Prediction of Anopheles minimus habitat in India—a tool for malaria management     

Aruna Srivastava Corresponding author  B. N. Nagpal  Rekha Saxena  Vas Dev  S. K. Subbarao 《International journal of geographical information science》2013,27(1):91-98

This paper reports research to predict the distribution of An. minimus, a malaria vector in forest fringe areas using GIS to support precision surveys for malaria control. Because An. minimus is a forest‐associated species, generalized thematic maps (1:6?000?000) of forest cover, soil type, altitude, rainfall and temperature were used. Digitization, overlaying, integration and analysis of thematic maps were done using Arc/Info 8.1 NT and Arc/View 3.2 (GIS, ESRI) software. GIS delineated favourable areas for An. minimus where the species is likely to be found, and precision surveys can be conducted. Precision field surveys in selected locations of favourable/non‐favourable areas were carried out. The species could be found in all locations designated as a favourable area and was absent in non‐favourable areas. In two districts, one where the species is reported to have disappeared in the early 1950s and the other where it was not reported in earlier surveys, GIS helped in precision surveys, and An. minimus was found. The technique can quickly cover vast and inaccessible areas and is easy to duplicate in other parts of the world to assist cost‐effective control of malaria. It can also delineate areas favourable for any species of flora and fauna to help precision surveys.  相似文献   

Reductive Dechlorination of PCBs Using Photocatalyzed UV Light     

Jyoti P. Ghosh  Gopal Achari  Cooper H. Langford 《洁净——土壤、空气、水》2012,40(5):455-460

Feasibility of photocatalytic dechlorination of PCB‐138 and Aroclor‐1254 using platinum loaded TiO₂ (P25) in an alkaline 2‐propanol medium has been investigated. Experiments were conducted in batch mode using a Rayonet photo‐reactor under aerated and deaerated conditions with black lamps emitting around 350 nm as light source. Two forms of platinum deposition were investigated: Photochemically loaded P25 as well as addition of potassium hexachloroplatinate into the reaction medium. Partial dechlorination of PCBs was observed after 7 h of irradiation with pure TiO₂ as catalyst when the reaction vessel was kept open to air. Complete dechlorination was observed after 5 h of irradiation in a deaerated environment. Enhanced photocatalytic efficiency was observed when platinum deposited P25 was used as catalyst, with the best result being obtained when aqueous potassium hexachloroplatinate was added into the reaction medium. Lower potassium hexachloroplatinate concentration (0.1 mM) yielded better performance.  相似文献   

Biodegradation of Acetamiprid by Isolated Bacterial Strain Rhodococcus sp. BCH2 and Toxicological Analysis of Its Metabolites in Silkworm (Bombax mori)          下载免费PDF全文

Swapnil S. Phugare  Jyoti P. Jadhav 《洁净——土壤、空气、水》2015,43(2):296-304

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Accuracy of tsunami travel‐time charts     

T. S. Murty  N. K. Saxena  Peter W. Sloss  Patricia A. Lockridge 《Marine Geodesy》2013,36(2-3):89-102

Abstract

The tsunami travel‐time charts that are presently in use by the Tsunami Warning Center were constructed originally in 1948 based on the hydrographic data available in the mid 1940s. Even the revised charts of 1971 made use of essentially the same data. It is shown here that the travel times deduced by these charts could be in error by as much as two hours in some cases. Even worse, the compiled travel times as deduced from these charts are generally greater than the observed travel times, which is a dangerous situation from a tsunami warning point of view.  相似文献   

Permian macro- and miofloral diversity,palynodating and palaeoclimate implications deduced from the coal-bearing sequences of Singrauli coalfield,Son–Mahanadi Basin,central India     

Kamal Jeet Singh  Srikanta Murthy  Anju Saxena  Husain Shabbar 《Journal of Earth System Science》2017,126(2):25

