Catchment land use effects on fluxes and concentrations of organic and inorganic nitrogen in streams

We present annual downstream fluxes and spatial variation in concentrations of dissolved inorganic nitrogen (NH4+ and NO3−) and dissolved organic nitrogen (DON) in two adjacent Scottish catchments with contrasting land use (agricultural grassland vs. semi-natural moorland). Inter- and intra-catchment variation in N species and the relation to spatial differences in agricultural land use were studied by determining catchment N input through agricultural activities at the field scale and atmospheric inputs at a 25 m grid resolution. The average agricultural N input of 52 kg N ha−1 yr−1 to the grassland catchment was more than 4 times higher than the input of 12 kg N ha−1 yr−1 to the moorland catchment, supplemented by 12.3 and 8.2 kg N ha−1 yr−1 through atmospheric deposition, respectively. The grassland catchment was associated with an annual downstream total dissolved nitrogen (TDN) flux of 14.4 kg N ha−1 yr−1, which was 66% higher than the flux of 8.7 kg ha−1 yr−1 from the moorland catchment. This difference was largely due to the NO3− flux being one order of magnitude higher in the grassland catchment. Dissolved organic N fluxes were similar for the two catchments (7.0 kg ha−1 yr−1) with DON contributing 49% to the TDN flux in the grassland compared with 81% in the moorland catchment. The results highlight the importance of diffuse agricultural N inputs to stream NO3− concentrations and the importance of quantifying all the major aquatic N species for developing a better understanding of N transformations and transport in the atmosphere-soil-water system

Repetitive elements in parasitic protozoa

A recent paper published in BMC Genomics suggests that retrotransposition may be active in the human gut parasite Entamoeba histolytica. This adds to our knowledge of the various types of repetitive elements in parasitic protists and the potential influence of such elements on pathogenicity

Phytochemical Screening and Biological Activities of Combretum adenogonium Leaves Extracts

Combretum adenogonium is beniniens pharmacopoeia medicinal plant used for the treatment of various diseases. This work aims to study the phytochemical and assess some biological activities of C. adenogonium leaves extracts. The phytochemical analysis (qualitative et quantitative) was conducted by standard analytical chemistry method. Antioxydant activity was evaluated by the DPPH method. Antibacterial activity was evaluated in vitro with 10 references strains , 10 Staphylococcus strains isolated from European Scientific Journal October 2017 edition Vol.13, No.30 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 359 meat products and 10 clinical Staphylococcus aureus strains isolated from Buruli ulcer lesions and pus. The Minimum Inhibitory Concentration (MIC) and Bactericidal (CMB) were determined by macrodilution method. The extracts cytotoxic effect was evaluated with Artemia salina larvae. The phytochemical screening revealed the presence of flavonoids, tannins, anthocyanins, saponin and triterpenoids. The methanolique extract present the higest content (450.66 ± 0.004 µg EAG/mg) of total polyphenolic compound. The results showed the good antioxidant activity. The inhibitory diameter zone vary (p < 0.001) according to the strains. The largest medium inhibitory diameter (21.85 ± 0.17 mm) was obtained with the ethanolic extract, while the lowest (6.00 ±0.00 mm) were recorded with water-ethanol extract. The variation between CMI and CMB is not significant (p > 0.05). The higher LD50 (27.66 mg/ml) was recorded with methanol extract. The results of this study confirm some use of C. Adenogonium extracts. But; these extracts must be use with moderatio

Genetic determinants of co-accessible chromatin regions in activated T cells across humans.

Over 90% of genetic variants associated with complex human traits map to non-coding regions, but little is understood about how they modulate gene regulation in health and disease. One possible mechanism is that genetic variants affect the activity of one or more cis-regulatory elements leading to gene expression variation in specific cell types. To identify such cases, we analyzed ATAC-seq and RNA-seq profiles from stimulated primary CD4+ T cells in up to 105 healthy donors. We found that regions of accessible chromatin (ATAC-peaks) are co-accessible at kilobase and megabase resolution, consistent with the three-dimensional chromatin organization measured by in situ Hi-C in T cells. Fifteen percent of genetic variants located within ATAC-peaks affected the accessibility of the corresponding peak (local-ATAC-QTLs). Local-ATAC-QTLs have the largest effects on co-accessible peaks, are associated with gene expression and are enriched for autoimmune disease variants. Our results provide insights into how natural genetic variants modulate cis-regulatory elements, in isolation or in concert, to influence gene expression

AirSWOT measurements of river water surface elevation and slope:Tanana River, AK

Fluctuations in water surface elevation (WSE) along rivers have important implications for water resources, flood hazards, and biogeochemical cycling. However, current in situ and remote sensing methods exhibit key limitations in characterizing spatiotemporal hydraulics of many of the world's river systems. Here we analyze new measurements of river WSE and slope from AirSWOT, an airborne analogue to the Surface Water and Ocean Topography (SWOT) mission aimed at addressing limitations in current remotely sensed observations of surface water. To evaluate its capabilities, we compare AirSWOT WSEs and slopes to in situ measurements along the Tanana River, Alaska. Root-mean-square error is 9.0cm for WSEs averaged over 1km(2) areas and 1.0cm/km for slopes along 10km reaches. Results indicate that AirSWOT can accurately reproduce the spatial variations in slope critical for characterizing reach-scale hydraulics. AirSWOT's high-precision measurements are valuable for hydrologic analysis, flood modeling studies, and for validating future SWOT measurements

Analysis of X chromosome inactivation in autism spectrum disorders.

