Selective catalytic reduction of NO over hierarchical Cu ZSM-5 coated on an alumina foam support

Hydrothermal coating of hierarchical Cu ZSM-5 catalyst on alumina foam.

A case analysis of a mass treatment approach to control GI and water-related conditions in Sudan

Background

The efficiency of mass chlorination in controlling diarrheal diseases during acute emergencies has been extensively reported in literature. However, long-term crises received unparallel attention. Researchers have previously carried out a trial that investigated the impact of using chemical means to treat water reservoirs of Um-Baddah Nevachah, a refugee camp located in the western outskirts of Khartoum, Sudan.

A double-blind community experimental trial was carried out by randomly adding either chlorine or a placebo to the major water tanks in the area. Data were collected using a mixed-methods study design. The primary input was the quantitative data derived from total coliforms lab tests and records of the local primary healthcare center, while the embedded (nested) portion generated most of the qualitative data from direct face-to-face interviews.

As a case analysis, this study aims to critically appraise the original trial. In the Background the authors discussed the context of the trial, approach used, and outcomes. Discussion section included three issues related to the trial: scientific importance, challenges and strategies.

Discussion

Importance: There are two factors that contribute to the importance of this study: First, the integrated and systematic approach followed to resolve associated challenges. The study swiftly moved from investigating potential water contamination, to test whether it is related to an endogenous focus that auto-taints drinking water, and finally it explored the impact of tanks chlorination on public health. Second, the longstanding humanitarian context which remains largely underreported in literature. Challenges: funding limitations were among the first obstacles faced. During the fieldwork preparation phase, a lot of work was required to resolve logistical and security challenges. Keeping volunteers motivated was the biggest concern during the last phase of data collection. Strategies: The “Matrix Solutions Strategy” was developed and used to optimize scarce resources to simultaneously target multiple problems through a single intervention.

Conclusion

Key lessons learned from the whole experience were: persistence is paramount for the success of studies in precarious situations; lateral thinking generates alternative solutions that are novel, feasibility and practical in resources-limited settings; and finally respecting local culture and regulations is essential for building trust with both authorities and vulnerable societies.

Numerical analysis of mixing chamber non-uniformities and feed conditions for optimal performance of urea SCR

Non-uniform ammonia concentration distribution in urea SCR.

Reservoir Chlorination of the Local Well-Tank-Faucet Systems is a Rapid and Efficient Tool for Controlling Water-related Diseases: Pathogens' Load-clinical Response Rate Correlation

Chlorination is a chemical method for water disinfection that has been proved to be highly effective in controlling waterborne diarrheal diseases. Most studies have focused on wells’ chlorination or later at household level, whereas there have been relatively few researches evaluating the treatment of reservoirs water. Our study followed a mixed design with a before-and-after comparison. It was conducted in a refugee settlement, Um-Baddah Nevachah, which is located in the western outskirts of Khartoum, Sudan. Baseline total coliform test findings have paired areas of four wells that were labeled as sample or control based on fair coin-tossing. A centrally administered water treatment that contains chlorine was added to intervention wells, whereas the other set was considered as chlorine-free placebo. Data were collected 15 days later from the following four main sources: total coliform count, questionnaire-based experimental data trackers, health center records, and face-to-face interviews. The calculated sample size was 341 with corresponding controls selected by systematic random sampling. We found that both groups’ prevalences of waterborne diseases were significantly different before the intervention and they shifted later (p = 0.043 vs. p = 0.496, 95% CI). These findings suggest that reservoir chlorination provides prompt disinfection of well-tank-faucet systems water. Highly credible gastroenteritis is a useful tool to detect cases of gastroenteritis in resources limit settings.

Fluorescence of coral larvae predicts their settlement response to crustose coralline algae and reflects stress

Multi-coloured homologues of the green fluorescent protein generate some of the most striking visual phenomena in the ocean. Despite their natural prominence in reef-building corals and widespread use in biotechnology, their biological role remains obscure. Here, we experimented with larvae of Acropora millepora to determine what can be learned about a coral larva or recruit from its fluorescent colour. We performed 12 crosses between seven A. millepora colonies representing differing fluorescence phenotypes, the larvae of which were exposed to a natural settlement cue (crustose coralline algae) and heat-light stress. Parental effects explained 18 per cent of variation in colour and 47 per cent of variation in settlement. The colour of the larval family emerged as a predictor of the settlement success: redder families were significantly less responsive to the provided settlement cue (p = 0.006). This relationship was owing to a correlation between parental effects on settlement and colour (r(2) = 0.587, p = 0.045). We also observed pronounced (16%) decline in settlement rate, as well as subtle (2%), but a statistically significant decrease in red fluorescence, as a consequence of heat-light stress exposure. Variation in settlement propensity in A. millepora is largely owing to additive genetic effects, and is thought to reflect variation in dispersal potential. Our results suggest an optical signature to discriminate between long- and short-range dispersing genotypes, as well as to evaluate stress. Further research in this direction may lead to the development of field applications to trace changes in coral life history and physiology caused by global warming.

