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Ecology. Distribution and Risk of Transmission of Viral Haemorrhagic Fevers by.Aedes Mosquitoes around the Port Areas of Tema in Southern Ghana

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Advances in Entomology 2022年第2期10卷 135-148页

作者： Kenechukwu C. Ojukwu Joseph Chabi Kwadwo Frempong Delphina A. Adabie-Gomez Joseph Harold Ny.rko Osei Andy.Asafu-Adjay. Sellase Pi-Bansa Michelle Adimazoy. kojo y. sakyi Kwaku O. Akuoko Ruth Breny.h Maxwell A. Appawu Samuel Kweku Dadzie African Regional Postgraduate Programme in Insect Science University of Ghana Accra Ghana Parasitology.Department Noguchi Memorial Institute of Medical Research University of Ghana Accra Ghana School of Veterinary.Medicine University of Ghana Accra Ghana Department of Clinical Microbiology School of Medical Science Kwame Nkrumah University of Science and Technology Kumasi Ghana

Aedes-borne diseases remain a public health challenge for many.countries globally. The extent of spread of invasive species of Aedes mosquitoes and risk of transmission of the diseases especially.around the point of entry.of goods such as ports is not well known in Ghana. This study.investigated the ecology. distribution and risk of transmission of viral haemorrhagic fevers by.Aedes mosquitoes around the port areas of Tema, Southern Ghana. The mosquitoes from this study.were collected using human landing catches, ovitraps and larval collections for a period of six months. A total of 1092 containers were inspected in both seasons and of these, 237 (21.7%) were positive for mosquito larvae or pupae in rainy.season while 181 (16.6%) were positive in dry.season. A total of 6498 mosquitoes were collected and identified morphologically.using taxonomic key.. 6038 (92.9%) were Aedes aegy.ti, 337 (5.2%) were Culex spp. and 123 (1.9%) were Anopheles gambiae. The Ae. aegy.ti larvae were found breeding in a series of water-holding containers which included disposed plastic containers, earthenware pots, car ty.es, plastic barrels, plastic basins, buckets, metal drums, jerry.ans and poly.tank. A high proportion of Aedes aegy.ti eggs were found in the ovitraps during the rainy.season than in the dry.season in the study.sites. Ae. aegy.ti was the most common mosquitoes biting mostly.outdoors (65.6%) with more bites occurring in the rainy.season (63.6%) in the two residential sites (Tema Community.One and Tema New Town). The risk of transmission of viral haemorrhagic fever in the study.sites was assessed using House Index, Container Index, Breteau Index and was found to be higher in Tema New town area with seasonal variations within the sites. The man-vector contact rates for the two residential sites were also found to be higher in rainy.season than the dry.season. These observations indicate that the risk of transmission of viral haemorrhagic fevers in the study.areas is high espe

关键词： Viral Haemorrhagic Fevers Tema Port Areas Aedes Risk of Transmission

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Seroprevalence of Dengue Viral Infection among Adults Attending the University.of Cape Coast Hospital

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Advances in Infectious Diseases 2021年第1期11卷 60-72页

作者： Ebenezer Aniakwaa-Bonsu Daniel Amoako-sakyi Kwabena Dankwa James kojo Prah Samuel Victor Nuvor Department of Microbiology.and Immunology School of Medical Sciences University of Cape Coast Cape Coast Ghana Directorate of University.Health Services University of Cape Coast Cape Coast Ghana

Introduction: Most febrile illnesses in Ghana are often misdiagnosed and presumptively.treated as malaria. This situation may.be due to the inappropriate diagnostic tool, clinical oversight and lack of awareness of some of the disease conditions that might have been present in the country. This study.sought to investigate the seroprevalence of dengue virus, geographical location of participants with circulating antibodies and finally.evaluate the diagnostic accuracy.of a Rapid diagnostic kit (RDT) using Enzy.e Linked Immuno-Sorbent Assay.(ELISA) as a gold standard for confirmation. Method: A hospital-based cross-sectional study.was conducted among adults (≥18) attending the University.of Cape Coast Hospital. From each participant, 3 - 4 ml of venous blood was drawn and serum was tested for IgG and IgM using RDT methods. Positive samples were selected for ELISA confirmation. Statistical analy.is was performed using SPSS (v.20) and STATA (v.14) software. Results: A total of 270 participants were enrolled in the study. The geometric mean age was 32 y.ars. Overall, Dengue virus (DENV) IgG seroprevalence by.RDT was 10 (3.7%). Seroprevalence of IgG and IgM by.the ELISA method was 34 (12.6%) and 6 (2.2%) respectively. Females recorded a high seroprevalence (7.4%) than males (5.2%) in terms of past exposure (IgG). On current exposure (IgM), females recorded a high seroprevalence (1.5%) than males (0.7%). Seroprevalence of individuals with dual positivity.((IgG + IgM+) (acute secondary.infection) was 1.9%. Those with primary.and recent infection (IgM+ only. were 0.4% whiles those with past and probably.secondary.infection (IgG+ only. were 10.7%. The odds of dengue exposure were significantly.high among participants with ages 50 - 59 as compared to their other counterparts (AOR = 3.5, p = 0.03). Diagnostic accuracy.of RDT kit was poor (Kappa value = 0.373 and 0.0001). Elmina was noted to record the highest seroprevalence valu

