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Sample records for bioko equatorial guinea

  1. Checklist of the Caesalpinioideae (Leguminosae) of Equatorial Guinea (Annobón, Bioko and Río Muni)

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    Estrella, Manuel de la; Aedo, Carlos; Cabezas, Francisco J.; Velayos, Mauricio

    2006-01-01

    This study provides a checklist of the Caesalpinioideae (Leguminosae) present in Equatorial Guinea, comprising 52 genera and 124 taxa. Seven species are known from Annobón, 33 from Bioko and 109 from Río Muni. The best represented genus is Senna with eight species. In addition, bibliographic references for Caesalpinioideae (Leguminosae) from Equatorial Guinea have been gathered and checked. Fourteen species are included based on literature records, because their distribution...

  2. Serological markers suggest heterogeneity of effectiveness of malaria control interventions on Bioko Island, equatorial Guinea.

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    Jackie Cook

    Full Text Available BACKGROUND: In order to control and eliminate malaria, areas of on-going transmission need to be identified and targeted for malaria control interventions. Immediately following intense interventions, malaria transmission can become more heterogeneous if interventions are more successful in some areas than others. Bioko Island, Equatorial Guinea, has been subject to comprehensive malaria control interventions since 2004. This has resulted in substantial reductions in the parasite burden, although this drop has not been uniform across the island. METHODS/PRINCIPAL FINDINGS: In 2008, filter paper blood samples were collected from 7387 people in a cross-sectional study incorporating 18 sentinel sites across Bioko, Equatorial Guinea. Antibodies were measured to P. falciparum Apical Membrane Antigen-1 (AMA-1 by Enzyme Linked Immunosorbent Assay (ELISA. Age-specific seropositivity rates were used to estimate seroconversion rates (SCR. Analysis indicated there had been at least a 60% decline in SCR in four out of five regions on the island. Changes in SCR showed a high degree of congruence with changes in parasite rate (PR and with regional reductions in all cause child mortality. The mean age adjusted concentration of anti-AMA-1 antibodies was mapped to identify areas where individual antibody responses were higher than expected. This approach confirmed the North West of the island as a major focus of continuing infection and an area where control interventions need to be concentrated or re-evaluated. CONCLUSION/INTERPRETATION: Both SCR and PR revealed heterogeneity in malaria transmission and demonstrated the variable effectiveness of malaria control measures. This work confirms the utility of serological analysis as an adjunct measure for monitoring transmission. Age-specific seroprevalence based evidence of changes in transmission over time will be of particular value when no baseline data are available. Importantly, SCR data provide additional

  3. Light traps fail to estimate reliable malaria mosquito biting rates on Bioko Island, Equatorial Guinea

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    Overgaard Hans J

    2012-02-01

    Full Text Available Abstract Background The human biting rate (HBR, an important parameter for assessing malaria transmission and evaluating vector control interventions, is commonly estimated by human landing collections (HLC. Although intense efforts have been made to find alternative non-exposure mosquito collection methods, HLC remains the standard for providing reliable and consistent HBRs. The aim of this study was to assess the relationship between human landing and light trap collections (LTC, in an attempt to estimate operationally feasible conversion factors between the two. The study was conducted as part of the operational research component of the Bioko Island Malaria Control Project (BIMCP, Equatorial Guinea. Methods Malaria mosquitoes were collected indoors and outdoors by HLCs and LTCs in three villages on Bioko Island, Equatorial Guinea during five bimonthly collections in 2009. Indoor light traps were suspended adjacent to occupied long-lasting, insecticide-treated bed nets. Outdoor light traps were placed close to the outer wall under the roof of the collection house. Collected specimens were subjected to DNA extraction and diagnostic PCR to identify species within the Anopheles gambiae complex. Data were analysed by simple regression of log-transformed values and by Bayesian regression analysis. Results There was a poor correlation between the two collection methods. Results varied by location, venue, month, house, but also by the statistical method used. The more robust Bayesian analyses indicated non-linear relationships and relative sampling efficiencies being density dependent for the indoor collections, implying that straight-forward and simple conversion factors could not be calculated for any of the locations. Outdoor LTC:HLC relationships were weak, but could be estimated at 0.10 and 0.07 for each of two locations. Conclusions Light trap collections in combination with bed nets are not recommended as a reliable method to assess human

  4. Evidence for Suppression of Onchocerciasis Transmission in Bioko Island, Equatorial Guinea.

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    Moya, Laura; Herrador, Zaida; Ta-Tang, Thuy Huong; Rubio, Jose Miguel; Perteguer, Maria Jesús; Hernandez-González, Ana; García, Belén; Nguema, Rufino; Nguema, Justino; Ncogo, Policarpo; Garate, Teresa; Benito, Agustín; Sima, Anacleto; Aparicio, Pilar

    2016-07-01

    Onchocerciasis or "river blindness" is a chronic parasitic neglected tropical disease which is endemic both in mainland and insular Equatorial Guinea. We aim to estimate the current epidemiological situation of onchocerciasis in Bioko Island after vector elimination in 2005 and more than sixteen years of Community Directed Treatment with Ivermectin (CDTI) by using molecular and serological approaches for onchocerciasis diagnosis. A community-based cross-sectional study was carried out in Bioko Island from mid-January to mid-February 2014. A total of 544 study participants were recruited. A complete dermatological examination was performed and three skin snips were performed in every participant for parasitological and molecular assessments. Blood spots were also taken for determination of Ov16 IgG4 antibodies trough an "in-house" ELISA assay. Overall, we found 15 out of 522 individuals suffering any onchocerciasis specific cutaneous lesions and 16 out of 528 (3.0%) with onchocercal nodules in the skin. Nodules were significantly associated with age, being more common in subjects older than 10 years than in younger people (3.9% vs. 0%, p = 0.029). Regarding the onchocerciasis laboratory assessment, no positive parasitological test for microfilaria detection was found in the skin snips. The calculated seroprevalence through IgG4 serology was 7.9%. No children less than 10 years old were found to be positive for this test. Only one case was positive for Onchocerca volvulus (O. volvulus) after skin PCR. The present study points out that the on-going mass ivermectin treatment has been effective in reducing the prevalence of onchocerciasis and corroborates the interruption of transmission in Bioko Island. To our knowledge, this is the first time that accurate information through molecular and serological techniques is generated to estimate the onchocerciasis prevalence in this zone. Sustained support from the national program and appropriate communication and health

  5. Evidence for Suppression of Onchocerciasis Transmission in Bioko Island, Equatorial Guinea.

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    Laura Moya

    2016-07-01

    Full Text Available Onchocerciasis or "river blindness" is a chronic parasitic neglected tropical disease which is endemic both in mainland and insular Equatorial Guinea. We aim to estimate the current epidemiological situation of onchocerciasis in Bioko Island after vector elimination in 2005 and more than sixteen years of Community Directed Treatment with Ivermectin (CDTI by using molecular and serological approaches for onchocerciasis diagnosis. A community-based cross-sectional study was carried out in Bioko Island from mid-January to mid-February 2014. A total of 544 study participants were recruited. A complete dermatological examination was performed and three skin snips were performed in every participant for parasitological and molecular assessments. Blood spots were also taken for determination of Ov16 IgG4 antibodies trough an "in-house" ELISA assay. Overall, we found 15 out of 522 individuals suffering any onchocerciasis specific cutaneous lesions and 16 out of 528 (3.0% with onchocercal nodules in the skin. Nodules were significantly associated with age, being more common in subjects older than 10 years than in younger people (3.9% vs. 0%, p = 0.029. Regarding the onchocerciasis laboratory assessment, no positive parasitological test for microfilaria detection was found in the skin snips. The calculated seroprevalence through IgG4 serology was 7.9%. No children less than 10 years old were found to be positive for this test. Only one case was positive for Onchocerca volvulus (O. volvulus after skin PCR. The present study points out that the on-going mass ivermectin treatment has been effective in reducing the prevalence of onchocerciasis and corroborates the interruption of transmission in Bioko Island. To our knowledge, this is the first time that accurate information through molecular and serological techniques is generated to estimate the onchocerciasis prevalence in this zone. Sustained support from the national program and appropriate communication

  6. Impact of different strategies to control Plasmodium infection and anaemia on the island of Bioko (Equatorial Guinea

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    Roche Jesús

    2006-02-01

    Full Text Available Abstract Background On the island of Bioko (Equatorial Guinea, insecticide-treated nets (ITNs have been the main tool used to control malaria over the last 13 years. In 2004, started an indoor residual spraying (IRS campaign to control malaria. The purpose of this study is to asses the impact of the two control strategies on the island of Bioko (Equatorial Guinea, with regards to Plasmodium infection and anaemia in the children under five years of age. Methods Two transversal studies, the first one prior to the start of the IRS campaign and the second one year later. Sampling was carried out by stratified clusters. Malaria infection was measured by means of thick and thin film, and the packed cell volume (PCV percentage. Data related to ITN use and information regarding IRS were collected. The Pearson's chi-square and logistic regression statistical tests were used to calculate odds ratios (OR Results In the first survey, 168 children were sampled and 433 children in the second one. The prevalence of infection was 40% in 2004, and significantly lower at 21.7% in 2005. PCV was 41% and 39%, respectively. 58% of the children surveyed in 2004 and 44.3% in 2005 had slept under an ITN. 78% of the dwellings studied in 2005 had been sprayed. In the 2005 survey, sleeping without a mosquito net meant a risk of infection 3 times greater than sleeping protected with a net hanged correctly and with no holes (p Conclusion IRS and ITNs have proven to be effective control strategies on the island of Bioko. The choice of one or other strategy is, above all, a question of operational feasibility and availability of local resources.

  7. Malaria vector control by indoor residual insecticide spraying on the tropical island of Bioko, Equatorial Guinea

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    Kuklinski Jaime

    2007-05-01

    Full Text Available Abstract Background A comprehensive malaria control intervention was initiated in February 2004 on Bioko Island, Equatorial Guinea. This manuscript reports on the continuous entomological monitoring of the indoor residual spray (IRS programme during the first two years of its implementation. Methods Mosquitoes were captured daily using window traps at 16 sentinel sites and analysed for species identification, sporozoite rates and knockdown resistance (kdr using polymerase chain reaction (PCR to assess the efficacy of the vector control initiative from December 2003 to December 2005. Results A total of 2,807 and 10,293 Anopheles funestus and Anopheles gambiae s.l. respectively were captured throughout the study period. Both M and S molecular forms of An. gambiae s.s. and Anopheles melas were identified. Prior to the first round of IRS, sporozoite rates were 6.0, 8.3 and 4.0 for An. gambiae s.s., An. melas and An. funestus respectively showing An. melas to be an important vector in areas in which it occurred. After the third spray round, no infective mosquitoes were identified. After the first spray round using a pyrethroid spray the number of An. gambiae s.s. were not reduced due to the presence of the kdr gene but An funestus and An. melas populations declined from 23.5 to 3.1 and 5.3 to 0.8 per trap per 100 nights respectively. After the introduction of a carbamate insecticide in the second round, An. gambiae s.s. reduced from 25.5 to 1.9 per trap per 100 nights and An. funestus and An. melas remained at very low levels. Kdr was found only in the M-form of An. gambiae s.s. with the highest frequency at Punta Europa (85%. Conclusion All three vectors that were responsible for malaria transmission before the start of the intervention were successfully controlled once an effective insecticide was used. Continuous entomological surveillance including resistance monitoring is of critical importance in any IRS based malaria vector control programme

  8. Genotype distribution of cervical human papillomavirus DNA in women with cervical lesions in Bioko, Equatorial Guinea

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    Carro-Campos Patricia

    2009-09-01

    Full Text Available Abstract Background The HVP vaccine is a useful tool for preventing cervical cancer. The purpose of this study is to determine the most frequent HPV genotypes in Equatorial Guinea in order to develop future vaccination strategies to apply in this country. Methods A campaign against cervical cancer was carried out in the area on a total of 1,680 women. 26 of the women, following cytological screening, were treated surgically with a loop electrosurgical excision procedure (LEEP. Cases were studied histologically and were genotyped from paraffin blocks by applying a commercial kit that recognized 35 HPV types. Results Cytological diagnoses included 17 HSIL, 1 LSIL, 5 ASC-H and 3 AGUS. Histological diagnosis resulted in 3 cases of microinvasive squamous cell carcinoma stage IA of FIGO, 9 CIN-3, 8 CIN-2, 2 CIN-1, 3 flat condylomas and mild dysplasia of the endocervical epithelium. Fifteen of twenty-five cases genotyped were positive for HPV (60%. HPV 16 and 33 were identified in four cases each, HPV 58 in two other cases, and HPV 18, 31, 52, and 82 in one case, with one HPV 16 and 58 coinfection. Conclusion The frequency of HPV types in the African area varies in comparison to other regions, particularly in Europe and USA. Vaccination against the five most common HPV types (16, 33, 58, 18, and 31 should be considered in the geographic region of West Africa and specifically in Equatorial Guinea.

  9. Long-Term Urban Market Dynamics Reveal Increased Bushmeat Carcass Volume despite Economic Growth and Proactive Environmental Legislation on Bioko Island, Equatorial Guinea.

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    Cronin, Drew T; Woloszynek, Stephen; Morra, Wayne A; Honarvar, Shaya; Linder, Joshua M; Gonder, Mary Katherine; O'Connor, Michael P; Hearn, Gail W

    2015-01-01

    Bushmeat hunting is extensive in west and central Africa as both a means for subsistence and for commercial gain. Commercial hunting represents one of the primary threats to wildlife in the region, and confounding factors have made it challenging to examine how external factors influence the commercial bushmeat trade. Bioko Island, Equatorial Guinea is a small island with large tracts of intact forest that support sizeable populations of commercially valuable vertebrates, especially endemic primates. The island also has a low human population and has experienced dramatic economic growth and rapid development since the mid-1990's. From October 1997 - September 2010, we monitored the largest bushmeat market on Bioko in Malabo, recording over 197,000 carcasses for sale. We used these data to analyze the dynamics of the market in relation to political events, environmental legislation, and rapid economic growth. Our findings suggest that bushmeat hunting and availability increased in parallel with the growth of Equatorial Guinea's GDP and disposable income of its citizens. During this 13-year study, the predominant mode of capture shifted from trapping to shotguns. Consequently, carcass volume and rates of taxa typically captured with shotguns increased significantly, most notably including intensified hunting of Bioko's unique and endangered monkey fauna. Attempts to limit bushmeat sales, including a 2007 ban on primate hunting and trade, were only transiently effective. The hunting ban was not enforced, and was quickly followed by a marked increase in bushmeat hunting compared to hunting rates prior to the ban. Our results emphasize the negative impact that rapid development and unenforced legislation have had on Bioko's wildlife, and demonstrate the need for strong governmental support if conservation strategies are to be successful at preventing extinctions of tropical wildlife.

  10. Seroprevalence of Human Immunodeficiency Virus, Hepatitis B Virus, Hepatitis C Virus, and Treponema pallidum Infections among Blood Donors on Bioko Island, Equatorial Guinea.

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    Dong-De Xie

    Full Text Available Regular screening of transfusion-transmissible infections (TTIs, such as human immunodeficiency virus (HIV, hepatitis B and hepatitis C virus (HBV and HCV, respectively, and Treponema pallidum, in blood donors is essential to guaranteeing clinical transfusion safety. This study aimed to determine the seroprevalence of four TTIs among blood donors on Bioko Island, Equatorial Guinea (EG.A retrospective survey of blood donors from January 2011 to April 2013 was conducted to assess the presence of HIV, HBV, HCV and T. pallidum. The medical records were analyzed to verify the seroprevalence of these TTIs among blood donations stratified by gender, age and geographical region.Of the total 2937 consecutive blood donors, 1098 (37.39% had a minimum of one TTI and 185 (6.29% harbored co-infections. The general seroprevalence of HIV, HBV, HCV and T. pallidum were 7.83%, 10.01%, 3.71% and 21.51%, respectively. The most frequent TTI co-infections were HBV-T. pallidum 60 (2.04% and HIV-T. pallidum 46 (1.57%. The seroprevalence of HIV, HBV, HCV and T. pallidum were highest among blood donors 38 to 47 years, 18 to 27 years and ≥ 48 years age, respectively (P<0.05. The seroprevalence of TTIs varied according to the population from which the blood was collected on Bioko Island.Our results firstly provide a comprehensive overview of TTIs among blood donors on Bioko Island. Strict screening of blood donors and improved hematological examinations using standard operating procedures are recommended.

  11. The Spanish co-operation programme in Equatorial Guinea: a ten-year review of research and nature conservation in Bioko

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    Castroviejo, Javier; Juste, Javier; Castelo, Ramón; Pérez del Val, Jaime

    1994-01-01

    The Research and Nature Conservation Programme in Equatorial Guinea was launched in 1985, financed by the Spanish Technical Co-operation Agency. The Programme’s main objectives were to: (i) increase scientific research; (ii) set up a Museum of Natural History for the country; (iii) update environmental legislation; (iv) create a network of protected natural areas; (v) promote Equatorial Guinea’s participation in international forums on the environment; (vi) train local per­ sonnel and (vii)...

  12. Limited artemisinin resistance-associated polymorphisms in Plasmodium falciparum K13-propeller and PfATPase6 gene isolated from Bioko Island, Equatorial Guinea

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    Jian Li

    2016-04-01

    Conclusions: This study initially offers an insight of K13-propeller and PfATPase6 polymorphisms on Bioko Island, EG. It suggests no widespread ART resistance or tolerance in the region, and might be helpful for developing and updating guidance for the use of ART-based combination therapies (ACTs.

  13. Increased risks of malaria due to limited residual life of insecticide and outdoor biting versus protection by combined use of nets and indoor residual spraying on Bioko Island, Equatorial Guinea

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    Bradley John

    2012-07-01

    Full Text Available Abstract Background Malaria is endemic on Bioko Island, Equatorial Guinea, with year-round transmission. In 2004 an intensive malaria control strategy primarily based on indoor residual spraying (IRS was launched. The limited residual life of IRS poses particular challenges in a setting with year-round transmission, such as Bioko. Recent reports of outdoor biting by Anopheles gambiae are an additional cause for concern. In this study, the effect of the short residual life of bendiocarb insecticide and of children spending time outdoors at night, on malaria infection prevalence was examined. Methods Data from the 2011 annual malaria indicator survey and from standard WHO cone bioassays were used to examine the relationship between time since IRS, mosquito mortality and prevalence of infection in children. How often children spend time outside at night and the association of this behaviour with malaria infection were also examined. Results Prevalence of malaria infection in two to 14 year-olds in 2011 was 18.4%, 21.0% and 28.1% in communities with median time since IRS of three, four and five months respectively. After adjusting for confounders, each extra month since IRS corresponded to an odds ratio (OR of 1.44 (95% CI 1.15–1.81 for infection prevalence in two to 14 year-olds. Mosquito mortality was 100%, 96%, 81% and 78%, at month 2, 3, 4 and 5 respectively after spraying. Only 4.1% of children spent time outside the night before the survey between the hours of 22.00 and 06.00 and those who did were not at a higher risk of infection (OR 0.87, 95% CI 0.50–1.54. Sleeping under a mosquito net provided additive protection (OR 0.68, 95% CI 0.54–0.86. Conclusions The results demonstrate the epidemiological impact of reduced mosquito mortality with time since IRS. The study underscores that in settings of year-round transmission there is a compelling need for longer-lasting IRS insecticides, but that in the interim, high coverage of long

  14. Check list of the Melastomataceae of Equatorial Guinea

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    Geerinck, Daniel

    2003-12-01

    Full Text Available A chec klist of the Melastomataceae of Equatorial Guinea is presented with 57 taxa. Three species were accepted based only on literature records, their distribution área strongly suggests their presence in Equatorial Guinea. Six species are known from Annobón, 23 from Bioko and 49 from Río Muni. Best-represented genera are Memecylon (10, Calvoa (10 and Tristemma (7. Twenty-six taxa are newly recorded for the country. Heterotis obamae Lejoly & Lisowski is set in synonymy with the previously described Heterotis arenaria Jacq.-Fél.Se presenta el catálogo florístico de la familia Melastomataceae en Guinea Ecuatorial. Se recogen un total de 57 táxones. Tres especies fueron aceptadas teniendo en cuenta solamente la literatura. Su distribución sugiere que su presencia en Guinea Ecuatorial es muy probable. En Annobón están presentes 6 especies, 23 en Bioko y 49 en Río Muni. Los géneros mejor representados son Memecylon (10 especies, Calvoa (10 y Tristemma (7.Veintiséis táxones son citados por primera vez en Guinea Ecuatorial. Se propone Heterotis obamae Lejoly & Lisowski como sinónimo de Heterotis arenaria Jacq.-Fél.

  15. 赤道几内亚比奥科岛G6PD缺乏症分子流行病学研究%Molecular epidemiological investigation of the G6PD deficiency on Bioko Island, Equatorial Guinea

    Institute of Scientific and Technical Information of China (English)

    詹小芬; 陈江涛; 谢东德; 杨辉; 杨惠钿; 杨立业; 陆志为; Santiago-m Monte-Nguba; Juan Carlos Salas Ehapo

    2014-01-01

    目的 探讨非州西部赤道几内亚比奥科岛(Bioko Island)人群的葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症的发生率及基因型. 方法 在2012年1月至5月期间,用荧光斑点法对2 187名比奥科岛当地居民进行G6PD缺乏症筛查.采用高分辨熔解曲线(High-resolution melting,HRM)分析G6PD缺乏的标本的c.202 G>A与c.376 A>G.对HRM筛选不出突变的G6PD酶学缺乏的样本,针对非洲的其他突变类型:c.542 A>T(rs5030872)、c.680 G>A(rs137852328)、c.968 T>C(rs76723693)进行PCR-DNA测序. 结果 赤道几内亚比奥科岛人群的G6PD缺乏症总发生率为8.64% (189/2 187),其中男性84例(9.04%,84/929),女性105例(8.34%,105/1 258),男女检出率比为1.08:1.在189例G6PD缺乏标本中共检出两种基因类型,其中包括G6PD A变异体(c.376 A>G/c.202 G>A)186例(98.41%,186/189G6PD Betica(c.376 A>G/c.968T> C)3例(1.59%3/189). 结论 赤道几内亚比奥科岛是G6PD缺乏症高发区,基因型比较单一.HRM技术可用于非洲地区G6PD缺乏症的临床诊断和流行病学研究.

  16. Equatorial Guinea : Public Investment Management Review

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    Munoz Moreno, Rafael

    2009-01-01

    The chapter offers concise diagnostics of the public investment management (PIM) system in Equatorial Guinea. It provides specific examples of how underperforming institutions throughout the investment process raise the risk of selecting white elephants, reducing the value for money of investment projects and undermining the quality of completed projects. Politically compatible recommendat...

  17. Republic of Equatorial Guinea; Statistical Appendix

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    International Monetary Fund

    2010-01-01

    This report discusses the IMF estimates and projections of the Republic of Equatorial Guinea's central government financial operations, 2001–06; the tax system as of march 2007; public investment program during 2004–06 (execution) and 2007–08 (budgeted); monetary survey during 2001–06; details of central bank and commercial bank assets during 2001–06; fiscal indicators during 2001–06; and estimates on public debts during 2001–06, etc.

  18. 赤道几内亚比奥科岛居民的镰型红细胞病的流行病学调查%Epidemiological investigation of the sickle cell disease in local inhabits on Bioko Island, Equatorial Guinea

    Institute of Scientific and Technical Information of China (English)

    谢东德; 陈江涛; Urbano Monsuy Eyi; Rocio Apicante Mates; Maximo Miko Ondo Obono; Carlos Sala Ehapo; 岳亮; 郭翼华; 古杰超

    2015-01-01

    目的 了解非洲赤道几内亚比奥科岛(Bioko Island)人群的镰刀形红细胞病(sickle cell disease,SCD)的流行病学特点. 方法 在2013年1月至12月期间,采用红细胞镰变试验对1 036名本岛居民进行筛查.用高分辨熔解曲线(high-resolution melting,HRM)分析和PCR-DNA测序法对筛查阳性的标本进行基因型鉴定. 结果 赤道几内亚比奥科岛居民的SCD发生率为16.99% (176/1 036).HRM法与PCR-DNA测序法具有较好的一致性(100%). 结论 比奥科岛是SCD高发区,当地政府和卫生部门应采取有效的干预措施来减少这种疾病的危害.HRM法对SCD的鉴定准确性较高.

  19. Molecular Investigation of Plasmodium falciparum multi-drug resistance gene in Bioko Island,Equatorial Guinea%赤道几内亚Bioko岛的恶性疟原虫多药抗性基因(pfMDR-1)的研究

    Institute of Scientific and Technical Information of China (English)

    卢丹洁; 陈江涛; 谢东德; 杨辉; 詹小芬; 杨惠钿; 杨立业; 陆志为; Santiago-m Monte-Nguba

    2014-01-01

    目的 对赤道几内亚Bioko岛上恶性疟原虫多药抗性基因(pfMDR-1)进行分析,为Bioko 岛的疟疾防控和治疗提供依据.方法 2012年雨季期间采集的恶性疟原虫感染患者样本151份,用巢式PCR技术特异性扩增N86Y、E130K、Y184F、S1034C、N1042D、V1109I、D1246Y耐药分子标记的pfMDR-1基因片段,然后进行测序分析.结果 虫株中共发现了4种不同的单倍型:YEY/SNVD、NEF/SNVD、YEF/SNVD和NEY/SNVD.91.39% (138/151)的样本发现了耐药性位点突变,包括3.31% (5/151)的86Y,29.80%的184F,和58.29%(88/151)的双重突变86Y/184F.结论 结果表明赤道几内亚Bioko岛上的恶性疟原虫株存在较高比例耐药基因突变和耐药复合基因突变,为当地的抗疟疾选用药物提供指导.

  20. Republic of Equatorial Guinea; Staff Report 2006 Article IV Consultation

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    International Monetary Fund

    2006-01-01

    Equatorial Guinea’s macroeconomic performance in the recent period has been broadly satisfactory. Despite the macroeconomic environment, however, progress in alleviating poverty and meeting the MDGs has been slow. Executive Directors welcome the government’s intention to prepare a National Poverty Reduction Strategy. In the meantime, the budget process needs to be modified. The pegged exchange rate regime has served Equatorial Guinea well, providing an anchor to hold down inflation and a ...

  1. Sero-epidemiology and risk factors evaluation of transfusion-transmissible infectious diseases among blood donors on Bioko Island, Equatorial Guinea%赤道几内亚比奥科岛献血者的输血传播感染疾病血清流行学研究和风险因素评估

    Institute of Scientific and Technical Information of China (English)

    谢东德; 杨惠钿; 杨立业; 章光华; 荆磊; 林敏; 陈江涛; Urbano Monsuy Eyi; Rocio Apicante Matesa; Maximo Miko Ondo Obono; Carlos Sala Ehapo; 郑艳芬; 詹小芬; 杨辉

    2014-01-01

    Objective To determine the sero-prevalence of major transfusion-transmissible infections (TTIs) diseases in blood donors on Bioko Island. Methods All consenting blood donors, independence of some unsuitable donors, were submitted to screening with colloidal gold immunochromatographic assay and ELISA for HIV, HBV, HCV and syphilis. Multiple logistic regression analysis was conducted to evaluate risk factors related to each TTIs. Results In total 2 937 blood donors, the sero-prevalence of HIV, HBV, HCV and syphilis were 7.83% (95%CI: 6.85~8.80), 10.01% (95%CI: 8.92~11.10), 3.71% (95%CI: 3.03~4.39) and 21.52%(95%CI:20.02~23.00), respectively. The incidence of co-infections was 6.30%(95%CI:5.42~7.18). Our results also showed that significant higher HIV and syphilis infectious risk in female blood donor than in male counterparts (HIV:AOR=1.50, 95%CI: 1.10~2.04, P=0.010; syphilis:AOR:1.27, 95%CI: 1.02~1.58, P=0.034), and un-planning residential area was a significant risk factor to HIV, HBV and syphilis infection (HIV:AOR=1.66 95%CI: 1.04~2.66, P=0.033; HBV: AOR=1.78, 95%CI: 1.11~2.83, P=0.016; syphilis: AOR=1.73, 95%CI:1.26~2.37, P=0.001). Conclusion The high sero-prevalance of TTIs exists among blood donors on Bioko Island. More effective interventions to improve the access to safe blood should be taken by both the national government and local health departments.%目的:在比奥科岛上献血人群中开展一次输血传播感染疾病(transfusion-transmissible infections,TTIs)的血清流行病学调查。方法用金标法和ELISA对合格献血者血样进行4项输血传播感染疾病的检测,包括人类免疫缺陷病毒(HIV)、乙型肝型病毒(HBV)、丙型肝型病毒(HCV)、梅毒螺旋体(LUES),同时用多元回归分析方法评估TTIs疾病的相关危险因素。结果在2937名献血者中HIV、HBV、HCV和梅毒螺旋体的感染率分别为7.83%(95%CI:6.85~8.80)、10.01%(95%CI:8.92~11.10)、3.71%(95%CI

  2. Clean advice for oily money : Consulting for Equatorial Guinea

    NARCIS (Netherlands)

    Lachotzki, F.W.I.; Karssing, E.D.

    2011-01-01

    Equatorial Guinea is one of the most extraordinary countries in the world, if also one of the most obscure. Its tremendous yearly revenue from the oil concessions it grants in its Gulf of Guinea territorial waters is little known, but so too is its abysmal record on human rights. The deep-rooted cor

  3. Radiation protection in hospitals of Equatorial Guinea

    International Nuclear Information System (INIS)

    With a population of four hundred thousand (400.000) inhabitants and distributed in a territory of 28 thousand (28.000) km2, the use of ionizing radiations for medical practice in Equatorial Guinea is few and decreasing. It is used for diagnostic practices in the main hospitals of the country, where the work burden is not over 20 patients per day. The political, social and economical embryonic development of the country until recently had a negative influence on indicators and health organisations, so that even now the country does not have any radiological protection law, this shortness, in addition with the old architectural structure that x ray tools is lodging, as well as dosimetrical lack of employed staff, put this staff under risk of electromagnetic energy. This is to show the present survey of medical activities with ionizing radiation and to request technical support for implementing suitably the basic standards of radiation protection which will help us as basis for the elaboration outline law, on radiological protection in accordance with the new guidelines of the International Atomic Energy Agency. (author)

  4. Screening of Trypanosoma brucei gambiense in Domestic Livestock and Tsetse Flies from an Insular Endemic Focus (Luba, Equatorial Guinea)

    Science.gov (United States)

    Cordon-Obras, Carlos; García-Estébanez, Carmen; Ndong-Mabale, Nicolás; Abaga, Simón; Ndongo-Asumu, Pedro; Benito, Agustín; Cano, Jorge

    2010-01-01

    Background Sleeping sickness is spread over 36 Sub-Saharan African countries. In West and Central Africa, the disease is caused by Trypanosoma brucei gambiense, which produces a chronic clinical manifestation. The Luba focus (Bioko Island, Equatorial Guinea) has not reported autochthonous sleeping sickness cases since 1995, but given the complexity of the epidemiological cycle, the elimination of the parasite in the environment is difficult to categorically ensure. Methodology/Principal Findings The aim of this work is to assess, by a molecular approach (Polymerase Chain Reaction, PCR), the possible permanence of T. b. gambiense in the vector (Glossina spp.) and domestic fauna in order to improve our understanding of the epidemiological situation of the disease in an isolated focus considered to be under control. The results obtained show the absence of the parasite in peridomestic livestock but its presence, although at very low rate, in the vector. On the other hand, interesting entomological data highlight that an elevated concentration of tsetse flies was observed in two out of the ten villages considered to be in the focus. Conclusions These findings demonstrate that even in conditions of apparent control, a complete parasite clearance is difficult to achieve. Further investigations must be focused on animal reservoirs which could allow the parasites to persist without leading to human cases. In Luba, where domestic livestock are scarcer than other foci in mainland Equatorial Guinea, the epidemiological significance of wild fauna should be assessed to establish their role in the maintenance of the infection. PMID:20544031

  5. Re-imaging the Modernity of Sierra Leone and Equatorial Guinea: Africa past and Africa present

    OpenAIRE

    Codling, Rosetta

    2011-01-01

    This paper engages the concept of the imposed Modernity of Europe upon the African republics of Sierra Leone and Equatorial Guinea. Evidence of the encroachment of a ‘false’ Modernity upon Africa’s Sierra Leone and Equatorial Guinea are chronicled in the works of Donato Ndongo (Shadows of Your Black Memory) and Syl Cheney Coker (The Last Harmattan of Alusine Dunbar).

  6. Artesunate/amodiaquine malaria treatment for Equatorial Guinea (Central Africa).

    Science.gov (United States)

    Charle, Pilar; Berzosa, Pedro; de Lucio, Aida; Raso, José; Nseng Nchama, Gloria; Benito, Agustín

    2013-06-01

    The objectives of this study were: 1) to evaluate the safety and efficacy of combination artesunate (AS)/amodiaquine (AQ) therapy, and 2) to determine the difference between recrudescence and resistance. An in vivo efficacy study was conducted in Equatorial Guinea. A total of 122 children 6-59 months of age from two regional hospitals were randomized and subjected to a 28-day clinical and parasitological follow-up. A blood sample on Whatman paper was taken on Days 0, 7, 14, 21, and 28 or on any day in cases of treatment failure, with the parasite DNA then being extracted for molecular analysis purposes. A total of 4 children were excluded, and 9 cases were lost to follow-up. There were 17 cases of late parasitological failure, 3 cases of late clinical failure, and 89 cases of adequate clinical and parasitological response. The parasitological failure rate was 18.3% (20 of 109) and the success rate 81.70% (95% confidence interval [72.5-87.9%]). After molecular correction, real treatment efficacy stood at 97.3%. Our study showed the good efficacy of combination AS/AQ therapy. This finding enabled this treatment to be recommended to Equatorial Guinea's National Malaria Control Program to change the official treatment policy as of March 2008.

  7. Las labiadas (Lamiaceae) de Guinea Ecuatorial

    OpenAIRE

    Morales, R.

    2011-01-01

    The identification of 223 collections of the Lamiaceae family, from Bioko island, Rio Muni (Equatorial Guinea mainland) and Annobon, corresponding to 14 genera and 28 species, is presented. A key of genera and, in each genus, a key of species are included. The basionym and type material, a brief description, the known chromosomic numbers, the distribution area and some known popular uses from each species, also included are photographs of sheets and distribution maps. Some biogeographical asp...

  8. Yu Zhengsheng Attends Reception Marking 45th Anniversary Of China-Equatorial Guinea Diplomatic Relations

    Institute of Scientific and Technical Information of China (English)

    Xu; Liya

    2015-01-01

    On April 29,the CPAFFC held a reception in Beijing to celebrate the 45th anniversary of the establishment of diplomatic relations between China and Equatorial Guinea.Yu Zhengsheng,Chairman of the National Committee of the Chinese People’s Political Consultative Conference(CPPCC)and Teodoro Obiang Nguema Mbasogo,President of Equatorial Guinea,spoke on the occasion.Among the audience of some 150were Abdul’ahat Abdulrixit,former

  9. Bryophytes from the Republic of Equatorial Guinea (West-Central Africa) : 2., bryophytes collected by Emilio Guinea (1907-1985) in the Island of Bioco in 1947

    OpenAIRE

    Infante, Marta; Heras, Patxi; Buck, William R.

    1997-01-01

    Some unidentified samples of bryophytes collected by Emilio Guinea in Bioco (Equatorial Guinea) in 1947 have been studied. Twenty-seven taxa are the result of this study, nine of them being new for Equatorial Guinea and two new for the island of Bioco. Se han estudiado varias muestras de briófitos sin identificar recogidas por Emilio Guinea en Bioco (Guinea Ecuatorial) en 1947. Veintisiete taxones son el resultado de este estudio, siendo nueve de ellos novedad para Guinea Ecuatorial y dos ...

  10. Decisive Thaw: The Changing Pattern of Relations between Nigeria and Equatorial Guinea, 1980-2005

    Directory of Open Access Journals (Sweden)

    David Aworawo

    2010-04-01

    Full Text Available This article examines the nature and changing pattern of relations between Nigeria and Equatorial Guinea from 1980-2005. It states that relations between the countries improved tremendously in the quarter century covered in this study compared to the two decades preceding that time frame (1960-1980 due to of a number of domesticpolitical and economic changes that occurred in both countries, as well as the transformation of the international system in the late 1980s and early 1990s. The paper explores the specific changes that took place in Nigerian-Equatorial Guinean relations from1980 onwards and the factors that influenced them. The termination of the brutal and violent rule of President Macias Nguema in Equatorial Guinea opened the way for improved relations between Nigeria and Equatorial Guinea. The shift from dependence on cocoa to petroleum exports in Equatorial Guinea also helped to promote cordial relations since the ill-treatment of Nigerian workers in Equatorial Guinea’s cocoa plantations had been a thorny issue in Nigerian-Equatorial Guinean relations in previous decades. The end of the Cold War and apartheid between 1989 and 1994 were also important factors that shaped relations. All these were issues that had previously negatively affected cordial relations between the countries. Thisarticle therefore discusses relations between Nigeria and Equatorial Guinea within the context of the post-Cold War international system and intra-African relations. It also argues that although improvements were recorded in Nigerian-Equatorial Guinean relations between 1980 and 2005, there remain numerous avenues that could be explored for yet better relations.

  11. Survey of ICT and Education in Africa : Equatorial Guinea Country Report

    OpenAIRE

    Fall, Babacar

    2007-01-01

    This short country report, a result of a larger Information for Development Program (infoDev)-supported survey of the Information and Communication Technologies (ICT) in education in Africa, provides a general overview of current activities and issues related to ICT use in education in the country. In Equatorial Guinea, there is no specific policy concerning ICT, although attempts to impro...

  12. Self-reported adherence to antiretroviral therapy in HIV+ population from Bata, Equatorial Guinea.

    Science.gov (United States)

    Salmanton-García, Jon; Herrador, Zaida; Ruiz-Seco, Pilar; Nzang-Esono, Jesús; Bendomo, Veronica; Bashmakovic, Emma; Nseng-Nchama, Gloria; Benito, Agustín; Aparicio, Pilar

    2016-01-01

    The human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome (AIDS) represent a serious public health problem in Equatorial Guinea, with a prevalence of 6.2% among adults. the high-activity antiretroviral treatment (HAART) coverage data is 10 points below the overall estimate for Sub-Saharan Africa, and only 61% patients continue with HAART 12 months after it started. This study aims to assess HAART adherence and related factors in Litoral Province of Equatorial Guinea. In this cross-sectional study, socio-demographic and clinical data were collected at Regional Hospital of Bata, during June-July 2014. Adherence to treatment was assessed by using the Spanish version of CEAT-VIH. Bivariate and linear regression analyses were employed to assess HAART adherence-related factors. We interviewed 50 men (35.5%) and 91 women (64.5%), with a mean age of 47.7 ± 8.9 and 36.2 ± 11.2, respectively (p VIH score varied by ethnic group (p = .005). There was a positive correlation between CEAT-VIH score and current CD4 T-cells count (p = .013). The Cronbach's α value was 0.52. To our knowledge, this is the first study to assess HAART adherence in Equatorial Guinea. Internal reliability for CEAT-VIH was low, nonetheless the positive correlation between the CEAT-VIH score and the immunological status of patients add value to our findings. Our results serve as baseline for future research and will also assist stakeholders in planning and undertaking contextual and evidence-based policy initiatives.

  13. Corporate philanthropy and conflicts of interest in public health: ExxonMobil, Equatorial Guinea, and malaria.

    Science.gov (United States)

    Shah, Naman K

    2013-01-01

    Equatorial Guinea, the most prosperous country in Africa, still bears a large malaria burden. With massive wealth from oil reserves, and nearly half its population living in island ecotypes favourable for malaria control, only poor governance can explain continued parasite burden. By financially backing the country's dictator and other officials through illicit payments, the oil company ExxonMobil contributed to the state's failure. Now ExxonMobil, having helped perpetuate malaria in Equatorial Guinea, gives money to non-governmental organizations, charitable foundations, and universities to advocate for and undertake malaria work. How, and on what terms, can public health engage with such an actor? We discuss challenges in the identification and management of conflicts of interest in public health activities. We reviewed the business and foundation activities of ExxonMobil and surveyed organizations that received ExxonMobil money about their conflict of interest policies. Reforms in ExxonMobil's business practices, as well as its charitable structure, and reforms in the way public health groups screen and manage conflicts of interest are needed to ensure that any relationship ultimately improves the health of citizens. PMID:23172050

  14. From the African Coast, the invention of two territories: Equatorial Guinea and Ivory Coast

    Directory of Open Access Journals (Sweden)

    Adjoa Nathalie Chiyé Kessé

    2014-08-01

    Full Text Available From the African coast starts Latin American history and part of Europe’s. This article includes a comprehensive analysis on the cultural influence of Africa especially Equatorial Guinea and Côte d’Ivoire in Latin America. From the first European incursions into African coast (xvi century and throughout the colonial era, the paper highlights interethnic relations that occurred following the meeting and coexistence between cultures of both continents, an analysis that is essential to study the survival of traditions, beliefs and African customs that survive today in many regions of Latin America. Considering the importance now given to the recovery of identity traits of the past for studies of multi-ethnicity and re-construction of identities, this article can be used by researchers at Afro-descendance, notable in Latin America, whose research is related to African identity traits in their respective nations. Equatorial Guinea was a Spanish colony along with the Protectorate of Morocco and Western Sahara. The duration of this colony ran from 1885 to 1968. In 1926, it became the Spanish Guinea, and in 1968 it acquired its independance from Spain while retaining the Spanish cultural architecture. Furthermore, the French presence in this first stage of the conquest in Côte d’Ivoire, is provided by the army. The colonial authorities in Paris were not yet sufficiently organized to move their representatives to what was then known as the Poor or Bad People Coast or Coast of teeth. It was the military from Senegal, as base of the French colonial army who assumed the conquest and organization of the Ivorian territory for immediate exploitation of economic resources. It is this improvised framework without legal planning, which led to the idea of the invention of Africa supported by Valentin Mudimbe (1988 and Achille Mbembe (2000.

  15. Novitates Rio Munis 2. A new species of Begonia section Loasibegonia (Begoniaceae) from the Monte Alen region, Equatorial Guinea

    NARCIS (Netherlands)

    Sosef, M.S.M.; Nguema Miyono, N.S.

    2010-01-01

    A new, yellow-flowering species of Begonia, B. aequatoguineensis, is being described from the Monte Alen region in Equatorial Guinea. It belongs to the section Loasibegonia and supports the idea that the Monte Alen region harbours an exceptionally high biodiversity and possibly represents a former P

  16. Novitates Rio Munis 2. A new species of Begonia section Loasibegonia (Begoniaceae) from the Monte Alen region, Equatorial Guinea.

    NARCIS (Netherlands)

    Sosef, M.S.M.; Nguema Miyono, N.S.

    2010-01-01

    A new, yellow-flowering species of Begonia, B. aequatoguineensis, is being described from the Monte Alen region in Equatorial Guinea. It belongs to the section Loasibegonia and supports the idea that the Monte Alen region harbours an exceptionally high biodiversity and possibly represents a former P

  17. Taxonomy of Atlantic Central African Orchids 1. A New Species of Angraecum set. Pectinaria (Orchidaceae) from Gabon and Equatorial Guinea.

    NARCIS (Netherlands)

    Stévart, T.; Cawoy, V.; Damen, T.H.J.; Droissart, V.

    2010-01-01

    During a recent survey of Atlantic central African orchids, we collected four orchid specimens in Rio Muni (Equatorial Guinea) that share the general morphology of Angraecum gabonense, the most frequent member of Angraecum section Pectinaria in Central Africa, but differ in leaf shape and flower siz

  18. Treatment Adherence of Tuberculosis Patients Attending Two Reference Units in Equatorial Guinea.

    Science.gov (United States)

    Fagundez, Gabriela; Perez-Freixo, Hugo; Eyene, Juan; Momo, Juan Carlos; Biyé, Lucia; Esono, Teodoro; Ondó Mba Ayecab, Marcial; Benito, Agustín; Aparicio, Pilar; Herrador, Zaida

    2016-01-01

    Equatorial Guinea has one of the highest burden of tuberculosis (TB) in Africa. Incomplete adherence to TB treatment has been identified as one of the most serious remaining problem in tuberculosis control. The following study is aimed at determining the adherence to anti-tuberculosis treatment in Equatorial Guinea and its determinants, as well as at assessing the knowledge of the people about the disease. In this cross-sectional study, participants were recruited by non-probabilistic consecutive sampling amongst patients who attended the reference units for TB in Bata and Malabo between March and July 2015. Socio-demographic and clinical data were collected. Adherence to treatment and knowledge about TB were assessed by Morisky-Green-Levine and Batalla tests and a questionnaire on adherence related factors specifically prepared for this research. Descriptive statistics were computed to summarize the data and bivariate analyses by adherence profile were performed with χ2 test for categorical data. A total of 98 patients with TB were interviewed. 63.27% of interviewees had good knowledge about TB (Batalla test) while 78.57% of respondents were adherent according to the Morisky-Green-Levine test. A low educational level, lack of family support and lack of medical advice about the disease were significantly associated to lower adherence level. Patients with re-infection (due to relapse or treatment failure) and those who have suffered from drug shortages were also less adherents. The National Programme for TB Control should consider improving the early diagnosis and follow-up of TB cases, as well as the implementation of all components of DOTS (Directly observed Treatment, short-course) strategy all over the country.

  19. Treatment Adherence of Tuberculosis Patients Attending Two Reference Units in Equatorial Guinea.

    Science.gov (United States)

    Fagundez, Gabriela; Perez-Freixo, Hugo; Eyene, Juan; Momo, Juan Carlos; Biyé, Lucia; Esono, Teodoro; Ondó Mba Ayecab, Marcial; Benito, Agustín; Aparicio, Pilar; Herrador, Zaida

    2016-01-01

    Equatorial Guinea has one of the highest burden of tuberculosis (TB) in Africa. Incomplete adherence to TB treatment has been identified as one of the most serious remaining problem in tuberculosis control. The following study is aimed at determining the adherence to anti-tuberculosis treatment in Equatorial Guinea and its determinants, as well as at assessing the knowledge of the people about the disease. In this cross-sectional study, participants were recruited by non-probabilistic consecutive sampling amongst patients who attended the reference units for TB in Bata and Malabo between March and July 2015. Socio-demographic and clinical data were collected. Adherence to treatment and knowledge about TB were assessed by Morisky-Green-Levine and Batalla tests and a questionnaire on adherence related factors specifically prepared for this research. Descriptive statistics were computed to summarize the data and bivariate analyses by adherence profile were performed with χ2 test for categorical data. A total of 98 patients with TB were interviewed. 63.27% of interviewees had good knowledge about TB (Batalla test) while 78.57% of respondents were adherent according to the Morisky-Green-Levine test. A low educational level, lack of family support and lack of medical advice about the disease were significantly associated to lower adherence level. Patients with re-infection (due to relapse or treatment failure) and those who have suffered from drug shortages were also less adherents. The National Programme for TB Control should consider improving the early diagnosis and follow-up of TB cases, as well as the implementation of all components of DOTS (Directly observed Treatment, short-course) strategy all over the country. PMID:27622461

  20. Treatment Adherence of Tuberculosis Patients Attending Two Reference Units in Equatorial Guinea

    Science.gov (United States)

    Eyene, Juan; Momo, Juan Carlos; Biyé, Lucia; Esono, Teodoro; Ondó Mba Ayecab, Marcial; Benito, Agustín; Aparicio, Pilar

    2016-01-01

    Equatorial Guinea has one of the highest burden of tuberculosis (TB) in Africa. Incomplete adherence to TB treatment has been identified as one of the most serious remaining problem in tuberculosis control. The following study is aimed at determining the adherence to anti-tuberculosis treatment in Equatorial Guinea and its determinants, as well as at assessing the knowledge of the people about the disease. In this cross-sectional study, participants were recruited by non-probabilistic consecutive sampling amongst patients who attended the reference units for TB in Bata and Malabo between March and July 2015. Socio-demographic and clinical data were collected. Adherence to treatment and knowledge about TB were assessed by Morisky-Green-Levine and Batalla tests and a questionnaire on adherence related factors specifically prepared for this research. Descriptive statistics were computed to summarize the data and bivariate analyses by adherence profile were performed with χ2 test for categorical data. A total of 98 patients with TB were interviewed. 63.27% of interviewees had good knowledge about TB (Batalla test) while 78.57% of respondents were adherent according to the Morisky-Green-Levine test. A low educational level, lack of family support and lack of medical advice about the disease were significantly associated to lower adherence level. Patients with re-infection (due to relapse or treatment failure) and those who have suffered from drug shortages were also less adherents. The National Programme for TB Control should consider improving the early diagnosis and follow-up of TB cases, as well as the implementation of all components of DOTS (Directly observed Treatment, short-course) strategy all over the country. PMID:27622461

  1. Spatial and temporal variability of the Glossina palpalis palpalis population in the Mbini focus (Equatorial Guinea

    Directory of Open Access Journals (Sweden)

    Nzambo-Ondo Sisinio

    2007-08-01

    Full Text Available Abstract Background Human African Trypanosomiasis is a vector-borne parasitic disease. The geographical distribution of the disease is linked to the spatial distribution of the tsetse fly. As part of a control campaign using traps, the spatial and temporal variability is analysed of the glossina populations present in the Mbini sleeping sickness foci (Equatorial Guinea. Results A significant drop in the annual mean of the G. p. palpalis apparent density was noted from 2004 to 2005, although seasonal differences were not observed. The apparent density (AD of G. p. palpalis varies significantly from one biotope to another. The fish dryers turned out to be zones with the greatest vector density, although the AD of G. p. palpalis fell significantly in all locations from 2004 to 2005. Conclusion Despite the tsetse fly density being relatively low in fish dryers and jetties, the population working in those zones would be more exposed to infection. The mono-pyramidal traps in the Mbini focus have been proven to be a useful tool to control G. p. palpalis, even though the activity on the banks of the River Wele needs to be intensified. The application of spatial analysis techniques and geographical information systems are very useful tools to discriminate zones with high and low apparent density of G. p. palpalis, probably associated with different potential risk of sleeping sickness transmission.

  2. Transmission of malaria and genotypic variability of Plasmodium falciparum on the Island of Annobon (Equatorial Guinea

    Directory of Open Access Journals (Sweden)

    Ondo Melchor

    2007-10-01

    Full Text Available Abstract Background Malaria transmission in Equatorial Guinea and its space-time variability has been widely studied, but there is not much information about the transmission of malaria on the small island of Annobon. In 2004, two transversal studies were carried out to establish the malaria transmission pattern on Annobon and analyse the circulating Plasmodium falciparum allelic forms. Methods A blood sample was taken from the selected children in order to determine Plasmodium infection by microscopical examination and by semi-nested multiplex PCR. The diversity of P. falciparum circulating alleles was studied on the basis of the genes encoding for the merozoite surface proteins, MSP-1 and MSP-2 of P. falciparum. Results The crude parasite rate was 17% during the dry season and 60% during the rainy season. The percentage of children sleeping under a bed net was over 80% in the two surveys. During the rainy season, 33.3% of the children surveyed were anaemic at the time of the study. No association was found between the crude parasite rate, the use of bed nets and gender, and anaemia. However, children between five and nine years of age were five times less at risk of being anaemic than those aged less than one year. A total of 28 populations of the three allelic families of the msp-1 gene were identified and 39 of the msp-2 gene. The variability of circulating allelic populations is significantly higher in the rainy than in the dry season, although the multiplicity of infections is similar in both, 2.2 and 1.9 respectively. Conclusion Based on the high degree of geographical isolation of the Annobon population and the apparent marked seasonality of the transmission, it is feasible to believe that malaria can be well controlled from this small African island.

  3. Las labiadas (Lamiaceae de Guinea Ecuatorial

    Directory of Open Access Journals (Sweden)

    Morales, R.

    2011-12-01

    Full Text Available The identification of 223 collections of the Lamiaceae family, from Bioko island, Rio Muni (Equatorial Guinea mainland and Annobon, corresponding to 14 genera and 28 species, is presented. A key of genera and, in each genus, a key of species are included. The basionym and type material, a brief description, the known chromosomic numbers, the distribution area and some known popular uses from each species, also included are photographs of sheets and distribution maps. Some biogeographical aspects about the generic and specific distribution in the studied area are discussed. Calaminta pseudosimensis (Brenan R. Morales, comb. nov. is proposed.

    Se estudian e identifican 223 colecciones de plantas vasculares que corresponden a 14 géneros y 28 especies pertenecientes a la familia Lamiaceae procedentes de las islas de Bioko, Annobón y Río Muni (Guinea Ecuatorial continental. Se incluye una clave de géneros y en cada género, si ha lugar, clave de especies. Se citan de cada especie su basiónimo y material tipo, se incluyen una breve descripción y números cromosomáticos, área de distribución y usos populares conocidos. Se aportan fotografías de pliegos y mapas de distribución. Se discuten aspectos bio - geográficos dentro de la distribución genérica y específica en el área estudiada. Se propone la combinación Calaminta pseudosimensis (Brenan R. Morales, comb. nov.

  4. The role of the New Guinea cross-equatorial flow in the interannual variability of the western North Pacific summer monsoon

    International Nuclear Information System (INIS)

    The western North Pacific (WNP) monsoon trough from 1958 to 2001 shows a binary-like feature in August and September, with more than half being either an imposing presence or a total absence. One of the major moisture sources maintaining the WNP monsoon trough is the low-level moisture advection laterally driven by the low-level cross-equatorial flow that originates from the Banda Sea and Solomon Sea. By decomposing contributions to the cross-equatorial flow based on the method proposed by Back and Bretherton in 2009, the boundary-layer pressure gradient in the Maritime Continent plays a major role. This pressure gradient is further found to be associated with the densely packed sea surface temperature (SST) gradient near the equator around New Guinea, which is well correlated with the SST anomalies in the equatorial eastern Pacific, a concurrent El Niño/Southern Oscillation (ENSO) condition. (paper)

  5. Molecular evidence of a Trypanosoma brucei gambiense sylvatic cycle in the human african trypanosomiasis foci of Equatorial Guinea.

    Science.gov (United States)

    Cordon-Obras, Carlos; Rodriguez, Yasmin Fermin; Fernandez-Martinez, Amalia; Cano, Jorge; Ndong-Mabale, Nicolas; Ncogo-Ada, Policarpo; Ndongo-Asumu, Pedro; Aparicio, Pilar; Navarro, Miguel; Benito, Agustin; Bart, Jean-Mathieu

    2015-01-01

    Gambiense trypanosomiasis is considered an anthroponotic disease. Consequently, control programs are generally aimed at stopping transmission of Trypanosoma brucei gambiense (T. b. gambiense) by detecting and treating human cases. However, the persistence of numerous foci despite efforts to eliminate this disease questions this strategy as unique tool to pursue the eradication. The role of animals as a reservoir of T. b. gambiense is still controversial, but could partly explain maintenance of the infection at hypo-endemic levels. In the present study, we evaluated the presence of T. b. gambiense in wild animals in Equatorial Guinea. The infection rate ranged from 0.8% in the insular focus of Luba to more than 12% in Mbini, a focus with a constant trickle of human cases. The parasite was detected in a wide range of animal species including four species never described previously as putative reservoirs. Our study comes to reinforce the hypothesis that animals may play a role in the persistence of T. b. gambiense transmission, being particularly relevant in low transmission settings. Under these conditions the integration of sustained vector control and medical interventions should be considered to achieve the elimination of gambiense trypanosomiasis.

  6. Molecular evidence of a Trypanosoma brucei gambiense sylvatic cycle in the human african trypanosomiasis foci of Equatorial Guinea

    Science.gov (United States)

    Cordon-Obras, Carlos; Rodriguez, Yasmin Fermin; Fernandez-Martinez, Amalia; Cano, Jorge; Ndong-Mabale, Nicolas; Ncogo-Ada, Policarpo; Ndongo-Asumu, Pedro; Aparicio, Pilar; Navarro, Miguel; Benito, Agustin; Bart, Jean-Mathieu

    2015-01-01

    Gambiense trypanosomiasis is considered an anthroponotic disease. Consequently, control programs are generally aimed at stopping transmission of Trypanosoma brucei gambiense (T. b. gambiense) by detecting and treating human cases. However, the persistence of numerous foci despite efforts to eliminate this disease questions this strategy as unique tool to pursue the eradication. The role of animals as a reservoir of T. b. gambiense is still controversial, but could partly explain maintenance of the infection at hypo-endemic levels. In the present study, we evaluated the presence of T. b. gambiense in wild animals in Equatorial Guinea. The infection rate ranged from 0.8% in the insular focus of Luba to more than 12% in Mbini, a focus with a constant trickle of human cases. The parasite was detected in a wide range of animal species including four species never described previously as putative reservoirs. Our study comes to reinforce the hypothesis that animals may play a role in the persistence of T. b. gambiense transmission, being particularly relevant in low transmission settings. Under these conditions the integration of sustained vector control and medical interventions should be considered to achieve the elimination of gambiense trypanosomiasis. PMID:26257727

  7. Molecular Evidence of a Trypanosoma brucei gambiense Sylvatic Cycle in the Human African Trypanosomiasis Foci of Equatorial Guinea

    Directory of Open Access Journals (Sweden)

    Carlos eCordon-Obras

    2015-07-01

    Full Text Available Gambiense trypanosomiasis is considered an anthroponotic disease. Consequently, control programs are generally aimed at stopping transmission of Trypanosoma brucei gambiense (T. b. gambiense by detecting and treating human cases. However, the persistence of numerous foci despite efforts to eliminate this disease questions this strategy as unique tool to pursue the eradication. The role of animals as a reservoir of T. b. gambiense is still controversial, but could partly explain maintenance of the infection at hypo-endemic levels. In the present study, we evaluated the presence of T. b. gambiense in wild animals in Equatorial Guinea. The infection rate ranged from 0.8% in the insular focus of Luba to more than 12% in Mbini, a focus with a constant trickle of human cases. The parasite was detected in a wide range of animal species including four species never described previously as putative reservoirs. Our study comes to reinforce the hypothesis that animals may play a role in the persistence of T. b. gambiense transmission, being particularly relevant in low transmission settings. Under these conditions the integration of sustained vector control and medical interventions should be considered to achieve the elimination of Gambiense trypanosomiasis.

  8. Integrating occurrence and detectability patterns based on interview data: a case study for threatened mammals in Equatorial Guinea

    Science.gov (United States)

    Martínez-Martí, Chele; Jiménez-Franco, María V.; Royle, J. Andrew; Palazón, José A.; Calvo, José F.

    2016-01-01

    Occurrence models that account for imperfect detection of species are increasingly used for estimating geographical range, for determining species-landscape relations and to prioritize conservation actions worldwide. In 2010, we conducted a large-scale survey in Río Muni, the mainland territory of Equatorial Guinea, which aimed to estimate the probabilities of occurrence and detection of threatened mammals based on environmental covariates, and to identify priority areas for conservation. Interviews with hunters were designed to record presence/absence data of seven species (golden cat, leopard, forest elephant, forest buffalo, western gorilla, chimpanzee and mandrill) in 225 sites throughout the region. We fitted single season occupancy models and recently developed models which also include false positive errors (i.e. species detected in places where it actually does not occur), which should provide more accurate estimates for most species, which are susceptible to mis-identification. Golden cat and leopard had the lowest occurrence rates in the region, whereas primates had the highest rates. All species, except gorilla, were affected negatively by human settlements. The southern half of Río Muni showed the highest occurrence of the species studied, and conservation strategies for ensuring the persistence of threatened mammals should be focused on this area.

  9. Rural-Urban Differences in Household Treatment-Seeking Behaviour for Suspected Malaria in Children at Bata District, Equatorial Guinea.

    Directory of Open Access Journals (Sweden)

    Maria Romay-Barja

    Full Text Available Malaria remains a major cause of morbidity and mortality among children under five years old in Equatorial Guinea. However, little is known about the community management of malaria and treatment-seeking patterns. We aimed to assess symptoms of children with reported malaria and treatment-seeking behaviour of their caretakers in rural and urban areas in the Bata District.A cross-sectional study was conducted in the district of Bata and 440 houses were selected from 18 rural villages and 26 urban neighbourhoods. Differences between rural and urban caregivers and children with reported malaria were assessed through the chi-squared test for independence of categorical variables and the t-Student or the non-parametric Mann-Whitney test for normally or not-normally distributed continuous variables, respectively.Differences between rural and urban households were observed in caregiver treatment-seeking patterns. Fever was the main symptom associated with malaria in both areas. Malaria was treated first at home, particularly in rural areas. The second step was to seek treatment outside the home, mainly at hospital and Health Centre for rural households and at hospital and private clinic for urban ones. Artemether monotherapy was the antimalarial treatment prescribed most often. Households waited for more than 24 hours before seeking treatment outside and delays were longest in rural areas. The total cost of treatment was higher in urban than in rural areas in Bata.The delays in seeking treatment, the type of malaria therapy received and the cost of treatment are the principal problems found in Bata District. Important steps for reducing malaria morbidity and mortality in this area are to provide sufficient supplies of effective antimalarial drugs and to improve malaria treatment skills in households and in both public and private sectors.

