Study on sliding stability of porous-concrete retaining wall model test subjected to rainfall infiltration

The common disadvantage of a conventional retaining wall is a heavy object as a block that is difficult to lift and handle conveniently. A drainage pipe is commonly used to displace water from the backfill. In areas with high annual rainfall, the soil could be saturated in a short time and added lateral load significantly. In this study, porous concrete was utilized as a retaining wall material with the advantages of the lighter weight of the block and additional drainage capability due to its high void ratio. A set of a laboratory-scale retaining walls using conventional and porous concrete walls was investigated through three different rainfall modes. To initiate the instability condition, a vertical load was applied then the lateral moving was recorded using LVDT sensors. Soil moisture content sensors recorded hydrologic responses of the saturation process. The loading test results showed that the porous concrete wall model was being displaced less than experienced by the conventional concrete wall. It shows that the porous concrete wall model can withstand the load as the additional lateral load from infiltrated rainwater dissipates rapidly. Therefore, the porous concrete wall has the advantage of being used as a Retaining Wall Material.

Can I Afford to Publish? A Dilemma for African Scholars

With open-access publishing authors pay an article processing charge and subsequently their article is freely available online. These charges are beyond the reach of most African academics. Thus, the trend towards open access publishing will shift the business model from a pay-wall model, where access to literature is limited, to a pay-to-publish one, where African scholars cannot afford to publish. We explore the costs of publishing and the ability of African scholars to afford to publish as open access. Three-quarters of the 40 top ecology journals required payment for open-access publishing (average cost $3,150). Paying such fees is a hardship for African scholars as grant funding is not available and it is not feasible to pay the fees themselves as salaries are low. We encourage funders and publishers to facilitate an equitable publishing model that allows African scholars to make their research available through open-access publishing.

A Novel Mouse Wound Model for Scar Tissue Formation in Abdominal-Muscle Wall

Scar tissue formation is a result of excess healing reactions after wounding. Hypertrophic scars scarcely develop in a mouse. In the present study, we established a novel experimental model of a scar-forming wound by resecting a small portion of the abdominal wall on the lower center of the abdomen, which exposed contractive forces by the surrounding muscle tissue. As a tension-less control, a back-skin excision model was used with a splint fixed onto the excised skin edge, and granulation tissue formed on the muscle facia supported by the back skeleton. One week after the resection, initial healing reactions such as fibroblast proliferation took place in both models. However, after 21 days, lesions with collagen-rich granulation tissues forming multiple nodular/spherical-like structures developed only in the abdominal-wall model. The lesions are analogous to scar lesions in humans. Such lesions, however, did not develop in the back-skin excision model. Therefore, this animal model is unique in that fibrous scar tissues form under a physiological condition without using any artificial factors and is valuable for studying the pathogenesis and preclinical treatment of scar lesions.