Quantifying Sediment Generation in Humid Tropical Regions Using Cosmogenic Nuclides - A Proof of Method

2003 ◽  
Author(s):  
Paul R. Bierman ◽  
Kyle Nichols
Keyword(s):  
Cosmogenic Nuclides ◽  
Tropical Regions

ESTIMATION OF RAIN FADE DURATIONS ON COMMUNICATION LINKS AT Ka BAND IN EQUATORIAL AND TROPICAL REGIONS

2020 ◽  
Vol 79 (2) ◽  
pp. 129-141
Author(s):  
M. E. Sanyaolu ◽  
Oluropo F. Dairo ◽  
A. A. Willoughby ◽  
L. B. Kolawole
Keyword(s):  
Ka Band ◽  
Tropical Regions ◽  
Communication Links

PERTUMBUHAN LINGKARAN POHON JATI PADA DUA SISTEM KULTUR BERBEDA DI JAWA TIMUR

2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Iriwi Louisa S. Sinon
Keyword(s):  
Tree Ring ◽  
Tectona Grandis ◽  
Annual Growth ◽  
Natural Growth ◽  
Growth Rings ◽  
Climate Effect ◽  
Tropical Regions ◽  
Annual Growth Rings ◽  
Chronological Sequence ◽  
Plantation Teak

<p><em>Study dendrochronology or tree-ring dating is defined as the study of chronological sequence of annual growth rings in trees. Teak (Tectona grandis) is one of various tree species that has been identified for the use of tree-ring studies in tropical regions. Teak is found to be suitable for dendrochronology as it is long-lived and develops defined annual growth rings. In Java, teak cans growth naturally or intensively in plantation. The two silviculture conditions will give different sensitivity on climate effect. Therefore, the effect of silviculturer will on natural teak and plantation teak in Saradan, Madiun, and East Java. As a part of the study, ten core samples from natural- growth teak were measured. The samples of growth rings is spanned from 1832 – 2004. Using the COFECHA program, the correlation of the samples (r) was found to be 0.44 point, which is satisfactory to the standard used in dendrochronology. Thus, from this study it can be concluded that natural teak could still be used in dendrochronology, although the sensitivity are not as high as plantation teak. </em></p>

Are perceived prevalences of infection also biased and how? Lessons from large epidemics of mosquito-borne diseases in tropical regions

2017 ◽  
Author(s):  
Jocelyn Raude
Keyword(s):  
Infectious Diseases ◽  
Cognitive Biases ◽  
Adult Population ◽  
Systematic Bias ◽  
Tropical Regions ◽  
Telephone Surveys ◽  
Behavioral Decision ◽  
Risk Estimates ◽  
Representative Samples ◽  
Actual Prevalence

Objectives: Although people have been repeatedly found to underestimate the frequency of risks to health from common diseases, we still do not know much about reasons for this systematic bias, which is also referred to as “primary bias” in the literature. In this study, we take advantage of a series of large epidemics of mosquito-borne diseases to examine the accuracy of judgments of risk frequencies. In this aim, we assessed the perceived versus the observed prevalence of infection by zika, chikungunya or dengue fever during these outbreaks, as well as their variations among different subpopulations and epidemiological settings.Design: We used data drawn from 4 telephone surveys, conducted between 2006 and 2016, among representative samples of the adult population in tropical regions (Reunion, Martinique, and French Guiana). The participants were asked to estimate the prevalence of these infections by using a natural frequency scale.Results: The surveys showed that (1) most people greatly overestimated the prevalence of infection by arbovirus, (2) these risk overestimations fell considerably as the actual prevalence of these diseases increased, (3) the better-educated and male participants consistently yielded less inaccurate risk estimates across epidemics, and (4) that these biases in the perception of prevalence of these infectious diseases are relatively well predicted by probability weighting function.Conclusions: These findings suggest that the cognitive biases that affect perception of prevalence of acute infectious diseases are not fundamentally different from those that characterize other types of probabilistic judgments observed in the field of behavioral decision-making. They also indicate that numeracy may play a considerable role in people’s ability to transform epidemiological observations from their social environment to more accurate risk estimates.

Comparison of sewage sludge treatment systems for regions with hot climate

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
Petia Mijaylova Nacheva ◽  
G. Moeller-Chávez ◽  
E. Ramírez-Camperos ◽  
L. Cardoso-Vigueros
Keyword(s):  
Sewage Sludge ◽  
Alkaline Treatment ◽  
Sludge Treatment ◽  
Tropical Regions ◽  
Aeration Time ◽  
Sludge Stabilization ◽  
Hot Climate ◽  
Aerobic Stabilization ◽  
Sewage Sludge Treatment ◽  
High Pathogenic

The tropical regions have specific problems associated with high pathogenic density in the sewage sludge. The aim of this study was to select an adequate sludge stabilization and valorization system comparing the performance of four technologies: anaerobic stabilization without heating, aerobic stabilization, alkaline treatment with lime and aerobic composting. The study was performed in a pilot plant which was built and operated during six months. The main problem for the beneficial use of the sludge was its pathogenicity. All the systems allowed obtaining stabilized products which met the bacteriological criteria for some kind of use. The compost and the alkalinized sludge were bacteriologically safe for use without restrictions in accordance with the Mexican regulations. The accomplishment of the parasitological criteria for use was however impossible with the anaerobic and with the aerobic systems. The compost obtained at 55-60°C with 25d aeration time and the alkaline sludge fulfill the criteria established by for forest and agriculture use and for soil conditioning. The composting could reach the requirements for unrestricted use when operated at temperatures 65-70°C during 45 days which makes it the most adequate sludge treatment system for hot climate regions.

