scholarly journals Temporal and Spatial Coexistence of Archaeal and BacterialamoAGenes and Gene Transcripts in Lake Lucerne

Archaea ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Elisabeth W. Vissers ◽  
Flavio S. Anselmetti ◽  
Paul L. E. Bodelier ◽  
Gerard Muyzer ◽  
Christa Schleper ◽  
...  

Despite their crucial role in the nitrogen cycle, freshwater ecosystems are relatively rarely studied for active ammonia oxidizers (AO). This study of Lake Lucerne determined the abundance of bothamoAgenes and gene transcripts of ammonia-oxidizing archaea (AOA) and bacteria (AOB) over a period of 16 months, shedding more light on the role of both AO in a deep, alpine lake environment. At the surface, at 42 m water depth, and in the water layer immediately above the sediment, AOA generally outnumbered AOB. However, in the surface water during summer stratification, when both AO were low in abundance, AOB were more numerous than AOA. Temporal distribution patterns of AOA and AOB were comparable. Higher abundances ofamoAgene transcripts were observed at the onset and end of summer stratification. In summer, archaealamoAgenes and transcripts correlated negatively with temperature and conductivity. Concentrations of ammonium and oxygen did not vary enough to explain theamoAgene and transcript dynamics. The observed herbivorous zooplankton may have caused a hidden flux of mineralized ammonium and a change in abundance of genes and transcripts. At the surface, AO might have been repressed during summer stratification due to nutrient limitation caused by active phytoplankton.

2005 ◽  
Vol 16 (2) ◽  
pp. 291-304 ◽  
Author(s):  
Kazuo Aoyama

To provide some insights into the nature and role of warfare in the rise, development, and decline of Classic Maya civilization, this article discusses spear, dart, and arrow points used by the Classic Maya elites at the rapidly abandoned fortified city of Aguateca, Guatemala, and their temporal and spatial distribution patterns in and around Copan, Honduras. Both the royal family and elite scribes/artists at Aguateca used spear and dart points for intergroup human conflict as well as for artistic and craft production under enemy threat. An important implication is that the ruler and elite scribes/artists were also warriors. The unusually high concentrations of identifiable weaponry at the Early Classic hilltop center of Cerro de las Mesas as well as the Acropolis and other Late Classic locations in the Copan Valley, along with other lines of evidence, indicate that warfare was critical in the development and downfall of Classic Maya civilization at Copan.


2010 ◽  
Vol 27 (1-2) ◽  
pp. 81-90
Author(s):  
Krishna Poudel

Mountains have distinct geography and are dynamic in nature compared to the plains. 'Verticality' and 'variation' are two fundamental specificities of the mountain geography. They possess distinct temporal and spatial characteristics in a unique socio-cultural setting. There is an ever increasing need for spatial and temporal data for planning and management activities; and Geo Information (GI) Science (including Geographic Information and Earth Observation Systems). This is being recognized more and more as a common platform for integrating spatial data with social, economic and environmental data and information from different sources. This paper investigates the applicability and challenges of GISscience in the context of mountain geography with ample evidences and observations from the mountain specific publications, empirical research findings and reports. The contextual explanation of mountain geography, mountain specific problems, scientific concerns about the mountain geography, advances in GIScience, the role of GIScience for sustainable development, challenges on application of GIScience in the contexts of mountains are the points of discussion. Finally, conclusion has been made with some specific action oriented recommendations.


Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 57
Author(s):  
Konstantinos Vantas ◽  
Epaminondas Sidiropoulos

The identification and recognition of temporal rainfall patterns is important and useful not only for climatological studies, but mainly for supporting rainfall–runoff modeling and water resources management. Clustering techniques applied to rainfall data provide meaningful ways for producing concise and inclusive pattern classifications. In this paper, a timeseries of rainfall data coming from the Greek National Bank of Hydrological and Meteorological Information are delineated to independent rainstorms and subjected to cluster analysis, in order to identify and extract representative patterns. The computational process is a custom-developed, domain-specific algorithm that produces temporal rainfall patterns using common characteristics from the data via fuzzy clustering in which (a) every storm may belong to more than one cluster, allowing for some equivocation in the data, (b) the number of the clusters is not assumed known a priori but is determined solely from the data and, finally, (c) intra-storm and seasonal temporal distribution patterns are produced. Traditional classification methods include prior empirical knowledge, while the proposed method is fully unsupervised, not presupposing any external elements and giving results superior to the former.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 156
Author(s):  
Mohammad Al Hasan ◽  
Patricia E. Martin ◽  
Xinhua Shu ◽  
Steven Patterson ◽  
Chris Bartholomew

