Using SF and CKD as cement replacement materials for producing cement mortar

When considering binding materials, cement mortar is thought to be one of the most conventional and effective materials. The cement mortar is mainly containing cement, sand (fine and rough), and water. In fact, there are many environmental and economical limitations to the usage of raw materials in mortar blends. For considering these limitations, many researchers studied the ability to incorporate waste-materials to fully or partially replace conventional raw materials. In this research, compressive strength and ultrasonic pulse velocity (UPV) will be studied by incorporating (SF) and (CKD) of mortar specimens and study the effect after 7,14, and 28 days. The obtained results from the collected samples (M1, M2, and M3) were compared with the reference mortar samples that contain ordinary Portland cement (OPC) only. The collected results showed that samples with CKD and SF have less compressive strength than ones with OPC with 28 days of curing. In addition, with higher CKD content, lower compressive strength was obtained. Samples (M1, M2) have the highest (UPV) values at different curing periods

Associations between Season and Gametocyte Dynamics in Chronic Plasmodium falciparum Infections

Introduction: In a markedly seasonal malaria setting, the transition from the transmission-free dry season to the transmission season depends on the resurgence of the mosquito population following the start of annual rains. The sudden onset of malaria outbreaks at the start of the transmission season suggests that parasites persist during the dry season and respond to either the reappearance of vectors, or correlated events, by increasing the production of transmission stages. Here, we investigate whether Plasmodium falciparum gametocyte density and the correlation between gametocyte density and parasite density show seasonal variation in chronic (largely asymptomatic) carriers in eastern Sudan. Materials and Methods: We recruited and treated 123 malaria patients in the transmission season 2001. We then followed them monthly during four distinct consecutive epidemiological seasons: transmission season 1, transmission-free season, pre-clinical period, and transmission season 2. In samples collected from 25 participants who fulfilled the selection criteria of the current analysis, we used quantitative PCR (qPCR) and RT-qPCR to quantify parasite and gametocyte densities, respectively. Results and Discussion: We observed a significant increase in gametocyte density and a significantly steeper positive correlation between gametocyte density and total parasite density during the pre-clinical period compared to the preceding transmission-free season. However, there was no corresponding increase in the density or prevalence of total parasites or gametocyte prevalence. The increase in gametocyte production during the pre-clinical period supports the hypothesis that P. falciparum may respond to environmental cues, such as mosquito biting, to modulate its transmission strategy. Thus, seasonal changes may be important to ignite transmission in unstable-malaria settings

Population dynamics of Plasmodium falciparum in an unstable malaria area of eastern Sudan.

The Plasmodium falciparum population in Asar village, eastern Sudan, where malaria transmission is markedly seasonal, was monitored monthly over a period of 15 months. A cohort of infected patients was treated and then followed monthly throughout the dry season until the next transmission season. Parasitaemia detected by microscopy among the cohort reduced dramatically following treatment, but remained sporadic during the dry season, and reappeared following the onset of the next wet season. However between 40 and 50% of the cohort retained a persisting parasitaemia detectable by PCR throughout the dry season. These parasites were genetically complex, consisting of multiple clones with a large repertoire of alleles of the studied genes. While the number of clones per host dropped significantly following treatment of acute cases during the transmission season, drug treated people nevertheless maintained an average of one clone throughout the dry season. Allele frequencies of MSP-1, MSP-2 and GLURP showed slight, statistically insignificant, fluctuations between the dry and wet seasons. A higher frequency of inbreeding was estimated among the parasites that survived the dry season compared to the wet season

Local differentiation in Plasmodium falciparum drug resistance genes in Sudan.

Studies of population genetic structure of parasites can be used to infer which parasite genes are under selection. Here, the population structure of 4 genes associated with drug resistance of Plasmodium falciparum (the chloroquine resistance transporter, pfcrt, dihydrofolate reductase, dhfr, dihydropteroate synthase, dhps, and multi-drug resistance, pfmdr-1) were examined in parasite populations in 3 villages in eastern Sudan and in an urban area of Khartoum, the capital. In order to differentiate the effects of drug selection from neutral influences on population structure, parasites were also genotyped for 3 putatively neutral microsatellite loci (polyalpha, TA81 and pfg377), and for 2 antigenic loci that are either under balancing selection or neutral, merozoite surface protein 1 and 2, (MSP-1 and MSP-2). Cross-sectional surveys were carried out during the peak transmission (wet) season and in the ensuing dry season. No significant variation in frequencies of MSP-1 and MSP-2 alleles was seen among villages in the eastern region and between the villages and Khartoum, nor between the wet and dry season. However, the drug resistance genes, pfmdr-1, pfcrt and dhfr and to a lesser extent the microsatellite loci showed high FST values when comparing villages with Khartoum, indicating strong geographical differentiation at these loci. Moreover, variation in frequencies of the drug resistance genes, pfmdr-1, pfcrt and dhfr, was observed between the wet and dry season. These differences most probably reflect the variation in drug pressure between each region, and in drug usage between the wet and dry season in a given region

Phosphate removal from water using bottom ash: Adsorption performance, coexisting anions and modelling studies

Phosphate in freshwater possesses significant effects on both quality of water and human health. Hence, many treatment methods were used to remove phosphate from water/wastewaters, such as biological and electrochemical methods. Recent researches demonstrated that adsorption approaches are convenient solutions for water/wastewater remediation from phosphate. Thus, the present study employs industrial by-products (bottom ash (BA)), as a cost-effective and eco-friendly alternative, to remediate water from phosphate in the presence of competitor ions (humic acid). This study was initiated by characterising the chemical and physical properties of the BA, sample, then the Central Composite Design (CCD) was utilised to design the required batch experiments and to model the influence of solution temperature (ST), humic acid concentration (HAC), pH of the solution (PoS) and doses of adsorbent (DoA) on the performance of the BA. Langmuir model was utilised to assess the adsorption process. The outcomes of this study evidenced that the BA removed 83.8% of 5.0 mg/l of phosphates at ST, HAC, PoS and DoA 35 oC, 20 mg/L, 5 and 55 g/L, respectively. The isotherm study indicated a good affinity between BA and phosphate. Additionally, the developed model, using the CCD, reliably simulated the removal of phosphates using BA (R2= 0.99)

MODIS Observations of Human-Induced Changes in the Mesopotamian Marshes in Iraq

With a total area of \u3e7,750 km2, the Mesopotamian marshes near the border between Iraq and Iran provide habitats for millions of birds and most of the commercial fisheries in this region. Beginning in the 1990s, human activities such as war, dam construction, restoration, and water supply diversions significantly influenced the ecosystems. Yet, to date only a handful of reports document changes in the marshes, all using field measurements or sporadic satellite observations. Here, using long-term MODIS observations between 2000 and 2012 we quantified the annual changes and long-term trends in both the vegetation and water coverage (i.e., the areas of vegetation and water) in the Al-Hammar, Al-Huwaiza, and the Central marshes, the three major marshes in this region. In addition to seasonality, the most notable patterns are the three distinctive regimes within the observation period: the 2000–2003 regime for low coverage of both vegetation and water, the 2004–2008 regime for significantly increased coverage, and the 2009–2012 regime for reduced coverage (almost back to the 2000–2003 levels). Relative to the 2000–2003 regime, increases in the vegetation coverage during 2004–2008 ranged from 50 to \u3e100 %. It is likely that these changes are the result of human induced activities, with weather fluctuations (e.g., precipitation) playing a minor role. Continuous and sustainable monitoring through combining satellite and field measurements is required to fully understand the consequences of such changes as well as to evaluate the impacts of future restoration programs