Synthesis of Visible-Light Driven CrxOy-TiO2 Binary Photocatalyst System Based on Hierarchical Macro-Mesoporous Silica

Hierarchical macro–mesoporous silica materials co-incorporated with Cr and Ti were directly synthesized by adopting close-packed array of polystyrene microsphere as hard template for macropore through a simple soaking-calcination way, where Si/Ti ratio was fixed at 200 and Si/Cr ratio was set between 200 and 10. Ti specie is highly dispersed in porous matrix and Cr specie mainly exists as tetra-coordinated CrO3 at higher Si/Cr ratio (Si/Cr ≥ 50), which transforms to a mixture of CrO3 and crystallized hexa-coordinated Cr2O3when Si/Cr ratio is below 50. This highly interconnected porous material co-incorporated with Cr and Ti presents highest visible-light driven photocatalytic activity at Si/Cr = 20 toward degradation of AO7. Moreover, macro–mesoporous photocatalyst presents higher activity than those of macroporous and mesoporous ones at the same Si/Cr ratio. The improved visible light driven catalytic activity is mainly attributed to effective metal to metal charge transfer from Cr(VI) to Ti(IV) benefitted from the uniform dispersion of these two species in hierarchical porous silica matrix

Making Free Trade Fair

Philosophers have done very little work on what makes trade fair. Perhaps the most extensive discussion is Malgorzata Kurjanska and Mathias Risse’s article, “Fairness in Trade II: export subsidies and the fair trade movement.”2 In their article, Kurjanska and Risse consider the case for trade subsidies and the Fair Trade movement. They suggest that it is not permissible for developed countries to give their producers subsidies because doing so does not strike an appropriate balance between meeting the needs of the global poor and protecting domestic workers (Kurjanska and Risse, 2008: 34). Kurjanska and Risse also argue that the case for Fair Trade hinges, primarily, on whether or not it is part of the best development strategy for poor countries. They do not think Fair Trade is part of the best development strategy and, so, they believe purchasing Fair Trade certified goods is only acceptable because doing so does not constitute a large share of the market in traded goods. This chapter argues that the case against subsidies and Fair Trade Kurjanska and Risse present is much weaker than they make out. To the contrary, it argues that giving some subsidies and purchasing some Fair Trade certified goods may even be necessary to make trade fair. Section 11.2 starts by saying a few words about the normative framework Kurjanska and Risse adopt

Regulation of the DNA Damage Response and Gene Expression by the Dot1L Histone Methyltransferase and the 53Bp1 Tumour Suppressor

Dot1L, a histone methyltransferase that targets histone H3 lysine 79 (H3K79), has been implicated in gene regulation and the DNA damage response although its functions in these processes remain poorly defined.Using the chicken DT40 model system, we generated cells in which the Dot1L gene is disrupted to examine the function and focal recruitment of the 53Bp1 DNA damage response protein. Detailed kinetic and dose response assays demonstrate that, despite the absence of H3K79 methylation demonstrated by mass spectrometry, 53Bp1 focal recruitment is not compromised in these cells. We also describe, for the first time, the phenotypes of a cell line lacking both Dot1L and 53Bp1. Dot1L⁻/⁻ and wild type cells are equally resistant to ionising radiation, whereas 53Bp1⁻/⁻/Dot1L⁻/⁻ cells display a striking DNA damage resistance phenotype. Dot1L and 53Bp1 also affect the expression of many genes. Loss of Dot1L activity dramatically alters the mRNA levels of over 1200 genes involved in diverse biological functions. These results, combined with the previously reported list of differentially expressed genes in mouse ES cells knocked down for Dot1L, demonstrates surprising cell type and species conservation of Dot1L-dependent gene expression. In 53Bp1⁻/⁻ cells, over 300 genes, many with functions in immune responses and apoptosis, were differentially expressed. To date, this is the first global analysis of gene expression in a 53Bp1-deficient cell line.Taken together, our results uncover a negative role for Dot1L and H3K79 methylation in the DNA damage response in the absence of 53Bp1. They also enlighten the roles of Dot1L and 53Bp1 in gene expression and the control of DNA double-strand repair pathways in the context of chromatin

