29 research outputs found
Effects of salinity and wet–dry treatments on C and N dynamics in coastal-forested wetland soils: Implications of sea level rise
Forested wetlands dominated by baldcypress (Taxodium distichum) and water tupelo (Nyssa aquatica) are commonly found in coastal regions of the southeastern United States. Global climate change and in particular sea level rise will alter the frequency and magnitude of wet/dry periods and salinity levels in these ecosystems. Soil microcosm experiments were set up to identify the effects of water level variations (0.4–3.0 g-water g-soil−1) and salinity changes (0, 1 and 5 ppt of NaCl) on greenhouse gas emissions (CH4, CO2, and N2O) and dissolved organic carbon (DOC) characteristics from forested wetland soils. Our results indicate that, the effect of water level was much greater than salt intrusion on C and N cycling. Wet–dry treatments significantly decreased DOC production and total CH4-C loss, aromatic and humic-like substance compounds in DOC were increased in both flooding and wet–dry treatments after 60-d incubation. The molecular weight (MW) of DOC, as indicated by E2/E3 ratio and spectral slope, after flooding treatments was higher than that in wet–dry treatments. A first order kinetic model showed there was a positive linear correlation (r2 = 0.73) between CO2 emission rate and DOC concentration which indicated that CO2was mainly generated from DOC. An exponential kinetic model was applied to describe the correlation between CH4 emission rate and DOC concentration (r2 = 0.41). This study demonstrates that an increase in salinity, and in particular variations in wet–dry cycles, will lead to changes in the formation of climate-relevant greenhouse gases, such as CH4, CO2, and N2O
Geochemistry and mineralogy of Western Australian salt lake sediments: Implications for Meridiani Planum on Mars
Hypersaline lakes are characteristic for Western Australia and display a rare combination of geochemical and mineralogical properties which make these lakes potential analogues for past conditions on Mars. In our study we focused on the geochemistry and mineralogy of Lake Orr and Lake Whurr. While both lakes are poor in organic carbon (<1%) the sediments’ pH values differ and range from 3.8 to 4.8 in Lake Orr and from 5.4 to 6.3 in Lake Whurr sediments. Lake Whurr sediments were dominated by orange and red sediment zones in which the main Fe minerals were identified as hematite, goethite, and tentatively jarosite and pyrite. Lake Orr was dominated by brownish and blackish sediments where the main Fe minerals were goethite and another paramagnetic Fe(III)-phase that could not be identified. Furthermore, a likely secondary Fe(II)-phase was observed in Lake Orr sediments. The mineralogy of these two salt lakes in the sampling area is strongly influenced by events such as flooding, evaporation and desiccation, processes that explain at least to some extent the observed differences between Lake Orr and Lake Whurr. The iron mineralogy of Lake Whurr sediments and the high salinity make this lake a suitable analogue for Meridiani Planum on Mars and in particular the tentative identification of pyrite in Lake Whurr sediments has implications for the interpretation of the Fe mineralogy of Meridiani Planum sediments
Telomerase-pulsed dendritic cells: preclinical results and outcome of a clinical phase I/II trial in patients with metastatic renal cell carcinoma
Objective: Therapeutic vaccination with dendritic cells (DC) showed promising results in first clinical trials in cases of metastatic renal cell carcinoma (RCC). Human telomerase reverse transcriptase (hTERT) could be a potential target because it is detectable in more than 85% of human tumors including RCC
MicroRNAs in Renal Cell Carcinoma: Diagnostic Implications of Serum miR-1233 Levels
BACKGROUND: MicroRNA expression is altered in cancer cells, and microRNAs could serve as diagnostic/prognostic biomarker for cancer patients. Our study was designed to analyze circulating serum microRNAs in patients with renal cell carcinoma (RCC). METHODOLOGY/PRINCIPAL FINDINGS: We first explored microrna expression profiles in tissue and serum using taqman low density arrays in each six malignant and benign samples: Although 109 microRNAs were circulating at higher levels in cancer patients' serum, we identified only 36 microRNAs with up-regulation in RCC tissue and serum of RCC patients. Seven candidate microRNAs were selected for verification based on the finding of up-regulation in serum and tissue of RCC patients: miR-7-1*, miR-93, miR-106b*, miR-210, miR-320b, miR-1233 and miR-1290 levels in serum of healthy controls (n = 30) and RCC (n = 33) patients were determined using quantitative real-time PCR (TaqMan MicroRNA Assays). miR-1233 was increased in RCC patients, and thus validated in a multicentre cohort of 84 RCC patients and 93 healthy controls using quantitative real-time PCR (sensitivity 77.4%, specificity 37.6%, AUC 0.588). We also studied 13 samples of patients with angiomyolipoma or oncocytoma, whose serum miR-1233 levels were similar to RCC patients. Circulating microRNAs were not correlated with clinical-pathological parameters. CONCLUSIONS/SIGNIFICANCE: MicroRNA levels are distinctly increased in cancer patients, although only a small subset of circulating microRNAs has a tumor-specific origin. We identify circulating miR-1233 as a potential biomarker for RCC patients. Larger-scaled studies are warranted to fully explore the role of circulating microRNAs in RCC