  10. Los Yacimientos de Arcillas de la Isla de Bioko. Caracterización y Aplicaciones Tecnológicas.

    OpenAIRE

    Costafreda Mustelier, Jorge Luis; Leyva Rodriguez, Carlos; Parra y Alfaro, José Luis; Ndong Bacale, Mateo

    2012-01-01

    Las recientes investigaciones realizadas en los potentes yacimientos de arcillas que se encuentran en la Ciudad de Malabo (Bioko Norte), República de Guinea Ecuatorial, revelaron la presencia mayoritaria de una fase compuesta por sepiolita, acompañada por especies secundarias de feldespato, caolinita, hematita, moscovita e illita. Los análisis por microscopía electrónica de barrido (MEB), difracción de rayos x (DRX) y agregado orientado con etilenglicol (AO), indican un comportamiento simil...

  11. Nutritional and socio-economic factors associated with Plasmodium falciparum infection in children from Equatorial Guinea: results from a nationally representative survey

    Directory of Open Access Journals (Sweden)

    Bernis Cristina

    2009-10-01

    Full Text Available Abstract Background Malaria has traditionally been a major endemic disease in Equatorial Guinea. Although parasitaemia prevalence on the insular region has been substantially reduced by vector control in the past few years, the prevalence in the mainland remains over 50% in children younger than five years. The aim of this study is to investigate the risk factors for parasitaemia and treatment seeking behaviour for febrile illness at country level, in order to provide evidence that will reinforce the EG National Malaria Control Programme. Methods The study was a cross-sectional survey of children 0 to 5 years old, using a multistaged, stratified, cluster-selected sample at the national level. It included a socio-demographic, health and dietary questionnaires, anthropometric measurements, and thick and thin blood smears to determine the Plasmodium infection. A multivariate logistic regression model was used to determine risk factors for parasitaemia, taking into account the cluster design. Results The overall prevalence of parasitemia was 50.9%; it was higher in rural (58.8% compared to urban areas (44.0%, p = 0.06. Age was positively associated with parasitemia (p Conclusion Results suggest that a national programme to fight malaria in Equatorial Guinea should take into account the differences between rural and urban communities in relation to risk factors for parasitaemia and treatment seeking behaviour, integrate nutrition programmes, incorporate campaigns on the importance of early treatment, and target appropriately for bed nets to reach the under-fives.

  12. A Colorful Equatorial Wonderland

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Papua New Guinea (PNG) is one of the least visited countries in the world... a last frontier for international travelers. PNG is a colorful equatorial wonderland as well as a living example of human's culture 1000 years ago.

  13. The Development of Chinese Companies in African Construction Market:A Case of Equatorial Guinea%中国公司在非洲建筑市场的发展:赤道几内亚案例

    Institute of Scientific and Technical Information of China (English)

    龚财君

    2013-01-01

      在中国的“走出去”战略要求下,中国公司大量进入非洲建筑市场。以赤道几内亚为例,本文描述了中国公司在赤道几内亚承接的项目情况、经营情况、成功原因以及存在的问题。%A large number of Chinese companies enter the African construction market based on the requirements for China's "Going Global" strategy. Taking Equatorial Guinea for example, the problems, reasons for the success, operating conditions and projects situation which is undertook by Chinese companies in Equatorial Guinea were described in this article.

  14. Efficacy of Artesunate + Sulphadoxine-Pyrimethamine (AS + SP and Amodiaquine + Sulphadoxine-Pyrimethamine (AQ + SP for Uncomplicated falciparum Malaria in Equatorial Guinea (Central Africa

    Directory of Open Access Journals (Sweden)

    Pilar Charle

    2009-01-01

    Full Text Available Objectives. The objectives of the study were (i to evaluate the efficacy of combination drugs, such as artesunate + sulphadoxine-pyrimethamine (AS + SP and amodiaquine + sulphadoxine-pyripethamine (AQ + SP in treatment of uncomplicated falciparum malaria (ii to differentiate recrudescence from reinfection by analysing msp-1 and msp-2 genes of Plasmodium falciparum in treatment failure cases. Methods. We carried out an in vivo study in the year 2005 in 206 children between 6 to 59 months age groups. Of the 206, 120 received AQ + SP, and 86 received AS + SP. A clinical and parasitological followup during 14 days was undertaken. Finger-prick blood sample from each patient was taken on Whatman filter paper (no. 3 on days 0, 7, 14 and also the day when the parasite and symptoms reappeared for PCR analysis. Results. Late treatment failure was observed in 3.5% (4/114 with AQ + SP, and 2.5% (2/79 with AS + SP. The success rate was 96.5% with AQ + SP and 97.5% with AS + SP. No deaths and severe reactions were recorded. Out of the 6 treatment failure cases, one was reinfection as observed by PCR analysis of msp-1 and msp-2 genes on day 14. Discussion. Both the combinations found to be efficacious and safe and could be used as a first-line treatment for uncomplicated falciparum malaria in Equatorial Guinea.

  15. Site Design Work Summary for City Power Grid Project of Ebebiyin in Equatorial Guinea%赤道几内亚埃贝比因城市电网工程实践

    Institute of Scientific and Technical Information of China (English)

    李鸿杰; 张祖辉; 钱龙

    2014-01-01

    This paper introduces the city power grid site design of Ebebiyin in Equatorial Guinea. The project includes diesel power plant construction, renovation, equipment in-stallation, commissioning and city power grid equipment installation, cable laying, equip-ment commissioning.%本文介绍了赤道几内亚埃贝比因市电网项目,项目内容包括柴油发电站的土建、装修、设备安装、调试,城市电网的设备安装、电缆敷设、设备的运行调试。

  16. What does remain in Equatorial Guinea of the Spanish education? From the colonial education to the current reality ¿Qué queda en Guinea Ecuatorial de la educación española? de la educación colonial a la realidad actual

    Directory of Open Access Journals (Sweden)

    Olegario NEGRÍN FAJARDO

    2012-08-01

    Full Text Available This article has for object indicate, from a perspective historical-educational, what it remains at present in Equatorial Guinea of the educational Spanish influence, specially during the historical pro-Franco period, moment of maximum economic development that it finished with the independence of the colony. For it, first, there are mentioned the characteristics of the educational Spanish model during the colonial epoch and his principal results; secondly, is commented the collapse of the education of European sign by the restoration of the regime of terror of the president Macías Nguema and the later dictatorship of his nephew Teodoro Obiang Nguema; it finishes this contribution indicating the most significant of the current educational panorama of Equatorial Guinea and what stays of the influence of the Spanish education.Con este artículo se da a conocer, desde una perspectiva histórica, qué queda en la actualidad en Guinea Ecuatorial del modelo educativo y cultural impuesto por los españoles en su colonia negro-africana, especialmente durante el período franquista, momento de máximo desarrollo económico que finalizó con la independencia de la colonia. Para ello, en primer lugar, se mencionan las características del modelo educativo español y sus principales resultados; en segundo lugar, se comenta el hundimiento de la educación de signo europeo con la instauración del régimen de terror del presidente Macías Nguema y la posterior dictadura impuesta, después de un golpe de Estado, por su sobrino Teodoro Obiang Nguema; finaliza esta aportación señalando lo más significativo del actual panorama educativo de Guinea Ecuatorial y lo que queda de la influencia de la educación española.

  17. Una aportación al estudio del cuento fang de Guinea Ecuatorial en lengua española / A CONTRIBUTION TO THE STUDY ABOUT THE FANG TALES FROM EQUATORIAL GUINEA IN SPANISH LANGUAGE

    Directory of Open Access Journals (Sweden)

    María Teresa Abaga Envó

    2009-06-01

    la Apertura y Cierre, la unidad argumental, la concentración en un personaje principal, la Ley de la Repetición, la Ley de Tres, la importancia de la posición inicial y final, la Ley de Dos en Escena, la Ley de Contraste y la Ley de Gemelos.Abstract: A revision about the narrative studies shows us that the narrative act is an inherent fact for the human being. “We are homo sapiens, because we are homo narrans”, as the academic José María Merino (2002 has said. Against the narrative structures, the traditional oral tale stands out as the most ancient. So old and so present in all the civilizations that semantic and formal components are repeated in tales from different cultures. Such aspects are the aim of our analysis about this compendium of fairy tales from Equatorial Guinea transmited in Spanish language. In this situation, the oral Fang tales appear like a living art. It is not an event only for children; all the community takes part in this “party” that will be exalted by the presence of the singing. Because there are not many studies about African oral tales (nor about Guinean tales, we compulsorily need to use Western studies, this fact takes us to the field of comparativism. However not always these studies are confirmed in this research which concluded with these results: the viewpoint of truth and fiction disappears (European studies use it to delimit some European traditional stories; the irregular use of formulas at the beginning and in the end; the ludic and the didactic purposes go together in fairy tales; the supposed universalization of the estructuralist method of Vladimir Propp, explained in Morphology of the Tale (1987, seems to be inoperative, because the thirty-one functions are reduced and because its lineal succesion. The themes and the motifs, covered by the spirit of the culture where they appear, are similar to themes and motifs identified in Spanish or International compilations. Finally the oral traditional nature of the

  18. Research on Eddy-eliminating of Equatorial Guinea Djiploho Upstream Regulating Reservoir Bottom Outlet%赤道几内亚吉布洛上游调蓄水库泄洪底孔消涡研究

    Institute of Scientific and Technical Information of China (English)

    王勤香; 王宇

    2016-01-01

    When the bottom outlet of Equatorial Guinea Djiploho upstream regulating reservoir discharging , the intake water surface will appear swirl. In order to eliminate the swirl and improve the intake flow pat-tern, this paper analyzes and verifies the common eddy-eliminating measures through model test. Based on this, combing with the specific situation of engineering, this paper takes into account from the aspects such as construction, operation management and eddy-eliminating effect, it recommends the use of bottom outlet eddy-eliminating measure of head wrapped raised to 620 m overall.%赤道几内亚吉布洛上游调蓄水库底孔泄流时,进口水面出现进气漩涡。为了消除进气漩涡,改善进口流态,通过模型试验对常见的消涡措施进行分析验证。在此基础上,结合工程具体情况,从施工、运行管理及消涡效果等方面进行权衡考虑,推荐采用裹头整体加高到620 m的底孔泄流消涡措施。

  19. Evidence of remote forcing in the Equatorial Atlantic ocean

    OpenAIRE

    Servain, J.; Picaut, Joël; Merle, Jacques

    1982-01-01

    An analysis of sea-surface temperature (STT) and surface winds in selected areas of the Tropical Atlantic indicates that the nonseasonal variability of SST in the Eastern Equatorial Atlantic (Gulf of Guinea) is highly correlated with the nonseasonal variability of the zonal wind stress in the Western Equatorial Atlantic. A negative (positive) anomaly of the zonal wind stress near the North Brazilian coast is followed by a positive (negative) SST anomaly in the Gulf of Guinea about one month l...

  20. The Design of Equatorial Guinea's Parliament Center%地域环境下的建筑创作——赤道几内亚国家议会中心设计

    Institute of Scientific and Technical Information of China (English)

    谢宏杰; 金山; 叶茂

    2013-01-01

    Equatorial Guinea's National Parliament Building is a national multi-functional conference building.As a part of nation's external image,inheritance and regional architectural style is particularly important to show.Based on introducing the design of National Parliament building program,we probe the importance of following the local natural environment,inheriting regional cultural characteristics and creating a new image of regional architecture.We also introduce the program's design ideas and methods.It is hoped as a reference for the creation of new architecture which are respect natural environment and local culture,promote national culture,with a forward-looking spirit in the future.%赤道几内亚国家议会中心是赤道几内亚国家级的多功能会议建筑,作为国家对外形象的一部分,地域性建筑风格的传承与展现尤为重要.该文通过对议会中心建筑方案创作过程和方案的介绍,探讨在地域性建筑设计中顺应地域自然环境、传承地域文化特色、创造地域建筑新形象的重要性以及地域性建筑设计的创作原则、思路与方法.希望以此为引导,为今后尊重地域自然环境、弘扬民族文化特色、具有时空延展性和时代前瞻性的地域性建筑创作提供借鉴.

  1. Three new species of Craterispermum (Rubiaceae) from the Lower Guinea Domain

    OpenAIRE

    Taedoumg, H.; Hamon, P.

    2012-01-01

    Three species of Craterispermum are described from Cameroon, Equatorial Guinea and Gabon. Detailed descriptions and distribution maps are provided for each species, their conservation status is assessed and their taxonomic affinities are discussed. An identification key for the Craterispermum species present in Cameroon, Equatorial Guinea and Gabon is given.

  2. Coastal and Marine Ecosystems-- Equatorial Guinea

    OpenAIRE

    2003-01-01

    Food and Agriculture Organization of the United Nations (FAO),Center for International Earth Science Information Network (CIESIN), World Resources Institute, International Food Policy Research Institute, Global Maritime Boundaries Database (GMBD),World Conservation Monitoring Centre(WCMC),The International Society for Mangrove Ecosystems (ISME)

  3. Current meter components and other data from FIXED PLATFORMS from Gulf of Guinea and other locations as part of the Equatorial Pacific Ocean Climate Studies (EPOCS) and other projects from 08 July 1976 to 01 April 1982 (NODC Accession 9000067)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter components data were collected from FIXED PLATFORMS in the Gulf of Guinea and other locations from 08 July 1976 to 01 April 1982. Data were collected...

  4. Three new species of Craterispermum (Rubiaceae) from the Lower Guinea Domain

    NARCIS (Netherlands)

    Taedoumg, H.; Hamon, P.

    2012-01-01

    Three species of Craterispermum are described from Cameroon, Equatorial Guinea and Gabon. Detailed descriptions and distribution maps are provided for each species, their conservation status is assessed and their taxonomic affinities are discussed. An identification key for the Craterispermum specie

  5. 叠前弹性波阻抗反演技术在赤道几内亚X区块储层预测中的应用%Application of prestack elastic wave impedance inversion technique in reservoir prediction of X block in Equatorial Guinea

    Institute of Scientific and Technical Information of China (English)

    张英德; 陈全红

    2013-01-01

    Water depth of block X in Equatorial Guinea is from 100 to 2000 meter,the problem of looking for deep-water turbidite sandstone reservoir needs to be solved for X block. According to the statistical analysis of the drilled wells,good porosity reservoir can be distinguished by intersection of Vp/Vs and P wave impedance,therefore seismic facies analysis and prestack elastic wave impedance inversion technique were put forward to predict and fine engrave reservoir of prospect A. Reservoir of prospect A has low Vp/Vs, characteristics, and its plane distribution has fan-shaped, and was surmised as deep-water fan turbidite sandstone, which was proved by the drilling well A - 1. The successful application of this method has some reference to West Africa deep-water turbidite sandstone reservoir prediction.%赤道几内亚X区块水深100~2000 m,寻找好的深水浊积砂岩储层是X区块急待解决的一个难题.根据已钻井岩石物理统计分析,基于纵波阻抗与纵横波速度比(Vp/Vs)交汇方式可以有效区分孔隙度较高的砂岩储层,提出了地震相分析结合叠前弹性波阻抗反演技术对区块A目 标储层的发育情况进行了预测和精细刻画,认为A目标具有低纵横波速度比的特征,平面呈扇形分布,推测其为一套深水扇浊积砂岩,后经钻探证实了这一认识.该方法的成功应用对西非深水浊积砂岩储层预测具有一定的借鉴意义.

  6. Intermonsoonal equatorial jets

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.

    Three transects each from the cruises of R V Pioneer (84 , 88 degrees and 92 degrees E) during May-June 1964 and R V Vityaz (77 , 84 degrees and 94 degrees E) during October-November 1962 were used to compare pre and postmonsoon equatorial jets...

  7. Equatorial MST radars: Further consideration

    Science.gov (United States)

    Lagos, P.

    1983-01-01

    The results presented give additional support to the need of equatorial MST radars in order to obtain more information on the nature of equatorial waves in the MST region. Radar deduced winds such as obtained at Jicamarca for periods of months indicate that with these data the full range of equatorial waves, with time scales of seconds to years, can be studied.

  8. Comparative Phylogeography in Rainforest Trees from Lower Guinea, Africa

    OpenAIRE

    Myriam Heuertz; Jérôme Duminil; Gilles Dauby; Vincent Savolainen; Olivier J Hardy

    2014-01-01

    Comparative phylogeography is an effective approach to assess the evolutionary history of biological communities. We used comparative phylogeography in fourteen tree taxa from Lower Guinea (Atlantic Equatorial Africa) to test for congruence with two simple evolutionary scenarios based on physio-climatic features 1) the W-E environmental gradient and 2) the N-S seasonal inversion, which determine climatic and seasonality differences in the region. We sequenced the trnC-ycf6 plastid DNA region ...

  9. Equatorial oceanography. [review of research

    Science.gov (United States)

    Cane, M. A.; Sarachik, E. S.

    1983-01-01

    United States progress in equatorial oceanography is reviewed, focusing on the low frequency response of upper equatorial oceans to forcing by the wind. Variations of thermocline depth, midocean currents, and boundary currents are discussed. The factors which determine sea surface temperature (SST) variability in equatorial oceans are reviewed, and the status of understanding of the most spectacular manifestation of SST variability, the El Nino-Southern Oscillation phenomenon, is discussed. The problem of observing surface winds, regarded as a fundamental factor limiting understanding of the equatorial oceans, is addressed. Finally, an attempt is made to identify those current trends which are expected to bear fruit in the near and distant future.

  10. Homo infantilis: asimilación y segregación en la política colonial española en Guinea Ecuatorial

    OpenAIRE

    Sánchez Molina, Raúl

    2002-01-01

    The otherness' ethnocentric construction such as homo infantilis was used by Europeans to justify colonial policies. Spanish colonial policies in Equatorial Guinea provide us a significant context to analyze this specific colonial image's socio-cultural meanings. This article seeks to understand some of this image's political meanings and functions during the Franco colonial period in Equatorial Guinea. This analysis throws some light upon some colonial policies, such as as...

  11. The seasonal upwellings in the Gulf of Guinea

    Science.gov (United States)

    Verstraete, Jean-Marc

    Observational as well as numerical experiments show that Ekman divergence neither at the equator nor at the coast can explain a significant part of the annual upwelling in the Gulf of Guinea. The remote forcing theory is tested by analyzing both historical data and the FOCAL hydrographic stations (1982-1984). The meteorological data base is analysed as well. Analyses of the thermostad show that waters with the same characteristics as those of the South Atlantic Central Water (SACW) are carried by the equatorial under current (EUC) and the South Equatorial Undercurrent (SEUC) from the western-central equatorial Atlantic at 35° - 29°W towards the thermostad regions in the Gulf of Guinea. The thermostad water is then carried back westward in the two geostrophic compensation flows flanking the EUC at 2° - 3°N and 2° - 3°S. The cooling of the subthermoclinal waters off Abidjan (5°N) and Pointe-Noire (5°S) is related to the advection and vertical spreading of SACW between 500m and 50m in May-June-July. An exceptional warm event occurred in early 1984 in the Gulf of Guinea. The winds collapsed nearly completely all along the equator in January-April 1984. The onset of the African monsoon was late (in July-August 1984), then the monsoon was weaker than climatology in August-October 1984. The equatorial thermocline was observed 50m deeper than climatology in February 1984, then near the surface in July 1984. Sea levels rose over the equatorial Atlantic, the surge reaching about 13cm at 6°E in February 1984, when the western-central equatorial Atlantic was nearly flat. Minimum sea levels occurred in June-July 1984 at 6°E, before the African monsoon. During this event, the maximum speed in the shallow core of the equatorial undercurrent at 4°W and 6°E was nearly insensitive to large changes in the thermal structure (downwelling or upwelling situations). In February-May 1984, we have observed distinct increasing eastward flows at the equator below 250m and minimum

  12. The Equatorial Ekman Layer

    CERN Document Server

    Marcotte, Florence; Soward, Andrew

    2016-01-01

    The steady incompressible viscous flow in the wide gap between spheres rotating about a common axis at slightly different rates (small Ekman number E) has a long and celebrated history. The problem is relevant to the dynamics of geophysical and planetary core flows, for which, in the case of electrically conducting fluids, the possible operation of a dynamo is of considerable interest. A comprehensive asymptotic study, in the limit E<<1, was undertaken by Stewartson (J. Fluid Mech. 1966, vol. 26, pp. 131-144). The mainstream flow, exterior to the E^{1/2} Ekman layers on the inner/outer boundaries and the shear layer on the inner sphere tangent cylinder C, is geostrophic. Stewartson identified a complicated nested layer structure on C, which comprises relatively thick quasi-geostrophic E^{2/7} (inside C) and E^{1/4} (outside C) layers. They embed a thinner E^{1/3} ageostrophic shear layer (on C), which merges with the inner sphere Ekman layer to form the E^{2/5} Equatorial Ekman layer of axial length E^{...

  13. Guinea-Bissau.

    Science.gov (United States)

    1989-02-01

    Guinea-Bissau is a small country on the west coast of Africa, bounded on the north by Senegal and on the south and east by Guinea. Most of the coastal area and the lowland along the rivers is covered by palm trees and mangrove thickets; a transitional zone of hardwood gives way to the tree-covered grasslands of the interior. The country's population is composed of several diverse tribal groups, each with its own language and customs. A former Portuguese colony, Guinea-Bissau was granted independence in 1974 after a 13-year revolutionary struggle. Today it is a 1-party state headed by Joao Bernardo Vieira--chief executive, head of party, and commander in chief of the armed forces. Among the world's least developed countries, the chief economic activity in Guinea-Bissau is agriculture. Rice is the major crop and staple food, but production has been insufficient to satisfy local needs. Small amounts of peanuts, cashews, palm kernels, and timber are exported, along with some fish and seafood. As part of an economic reform program, the government is privatizing para-statal organizations, paying higher prices to farmers as an incentive for increased production, and encouraging the entrepreneurs to exploit the country's resources. Guinea-Bissau follows a foreign policy of nonalignment, maintaining good relations with communist as well as noncommunist states. PMID:12178000

  14. PMP-2: Equatorial wave dynamics

    Science.gov (United States)

    Hirota, I.

    1982-01-01

    After the discovery of the quasi-biennial oscillation (QBO) in the stratospheric zonal wind, there were, in the last two decades, a large number of observational and theoretical studies on the structure and behavior of the mean zonal wind and waves in the tropical stratosphere. Planetary-scale, vertically propagating equatorial waves play an important role in producing the QBO through the mechanism of wave-mean flow interaction. Concerning the dynamics of the equatorial upper stratosphere and mesosphere, however, little was known about the possible wave motions, except for tides, mainly because of the lack of adequate observations in this region. The main purpose is to provide the nature of various types of equatorial wave modes, with the aid of improved sounding techniques and sophisticated numerical modelings.

  15. Guinea pig maximization test

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner

    1985-01-01

    Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline...

  16. The guinea-pig

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Maibach, H I; Anjo, M D

    1980-01-01

    14C ring-labelled hydrocortisone, testosterone and benzoic acid dissolved in acetone were applied to the backs of guinea-pigs (4 microgram/cm2). Percutaneous absorption was quantified by following the excretion of tracer in urine and faeces for 5 days. Absorption of hydrocortisone and benzoic acid...... was 2.4% (s.d. = 0.5; n = 3) and 31.4% (s.d. = 9.1; n = 3) of the applied dose respectively, similar to published human absorption data. Testosterone was absorbed to a greater extent in guinea-pigs (34.9% +/- 5.4; n = 5) than man. A thioglycollate based depilatory cream significantly increased the...

  17. Guinea Fowl Production in Botswana

    Directory of Open Access Journals (Sweden)

    John Cassius Moreki

    2012-03-01

    Full Text Available Guinea fowl farming is still in its infancy in Botswana; hence the population of farmed guinea fowl is unknown, as well as, their contribution to human nutrition. Presently, production occurs mainly at subsistence level and females (women appear to dominate the industry. In Botswana, guinea fowl are raised mainly under the semi-intensive system. Guinea fowl meat is of high quality, being high in protein and low in fat content, thus it is highly prized compared to chicken meat. It appears that guinea fowl farming could be more suitable to the rural areas where commercial chicken production has failed because guinea fowl are tolerant to diseases than chickens. Some challenges to guinea fowl production include farmers’ inadequate management skills necessary to raise guinea fowl successfully, inadequate technical support and lack of financial support from government extension services. It appears that guinea fowl production could be an important supplier of high quality animal protein (meat and eggs, as well as, a job creator in the rural areas.

  18. Papua New Guinea.

    Science.gov (United States)

    1989-07-01

    The eastern half of the island of New Guinea (85% of total area); the Bismarck, Trobriand, Louisiade, and D'Entrecasteaux Archipelagos; and Bougainville, Buka, and Woodlark islands constitute the predominantly mountainous country of Papua New Guinea. It is located 160 km northeast of Australia in the South Pacific Ocean. This tropical country has 2 monsoon seasons with average annual rainfall ranging from 200-250 cm. It has 1 of the most heterogenous populations in the world with as many as several 1000 separate communities. Only 650 languages have yet been identified with 160 of them totally unrelated to each other or to any other language. At different times in its history, the country (or parts thereof) has been under the control of Germany, Australia (its largest bilateral aid donor), Japan, and Britain. After independence in 1975, Papua New Guinea established a veritable and strong parliamentary democracy. This democracy has an excellent human rights record and has a clear respect for these rights. 75% of the population live predominately at subsistence level. Gross domestic product (GDP) increased about 2%/year during the 1980s with agriculture making up 35% of GDP (40% of exports) and mining (copper and gold) 15%. In 1989, exports included 40% of GDP. Other than mining, the industrial sector made up 9% of GDP with little contributing to exports. Food processing was the fastest growing segment of the industrial segment. 45% of agricultural production consisted of subsistence cultivation. Coffee and cocoa were the 2 leading cash crops. Financially, the country was sound in 1989 with exports and imports almost equal from 1986. The United States relationship with Papua New Guinea is friendly and the 2 countries have a good trade relationship.

  19. Papua New Guinea.

    Science.gov (United States)

    1986-10-01

    The situation of the island archipelago nation of Papua New Guinea is reviewed in terms of its geography, people, history, government, politics economy and foreign relations. Papua New Guinea consists of the eastern half of the main island of New Guinea (the western portion is Indonesia), and several island groups, all located northeast of Australia. The island has extreme geographical variations, ranging from precipitous mountains to extensive swamps and river valleys, all in a monsoon cimate. As a result, there are hundreds of small groups each with unique cultures and languages; over 650 languages, many unrelated to each other. The population is estimated at 3.5 million, growing at about 2.5% per year. Historically, the region has been occupied by Germany, Britain, Japan, and the U.S. The country came under the international trusteeship system in 1949, and now has a vigorous parliamentary government. The economy is based on subsistence agriculture, but is buttressed by resources such as gold, copper, and other metals, oil, timber, tropical agricultural products, fish. The only indusry is local production, since the minimum wage is too high to compete with Asian labor. PMID:12177935

  20. Estudio de productos forestales no maderables en tres mercados de Guinea Ecuatorial

    Directory of Open Access Journals (Sweden)

    Obama Ondo, Crisantos

    2001-12-01

    Full Text Available The presence of vegetable oils, wild fruits, spices, medicinal plants, plant stimulants and melongos in the markets of Ebibeyín, Bata and Malabo of Equatorial-Guinea have been studied, as remarkable non-wood forest products from these markets. The possible impact of the uses of these products on the natural environments are discussed. Some suggestions about the improvement and development of the non-wood forest products in Equatorial-Guinea are given.Se han tomado datos en los mercados de Ebibeyín, Bata y Malabo, en Guinea Ecuatorial, sobre aceites vegetales, frutos silvestres comestibles, condimentos de origen vegetal, plantas medicinales, plantas estimulantes y melongos, como principales productos forestales no maderables en venta en dichos mercados. Se discuten cuestiones generales relacionadas con el medio natural y el posible impacto en él del uso de estos productos. El estudio finaliza con unas sugerencias sobre temas relativos a la mejora y desarrollo del sector de los productos forestales no maderables en Guinea Ecuatorial.

  1. A new afrotropical species of Ormyrus Westwood, 1832 (Hymenoptera, Chalcidoidea, Ormyridae

    Directory of Open Access Journals (Sweden)

    Gómez, J. F.

    2007-06-01

    Full Text Available Anew species, Ormyrus fernandinus sp. n. (Hymenoptera, Chalcidoidea, Ormyridae, is described from the island of Bioko (Equatorial Guinea. Collected with Malaise trap, the biology of the new species is unknown. The differential morphological features of the new species with respect to known afrotropical Ormyrus species, and its phylogenetic relationships are discussed.Se describe una nueva especie, Ormyrus fernandinus sp. n. (Hymenoptera, Chalcidoidea, Ormyridae, de la isla de Bioko (Guinea Ecuatorial. La especie fue colectada con trampa Malaise por lo que se desconoce su biología. Se discuten los caracteres distintivos fundamentales de la nueva especie en relación a las especies de Ormyrus conocidas en la region Afrotropical, y sus relaciones filogenéticas.