Proteomic Interrogation of Human Chromatin

Chromatin proteins provide a scaffold for DNA packaging and a basis for epigenetic regulation and genomic maintenance. Despite understanding its functional roles, mapping the chromatin proteome (i.e. the “Chromatome”) is still a continuing process. Here, we assess the biological specificity and proteomic extent of three distinct chromatin preparations by identifying proteins in selected chromatin-enriched fractions using mass spectrometry-based proteomics. These experiments allowed us to produce a chromatin catalog, including several proteins ranging from highly abundant histone proteins to less abundant members of different chromatin machinery complexes. Using a Normalized Spectral Abundance Factor approach, we quantified relative abundances of the proteins across the chromatin enriched fractions giving a glimpse into their chromosomal abundance. The large-scale data sets also allowed for the discovery of a variety of novel post-translational modifications on the identified chromatin proteins. With these comparisons, we find one of the probed methods to be qualitatively superior in specificity for chromatin proteins, but inferior in proteomic extent, evidencing a compromise that must be made between biological specificity and broadness of characterization. Additionally, we attempt to identify proteins in eu- and heterochromatin, verifying the enrichments by characterizing the post-translational modifications detected on histone proteins from these chromatin regions. In summary, our results provide insights into the value of different methods to extract chromatin-associated proteins and provide starting points to study the factors that may be involved in directing gene expression and other chromatin-related processes

Modelling alpine permafrost distribution based on energy-balance data: a first step

The computer model PERMEBAL (which stands for Permafrost and Energy Balance) simulates the persistence of snow cover and daily ground surface temperatures of snow-free gridpoints. It was developed for high-mountain conditions. The model describes different vertical energy fluxes at the surface. With meteorological and site-specific input data, PERMEBAL delivers daily ground surface temperatures of snow-free gridpoints. Special emphasis is given to simulation of snow-cover development (snow fall, snow redistribution, snowmelt). The resulting ground surface temperature data are intended for use as input data for future ground heat flux simulations. The aim is to model ground thermal conditions and thus permafrost distribution. The model was applied to the Corvatsch-Furtschellas area (16 km², Engadin, eastern Switzerland). The results show that the area could be divided into three classes of mean annual sums of daily ground surface temperatures of snow-free pixels, similar to ‘permafrost probable’, ‘permafrost possible’ and ‘permafrost improbable’ classifications used in earlier empirical permafrost distribution models

Assessment of lactic acid bacteria sensitivity to terpenoids with the Biolog methodology

International audienceTerpenoids are plant metabolites which can be found in traces in the milk of animals fed with fresh forages. To these compounds, many biological properties, including antimicrobial activity, have been recognized. However, no information about the sensitivity of lactic acid bacteria (naturally occurring in milk and dairy products) to terpenoids are currently available. The Biolog methodology, which is traditionally used for the metabolic characterization of microorganisms, has also been found suitable for the evaluation of the activity exerted by plant components against bacterial consortia, allowing to establish the duration of antimicrobial activity (if present) and its resulting effect on microorganisms viability. In the present work, this approach was employed to study the effect of six oxygenated terpenoids (geraniol, linalool, alpha-terpineol, terpinen-4-ol, carvone, and menthone), which can be found in dairy products, towards 27 lactic acid bacterial strains (thermophilic or mesophilic, homo- or hetero-fermenting cocci), previously isolated from raw goat milk. Results showed that microorganisms were variously affected by the selected molecules. In some cases, terpenoids seemed to have a stimulating action; while in others, a transient antimicrobial activity was highlighted, without evident relationship with the metabolic/physiologic groups to which the tested bacterial strains belonged