618 research outputs found

    Alternative Land Use Options for Philippine Grasslands: A Bioeconomic Modeling Approach Using the WaNuLCAS Model

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    In the Philippines, pure grasslands occupy 1.8 million ha and another 10.8 million ha (33% of the country’s total land area) is under extensive cultivation mixed with grasslands and scrub. Most of these grasslands are under-utilised and dominated by Imperata cylindrica. Imperata grasslands generally represent areas of degraded soils that are acidic, low in organic matter and susceptible to erosion. However, conversion of these grassland areas into upland farms planted to annual crops and perennial trees is proliferating at a fast rate. This is triggered by the interacting factors of rapidly increasing population, the system of landholding, scarcity of jobs and the declining arable area in the lowlands

    Alternative Land Use Options for Philippine Grasslands: A Bioeconomic Modeling Approach Using the WaNuLCAS Model

    Get PDF
    In the Philippines, pure grasslands occupy 1.8 million ha and another 10.8 million ha (33% of the country\u27s total land area) is under extensive cultivation mixed with grasslands and scrub. Most of these grasslands are under-utilised and dominated by Imperata cylindrica. Imperata grasslands generally represent areas of degraded soils that are acidic, low in organic matter and susceptible to erosion. However, conversion of these grassland areas into upland farms planted to annual crops and perennial trees is proliferating at a fast rate. This is triggered by the interacting factors of rapidly increasing population, the system of landholding, scarcity of jobs and the declining arable area in the lowlands

    Modelling the dynamics of agroforestry adoption in the uplands of Southern Philippines using companion modelling approach

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    A model was developed following an iterative process based on repetitive back-and-forth steps between the model and field activities. A Multi Agent System (MAS) was integrated with a Role-Playing Game (RPG) to understand the dynamics of agroforestry adoption in Claveria, Misamis Oriental. The model simulated and observed different scenarios: cumulative income of agroforestry adopters and non-adopters, impact of market information on farm income, and neighbour effects on the spread of agroforestry adoption. Results of the computer simulations were verified using farmer games and focus group discussions. Agroforestry and non-agroforestry farmers were invited to participate in the role-playing game in order to understand more precisely and validate the model. During the conduct of the role-playing game, the individual behaviour of agents under a number of scenarios and the properties of the system emerging from their interactions were examined and discussed among the players. The model scenarios and role-playing game can serve as a decision support for policymakers, farmers and other stakeholders towards sustainable management of resources. It is envisioned to produce information useful for understanding the decision-making strategies of farmers with regard to agroforestry adoption that can be essential to the success of efforts to address the sustainability of upland areas in the Philippines and elsewhere in south-east Asia

    Ketahanan Deformasi Campuran Beraspal Modifikasi Polimer Hangat Dengan Bahan Aditif Zeolit Alam

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    Polymer modified asphalt mixture can be developed using warm mix technology by adding the mixture using synthetic or natural additives. This mixture can increase the deformation resistance with lower temperature in the process of mixing and compaction. This study proposes the development of warm Polymer Modified Asphalt mix with natural zeolite, which is natural additives from Bayat (Central Java), and the performance of the mixture, in terms of volumetric and mechanical properties, and deformation resistance, which was evaluated using the Marshall method and wheel tracking test. The results showed that the Polymer Modified Asphalt mix with 1 % of natural zeolite have a Marshall stability greater than that of Polymer Modified Asphalt mix without zeolite. Wheel tracking test at 60 °C shows that Polymer Modified Asphalt mix with 1 % of natural zeolite showed better performance than that without zeolite

    Antioxidant potential of bitter cumin (Centratherum anthelminticum (L.) Kuntze) seeds in in vitro models

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    <p>Abstract</p> <p>Background</p> <p>Bitter cumin (<it>Centratherum anthelminticum </it>(L.) Kuntze), is a medicinally important plant. Earlier, we have reported phenolic compounds, antioxidant, and anti-hyperglycemic, antimicrobial activity of bitter cumin. In this study we have further characterized the antioxidative activity of bitter cumin extracts in various in vitro models.</p> <p>Methods</p> <p>Bitter cumin seeds were extracted with a combination of acetone, methanol and water. The antioxidant activity of bitter cumin extracts were characterized in various <it>in vitro </it>model systems such as DPPH radical, ABTS radical scavenging, reducing power, oxidation of liposomes and oxidative damage to DNA.</p> <p>Results</p> <p>The phenolic extracts of bitter cumin at microgram concentration showed significant scavenging of DPPH and ABTS radicals, reduced phosphomolybdenum (Mo(VI) to Mo(V)), ferricyanide Fe(III) to Fe(II), inhibited liposomes oxidation and hydroxyl radical induced damage to prokaryotic genomic DNA. The results showed a direct correlation between phenolic acid content and antioxidant activity.</p> <p>Conclusion</p> <p>Bitter cumin is a good source of natural antioxidants.</p