International audienceAutism spectrum disorders (ASD) are complex genetic disorders more frequently observed in males. Skewed X chromosome inactivation (XCI) is observed in heterozygous females carrying gene mutations involved in several X-linked syndromes. In this study, we aimed to estimate the role of X-linked genes in ASD susceptibility by ascertaining the XCI pattern in a sample of 543 informative mothers of children with ASD and in a sample of 163 affected girls. The XCI pattern was also determined in two control groups (144 adult females and 40 young females) with a similar age distribution to the mothers sample and affected girls sample, respectively. We observed no significant excess of skewed XCI in families with ASD. Interestingly, two mothers and one girl carrying known mutations in X-linked genes (NLGN3, ATRX, MECP2) showed highly skewed XCI, suggesting that ascertainment of XCI could reveal families with X-linked mutations. Linkage analysis was carried out in the subgroup of multiplex families with skewed XCI (> or = 80:20) and a modest increased allele sharing was obtained in the Xq27-Xq28 region, with a peak Z-score of 1.75 close to rs719489. In summary, our results suggest that there is no major X-linked gene subject to XCI and expressed in blood cells conferring susceptibility to ASD. However, the possibility that rare mutations in X-linked genes could contribute to ASD cannot be excluded. We propose that the XCI profile could be a useful criteria to prioritize families for mutation screening of X-linked candidate genes

An investigation of ribosomal protein L10 gene in autism spectrum disorders

<p>Abstract</p> <p>Background</p> <p>Autism spectrum disorders (ASD) are severe neurodevelopmental disorders with the male:female ratio of 4:1, implying the contribution of X chromosome genetic factors to the susceptibility of ASD. The ribosomal protein L10 (RPL10) gene, located on chromosome Xq28, codes for a key protein in assembling large ribosomal subunit and protein synthesis. Two non-synonymous mutations of <it>RPL10</it>, L206M and H213Q, were identified in four boys with ASD. Moreover, functional studies of mutant RPL10 in yeast exhibited aberrant ribosomal profiles. These results provided a novel aspect of disease mechanisms for autism – aberrant processes of ribosome biosynthesis and translation. To confirm these initial findings, we re-sequenced <it>RPL10 </it>exons and quantified mRNA transcript level of <it>RPL10 </it>in our samples.</p> <p>Methods</p> <p>141 individuals with ASD were recruited in this study. All <it>RPL10 </it>exons and flanking junctions were sequenced. Furthermore, mRNA transcript level of <it>RPL10 </it>was quantified in B lymphoblastoid cell lines (BLCL) of 48 patients and 27 controls using the method of SYBR Green quantitative PCR. Two sets of primer pairs were used to quantify the mRNA expression level of <it>RPL10</it>: RPL10-A and RPL10-B.</p> <p>Results</p> <p>No non-synonymous mutations were detected in our cohort. Male controls showed similar transcript level of RPL10 compared with female controls (RPL10-A, U = 81, P = 0.7; RPL10-B, U = 61.5, P = 0.2). We did not observe any significant difference in RPL10 transcript levels between cases and controls (RPL10-A, U = 531, P = 0.2; RPL10-B, U = 607.5, P = 0.7).</p> <p>Conclusion</p> <p>Our results suggest that RPL10 has no major effect on the susceptibility to ASD.</p

Maternal Influences on the Transmission of Leukocyte Gene Expression Profiles in Population Samples from Brisbane, Australia

Two gene expression profiling studies designed to identify maternal influences on development of the neonate immune system and to address the population structure of the leukocyte transcriptome were carried out in Brisbane, Australia. In the first study, a comparison of 19 leukocyte samples obtained from mothers in the last three weeks of pregnancy with 37 umbilical cord blood samples documented differential expression of 7,382 probes at a false discovery rate of 1%, representing approximately half of the expressed transcriptome. An even larger component of the variation involving 8,432 probes, notably enriched for Vitamin E and methotrexate-responsive genes, distinguished two sets of individuals, with perfect transmission of the two profile types between each of 16 mother-child pairs in the study. A minor profile of variation was found to distinguish the gene expression profiles of obese mothers and children of gestational diabetic mothers from those of children born to obese mothers. The second study was of adult leukocyte profiles from a cross-section of Red Cross blood donors sampled throughout Brisbane. The first two axes in this study are related to the third and fourth axes of variation in the first study and also reflect variation in the abundance of CD4 and CD8 transcripts. One of the profiles associated with the third axis is largely excluded from samples from the central portion of the city. Despite enrichment of insulin signaling and aspects of central metabolism among the differentially expressed genes, there was little correlation between leukocyte expression profiles and body mass index overall. Our data is consistent with the notion that maternal health and cytokine milieu directly impact gene expression in fetal tissues, but that there is likely to be a complex interplay between cultural, genetic, and other environmental factors in the programming of gene expression in leukocytes of newborn children