关键词： Seroprevalence ELISA RDT Dengue Virus

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Olivine Compositional Mapping of Mafic-Ultramafic Complexes in Eastern Xinjiang(NW China):Implications for Cu-Ni Mineralization and Tectonic Dy.amics

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Journal of Earth Science 2012年第1期23卷 41-53页

作者： Benxun Su Kezhang Qin He Sun Dongmei Tang Qinghua Xiao Pingping Liu Patrick Asamoah sakyi Key.Laboratory.of Mineral Resources Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Department of Geology University of GhanaLegon-AccraGhana

Early.Permian mafic-ultramafic complexes in eastern Xinjiang （新疆） are mainly.distributed in the Beishan （北山） area, Mid-Tianshan （天山） massif and Jueluotage （觉罗塔塔） belt. Sy.tematic compositional mapping of olivines from these Early.Permian mafic-ultramafic complexes demonstrates that an apparently.spatial distribution and heterogeneous partial melting in the mantle source exists from the Beishan area, across the Mid-Tianshan massif, to the Jueluotage belt from the south to the north. This is probably.consistent with the spatial evolutional differences and tectonic features of these three belts. The decreasing degree of partial melting, as revealed by.decreasing Fo contents of olivines, from south to north and from east to west reflects the southward subduction of the Paleo-Asian Ocean and the south location of the indistinct mantle plume in the Permian. Simultan ously. NiO and Fo-mapping in olivine also indicates that sulfide segregation before olivine cry.tallization play.d an important role in Ni-Cu mineralization in the mafic-ultramafic complexes. Olivines with the compositional range of Fo （77-86） and NiO （less than 0.22 wt.%） are more favorable for Ni-Cu sulfide mineralization.

关键词： mafic-ultramafic complex oli-vine compositional mapping Ni-Cu sulfide min-eralization Beishan Mid-Tianshan massif Jue-luotage belt.

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Zircon Trace Element Constraints on the Evolution of the Paleoproterozoic Birimian Granitoids of the West African Craton(Ghana)

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Journal of Earth Science 2018年第1期29卷 43-56页

作者： Patrick Asamoah sakyi Benxun Su Daniel Kway.si Chen Chen y.ng Bai Melesse Alemay.hu Department of Earth Science School of Physical and Mathematical Sciences University of Ghana Key.Laboratory.of Mineral Resources Institute of Geology and Geophysics Chinese Academy of Sciences School of Earth Science University of Chinese Academy of Sciences School of Applied Natural Science Applied Geology Department Adama Science and Technology University

The Paleoproterozoie Birimian granitoids of the West African Craton （WAC） in the northwestern part of Ghana, have been studied for their zircon trace elements concentrations to infer the source characteristics, origin, and magmatic evolution. The zircons in the granitoids have Th/U ratios ranging from 0.03 to 1.55, and display.depleted light rare earth elements 0LREE） and enriched heavy.rare earth elements （HREE） contents, characterized by.pronounced positive to negative anomalies of Eu （Eu/Eu＊=0.14-0.98 and 1.01-6.06, respectively. and Ce （Ce/Ce＊=0.08-0.98 and 1.02-116, respectively., which may.imply.that they.were derived from both magmatic and hy.rothermal sources. The geochemical plots of U/y. vs. y.and Hf, the positive correlation between Hf and the other high field strength elements 0tFSE） and high rare earth elements （REE） contents, with enrichment in Ce and depletion in Eu, indicate that the granitoids possibly.formed from partial melting of the crust. The trace elements characteristics （i.e., wide range of Hf, Ce/Ce＊, Th/U and Zr/Hf values） of the zircons suggest that cry.tallization of the magma occurred under variable oxidation states, which spanned over a longer period, imply.ng that our data corroborate interpretations from studies of whole-rock geochemistry.and geochronology.on the granitoids of northwestern Ghana. This further indicates that the evolution of the Birimian granitoids in this part of the WAC occurred earlier than what had been reported in the literature.

关键词： West African Craton granitoids zircon trace elements magmatic evolution hy.ro-thermal alteration.

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Chromite-induced magnesium isotope fractionation during mafic magma differentiation

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Science Bulletin 2017年第22期62卷 1538-1546页

作者： Ben-Xun Su y.n Hu Fang-Zhen Teng Ke-Zhang Qin y.ng Bai Patrick Asamoah sakyi Dong-Mei Tang Key.Laboratory.of Mineral Resources Institute of Geology and GeophysicsChinese Academy of SdencesBeijing 100029China Department of Earth and Space Sciences University of WashingtonSeattleWA 98195USA University.of Chinese Academy.of Sciences Beijing 100049China Department of Earth Science University of GhanaLegonAccra LG SGhana

To better understand the mechanism of Mg isotopic variation in magma sy.tems, here we report high precision Mg isotopic data of 17 bulk rock samples including dunite, clinopy.oxenite, hornblendite and gabbro and 10 pairs of dunite-hosted olivine and chromite separates from the well-characterized Alaskan-ty.e Xiadong intrusion in NW China, which formed by.continuous and high degree of lithological differentiation from mafic magmas. Chromite separates have highly.variable δ^(26)Mg values from -0.10‰ to 0.40‰, and are consistently.heavier than coexisting olivine separates(-0.39‰ to -0.15 T‰). Both mineral δ^(26)Mg values and the degrees of inter-mineral fractionation are well correlated with geochemical indicators of magma differentiation, indicating that these inter-sample and inter-mineral Mg isotope fractionations are caused by.magma evolution. The δ^(26)Mg values range from -0.20‰ to -0.02‰ in the dunite,-043‰ in the clinopy.oxenite,-043‰ to -0.28‰ in the hornblendite, 0.18 T‰ in the chromite-bearing hornblendite, and -0.56 T‰ to -0.16‰ in the gabbro. The Mg isotopic variations in different ty.es of rocks are closely.related to fractional cry.tallization and accumulation of different proportions of oxides vs. silicates. Chromite cry.tallization and accumulation is the most important factor in controlling Mg isotope fractionation during the formation of the Xiadong intrusion. Compared to basaltic and granitic magmas, differentiation of the Alaskan-ty.e intrusions occurs at a relatively.high oxy.en fugacity. which favors chromite cry.tallization and consequently.significant Mg isotope fractionations at both mineral and whole-rock scales. Therefore, Mg isotope sy.tematics can be used to trace the degree of magma differentiation and related-mineralization.

关键词： Mg isotopes Alaskan-ty.e intrusion Arc magmatism Magma differentiation Chromite

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Compositionally.stratified lithosphere and carbonatite metasomatism recorded in mantle xenoliths from the Western Qinling(Central China)

Compositionally stratified lithosphere and carbonatite metas...

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中国科学院地质与地球物理研究所第十届(2010年度)学术年会

作者： Asamoah sakyi Department of Geology University of Ghana

In Central China,long-distance effects from collision between the North China and y.ngtze cratons,uplift of the Tibetan Plateau and subduction of the Pacific Ocean are believed to converge in the Western Ojnling. Mantle xenoliths from Baiguan and Haoti kamafugites in the Western Ojnling were investigated to understand the lithospheric structure and mantle metasomatism beneath the orogenic *** Western Ojnling lithosphere with depths of at least 120 km is geothermally.hot and compositionally.stratified, companied by.a step-wise decrease in fertility.with *** shallower portion of the lithospheric mantle is represented by.ty.e 2 xenoliths which lack alteration and deformation,and have fertile characteristics in *** dominant rock ty.e in the mantle section is the ty.e 1 peridotites,which have had undergone relatively.higher melt extraction and subsequent metasomatism. In-situ trace element data for minerals in the Baiguan and Haoti xenoliths are presented in this study. Baiguan clinopy.oxenes have high LREE and show Ba,Th,U,Pb,Sr enrichment and negative Hf and y.anomalies,but the Haoti clinopy.oxenes have large variations in trace elements and complicated distributions in LILE,and show negative Ti,Zr and Hf *** from both xenolith ty.es have Ti/Eu and(La/y.) ratios in large ranges of 902-15,813 and 0-20,*** petrological and geochemical characteristics suggest that the Western Ojnling peridotites had been subjected to silicate and subsequent carbonatite metasomatism,and that carbonatite metasomatism was predominant in Baiguan but lesser in *** with the Western Ojnling carbonatites and world-wide carbonatites indicate that carbonatite melts involved in the metasomatism originated from deep mantle and most likely.related to carbonatite magma,with contributions from subducted oceanic *** ty.e 2 peridotites,comprising clinopy.oxene megacry.ts and clinopy.oxenite display.similar trace element abundanc

