1,669 research outputs found

    Upgrades to ISEFlow: Offloading ARP and supporting IPv6

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    Microcosm testing of municipal sewage and green waste for full-scale remediation of an acid coal pit lake, in semi-arid tropical Australia

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    Pit lakes (abandoned flooded mine pits) represent a potentially valuable water resource to mining companies, the environment and regional communities across arid inland Australia. However, the water is often of low pH with high dissolved metal concentrations. The addition of organic matter to the pit lakes to enhance microbial sulfate reduction is potentially a cost effective and sustainable remediation strategy for these acid waters. However, the cost and availability of sufficient quantities of suitable organic substrates is typically limiting in these remote regions. Nevertheless, small quantities of sewage and green waste (organic garden waste) are often available in these areas from the regional towns which support the mines. This paper reports on preliminary microcosm laboratory experiments in preparation for the treatment of an acid (pH 2.2) coal mine pit lake in semi-arid tropical, inland north Queensland, Australia with municipal treated sewage and green waste. A laboratory experiment using microcosms (acrylic tubes) containing acid pit lake water and sediment were treated as follows; controls (untreated), sewage, green waste and sewage and green waste. The pH increased to a maximum of 5.5 in 145 days in the green waste and sewage treatment, with notable decreases of iron, aluminium and toxic heavy metals. Our results indicated that the green waste was a key component in alkalinity production and heavy metal removal

    Polariton-assisted Singlet Fission in Acene Aggregates

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    Singlet fission is an important candidate to increase energy conversion efficiency in organic photovoltaics by providing a pathway to increase the quantum yield of excitons per photon absorbed in select materials. We investigate the dependence of exciton quantum yield for acenes in the strong light-matter interaction (polariton) regime, where the materials are embedded in optical microcavities. Starting from an open-quantum-systems approach, we build a kinetic model for time-evolution of species of interest in the presence of quenchers and show that polaritons can decrease or increase exciton quantum yields compared to the cavity-free case. In particular, we find that hexacene, a typically poor singlet-fission candidate, can feature a higher yield than cavity-free pentacene when assisted by polaritonic effects. Similarly, we show that pentacene yield can be increased when assisted by polariton states. Finally, we address how various relaxation processes between bright and dark states in lossy microcavities affect polariton photochemistry. Our results also provide insights on how to choose microcavities to enhance similarly related chemical processes.Comment: 12 pages, 4 figure

    The Quest for Anti-inflammatory and Anti-infective Biomaterials in Clinical Translation.

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    Biomaterials are now being used or evaluated clinically as implants to supplement the severe shortage of available human donor organs. To date, however, such implants have mainly been developed as scaffolds to promote the regeneration of failing organs due to old age or congenital malformations. In the real world, however, infection or immunological issues often compromise patients. For example, bacterial and viral infections can result in uncontrolled immunopathological damage and lead to organ failure. Hence, there is a need for biomaterials and implants that not only promote regeneration but also address issues that are specific to compromised patients, such as infection and inflammation. Different strategies are needed to address the regeneration of organs that have been damaged by infection or inflammation for successful clinical translation. Therefore, the real quest is for multifunctional biomaterials with combined properties that can combat infections, modulate inflammation, and promote regeneration at the same time. These strategies will necessitate the inclusion of methodologies for management of the cellular and signaling components elicited within the local microenvironment. In the development of such biomaterials, strategies range from the inclusion of materials that have intrinsic anti-inflammatory properties, such as the synthetic lipid polymer, 2-methacryloyloxyethyl phosphorylcholine (MPC), to silver nanoparticles that have antibacterial properties, to inclusion of nano- and micro-particles in biomaterials composites that deliver active drugs. In this present review, we present examples of both kinds of materials in each group along with their pros and cons. Thus, as a promising next generation strategy to aid or replace tissue/organ transplantation, an integrated smart programmable platform is needed for regenerative medicine applications to create and/or restore normal function at the cell and tissue levels. Therefore, now it is of utmost importance to develop integrative biomaterials based on multifunctional biopolymers and nanosystem for their practical and successful clinical translation

    Quantum Transition State Theory for proton transfer reactions in enzymes

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    We consider the role of quantum effects in the transfer of hyrogen-like species in enzyme-catalysed reactions. This study is stimulated by claims that the observed magnitude and temperature dependence of kinetic isotope effects imply that quantum tunneling below the energy barrier associated with the transition state significantly enhances the reaction rate in many enzymes. We use a path integral approach which provides a general framework to understand tunneling in a quantum system which interacts with an environment at non-zero temperature. Here the quantum system is the active site of the enzyme and the environment is the surrounding protein and water. Tunneling well below the barrier only occurs for temperatures less than a temperature T0T_0 which is determined by the curvature of potential energy surface near the top of the barrier. We argue that for most enzymes this temperature is less than room temperature. For physically reasonable parameters quantum transition state theory gives a quantitative description of the temperature dependence and magnitude of kinetic isotope effects for two classes of enzymes which have been claimed to exhibit signatures of quantum tunneling. The only quantum effects are those associated with the transition state, both reflection at the barrier top and tunneling just below the barrier. We establish that the friction due to the environment is weak and only slightly modifies the reaction rate. Furthermore, at room temperature and for typical energy barriers environmental degrees of freedom with frequencies much less than 1000 cm1^{-1} do not have a significant effect on quantum corrections to the reaction rate.Comment: Aspects of the article are discussed at condensedconcepts.blogspot.co

