358 research outputs found
Hyper-Rayleigh scattering measurements of hyperpolarizabilities for tetrahedral molecules
First hyperpolarizabilities beta of carbon tetrachloride, carbon tetrafluoride, deuterated methane, and methane have been measured by hyper-Rayleigh scattering in gas and liquid phases. The gas-phase results for the coefficient beta xyz (atomic units) are 11.0 +/- 0.9 (CC14), 5.4 +/- 0.4 (CF4), 7.0 +/- 0.6 (CD4), 7.1 +/- 0.7 (CH4). Ab initio calculations are consistent with the measured values for CCl4 and CF4. A discrepancy between theory and experiment remains for CH 4, and is likely due to higher-order vibrational effects not accounted for in calculations. While the effective, liquid-phase beta for CCl 4 is 200% higher than in the gas phase due to collective scattering modes, the liquid environment has little effect on beta for the other molecules. CD4 and CH4 liquids exhibit free-rotor behavior. Liquid-gas comparisons for CF4, CD4, and CH4 show evidence that the Lorentz local-field corrections are inadequate in nonlinear optics. Through z-scan measurements, thermal lensing and/or absorption coefficients have been obtained for six molecules
Measuring the activity of European and African Countries using Social Accounting Matrices
Economic models at the micro, meso and macro levels presuppose the existence of consistent
databases that make it possible to quantify the activity of enterprises, sectors, regions, countries or
continents. Such models can also be important aids in the policy decision process, since they permit
the construction of scenarios resulting from the adoption of policy measures and the consequent
changes that they introduce.
When consistent with the United Nations System of National Accounts (SNA), the Social
Accounting Matrix (SAM) can include all the nominal flows of the measured part of the economy,
at the level of both production and the institutions, and therefore satisfies these requirements. Thus,
in its numerical version, a SAM constitutes a database and provides a snapshot of the measured
reality at a certain moment, whereas its possible algebraic versions, i.e. models that are based upon
it, permit the construction of the above-mentioned scenarios.
The possibility and usefulness of constructing SAMs for African countries consistent with the SNA
will be examined and experimented. The SAM’s basic structure and consistency within the whole
system will be studied, as well as any possible disaggregations, extensions, aggregates, indicators
and balances that can be calculated. Other aspects beyond that basic structure will also be examined
in order to show to what extent the SAM is capable of covering parts of the economy that are not
covered by the SNA.info:eu-repo/semantics/publishedVersio
Invertebrates of ancient heavy metal spoil and smelting tip sites in southern Jordan: Thier distribution and use as bioindicators of metalliferous pollution derived from ancient sources
Critical conditions for the wetting of soils
The wettability of soil is of great importance for plants and soil biota and in determining whether flooding and soil erosion will occur. The analysis used in common measurements of soil hydrophobicity makes the assumption that water always enters soils if the average contact angle between the soil and water is 90 degrees or lower; these tests have been used for decades. The authors show theoretically and experimentally that water cannot enter many soils unless the contact angle is considerably lower than this, down to approximately 50 degrees. This difference generates serious errors in determining and modeling soil wetting behavior
King Solomon's Miners- Starvation and Bioaccumulation? An Environmental Archaeological Investigation in Southern Jordan
Radon and King Solomons Miners: Faynan Orefeild, Jordanian desert
Concentrations of 222Rn were measured in ancient copper mines which exploited the Faynan Orefield in the South-Western Jordanian Desert. The concentrations of radon gas detected indicate that the ancient metal workers would have been exposed to a significant health risk and indicate that any future attempt to exploit the copper ores must deal with the hazard identified. Seasonal variations in radon concentrations are noted and these are linked to the ventilation of the mines. These modern data are used to explore the differential exposure to radon and the health of ancient mining communities
Importancia de la biotecnologia vegetal en la uva apirena
Palladium catalysed coupling reactions of 6-O-tert-butyldimethylsilyl-1-bromocodeine and 6-O-tert-butyldimethylsilyl-3-trifluoromethylsulfonylmorphine allow a range of substituted analogues of codeine in the 1-position and morphine in the 3-position to be efficiently and selectively prepared
Microsatellite instability analysis in hereditary non-polyposis colon cancer using the Bethesda consensus panel of microsatellite markers in the absence of proband normal tissue
BACKGROUND: Hereditary non-polyposis colon cancer (HNPCC) is an autosomal dominant syndrome predisposing to the early development of various cancers including those of colon, rectum, endometrium, ovarium, small bowel, stomach and urinary tract. HNPCC is caused by germline mutations in the DNA mismatch repair genes, mostly hMSH2 or hMLH1. In this study, we report the analysis for genetic counseling of three first-degree relatives (the mother and two sisters) of a male who died of colorectal adenocarcinoma at the age of 23. The family fulfilled strict Amsterdam-I criteria (AC-I) with the presence of extracolonic tumors in the extended pedigree. We overcame the difficulty of having a proband post-mortem non-tumor tissue sample for MSI testing by studying the alleles carried by his progenitors. METHODS: Tumor MSI testing is described as initial screening in both primary and metastasis tumor tissue blocks, using the reference panel of 5 microsatellite markers standardized by the National Cancer Institute (NCI) for the screening of HNPCC (BAT-25, BAT-26, D2S123, D5S346 and D17S250). Subsequent mutation analysis of the hMLH1 and hMSH2 genes was performed. RESULTS: Three of five microsatellite markers (BAT-25, BAT-26 and D5S346) presented different alleles in the proband's tumor as compared to those inherited from his parents. The tumor was classified as high frequency microsatellite instability (MSI-H). We identified in the HNPCC family a novel germline missense (c.1864C>A) mutation in exon 12 of hMSH2 gene, leading to a proline 622 to threonine (p.Pro622Thr) amino acid substitution. CONCLUSION: This approach allowed us to establish the tumor MSI status using the NCI recommended panel in the absence of proband's non-tumor tissue and before sequencing the obligate carrier. According to the Human Gene Mutation Database (HGMD) and the International Society for Gastrointestinal Hereditary Tumors (InSiGHT) Database this is the first report of this mutation
Development of B Cells and Erythrocytes Is Specifically Impaired by the Drug Celastrol in Mice
Background: Celastrol, an active compound extracted from the root of the Chinese medicine ‘‘Thunder of God Vine’’ (Tripterygium wilfordii), exhibits anticancer, antioxidant and anti-inflammatory activities, and interest in the therapeutic potential of celastrol is increasing. However, described side effects following treatment are significant and require investigation prior to initiating clinical trials. Here, we investigated the effects of celastrol on the adult murine hematopoietic system. Methodology/Principal Findings: Animals were treated daily with celastrol over a four-day period and peripheral blood, bone marrow, spleen, and peritoneal cavity were harvested for cell phenotyping. Treated mice showed specific impairment of the development of B cells and erythrocytes in all tested organs. In bone marrow, these alterations were accompanied by decreases in populations of common lymphoid progenitors (CLP), common myeloid progenitors (CMP) and megakaryocyte-erythrocyte progenitors (MEP). Conclusions/Significance: These results indicate that celastrol acts through regulators of adult hematopoiesis and could be used as a modulator of the hematopoietic system. These observations provide valuable information for further assessmen
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