    Electronic States and Light Absorption in a Cylindrical Quantum Dot Having Thin Falciform Cross Section

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    Energy level structure and direct light absorption in a cylindrical quantum dot (CQD), having thin falciform cross section, are studied within the framework of the adiabatic approximation. An analytical expression for the energy spectrum of the particle is obtained. For the one-dimensional “fast” subsystem, an oscillatory dependence of the wave function amplitude on the cross section parameters is revealed. For treatment of the “slow” subsystem, parabolic and modified Pöschl-Teller effective potentials are used. It is shown that the low-energy levels of the spectrum are equidistant. In the strong quantization regime, the absorption coefficient and edge frequencies are calculated. Selection rules for the corresponding quantum transitions are obtained

    Electron States and Light Absorption in Strongly Oblate and Strongly Prolate Ellipsoidal Quantum Dots in Presence of Electrical and Magnetic Fields

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    In framework of the adiabatic approximation the energy states of electron as well as direct light absorption are investigated in strongly oblate and strongly prolate ellipsoidal quantum dots (QDs) at presence of electric and magnetic fields. Analytical expressions for particle energy spectrum are obtained. The dependence of energy levels’ configuration on QD geometrical parameters and field intensities is analytically obtained. The energy levels of electrons are shown to be equidistant both for strongly oblate and prolate QDs. The effect of the external fields on direct light absorption of a QD was investigated. The dependence of the absorption edge on geometrical parameters of QDs and intensities of the electric and magnetic fields is obtained. Selection rules are obtained at presence as well as absence of external electric and magnetic fields. In particular, it is shown that the presence of the electric field cancels the quantum numbers selection rules at the field direction, whereas in radial direction the selection rules are preserved. Perspectives of practical applications for device manufacturing based on ellipsoidal quantum dots are outlined

    A Trial of Early Antiretrovirals and Isoniazid Preventive Therapy in Africa

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    BACKGROUND: In sub-Saharan Africa, the burden of human immunodeficiency virus (HIV)-associated tuberculosis is high. We conducted a trial with a 2-by-2 factorial design to assess the benefits of early antiretroviral therapy (ART), 6-month isoniazid preventive therapy (IPT), or both among HIV-infected adults with high CD4+ cell counts in Ivory Coast. METHODS: We included participants who had HIV type 1 infection and a CD4+ count of less than 800 cells per cubic millimeter and who met no criteria for starting ART according to World Health Organization (WHO) guidelines. Participants were randomly assigned to one of four treatment groups: deferred ART (ART initiation according to WHO criteria), deferred ART plus IPT, early ART (immediate ART initiation), or early ART plus IPT. The primary end point was a composite of diseases included in the case definition of the acquired immunodeficiency syndrome (AIDS), non-AIDS-defining cancer, non-AIDS-defining invasive bacterial disease, or death from any cause at 30 months. We used Cox proportional models to compare outcomes between the deferred-ART and early-ART strategies and between the IPT and no-IPT strategies. RESULTS: A total of 2056 patients (41% with a baseline CD4+ count of ≥500 cells per cubic millimeter) were followed for 4757 patient-years. A total of 204 primary end-point events were observed (3.8 events per 100 person-years; 95% confidence interval [CI], 3.3 to 4.4), including 68 in patients with a baseline CD4+ count of at least 500 cells per cubic millimeter (3.2 events per 100 person-years; 95% CI, 2.4 to 4.0). Tuberculosis and invasive bacterial diseases accounted for 42% and 27% of primary end-point events, respectively. The risk of death or severe HIV-related illness was lower with early ART than with deferred ART (adjusted hazard ratio, 0.56; 95% CI, 0.41 to 0.76; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.56; 95% CI, 0.33 to 0.94) and lower with IPT than with no IPT (adjusted hazard ratio, 0.65; 95% CI, 0.48 to 0.88; adjusted hazard ratio among patients with a baseline CD4+ count of ≥500 cells per cubic millimeter, 0.61; 95% CI, 0.36 to 1.01). The 30-month probability of grade 3 or 4 adverse events did not differ significantly among the strategies. CONCLUSIONS: In this African country, immediate ART and 6 months of IPT independently led to lower rates of severe illness than did deferred ART and no IPT, both overall and among patients with CD4+ counts of at least 500 cells per cubic millimeter. (Funded by the French National Agency for Research on AIDS and Viral Hepatitis; TEMPRANO ANRS 12136 ClinicalTrials.gov number, NCT00495651.)
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