  2. Petroleum service projects in the Gulf of Guinea

    Science.gov (United States)

    Ken-Worgu, Kenneth Chukwumeka

    2011-07-01

    The goal of this record of study is to examine the major facets involved in managing several petroleum service projects located in three different countries in the Gulf of Guinea simultaneously, while effectively engaging in business development activities for the Oil and Industrial Services Group (OIS). This work also furnishes adequate background on related subject matters to enable understanding of the projects presented. The petroleum services sector is the back bone of the oil and gas industry. Services companies are vital to the success of all petroleum and energy producers in the USA, the Gulf of Guinea and the world. There is a need and demand for these service companies because they play various roles such as logistics, drilling, construction, dredging, pipe laying, procurement, food supply, human resource supply, etc. The Gulf of Guinea comprises of countries from west and central Africa. This project was limited to Nigeria, Equatorial Guinea and Cameroon. This area holds the largest petroleum reserves in Africa and plays a vital role in the global supply of petroleum. The Oil and Industrial Services Group (OIS), plans to establish herself as one of the leading petroleum service companies in this gulf. To manage this expansion, I have taken the role of Gulf of Guinea manager to apply my background as a petroleum engineer as well as my business skills to build a successful division of the company. This work provides a record of study of the management of services, projects and contracts carried out by the OIS group in the gulf of Guinea. The following are the specific projects in the Gulf of Guinea that I participated in: Managing delivering, maintenance and marketing of offshore vessels, Offshore pipe laying project, Integrated pipeline maintenance project, Development a petroleum technical training facilities, Agbami pipe insulation project, Engineering lift project and Capital budgeting analysis for potential investments. The details of the specific

  3. Benthic foraminifera from the deep-water Niger delta (Gulf of Guinea): Assessing present-day and past activity of hydrate pockmarks

    NARCIS (Netherlands)

    Fontanier, C.; Koho, K.A.; Goñi-Urriza, M.S.; Deflandre, B.; Galaup, S.; Ivanovsky, A.; Gayet, N.; Dennielou, B.; Gremare, A.; Bichon, S.; Gassie, C.; Anschutz, P.; Durán, R.; Reichart, G.J.

    2014-01-01

    We present ecological and isotopic (d18O and d13C) data on benthic foraminifera sampled from 4 deep-sea stations in a pockmark field from the deep-water Niger delta (Gulf of Guinea, Equatorial Atlantic Ocean). In addition, a series of sedimentological and (bio)geochemical data are shown to back up f

  4. Benthic foraminifera from the deep-water Niger delta (Gulf of Guinea) : Assessing present-day and past activity of hydrate pockmarks

    NARCIS (Netherlands)

    Fontanier, C.; Koho, K. A.; Goñi-Urriza, M. S.; Deflandre, B.; Galaup, S.; Ivanovsky, A.; Gayet, N.; Dennielou, B.; Grémare, A.; Bichon, S.; Gassie, C.; Anschutz, P.; Duran, R.; Reichart, G. J.

    2014-01-01

    We present ecological and isotopic (δ18O and δ13C) data on benthic foraminifera sampled from 4 deep-sea stations in a pockmark field from the deep-water Niger delta (Gulf of Guinea, Equatorial Atlantic Ocean). In addition, a series of sedimentological and (bio)geochemical data are shown to back up f

  5. Optimal Broadcasting of Mixed Equatorial Qubits

    Institute of Scientific and Technical Information of China (English)

    YU Zong-Wen

    2009-01-01

    We derive an optimal 2→M phase-covariant quantum broadcasting of mixed equatorial qubits.This quantum broadcasting is optimal in the sense that the shrinking factor between the input and the output single qubit achieves the upper bound.The result shows that we can copy two identical mixed equatorial qubits with the same quality as those of two identical pure equatorial states.

  6. Aerosol Transport Over Equatorial Africa

    Science.gov (United States)

    Gatebe, C. K.; Tyson, P. D.; Annegarn, H. J.; Kinyua, A. M.; Piketh, S.; King, M.; Helas, G.

    1999-01-01

    Long-range and inter-hemispheric transport of atmospheric aerosols over equatorial Africa has received little attention so far. Most aerosol studies in the region have focussed on emissions from rain forest and savanna (both natural and biomass burning) and were carried out in the framework of programs such as DECAFE (Dynamique et Chimie Atmospherique en Foret Equatoriale) and FOS (Fires of Savanna). Considering the importance of this topic, aerosols samples were measured in different seasons at 4420 meters on Mt Kenya and on the equator. The study is based on continuous aerosol sampling on a two stage (fine and coarse) streaker sampler and elemental analysis by Particle Induced X-ray Emission. Continuous samples were collected for two seasons coinciding with late austral winter and early austral spring of 1997 and austral summer of 1998. Source area identification is by trajectory analysis and sources types by statistical techniques. Major meridional transports of material are observed with fine-fraction silicon (31 to 68 %) in aeolian dust and anthropogenic sulfur (9 to 18 %) being the major constituents of the total aerosol loading for the two seasons. Marine aerosol chlorine (4 to 6 %), potassium (3 to 5 %) and iron (1 to 2 %) make up the important components of the total material transport over Kenya. Minimum sulfur fluxes are associated with recirculation of sulfur-free air over equatorial Africa, while maximum sulfur concentrations are observed following passage over the industrial heartland of South Africa or transport over the Zambian/Congo Copperbelt. Chlorine is advected from the ocean and is accompanied by aeolian dust recirculating back to land from mid-oceanic regions. Biomass burning products are transported from the horn of Africa. Mineral dust from the Sahara is transported towards the Far East and then transported back within equatorial easterlies to Mt Kenya. This was observed during austral summer and coincided with the dying phase of 1997/98 El

  7. Radio wave scintillations at equatorial regions

    Science.gov (United States)

    Poularikas, A. D.

    1972-01-01

    Radio waves, passing through the atmosphere, experience amplitude and phase fluctuations know as scintillations. A characterization of equatorial scintillation, which has resulted from studies of data recorded primarily in South America and equatorial Africa, is presented. Equatorial scintillation phenomena are complex because they appear to vary with time of day (pre-and postmidnight), season (equinoxes), and magnetic activity. A wider and more systematic geographical coverage is needed for both scientific and engineering purposes; therefore, it is recommended that more observations should be made at earth stations (at low-geomagnetic latitudes) to record equatorial scintillation phenomena.

  8. Central Equatorial Pacific Experiment (CEPEX)

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    The Earth's climate has varied significantly in the past, yet climate records reveal that in the tropics, sea surface temperatures seem to have been remarkably stable, varying by less than a few degrees Celsius over geologic time. Today, the large warm pool of the western Pacific shows similar characteristics. Its surface temperature always exceeds 27[degree]C, but never 31[degree]C. Heightened interest in this observation has been stimulated by questions of global climate change and the exploration of stabilizing climate feedback processes. Efforts to understand the observed weak sensitivity of tropical sea surface temperatures to climate forcing has led to a number of competing ideas about the nature of this apparent thermostat. Although there remains disagreement on the processes that regulate tropical sea surface temperature, most agree that further progress in resolving these differences requires comprehensive field observations of three-dimensional water vapor concentrations, solar and infrared radiative fluxes, surface fluxes of heat and water vapor, and cloud microphysical properties. This document describes the Central Equatorial Pacific Experiment (CEPEX) plan to collect such observations over the central equatorial Pacific Ocean during March of 1993.

  9. Hydroclimatogical Changes and Impacts on Seasonal Regimes of African Equatorial Rivers

    Science.gov (United States)

    Mahe, G. M.

    2015-12-01

    In recent decades, changes in the pattern of hydroclimatogical cycle have been observed with impacts on seasonal regimes of African equatorial rivers. This communication reports on studies carried out for a set of river basins in equatorial Africa, tributaries of the Atlantic Gulf of Guinea: the Ogooue River in Gabon, the Kouilou River in Congo, and the basins of South Cameroon. These rivers are compared to the Congo River. A new monthly gridded rainfall dataset, and streamflow from selected rivers where used in the analysis. The observed changes include changes in seasonal pattern of rainfall and changes in monthly streamflow regimes. The study shows a decrease of rainfall in the southern hemisphere during February to May since the end of the 80s, while the decrease is much more limited in the Northern hemisphere. For the equatorial rivers, the March-June flood decreased steadily between the 70s and 80s, in correlation with a slight decrease of the rainfall between March and June, while the October-December flood showed no change. This trend was confirmed during the 2000s for the Ogooue River from updated times series, including a shift of the maximum in April instead of May. Locally, the dry season (July-September) disappeared on the coastal basin of the Kienke River at Kribi in Cameroon. It seems that these two months of July and August have become part of a 'single' large rainy season instead of separating the former two rainy seasons. A slight decrease in seasonal rainfall together with a small change in the intra-seasonal rainfall distribution, most probably led to one of the biggest change in hydrological regimes in Equatorial Africa, which could be a clue to understanding climate change in the region. This rainfall change is different for the Congo River which large basins integrates various climatic forcings.

  10. Papua New Guinea Student Assesment

    OpenAIRE

    World Bank Group

    2014-01-01

    This report focuses specifically on policies in the area of student assessment. Papua New Guinea has focused on increasing student learning outcomes by improving the quality of education in the country. An effective student assessment system is an important component of efforts to improve education quality and learningoutcomes because it provides the necessary information to meet stakehold...

  11. Equatorially coordinated lanthanide single ion magnets.

    Science.gov (United States)

    Zhang, Peng; Zhang, Li; Wang, Chao; Xue, Shufang; Lin, Shuang-Yan; Tang, Jinkui

    2014-03-26

    The magnetic relaxation dynamics of low-coordinate Dy(III) and Er(III) complexes, namely three-coordinate ones with an equatorially coordinated triangle geometry and five-coordinate ones with a trigonal bipyramidal geometry, have been exploited for the first time. The three-coordinate Er-based complex is the first equatorially coordinated mononuclear Er-based single-molecule magnet (SMM) corroborating that simple models can effectively direct the design of target SMMs incorporating 4f-elements. PMID:24625001

  12. Alternative Poultry Breeding: Guinea Fowl Breeding

    Directory of Open Access Journals (Sweden)

    Sezai Alkan

    2015-10-01

    Full Text Available Guinea fowl live on the Africa continent as wild and where used intensively family livestock farming in the rural. Although the homeland of the Africa continent, Guinea growing rapidly increasing in the World. Nowadays, Guinea fowl is an important alternative genetic resource can be used in organic livestock farming which developing quickly. Able to adapt to different climatic conditions, have an economic efficiency level in the don’t good environmental conditions and being resistant to diseases are the biggest advantages. Besides, Guinea fowl eats insects, ticks, worms, mouse and snakes, especially in the surrounding of the livestock farming in the rural it can be used for biological control of these pests easily. Because of these advantages, Guinea fowl has a potential for alternative poultry production in Turkey. In this review, importance and general characteristics of Guinea fowl are given.

  13. Mesozoic Source-to-Sink of the African margin of the Equatorial Atlantic

    Science.gov (United States)

    ye, jing; Chardon, Dominique; rouby, delphine; Guillocheau, François; Robin, Cecile; Loparev, Artiom; Huyghe, damien; Dall'Asta, Massimo; Brown, Roderick; wildman, mark; webster, david

    2016-04-01

    The objective of the Transform Source to Sink Project (TS2P) is to link the dynamics of the erosion of the West African Craton to the offshore sedimentary basins of the African margin of the Equatorial Atlantic at geological time scales. This margin, alternating transform and oblique segments from Guinea to Nigeria, shows a strong structural variability in the margin width, continental geology and relief, drainage networks and subsidence/accumulation patterns. We analyzed this system combining onshore geology and geomorphology as well as offshore sub-surface data. We produced paleogeographic maps at the scale of West Africa spanning the continental domain and offshore basins since 200 Ma. Mapping spatial and temporal distribution of domains either in erosion (sources) or in accumulation (sinks) document the impact of the successive rifting of Central and Equatorial Atlantic on the physiography of the area. We use low temperature thermochronology dating along three transects perpendicular to the margin (Guinea, Ivory Coast and Benin) to determine periods and domains of denudation in that framework. We compare these data to the Mesozoic accumulation histories in passive margin basins and discuss their stratigraphic expression according to the type of margin segment they are preserved in. Syn-rift architectures (Early Cretaceous) are largely impacted by transform faults that define sub-basins with contrasted width of crustal necking zone (narrower in transform segments than in oblique/normal segments). During the Late Cretaceous post-rift, sedimentary wedges record a transgression along the all margin. Proximal parts of the sedimentary wedge are preserved in basins developing on segments with wide crustal necking zone while they were eroded away in basins developing on narrow segments. As a difference, the Cenozoic wedge is everywhere preserved across the whole width of the margin.

  14. Guinea pig model of tuberculosis

    Institute of Scientific and Technical Information of China (English)

    Pushpa Gupta; U.D.Gupta

    2009-01-01

    Animal models are being developed for testing different vaccine candidates as well as testing of new antituber-cular since a long time.Mice,guinea pigs and rabbits are animals which are frequently used.Though each model has got its merits as well as demerits and each of them differ from human tuberculosis in one aspect or the other but none of the model completely mimics the human disease.Out of the different animal species, guinea pig model is one of the better models as it is very sensitive to M.tuberculosis infection but it has certain limitations like paucity of immunological reagents.However,it is the best model for tuberculosis research.

  15. Variability in equatorial foF2

    International Nuclear Information System (INIS)

    Investigation on the variability of foF2 at an equatorial station in the African continent was undertaken. The analysis included diurnal, seasonal and solar cycle effects on both absolute and relative variability. The trends in the behavior of absolute variability are different from those of relative variability. (author)

  16. Variability of TEC over an equatorial station

    International Nuclear Information System (INIS)

    Variability in TEC obtained by the Faraday rotation technique at an equatorial station is investigated. Diurnal, seasonal and solar cycle effects were observed. Both absolute and relative variability were considered. The trend of variations in absolute variability is completely different from those of relative variability. (author)

  17. Coccolithophores in the equatorial Atlantic Ocean

    DEFF Research Database (Denmark)

    Kinkel, Hanno; Baumann, K.-H.; Cepek, M.

    2000-01-01

    The present study was initiated to ascertain the significance of coccolithophores as a proxy for paleoceanographic and paleoproductivity studies in the equatorial Atlantic. Data from a range of different samples, from the plankton, surface sediments as well as sediment cores are shown and compare...

  18. PMP-2 Report: Equatorial Wave Dynamics

    Science.gov (United States)

    Hirota, I.

    1982-01-01

    The activities of the pre-MAP project 2 (PMP-2) from 1978 through 1981 are described. The following topics relating to the equatorial middle atmosphere are discussed briefly: (1) the semi-annual oscillation and Kelvin waves; (2) planetary Rossby waves; (3) upper mesospheric waves; and (4) gravity waves.

  19. Equatorial scintillations: advances since ISEA-6

    Science.gov (United States)

    Basu, Sunanda; Basu, Santimay

    1985-10-01

    Since the last equatorial aeronomy meeting in 1980, our understanding of the morphology of equatorial scintillations has advanced greatly due to more intensive observations at the equatorial anomaly locations in the different longitude zones. The unmistakable effect of the sunspot cycle in controlling irregularity belt width and electron concentration responsible for strong scintillation in the GHz range has been demonstrated. The fact that night-time F-region dynamics is an important factor in controlling the magnitude of scintillations has been recognized by interpreting scintillation observations in the light of realistic models of total electron content at various longitudes. A hypothesis based on the alignment of the solar terminator with the geomagnetic flux tubes as an indicator of enhanced scintillation occurrence and another based on the influence of a transequatorial thermospheric neutral wind have been postulated to describe the observed longitudinal variation. A distinct class of equatorial irregularities known as the bottomside sinusoidal (BSS) type has been identified. Unlike equatorial bubbles, these irregularities occur in very large patches, sometimes in excess of several thousand kilometers in the E-W direction and are associated with frequency spread on ionograms. Scintillations caused by such irregularities exist only in the VHF band, exhibit Fresnel oscillations in intensity spectra and are found to give rise to extremely long durations (~ several hours) of uninterrupted scintillations. These irregularities maximize during solstices, so that in the VHF range, scintillation morphology at an equatorial station is determined by considering occurrence characteristics of both bubble type and BSS type irregularities. The temporal structure of scintillations in relation to the in situ measurements of irregularity spatial structure within equatorial bubbles has been critically examined. A two-component irregularity spectrum with a shallow slope ( p1

  20. Comparative phylogeography in rainforest trees from Lower Guinea, Africa.

    Science.gov (United States)

    Heuertz, Myriam; Duminil, Jérôme; Dauby, Gilles; Savolainen, Vincent; Hardy, Olivier J

    2014-01-01

    Comparative phylogeography is an effective approach to assess the evolutionary history of biological communities. We used comparative phylogeography in fourteen tree taxa from Lower Guinea (Atlantic Equatorial Africa) to test for congruence with two simple evolutionary scenarios based on physio-climatic features 1) the W-E environmental gradient and 2) the N-S seasonal inversion, which determine climatic and seasonality differences in the region. We sequenced the trnC-ycf6 plastid DNA region using a dual sampling strategy: fourteen taxa with small sample sizes (dataset 1, mean n = 16/taxon), to assess whether a strong general pattern of allele endemism and genetic differentiation emerged; and four taxonomically well-studied species with larger sample sizes (dataset 2, mean n = 109/species) to detect the presence of particular shared phylogeographic patterns. When grouping the samples into two alternative sets of two populations, W and E, vs. N and S, neither dataset exhibited a strong pattern of allelic endemism, suggesting that none of the considered regions consistently harboured older populations. Differentiation in dataset 1 was similarly strong between W and E as between N and S, with 3-5 significant F ST tests out of 14 tests in each scenario. Coalescent simulations indicated that, given the power of the data, this result probably reflects idiosyncratic histories of the taxa, or a weak common differentiation pattern (possibly with population substructure) undetectable across taxa in dataset 1. Dataset 2 identified a common genetic break separating the northern and southern populations of Greenwayodendron suaveolens subsp. suaveolens var. suaveolens, Milicia excelsa, Symphonia globulifera and Trichoscypha acuminata in Lower Guinea, in agreement with differentiation across the N-S seasonal inversion. Our work suggests that currently recognized tree taxa or suspected species complexes can contain strongly differentiated genetic lineages, which could lead

  1. Comparative phylogeography in rainforest trees from Lower Guinea, Africa.

    Directory of Open Access Journals (Sweden)

    Myriam Heuertz

    Full Text Available Comparative phylogeography is an effective approach to assess the evolutionary history of biological communities. We used comparative phylogeography in fourteen tree taxa from Lower Guinea (Atlantic Equatorial Africa to test for congruence with two simple evolutionary scenarios based on physio-climatic features 1 the W-E environmental gradient and 2 the N-S seasonal inversion, which determine climatic and seasonality differences in the region. We sequenced the trnC-ycf6 plastid DNA region using a dual sampling strategy: fourteen taxa with small sample sizes (dataset 1, mean n = 16/taxon, to assess whether a strong general pattern of allele endemism and genetic differentiation emerged; and four taxonomically well-studied species with larger sample sizes (dataset 2, mean n = 109/species to detect the presence of particular shared phylogeographic patterns. When grouping the samples into two alternative sets of two populations, W and E, vs. N and S, neither dataset exhibited a strong pattern of allelic endemism, suggesting that none of the considered regions consistently harboured older populations. Differentiation in dataset 1 was similarly strong between W and E as between N and S, with 3-5 significant F ST tests out of 14 tests in each scenario. Coalescent simulations indicated that, given the power of the data, this result probably reflects idiosyncratic histories of the taxa, or a weak common differentiation pattern (possibly with population substructure undetectable across taxa in dataset 1. Dataset 2 identified a common genetic break separating the northern and southern populations of Greenwayodendron suaveolens subsp. suaveolens var. suaveolens, Milicia excelsa, Symphonia globulifera and Trichoscypha acuminata in Lower Guinea, in agreement with differentiation across the N-S seasonal inversion. Our work suggests that currently recognized tree taxa or suspected species complexes can contain strongly differentiated genetic lineages

  2. Deep currents in the Gulf of Guinea: along slope propagation of intraseasonal waves

    Directory of Open Access Journals (Sweden)

    C. Guiavarc'h

    2009-05-01

    Full Text Available In the Gulf of Guinea, intraseasonal variability is large at the equator and along the coast. Current data on the continental slope near 7.5° S show very energetic biweekly oscillations at 1300 m depth. A high resolution primitive equation numerical model demonstrates that this deep variability is forced by equatorial winds, through the generation of equatorial Yanai waves that propagate eastward and at depth, and then poleward as coastally-trapped waves upon reaching the coast of Africa. Intraseasonal variability is intensified along the coast of the Gulf of Guinea, especially in the 10–20 day period range and at depths between 500 and 1500 m. The kinetic energy distribution is well explained at first order by linear theory. Along the equator, eastward intensification of energy and bottom intensification are in qualitative agreement with vertically propagating Yanai waves, although the signal is influenced by the details of the bathymetry. Along the coast, baroclinic modes 3 to 5 are important close to the equator, and the signal is dominated by lower vertical modes farther south. Additional current meter data on the continental slope near 3° N display an energy profile in the 10–20 day period band that is strikingly different from the one at 7.5° S, with surface intensification rather than bottom intensification and a secondary maximum near 800 m. The model reproduces these features and explains them: the surface intensification in the north is due to the regional wind forcing, and the north-south asymmetry of the deep signal is due to the presence of the zonal African coast near 5° N. A 4 years time series of current measurements at 7.5° S shows that the biweekly oscillations are intermittent and vary from year to year. This intermittency is not well correlated with fluctuations of the equatorial winds and does not seem to be a simple linear response to the wind forcing.

  3. Severe allergic reactions to guinea pig

    Directory of Open Access Journals (Sweden)

    Shaw Jeffrey L

    2005-10-01

    Full Text Available Abstract Background Allergic sensitization and reactions to guinea pig (Cavia porcellus have been well documented in laboratory animal handlers, primarily manifesting as rhinitis, conjunctivitis, and asthma. Severe allergic reactions, however, are rare. Methods We report two patients with severe allergic reactions following non-occupational exposure to guinea pigs. The first patient, an 11-year-old female, developed ocular, nasal, skin and laryngeal edema symptoms immediately after handling a guinea pig. The second patient, a 24-year-old female, developed symptoms of isolated laryngeal edema after cleaning a guinea pig cage. Percutaneous skin testing, RAST, ELISA and ELISA inhibition testing with guinea pig extract were performed. Results Both patients had IgE-mediated allergy to guinea pig confirmed by ELISA and either RAST or skin testing. ELISA inhibition studies confirmed the specificity of the IgE reactivity to guinea pig. Conclusion Severe IgE-mediated reactions can occur following non-occupational guinea pig exposure. Physicians should be aware of this possibility.

  4. Clausiliidae (Gastropoda, Pulmonata) from western New Guinea

    NARCIS (Netherlands)

    Loosjes, F.E.

    1956-01-01

    During the zoological exploration of Netherlands New Guinea sponsored by the Rijksmuseum van Natuurlijke Historie, Leiden, in 1954-1955, four specimens of Clausiliidae were found. There are no previous records of the occurrence of Clausiliidae in New Guinea; the most eastern locality in the Indo-Aus

  5. Observational features of equatorial coronal hole jets

    OpenAIRE

    Nisticò, G.; V. Bothmer; S. Patsourakos; Zimbardo, G.

    2010-01-01

    Collimated ejections of plasma called "coronal hole jets" are commonly observed in polar coronal holes. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. In this paper we present some observations of "equatorial coronal hole jets" made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and December 2007. The jet e...

  6. Sunrise enhancement of equatorial vertical plasma drift

    Science.gov (United States)

    Liu, Libo; Zhang, Ruilong; Le, Huijun

    2016-04-01

    Sunrise enhancement in vertical plasma drift over equatorial regions is not discernible in the statistical picture compared with the significant enhancement during dusk hours. In this report, it is the first time to investigate the occurrence of the dawn enhancement in the equatorial ionospheric vertical plasma drift from ROCSAT-1 observations during geomagnetic quiet times. The dawn enhancements occur most frequently in June solstice and least frequently in December solstice. The statistical survey shows that the occurrence depends on the magnetic declination. The enhancement has the strongest amplitude in regions near 320° longitude and peaks during June solstice. The dawn enhancement reaches its peak after the sunrise in conjugated E regions. Furthermore, it is found that the dawn enhancement is closely related to the difference between the sunrise times in the conjugated E regions (sunrise time lag). The dawn enhancement occurs easily in regions with a large sunrise time lag. Moreover, we will report the effects of the sunrise enhancement of vertical plasma drift on the equatorial ionosphere as indicated from the observations and model simulations. We thanks National Central University of Taiwan providing the ROCSAT-1 data. The Ap and F107 indices are obtained from the National Geophysical Data Center (http://spidr.ngdc.noaa.gov/spidr/). This research is supported by National Natural Science Foundation of China (41231065), the Chinese Academy of Sciences project (KZZD-EW-01-3), National Key Basic Research Program of China (2012CB825604) and National Natural Science Foundation of China (41321003).

  7. Prolactin Family of the Guinea Pig, Cavia porcellus

    OpenAIRE

    Alam, S.M. Khorshed; Konno, Toshihiro; Rumi, M. A. Karim; Dong, Yafeng; Weiner, Carl P.; Soares, Michael J.

    2010-01-01

    Prolactin (PRL) is a multifunctional hormone with prominent roles in regulating growth and reproduction. The guinea pig (Cavia porcellus) has been extensively used in endocrine and reproduction research. Thus far, the PRL cDNA and protein have not been isolated from the guinea pig. In the present study, we used information derived from the public guinea pig genome database as a tool for identifying guinea pig PRL and PRL-related proteins. Guinea pig PRL exhibits prominent nucleotide and amino...

  8. Guinea-pig breeding for meat production

    OpenAIRE

    Aguilera Hidalgo, Grey Estefanía

    2013-01-01

    Guinea-pig breeding for meat production is one of the unknown economical activities in the Czech Republic and in many other contries in the world. It is an industry that is developing fast in Ecuador, Peru, Bolivia and Colombia, because of fact that it is easy, fast and it does not need a lot of investment and where its consumption averages 20 to 65 milion guinea-pigs per year. The main objective of guinea-pig breeding just like breeding of other livestock, is to produce big amounts of meat w...

  9. Papua New Guinea Tsunami, July 17, 1998

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On the evening of Friday July 17, 1998, a magnitude Ms 7.1 earthquake occurred near the northwest coast Papua New Guinea 850 km (510 miles ) northwest of Port...

  10. MACSAT - A Near Equatorial Earth Observation Mission

    Science.gov (United States)

    Kim, B. J.; Park, S.; Kim, E.-E.; Park, W.; Chang, H.; Seon, J.

    MACSAT mission was initiated by Malaysia to launch a high-resolution remote sensing satellite into Near Equatorial Orbit (NEO). Due to its geographical location, Malaysia can have large benefits from NEO satellite operation. From the baseline circular orbit of 685 km altitude with 7 degrees of inclination, the neighboring regions around Malaysian territory can be frequently monitored. The equatorial environment around the globe can also be regularly observed with unique revisit characteristics. The primary mission objective of MACSAT program is to develop and validate technologies for a near equatorial orbit remote sensing satellite system. MACSAT is optimally designed to accommodate an electro-optic Earth observation payload, Medium-sized Aperture Camera (MAC). Malaysian and Korean joint engineering teams are formed for the effective implementation of the satellite system. An integrated team approach is adopted for the joint development for MACSAT. MAC is a pushbroom type camera with 2.5 m of Ground Sampling Distance (GSD) in panchromatic band and 5 m of GSD in four multi-spectral bands. The satellite platform is a mini-class satellite. Including MAC payload, the satellite weighs under 200 kg. Spacecraft bus is designed optimally to support payload operations during 3 years of mission life. The payload has 20 km of swath width with +/- 30 o of tilting capability. 32 Gbits of solid state recorder is implemented as the mass image storage. The ground element is an integrated ground station for mission control and payload operation. It is equipped with S- band up/down link for commanding and telemetry reception as well as 30 Mbps class X-band down link for image reception and processing. The MACSAT system is capable of generating 1:25,000-scale image maps. It is also anticipated to have capability for cross-track stereo imaging for Digital elevation Model (DEM) generation.

  11. Analysis of the Day Side Equatorial Anomaly

    OpenAIRE

    Shankar, Jayaprabha

    2007-01-01

    Equatorial Ionization Anomaly (EIA) is a region of peak plasma density found at ± 10 ◦ to 20 ◦ magnetic latitudes at F-region altitudes. In 2002, NASA launched the Global Ultra Violet Imager (GUVI), which can observe the EIA at various local times, longitudes, and seasons by the glow of the recombining electrons and ions in the plasma. This thesis presents the observations of the geomagnetic quiet time EIA and its global behavior at all local times using 1356 ˚A radiance data from high altitu...

  12. An equatorial coronal hole at solar minimum

    Science.gov (United States)

    Bromage, B. J. I.; DelZanna, G.; DeForest, C.; Thompson, B.; Clegg, J. R.

    1997-01-01

    The large transequatorial coronal hole that was observed in the solar corona at the end of August 1996 is presented. It consists of a north polar coronal hole called the 'elephant's trunk or tusk'. The observations of this coronal hole were carried out with the coronal diagnostic spectrometer onboard the Solar and Heliospheric Observatory (SOHO). The magnetic field associated with the equatorial coronal hole is strongly connected to that of the active region at its base, resulting in the two features rotating at almost the same rate.

  13. Equatorial Oscillations in Jupiter's and Saturn's Atmospheres

    Science.gov (United States)

    Flasar, F. Michael; Guerlet, S.; Fouchet, T.; Schinder, P. J.

    2011-01-01

    Equatorial oscillations in the zonal-mean temperatures and zonal winds have been well documented in Earth's middle atmosphere. A growing body of evidence from ground-based and Cassini spacecraft observations indicates that such phenomena also occur in the stratospheres of Jupiter and Saturn. Earth-based midinfrared measurements spanning several decades have established that the equatorial stratospheric temperatures on Jupiter vary with a cycle of 4-5 years and on Saturn with a cycle of approximately 15 years. Spectra obtained by the Composite Infrared Spectrometer (CIRS) during the Cassini swingby at the end of 2000, with much better vertical resolution than the ground-based data, indicated a series of vertically stacked warm and cold anomalics at Jupiter's equator; a similar structurc was seen at Saturn's equator in CIRS limb measurements made in 2005, in the early phase of Cassini's orbital tour. The thermal wind equation implied similar patterns of mean zonal winds increasing and decreasing with altitude. On Saturn the peak-to-pcak amplitude of this variation was nearly 200 meters per second. The alternating vertical pattern of wanner and colder cquatorial tcmperatures and easterly and westerly tendencies of the zonal winds is seen in Earth's equatorial oscillations, where the pattern descends with time, The Cassini Jupiter and early Saturn observations were snapshots within a limited time interval, and they did not show the temporal evolution of the spatial patterns. However, more recent Saturn observations by CIRS (2010) and Cassini radio-occultation soundings (2009-2010) have provided an opportunity to follow the change of the temperature-zonal wind pattern, and they suggest there is descent, at a rate of roughly one scale height over four years. On Earth, the observed descent in the zonal-mean structure is associated with the absorption of a combination of vertically propagating waves with easlerly and westerly phase velocities. The peak-to-peak zonal wind

  14. FLUID EXCHANGE ACROSS THE EQUATORIAL FRONT

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, the cusp-shaped wave pattern (Legeckis wave) along the Equatorial Front (EF) is modeled by a meandering jet, and the motion of fluid parcels in a two-dimensional kinematic model of the meandering jet along EF is studied using Melnikov's method. Results indicated that the velocity field of the cusp-shaped wave pattern can indeed be modeled by a meandering jet; that the EF will act as a barrier to fluid exchange if there is no variability, but that it is just the variability that moves the buoy across the EF.