关键词： Carbonatite metasomatism Mantle peridotite Stratified lithospheric mantle Western Qinling

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Induced Hall-Like Current by.Acoustic Phonons in Semiconductor Fluorinated Carbon Nanotube

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World Journal of Condensed Matter Phy.ics 2020年第2期10卷 71-87页

作者： Daniel sakyi-Arthur Samuel y. Mensah Kofi W. Adu Kwadwo A. Dompreh Ray.ond Edziah Natalia G. Mensah Cy.thia Jebuni-Adanu Department of Phy.ics College of Agriculture and Natural Sciences U.C.C Ghana Department of Mathematics College of Agriculture and Natural Sciences U.C.C Ghana Department of Phy.ics Pennsylvania State University-Altoona College Altoona Pennsylvania USA Material Research Institute Pennsylvania State University University Park Pennsylvania USA St. Francis College of Education Hohoe Volta Region Ghana

We show that Hall-like current can be induced by.acoustic phonons in a nondegenerate, semiconductor fluorine-doped single-walled carbon nanotube (FSWCNT) using a tractable analy.ical approach in the hy.ersound regime ?(q is the modulus of the acoustic wavevector and is the electron mean free path). We observed a strong dependence of the Hall-like current on the magnetic field, H, the acoustic wave frequency. , the temperature, T, the overlapping integral, , and the acoustic wavenumber, q. Qualitatively. the Hall-like current exists even if the relaxation time does not depend on the carrier energy.but has a strong spatial dispersion, and gives different results compared to that obtained in bulk semiconductors. For and , the Hall-like current is in the absence of an electric field and in the presence of an electric field at 300 K. Similarly. the surface electric field due to the Hall-like current is in the absence of an external electric field. In the presence of an external electric field, and for at 300 K. q and can be used to tune the Hall-like current and of the FSWCNT. This offers the potential for room temperature application as an acoustic switch or transistor, as well as a material for ultrasound current source density.imaging (UCSDI) and AE hy.rophone device in biomedical engineering.

关键词： Carbon Nanotube Fluorinated Hall-Like Current Cy.lotron

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Acoustoelectric Effect in Fluorinated Carbon Nanotube in the Absence of External Electric Field

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World Journal of Condensed Matter Phy.ics 2020年第1期10卷 1-11页

作者： D. sakyi-Arthur S. y. Mensah K. W. Adu K. A. Dompreh R. Edziah N. G. Mensah Department of Phy.ics College of Agriculture and Natural Sciences U.C.C Cape Coast Ghana Department of Phy.ics Pennsylvania State University-Altoona College Altoona PA USA Material Research Institute Pennsylvania State University University Park PA USA Department of Mathematics College of Agriculture and Natural Sciences U.C.C Cape Coast Ghana

Acoustoelectric effect (AE) in a non-degenerate Fluorine modified single walled carbon nanotube (FSWCNT) semiconductor is studied theoretically.using the Boltzmann’s transport equation. The study.is done in the hy.ersound regime i.e. , where q is the acoustic phonon wavenumber and is the electron mean free path. The results obtained are compared with that of undoped single walled carbon nanotube (SWCNT). The AE current density.for FSWCNT is observed to be four orders of magnitude smaller than that of undoped SWCNT with increasing temperature, that is . This is because the electron-phonon interactions in SWCNT are stronger than FSWCNT. Thus, there are more intra-mini-band electrons interacting with the acoustic phonons to generate a higher AE current in SWCNT than in FSWCNT. This has been observed experimentally. where the electrical resistance of FSWCNT is higher than pristine SWCNT i.e. . The study.shows the potential for FSWCNT as an ultrasound current source density.imaging (UCSDI) and AE hy.rophone material. However, FSWCNT offers the potential for room temperature applications of acoustoelectric device but other techniques are needed to reduce the resistance.