Non-mammalian fat-1 gene prevents neoplasia when introduced to a mouse hepatocarcinogenesis model: Omega-3 fatty acids prevent liver neoplasia

We investigated the effect of a non-mammalian omega-3 desaturase in a mouse hepatocarcinogenesis model. Mice containing double mutations (DM) in c-myc and TGF-alpha (transforming growth factor-alpha), leading to liver neoplasia, were crossed with mice containing omega-3 desaturase. MRI analysis of triple mutant (TM) mice showed the absence of neoplasia at all time points for 92% of mice in the study. Pathological changes of TM (TGFalpha/c-myc/fat-1) mouse liver tissue was similar to control mouse liver tissue. Magnetic resonance spectroscopy (MRS) measurements of unsaturated fatty acids found a significant difference (p<0.005) between DM and TM transgenic (Tg) mice at 34 and 40 weeks of age. HPLC analysis of mouse liver tissue revealed markedly decreased levels of omega-6 fatty acids in TM mice when compared to DM (TGFalpha/c-myc) and control (CD1) mice. Mass spectrometry (MS) analysis indicated significantly decreased 16:0/20:4 and 18:1/20:4 and elevated 16:0/22:6 fatty acyl groups in both GPCho and GPEtn, and elevated 16:0/20:5, 18:0/18:2, 18:0/18:1 and 18:0/22:6 in GPCho, within TM mice compared to DM mice. Total fatty acid analysis indicated a significant decrease in 18:1n9 in TM mice compared to DM mice. Western blot analysis of liver tissue showed a significant (p<0.05) decrease in NF-kappaB (nuclear factor-kappaB) levels at 40 weeks of age in TM mice compared to DM mice. Microarray analysis of TM versus DM mice livers at 40 weeks revealed alterations in genes involved in cell cycle regulation, cell-to-cell signaling, p53 signaling, and arachidonic acid (20:4) metabolism. Endogenous omega-3 fatty acids were found to prevent HCC development in mice.

Fluorescent pigments in corals are photoprotective

All reef-forming corals depend on the photosynthesis performed by their algal symbiont, and such corals are therefore restricted to the photic zone. The intensity of light in this zone declines over several orders of magnitude--from high and damaging levels at the surface to extreme shade conditions at the lower limit. The ability of corals to tolerate this range implies effective mechanisms for light acclimation and adaptation. Here we show that the fluorescent pigments (FPs) of corals provide a photobiological system for regulating the light environment of coral host tissue. Previous studies have suggested that under low light, FPs may enhance light availability. We now report that in excessive sunlight FPs are photoprotective; they achieve this by dissipating excess energy at wavelengths of low photosynthetic activity, as well as by reflecting of visible and infrared light by FP-containing chromatophores. We also show that FPs enhance the resistance to mass bleaching of corals during periods of heat stress, which has implications for the effect of environmental stress on the diversity of reef-building corals, such as enhanced survival of a broad range of corals allowing maintenance of habitat diversity.

Does open-access mammography and ultrasound delay the diagnosis of breast cancer?

There is a consensus that open-access breast imaging for general practitioners is inappropriate since the process omits an expert clinical examination and fine needle aspiration cytology. However, it was decided to test this hypothesis by comparing the outcome of breast referrals in a district with both an open-access imaging and a one-stop clinic. The time from referral to definitive diagnosis in all women with breast cancer was compared over a 12 month period in 1996. Of 1049 women referred for open-access imaging 20 (2%) were found to have breast cancer compared with 91 (9%) of 995 women referred to the one-stop breast clinic. There was a longer interval before the diagnosis of breast cancer was made in cases referred for open-access imaging compared with cases referred to the one-stop breast clinic (mean 63 vs 35 days). However, if patients with advanced disease are excluded the mean interval was 63 vs 44 days. The mean tumour size of breast cancers in cases referred to open-access imaging was smaller (1.5 vs 2.3 cm), there were fewer grade 3 tumours (10% vs 39%), and there was a lower rate of axillary lymph node metastases (20% vs 32%) compared with cases referred to the one-stop breast clinic. The longer interval for the open-access patients was largely due to administrative delay and the 3 patients with a delay of more than 3 months had all had a triple assessment which was false negative. This study does not support the hypothesis that open-access mammography is unsafe and should be withdrawn.

Molluscicidal saponins from Catunaregam nilotica

Two new saponins were isolated from the fruits of Catunaregam nilotica Stapf, syn. Lachnosiphonium nilotica; Randia nilotica; Xeromphis nilotica. Their structures were determined mainly by spectroscopic methods as 3- O-[O-alpha-L-rhamnopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1 -->3)]- beta-D-glucopyranosyl]oleanolic acid and 28-O-beta-D- glucopyranosyl-3-O-[O-alpha-L-rhamnopyranosyl-(1-->3)-O[O-beta-D- glucopyranosyl]-beta-D-glycopyranosyl]oleanolate. The monodesmosidic saponin is a potent molluscicide against the schistosomiasis transmitting snail Biomphalaria glabrata with a LC50 value of 3 ppm. In addition two known saponins, 3-O-[2', 3'-di-O-(beta-D-glucopyranosyl)-beta-D- glucopyranosyl]oleanolic acid and 3-O-[O-beta-D-glucopyranosyl(1-->3)- beta-D-glucopyranosyl]oleanolic acid, were identified and their molluscicidal activity determined, the LC50 values being 26 and 3 ppm, respectively. Initial molluscicidal screening of the crude water and ethanol extracts revealed 100% snail mortality at concentrations of 100 and 50 ppm, respectively. The haemolytic activity of the molluscicidal saponins was determined as well and the HC50 values towards bovine erythrocytes found to be 3 ppm for the new saponin, and 16 and 2 ppm, respectively, for the two known saponins.