Model tests on subsurface cavities below road pavement due to sand eruption from the liquefied ground

A significant number of subsurface cavities was found in the liquefied ground after the 2011 Great East Japan earthquake. Using the results of the radar exploration conducted along the coastal area of Tokyo Bay, characteristics of subsurface cavities were investigated. The size and shape of the cavities are larger and thinner compared to those of cavities observed in the non-liquefied ground. A series of model tests was conducted in order to understand the mechanism of sand eruption and underground cavity formation when liquefaction occurs. It was found that the flow rate at the opening seems to be the most important factor for the sand eruption

Atividade microbiana e enzimática em um latossolo ácido sob doses de resíduo de reciclagem de papel.

A reciclagem de papel gera resíduos denominados lodo de Estação de Tratamento de Efluentes (ETE). Sua utilização na agricultura como corretivo de acidez do solo reduz a disposição em aterros sanitários, além de diminuir os custos de produção com calagem. O objetivo foi avaliar o efeito de diferentes doses de reciclagem de papel sobre os atributos microbiológicos de um Latossolo Ácido. O delineamento experimental foi o de blocos completos casualizados com parcelas subdivididas (com aplicação em 2004 e reaplicação em 2008). Foram conduzidos sete tratamentos constituídos de 7 doses de resíduo de reciclagem de papel: 0; 63,6; 127; 191; 254; 382; 510 t/ha e um tratamento com 10,7 t/ha de calcário dolomítico, em três repetições. O delineamento experimental foi o de blocos completos casualizados com parcelas subdivididas (com aplicação em 2004 e reaplicação em 2008). A reaplicação superficial foi de 30 t/ha do mesmo resíduo. A atividade da fosfatase ácida diminuiu com o aumento das doses de resíduo, enquanto a respiração basal aumentou. A biomassa microbiana de carbono e nitrogênio, a atividade da celulase e da desidrogenase não foram influenciadas pelos tratamentos. O principal fator que levou à alteração da atividade da fosfatase ácida e da respiração basal foi o pH do solo.Fertbio

Investigation into the multiple recent sinkholes in Pokhara, Nepal

Since November 2013, numerous sinkholes have been forming in the Armala area of Pokhara Valley, Central Nepal, posing serious threat to local residents. In order to provide countermeasures for reducing sinkhole risk, detailed investigations into the cause and the formation mechanism of the sinkholes are crucial. Preliminary surveys were conducted in June 2014 and November 2014. Comparison of photos, taken in the two surveys, clearly indicates not only the formation of new sinkholes, but also the re-activation of filled sinkholes. By means of dynamic cone penetration tests and surface wave investigations, qualitative characterization of the soil profile was attained, and shallow weak soil layers which are believed to be the location for future sinkholes could be identified. On the basis of the preliminary field investigation, possible sinkhole formation mechanisms are considered. A risk of sinkhole does not seem to disappear as white turbid water continuously springs. It indicates that the internal erosion of white clayey silt layer is still in progress. In August 2015, a boring was carried out beside one of the largest sinkholes. The overall structure of ground layers was first revealed and a 2.5m high cavity at 7.5-10m deep from the ground surface was found within a thick white clayey silt layer. Further ground investigations including surface wave exploration were conducted in December 2015 and the results are reported

High throughput mutagenesis for identification of residues regulating human prostacyclin (hIP) receptor

The human prostacyclin receptor (hIP receptor) is a seven-transmembrane G protein-coupled receptor (GPCR) that plays a critical role in vascular smooth muscle relaxation and platelet aggregation. hIP receptor dysfunction has been implicated in numerous cardiovascular abnormalities, including myocardial infarction, hypertension, thrombosis and atherosclerosis. Genomic sequencing has discovered several genetic variations in the PTGIR gene coding for hIP receptor, however, its structure-function relationship has not been sufficiently explored. Here we set out to investigate the applicability of high throughput random mutagenesis to study the structure-function relationship of hIP receptor. While chemical mutagenesis was not suitable to generate a mutagenesis library with sufficient coverage, our data demonstrate error-prone PCR (epPCR) mediated mutagenesis as a valuable method for the unbiased screening of residues regulating hIP receptor function and expression. Here we describe the generation and functional characterization of an epPCR derived mutagenesis library compromising >4000 mutants of the hIP receptor. We introduce next generation sequencing as a useful tool to validate the quality of mutagenesis libraries by providing information about the coverage, mutation rate and mutational bias. We identified 18 mutants of the hIP receptor that were expressed at the cell surface, but demonstrated impaired receptor function. A total of 38 non-synonymous mutations were identified within the coding region of the hIP receptor, mapping to 36 distinct residues, including several mutations previously reported to affect the signaling of the hIP receptor. Thus, our data demonstrates epPCR mediated random mutagenesis as a valuable and practical method to study the structurefunction relationship of GPCRs. © 2014 Bill et al