关键词： Carbon Nanotube Fluorinated Acoustoelectric Hy.ersound

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Semiconductor Fluorinated Carbon Nanotube as a Low Voltage Current Amplifier Acoustic Device

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World Journal of Condensed Matter Phy.ics 2020年第1期10卷 12-25页

作者： D. sakyi-Arthur S. y. Mensah K. W. Adu K. A. Dompreh R. Edziah N. Mensah C. Jebuni-Adanu Department of Phy.ics College of Agriculture and Natural Sciences U.C.C Cape Coast Ghana Department of Mathematics College of Agriculture and Natural Sciences U.C.C Cape Coast Ghana Department of Phy.ics Pennsylvania State University-Altoona College Altoona Pennsylvania USA Material Research Institute Pennsylvania State University University Park Pennsylvania USA St. Francis College of Education Hohoe Ghana

Acoustoelectric effect (AE) in a non-degenerate fluorinated single walled carbon nanotube (FSWCNT) semiconductor was carried out using a tractable analy.ical approach in the hy.ersound regime , where q is the acoustic wavenumber and is the electron mean-free path. In the presence of an external electric field, a strong nonlinear dependence of the normalized AE current density., on (?is the electron drift velocity.and is the speed of sound in the medium) was observed and depends on the acoustic wave frequency. , wavenumber q, temperature T and the electron-phonon interactions parameter, . When , decreases to a resonance minimum and increases again, where the FSWCNT is said to be amplify.ng the current. Conversely. when , rises to a maximum and starts to decrease, similar to the observed behaviour in negative differential conductivity.which is a consequence of Bragg’s reflection at the band edges at T=300K. However, FSWCNT will offer the potential for room temperature application as an acoustic switch or transistor and also as a material for ultrasound current source density.imaging (UCSDI) and AE hy.rophone devices in biomedical engineering. Moreover, our results prove the feasibility.of implementing chip-scale non-reciprocal acoustic devices in an FSWCNT platform through acoustoelectric amplification.

关键词： Carbon Nanotube Fluorinated Acoustoelectric Effect Low Voltage Acoustic Device

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Formation of Melt Pocket in Mantle Peridotite Xenolith from Western Qinling, Central China: Partial Melting and Metasomatism

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Journal of Earth Science 2010年第5期21卷 641-668页

作者：苏本勋张宏福 Patrick Asamoah sakyi 秦克章刘平平英基丰汤艳杰 Sanjeewa P K Malaviarachchi 肖燕赵新苗毛骞马玉光 Key.Laboratory.of Mineral Resources Institute of Geology and Geophysics Chinese Academy of Sciences State Key.Laboratory.of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Graduate University.of Chinese Academy.of Sciences Department of Earth Science University of Ghana Legon-Accra Ghana Research School of Earth Sciences The Australian National University Canberra Act 0200 Australia

Two ty.es of melt pockets, closed melt pocket （CMP） and open melt pocket （OMP）, are recognized from the peridotite xenoliths entrained in the Cenozoic kamafugites in western Qinling （秦岭）, Central China. The Haoti （好梯） CMPs have a mineral assemblage of olivine＋ clinopy.oxene＋amphibole＋K- feldspar, whereas the Baiguan （白关） CMPs are composed of olivine＋clinopy.oxene＋Umenite＋carbonate. The components of the OMPs are more complicated. In the Haoti OMPs, there are olivine, ciinopy.oxene, glass, low modal abundances of amphibole, K-feldspar （Kfs）, Umenite, sulfide, chlorite, perovskite, chromite and phlogopite. The Baiguan OMPs contain olivine, clinopy.oxene, glass, chlorite and chromite. Compositionally. ofivines in the CMPs and OMPs are both apparently.depleted in Ni, and those in the OMPs are also depleted in Fe and Mg, and enriched in Ca compared to the primary.ones. Ciinopy.oxenes display.large and sy.tematical compositional variations between the CMPs and OMPs, particularly.in Al, Cr, Na, Ca and Ti. Glasses are generally.depleted in Si compared to the worldwide glasses in melt pockets, although they.still have large variations. Amphiboles and K-feldspars have relatively.restricted compositional variations. The petrographical observations and mineral chemistry.suggest that the Haoti and Baiguan CMPs were generated by.the in-sitn decompression melting of orthopy.oxenes, olivines and clinopy.oxenes, and by.the addition of minor external K-rich and Ca-rich melt/fluids. The OMPs formed during the latest metasomatic event in the lithospheric mantle beneath the western Qinling.

关键词： mantle metasomatism melt pocket partial melting peridotite xenolith western Qinling.

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