. This paper described the on-orbit result of PEC and its verification through ground tests

Pathway-Wide Association Study Implicates Multiple Sterol Transport and Metabolism Genes in HDL Cholesterol Regulation

Pathway-based association methods have been proposed to be an effective approach in identifying disease genes, when single-marker association tests do not have sufficient power. The analysis of quantitative traits may be benefited from these approaches, by sampling from two extreme tails of the distribution. Here we tested a pathway association approach on a small genome-wide association study (GWAS) on 653 subjects with extremely high high-density lipoprotein cholesterol (HDL-C) levels and 784 subjects with low HDL-C levels. We identified 102 genes in the sterol transport and metabolism pathways that collectively associate with HDL-C levels, and replicated these association signals in an independent GWAS. Interestingly, the pathways include 18 genes implicated in previous GWAS on lipid traits, suggesting that genuine HDL-C genes are highly enriched in these pathways. Additionally, multiple biologically relevant loci in the pathways were not detected by previous GWAS, including genes implicated in previous candidate gene association studies (such as LEPR, APOA2, HDLBP, SOAT2), genes that cause Mendelian forms of lipid disorders (such as DHCR24), and genes expressing dyslipidemia phenotypes in knockout mice (such as SOAT1, PON1). Our study suggests that sampling from two extreme tails of a quantitative trait and examining genetic pathways may yield biological insights from smaller samples than are generally required using single-marker analysis in large-scale GWAS. Our results also implicate that functionally related genes work together to regulate complex quantitative traits, and that future large-scale studies may benefit from pathway-association approaches to identify novel pathways regulating HDL-C levels

Regular Multivitamin Supplement Use, Single Nucleotide Polymorphisms in ATIC, SHMT2, and SLC46A1, and Risk of Ovarian Carcinoma

ATIC, SHMT2, and SLC46A1 have essential roles in one-carbon (1-C) transfer. The authors examined whether associations between ovarian carcinoma and 15 variants in these genes are modified by regular multivitamin use, a source of 1-C donors, among Caucasian participants from two US case–control studies. Using a phased study design, variant-by-multivitamin interactions were tested, and associations between variants and ovarian carcinoma were reported stratified by multivitamin supplement use. Per-allele risk associations were modified by multivitamin use at six variants among 655 cases and 920 controls (Phase 1). In a larger sample of 968 cases and 1,265 controls (Phases 1 and 2), interactions were significant (P ≤ 0.03) for two variants, particularly among regular multivitamin users: ATIC rs7586969 [odds ratio (OR) = 0.7, 95% confidence interval (CI) = 0.6–0.9] and ATIC rs16853834 (OR = 1.5, 95% CI = 1.1–2.0). The two ATIC single nucleotide polymorphisms (SNPs) did not share the same haplotype; however, the haplotypes they comprised mirrored their SNP risk associations among regular multivitamin supplement users. A multi-variant analysis was also performed by comparing the observed likelihood ratio test statistic from adjusted models with and without the two ATIC variant-by-multivitamin interaction terms with a null distribution of test statistics generated by permuting case status 10,000 times. The corresponding observed P value of 0.001 was more extreme than the permutation-derived P value of 0.009, suggesting rejection of the null hypothesis of no association. In summary, there is little statistical evidence that the 15 variants are independently associated with risk of ovarian carcinoma. However, the statistical interaction of ATIC variants with regular multivitamin intake, when evaluated at both the SNP and gene level, may support these findings as relevant to ovarian health and disease processes

Variation in Onset of Leaf Unfolding and Wood Formation in a Central African Tropical Tree Species

A diversity of phenological strategies has been reported for tropical tree species. Defoliation and seasonal dormancy of cambial activity inform us on how trees cope with water stress during the dry season, or maximize the use of resources during the rainy season. Here, we study the matching between leaf phenology (unfolding and shedding) and cambial activity for Prioria balsamifera, a key timber species in the Democratic Republic of Congo. In particular, we (i) evaluated the seasonality of cambial activity and synchrony of phenology among trees in response to climate and (ii) identified the seasonality of leaf phenology and its relation with cambial phenology. The study was conducted in the Luki Man and Biosphere Reserve, located in the Mayombe forest at the southern margin of the Congo Basin. Historic defoliation data were collected every ten days using weekly crown observations whereas recent observations involved timelapse cameras. Cambial pinning was performed on ten trees during 20 months and radius dendrometers were installed on three trees during 13 months. Tree rings were measured on cores from 13 trees and growth synchrony was evaluated. We found that P. balsamifera defoliates annually with a peak observed at the end of the dry season and the beginning of the rainy season. The new leaves unfolded shortly after shedding of the old leaves. The peak defoliation dates varied across years from September 12 to November 14 and the fraction of number of trees that defoliated at a given time was found to be negatively correlated with annual rainfall and temperature; during the dry season, when precipitation and temperatures are the lowest. Wood formation (radial growth), was found to be highly seasonal, with cambial dormancy occurring during the dry season and growth starting at the beginning of the rainy season. Individual ringwidth series did not cross date well. The within species variability of leaf phenology and cambial rhythms provides indication about resistance of the population against climatic changes