  15. FLUID EXCHANGE ACROSS THE EQUATORIAL FRONT

    Institute of Scientific and Technical Information of China (English)

    姜传丽; 吕建; 吴德星

    2001-01-01

    In this paper, the cusp-shaped wave pattern (Legeckis wave) along the Equatorial Front (EF) is modeled by a meandering jet, and the motion of fluid parcels in a two-dimensional kine-matic model of the meandering jet along EF is studied using Melnikov's method. Results indicated that the velocity field of the cusp-shaped wave pattern can indeed be modeled by a meandering jet; that the EF will act as a barrier to fluid exchange if there is no variability, but that it is just the variability that moves the buoy across the EF.

  16. The equatorial F-layer: progress and puzzles

    Directory of Open Access Journals (Sweden)

    H. Rishbeth

    Full Text Available This work reviews some aspects of the ionospheric F-layer in the vicinity of the geomagnetic equator. Starting with a historical introduction, brief summaries are given of the physics that makes the equatorial ionosphere so interesting, concentrating on the large-scale structure rather than the smaller-scale instability phenomena. Several individual topics are then discussed, including eclipse effects, the asymmetries of the `equatorial trough', variations with longitude, the semiannual variation, the effects of the global thermospheric circulation, and finally the equatorial neutral thermosphere, including `superrotation' and possible topographic influences.

    Keyword: Ionosphere (equatorial ionosphere

  17. English and Tok Pisin (New Guinea Pidgin English) in Papua New Guinea.

    Science.gov (United States)

    Romaine, Suzanne

    1989-01-01

    Tok Pisin, New Guinea Pidgin English, is becoming increasingly important as a "lingua franca" in Papua New Guinea, even though English is the country's official language. Urban versus rural and spoken versus written varieties of the pidgin are examined, and the influence of English on Tok Pisin is investigated. 73 references. (Author/CB)

  18. LF radio wave propagation at equatorial regions

    Science.gov (United States)

    Boudjada, Mohammed Y.; Sawas, Sami; Galopeau, Patrick H. M.; Eichelberger, Hans; Schwingenschuh, Konrad

    2016-04-01

    We analyse night-side electric field observations recorded by the ICE experiment onboard the DEMETER micro-satellite. We show the presence of multiple spaced frequency bands between 30 kHz and 500 kHz, and sometimes in the range 3 MHz - 3.5 MHz, the upper frequency of the instrument. The frequency bandwidth is found to be less than 5 kHz and the time duration about several minutes. The frequency bands are recorded close to the equatorial plane, when the satellite latitudes extend between -05° and +05°. Particular enhancements occur at two geographical longitudes: 130°E and 160°W. Those LF radio waves may be associated to density irregularities in the equatorial region. These irregularities are occurring along the ray path between the emission source region and the satellite. We discuss in this study the locations where such frequency bands are generated, and we show that the observed spectral features may be comparable to the kilometric continuum radiation which is considered as a non-thermal radio emission.

  19. Fading of Jupiter's South Equatorial Belt

    Science.gov (United States)

    Sola, Michael A.; Orton, Glenn; Baines, Kevin; Yanamandra-Fisher, Padma

    2011-01-01

    One of Jupiter's most dominant features, the South Equatorial Belt, has historically gone through a "fading" cycle. The usual dark, brownish clouds turn white, and after a period of time, the region returns to its normal color. Understanding this phenomenon, the latest occurring in 2010, will increase our knowledge of planetary atmospheres. Using the near infrared camera, NSFCAM2, at NASA's Infrared Telescope Facility in Hawaii, images were taken of Jupiter accompanied by data describing the circumstances of each observation. These images are then processed and reduced through an IDL program. By scanning the central meridian of the planet, graphs were produced plotting the average values across the central meridian, which are used to find variations in the region of interest. Calculations using Albert4, a FORTRAN program that calculates the upwelling reflected sunlight from a designated cloud model, can be used to determine the effects of a model atmosphere due to various absorption, scattering, and emission processes. Spectra that were produced show ammonia bands in the South Equatorial Belt. So far, we can deduce from this information that an upwelling of ammonia particles caused a cloud layer to cover up the region. Further investigations using Albert4 and other models will help us to constrain better the chemical make up of the cloud and its location in the atmosphere.

  20. Midday reversal of equatorial ionospheric electric field

    Directory of Open Access Journals (Sweden)

    R. G. Rastogi

    Full Text Available A comparative study of the geomagnetic and ionospheric data at equatorial and low-latitude stations in India over the 20 year period 1956–1975 is described. The reversal of the electric field in the ionosphere over the magnetic equator during the midday hours indicated by the disappearance of the equatorial sporadic E region echoes on the ionograms is a rare phenomenon occurring on about 1% of time. Most of these events are associated with geomagnetically active periods. By comparing the simultaneous geomagnetic H field at Kodaikanal and at Alibag during the geomagnetic storms it is shown that ring current decreases are observed at both stations. However, an additional westward electric field is superimposed in the ionosphere during the main phase of the storm which can be strong enough to temporarily reverse the normally eastward electric field in the dayside ionosphere. It is suggested that these electric fields associated with the V×Bz electric fields originate at the magnetopause due to the interaction of the solar wind and the interplanetary magnetic field.

  1. Central Equatorial Pacific Experiment (CEPEX). Design document

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    The Earth`s climate has varied significantly in the past, yet climate records reveal that in the tropics, sea surface temperatures seem to have been remarkably stable, varying by less than a few degrees Celsius over geologic time. Today, the large warm pool of the western Pacific shows similar characteristics. Its surface temperature always exceeds 27{degree}C, but never 31{degree}C. Heightened interest in this observation has been stimulated by questions of global climate change and the exploration of stabilizing climate feedback processes. Efforts to understand the observed weak sensitivity of tropical sea surface temperatures to climate forcing has led to a number of competing ideas about the nature of this apparent thermostat. Although there remains disagreement on the processes that regulate tropical sea surface temperature, most agree that further progress in resolving these differences requires comprehensive field observations of three-dimensional water vapor concentrations, solar and infrared radiative fluxes, surface fluxes of heat and water vapor, and cloud microphysical properties. This document describes the Central Equatorial Pacific Experiment (CEPEX) plan to collect such observations over the central equatorial Pacific Ocean during March of 1993.

  2. Observational features of equatorial coronal hole jets

    Directory of Open Access Journals (Sweden)

    G. Zimbardo

    2010-03-01

    Full Text Available Collimated ejections of plasma called "coronal hole jets" are commonly observed in polar coronal holes. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. In this paper we present some observations of "equatorial coronal hole jets" made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and December 2007. The jet events are selected by requiring at least some visibility in both COR1 and EUVI instruments. We report 15 jet events, and we discuss their main features. For one event, the uplift velocity has been determined as about 200 km s−1, while the deceleration rate appears to be about 0.11 km s−2, less than solar gravity. The average jet visibility time is about 30 min, consistent with jet observed in polar regions. On the basis of the present dataset, we provisionally conclude that there are not substantial physical differences between polar and equatorial coronal hole jets.

  3. Determination of the Current System on Isopycnal Surface Between Mindanao and New Guinea from GDEM

    Institute of Scientific and Technical Information of China (English)

    Peter C Chu; LI Rongfeng; FAN Chenwu

    2003-01-01

    In this study, we used the Navy's Generalized Digital Environmental Model(GDEM) climatological temperature and salinity data on a 0.5°× 0.5° grid to investigate the seasonal variabilities of the southwest Philippines Sea (0.5° - 9°N, 123.5o - 136.5°) thermohaline structure and circulation. The GDEM for the area was built up on historical (1930 - 1997) temperature and salinity profiles. A three-dimensional estimate of the absolute geostrophic velocity field on isopycnal surface was obtained from the GDEM temperature and salinity fields using the P-vector method. The seasonal variabilities of the thermohaline structure and currents (obtained from the inverse method) such as the Mindanao Current, Mindanao Undercurrent, North Equatorial Counter Current, New Guinea Coastal Undercurrent, and dual-eddieS (cyclonic Mindanao Eddy and anticyclonic Halmahera Eddy) are identified.

  4. Cenozoic Source-to-Sink of the African margin of the Equatorial Atlantic

    Science.gov (United States)

    Rouby, Delphine; Chardon, Dominique; Huyghe, Damien; Guillocheau, François; Robin, Cecile; Loparev, Artiom; Ye, Jing; Dall'Asta, Massimo; Grimaud, Jean-Louis

    2016-04-01

    The objective of the Transform Source to Sink Project (TS2P) is to link the dynamics of the erosion of the West African Craton to the offshore sedimentary basins of the African margin of the Equatorial Atlantic at geological time scales. This margin, alternating transform and oblique segments from Guinea to Nigeria, shows a strong structural variability in the margin width, continental geology and relief, drainage networks and subsidence/accumulation patterns. We analyzed this system combining onshore geology and geomorphology as well as offshore sub-surface data. Mapping and regional correlation of dated lateritic paleo-landscape remnants allows us to reconstruct two physiographic configurations of West Africa during the Cenozoic. We corrected those reconstitutions from flexural isostasy related to the subsequent erosion. These geometries show that the present-day drainage organization stabilized by at least 29 Myrs ago (probably by 34 Myr) revealing the antiquity of the Senegambia, Niger and Volta catchments toward the Atlantic as well as of the marginal upwarp currently forming a continental divide. The drainage rearrangement that lead to this drainage organization was primarily enhanced by the topographic growth of the Hoggar swell and caused a major stratigraphic turnover along the Equatorial margin of West Africa. Elevation differences between paleo-landscape remnants give access to the spatial and temporal distribution of denudation for 3 time-increments since 45 Myrs. From this, we estimate the volumes of sediments and associated lithologies exported by the West African Craton toward different segments of the margin, taking into account the type of eroded bedrock and the successive drainage reorganizations. We compare these data to Cenozoic accumulation histories in the basins and discuss their stratigraphic expression according to the type of margin segment they are preserved in.

  5. Development of a campaign to study equatorial ionospheric phenomena over Guam

    Science.gov (United States)

    Habash Krause, L.; Balthazor, R.; McHarg, M. G.; Reinisch, B. W.

    2008-08-01

    The United States Air Force Academy (USAFA) is in the process of developing a series of ground-based and space-based experiments to investigate the equatorial ionosphere over Guam and the southern crest of the Equatorial Appleton Anomaly over New Guinea. On the ground the Digital Ionospheric Sounder (University of Massachusetts, Lowell DPS-4 unit) and a dual-frequency GPS TEC/scintillation monitor will be used to investigate ionospheric phenomena in both campaign and long-term survey modes. In campaign mode, we will combine these observations with those collected from space during USAFA's FalconSAT-3 and FalconSAT-5 low Earth orbit satellite missions, which will be active over a period of several years beginning in the first quarter of the 2007 calendar year. Additionally, we will investigate the long-term morphology of key ionospheric characteristics useful for driving the International Reference Ionosphere, such as critical frequencies (f oE, f oF1, f oF2, etc.), the M(3000) F2 parameter (the maximum useable frequency for a signal refracted within the F2 layer and received on the ground at a distance of 3000 km away), and a variety of other characteristics. Specific targets of investigation include: (a) a comparison of TEC observed by the GPS receiver with those calculated by IRI driven by DPS-4 observations, (b) a comparison of plasma turbulence observed on-orbit with ionospheric conditions as measured from the ground, and (c) a comparison between topside ionospheric satellite in situ measurements of plasma density during an overpass of a Digisonde versus the calculated value based on extrapolation of the electron density profiles using Digisonde data and a topside α-Chapman function. This last area of investigation is discussed in detail in this paper.

  6. En la frontera del ciclo vital: el ritual del tuparápará entre los bubis de Guinea Ecuatorial

    OpenAIRE

    Fernández Moreno, Nuria

    2005-01-01

    El texto describe un rito de iniciación al recién nacido entre los bubis de la isla de Bioko. A partir de la etnografía que presenta tanto del ritual como del contexto sociocultural de la etnia bubi, se aborda el contenido simbólico y el análisis est

  7. Phytochelatin concentrations in the equatorial Pacific

    Science.gov (United States)

    Ahner, Beth A.; Lee, Jennifer G.; Price, Neil M.; Morel, François M. M.

    1998-11-01

    Phytochelatin, an intracellular metal-binding polypeptide synthesized in eucaryotic algae in response to metals such as Cd and Cu, was measured in particulate samples collected from the equatorial Pacific. The concentrations in these samples (normalized to total particulate chl a) were unexpectedly high compared to laboratory culture data and were on average slightly more than in coastal areas where the metal concentrations are typically much greater. In part, the high field concentrations can be explained by the low cellular concentrations of chlorophyll a resulting from very low ambient Fe, but laboratory experiments provide a possible explanation for the rest of the difference. At low concentrations of inorganic Cd (Cd'=3 pM), increasing amounts of phytochelatin were induced by decreasing Zn concentrations in the culture medium of two diatoms: Thalassiosira weissflogii, a coastal species, and T. parthenaia, an isolate from the equatorial Pacific. In all previous studies, phytochelatin production has been directly correlated with increasing metal concentrations. Decreasing Co also resulted in higher phytochelatin concentrations in T. weissflogii and Emiliania huxleyi. Replicating the field concentrations of Zn, Co, and Cd in the laboratory results in cellular concentrations (amol -1 cell) that are very similar to those estimated for the field. Contrary to the expectation that high metal concentrations in the equatorial upwelling would cause elevated phytochelatin concentrations, there was no increase in phytochelatin concentrations from 20° S to 10° N—near surface samples were roughly the same at all stations. Also, most of the depth profiles had a distinct subsurface maximum. Neither of these features is readily explained by the available Zn and Cd data. Incubations with additions of Cd and Cu performed on water sampled at four separate stations induced significantly higher concentrations of phytochelatins than those in controls in a majority of the samples

  8. Investigation of TEC variations over the magnetic equatorial and equatorial anomaly regions of the African sector

    Science.gov (United States)

    Oryema, B.; Jurua, E.; D'ujanga, F. M.; Ssebiyonga, N.

    2015-11-01

    This paper presents the annual, seasonal and diurnal variations in ionospheric TEC along the African equatorial region. The study also investigated the effects of a geomagnetic storm on ionospheric TEC values. Dual-frequency GPS derived TEC data obtained from four stations within the African equatorial region for the high solar activity year 2012 were used in this study. Annual variations showed TEC having two peaks in the equinoctial months, while minima values were observed in the summer and winter solstices. The diurnal pattern showed a pre-dawn minimum, a steady increase from about sunrise to an afternoon maximum and then a gradual fall after sunset to attain a minimum just before sunrise. Nighttime enhancements of TEC were observed mostly in the equinoctial months. There was comparably higher percentage TEC variability during nighttime than daytime and highest during equinoxes, moderate in winter and least during summer solstice. TEC was observed to exhibit a good correlation with geomagnetic storm indices.

  9. Long wavelength irregularities in the equatorial electrojet

    International Nuclear Information System (INIS)

    We have used the radar interferometer technique at Jicamarca to study in detail irregularities with wavelengths of a few kilometers generated in the unstable equatorial electrojet plasma during strong type 1 conditions. In-situ rocket observations of the same instability process are discussed in a companion paper. These large scale primary waves travel essentially horizontally and have large amplitudes. The vertical electron drift velocities driven by the horizontal wave electric fields reach or exceed the ion-acoustic velocity even though the horizontal phase velocity of the wave is considerably smaller. A straightforward extension to the long wavelength regime of the usual linear theory of the electrojet instability explains this and several other observed features of these dominant primary waves

  10. Alkylmercury species in the equatorial Pacific

    Science.gov (United States)

    Mason, R. P.; Fitzgerald, W. F.

    1990-10-01

    HIGH levels of mercury in piscivorous fish constitute a long-standing health hazard1-6. Monomethyl mercury, the main form of mercury in fish, is more toxic than inorganic mercury. But although something is known of the ability of organisms to methylate mercury7,8, the sources, synthesis and fate of methyl mercury in aquatic waters are not well understood. Inorganic and alkylated mercury has been studied in natural waters9-11, precipitation and the atmosphere12,13. We now report evidence of monomethyl and dimethyl mercury in the low-oxygen waters of the equatorial Pacific. The presence of these species has important implications for our understanding of the biogeochemical cycling of mercury in the marine environment. Although the source of monomethyl mercury in open-ocean fish is still unknown, our data show that a pathway exists for the accumulation of methylated mercury in marine pelagic fish.

  11. Equatorial trench at the magnetopause under saturation

    CERN Document Server

    Dmitriev, A; 10.1029/2012JA017834

    2013-01-01

    Magnetic data from GOES geosynchronous satellites were applied for statistical study of the low-latitude dayside magnetopause under a strong interplanetary magnetic field of southward orientation when the reconnection at the magnetopause was saturated. From minimum variance analysis, we determined the magnetopause orientation and compared it with predictions of a reference model. The magnetopause shape was found to be substantially distorted by a duskward shifting such that the nose region appeared in the postnoon sector. At equatorial latitudes, the shape of magnetopause was characterized by a prominent bluntness and by a trench formed in the postnoon sector. The origin of distortions was regarded in the context of the storm-time magnetospheric currents and the large-scale quasi-state reconnection at the dayside magnetopause.

  12. The effect of Congo River freshwater discharge on Eastern Equatorial Atlantic climate variability

    Energy Technology Data Exchange (ETDEWEB)

    Materia, Stefano [Centro Euro-Mediterraneo per i Cambiamenti Climatici, Bologna (Italy); Gualdi, Silvio; Navarra, Antonio [Centro Euro-Mediterraneo per i Cambiamenti Climatici, Bologna (Italy); Istituto Nazionale di Geofisica e Vulcanologia, Bologna (Italy); Terray, Laurent [Sciences de l' Univers au CERFACS, URA1875 CERFACS/CNRS, Toulouse (France)

    2012-11-15

    The surface ocean explains a considerable part of the inter-annual Tropical Atlantic variability. The present work makes use of observational datasets to investigate the effect of freshwater flow on sea surface salinity (SSS) and temperature (SST) in the Gulf of Guinea. In particular, the Congo River discharges a huge amount of freshwater into the ocean, affecting SSS in the Eastern Equatorial Atlantic (EEA) and stratifying the surface layers. The hypothesis is that an excess of river runoff emphasize stratification, influencing the ocean temperature. In fact, our findings show that SSTs in the Gulf of Guinea are warmer in summers following an anomalously high Congo spring discharge. Vice versa, when the river discharges low freshwater, a cold anomaly appears in the Gulf. The response of SST is not linear: temperature anomalies are considerable and long-lasting in the event of large freshwater flow, while in dry years they are less remarkable, although still significant. An excess of freshwater seems able to form a barrier layer, which inhibits vertical mixing and the entrainment of the cold thermocline water into the surface. Other processes may contribute to SST variability, among which the net input of atmospheric freshwater falling over EEA. Likewise the case of continental runoff from Congo River, warm anomalies occur after anomalously rainy seasons and low temperatures follow dry seasons, confirming the effect of freshwater on SST. However, the two sources of freshwater anomaly are not in phase, so that it is possible to split between atypical SST following continental freshwater anomalies and rainfall anomalies. Also, variations in air-sea fluxes can produce heating and cooling of the Gulf of Guinea. Nevertheless, atypical SSTs cannot be ascribed to fluxes, since the temperature variation induced by them is not sufficient to explain the SST anomalies appearing in the Gulf after anomalous peak discharges. The interaction processes between river runoff, sea

  13. The strategy of the key players in the African oil sector (the Gulf of Guinea)?

    International Nuclear Information System (INIS)

    The African oil industry, (particularly in the deep water offshore fields of the Gulf of Guinea), is symbolic of the new balance of power taking shape in the oil industry between the international companies and the host state on the one hand, and between the petrol companies themselves on the other. In an area rich in potential and which has become highly competitive, the traditional players in the region's oil development sector (Shell, Chevron and TotalFinaElf) which have for so long been sheltered from genuine competition in their respective areas of activity, must now face up to the renewed ambitions of new 'Super Majors' (in particular ExxonMobil), not to mention those of many independent companies seeking to internationalize their business. Several reasons explain this change. Firstly, the main developments are now taking place offshore with deep water drilling, and financial solidity and technological competence have replaced the closeness of political links as key factors of success. In these conditions, the risk of long term marginalization for the medium-sized companies is considerable. Secondly, the need to achieve profitability stressed by the major petrol groups is opening the door to the independents who are operating a niche policy (based on marginal or mature fields which no longer interest the majors). This type of competition tends to promote activity and to open up new countries to exploration and production (in particular Equatorial Guinea). (author)

  14. Herpetofauna del Parque Nacional de Monte Alén (Río Muni, Guinea Ecuatorial

    Directory of Open Access Journals (Sweden)

    Lasso, C. A.

    2002-12-01

    Full Text Available In the framework of a broad study of the vertebrate diversity at Monte Alen National Park (Río Muni, Equatorial Guinea, we identified 16 families, 47 genera, and 65 species of reptiles and seven families, 29 genera, and 56 species of amphibians. 21 species of reptiles and four species of amphibians represent new records for the Río Muni region. We present the preliminary inventory of the herpetofauna as well as some ecological comments. Monte Alén is considered one of the most diverse protected areas in central Africa from a herpetological standpoint.

    En el marco de un estudio general sobre de la diversidad de vertebrados del Parque Nacional de Monte Alén (Río Muni, Guinea Ecuatorial, se identificaron 16 familias, 47 géneros y 65 especies de reptiles, y 7 familias, 29 géneros y 56 especies de anfibios; 21 especies de reptiles y 4 de anfibios representan nuevos registros para la región de Río Muni. En el presente trabajo se expone el inventario preliminar de especies e información ecológica puntual sobre las mismas. Monte Alén puede ser considerada una de las áreas protegidas de mayor diversidad herpetológica de África central.

  15. Dynamical variability in Saturn Equatorial Atmosphere

    Science.gov (United States)

    Sánchez-Lavega, A.; Pérez-Hoyos, S.; Hueso, R.; Rojas, J. F.; French, R. G.; Grupo Ciencias Planetarias Team

    2003-05-01

    Historical ground-based and recent HST observations show that Saturn's Equatorial Atmosphere is the region where the most intense large-scale dynamical variability took place at cloud level in the planet. Large-scale convective storms (nicknamed the ``Great White Spots") occurred in 1876, 1933 and 1990. The best studied case (the 1990 storm), produced a dramatic change in the cloud aspect in the years following the outburst of September 1990. Subsequently, a new large storm formed in 1994 and from 1996 to 2002 our HST observations showed periods of unusual cloud activity in the southern part of the Equator. This contrast with the aspect observed during the Voyager 1 and 2 encounters in 1980 and 1981 when the Equator was calm, except for some mid-scale plume-like features seen in 1981. Cloud-tracking of the features have revealed a dramatic slow down in the equatorial winds from maximum velocities of ˜ 475 m/s in 1980-1981 to ˜ 275 m/s during 1996-2002, as we have recently reported in Nature, Vol. 423, 623 (2003). We discuss the possibility that seasonal and ring-shadowing effects are involved in generating this activity and variability. Acknowledgements: This work was supported by the Spanish MCYT PNAYA 2000-0932. SPH acknowledges a PhD fellowship from the Spanish MECD and RH a post-doc fellowship from Gobierno Vasco. RGF was supported in part by NASA's Planetary Geology and Geophysics Program NAG5-10197 and STSCI Grant GO-08660.01A.

  16. Digital ionosonde observations during equatorial spread F

    International Nuclear Information System (INIS)

    In this paper we present and discuss equatorial spread F data taken with a digital ionosonde/HF radar located at Huancayo, Peru. A modified phenomenology is developed which uses the system's ability to do echo location. The onset of irregularities is seen to occur in the east and to move westward, while inside this large-scale structure the plasma is found to drift eastward. A very curious difference has been identified between spread F observations with the ionosonde and with the VHF radar at Jicamarca. At VHF, spread F onset often occurs when the ionosphere is rising, whereas in all five examples presented here, the digital ionosonde detected onset when the apparent ionosphere motion was downward. The result even held on the one night of common data taking. The effect could be instrumental but may be related to the considerable orographic differences in the two sites. Isolated scattering patches are observed and are tentatively identified as detached or ''fossil'' plumes. At frequencies above the nominal f0F2 the system (and other ionosondes) may in fact function as a coherent radar. During one night, data were obtained simultaneously with the HF radar, a rocket, and the Jicamarca VHF radar. Comparisons of these data are discussed in detail. Finally, additional evidence is presented that acoustic gravity waves play a role in the development of equatorial spread F and in the formation of detached plumes. To be self-consistent, the gravity waves must come from nearby sources such as the tropical rain forest to the east of Jicamarca

  17. Malignant transformation of guinea pig cells after exposure to ultraviolet-irradiated guinea pig cytomegalovirus

    International Nuclear Information System (INIS)

    Guinea pig cells were malignantly transformed in vitro by ultraviolet (uv)-irradiated guinea pig cytomegalovirus (GPCMV). When guinea pig hepatocyte monolayers were infected with uv-irradiated GPCMV, three continuous epithelioid cell lines which grew in soft agarose were established. Two independently derived GPCMV-transformed liver cells and a cell line derived from a soft agarose clone of one of these lines induced invasive tumors when inoculated subcutaneously or intraperitoneally into nude mice. The tumors were sarcomas possibly derived from hepatic stroma or sinusoid. Transformed cell lines were also established after infection of guinea pig hepatocyte monolayers with human cytomegalovirus (HCMV) or simian virus 40 (SV40). These cell lines also formed colonies in soft agarose and induced sarcomas in nude mice. It is concluded that (i) GPCMV can malignantly transform guinea pig cells; (ii) cloning of GPCMV-transformed cells in soft agarose produced cells that induced tumors with a shorter latency period but with no alteration in growth rate or final tumor size; and (iii) the tumors produced by GPCMV-and HCMV-transformed guinea pig cells were more similar to each other in growth rate than to those induced by SV40-transformed guinea pig cells

  18. Equatorial night-time spread-F characteristics observed from stations in the Western Pacific

    International Nuclear Information System (INIS)

    A comparative study of the ionospheric spread-F observed at an equatorial station. Port Moresby (9024.5'S, 14709.9'E; magn. Dip lat. 180S), Papua new Guinea, with corresponding data from the East Asian stations during a period 27 May-19 Jun 1983, as well as the same periods for 1981 and 1982, is presented. The Port Moresby spread-F condition is particularly outstanding and persistent at night and the occurrence of spread-F between 23 LT and 05 LT near June solstice is very high, reaching 100% of all observed nights. The latitudinal variation of nocturnal spread-F, its duration and connection with sunspot number are analyzed. The relationship between long-term variation of night-time spread-F occurrence and solar activity during June and December solstices from 1954 up to 1984 at a typical lower magnetic latitudinal station. Wuhan (30032.7'N, 114021.5'E; magn. dip lat. 260N), is also investigated. (author)

  19. The World's Largest Submarine Canyon—Kroenke Canyon in the Western Equatorial Pacific

    Science.gov (United States)

    Coffin, M. F.; Adams, N.; Whittaker, J. M.; Lucieer, V.; Heckman, M.; Ketter, T.; Neale, J. F.; Reyes, A.; Travers, A.

    2015-12-01

    Kroenke Canyon lies on the Ontong Java Plateau (OJP) in the western Equatorial Pacific, between the Solomon Islands and the Federated States of Micronesia. In late 2014 aboard the Schmidt Ocean Institute's RV Falkor, we mapped, albeit incompletely, the Canyon for the first time, revealing that it is both the longest (>700 km) and the most voluminous (>6800 km3) submarine canyon yet discovered on Earth. Kroenke Canyon appears to originate in the vicinity of Ontong Java (Solomon Islands) and Nukumanu (Papua New Guinea) atolls, and presumably began to develop when the atolls were high-standing volcanic islands surmounting the ~120 Ma igneous basement of the OJP. The Canyon is characterised by numerous tributaries and significant mass wasting. Kroenke Canyon incises the layer-cake stratigraphy of OJP sediment and sedimentary rock, mostly carbonate with some interbedded chert, which has provided numerous slip surfaces for submarine landslides. The carbonate compensation depth (CCD) roughly coincides with the depth of the transition between the OJP and the neighbouring Nauru Basin. As a result, despite the large volume of sediment eroded and transported by canyon-forming processes, only a minor fan is evident in the Nauru Basin because most of the carbonate has dissolved.

  20. ARM Research in the Equatorial Western Pacific: A Decade and Counting

    Energy Technology Data Exchange (ETDEWEB)

    Long, Charles N.; McFarlane, Sally A.; Del Genio, Anthony D.; Minnis, Patrick; Ackerman, Thomas P.; Mather, James H.; Comstock, Jennifer M.; Mace, Gerald G.; Jensen, Michael; Jakob, Christian

    2013-05-22

    The tropical western Pacific (TWP) is an important climatic region. Strong solar heating, warm sea surface temperatures and the annual progression of the Intertropical Convergence Zone (ITCZ) across this region generate abundant convective systems, which through their effects on the heat and water budgets have a profound impact on global climate and precipitation. To accurately represent tropical cloud systems in models, measurements of tropical clouds, the environment in which they reside, and their impact on the radiation and water budgets are needed. Because of the remote location, ground-based datasets of cloud, atmosphere, and radiation properties from the TWP region have traditionally come primarily from short-term field experiments. While providing extremely useful information on physical processes, these datasets are limited in statistical and climatological information because of their short duration. To provide long-term measurements of the surface radiation budget in the tropics, and the atmospheric properties that affect it, the Atmospheric Radiation Measurement program established a measurement site on Manus Island, Papua New Guinea in 1996 and on the island republic of Nauru in late 1998. These sites provide unique datasets available from more than 10 years of operation in the equatorial western Pacific on Manus and Nauru. We present examples of the scientific use of these datasets including characterization of cloud properties, analysis of cloud radiative forcing, model studies of tropical clouds and processes, and validation of satellite algorithms. We also note new instrumentation recently installed at the Manus site that will expand opportunities for tropical atmospheric science.