The coal-bearing sequences of Barakar and Raniganj formations exposed in Bina and Jhingurdah open-cast collieries, respectively, are analysed for their macro- and miofloral content. The sediment successions primarily comprise of sandstones, shales, claystones and coal seams. In addition to the diverse glossopterid assemblage, four palynoassemblage zones, namely Zones I and II in Bina Colliery and Zones III and IV in Jhingurdah Colliery, have also been recorded in the present study. The megafossil assemblage from the Barakar strata of Bina Colliery comprises of three genera, namely Gangamopteris, Glossopteris and cf. Noeggerathiopsis. Palynoassemblage-I is characterised by the dominance of non-striate bisaccate pollen genus Scheuringipollenites and subdominance of striate bisaccate Faunipollenites and infers these strata to be of Early Permian (Artinskian) age (Lower Barakar Formation). The palynoassemblage has also yielded a large number of naked fossil spore tetrads, which is the first record of spore tetrads from any Artinskian strata in the world and has a significant bearing on the climatic conditions. The palynoassemblage-II is characterised with the dominance of Faunipollenites over Scheuringipollenites and is indicative of Kungurian age (Upper Barakar Formation). The megafossil assemblage from the Raniganj Formation of Jhingurdah Colliery comprises of five genera with 26 species representing four orders, viz., Equisetales, Cordaitales, Cycadales and Glossopteridales. The order Glossopteridales is highly diversified with 23 taxa and the genus Glossopteris, with 22 species, dominates the flora. The mioflora of this colliery is represented by two distinct palynoassemblages. The palynoassemblage-III is correlatable with the palynoflora of Early Permian (Artinskian) Lower Barakar Formation. The assemblage suggests the continuity of older biozones into the younger ones. The palynoassemblage-IV equates the beds with composition V: Striatopodocarpites–Faunipollenites–Gondisporites assemblage zone of Tiwari and Tripathi (1992) of Late Permian (Lopingian) Raniganj Formation in Damodar Basin. The FAD’s of Alisporites, Klausipollenites, Falcisporites, Arcuatipollenites pellucidus and Playfordiaspora cancellosa palynotaxa in this assemblage enhance the end Permian level of the Jhingurdah Top seam, as these elements are the key species to mark the transition of Permian into the Lower Triassic.  相似文献   

Human health risk as a basis for prioritizing air quality monitoring stations in a megacity: a case study     

Maji  Kamal Jyoti  Dikshit  Anil Kumar  Deshpande  Ashok 《Arabian Journal of Geosciences》2017,10(18):1-20

Arabian Journal of Geosciences - The Ahnet and Tin Zaouatine terranes are located in the southern sector of the Algerian Desert and are part of the Tuareg Shield, which was built up during...  相似文献   

Iron-magnesium order-disorder in an orthopyroxene crystal from the Johnstown meteorite     

G.M. Molin  S.K. Saxena  E. Brizi 《Earth and Planetary Science Letters》1991,105(1-3)

Equilibrium reversals of Fe²⁺Mg distribution between the M1 and M2 sites of an orthopyroxene from the Johnstown meteorite were achieved at several temperatures between 700 and 1000°C. One single crystal was used for the whole thermal treatment and for collecting all the X-ray data after quenching. The intracrystalline ion exchange for the bulk chemical composition: (Mg_1.453Fe_0.441Cr_0.024Ca_0.054Mn_0.015Fe_0.005Ti_0.003Al_0.005)(Si_1.960Al_0.040)O₆ is given by: ln K_D = −3027(±39)/T(K) + 0.872(±0.013)> where K_D is the distribution coefficient for the reaction: Fe_M2²⁺ + Mg_M1 = Mg_M2 + Fe_M1²⁺.A transmission electron microscopy (TEM) study of part of the crystal showed the presence of very thin augite lamellae and Guinier-Preston zones indicating a relatively rapid cooling of the host rock at temperatures close to 1000°C. The new temperature scale yields a relatively high quenching temperature of 379 (±8)°C for the pyroxene which appears consistent with a rapid cooling (estimated few degrees per hundred years) of a magmatic cumulate excavated by an impact on its parental body.  相似文献   

Planetary phase equilibria: application to formation of Earth,Venus and Mercury     

S.K Saxena 《Geochimica et cosmochimica acta》1981,45(6):813-820

Calculations of phase equilibria in a solar mixture with variable hydrogen abundance show that the major element chemical composition of Earth and Venus can be simply explained by their formation in equilibrium at 800 and 1000 K respectively at a pressure of 1 × 10^?3 atm, provided that there is an iron loss from the region of proto-Venus relative to the solar nebula. The calculated mineralogical chemical compositions of the two planets are in excellent agreement with the available chemical and physical data. Phase equilibrium calculations at 1500 K and 1 × 10^?3 atm show that nearly 96% of the silicates and 81% of metal must have been lost from the region of proto-Mercury.  相似文献   

The MgO-Al₂O₃-SiO₂ system: free energy of pyrope and Al₂O₃-enstatite     

S.K. Saxena 《Geochimica et cosmochimica acta》1981,45(6):821-825

Using the model of fictive ideal components, Gibbs free energies of formation of pyrope and Al₂O₃-enstatite have been determined from the experimental data on coexisting garnet and orthopyroxene and orthopyroxene and spinel in the temperature range of 1200–1600 K. The negative free energies in kJ/mol are: