204 research outputs found

    Utilization of microbial fuel cells as a dual approach for landfill leachate treatment and power production: a review

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    Landfill leachate, which is a complicated organic sewage water, presents substantial dangers to human health and the environment if not properly handled. Electrochemical technology has arisen as a promising strategy for effectively mitigating contaminants in landfill leachate. In this comprehensive review, we explore various theoretical and practical aspects of methods for treating landfill leachate. This exploration includes examining their performance, mechanisms, applications, associated challenges, existing issues, and potential strategies for enhancement, particularly in terms of cost-effectiveness. In addition, this critique provides a comparative investigation between these treatment approaches and the utilization of diverse kinds of microbial fuel cells (MFCs) in terms of their effectiveness in treating landfill leachate and generating power. The examination of these technologies also extends to their use in diverse global contexts, providing insights into operational parameters and regional variations. This extensive assessment serves the primary goal of assisting researchers in understanding the optimal methods for treating landfill leachate and comparing them to different types of MFCs. It offers a valuable resource for the large-scale design and implementation of processes that ensure both the safe treatment of landfill leachate and the generation of electricity. The review not only provides an overview of the current state of landfill leachate treatment but also identifies key challenges and sets the stage for future research directions, ultimately contributing to more sustainable and effective solutions in the management of this critical environmental issue

    Making sense of Arab labor markets: the enduring legacy of dualism

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    It is well-established that Arab labor markets share certain common characteristics, including an oversized public sector, high unemployment for educated youth, weak private sector dependent on government welfare for their survival, rapid growth in educational attainment, but much of it focused on the pursuit of formal credentials rather than productive skills, and low and stagnant female labor force participation rates. I argue in this paper that all of these features can be explained by the deep and persistent dualism that characterizes Arab labor markets as a result of the use of labor markets by Arab regimes as tool of political appeasement in the context of the authoritarian bargain social contract that they have struck with their citizens in the post-independence period. Even as fiscal crises have long destabilized these arrangements in most non-oil Arab countries, culminating in the dramatic political upheavals of the Arab spring revolutions, the enduring legacy of dualism will continue to strongly shape the production and deployment of human capital in Arab economies for some time. This will undoubtedly pose serious challenges to any efforts to transform these economies into dynamic, rapidly growing and more equitable globally competitive economies

    Status, trends and future dynamics of biodiversity and ecosystems underpinning nature's contributions to people

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    Biodiversity at the species and ecosystem levels is currently under multiple threats almost everywhere in the Asia-Pacific region, and in many areas the situation is now critical (well established). Of the various ecosystems, lowland evergreen forests, alpine ecosystems, limestone karsts, inland wetlands, and estuarine and coastal habitats are most threatened (well established). Genetic diversity within species, both wild and domestic, is also decreasing in many cases as a result of decreasing ranges (established but incomplete). In several countries there has been a small increase in the forest cover which is mostly attributed to monoculture forestry plantations and enabling policies of the governments. Forest fires associated with rapid loss of forest cover is leading to enormous environmental and socio-economic loss (well established) {3.2.1; 3.2.2; 3.2.3; 3.2.4; 3.2.5; 3.3.1}. There has been a steady decline in the populations of large vertebrates due to poaching and illegal trade in wildlife parts and products in the Asia-Pacific region (well established). As a result, most of these species now survive only in the best-managed protected areas (well established). Widespread loss of large vertebrates has had a measureable impact on several forest functions and services, including seed dispersal (established but incomplete). Australia has the highest rate of mammal extinction (>10 per cent) of any continent globally. Bird extinctions on individual Pacific islands range from 15.4 per cent to 87.5 per cent for those with good fossil records, and these extinctions have resulted in the loss of many ecological functions previously performed by birds (well established). Besides wildlife, there is a massive regional trade in timber, traditional medicines and other products (well established). Without adequate protection, remediation and proper policies, the current decline in biodiversity and nature's contributions to people on land, in freshwaters, and in the sea will threaten the quality of life of future generations in the Asia-Pacific region {3.2.1.1; 3.2.1.2; 3.2.1.4; 3.2.1.7; 3.2.2.1; 3.3.1} With the current rate of human population growth, expansion of urban industrial environments, transformation of agriculture in favour of high yielding varieties, transforming forests to uniform plantations of oil palm, rubber or timber trees, the biodiversity and nature's contributions to people in the Asia-Pacific region are likely to be adversely affected in the coming decades (well established). It is predicted that most of the biodiversity in the next few decades may be confined to protected areas or in places where the local communities have taken the lead in local level conservation in lieu of economic incentives and equitable compensation by the stake-holders. Unprecedented increase in human population of the Asia-Pacific region has stressed the fragile ecosystems to their limits; while arable cropping has been extended to sites which were not entirely suitable for it, resulting in soil degradation and erosion (well established) {3.2.1.1; 3.2.1.2; 3.2.1.5; 3.2.2.2; 3.2.2.4; 3.3; 3.3.1; 3.3.6; 3.4}. Freshwater ecosystems in the Asia-Pacific region support more than 28 per cent of aquatic and semi-aquatic species but nearly 37 per cent of these species are threatened due to anthropogenic and climatic drivers (well established). Cumulative impacts of global warming and damming of rivers in some of the river basins will have significant negative impacts on fish production and environmental flows (well established). Likewise, degradation of wetlands has had severe negative impacts on migratory waterfowl, fish production and local livelihoods (well established). However, there are scientific data gaps on the current status of biodiversity and nature's contributions to people in most of the river basins, inland wetlands and peatlands of the region {3.2.2.1; 3.2.2.2; 3.2.2.3; 3.2.2.4}. Coastal and marine habitats are likewise threatened due to commercial aquaculture, overfishing, and pollution affecting biodiversity and nature's contributions to people (well established). Detailed analyses of fisheries production in the region have shown severe decline in recent decades. It is projected that if unsustainable fishing practices continue, there could be no exploitable stocks of fish by as early as 2048. This could lead to trophic cascades and collapse of marine ecosystems (established but incomplete). Loss of seagrass beds which forms main diet of several threatened species such as dugong is a major concern (well established). There is a need to conduct systematic and region-wide assessment of fisheries stocks and coastal habitat in the region to aid conservation, management and restoration. {3.1.3.1; 3.2.3.3; 3.2.3.6; 3.2.4.6; 3.4}. Mangrove ecosystems in the Asia-Pacific region are most diverse in the world. They support a rich biodiversity and provide a range of provisioning, regulating and supporting services, which are crucial for the livelihood of local communities (well established). Both mangrove and intertidal habitats form a buffer from siltation for offshore coral reefs protection hence affecting productivity of reefs including seagrass. However, up to 75 per cent of the mangroves have been degraded or converted in recent decades (well established). The conversion of mangroves to aquaculture, rice, oil palm, and other land-use changes is leading to the loss of the buffer between sea and land which can reduce the impact of natural disasters such as cyclones and tsunamis. It is projected that rise in sea level due to global warming would pose the biggest threat to mangroves, thereby affecting nature's contributions to people especially in Bangladesh, Philippines, New Zealand, Viet Nam and China (well established) {3.2.3.1; 3.2.3.2; 3.3.4}. There has been a steady increase in the number, abundance and impacts of invasive alien species in the Asia-Pacific region, negatively affecting native biodiversity, ecosystem functioning and socio-cultural environments (well established). The total annual loss caused by invasive alien species has been estimated at US35.5billioninSEAsiaandUS35.5 billion in SE Asia and US9B in Australia. Costs to agriculture due to invasive alien species are likewise immense in the region {3.2.1.1; 3.2.1.2; 3.2.1.4; 3.2.1.5; 3.2.1.6; 3.2.1.7; 3.2.2.1; 3.2.2.2; 3.2.2.3; 3.2.3.6; 3.3.5}. There has been a nearly 30 per cent decline in biocultural diversity in the Asia-Pacific region since the 1970s (well established). Decline of linguistic diversity has been catastrophic in the indigenous Australian and Trans-New Guinean families, as a result of a shifting away from small indigenous languages towards larger, national or regional languages (well established). Linguistic and biological diversity often coincide in the Asia-Pacific region and parallel strategies need to be developed for their conservation. National conservation priorities should take into consideration the bioculturally rich areas that are facing great threats {3.2.5; 3.2.5.2; 3.2.5.4; 3.4}. Protected Area coverage in the Asia-Pacific region has increased substantially since last three decades. Despite this progress, however, at least 75 per cent of Key Biodiversity Areas remain unprotected, suggesting that the region is not on track to conserve areas of particular importance for biodiversity, as called for under Aichi Target 11 (well established). Oceania has the highest overall Protected Area coverage in the region. North-East Asia has the highest proportion of Key Biodiversity Areas covered by Protected Areas, but only 1 per cent of its marine area is protected (well established) {3.2.5.6; 3.2.6; 3.2.6.1}. The Asia-Pacific region has high levels of endemism, and some 25 per cent of the region’s endemic species are facing high extinction risks as per the IUCN Red List. Endemic species in some subregions face an extinction risk as high as 46 per cent of endemic species threatened in South Asia (well established). South-East Asia has the greatest number of threatened species and the fastest increases in extinction risk (Red List Index) in the Asia-Pacific region. North Asian endemic species extinction risk is also higher than the regional average; the high percentage of Data Deficient species (36 per cent) indicates that more research and conservation action are needed for endemic species in this subregion (well established) {3.2.1; 3.2.2; 3.2.6.2; 3.3.4}. Some aspects of biodiversity have recently started to recover in several countries in the Asia-Pacific region (established but incomplete). This recovery has resulted from various changes, including population concentration in cities, increased agricultural production per unit area, increasing conservation awareness among citizens, and the enabling policies of the governments. Future trends of biodiversity in the Asia-Pacific region will largely depend on whether other countries will follow this recovering trajectory by stabilizing land/sea use change, manage their natural resources sustainably, and cooperating with each other in meeting the Aichi Targets and the Sustainable Development Goals {3.2.1.5; 3.2.3.5; 3.3.1; 3.3.3; 3.3.6}. Given that the scientific information on the status and trends of biodiversity and nature's contributions to people is not available uniformly across all ecosystems and habitats in the region, the national governments are encouraged to initiate systematic documentation and monitoring of health of ecosystems and ecosystem flows (established but incomplete). Saving terrestrial fauna especially big mammals and other fauna that require large roaming areas such as Orangutans, proboscis monkey, hornbills, tigers, Sumatran rhinoceros, gaurs and Asian elephants can be done by connecting large tracts of forests with wildlife corridors or through rehabilitation projects; the same goes for coastal and marine, freshwater and other ecosystems in the region {3.2.1.1; 3.2.2.4; 3.3.4; 3.4}

    Successful treatment of Candida parapsilosis mural endocarditis with combined caspofungin and voriconazole

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    BACKGROUND: Fungal mural endocarditis is a rare entity in which the antemortem diagnosis is seldom made. Seven cases of mural endocarditis caused by Candida spp. have been collected from literature and six of these patients died after treatment with amphotericin B. CASE PRESENTATION: We report a case of mural endocarditis diagnosed by transesophageal echocardiogram and positive blood cultures to Candida parapsilosis. Because blood cultures continued to yield C. parapsilosis despite caspofungin monotherapy, treatment with voriconazole was added. CONCLUSION: This is the first description of successful treatment of C. parapsilosis mural endocarditis with caspofungin and voriconazole

    Iron Status Predicts Treatment Failure and Mortality in Tuberculosis Patients: A Prospective Cohort Study from Dar es Salaam, Tanzania

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    Experimental data suggest a role for iron in the course of tuberculosis (TB) infection, but there is limited evidence on the potential effects of iron deficiency or iron overload on the progression of TB disease in humans. The aim of the present analysis was to examine the association of iron status with the risk of TB progression and death.\ud We analyzed plasma samples and data collected as part a randomized micronutrient supplementation trial (not including iron) among HIV-infected and HIV-uninfected TB patients in Dar es Salaam, Tanzania. We prospectively related baseline plasma ferritin concentrations from 705 subjects (362 HIV-infected and 343 HIV-uninfected) to the risk of treatment failure at one month after initiation, TB recurrence and death using binomial and Cox regression analyses. Overall, low (plasma ferritin<30 µg/L) and high (plasma ferritin>150 µg/L for women and>200 µg/L for men) iron status were seen in 9% and 48% of patients, respectively. Compared with normal levels, low plasma ferritin predicted an independent increased risk of treatment failure overall (adjusted RR = 1.95, 95% CI: 1.07 to 3.52) and of TB recurrence among HIV-infected patients (adjusted RR = 4.21, 95% CI: 1.22 to 14.55). High plasma ferritin, independent of C-reactive protein concentrations, was associated with an increased risk of overall mortality (adjusted RR = 3.02, 95% CI: 1.95 to 4.67). Both iron deficiency and overload exist in TB patients and may contribute to disease progression and poor clinical outcomes. Strategies to maintain normal iron status in TB patients could be helpful to reduce TB morbidity and mortality

    XIAP Protection of Photoreceptors in Animal Models of Retinitis Pigmentosa

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    BACKGROUND: Retinitis pigmentosa (RP) is a blinding genetic disorder that is caused by the death of photoreceptors in the outer nuclear layer of the retina. To date, 39 different genetic loci have been associated with the disease, and 28 mutated genes have been identified. Despite the complexity of the underlying genetic basis for RP, the final common pathway is photoreceptor cell death via apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: In this study, P23H and S334ter rhodopsin transgenic rat models of RP were used to test the neuroprotective effects of anti-apoptotic gene therapy. Adeno-associated viruses (AAV) carrying the X-linked inhibitor of apoptosis (XIAP) or green fluorescent protein (GFP) were delivered subretinally into the eye of transgenic rat pups. Histological and functional measures were used to assess neuroprotection. XIAP is known to block apoptosis by inhibiting the action of caspases-3, -7 and -9. The results show that XIAP gene therapy provides long-term neuroprotection of photoreceptors at both structural and functional levels. CONCLUSIONS/SIGNIFICANCE: Our gene therapy strategy targets the apoptotic cascade, which is the final common pathway in all forms of retinitis pigmentosa. This strategy holds great promise for the treatment of RP, as it allows for the broad protection of photoreceptors, regardless of the initial disease causing mutation

    Oral treatment with a zinc complex of acetylsalicylic acid prevents diabetic cardiomyopathy in a rat model of type-2 diabetes: activation of the Akt pathway.