  1. Vitamin C deficiency in weanling guinea pigs

    DEFF Research Database (Denmark)

    Lykkesfeldt, Jens; Trueba, Gilberto Perez; Poulsen, Henrik E.;

    2007-01-01

    Neonates are particularly susceptible to malnutrition due to their limited reserves of micronutrients and their rapid growth. In the present study, we examined the effect of vitamin C deficiency on markers of oxidative stress in plasma, liver and brain of weanling guinea pigs. Vitamin C deficiency...... increased, while protein oxidation decreased (P¼0003). The results show that the selective preservation of brain ascorbate and induction of DNA repair in vitamin C-deficient weanling guinea pigs is not sufficient to prevent oxidative damage. Vitamin C deficiency may therefore be particularly adverse during...

  2. Lidar Observation of Tropopause Ozone Profiles in the Equatorial Region

    Science.gov (United States)

    Shibata, Yasukuni; Nagasawa, Chikao; Abo, Makoto

    2016-06-01

    Tropospheric ozone in the tropics zone is significant in terms of the oxidizing efficiency and greenhouse effect. However, in the upper troposphere, the ozone budget in the tropics has not been fully understood yet because of the sparsity of the range-resolved observations of vertical ozone concentration profiles. A DIAL (differential absorption lidar) system for vertical ozone profiles have been installed in the equatorial tropopause region over Kototabang, Indonesia (100.3E, 0.2S). We have observed large ozone enhancement in the upper troposphere, altitude of 13 - 17 km, concurring with a zonal wind oscillation associated with the equatorial Kelvin wave around the tropopause at equatorial region.

  3. Equatorial Rossby Solitary Wave Under the External Forcing

    Institute of Scientific and Technical Information of China (English)

    FU Zun-Tao; LIU Shi-Kuo; LIU Shi-Da

    2005-01-01

    A simple shallow-water model with influence of external forcing on a β-plane is applied to investigate the nonlinear equatorial Rossby waves in a shear flow. By the perturbation method, the extended variable-coefficient KdV equation under an external forcing is derived for large amplitude equatorial Rossby wave in a shear flow. And then various periodic-like structures for these equatorial Rossby waves are obtained with the help of Jacobi elliptic functions.It is shown that the external forcing plays an important role in various periodic-like structures.

  4. Equatorial cloud level convection on Venus

    Science.gov (United States)

    Lee, Yeon Joo; Imamura, Takeshi; Sugiyama, Koichiro; Sato, Takao M.; Maejima, Yasumitsu

    2016-10-01

    In the equatorial region on Venus, a clear cloud top morphology difference depending on solar local time has been observed through UV images. Laminar flow shaped clouds are shown on the morning side, and convective-like cells on the afternoon side (Titov et al. 2012). Baker et al. (1998) suggested that deep convective motions in the low-to-middle cloud layers at the 40–60 km range can explain cellular shapes. Imamura et al. (2014), however argued that this cannot be a reason, as convection in the low-to-middle cloud layers can be suppressed near sub solar regions due to a stabilizing effect by strong solar heating. We suggest that the observed feature may be related to strong solar heating at local noon time (Lee et al. 2015). Horizontal uneven distribution of an unknown UV absorber and/or cloud top structure may trigger horizontal convection (Toigo et al. 1994). In order to examine these possibilities, we processed 1-D radiative transfer model calculations from surface to 100 km altitude (SHDOM, Evans 1998), which includes clouds at 48-71 km altitudes (Crisp et al. 1986). The results on the equatorial thermal cooling and solar heating profiles were employed in a 2D fluid dynamic model calculation (CReSS, Tsuboki and Sakakibara 2007). The calculation covered an altitude range of 40-80 km and a 100-km horizontal distance. We compared three conditions; an 'effective' global circulation condition that cancels out unbalanced net radiative energy at equator, a condition without such global circulation effect, and the last condition assumed horizontally inhomogeneous unknown UV absorber distribution. Our results show that the local time dependence of lower level cloud convection is consistent with Imamura et al.'s result, and suggest a possible cloud top level convection caused by locally unbalanced net energy and/or horizontally uneven solar heating. This may be related to the observed cloud morphology in UV images. The effective global circulation condition, however

  5. Tilts of the Master Equatorial Tower

    Science.gov (United States)

    Ahlstrom, H. G., Jr.; Gawronski, W.; Girdner, D.; Noskoff, E.; Sommerville, J. N.

    2000-07-01

    At the center of the DSS-14 antenna, a tower reaches to the focal point of the antenna dish. The master equatorial (ME) instrument is located at the top of the tower. This instrument precisely (with an accuracy that exceeds that of the antenna) follows the commanded trajectory. Through the optical coupling, the antenna focal point follows the ME. One factor of the antenna pointing precision is the movement of the ME base, i.e., the top of the tower. For this reason, measurements of the ME tower tilts have been taken in order to quantify the tilts, to determine possible causes of the tilting, and to update the antenna pointing budget. They were conducted under three antenna operating modes: during tracking, slewing, and antenna stowing. The measurements indicate that the ME tower tilts introduce significant pointing errors that exceed the required 32-GHz (Ka-band) pointing precision (estimated as 0.8 mdeg for a 0.1-dB gain loss). Four different sources of tilt were identified and require verification.

  6. Equatorial electrojet in east Brazil longitudes

    Indian Academy of Sciences (India)

    R G Rastogi; H Chandra; K Yumuto

    2010-08-01

    This paper describes the morphology of the equatorial electrojet (EEJ) along 45°W longitude in east Brazil, where the ground magnetic (dip) equator is associated with the largest declination in the world. Daily range of the horizontal field ( ), as expected, was largest at the station in the chain closest to the dip equator, Sao Luiz (inclination −0.25°S). was largest positive at Eusebio (inclination 9.34°S) and largest negative at Belem (inclination 7.06°N); both near the fringe of EEJ belt. at Sao Luiz during the daytime was unexpectedly large negative in-spite of a small dip and also located south of the dip equator where should be positive. Center of EEJ was found to be shifted southward of the dip equator by about 1° in latitude. During southern summer, started decreasing from 00 h and reached a minimum value in the afternoon, an abnormal feature not discussed for any station so far. The mid-day value of the direction of vector was 22°-24°W compared to the declination of 19°–21°W in the region.

  7. Observational features of equatorial coronal hole jets

    CERN Document Server

    Nistico', G; Patsourakos, S; Zimbardo, G

    2010-01-01

    Collimated ejections of plasma called "coronal hole jets" are commonly observed in polar coronal holes. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. In this paper we present some observations of "equatorial coronal hole jets" made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and December 2007. The jet events are selected by requiring at least some visibility in both COR1 and EUVI instruments. We report 15 jet events, and we discuss their main features. For one event, the uplift velocity has been determined as about 200 km/s, while the deceleration rate appears to be about 0.11 km/s2, less than solar gravity. The average jet visibility time is about 30 minutes, consistent with jet observed in polar regions. On the basis of the present dataset, we provisionally conclude that there are not substantial physical differences between polar and eq...

  8. Plasma instabilities multifrequency study in equatorial electrojet

    International Nuclear Information System (INIS)

    In this thesis, multifrequential HF coherent radar results are presented, in the field plasma instabilities in equatorial electrojet. In a first part, characteristics of the irregularities observed either at the 3 meter wavelength by VHF radars, either at other wavelengths during pinpoint experiments, or in-situ by probe rockets are recalled. Theoretical studies progressed and are presented, at the same time with these experimental observations: instability linear theory, non linear theories, HF radar specificity, and problems associated to HF waves propagation and refraction in ionosphere. Original experimental results from Ethiopia are gathered in the second part. Plasma instability has been studied in different geophysical conditions and Doppler spectra characteristics are presented for each one of them. These characteristics are completely different according to the various cases; they are also different according to wether observations are made during the day in normal conditions (electric field pointed to the east at the equator) or in counter-electrojet conditions (electric field pointed to the west). The last part is concerned with theoretical interpretation of the previous results. A comprehensive view of the instability physical mechanisms, according to the geophysical conditions encountered, has been allowed by our results, VHF radar measurements at Jicamarca, or in situ probe measurements on the whole. Irregularities study has been limited to the E region

  9. Multiple equilibria of cross-equatorial Inertial jets

    Institute of Scientific and Technical Information of China (English)

    CHAO JiPing; LIU Fei

    2007-01-01

    Based on the developed Anderson and Moore's theory about cross-equatorial inertial jets and a nonlinear equivalence shallow water model, new universal functions are determined by the characters of the vortical large-scale air flow (atmosphere) or ocean current (ocean) related to the jet, then the potential vorticity and energy conservation equations along the streamline in the cross-equatorial inertial jets can be obtained. Because the governing equations are nonlinear, some limited multiple equilibria of cross-equatorial inertial jets may exist. According to the character of large-scale air flow or ocean current outside the jets, the existent criterion for multiple eqnilibria in cross-equatorial inertial jets is discussed, and two examples for multiple equilibia of nonlinear governing equations are given.

  10. Multiple equilibria of cross-equatorial Inertial jets

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the developed Anderson and Moore’s theory about cross-equatorial inertial jets and a nonlinear equivalence shallow water model, new universal functions are determined by the characters of the vortical large-scale air flow (atmosphere) or ocean current (ocean) related to the jet, then the potential vorticity and energy conservation equations along the streamline in the cross-equatorial in-ertial jets can be obtained. Because the governing equations are nonlinear, some limited multiple equi-libria of cross-equatorial inertial jets may exist. According to the character of large-scale air flow or ocean current outside the jets, the existent criterion for multiple eqnilibria in cross-equatorial inertial jets is discussed, and two examples for multiple equilibia of nonlinear governing equations are given.

  11. Modelling the development of mixing height in near equatorial region

    Energy Technology Data Exchange (ETDEWEB)

    Samah, A.A. [Univ. of Malaya, Air Pollution Research Unit, Kuala Lumpur (Malaysia)

    1997-10-01

    Most current air pollution models were developed for mid-latitude conditions and as such many of the empirical parameters used were based on observations taken in the mid-latitude boundary layer which is physically different from that of the equatorial boundary layer. In the equatorial boundary layer the Coriolis parameter f is small or zero and moisture plays a more important role in the control of stability and the surface energy balance. Therefore air pollution models such as the OMLMULTI or the ADMS which were basically developed for mid-latitude conditions must be applied with some caution and would need some adaptation to properly simulate the properties of equatorial boundary layer. This work elucidates some of the problems of modelling the evolution of mixing height in the equatorial region. The mixing height estimates were compared with routine observations taken during a severe air pollution episodes in Malaysia. (au)

  12. Piraatlus Guinea lahes ja Nigeerias / Eero Tepp

    Index Scriptorium Estoniae

    Tepp, Eero

    2013-01-01

    Guinea lahes lokkava piraatluse põhjused ja tegurid, mis seda soodustavad: seaduselüngad, looduslikud tingimused, ebapädev korrakaitse, poliitiline olustik, kultuuriline vastuvõetavus, majanduslik tasuvus. Sõjalised ja mittesõjalised meetmetest, mida rakendatakse piraatlusevastases võitluses

  13. The Papua and New Guinea Herbarium

    NARCIS (Netherlands)

    Womersley, J.S.; Botanist, Forest

    1951-01-01

    A short account of the establishment of the Herbarium of the Department of Forests, Papua and New Guinea appeared on p. 61, no 3, volume I of Flora Malesiana Bulletin. This Herbarium has now been firmly established and is constantly receiving collections of plants from various parts of Papua and New

  14. Public Library Development in Papua New Guinea.

    Science.gov (United States)

    Wijasuriya, D. E. K.; Evans, John

    1992-01-01

    Presents the findings and recommendations of a consultant supported by UNESCO who prepared a public library development plan for Papua New Guinea. Highlights include extending existing urban library services to rural areas; literacy programs; libraries' roles in national development; financial support; policy and legislation; and education and…

  15. The Phytogeography of New Guinea Solanum (Solanaceae)

    NARCIS (Netherlands)

    Symon, D.E.

    1986-01-01

    The Solanaceae, of which Solanum is the type species, comprise a southern hemisphere family. A general biogeographical introduction is given, with an account of plate tectonics and a discussion of Wallace’s Line and the geographic history of New Guinea. The widely accepted sections of Solanum are di

  16. On the New-Guinea Mammals

    NARCIS (Netherlands)

    Jentink, F.A.

    1907-01-01

    New-Guinea has been called by A. R. Wallace the greatest terra incognita that still remains for the naturalist to explore, and the only region where altogether new and unimagined forms of life may perhaps be found. This he wrote in 1869 and we now living in 1906 can, as a matter of fact, underline t

  17. On Irrotational Flows Beneath Periodic Traveling Equatorial Waves

    Science.gov (United States)

    Quirchmayr, Ronald

    2016-08-01

    We discuss some aspects of the velocity field and particle trajectories beneath periodic traveling equatorial surface waves over a flat bed in a flow with uniform underlying currents. The system under study consists of the governing equations for equatorial ocean waves within a non-inertial frame of reference, where Euler's equation of motion has to be suitably adjusted, in order to account for the influence of the earth's rotation.

  18. Meridional equatorial electrojet current in the American sector

    Directory of Open Access Journals (Sweden)

    R. G. Rastogi

    Full Text Available Huancayo is the only equatorial electrojet station where the daytime increase of horizontal geomagnetic field (H is associated with a simultaneous increase of eastward geomagnetic field (Y. It is shown that during the counter electrojet period when ∆H is negative, ∆Y also becomes negative. Thus, the diurnal variation of ∆Y at equatorial latitudes is suggested to be a constituent part of the equatorial electrojet current system. Solar flares are known to increase the H field at an equatorial station during normal electrojet conditions (nej. At Huancayo, situated north of the magnetic equator, the solar flare effect, during nej, consists of positive impulses in H and Y and negative impulse in Z field. During counter electrojet periods (cej, a solar flare produces a negative impulse in H and Y and a positive impulse in Z at Huancayo. It is concluded that both the zonal and meridional components of the equatorial electrojet in American longitudes, as in Indian longitudes, flows in the same, E region of the ionosphere.

    Key words. Geomagnetism and paleomagnetism (dynamo theories · Ionosphere (equatorial ionosphere; ionosphere disturbances

  19. Eastward traverse of equatorial plasma plumes observed with the Equatorial Atmosphere Radar in Indonesia

    Directory of Open Access Journals (Sweden)

    S. Fukao

    2006-07-01

    Full Text Available The zonal structure of radar backscatter plumes associated with Equatorial Spread F (ESF, probably modulated by atmospheric gravity waves, has been investigated with the Equatorial Atmosphere Radar (EAR in West Sumatra, Indonesia (0.20° S, 100.32° E; dip latitude 10.1° S and the FM-CW ionospheric sounders on the same magnetic meridian as the EAR. The occurrence locations and zonal distances of the ESF plumes were determined with multi-beam observations with the EAR. The ESF plumes drifted eastward while keeping distances of several hundred to a thousand kilometers. Comparing the occurrence of the plumes and the F-layer uplift measured by the FM-CW sounders, plumes were initiated within the scanned area around sunset only, when the F-layer altitude rapidly increased. Therefore, the PreReversal Enhancement (PRE is considered as having a zonal variation with the scales mentioned above, and this variation causes day-to-day variability, which has been studied for a long time. Modulation of the underlying E-region conductivity by gravity waves, which causes inhomogeneous sporadic-E layers, for example, is a likely mechanism to determine the scale of the PRE.

  20. Neotectonics in the northern equatorial Brazilian margin

    Science.gov (United States)

    Rossetti, Dilce F.; Souza, Lena S. B.; Prado, Renato; Elis, Vagner R.

    2012-08-01

    An increasing volume of publications has addressed the role of tectonics in inland areas of northern Brazil during the Neogene and Quaternary, despite its location in a passive margin. Hence, northern South America plate in this time interval might have not been as passive as usually regarded. This proposal needs further support, particularly including field data. In this work, we applied an integrated approach to reveal tectonic structures in Miocene and late Quaternary strata in a coastal area of the Amazonas lowland. The investigation, undertaken in Marajó Island, mouth of the Amazonas River, consisted of shallow sub-surface geophysical data including vertical electric sounding and ground penetrating radar. These methods were combined with morphostructural analysis and sedimentological/stratigraphic data from shallow cores and a few outcrops. The results revealed two stratigraphic units, a lower one with Miocene age, and an upper one of Late Pleistocene-Holocene age. An abundance of faults and folds were recorded in the Miocene deposits and, to a minor extent, in overlying Late Pleistocene-Holocene strata. In addition to characterize these structures, we discuss their origin, considering three potential mechanisms: Andean tectonics, gravity tectonics related to sediment loading in the Amazon Fan, and rifting at the continental margin. Amongst these hypotheses, the most likely is that the faults and folds recorded in Marajó Island reflect tectonics associated with the history of continental rifting that gave rise to the South Atlantic Ocean. This study supports sediment deposition influenced by transpression and transtension associated with strike-slip divergence along the northern Equatorial Brazilian margin in the Miocene and Late Pleistocene-Holocene. This work records tectonic evidence only for the uppermost few ten of meters of this sedimentary succession. However, available geological data indicate a thickness of up to 6 km, which is remarkably thick for

  1. 巴塔(BATA)港简介——赤道几内亚EQUATORIAL GUINEA

    Institute of Scientific and Technical Information of China (English)

    谢文瑞

    2012-01-01

    1.基本概况赤道几内亚是两非一个小国,位于西非几内亚湾,国土分两部分.一部分为巴塔,在1仁洲大陆西部,另一部分为比奥科岛(SLA DE BIOKO)。人口只有约61万.西班牙语为官方语言。原来为两班牙殖民地。首都为MALABO(马拉博),位于比奥科岛北部。赤道几内亚以农林业为主,森林占70%,.原来经济以原小出口为主。现在探明大量的石油资源.闪此现在以石油出口为主要经济支柱.

  2. Master design of Mbini Bridge in Equatorial Guinea%赤道几内亚Mbini大桥总体设计

    Institute of Scientific and Technical Information of China (English)

    李晓霞; 于伟祥

    2009-01-01

    赤道几内亚Mbini桥主桥为120 m+120 m独塔斜拉桥,倒Y型塔,桥宽13 m,肋板式断面,平行钢丝斜拉索.桥位处于Wele河大西洋入海口,防腐、船撞问题是本桥的重点;预应力混凝土主梁在经过多次调索后能够满足规范对C40混凝土全预应力构件的要求,是本设计的一个难点.介绍桥梁构造和计算要点.

  3. Homo infantilis: asimilación y segregación en la política colonial española en Guinea Ecuatorial

    Directory of Open Access Journals (Sweden)

    Sánchez Molina, Raúl

    2002-12-01

    Full Text Available The otherness' ethnocentric construction such as homo infantilis was used by Europeans to justify colonial policies. Spanish colonial policies in Equatorial Guinea provide us a significant context to analyze this specific colonial image's socio-cultural meanings. This article seeks to understand some of this image's political meanings and functions during the Franco colonial period in Equatorial Guinea. This analysis throws some light upon some colonial policies, such as assimilation, implemented by some European countries in Africa as well as some modern social phenomenon such as racism.

    La construcción etnocéntrica del otro como homo infantilis fue utilizada ideológicamente por los europeos para justificar políticas coloniales. El caso particular de la política indígena española en Guinea Ecuatorial nos ofrece un ámbito socio-cultural singular para analizar algunos de los significados y las funciones políticas de esta imagen durante el primer franquismo. Este análisis nos permite profundizar en el alcance de algunas políticas coloniales desarrolladas por los europeos en el continente africano, como la asimilación y el desarrollo de fenómenos sociales modernos como el racismo.

  4. Tibial osteosynthesis in a guinea pig (Cavia porcellus)

    OpenAIRE

    A.S. Macedo; M.A. Goulart; M.M. Alievi; V.S. Mombach; Í.S. Dal-Bó; M.S. Mucillo; R. B. Silva; B.W. Minto

    2015-01-01

    A guinea pig was presented with left pelvic limb lameness after unknown trauma. Radiographs revealed complete oblique diaphyseal fracture of the distal third of the left tibia and fibula. The guinea pig was treated surgically with an intramedullary pin. The day after surgery the guinea pig was using the limb comfortably (grade 1/5 lameness). Callus formation was obtained 21 days after surgery without complications.

  5. Research on the Propagation Acting of the Equatorial Planetary Waves on the Western Equatorial Pacific Warm Pool Heat

    Institute of Scientific and Technical Information of China (English)

    Shi Qiang; Xu Jianping; Zhu Bokang

    2003-01-01

    Based on the long-term buoy data from the Tropical Atmosphere Ocean ( TAO ) array during the TOGA ( Tropical Ocean and Global Atmosphere) Program (1980-1996), the propagation acting of the Equatorial planetary waves on the Western Equatorial Pacific warm pool heat is analyzed. Results show that the zonal heat transmission in the Western Equatorial Pacific takes palace mainly in the subsurface water and spreads eastwards along the thermocline; while the seasonal westward-spreading heat change structure occurs in the mixed layers in the middle and western Pacific. The standing-form transmission in the western Pacific appears in the thermocline layer, while in the eastern pacific, it exists in the mixed layer as well as in the thermocline layer. The standing-form and eastward-spreading sign of zonal heat transmitting in the upper water is predominant and strong, and the westward sign is weak.The component force of Kelvin Equatorial wave pressure runs through the western and eastern Equatorial pacific, and transmits heat energy eastwards. And the heat transmitted by zonal current component occurs mostly in the western Pacific; The heat transmitted by the component force of Rossby wave pressure mainly appears in the eastern and middle areas of the Pacific, while the zonal current component transmitting occurs mainly in the western Pacific; Mixed-Rossby gravity wave's action on the zonal current is stronger than that of the thermocline layer. In the mean state, the standing wave model of Equatorial Pacific up layer ocean temperature confines the transport of western Pacific warm pool heat to the eastern Pacific. Under abnormal conditions, the standing wave model of Equatorial Pacific up layer ocean temperature weakens, the eastwardly transmitting model enhances, and subsequently the El Ni n o event occurs.

  6. Indigenous Cultural Festival In Papua New Guinea

    Institute of Scientific and Technical Information of China (English)

    Sang; Xinhua

    2013-01-01

    <正>In August 2012,I had an opportunity to visit Papua New Guinea,situated in the tropical rainforest areas in the western South Pacific Ocean,adjacent to Indonesia in the west and facing Australia across the Torres Straits in the south.It has over 600 big and small islands and a population of 6.75 million with more than 800 tribes speaking

  7. Elastase-induced emphysema in guinea pigs

    International Nuclear Information System (INIS)

    Pulmonary function changes measured in guinea pigs 4 to 5 wk following intratracheal instillation of crystalline porcine pancreatic elastase resembled comparable changes in humans with moderately severe pulmonary emphysema. Compared with saline-treated controls, elastase-treated animals had increased values for all divisions of lung volume, increased static compliance and prolonged time constants. Since humans with emphysema are especially sensitive to air pollutants, elastase-treated animals may be useful as sensitive animal models in inhalatio toxicology

  8. Anthrax, fairly undetected in Papua New Guinea

    OpenAIRE

    Johnson Makaen; Lydia Tasi

    2015-01-01

    Anthrax is caused by the organism Bacillus anthracis. The organism is globally occurring and epidemics are reported the world over. It is an important infectious disease of domestic animals and can survive harsh conditions that would otherwise be drastic for other microorganisms. To date, no outbreak has been reported in the Pacific Island region except Australia and New Zealand where B. anthracis has been isolated from livestock. Papua New Guinea has had sporadic (reported) instances of anth...

  9. Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini

    CERN Document Server

    Choi, David S; Vasavada, Ashwin R; Simon-Miller, Amy A

    2013-01-01

    We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their interactions with adjacent latitudes. Hot spots are quasi-stable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but diffuse western edges serving as nebulous boundaries with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact...

  10. Occurrence of Equatorial Plasma Bubbles during Intense Magnetic Storms

    Directory of Open Access Journals (Sweden)

    Chao-Song Huang

    2011-01-01

    Full Text Available An important issue in low-latitude ionospheric space weather is how magnetic storms affect the generation of equatorial plasma bubbles. In this study, we present the measurements of the ion density and velocity in the evening equatorial ionosphere by the Defense Meteorological Satellite Program (DMSP satellites during 22 intense magnetic storms. The DMSP measurements show that deep ion density depletions (plasma bubbles are generated after the interplanetary magnetic field (IMF turns southward. The time delay between the IMF southward turning and the first DMSP detection of plasma depletions decreases with the minimum value of the IMF Bz, the maximum value of the interplanetary electric field (IEF Ey, and the magnitude of the Dst index. The results of this study provide strong evidence that penetration electric field associated with southward IMF during the main phase of magnetic storms increases the generation of equatorial plasma bubbles in the evening sector.

  11. Formation of Jets and Equatorial Superrotation on Jupiter

    CERN Document Server

    Schneider, Tapio

    2008-01-01

    The zonal flow in Jupiter's upper troposphere is organized into alternating retrograde and prograde jets, with a prograde (superrotating) jet at the equator. Existing models posit as the driver of the flow either differential radiative heating of the atmosphere or intrinsic heat fluxes emanating from the deep interior; however, they do not reproduce all large-scale features of Jupiter's jets and thermal structure. Here it is shown that the difficulties in accounting for Jupiter's jets and thermal structure resolve if the effects of differential radiative heating and intrinsic heat fluxes are considered together, and if upper-tropospheric dynamics are linked to a magnetohydrodynamic (MHD) drag that acts deep in the atmosphere. Baroclinic eddies generated by differential radiative heating can account for the off-equatorial jets; meridionally propagating equatorial Rossby waves generated by intrinsic convective heat fluxes can account for the equatorial superrotation. The zonal flow extends deeply into the atmos...

  12. Preliminary results of ITEC over an equatorial station

    International Nuclear Information System (INIS)

    Total electron content (TEC) was obtained from bottomside ionograms recorded at an equatorial station (Ouagadougou, 12.4 deg. N, 358.5 deg. E). Variability in TEC obtained in this way (ITEC) was investigated. Diurnal, seasonal and solar cycle effects were observed. Both absolute and relative variability were considered. The results obtained were compared with those of another equatorial station (Ghana, 5.63 deg. N, 359.8 deg. E) where the TEC was obtained by the Faraday rotation technique. The variations in variability at both stations follow the same trend. (author)

  13. Y-chromosomal diversity in the population of Guinea-Bissau: a multiethnic perspective

    Directory of Open Access Journals (Sweden)

    Jobling Mark A

    2007-07-01

    Full Text Available Abstract Background The geographic and ethnolinguistic differentiation of many African Y-chromosomal lineages provides an opportunity to evaluate human migration episodes and admixture processes, in a pan-continental context. The analysis of the paternal genetic structure of Equatorial West Africans carried out to date leaves their origins and relationships unclear, and raises questions about the existence of major demographic phenomena analogous to the large-scale Bantu expansions. To address this, we have analysed the variation of 31 binary and 11 microsatellite markers on the non-recombining portion of the Y chromosome in Guinea-Bissau samples of diverse ethnic affiliations, some not studied before. Results The Guinea-Bissau Y chromosome pool is characterized by low haplogroup diversity (D = 0.470, sd 0.033, with the predominant haplogroup E3a*-M2 shared among the ethnic clusters and reaching a maximum of 82.2% in the Mandenka people. The Felupe-Djola and Papel groups exhibit the highest diversity of lineages and harbor the deep-rooting haplogroups A-M91, E2-M75 and E3*-PN2, typical of Sahel's more central and eastern areas. Their genetic distinction from other groups is statistically significant (P = 0.01 though not attributable to linguistic, geographic or religious criteria. Non sub-Saharan influences were associated with the presence of haplogroup R1b-P25 and particular lineages of E3b1-M78. Conclusion The predominance and high diversity of haplogroup E3a*-M2 suggests a demographic expansion in the equatorial western fringe, possibly supported by a local agricultural center. The paternal pool of the Mandenka and Balanta displays evidence of a particularly marked population growth among the Guineans, possibly reflecting the demographic effects of the agriculturalist lifestyle and their putative relationship to the people that introduced early cultivation practices into West Africa. The paternal background of the Felupe-Djola and Papel

  14. An annotated ornithological bibliography of Guinea-Bissau

    NARCIS (Netherlands)

    Hazevoet, C.J.

    1995-01-01

    Guinea-Bissau, a former Portuguese colony, is a small country (36,125 km²) in West Africa bordered by Senegal in the north and Guinea (Conakry) in the east and south. Little is known about the country’s ornithology and comparatively few papers on its birds have been published. The following is an at

  15. Briti eliit üritas kukutada Ekvatoriaal-Guinea valitsust

    Index Scriptorium Estoniae

    2004-01-01

    Ekvatoriaal-Guineas ja Zimbabwes on vahistatud kümneid inimesi, keda süüdistatakse riigipöördekatses Ekvatoriaal-Guineas. Suurbritannia endise peaministri Margaret Thatcher'i poega Mark Thatcher'it süüdistatakse riigipöördekatse rahastamisele kaasaaitamises

  16. The Guinea Pigs of a Problem-Based Learning Curriculum

    Science.gov (United States)

    Reddy, Sarasvathie; McKenna, Sioux

    2016-01-01

    Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as "Guinea pigs" at the mercy of a curriculum experiment. This article interrogates and problematises the "Guinea pig" identity ascribed to and assumed by the first cohort of…

  17. Crossed Looks: Globalisations and Curriculum in Guinea-Bissau

    Science.gov (United States)

    da Silva, Rui; dos Santos, Júlio Gonçalves; Pacheco, José Augusto

    2015-01-01

    This article focuses on education in Guinea-Bissau in the context of globalisations, examining the concept of globalisation and its relation to education and the curriculum. It focuses on the relatively neglected area of national education policies in Guinea-Bissau, comparing differences and common points of interference/influence of multilateral…

  18. WWF Kikori Catchment Developmental Project, Papua New Guinea orchid survey

    NARCIS (Netherlands)

    Clements, M.A.; Harris, W.K.