Overexpression of Patatin-Related Phospholipase AIIIβ Altered the Content and Composition of Sphingolipids in Arabidopsis

In plants, fatty acids are primarily synthesized in plastids and then transported to the endoplasmic reticulum for synthesis of most of the complex membrane lipids, including glycerolipids and sphingolipids. The first step of sphingolipid synthesis, which uses a fatty acid and a serine as substrates, is critical for sphingolipid homeostasis; its disruption leads to an altered plant growth. Phospholipase As (PLAs) have been implicated in the trafficking of fatty acids from plastids to the endoplasmic reticulum. Previously, we found that overexpression of a patatin-related phospholipase, pPLAIIIβ, resulted in a smaller plant size and altered anisotropic cell expansion. Here, we determined the content and composition of sphingolipids in pPLAIIIβ-knockout and overexpression plants (pPLAIIIβ-KO and -OE). 3-keto-sphinganine, the product of the first step of sphingolipid synthesis, had a 26% decrease in leaves of pPLAIIIβ-KO while a 52% increase in pPLAIIIβ-OE compared to wild type (WT). The levels of free long-chain base species, dihydroxy-C18:0 and trihydroxy-18:0 (d18:0 and t18:0), were 38% and 97% higher, respectively, in pPLAIIIβ-OE than in WT. The level of complex sphingolipids ceramide d18:0-16:0 and t18:1-16:0 had a 2-fold increase in pPLAIIIβ-OE. The level of hydroxyceramide d18:0-h16:0 was 72% higher in pPLAIIIβ-OE compared to WT. The levels of several species of glucosylceramide and glycosylinositolphosphoceramide tended to be higher in pPLAIIIβ-OE than in WT. The total content of the complex sphingolipids showed a slightly higher in pPLAIIIβ-OE than in WT. These results revealed an involvement of phospholipase-mediated lipid homeostasis in plant growth

TAL effectors and activation of predicted host targets distinguish Asian from African strains of the rice pathogen Xanthomonas oryzae pv. oryzicola while strict conservation suggests universal importance of five TAL effectors

Xanthomonas oryzae pv. oryzicola (Xoc) causes the increasingly important disease bacterial leaf streak of rice (BLS) in part by type III delivery of repeat-rich transcription activator-like (TAL) effectors to upregulate host susceptibility genes. By pathogen whole genome, single molecule, real-time sequencing and host RNA sequencing, we compared TAL effector content and rice transcriptional responses across 10 geographically diverse Xoc strains. TAL effector content is surprisingly conserved overall, yet distinguishes Asian from African isolates. Five TAL effectors are conserved across all strains. In a prior laboratory assay in rice cv. Nipponbare, only two contributed to virulence in strain BLS256 but the strict conservation indicates all five may be important, in different rice genotypes or in the field. Concatenated and aligned, TAL effector content across strains largely reflects relationships based on housekeeping genes, suggesting predominantly vertical transmission. Rice transcriptional responses did not reflect these relationships, and on average, only 28% of genes upregulated and 22% of genes downregulated by a strain are up- and downregulated (respectively) by all strains. However, when only known TAL effector targets were considered, the relationships resembled those of the TAL effectors. Toward identifying new targets, we used the TAL effector-DNA recognition code to predict effector binding elements in promoters of genes upregulated by each strain, but found that for every strain, all upregulated genes had at least one. Filtering with a classifier we developed previously decreases the number of predicted binding elements across the genome, suggesting that it may reduce false positives among upregulated genes. Applying this filter and eliminating genes for which upregulation did not strictly correlate with presence of the corresponding TAL effector, we generated testable numbers of candidate targets for four of the five strictly conserved TAL effectors

A general framework of persistence strategies for biological systems helps explain domains of life

The nature and cause of the division of organisms in superkingdoms is not fully understood. Assuming that environment shapes physiology, here we construct a novel theoretical framework that helps identify general patterns of organism persistence. This framework is based on Jacob von Uexküll’s organism-centric view of the environment and James G. Miller’s view of organisms as matter-energy-information processing molecular machines. Three concepts describe an organism's environmental niche: scope, umwelt and gap. Scope denotes the entirety of environmental events and conditions to which the organism is exposed during its lifetime. Umwelt encompasses an organism's perception of these events. The gap is the organism's blind spot, the scope that is not covered by umwelt. These concepts bring organisms of different complexity to a common ecological denominator. Ecological and physiological data suggest organisms persist using three strategies: flexibility, robustness and economy. All organisms use umwelt information to flexibly adapt to environmental change. They implement robustness against environmental perturbations within the gap generally through redundancy and reliability of internal constituents. Both flexibility and robustness improve survival. However, they also incur metabolic matter-energy processing costs, which otherwise could have been used for growth and reproduction. Lineages evolve unique tradeoff solutions among strategies in the space of what we call a persistence triangle. Protein domain architecture and other evidence support the preferential use of flexibility and robustness properties. Archaea and Bacteria gravitate toward the triangle’s economy vertex, with Archaea biased toward robustness. Eukarya trade economy for survivability. Protista occupy a saddle manifold separating akaryotes from multicellular organisms. Plants and the more flexible Fungi share an economic stratum, and Metazoa are locked in a positive feedback loop toward flexibility