GPR56 is required for the adipogenesis of preadipocytes, and the role of one of its ligands, type III collagen (ColIII), was investigated here. ColIII expression was examined by reverse transcription quantitative polymerase chain reaction, immunoblotting and immunostaining, and its function investigated by knockdown and genome editing in 3T3-L1 cells. Adipogenesis was assessed by oil red O staining of neutral cell lipids and production of established marker and regulator proteins. siRNA-mediated knockdown significantly reduced Col3a1 transcripts, ColIII protein and lipid accumulation in 3T3-L1 differentiating cells. Col3a1−/− 3T3-L1 genome-edited cell lines abolished adipogenesis, demonstrated by a dramatic reduction in adipogenic moderators: Pparγ2 (88%) and C/ebpα (96%) as well as markers aP2 (93%) and oil red O staining (80%). Col3a1−/− 3T3-L1 cells displayed reduced cell adhesion, sustained active β-catenin and deregulation of fibronectin (Fn) and collagen (Col4a1, Col6a1) extracellular matrix gene transcripts. Col3a1−/− 3T3-L1 cells also had dramatically reduced actin stress fibres. We conclude that ColIII is required for 3T3-L1 preadipocyte adipogenesis as well as the formation of actin stress fibres. The phenotype of Col3a1−/− 3T3-L1 cells is very similar to that of Gpr56−/− 3T3-L1 cells, suggesting a functional relationship between ColIII and Gpr56 in preadipocytes.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Monica del C. Gomez-Alonso ◽  
Anja Kretschmer ◽  
Rory Wilson ◽  
Liliane Pfeiffer ◽  
Ville Karhunen ◽  
...  

Abstract Background The discovery of robust and trans-ethnically replicated DNA methylation markers of metabolic phenotypes, has hinted at a potential role of epigenetic mechanisms in lipid metabolism. However, DNA methylation and the lipid compositions and lipid concentrations of lipoprotein sizes have been scarcely studied. Here, we present an epigenome-wide association study (EWAS) (N = 5414 total) of mostly lipid-related metabolic measures, including a fine profiling of lipoproteins. As lipoproteins are the main players in the different stages of lipid metabolism, examination of epigenetic markers of detailed lipoprotein features might improve the diagnosis, prognosis, and treatment of metabolic disturbances. Results We conducted an EWAS of leukocyte DNA methylation and 226 metabolic measurements determined by nuclear magnetic resonance spectroscopy in the population-based KORA F4 study (N = 1662) and replicated the results in the LOLIPOP, NFBC1966, and YFS cohorts (N = 3752). Follow-up analyses in the discovery cohort included investigations into gene transcripts, metabolic-measure ratios for pathway analysis, and disease endpoints. We identified 161 associations (p value < 4.7 × 10−10), covering 16 CpG sites at 11 loci and 57 metabolic measures. Identified metabolic measures were primarily medium and small lipoproteins, and fatty acids. For apolipoprotein B-containing lipoproteins, the associations mainly involved triglyceride composition and concentrations of cholesterol esters, triglycerides, free cholesterol, and phospholipids. All associations for HDL lipoproteins involved triglyceride measures only. Associated metabolic measure ratios, proxies of enzymatic activity, highlight amino acid, glucose, and lipid pathways as being potentially epigenetically implicated. Five CpG sites in four genes were associated with differential expression of transcripts in blood or adipose tissue. CpG sites in ABCG1 and PHGDH showed associations with metabolic measures, gene transcription, and metabolic measure ratios and were additionally linked to obesity or previous myocardial infarction, extending previously reported observations. Conclusion Our study provides evidence of a link between DNA methylation and the lipid compositions and lipid concentrations of different lipoprotein size subclasses, thus offering in-depth insights into well-known associations of DNA methylation with total serum lipids. The results support detailed profiling of lipid metabolism to improve the molecular understanding of dyslipidemia and related disease mechanisms.


2020 ◽  
Vol 8 (3) ◽  
pp. 216 ◽  
Author(s):  
Cristiana Guerranti ◽  
Guido Perra ◽  
Tania Martellini ◽  
Luisa Giari ◽  
Alessandra Cincinelli

Plastic debris occurring in freshwater environments, which can either come from the surrounding terrestrial areas or transported from upstream, has been identified as one of the main sources and routes of plastic pollution in marine systems. The ocean is the final destination of land- based microplastic sources, but compared to marine environments, the occurrence and effects of microplastics in freshwater ecosystems remain largely unknown. A thorough examination of scientific literature on abundance, distribution patterns, and characteristics of microplastics in freshwater environments in Mediterranean tributary rivers has shown a substantial lack of information and the need to apply adequate and uniform measurement methods.


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