    HIV/AIDS/STI Surveillance Report:Report Number 21

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    Since the first cases of Acquired Immunodeficiency Syndrome (AIDS) in Tanzania were reported in 1983, the epidemic has evolved from being a rare and new disease to a common household problem, which has affected most Tanzania families. The mainland Tanzania faces a generalized human immunodeficiency virus (HIV) and AIDS epidemic, with an estimated 6.5% of the mainland population infected with HIV (7.7% of adult women and 6.3% of adult men). Overall, 1.4 million Tanzanians (1,300,000 adults and 110,000 children) are living with HIV infection, in a total population of 41 million. The social, economic, and environmental impact of the pandemic is sorely felt as an estimated 140,000 Tanzanians have perished, leaving behind as estimated 2.5 million orphans and vulnerable children, representing approximately 10-12% of all Tanzanian children. As elsewhere in sub-Saharan African, the underlying factors of poverty, migration, marginalization, lack of information and skills, disempowerment, and poor access to services raise the risk of HIV and have an impact on the course and spread of the pandemic. Close to 85% of HIV transmission in Tanzania occurs through heterosexual contact, less than 6% through mother-to-child transmission, and less than 1% through blood transfusion. There continues to be a significant difference in the prevalence among urban (10.9%) and rural (5.3%) areas of the country. The National AIDS Control Programme (NACP) of Tanzania was founded in 1987 to champion the health sector response to the HIV epidemic. The primary objectives of the program were to reduce spread of HIV infection, screen blood supplies, enhance clinical services for HIV/AIDS patients and improve STI treatment, prevention of mother-to-child transmission (PMTCT), advocate behavioral change and conduct epidemiologic surveillance and other research. The program phases started with a two-year phase called Short Term Plan\ud (1985-1986). Subsequent phases were termed Medium Term Plans lasting for five-year periods. Through these program phases successful national responses have been identified, the most effective ones being those touching on the major determinants of the epidemic and addressing priority areas that make people vulnerable to HIV infection. These include the following; Since early eighties great efforts have been made to reduce spread of HIV infection through screening of donor blood, advocating behavioral change, condom promotion and improvement of STI treatment. In addition a number of epidemiologic surveillance have been conducted to monitor the trend of HIV infection among different subpopulations e.g. blood donors and pregnant women attending antenatal clinics. In 2004, the National Blood Transfusions Services (NBTS), which is a centralized system of coordinated blood transfusion services, was established. The NBTS is responsible for collection, processing, storage and distribution of safe blood and blood products to health facilities. At the moment NBTS coordinates eight zonal blood transfusion centers, namely Lake Zone-(LZBTC) in Mwanza region, Western-(WZBTC) in Tabora, Northern (NZBTC) in Kilimanjaro region, Eastern (EZBTC) in Dar es Salaam, Southern highlands (SHZBTC) in Mbeya, Southern (SZBTC) in Mtwara and Zanzibar and a military zone –Tanzania People’s Defence Force (TPDF). Since the establishment of NBTS, donated blood in the eight zones is systematically screened for HIV, hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis. The National HIV Care and Treatment Plan (NCTP) was launched in October 2004, with the main focus of a rapid scaling up of HIV care and treatment services, aimed at having more than 400,000 patients on care and treatment by the end of 2008 and, at the same time, follow up disease progression in 1.2 million HIV+ persons who are not eligible for ntiretroviral therapy (ART). Prevention of Mother to Child Transmission of HIV (PMTCT) services were established in 2002 , providing a package of services that include: counseling and testing for pregnant women; short-course preventive ARV regimens to prevent mother-to-child transmission; counseling and support for safe\ud infant feeding practices; family planning counseling or referral; and referral for long-term ART for the\ud child. This report which covers the NACP activities through December 2008 has been arranged in five chapters and is intended for various stakeholders, primarily those working within the health sector.\u

    The Differential Impact of 4Ps on Child Labor Before and During the COVID-19 Pandemic

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    Poverty is widely considered the root cause of child labor in the Philippines. Thus, the Pantawid Pamilyang Pilipino Program (4Ps) was designed to alleviate poverty and reduce child labor through financial assistance, conditional on welfare investments like children’s education. Using 2017, 2019, and 2020 data from the Annual Poverty Indicators Survey (APIS), the study estimated the differential impact of 4Ps on child labor before and during COVID-19 across varying demographic, socio-economic, and locational characteristics. Results from the propensity score matching (PSM) and difference-in-differences (DID) model indicated that since cash transfers cannot fully offset the opportunity cost of children’s education, children of beneficiaries are still likely to work. The findings also revealed that female-led families, households residing in rural areas, and households with family sizes greater than four have a higher likelihood of engaging in child labor. Moreover, despite living above the poverty threshold, households could still be forced to engage in child labor due to increasing inflation rates and declining purchasing powe

    Pawikan on FB: Facebook as a Source of Information on the Current State of Sea Turtles in the Philippines with an Emphasis on Mortality

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    Five of the seven species of pawikan (sea turtles) are found in the Philippine seas. These are Olive ridley turtle (Lepidochelys olivacea), Hawksbill turtle (Eretmochelys imbricata), Green sea (Chelonia mydas), Loggerhead turtle (Caretta caretta), and Leatherback turtle (Dermochelys coriacea). All of these are threatened species due to predation (animals and humans), climate change, harvesting of eggs, juveniles and adults, bycatch, and habitat degradation. Thus, to protect the species, several laws, policies, and programs have been passed and implemented by the Philippines government since 1979 (Marine Wild Fauna Watch of the Philippines (MWFWP), 2014). However, despite the efforts to protect the pawikan, reports about dead sea turtles due to various causes are becoming frequent than ever. Furthermore, public posts on Facebook about dead pawikan by private individuals are increasing. On the other hand, data on the mortality causes of sea turtles remain scarce as of the moment. Hence, to provide additional data, this study was conducted
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