Difficulties in Determining Prophylactic Transfusion Thresholds of Platelets in Leukemia Patients
A potential role of karyopherin a2 in the impaired maturation of dendritic cells observed in glioblastoma patients
Aim: Patients with glioblastomas demonstrate well-documented immunological impairments including decreased numbers of mature dendritic cells (DCs). Recent data identified karyopherin a2 (KPNA2), a nucleocytoplasmic shuttling receptor, as diagnostic and prognostic biomarker for gliomas. The aim of this ongoing study is to correlate parameters of immunity and nucleocytoplasmic transport in glioblastoma patients.Methods: We preoperatively collected serum from 17 patients with glioblastomas and determined DC subsets (HLA DR+ Lin-, CD34-, CD45+, CD123+, CD11+ were analyzed) using a 6-color flow cytometry panel. Expression levels of KPNA2 and nuclear accumulation of p53 were evaluated semi-quantitatively by immunohistochemistry. O6-methylguanine DNA methyltransferase (MGMT) and isocitrate dehydrogenase-1 (IDH-1) status were assessed by pyrosequencing and immunohistochemistry, respectively.Results: Median expression levels for both KPNA2 and p53 were 5-10%. IDH-1-R132H mutation and MGMT promoter hypermethylation was detected in 3/16 and 1/9 patients, respectively. Mean counts of total mature DCs, myeloid DCs and plasmacytoid DCs were 9.6, 2.1, 3.4 cells/μL. A preliminary analysis suggests an association between low KPNA2 nuclear expression and increased numbers of mature DCs. However, this correlation did not reach statistical significance so far (P = 0.077).Conclusion: Our preliminary data may indicate a role of KPNA2 in the impaired maturation of DCs observed in glioblastoma patients
Western Star, 1903-04-22
The Western Star began publication on Newfoundland's west coast on 4 April 1900, appearing weekly with brief semiweekly periods up to 1952, when it became a daily. As of 17 April 2019 it continues as a free weekly community paper
Organohalide respiration in a pristine hypersaline lake
Despite compiling evidence on distribution of organohalide-respiring bacteria (OHRB) in pristine environments, there is lack of knowledge about their occurrence and potential contribution to the chlorine cycle in extreme environments such as hypersaline lakes. Biotic formation of organohalides (OHs) such as chloromethane and chloroform was recently reported from the hypersaline Lake Strawbridge, Australia. Assuming that natural availability of OHs can prime development of organohalide respiration potential, we prepared microcosms from Lake Strawbridge sediments. Amended chloroform and tetrachloroethene (PCE) were stoichiometrically dechlorinated to dichloromethane and trichloroethene, respectively. MiSeq 16S ribosomal RNA gene analysis and quantitative PCR did not detect any known chloroform and PCE-dechlorinating OHRB in anaerobic sediment microcosms and transfers, which indicated the presence of novel OHRB in hypersaline Lake Strawbridge. To our knowledge, this is the first report on OHR occurrence in extreme pristine environments. Combined with the formerly documented biotic chlorination, this suggests interdependencies between microbial chlorinators and dechlorinators in the local chlorine cycle in an extreme ecosystem
Metagenomic survey of chloroform fate in hypersaline lake Strawbridge in western Australia
Chloroform (CF) is an environmental contaminant that can be naturally formed in hypersaline lake Strawbridge in western Australia. Anaerobic enrichment cultures using sediments from this lake showed CF degradation to dichloromethane (DCM) and CO2. The potential microbes and genes involved in CF degradation were investigated using metagenome sequencing. Known organohalide-respiring bacteria and their reductive dehalogenase genes were not detected. Rather, acetogens like Clostridium and methanogens like Methanosarcina that are capable for co-metabolically degrading CF to DCM and CO2 were detected in the sediment microcosms and enrichment cultures. Additionally, haloalkane dehalogenase and oxygenase that are possibly involved in further aerobic degradation of DCM were also detected in the sediment microcosms and enrichment cultures. These findings show that microbiota may act as a filter for CF emission from hypersaline lakes to the atmosphere