Antiulcer and Antioxidant Activity of a Lectin from Mucuna pruriens Seeds on Ethanol- induced Gastropathy: Involvement of Alpha-2 Adrenoceptors and Prostaglandins

2019 ◽  
Vol 25 (12) ◽  
pp. 1430-1439 ◽  
Author(s):  
Isabela Ribeiro Pinto ◽  
Hellíada V. Chaves ◽  
Auriana S. Vasconcelos ◽  
Francisca Clea F de Sousa ◽  
Tatiane Santi-Gadelha ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Acute Toxicity ◽  
Antioxidant Activities ◽  
Mucuna Pruriens ◽  
Toxicity Tests ◽  
Sod Activity ◽  
Tropical Regions ◽  
Mediated Effects ◽  
Menstruation Disorders ◽  
Therapeutic Tools

Ethnopharmacological Relevance:Mucuna pruriens (Mp) belongs to Leguminosae family, it is native of tropical regions and used to treat several maladies such as urinary, neurological, and menstruation disorders, constipation, edema, fever, tuberculosis, ulcers, diabetes, arthritis, dysentery, and cardiovascular diseases. Mp seeds are rich in bioactive compounds, for instance, lectins, a heterogeneous group of proteins and glycoproteins with a potential role as therapeutic tools for several conditions, including gastric disorders. This study investigated the acute toxicity, gastroprotective, and antioxidant activities of a lectin from Mucuna pruriens seeds (MpLec) on ethanol-induced gastropathy model in mice.Materials & Methods:Mice received MpLec (5 or 10 mg/kg; i.v.) and were observed for acute toxicity signs; in another experimental series, mice were pre-treated with MpLec (0.001; 0.01 or 0.1 mg/kg, i.v.), ranitidine (80 mg/kg, p.o.), or saline (0.3 mL/30g, i.v.) before ethanol 99.9% (0.2 mL/animal, p.o.), and euthanized 30 min after ethanol challenge. Macroscopic and microscopic gastric aspects, biochemical parameters (tissue hemoglobin levels, iron-induced lipid peroxidation, GSH content, SOD activity, and gastric mucosal PGE2) were measured. Additionally, pharmacological tools (yohimbine, indomethacin, naloxone, L-NAME) were opportunely used to clarify MpLec gastroprotective mechanisms of action.Results:No toxicity signs nor death were observed at acute toxicity tests. MpLec reduced ethanol-induced gastric damage, edema, and hemorrhagic patches formation, as well as decreased lipid peroxidation, SOD activity, and increased GSH content. Yohimbine and indomethacin prevented MpLec effects, suggesting the involvement of alpha-2 adrenoceptors and prostaglandins in the MpLec-mediated effects.Conclusion:MpLec does not present toxicity signs and shows gastroprotective and antioxidant activities via alpha-2 adrenoceptors and prostaglandins in the ethanol-induced gastropathy model.

Momordica balsamina L.: An Appraisal on Morphology, Ecological Diversity, Phytochemistry, Pharmacological and Biotechnological Applications

2020 ◽  
Vol 06 ◽  
Author(s):  
Saheed Sabiu ◽  
Christiana Eleojo Aruwa ◽  
Viresh Mohanlall ◽  
Himansu Baijnath
Keyword(s):  
Relevant Information ◽  
Perennial Herb ◽  
Biotechnological Applications ◽  
Tropical Regions ◽  
Toxicological Data ◽  
Human Disorders ◽  
Potential Applications ◽  
Baseline Information ◽  
The Caribbean ◽  
Bioactive Agents

Background: Momordica balsamina L. is a monoecious climbing vine and perennial herb native to the tropical regions of Asia, Arabia and the Caribbean, and with prominent presence in Nigeria, Botswana, Namibia, Swaziland and Southern African provinces. While evidence of its anecdotal usage as medicine exist, scientific reports complementing the claims are still emerging or at their infancy. Objective: This review appraised the morphology, therapeutic and biotechnological significance of M. balsamina. Method: Online resources such as Google Scholar, PubMed, ScienceDirect and MeSH were utilized for literature search and included relevant information from inception till May 2020 to streamline sought outcomes for in-depth discussion. Results: The data gathered and considered worthy of inclusion in this study revealed that M. balsamina is rich in phytonutrients of medicinal significance with cucurbitane-type triterpenoids, balsamin and momordins well characterized and fully elucidated. These compounds and other novel bioactive agents in M. balsamina have found remarkable pharmacological relevance and could further be harnessed for use against several debilitating human disorders. Conclusion: The potential applications of M. balsamina as nutraceutical and pharmaceutical agent should not be undermined. Also, with the inadequate toxicological data on this wild species, its consumption should be with caution and translational studies that could advance scientific knowledge and aid better understanding of both its pharmacokinetics and pharmacodynamics without sidelining its potent biotechnological applications are highly encouraged. It is hoped that this paper will provide baseline information that could serve as a guide and inspiration for further studies on the prospects of M. balsamina.

REWORKED CLAY AS A GEOCHEMICAL EXPLORATION TOOL FOR MAGMATIC-HYDROTHERMAL ORE DEPOSITS IN TROPICAL REGIONS

2018 ◽  
Author(s):  
Marco Perez ◽  
◽  
David J. Wronkiewicz ◽  
Marek Locmelis ◽  
Eric Bohannan
Keyword(s):  
Ore Deposits ◽  
Geochemical Exploration ◽  
Tropical Regions ◽  
Exploration Tool ◽  
Hydrothermal Ore Deposits

In Situ-Produced Cosmogenic Nuclides and Quantification of Geological Processes

2006 ◽  
Author(s):  
Ana María Alonso-Zarza ◽  
Lawrence H. Tanner
Keyword(s):  
Cosmogenic Nuclides ◽  
Geological Processes
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