Fe-Al binary composite filled dialysis membrane tubes (DMT-HFAO): a modified method for assessment of phosphate desorption from aqueous and soil solutions.

Phosphorus (P) limits plant growth particularly in strongly acidic soils due to P fixation. P availability to a plant is a functional concept of time rather than a measurable quantity. Therefore, a method that can estimate P availability over time is required. This research work was intended to synthesize a nanocomposite material that can monitor soil P desorption kinetics. To this effect, a binary sorbent system filled in a dialysis membrane tube was developed. Accordingly, calcined and amorphous powder samples of Fe-Al binary mixed oxides were synthesized by a gel-evaporation method and characterized by XRD, FTIR, TGA-DTA, SEM-EDX and BET techniques. The performance, as a phosphate sink, of crystalline hydrous ferric aluminum oxide (HFAO) and hydrous amorphous ferric aluminum oxide (HAFAO) each filled in a dialysis membrane tube (DMT) was evaluated. A single hydrated ferric oxide (HFO) suspension filled in dialysis membrane tubes (DMT) designated DMT-HFO was used as a benchmark. For the aqueous system, the sorption capacity of the DMT-HFAO was found to be 260% (mg mg-1 phosphate) whereas the amorphous congener (DMT-HAFAO) was approximately 200% (mg mg-1 phosphate) times that of DMT-HFO during the 24 h equilibration. For the soil solution system, the phosphate desorbed by the DMT-HFAO was about 520% (mg mg-1 phosphate) compared with a single system, DMT-HFO, in 168 h. For the desorption experiment carried out with soil solution, the data fitted fairly well with first order kinetics for both sorbents (R2 = 0.946-0.998), the amount adsorbed by DMT-HFAO being greater than DMT-HFO. The soil data fitted an intra-particle diffusion model fairly well for both sorbents (R2 = 0.98-0.992) with rate constants, kp, following the order: DMT-HFAO > DMT-HAFAO > DMT-HFO. The DMT-HFAO approach also showed better fit to the two component first order model (R2 = 0.994 & 0.997) indicating that the modified method has promising potential for a long-term phosphate desorption kinetics study from soil, the implication of which is important both from agricultural and environmental perspectives. However, correlation of the P adsorbed by this sink method with actual plant P uptake in various soils should be carried out to validate the universality of this technique.

Evidence for circulation of the rift valley fever virus among livestock in the union of Comoros.

Rift Valley fever virus (RVFV) is an arthropod-borne phlebovirus reported to be circulating in most parts of Africa. Since 2009, RVFV has been suspected of continuously circulating in the Union of Comoros. To estimate the incidence of RVFV antibody acquisition in the Comorian ruminant population, 191 young goats and cattle were selected in six distinct zones and sampled periodically from April 2010 to August 2011. We found an estimated incidence of RVFV antibody acquisition of 17.5% (95% confidence interval (CI): [8.9-26.1]) with a significant difference between islands (8.2% in Grande Comore, 72.3% in Moheli and 5.8% in Anjouan). Simultaneously, a longitudinal entomological survey was conducted and ruminant trade-related information was collected. No RVFV RNA was detected out of the 1,568 blood-sucking caught insects, including three potential vectors of RVFV mosquito species. Our trade survey suggests that there is a continuous flow of live animals from eastern Africa to the Union of Comoros and movements of ruminants between the three Comoro islands. Finally, a cross-sectional study was performed in August 2011 at the end of the follow-up. We found an estimated RVFV antibody prevalence of 19.3% (95% CI: [15.6%-23.0%]). Our findings suggest a complex RVFV epidemiological cycle in the Union of Comoros with probable inter-islands differences in RVFV circulation patterns. Moheli, and potentially Anjouan, appear to be acting as endemic reservoir of infection whereas RVFV persistence in Grande Comore could be correlated with trade in live animals with the eastern coast of Africa. More data are needed to estimate the real impact of the disease on human health and on the national economy.

A comparative evaluation of immediate dental implant with autogenous versus synthetic guided bone regeneration.

Immediate implant is a placement of the implant immediately into fresh extraction socket site after tooth extraction and is considered to be a predictable and acceptable procedure. The present work is designed to evaluate the periodontal condition after immediate implant placement and the success rate of implant with autogenous versus synthetic guided bone regeneration. Twenty adult male patients with an endodontic failure, tooth fracture decayed tooth (hopeless tooth) were included in this study. Patients were divided into 2 groups: One group (I) received immediate implants augmented with autogenous bone graft, and the other (group II) received immediate implants augmented with a synthetic bone graft. The results revealed that there was a significant difference between the groups for pocket depth and clinical attachment level. The difference between the groups was statistically highly significant only at 12 months (P < .01). In addition, there was statistically significant difference between the groups at 9 and 12 months (P < .001). Moreover, there was significant decrease of marginal bone loss in group I compared with group II (P < .01). In addition, there was statistically significant difference between the both groups at 9 and 12 months for bone density (P < .001). Moreover, there was significant decrease of marginal bone loss in group I compared with group II (P < .01). In conclusion, the immediate dental implant placement with autogenous bone graft showed a significant superiority to synthetic bone graft. In addition, the immediate placement-delayed loaded dental implant remains the procedure of choice for predictable achieving of osseointegration.