Respiratory Tract Aspergillosis in the Sputum of Patients Suspected of Tuberculosis in Fako Division-Cameroon

Abstract Respiratory tract aspergillosis refers to fungi infections of the respiratory tract caused by Aspergillus species. Respiratory tract aspergillosis has clinical and radiological characteristics which are very similar to tuberculosis thereby making the disease easily misdiagnosed and mistreated as tuberculosis. This prompted us to investigate the prevalence of respiratory tract Aspergillus sp. in the sputum of patients suspected of pulmonary tuberculosis and to study the anti-fungal susceptibility of the isolated Aspergillus strains. Two hundred sputa samples were studied for Aspergillus sp. and M. tuberculosis. Direct microscopy and fungal culture was done on two sets of Sabouraud Dextrose agar. Analysis for Acid-Fast Bacilli (AFB) was done by the Auramine-phenol fluorochrome technique. Aspergillus sp were isolated from 30(15%) patients; A. fumigatus was isolated in 10 (5%) patients while A. niger, A. flavus, and A. terreus were isolated from 9 (4.5%), 6 (3%) and 5 (2.5%) patients respectively. M. tuberculosis was found in 27(13.5%) and a co-infection of 9(4.5%) was observed.Using the broth micro dilution technique, the minimum inhibitory concentrations (MICs) for Aspergillus sp for nystatin, itraconazole and amphotericin B ranged between 0.12->16 μg/ml, 0.06->16 μg/ml and 0.12-0.5 μg/ml, respectively. All the Aspergillus terreus strains were consistently sensitive to itraconazole (MIC >16 μg/ml)

D1FHS, the type strain of the ammonia-oxidizing bacterium Nitrosococcus wardiae spec. nov.: Enrichment, isolation, phylogenetic and growth physiological characterization

An ammonia-oxidizing bacterium, strain D1FHS, was enriched into pure culture from a sediment sample retrieved in Jiaozhou Bay, a hyper-eutrophic semi-closed water body hosting the metropolitan area of Qingdao, China. Based on initial 16S rRNA gene sequence analysis, strain D1FHS was classified in the genus Nitrosococcus, family Chromatiaceae, order Chromatiales, class Gammaproteobacteria; the 16S rRNA gene sequence with highest level of identity to that of D1FHS was obtained from Nitrosococcus halophilus Nc4T. The average nucleotide identity between the genomes of strain D1FHS and Nitrosococcus halophilus strain Nc4 is 89.5%. Known species in the genus Nitrosococcus are obligate aerobic chemolithotrophic ammonia-oxidizing bacteria adapted to and restricted to marine environments. The optimum growth (maximum nitrite production) conditions for D1FHS in a minimal salts medium are: 50 mM ammonium and 700 mM NaCl at pH of 7.5 to 8.0 and at 37°C in dark. Because pertinent conditions for other studied Nitrosococcus spp. are 100-200 mM ammonium and <700 mM NaCl at pH of 7.5 to 8.0 and at 28-32°C, D1FHS is physiologically distinct from other Nitrosococcus spp. in terms of substrate, salt and thermal tolerance

Membrane vesicle production by Chlamydia trachomatis as an adaptive response

Bacteria have evolved specific adaptive responses to cope with changing environments. These adaptations include stress response phenotypes with dynamic modifications of the bacterial cell envelope and generation of membrane vesicles (MVs). The obligate intracellular bacterium, Chlamydia trachomatis, typically has a biphasic lifestyle, but can enter into an altered growth state typified by morphologically aberrant chlamydial forms, termed persistent growth forms, when induced by stress in vitro. How C. trachomatis can adapt to a persistent growth state in host epithelial cells in vivo is not well understood, but is an important question, since it extends the host-bacterial relationship in vitro and has thus been indicated as a survival mechanism in chronic chlamydial infections. Here, we review recent findings on the mechanistic aspects of bacterial adaptation to stress with a focus on how C. trachomatis remodels its envelope, produces MVs, and the potential important consequences of MV production with respect to host-pathogen interactions. Emerging data suggest that the generation of MVs may be an important mechanism for C. trachomatis intracellular survival of stress, and thus may aid in the establishment of a chronic infection in human genital epithelial cells