    2002-01-01

    The World Wildlife Fund (Kikori Catchment Developmental Project, Papua New Guinea) has commenced field surveys of the Orchidaceae in the Lake Kutabu and Mt Bosavi areas of Papua New Guinea. The main purpose of the survey is to get a more accurate assessment of the orchids in the region. In a previou

  19. Upper ocean circulation modulation by phytoplankton concentration in the Equatorial Pacific and the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Nakamoto, S.; PrasannaKumar, S.; Oberhuber, J.M.; Sammarco, P.; Muneyama, K.; Sato, T.; AjoyKumar, A.; Frouin, R.

    Wind patterns in the equatorial Pacific and Indian oceans are the factors that regulate the chlorophyll pigment distributions in the equatorial region of these oceans. Trade winds and coastline of the Pacific basin supports wave-guide dynamics...

  20. Equatorial ionospheric electrodynamic perturbations during Southern Hemisphere stratospheric warming events

    DEFF Research Database (Denmark)

    Olson, M. E.; Fejer, B. G.; Stolle, Claudia;

    2013-01-01

    We use ground-based and satellite measurements to examine, for the first time, the characteristics of equatorial electrodynamic perturbations measured during the 2002 major and 2010 minor Southern Hemisphere sudden stratospheric warming (SSW) events. Our data suggest the occurrence of enhanced qu...... that showed the fundamentally important role of lunar semidiurnal tidal effects on low latitude electrodynamic perturbations during arctic SSW events....

  1. Exact Nonlinear Internal Equatorial Waves in the f-plane

    Science.gov (United States)

    Hsu, Hung-Chu

    2016-07-01

    We present an explicit exact solution of the nonlinear governing equations for internal geophysical water waves propagating westward above the thermocline in the f-plane approximation near the equator. Moreover, the mass transport velocity induced by this internal equatorial wave is eastward and a westward current occurs in the transition zone between the great depth where the water is still and the thermocline.

  2. Evolution of Ion Clouds in the Equatorial Ionosphere

    Science.gov (United States)

    Petrochuk, Yevgeny; Blaunstein, Nathan; Mishin, Evgeny; Pedersen, Todd; Caton, Ron; Viggiano, Al; Schuman, Nick

    2015-11-01

    We report on the results of 2- and 3-dimentional numerical investigations of the evolution of samarium ion clouds injected in the equatorial ionosphere, alike the recent MOSC experiments. The ambient conditions are described by a standard model of the quiet-time equatorial ionosphere from 90 to 350 km. The altitudinal distribution of the transport processes and ambient electric and magnetic fields is taken into account. The fast process of stratification of ion clouds and breaking into small plasmoids occur only during the late stage of the cloud evolution. The role of the background plasma and its depletion zones formed due to the short-circuiting currents is not as evident as in mid latitudes. It is also revealed that the altitudinal dependence of the diffusion and drift plays a minor role in the cloud evolution at the equator. Likewise, the cloud remains stable with respect to the Raleigh-Taylor and gradient-drift instabilities. These two features are defined by the equatorial near-horizontal magnetic field which leads to a strongly-elongated ellipsoid-like plasma cloud. The critical dip angle separating the stable (equatorial) and unstable (mid-latitude) cloud regimes will be defined in future simulation studies, as well as the dependence on the ambient electric field and neutral wind. 2Space Vehicles Directorate, Air Force Research Laboratory

  3. Signatures of strong geomagnetic storms in the equatorial latitude

    Science.gov (United States)

    Olawepo, A. O.; Adeniyi, J. O.

    2014-04-01

    Ionosonde data from two equatorial stations in the African sector have been used to study the signatures of four strong geomagnetic storms on the height - electron density profiles of the equatorial ionosphere with the objective of investigating the effects and extent of the effects on the three layers of the equatorial ionosphere. The results showed that strong geomagnetic storms produced effects of varying degrees on the three layers of the ionosphere. Effect of strong geomagnetic storms on the lower layers of the equatorial ionosphere can be significant when compared with effect at the F2-layer. Fluctuations in the height of ionization within the E-layer were as much as 0% to +20.7% compared to -12.5% to +8.3% for the F2-layer. The 2007 version of the International Reference Ionosphere, IRI-07 storm-time model reproduced responses at the E-layer but overestimated the observed storm profiles for the F1- and F2-layers.

  4. Climate regulation of fire emissions and deforestation in equatorial Asia

    NARCIS (Netherlands)

    Werf, van der G.R.; Dempewolf, J.; Trigg, S.N.; Randerson, J.T.; Peters, W.

    2008-01-01

    Drainage of peatlands and deforestation have led to large-scale fires in equatorial Asia, affecting regional air quality and global concentrations of greenhouse gases. Here we used several sources of satellite data with biogeochemical and atmospheric modeling to better understand and constrain fire

  5. Observations of ULF wave related equatorial electrojet and density fluctuations

    Science.gov (United States)

    Yizengaw, E.; Zesta, E.; Biouele, C. M.; Moldwin, M. B.; Boudouridis, A.; Damtie, B.; Mebrahtu, A.; Anad, F.; Pfaff, R. F.; Hartinger, M.

    2013-10-01

    We report on Pc5 wave related electric field and vertical drift velocity oscillations at the equator as observed by ground magnetometers for an extended period on 9 August 2008. We show that the magnetometer-estimated equatorial E×B drift oscillates with the same frequency as ULF Pc5 waves, creating significant ionospheric density fluctuations. We also show ionospheric density fluctuations during the period when we observed ULF wave activity. At the same time, we detect the ULF activity on the ground using ground-based magnetometer data from the African Meridian B-field Education and Research (AMBER) and the South American Meridional B-field Array (SAMBA). From space, we use magnetic field observations from the GOES 12 and the Communication/Navigation Outage and Forecast System (C/NOFS) satellites. Upstream solar wind conditions are provided by the ACE spacecraft. We find that the wave power observed on the ground also occurs in the upstream solar wind and in the magnetosphere. All these observations demonstrate that Pc5 waves with a likely driver in the solar wind can penetrate to the equatorial ionosphere and modulate the equatorial electrodynamics. While no direct drift measurements from equatorial radars exist for the 9 August 2008 event, we used JULIA 150 km radar drift velocities observed on 2 May 2010 and found similar fluctuations with the period of 5-8 min, as a means of an independent confirmation of our magnetometer derived drift dynamics.

  6. The equatorial electrojet current modelling from SWARM satellite data

    Science.gov (United States)

    Benaissa, Mahfoud

    2016-07-01

    Equatorial ElectroJet (EEJ) is an intense eastward electric current circulating in the ionospheric magnetic equator band between 100 and 130 km of altitude in E region. These currents vary by day, by season, by solar activity, and also with the main magnetic field of internal origin. The irregularity of the ionosphere has a major impact on the performance of communication systems and navigation (GPS), industry.... Then it becomes necessary study the characteristics of EEJ. In this paper, we present a study of the equatorial electrojet (EEJ) phenomenon along one year (2014) period. In addition, the satellite data used in this study are obtained with SWARM satellite scalar magnetometer data respecting magnetically quiet days with KP < 2. In this paper, we process to separate and extract the electrojet intensity signal from other recorded signal-sources interfering with the main signal and reduce considerably the signal to noise ratio during the SWARM measurements. This pre-processing step allows removing all external contributions in regard to EEJ intensity value. Key words: Ionosphere (Equatorial ionosphere; Electric fields and currents; Equatorial electrojet (EEJ)); SWARM.

  7. Nutrient characteristics of the water masses and their seasonal variability in the eastern equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.; Shetye, S.; Maya, M.V.; Mangala, K.R.; PrasannaKumar, S.

    equatorial counter current and a westward flowing north equatorial current apart from the circulations in the northern Indian ocean. During south west monsoon from May to September, equatorial counter current merges with the easterly flowing south... salinity waters from the Australasian Mediterranean waters (AAMW) under the influence of south equatorial counter current (Sharma et al. 1978). The northern higher salinity water mass is a mixture of the Persian Gulf and Red Sea waters which is found...

  8. Venturing into cashew business in Guinea - Bissau

    OpenAIRE

    Flamengo, Bianca Carvalho Voss Wahnon

    2011-01-01

    A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics This project consists of a business plan for a cashew processing factory in Guinea-Bissau. A company will be created to implement the project with the objective to sell whole white cashews to the general cashew market of the Netherland. To do so the company will have to acquire the ISO 22000 certification and fulfill the Dutch importers qual...

  9. Protection of breastfeeding in Papua New Guinea.

    OpenAIRE

    Friesen, H.; Vince, J; Boas, P.; Danaya, R.

    1999-01-01

    In Papua New Guinea the bottle-feeding of babies has been increasing, predominantly among unemployed women of low educational status. Many women are unaware of their legal right to have breaks at work for the purpose of breastfeeding, and a high proportion of workplaces have no facilities for mothers who wish to breastfeed their children. The laws on the feeding of infants should be updated and implemented, and an effort is needed to explain the benefits of breastfeeding and the rights of wor...

  10. Post-midnight occurrence of equatorial plasma bubbles

    Science.gov (United States)

    Ajith, K. K.; Otsuka, Yuichi; Yamamoto, Mamoru; Yokoyama, Tatsuhiro; Tulasiram, S.

    2016-07-01

    The equatorial plasma bubbles (EPBs)/equatorial spread F (ESF) irregularities are an important topic of space weather interest because of their impact on transionospheric radio communications, satellite-based navigation and augmentation systems. This local plasma depleted structures develop at the bottom side F layer through Rayleigh-Taylor instability and rapidly grow to topside ionosphere via polarization electric fields within them. The steep vertical gradients due to quick loss of bottom side ionization and rapid uplift of equatorial F layer via prereversal enhancement (PRE) of zonal electric field makes the post-sunset hours as the most preferred local time for the formation of EPBs. However, there is a different class of irregularities that occurs during the post-midnight hours of June solstice reported by the previous studies. The occurrence of these post-midnight EPBs maximize during the low solar activity periods. The growth characteristics and the responsible mechanism for the formation of these post-midnight EPBs are not yet understood. Using the rapid beam steering ability of 47 MHz Equatorial Atmosphere Radar (EAR) at Kototabang (0.2°S geographic latitude, 100.3°E geographic longitude, and 10.4°S geomagnetic latitude), Indonesia, the spatial and temporal evolution of equatorial plasma bubbles (EPBs) were examined to classify the evolutionary-type EPBs from those which formed elsewhere and drifted into the field of view of radar. The responsible mechanism for the genesis of summer time post-midnight EPBs were discussed in light of growth rate of Rayleigh-Taylor instability using SAMI2 model.

  11. Case analysis of a role of ENSO in regulating the generation of westerly wind bursts in the Western Equatorial Pacific

    Science.gov (United States)

    Yu, Lisan; Weller, Robert A.; Liu, W. Timothy

    2003-04-01

    This study speculates that the low-frequency ENSO might have a regulating effect on the activity of episodic westerly wind bursts (WWB) in the western equatorial Pacific (WEP) based upon the analysis of two contrasting El Niño-Southern Oscillation (ENSO) phases during the 1996-2000 period and the onset of the 1982 El Niño. It suggests that ∇PWEP, the equatorial sea level pressure (SLP) gradient between 130°E and 160°E, could be a key parameter in relating ENSO to the WWB generation. ∇PWEP is a preconditioning index for the tropical cyclone formation associated with midlatitude atmospheric transient forcing (cold surges). The cyclonic circulation near the equatorial latitudes contributes to prolonged WWB events. ∇PWEP can be regulated by ENSO because the location of the low SLP center, which determines the strength of the ∇PWEP, correlates with the location of the warm water pool, and has an east-west migration in response to the ENSO phases. Through ∇PWEP, the variability of WWB was linked to the ENSO phases. The study finds that ∇PWEP was promoted prior to the 1997 El Niño when the warm pool was large and extended to near the dateline, whereas it was suppressed during the follow on La Niña in 1999/2000 when the warm pool was small and displaced far westward. However, only westerly winds generated in the east of New Guinea could have potential importance to ENSO as the islands over the Indonesian Seas represent a significant blocking to the propagation of a Kelvin wave. It appears that the active WWB in the winter of 1996 were generated on a favorable background conditioned by pre-El Niño state; they facilitated the development of the 1997 El Niño but may not be a sufficient onset mechanism. Further statistical analysis is required to test the veracity of the hypothesis derived from the case analysis of this study.

  12. Effect of antithymocyte serum on the course of chlamydial genital infection in female guinea pigs.

    OpenAIRE

    Rank, R G; Barron, A. L.

    1983-01-01

    The treatment of female guinea pigs, infected in the genital tract with the chlamydial agent of guinea pig inclusion conjunctivitis, with rabbit anti-guinea pig thymocyte serum extended the course of the infection by 20 to 30 days. The rabbit anti-guinea pig thymocyte serum was shown to suppress delayed hypersensitivity responses to the guinea pig inclusion conjunctivitis agent and the contact allergen oxazolone. The appearance of antibody in genital secretions was delayed, but the infection ...

  13. Parasitic zoonoses in Papua New Guinea.

    Science.gov (United States)

    Owen, I L

    2005-03-01

    Relatively few species of zoonotic parasites have been recorded in humans in Papua New Guinea. A greater number of potentially zoonotic species, mostly nematodes, occur in animals but are yet to be reported from humans. Protozoa is the best represented group of those infecting man, with Giardia duodenalis, Cryptosporidium parvum, Cyclospora cayetanesis, Toxoplasma gondii, Sarcocystis spp., Entamoeba polecki, Balantidium coli and, possibly, Blastocystis hominis. The only zoonotic helminths infecting humans include the trematode Paragonimus westermani, the cestodes Hymenolepis nana, H. diminuta and the sparganum larva of Spirometra erinacea, and the nematodes Trichinella papuae and Angiostrongylus cantonensis and, possibly, Ascaris suum. Other groups represented are Acanthocephala (Macracanthorhynchus hirudinaceus)), insects (Chrysomya bezziana, Cimex sp., Ctenocephalides spp.), and mites (Leptotrombidium spp. and, possibly Sarcoptes scabiei, and Demodex sp.). One leech (Phytobdella lineata) may also be considered as being zoonotic. The paucity of zoonotic parasite species can be attributed to long historical isolation of the island of New Guinea and its people, and the absence until recent times of large placental mammals other than pig and dog. Some zoonotic helminths have entered the country with recent importation of domestic animals, in spite of quarantine regulations, and a few more (two cestodes, one nematode and one tick) are poised to enter from neighbouring countries, given the opportunity. Improvement in water supplies, human hygiene and sanitation would reduce the prevalence of many of these parasites, and thorough cooking of meat would lessen the risk of infection by some others. PMID:15831107

  14. Longitudinal Differences of Ionospheric Vertical Density Distribution and Equatorial Electrodynamics

    Science.gov (United States)

    Yizengaw, E.; Zesta, E.; Moldwin, M. B.; Damtie, B.; Mebrahtu, A.; Valledares, C.E.; Pfaff, R. F.

    2012-01-01

    Accurate estimation of global vertical distribution of ionospheric and plasmaspheric density as a function of local time, season, and magnetic activity is required to improve the operation of space-based navigation and communication systems. The vertical density distribution, especially at low and equatorial latitudes, is governed by the equatorial electrodynamics that produces a vertical driving force. The vertical structure of the equatorial density distribution can be observed by using tomographic reconstruction techniques on ground-based global positioning system (GPS) total electron content (TEC). Similarly, the vertical drift, which is one of the driving mechanisms that govern equatorial electrodynamics and strongly affect the structure and dynamics of the ionosphere in the low/midlatitude region, can be estimated using ground magnetometer observations. We present tomographically reconstructed density distribution and the corresponding vertical drifts at two different longitudes: the East African and west South American sectors. Chains of GPS stations in the east African and west South American longitudinal sectors, covering the equatorial anomaly region of meridian approx. 37 deg and 290 deg E, respectively, are used to reconstruct the vertical density distribution. Similarly, magnetometer sites of African Meridian B-field Education and Research (AMBER) and INTERMAGNET for the east African sector and South American Meridional B-field Array (SAMBA) and Low Latitude Ionospheric Sensor Network (LISN) are used to estimate the vertical drift velocity at two distinct longitudes. The comparison between the reconstructed and Jicamarca Incoherent Scatter Radar (ISR) measured density profiles shows excellent agreement, demonstrating the usefulness of tomographic reconstruction technique in providing the vertical density distribution at different longitudes. Similarly, the comparison between magnetometer estimated vertical drift and other independent drift observation

  15. An annotated ornithological bibliography of Guinea-Bissau

    OpenAIRE

    Hazevoet, C.J.

    1995-01-01

    Guinea-Bissau, a former Portuguese colony, is a small country (36,125 km²) in West Africa bordered by Senegal in the north and Guinea (Conakry) in the east and south. Little is known about the country’s ornithology and comparatively few papers on its birds have been published. The following is an attempt at a comprehensive ornithological bibliography of Guinea-Bissau. Much of the results of ornithological work in the country have been published in Portuguese journals and Dutch reports, which ...

  16. Equatorial enhancement of the nighttime OH mesospheric infrared airglow

    Science.gov (United States)

    Baker, D. J.; Thurgood, B. K.; Harrison, W. K.; Mlynczak, M. G.; Russell, J. M.

    2007-05-01

    Global measurements of the hydroxyl mesospheric airglow over an extended period of time have been made possible by the NASA SABER infrared sensor aboard the TIMED satellite which has been functioning since December of 2001. The orbital mission has continued over a significant portion of a solar cycle. Experimental data from SABER for several years have exhibited equatorial enhancements of the nighttime mesospheric OH (Δv=2) airglow layer consistent with the high average diurnal solar flux. The brightening of the OH airglow typically means more H+O3 is being reacted. At both the spring and autumn seasonal equinoxes when the equatorial solar UV irradiance mean is greatest, the peak volume emission rate (VER) of the nighttime Meinel infrared airglow typically appears to be both significantly brighter plus lower in altitude by several kilometres at low latitudes compared with midlatitude findings.

  17. Equatorial enhancement of the nighttime OH mesospheric infrared airglow

    Energy Technology Data Exchange (ETDEWEB)

    Baker, D J [Utah State University, EL-302, Logan, UT 84322-4140 (United States); Thurgood, B K [Utah State University, EL-302, Logan, UT 84322-4140 (United States); Harrison, W K [Utah State University, EL-302, Logan, UT 84322-4140 (United States); Mlynczak, M G [NASA Langley Research Center, Mail Stop 401-B, Hampton, VA 23665-5225 (United States); Russell, J M [Center for Atmospheric Sciences, Hampton University, 23 Tyler Street Hampton, VA 23668 (United States)

    2007-05-15

    Global measurements of the hydroxyl mesospheric airglow over an extended period of time have been made possible by the NASA SABER infrared sensor aboard the TIMED satellite which has been functioning since December of 2001. The orbital mission has continued over a significant portion of a solar cycle. Experimental data from SABER for several years have exhibited equatorial enhancements of the nighttime mesospheric OH ({delta}v=2) airglow layer consistent with the high average diurnal solar flux. The brightening of the OH airglow typically means more H+O{sub 3} is being reacted. At both the spring and autumn seasonal equinoxes when the equatorial solar UV irradiance mean is greatest, the peak volume emission rate (VER) of the nighttime Meinel infrared airglow typically appears to be both significantly brighter plus lower in altitude by several kilometres at low latitudes compared with midlatitude findings.

  18. The dawn enhancement of the equatorial ionospheric vertical plasma drift

    Science.gov (United States)

    Zhang, Ruilong; Liu, Libo; Chen, Yiding; Le, Huijun

    2015-12-01

    Previous studies have reported that a dawn enhancement does not present in the statistical picture of the equatorial ionospheric vertical plasma drift, while it clearly shows in case measurements. In this statistical study, it is the first time to investigate the occurrence of the dawn enhancement in the equatorial ionospheric vertical plasma drift from ROCSAT-1 observations during geomagnetic quiet times. The dawn enhancements occur most frequently in June solstice and least frequently in December solstice. The statistical survey shows that the occurrence depends on the magnetic declination. The enhancement has the strongest amplitude in regions near 320° longitude and peaks during June solstice. The dawn enhancement reaches its peak after the sunrise in conjugated E regions. Furthermore, it is found that the dawn enhancement is closely related to the difference between the sunrise times in the conjugated E regions (sunrise time lag). The dawn enhancement occurs easily in regions with a large sunrise time lag.

  19. Explaining Jupiter's magnetic field and equatorial jet dynamic

    CERN Document Server

    Gastine, T; Duarte, L; Heimpel, M; Becker, A

    2014-01-01

    Spacecraft data reveal a very Earth-like Jovian magnetic field. This is surprising since numerical simulations have shown that the vastly different interiors of terrestrial and gas planets can strongly affect the internal dynamo process. Here we present the first numerical dynamo that manages to match the structure and strength of the observed magnetic field by embracing the newest models for Jupiter's interior. Simulated dynamo action primarily occurs in the deep high electrical conductivity region while zonal flows are dynamically constrained to a strong equatorial jet in the outer envelope of low conductivity. Our model reproduces the structure and strength of the observed global magnetic field and predicts that secondary dynamo action associated to the equatorial jet produces banded magnetic features likely observable by the Juno mission. Secular variation in our model scales to about 2000 nT per year and should also be observable during the one year nominal mission duration.

  20. Ongoing Analysis of Jupiter's Equatorial Hotspots and Plumes from Cassini

    Science.gov (United States)

    Choi, D. S.; Showmwn, A. P.; Vasavada, A. R.; Simon-Miller, A. A.

    2012-01-01

    We present updated results from our ongoing analysis of Cassini observations of Jupiter's equatorial meteorology. For two months preceding the spacecraft's closest approach of the planet, the ISS instrument onboard Cassini regularly imaged the atmosphere of Jupiter. We created time-lapse movies from this period that show the complex activity and interactions of the equatorial atmosphere. During this period, hot spots exhibited significant variations in size and shape over timescales of days and weeks. Some of these changes appear to be a result of interactions with passing vortex systems in adjacent latitudes. Strong anticyclonic gyres to the southeast of the dark areas converge with flow from the west and appear to circulate into a hot spot at its southwestern corner.

  1. Industrial concessions, fires and air pollution in Equatorial Asia

    Science.gov (United States)

    Spracklen, D. V.; Reddington, C. L.; Gaveau, D. L. A.

    2015-09-01

    Forest and peatland fires in Indonesia emit large quantities of smoke leading to poor air quality across Equatorial Asia. Marlier et al (2015 Environ. Res. Lett. 10 085005) explore the contribution of fires occurring on oil palm, timber (wood pulp and paper) and natural forest logging concessions to smoke emissions and exposure of human populations to the resulting air pollution. They find that one third of the population exposure to smoke across Equatorial Asia is caused by fires in oil palm and timber concessions in Sumatra and Kalimantan. Logging concessions have substantially lower fire emissions, and contribute less to air quality degradation. This represents a compelling justification to prevent reclassification of logging concessions into oil palm or timber concessions after logging. This can be achieved by including logged forests in the Indonesian moratorium on new plantations in forested areas.

  2. Air-sea interaction patterns in the equatorial Pacific

    OpenAIRE

    Kent, John E.

    1993-01-01

    We have investigated air-sea interaction patterns in the equatorial Pacific during the 1991-1992 El Nino/Southern Oscillation (ENSO) event. Our study focused on the identification of spatial and temporal relationships between sea surface temperatures, subsurface temperatures, and winds. These relationships were examined using time series and statistical analyses of atmosphere and ocean data from the moored buoys of the Tropical Oceans-Global Atmosphere (TOGA) program. Our results strongly sug...

  3. Saturn's equatorial jet structure from Cassini/ISS

    Science.gov (United States)

    García-Melendo, Enrique; Legarreta, Jon; Sánchez-Lavega, Agustín.; Pérez-Hoyos, Santiago; Hueso, Ricardo

    2010-05-01

    Detailed wind observations of the equatorial regions of the gaseous giant planets, Jupiter and Saturn, are crucial for understanding the basic problem of the global circulation and obtaining new detailed information on atmospheric phenomena. In this work we present high resolution data of Saturn's equatorial region wind profile from Cassini/ISS images. To retrieve wind measurements we applied an automatic cross correlator to image pairs taken by Cassini/ISS with the MT1, MT2, MT3 filters centred at the respective three methane absorbing bands of 619nm, 727nm, and 889nm, and with the adjacent continuum CB1, CB2, and CB3 filters. We obtained a complete high resolution coverage of Saturn's wind profile in the equatorial region. The equatorial jet displays an overall symmetric structure similar to that shown the by same region in Jupiter. This result suggests that, in accordance to some of the latest compressible atmosphere computer models, probably global winds in gaseous giants are deeply rooted in the molecular hydrogen layer. Wind profiles in the methane absorbing bands show the effect of strong vertical shear, ~40m/s per scale height, confirming previous results and an important decay in the wind intensity since the Voyager era (~100 m/s in the continuum and ~200 m/s in the methane absorbing band). We also report the discovery of a new feature, a very strong and narrow jet on the equator, about only 5 degrees wide, that despite the vertical shear maintains its intensity (~420 m/s) in both, the continuum and methane absorbing band filters. Acknowledgements: Work supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07.

  4. Recurring Slope Lineae in Mid-Latitude and Equatorial Mars

    Science.gov (United States)

    McEwen, A. S.; Dundas, C. M.; Mattson, S.; Toigo, A. D.; Ojha, L.; Wray, J. J.; Chojnacki, M.; Byrne, S.; Murchie, S. L.; Thomas, N.

    2013-12-01

    A key to potential present-day habitability of Mars is the presence of liquid H2O (water). Recurring slope lineae (RSL) could be evidence for the seasonal flow of water on relatively warm slopes. RSL are narrow (250 K to >300 K. In the past year we have monitored active RSL in equatorial (0°-15°S) regions of Mars, especially in the deep canyons of Valles Marineris. They are especially active on north-facing slopes in northern summer and spring and on south-facing slopes in southern spring and summer, following the most normal solar incidence angles on these steep slopes. However, predicted peak temperatures for north-facing slopes are nearly constant throughout the Martian year because orbital periapse occurs near the southern summer solstice. Although warm temperatures and steep low-albedo slopes are required, some additional effect besides temperature may serve to trigger and stop RSL activity. Seasonal variation in the atmospheric column abundance of water does not match the RSL activity. Although seasonal melting of shallow ice could explain the mid-latitude RSL, the equatorial activity requires a different explanation, perhaps migration of briny groundwater. To explain RSL flow lengths, exceeding 1 km in Valles Marineris, the water is likely to be salty. Several RSL attributes are not yet understood: (1) the relation between apparent RSL activity and dustiness of the atmosphere; (2) salt composition and concentration; (3) variability in RSL activity from year to year; (4) seasonal activity on north-facing equatorial slopes in spite of little change in temperature; and (5) temporal changes in the color properties of fans where RSL terminate. Continued orbital monitoring, laboratory experiments, and future orbital and landed exploration with new measurement types are needed. Equatorial water activity, if confirmed, creates new exploration opportunities and challenges. RSL >1 km long near boundary between Eos and Capri Chasmata of Valles Marineris, Mars.

  5. Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini

    Science.gov (United States)

    Choi, David Sanghun; Showman, Adam P.; Vasavada, Ashwin R.; Simon-Miller, Amy A.

    2013-01-01

    We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their interactions with adjacent latitudes. Hot spots are relatively cloud-free regions that emit strongly at 5 lm; improved knowledge of these features is crucial for fully understanding Galileo probe measurements taken during its descent through one. Hot spots are quasistable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but diffuse western edges serving as nebulous boundaries with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-like 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. These clouds travel at 150-200 m/s, much faster than the 100 m/s hot spot and plume drift speed. This raises the possibility that the scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. Most previously published zonal wind profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby wave controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed.

  6. Scaling of Off-Equatorial Jets in Giant Planet Atmospheres

    OpenAIRE

    Liu, Junjun; Schneider, Tapio

    2015-01-01

    In the off-equatorial region of Jupiter’s and Saturn’s atmospheres, baroclinic eddies transport angular momentum out of retrograde and into prograde jets. In a statistically steady state, this angular momentum transfer by eddies must be balanced by dissipation, likely produced by magnetohydrodynamic (MHD) drag in the planetary interior. This paper examines systematically how an idealized representation of this drag in a general circulation model (GCM) of the upper atmosphere of giant planets ...

  7. Equatorial wave analysis from SABER and ECMWF temperatures

    Directory of Open Access Journals (Sweden)

    M. Ern

    2008-02-01

    Full Text Available Equatorial planetary scale wave modes such as Kelvin waves or Rossby-gravity waves are excited by convective processes in the troposphere. In this paper an analysis for these and other equatorial wave modes is carried out with special focus on the stratosphere using temperature data from the SABER satellite instrument as well as ECMWF temperatures. Space-time spectra of symmetric and antisymmetric spectral power are derived to separate the different equatorial wave types and the contribution of gravity waves is determined from the spectral background of the space-time spectra.

    Both gravity waves and equatorial planetary scale wave modes are main drivers of the quasi-biennial oscillation (QBO in the stratosphere. Temperature variances attributed to the different wave types are calculated for the period from February 2002 until March 2006 and compared to previous findings. A comparison between SABER and ECMWF wave analyses shows that in the lower stratosphere SABER and ECMWF spectra and temperature variances agree remarkably well while in the upper stratosphere ECMWF tends to overestimate Kelvin wave components. Gravity wave variances are partly reproduced by ECMWF but have a significant low-bias. For the examples of a QBO westerly phase (October–December 2004 and a QBO easterly phase (November/December 2005, period of the SCOUT-O3 tropical aircraft campaign in Darwin/Australia in the lower stratosphere we find qualitatively good agreement between SABER and ECMWF in the longitude-time distribution of Kelvin, Rossby (n=1, and Rossby-gravity waves.

  8. Modelling of the ionosphere by neural network for equatorial SBAS

    OpenAIRE

    Desert, Thibault; Authié, Thierry; Trilles, Sébastien

    2015-01-01

    International audience; The estimation of the ionosphere delay and associated confidence interval constitutes the major issue to reach APV1 availability performance level for single frequency SBAS above the equatorial area.The ionosphere is a complex physical system which dynamics is particularly disturbed at the Geomagnetic Equator while mid-latitude regions are quieter. Classical methods to compute ionosphere delays, such as those implemented in EGNOS and the WAAS, are specific to a smooth ...

