G9a mediates Sharp-1–dependent inhibition of skeletal muscle differentiation

10.1091/mbc.E12-04-0311Molecular Biology of the Cell23244778-478

G9a mediates Sharp-1–dependent inhibition of skeletal muscle differentiation

10.1091/mbc.E12-04-0311Molecular Biology of the Cell23244778-478

Editorial

No abstract

G9a, a multipotent regulator of gene expression

10.4161/epi.23331Epigenetics8116-2

Lysine methyltransferase G9a methylates the transcription factor MyoD and regulates skeletal muscle differentiation

10.1073/pnas.1111628109Proceedings of the National Academy of Sciences1093841-84

Assessing Changes and Fragmentations of Forest Cover in the Northern Province, Sri Lanka

Forest cover change and fragmentation have become a global concern and are linked to the decline of the ecosystem's integrity. It also negatively affects biodiversity, forest degradation, and the spatial pattern of the landscape. Human population increase and accompanying activities like agricultural expansion, resettlement, deforestation, and infrastructural development all contribute to forest cover changes and forest fragmentation. Geospatial technologies, such as remote sensing (RS) and geographic information system (GIS), have expanded the potential for investigating, monitoring, analysing, and reporting on important biodiversity changes. This study aims to assess and quantify the extent and pattern of forest cover changes and forest cover fragmentations in the Northern Province since 1990. From 1990 to 2020, multi-temporal satellite images (Landsat: TM, ETM, OLI) and digital image processing were used to assess and spatially describe forest cover changes. Forest fragmentations were measured by number of patches, patch size coefficient of variance (PSCoV), class area, edge density, mean shape index and average weighted mean shape index using Patch Analyst in the ArcGIS environment. The study shows that large amounts of forest cover have decreased over the last 30 years in the Northern Province. The lands for agriculture, homestead, and scrub increased by 9.16%, 13.33%, and 4.4%, respectively during the last 30 years, while forest cover decreased by 24.07%. As a result, the Northern Province’s Forest is more fragmented. The total forest patches increased by 53,536 patches over the 30 years, the mean patch size (MPS) reduced from 21.75 in 1990 to 5.79 in 2020 and PSCoV decreased by roughly 85.95% from 7663.14 ha in 1990 to 1077.03 ha in 2020. Forest cover in Northern Province has not been disturbed much by three decades (1980-2009) of civil war, however, there were significant changes in forest cover after the war due to increasing resettlements in new places, development initiations, indiscriminate forest logging, land grabbing and agricultural expansion. The trend of fast deforestation and increasing forest fragmentation in the Northern Province effects on natural habitats of wildlife, biodiversity and the livelihood activities of the people. In this setting, it is critical to adopt appropriate policies to balance the environment via sustainable land use planning. The findings of this research provide a solid foundation for the necessities of sustainable development planning in Northern Province. Keywords: Remote Sensing and GIS, Satellite images, Forest cover change, Fragmentation, Northern Provinc

Magnetoelectric ordering of BiFeO3 from the perspective of crystal chemistry

In this paper we examine the role of crystal chemistry factors in creating conditions for formation of magnetoelectric ordering in BiFeO3. It is generally accepted that the main reason of the ferroelectric distortion in BiFeO3 is concerned with a stereochemical activity of the Bi lone pair. However, the lone pair is stereochemically active in the paraelectric orthorhombic beta-phase as well. We demonstrate that a crucial role in emerging of phase transitions of the metal-insulator, paraelectric-ferroelectric and magnetic disorder-order types belongs to the change of the degree of the lone pair stereochemical activity - its consecutive increase with the temperature decrease. Using the structural data, we calculated the sign and strength of magnetic couplings in BiFeO3 in the range from 945 C down to 25 C and found the couplings, which undergo the antiferromagnetic-ferromagnetic transition with the temperature decrease and give rise to the antiferromagnetic ordering and its delay in regard to temperature, as compared to the ferroelectric ordering. We discuss the reasons of emerging of the spatially modulated spin structure and its suppression by doping with La3+.Comment: 18 pages, 5 figures, 3 table

Holistically Evaluating Agent Based Social System Models

The philosophical perspectives on model evaluation can be broadly classified into reductionist/logical positivist and relativist/holistic. In this paper, we outline some of our past efforts in, and challenges faced during, evaluating models of social systems with cognitively detailed agents. Owing to richness in the model, we argue that the holistic approach and consequent continuous improvement are essential to evaluating complex social system models such as these. A social system built primarily of cognitively detailed agents can provide multiple levels of correspondence, both at observable and abstract aggregated levels. Such a system can also pose several challenges, including large feature spaces, issues in information elicitation with database, experts and news feeds, counterfactuals, fragmented theoretical base, and limited funding for validation. We subscribe to the view that no model can faithfully represent reality, but detailed, descriptive models are useful in learning about the system and bringing about a qualitative jump in understanding of the system it attempts to model – provided they are properly validated. Our own approach to model evaluation is to consider the entire life cycle and assess the validity under two broad dimensions of (1) internally focused validity/quality achieved through structural, methodological, and ontological evaluations; and (2) external validity consisting of micro validity, macro validity, and qualitative, causal and narrative validity. In this paper, we also elaborate on selected validation techniques that we have employed in the past. We recommend a triangulation of multiple validation techniques, including methodological soundness, qualitative validation techniques, such as face validation by experts and narrative validation, and formal validation tests, including correspondence testing

Reduction Reactions of Electrolyte Salts for Lithium Ion Batteries: LiPF6, LiBF4, LiDFOB, LiBOB, and LiTFSI

The reduction products of common lithium salts for lithium ion battery electrolytes, LiPF6, LiBF4, lithium bisoxalato borate (LiBOB), lithium difluorooxalato borate (LiDFOB), and lithium trifluorosulfonylimide (LiTFSI), have been investigated. The solution phase reduction of different lithium salts via reaction with the one electron reducing agent, lithium naphthalenide, results in near quantitative reactions. Analysis of the solution phase and head space gasses suggests that all of the reduction products are precipitated as insoluble solids. The solids obtained through reduction were analyzed with solution NMR, IR-ATR and XPS. All fluorine containing salts generate LiF upon reduction while all oxalate containing salts generate lithium oxalate. In addition, depending upon the salt other species including, LixPFyOz, LixBFy, oligomeric borates, and lithium bis[N-(trifluoromethylsulfonylimino)] trifluoromethanesulfonate are observed