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    BACKGROUND: Type-2 diabetics have an increased risk of cardiomyopathy, and heart failure is a major cause of death among these patients. Growing evidence indicates that proinflammatory cytokines may induce the development of insulin resistance, and that anti-inflammatory medications may reverse this process. We investigated the effects of the oral administration of zinc and acetylsalicylic acid, in the form of bis(aspirinato)zinc(II)-complex Zn(ASA)2, on different aspects of cardiac damage in Zucker diabetic fatty (ZDF) rats, an experimental model of type-2 diabetic cardiomyopathy. METHODS: Nondiabetic control (ZL) and ZDF rats were treated orally with vehicle or Zn(ASA)2 for 24 days. At the age of 29-30 weeks, the electrical activities, left-ventricular functional parameters and left-ventricular wall thicknesses were assessed. Nitrotyrosine immunohistochemistry, TUNEL-assay, and hematoxylin-eosin staining were performed. The protein expression of the insulin-receptor and PI3K/AKT pathway were quantified by Western blot. RESULTS: Zn(ASA)2-treatment significantly decreased plasma glucose concentration in ZDF rats (39.0 +/- 3.6 vs 49.4 +/- 2.8 mM, P < 0.05) while serum insulin-levels were similar among the groups. Data from cardiac catheterization showed that Zn(ASA)2 normalized the increased left-ventricular diastolic stiffness (end-diastolic pressure-volume relationship: 0.064 +/- 0.008 vs 0.084 +/- 0.014 mmHg/microl; end-diastolic pressure: 6.5 +/- 0.6 vs 7.9 +/- 0.7 mmHg, P < 0.05). Furthermore, ECG-recordings revealed a restoration of prolonged QT-intervals (63 +/- 3 vs 83 +/- 4 ms, P < 0.05) with Zn(ASA)2. Left-ventricular wall thickness, assessed by echocardiography, did not differ among the groups. However histological examination revealed an increase in the cardiomyocytes' transverse cross-section area in ZDF compared to the ZL rats, which was significantly decreased after Zn(ASA)2-treatment. Additionally, a significant fibrotic remodeling was observed in the diabetic rats compared to ZL rats, and Zn(ASA)2-administered ZDF rats showed a similar collagen content as ZL animals. In diabetic hearts Zn(ASA)2 significantly decreased DNA-fragmentation, and nitro-oxidative stress, and up-regulated myocardial phosphorylated-AKT/AKT protein expression. Zn(ASA)2 reduced cardiomyocyte death in a cellular model of oxidative stress. Zn(ASA)2 had no effects on altered myocardial CD36, GLUT-4, and PI3K protein expression. CONCLUSIONS: We demonstrated that treatment of type-2 diabetic rats with Zn(ASA)2 reduced plasma glucose-levels and prevented diabetic cardiomyopathy. The increased myocardial AKT activation could, in part, help to explain the cardioprotective effects of Zn(ASA)2. The oral administration of Zn(ASA)2 may have therapeutic potential, aiming to prevent/treat cardiac complications in type-2 diabetic patients

    Candida dubliniensis: An Appraisal of Its Clinical Significance as a Bloodstream Pathogen

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    A nine-year prospective study (2002–2010) on the prevalence of Candida dubliniensis among Candida bloodstream isolates is presented. The germ tube positive isolates were provisionally identified as C. dubliniensis by presence of fringed and rough colonies on sunflower seed agar. Subsequently, their identity was confirmed by Vitek2 Yeast identification system and/or by amplification and sequencing of the ITS region of rDNA. In all, 368 isolates were identified as C. dubliniensis; 67.1% came from respiratory specimens, 11.7% from oral swabs, 9.2% from urine, 3.8% from blood, 2.7% from vaginal swabs and 5.4% from other sources. All C. dubliniensis isolates tested by Etest were susceptible to voriconazole and amphotericin B. Resistance to fluconazole (≥8 µg/ml) was observed in 2.5% of C. dubliniensis isolates, 7 of which occurred between 2008–2010. Of note was the diagnosis of C. dubliniensis candidemia in 14 patients, 11 of them occurring between 2008–2010. None of the bloodstream isolate was resistant to fluconazole, while a solitary isolate showed increased MIC to 5-flucytosine (>32 µg/ml) and belonged to genotype 4. A review of literature since 1999 revealed 28 additional cases of C. dubliniensis candidemia, and 167 isolates identified from blood cultures since 1982. In conclusion, this study highlights a greater role of C. dubliniensis in bloodstream infections than hitherto recognized
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