  9. Solar cycle signatures in the NCEP equatorial annual oscillation

    OpenAIRE

    H. G. Mayr; Mengel, J. G.; F. T. Huang; Nash, E. R.

    2009-01-01

    Our analysis of temperature and zonal wind data (1958 to 2006) from the National Center for Atmospheric Research (NCAR) reanalysis (Re-1), supplied by the National Centers for Environmental Prediction (NCEP), shows that the hemispherically symmetric 12-month equatorial annual oscillation (EAO) contains spectral signatures with periods around 11 years. Moving windows of 44 years show that, below 20 km, the 11-year modulation of the EAO is phase locked to the solar cycle (SC). The spectral feat...

  10. Productivity control of fine particle transport to equatorial Pacific sediment

    Science.gov (United States)

    Thomas, E.; Turekian, K. K.; Wei, K.-Y.

    2000-09-01

    Accumulation rates of 3He (from cosmic dust), 230Th (produced in the water column), barite (produced in the water column during decay of organic matter), and Fe and Ti (arriving with wind-borne dust) all are positively correlated in an equatorial Pacific core (TT013-PC72; 01.1°N, 139.4°W; water depth 4298 m). These accumulation rates are also positively correlated with the accumulation rates of noncarbonate material. They are not significantly correlated to the mass accumulation rate of carbonate, which makes up the bulk of the sediment. The fluctuations in accumulation rates of these various components from different sources thus must result from variations in some process within the oceans and not from variations in their original sources. Sediment focusing by oceanic bottom currents has been proposed as this process [Marcantonio et al., 1996]. We argue that the variations in the accumulation rates of all these components are dominantly linked to changes in productivity and particle scavenging (3He, 230Th, Fe, Ti) by fresh phytoplankton detritus (which delivers Ba upon its decay) in the equatorial Pacific upwelling region. We speculate that as equatorial Pacific productivity is a major component of global oceanic productivity, its variations over time might be reflected in variations in atmospheric levels of methanesulfonic acid (an atmospheric reaction product of dimethyl sulfide, which is produced by oceanic phytoplankton) and recorded in Antarctic ice cores.

  11. Limits to solar cycle predictability: Cross-equatorial flux plumes

    CERN Document Server

    Cameron, R H; Jiang, J; Iş\\ik, E; Schmitt, D; Schüssler, M

    2013-01-01

    Within the Babcock-Leighton framework for the solar dynamo, the strength of a cycle is expected to depend on the strength of the dipole moment or net hemispheric flux during the preceding minimum, which depends on how much flux was present in each hemisphere at the start of the previous cycle and how much net magnetic flux was transported across the equator during the cycle. Some of this transport is associated with the random walk of magnetic flux tubes subject to granular and supergranular buffeting, some of it is due to the advection caused by systematic cross-equatorial flows such as those associated with the inflows into active regions, and some crosses the equator during the emergence process. We aim to determine how much of the cross-equatorial transport is due to small-scale disorganized motions (treated as diffusion) compared with other processes such as emergence flux across the equator. We measure the cross-equatorial flux transport using Kitt Peak synoptic magnetograms, estimating both the total a...

  12. Fake anti-malarials: start with the facts.

    Science.gov (United States)

    Kaur, Harparkash; Clarke, Siȃn; Lalani, Mirza; Phanouvong, Souly; Guérin, Philippe; McLoughlin, Andrew; Wilson, Benjamin K; Deats, Michael; Plançon, Aline; Hopkins, Heidi; Miranda, Debora; Schellenberg, David

    2016-02-13

    This meeting report presents the key findings and discussion points of a 1-day meeting entitled 'Fake anti-malarials: start with the facts' held on 28th May 2015, in Geneva, Switzerland, to disseminate the findings of the artemisinin combination therapy consortium's drug quality programme. The teams purchased over 10,000 samples, using representative sampling approaches, from six malaria endemic countries: Equatorial Guinea (Bioko Island), Cambodia, Ghana, Nigeria, Rwanda and Tanzania. Laboratory analyses of these samples showed that falsified anti-malarials (fact that the WHO has urged regulatory authorities in malaria-endemic countries to take measures to halt the production and marketing of these oral monotherapies since 2007. This report summarizes the presentations that reviewed the public health impact of falsified and substandard drugs, sampling strategies, techniques for drug quality analysis, approaches to strengthen health systems capacity for the surveillance of drug quality, and the ensuing discussion points from the dissemination meeting.

  13. The genus Freycinetia (Pandanaceae) in New Guinea (Part 4)

    NARCIS (Netherlands)

    Huynh, Kim-Lang

    2002-01-01

    Seventeen new species of Freycinetia Gaudich. are described from groups of islands of New Guinea: Freycinetia admiraltiensis, F. amoena, F. formosula, F. granulata, F. lanceolata, F. nakanaiensis, F. novobritannica (Bismarck Archipelago), F. relegata, F. rossellana (Louisiade Archipelago), F. angust

  14. Anthrax, fairly undetected in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Johnson Makaen

    2015-07-01

    Full Text Available Anthrax is caused by the organism Bacillus anthracis. The organism is globally occurring and epidemics are reported the world over. It is an important infectious disease of domestic animals and can survive harsh conditions that would otherwise be drastic for other microorganisms. To date, no outbreak has been reported in the Pacific Island region except Australia and New Zealand where B. anthracis has been isolated from livestock. Papua New Guinea has had sporadic (reported instances of anthrax outbreak, but has not been scientifically established. It is still unclear if the anthrax causing organism is present in the environment or wildlife in the country. It remains to be so until scientific evidence becomes available. This article aims to review scientific evidence of anthrax in the country.

  15. Cholera risk factors, Papua New Guinea, 2010

    Directory of Open Access Journals (Sweden)

    Rosewell Alexander

    2012-11-01

    Full Text Available Abstract Background Cholera is newly emergent in Papua New Guinea but may soon become endemic. Identifying the risk factors for cholera provides evidence for targeted prevention and control measures. Methods We conducted a hospital-based case–control study to identify cholera risk factors. Using stool culture as the standard, we evaluated a cholera point of care test in the field. Results 176 participants were recruited: 54 cases and 122 controls. Independent risk factors for cholera were: being over 20 years of age (aOR 2.5; 95%CI 1.1, 5.4, defecating in the open air (or river (aOR 4.5; 95% CI 1.4, 14.4 and knowing someone who travelled to a cholera affected area (aOR 4.1; 95%CI 1.6, 10.7; while the availability of soap for handwashing at home was protective (aOR 0.41; 95%CI 0.19, 0.87. Those reporting access to a piped water distribution system in the home were twice as likely to report the availability of soap for handwashing. The sensitivity and specificity of the rapid test were 72% (95% CI 47–90 and 71% (95%CI 44–90%. Conclusions Improving population access to the piped water distribution system and sanitation will likely reduce transmission by enabling enhanced hygiene and limiting the contamination of water sources. The One step V. cholerae O1/O139 Antigen Test is of limited utility for clinical decision making in a hospital setting with access to traditional laboratory methods. Settlement dwellers and mobile populations of all age groups should be targeted for interventions in Papua New Guinea.

  16. Ascitic starch phagocytosis in experimental guinea-pig peritonitis.

    OpenAIRE

    Grant, J. B.; Davies, J. D.

    1981-01-01

    Phagocytosis of starch granules in ascitic fluid was sought in guinea-pigs 1 to 10 days after i.p. injection of a suspension of starch powder. Starch phagocytosis occurred in 75.9% of control animals with free peritoneal fluid. It probably represents a nonspecific reaction to the particulate nature of starch granules. Guinea-pigs sensitized to starch by nuchal inoculation of an emulsion of Freund's adjuvant and starch showed no increase in frequency or intensity of ascitic starch phagocytosis...

  17. How much does malaria vector control quality matter: the epidemiological impact of holed nets and inadequate indoor residual spraying.

    Directory of Open Access Journals (Sweden)

    Andrea M Rehman

    Full Text Available BACKGROUND: Insecticide treated nets (ITN and indoor residual spraying (IRS are the two pillars of malaria vector control in Africa, but both interventions are beset by quality and coverage concerns. Data from three control programs were used to investigate the impact of: 1 the physical deterioration of ITNs, and 2 inadequate IRS spray coverage, on their respective protective effectiveness. METHODS: Malaria indicator surveys were carried out in 2009 and 2010 in Bioko Island, mainland Equatorial Guinea and Malawi to monitor infection with P. falciparum in children, mosquito net use, net condition and spray status of houses. Nets were classified by their condition. The association between infection and quality and coverage of interventions was investigated. RESULTS: There was reduced odds of infection with P. falciparum in children sleeping under ITNs that were intact (Odds ratio (OR: 0.65, 95% CI: 0.55-0.77 and OR: 0.81, 95% CI: 0.56-1.18 in Equatorial Guinea and in Malawi respectively, but the protective effect became less with increasingly worse condition of the net. There was evidence for a linear trend in infection per category increase in deterioration of nets. In Equatorial Guinea IRS offered protection to those in sprayed and unsprayed houses alike when neighbourhood spray coverage was high (≥80% compared to those living in areas of low IRS coverage (<20%, regardless of whether the house they lived in was sprayed or not (adjusted OR = 0.54, 95% CI 0.33-0.89. ITNs provided only personal protection, offering no protection to non users. Although similar effects were seen in Malawi, the evidence was much weaker than in Equatorial Guinea. CONCLUSIONS: Universal coverage strategies should consider policies for repair and replacement of holed nets and promote the care of nets by their owners. IRS programs should ensure high spray coverage since inadequate coverage gives little or no protection at all.

  18. Biogeography and potential exchanges among the atlantic Equatorial belt cold-seep faunas.

    Directory of Open Access Journals (Sweden)

    Karine Olu

    Full Text Available Like hydrothermal vents along oceanic ridges, cold seeps are patchy and isolated ecosystems along continental margins, extending from bathyal to abyssal depths. The Atlantic Equatorial Belt (AEB, from the Gulf of Mexico to the Gulf of Guinea, was one focus of the Census of Marine Life ChEss (Chemosynthetic Ecosystems program to study biogeography of seep and vent fauna. We present a review and analysis of collections from five seep regions along the AEB: the Gulf of Mexico where extensive faunal sampling has been conducted from 400 to 3300 m, the Barbados accretionary prism, the Blake ridge diapir, and in the Eastern Atlantic from the Congo and Gabon margins and the recently explored Nigeria margin. Of the 72 taxa identified at the species level, a total of 9 species or species complexes are identified as amphi-Atlantic. Similarity analyses based on both Bray Curtis and Hellinger distances among 9 faunal collections, and principal component analysis based on presence/absence of megafauna species at these sites, suggest that within the AEB seep megafauna community structure is influenced primarily by depth rather than by geographic distance. Depth segregation is observed between 1000 and 2000 m, with the middle slope sites either grouped with those deeper than 2000 m or with the shallower sites. The highest level of community similarity was found between the seeps of the Florida escarpment and Congo margin. In the western Atlantic, the highest degree of similarity is observed between the shallowest sites of the Barbados prism and of the Louisiana slope. The high number of amphi-atlantic cold-seep species that do not cluster according to biogeographic regions, and the importance of depth in structuring AEB cold-seep communities are the major conclusions of this study. The hydrothermal vent sites along the Mid Atlantic Ridge (MAR did not appear as "stepping stones" for dispersal of the AEB seep fauna, however, the south MAR and off axis regions

  19. Ocean Pollution as a Result of Onshore Offshore Petroleum Activities in the African Gulf of Guinea Region

    Science.gov (United States)

    Abubakar, B.

    2007-05-01

    The Gulf of Guinea region is located on the Atlantic side of Africa; the sub region has a total population of approximately 190million people. It comprises of five different countries and their territorial waters, which are as follows: Nigeria, Sao Tome & Principe, Equatorial Guinea, Gabon and Cameroon. The sub region is blessed with so many types of natural resources ranging from petroleum, Natural gas, Bitumen, Uranium Diamond and Gold to mention but a few. However the region since the last two decades started attracting the World's attention as a result of the continuous increasing discoveries of new oil fields on both its on shores and off shores. In view of this extra ordinary increasing discoveries of new oil fields in the region, the Gulf of Guinea has become a "Gold rush" to the oil companies and it has so far attracted almost all the top oil firms in the world including; Exxon Mobil, Shell, Total, Texaco, Agip, Chevron, Slumberger, Stat Oil and Conoco Phillips among many other oil giants. In the more recent time even the U.S. Marine Corp have stationed their War Ship in the territorial waters of the Gulf in the name of providing protection to the "Liquid Gold" (Petroleum) underlying the beneath of the region. OIL ACTIVITIES AND ITS ASSOCIATED PROBLEMS IN THE GULF OF GUINEA As a result of the geometrically increasing oil activities in the region ranging from Drilling, Gas flaring, Bunkering and Exploration activities, there was increase in the general pollution of the region. For example recent reports released in June, 2005 by the internationally renown nongovernmental organization on environmental pollution the Netherlands based Climate Justice programme and the Nigeria's Environmental Rights Action, Under the aegis of friends of the Earth, had it that the region is ranked top on the world's total flare with Nigeria along accounting for 16 percent of the world's total flare. Another example is the increasing cases of oil spillages leading to the

  20. The Guinea-Bissau family of Mycobacterium tuberculosis complex revisited.

    Directory of Open Access Journals (Sweden)

    Ramona Groenheit

    Full Text Available The Guinea-Bissau family of strains is a unique group of the Mycobacterium tuberculosis complex that, although genotypically closely related, phenotypically demonstrates considerable heterogeneity. We have investigated 414 M. tuberculosis complex strains collected in Guinea-Bissau between 1989 and 2008 in order to further characterize the Guinea-Bissau family of strains. To determine the strain lineages present in the study sample, binary outcomes of spoligotyping were compared with spoligotypes existing in the international database SITVIT2. The major circulating M. tuberculosis clades ranked in the following order: AFRI (n = 195, 47.10%, Latin-American-Mediterranean (LAM (n = 75, 18.12%, ill-defined T clade (n = 53, 12.8%, Haarlem (n = 37, 8.85%, East-African-Indian (EAI (n = 25, 6.04%, Unknown (n = 12, 2.87%, Beijing (n = 7, 1.68%, X clade (n = 4, 0.96%, Manu (n = 4, 0.97%, CAS (n = 2, 0.48%. Two strains of the LAM clade isolated in 2007 belonged to the Cameroon family (SIT61. All AFRI isolates except one belonged to the Guinea-Bissau family, i.e. they have an AFRI_1 spoligotype pattern, they have a distinct RFLP pattern with low numbers of IS6110 insertions, and they lack the regions of difference RD7, RD8, RD9 and RD10, RD701 and RD702. This profile classifies the Guinea-Bissau family, irrespective of phenotypic biovar, as part of the M. africanum West African 2 lineage, or the AFRI_1 sublineage according to the spoligtyping nomenclature. Guinea-Bissau family strains display a variation of biochemical traits classically used to differentiate M. tuberculosis from M. bovis. Yet, the differential expression of these biochemical traits was not related to any genes so far investigated (narGHJI and pncA. Guinea-Bissau has the highest prevalence of M. africanum recorded in the African continent, and the Guinea-Bissau family shows a high phylogeographical specificity for Western Africa, with Guinea

  1. A multi-model approach to the Atlantic Equatorial mode : impact on the West African monsoon

    OpenAIRE

    Losada, T.; Rodriguez-Fonseca, B.; Janicot, Serge; Gervois, S.; Chauvin, F.; Ruti, P.

    2010-01-01

    This paper is focused on the West African anomalous precipitation response to an Atlantic Equatorial mode whose origin, development and damping resembles the observed one during the last decades of the XXth century. In the framework of the AMMA-EU project, this paper analyses the atmospheric response to the Equatorial mode using a multimodel approach with an ensemble of integrations from 4 AGCMs under a time varying Equatorial SST mode. The Guinean Gulf precipitation, which together with the ...

  2. Structures of Equatorial Envelope Rossby Wave Under a Generalized External Forcing

    Institute of Scientific and Technical Information of China (English)

    FU Zun-Tao; LIU Shi-Da; LIU Shi-Kuo

    2004-01-01

    The cubic nonlinear Schrodinger (NLS for short) equation with a generalized external heating source is derived for large amplitude equatorial envelope Rossby wave in a shear flow. And then various periodic structures for these equatorial envelope Rossby waves are obtained with the help of a new transformation, Jacobi elliptic functions,and elliptic equation. It is shown that different types of resonant phase-locked diabatic heating play different roles in structures of equatorial envelope Rossby wave.

  3. Structures of Equatorial Envelope Rossby Wave Under a Generalized External Forcing

    Institute of Scientific and Technical Information of China (English)

    FUZun-Tao; LIUShi-Da; LIUShi-Kuo

    2004-01-01

    The cubic nonlinear Schroedinger (NLS for short) equation with a generalized external heating source is derived for large amplitude equatorial envelope Rossby wave in a shear flow. And then various periodic structures for these equatorial cnvelope Rossby waves are obtained with the help of a new transformation, Jacobi elliptic functions,and elliptic equation. It is shown that different types of resonant phase-locked diabatic heating play different roles in structures of equatorial envelope Rossby wave.

  4. New Measurements Of Jupiter's Equatorial Region In Visible Wavelengths

    Science.gov (United States)

    Rojas, Jose; Arregi, J.; García-Melendo, E.; Barrado-Izagirre, N.; Hueso, R.; Gómez-Forrellad, J. M.; Pérez-Hoyos, S.; Sanz-Requena, J. F.; Sánchez-Lavega, A.

    2010-10-01

    We have studied the equatorial region of Jupiter, between 15ºS and 15ºN, on Cassini ISS images obtained during the Jupiter flyby at the end of 2000 and on HST images acquired in May and July 2008. We have found significant longitudinal variations in the intensity of the 6ºN eastward jet, up to 60 m s-1 in Cassini and HST observations. In the HST case we found that these longitudinal variations are associated to different cloud morphology. Photometric and radiative transfer analysis of the cloud features used as tracers in HST images shows that there is only a small height difference, no larger than 0.5 - 1 scale heights at most, between the slow ( 100 m s-1) and fast ( 150 m s-1) moving features. This suggests that speed variability at 6ºN is not dominated by vertical wind shears and we propose that Rossby wave activity is the responsible for the zonal variability. After removing this variability we found that Jupiter's equatorial jet is actually symmetric relative to the equator with two peaks of 140 - 150 m s-1 located at latitudes 6ºN and 6ºS and at a similar pressure level. We also studied a large, long-lived feature called the White Spot (WS) located at 6ºS that turns to form and desapear. The internal flow field in the White Spot indicates that it is a weakly rotating quasi-equatorial anticyclone relative to the ambient meridionally sheared flow. Acknowledgements: This work was supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07.

  5. Equatorial anisotropy of the Earth's inner-inner core

    Science.gov (United States)

    Song, X.; Wang, T.; Xia, H.

    2015-12-01

    Anisotropy of Earth's inner core is a key to understand its evolution and the generation of the Earth's magnetic field. All the previous inner core anisotropy models have assumed a cylindrical anisotropy with the symmetry axis parallel (or nearly parallel) to the Earth's spin axis. However, we have recently found that the fast axis in the inner part of the inner core is close to the equator from inner-core waves extracted from earthquake coda. We obtained inner core phases, PKIIKP2 and PKIKP2 (round-trip phases between the station and its antipode that passes straight through the center of the Earth and that is reflected from the inner core boundary, respectively), from stackings of autocorrelations of the coda of large earthquakes (10,000~40,000 s after Mw>=7.0 earthquakes) at seismic station clusters around the world. We observed large variation of up to 10 s along equatorial paths in the differential travel times PKIIKP2 - PKIKP2, which are sensitive to inner-core structure. The observations can be explained by a cylindrical anisotropy in the inner inner core (IIC) (with a radius of slightly less than half the inner core radius) that has a fast axis aligned near the equator and a cylindrical anisotropy in the outer inner core (OIC) that has a fast axis along the north-south direction. We have obtained more observations using the combination of autocorrelations and cross-correlations at low-latitude station arrays. The results further confirm that the IIC has an equatorial anisotropy and a pattern different from the OIC. The equatorial fast axis of the IIC is near the Central America and the Southeast Asia. The drastic change in the fast axis and the form of anisotropy from the IIC to the OIC may suggest a phase change of the iron or a major shift in the crystallization and deformation during the formation and growth of the inner core.

  6. Variability in equatorial B0 and B1

    International Nuclear Information System (INIS)

    Variability of ionospheric profile parameters B0 and B1, below the F2 peak is investigated for an equatorial station at two levels of solar activities. The whole 24 hours of the day and the four seasons of the year are covered. Absolute and relative variability indices were utilized in the study. Some evidences of correlations of variability index and profiles parameters were observed. Daytime values of relative variability in B1 at solar minimum were found to be greater than those of solar maximum. (author)

  7. Mismo field experiment in the equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Masumoto, Y.; Kuroda, Y.; Katsumata, M.; Mizuno, K.; Takayabu, Y.N.; Yoshizaki, M.; Shareef, A.; Fujiyoshi, Y.; McPhaden, M.J.; Murty, V.S.N.; Shirooka, R.; Yasunaga, K.; Yamada, H.; Sato, N.; Ushiyama, T.; Moteki, Q.; Seiki, A.; Fujita, M.; Ando, K.; Hase, H.; Ueki, I.; Horii, T.; Yokoyama, C.; Miyakawa, T.

    are shown in Fig. 7 with the time series of SST. Daily mean SST increased from a minimum value (28.3°C) on 28 October to the highest value (29.4°C) on 9 November. The diurnal cycle of SST is particu- larly dominant during 30 October–15 November, and skin... sensor (roughly 5-m depth from the sea surface, black line) and IsAr system (skin surface, green line). red line indicates daily mean value of intake sst. 1897december 2008AmerIcAN meTeOrOLOGIcAL SOcIeTY | The relationship between the equatorial Rossby...

  8. Ionospheric scintillations associated with equatorial E-region

    Science.gov (United States)

    Chandra, H.; Vats, H. O.; Sethia, G.; Deshpande, M. R.; Rastogi, R. G.; Sastri, J. H.

    1978-01-01

    Amplitude scintillations at 40, 140, and 360 MHz recorded at an equatorial station Ootacamund (dip 4 deg N) during the ATS-6 phase II and the ionograms at a nearby station Kodaikanal (dip 3.5 deg N) are examined for the scintillation activity. Various sporadic E events, but not the Es-q, are associated with intense daytime scintillations. There are no scintillations at times of normal E-layer or cusp type of Es. Scintillations are also present at times of night Es.

  9. Climatology of early night equatorial spread F over Jicamarca

    OpenAIRE

    Chapagain, N. P.; Fejer, Bela G.

    2009-01-01

    [1] We use radar observations from 1996 to 2006 to study the climatology of postsunset equatorial 3-m spread F irregularities over Jicamarca during all seasons. We show that the spread F onset times do not change with solar flux and that their onset heights, which occur near the altitude of the evening F region velocity vortex, increase linearly from about 260 to 400 km from solar minimum to solar maximum. Higher onset heights generally lead to stronger radar echoes. During the equinox, sprea...

  10. Seasonal variability of the bifurcation of the North Equatorial Current

    Institute of Scientific and Technical Information of China (English)

    JU Qiang-chang; JIANG Song; TIAN Ji-wei; KONG Ling-hai; NI Guo-xi

    2013-01-01

    Seasonal variability of the bifurcation of the North Equatorial Current (NEC) is studied by constructing the analytic solution for the time-dependent horizontal linear shallow water quasi-geostrophic equations.Using the Florida State University wind data from 1961 through 1992,we find that the bifurcation latitude of the NEC changes with seasons.Furthermore,it is shown that the NEC bifurcation is at its southernmost latitude (12.7°N) in June and the northernmost latitude (14.4° N) in November.

  11. Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr

    Directory of Open Access Journals (Sweden)

    X. Crosta

    2012-03-01

    Full Text Available Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 15 000 calendar years Before Present (15 cal. ka BP and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms at the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP.

    Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, whose discharges were forced by precipitation changes over western Equatorial Africa and/or modification of the fluvio-deltaic systems forced by sea level changes. Precipitation in this region is controlled by the West African monsoon which is, in turn, partly dependent on the presence and intensity of the Atlantic Cold Tongue (ACT. Our results therefore suggest that the ACT was weakened, warmer trade winds were less vigorous, and cloud convection and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ∼10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely, the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and after 5.5 cal. ka BP into the present.

  12. Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr

    Directory of Open Access Journals (Sweden)

    X. Crosta

    2011-07-01

    Full Text Available Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 12 000 calendar years (12 cal. ka BP and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms to the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP.

    Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, which discharges were forced by precipitation over western Equatorial Africa. Precipitation in this region is controlled by the West African monsoon which is, in turn, dependent on the presence and intensity of the Atlantic Cold Tongue (ACT. The ACT was weakened and warmer, trade winds were less vigorous, could convection and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ~10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely, the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and since 5.5 cal. ka BP. Our results therefore give indication on the ocean and atmosphere dynamics over the last 40 000 yr.

  13. Ototoxicity of vancomycin in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    刘海瑛; 高文元; 刁明芳; 张琰敏; 韩红; 王建文

    2004-01-01

    Objective: To study the effect of vancomycin (V) with multiple intravenous injections on the inner ear of albino guinea pigs. Methods: Three groups of animals were injected with vancomycin hydrochloride (54, 108, 216 mg/kg tively as control groups. Auditory brainstem responses (ABR) and the duration of post-rotatory nystagmus (PRN) were measured before and after administration. Surface preparation and scanning electron microscopy (SEM) of the cochlea were performed for histological examination. Results: In V 54, 108 mg/kg group, similar to saline control, there was 0- 1.1 dB of threshold shift. In V 216 mg/kg group, average hearing loss was 1.0- 5.7 dB immediately after administration and 1.3 -3.8 dB after 14 d, which was significantly lower than those in GM control group. As the saline control, no significant difference was found in PRN in all V groups before and after treatment; while in the GM group, PRN decreased significantly after treatment. Morphological evaluation demonstrated that in all V and saline animals there was no obvious missing of outer and inner hair cells and SEM showed normal surface morphology. In the GM group, there was 10% - 30% of outer and inner hair cells lost in the basal turn. Conclusion: The ototoxicity of vancomycin is absent or minimal after multiple introvenous administration within this dose range.

  14. 9 CFR 3.36 - Primary enclosures used to transport live guinea pigs and hamsters.

    Science.gov (United States)

    2010-01-01

    ... live guinea pigs and hamsters. 3.36 Section 3.36 Animals and Animal Products ANIMAL AND PLANT HEALTH..., Care, Treatment, and Transportation of Guinea Pigs and Hamsters Transportation Standards § 3.36 Primary enclosures used to transport live guinea pigs and hamsters. No person subject to the Animal...

  15. Fourier Series Approximations to J2-Bounded Equatorial Orbits

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2014-01-01

    Full Text Available The current paper offers a comprehensive dynamical analysis and Fourier series approximations of J2-bounded equatorial orbits. The initial conditions of heterogeneous families of J2-perturbed equatorial orbits are determined first. Then the characteristics of two types of J2-bounded orbits, namely, pseudo-elliptic orbit and critical circular orbit, are studied. Due to the ambiguity of the closed-form solutions which comprise the elliptic integrals and Jacobian elliptic functions, showing little physical insight into the problem, a new scheme, termed Fourier series expansion, is adopted for approximation herein. Based on least-squares fitting to the coefficients, the solutions are expressed with arbitrary high-order Fourier series, since the radius and the flight time vary periodically as a function of the polar angle. As a consequence, the solutions can be written in terms of elementary functions such as cosines, rather than complex mathematical functions. Simulations enhance the proposed approximation method, showing bounded and negligible deviations. The approximation results show a promising prospect in preliminary orbits design, determination, and transfers for low-altitude spacecrafts.

  16. Transition from inspiral to plunge for eccentric equatorial Kerr orbits

    CERN Document Server

    O'Shaughnessy, R

    2003-01-01

    Ori and Thorne have discussed the duration and observability (with LISA) of the transition from circular, equatorial inspiral to plunge for stellar-mass objects into supermassive ($10^{5}-10^{8}M_{\\odot}$) Kerr black holes. We extend their computation to eccentric Kerr equatorial orbits. Even with orbital parameters near-exactly determined, we find that there is no universal length for the transition; rather, the length of the transition depends sensitively -- essentially randomly -- on initial conditions. Still, Ori and Thorne's zero-eccentricity results are essentially an upper bound on the length of eccentric transitions involving similar bodies (e.g., $a$ fixed). Hence the implications for observations are no better: if the massive body is $M=10^{6}M_{\\odot}$, the captured body has mass $m$, and the process occurs at distance $d$ from LISA, then $S/N \\lesssim (m/10 M_{\\odot})(1\\text{Gpc}/d)\\times O(1)$, with the precise constant depending on the black hole spin. For low-mass bodies ($m \\lesssim 7 M_\\odot$...

  17. Daytime plasma drifts in the equatorial lower ionosphere

    Science.gov (United States)

    Hui, Debrup; Fejer, Bela G.

    2015-11-01

    We have used extensive radar measurements from the Jicamarca Observatory during low solar flux periods to study the quiet time variability and altitudinal dependence of equatorial daytime vertical and zonal plasma drifts. The daytime vertical drifts are upward and have largest values during September-October. The day-to-day variability of these drifts does not change with height between 150 and 600 km, but the bimonthly variability is much larger in the F region than below about 200 km. These drifts vary linearly with height generally increasing in the morning and decreasing in the afternoon. The zonal drifts are westward during the day and have largest values during July-October. The 150 km region zonal drifts have much larger day-to-day, but much smaller bimonthly variability than the F region drifts. The daytime zonal drifts strongly increase with height up to about 300 km from March through October, and more weakly at higher altitudes. The December solstice zonal drifts have generally weaker altitudinal dependence, except perhaps below 200 km. Current theoretical and general circulation models do not reproduce the observed altitudinal variation of the daytime equatorial zonal drifts.

  18. LF equatorial emissions recorded by DEMETER/ICE experiment

    Science.gov (United States)

    Boudjada, Mohammed; Parrot, Michel; Schwingenschuh, Konrad; Eichelberger, Hans; Lammer, Helmut; Sawas, Sami; Denisenko, Valery; Besser, Bruno

    2016-07-01

    We report on electric field observations recorded on the Earth's night-side by DEMETER/ICE experiment. DEMETER is a low-altitude satellite with polar and circular orbits. Observations were recorded at invariant latitudes less than 65° and an altitude of about 650 km. The sun-synchronous night-side orbits correspond to up-going half-orbits with a local time equal to 22:30. We consider in our analysis the low frequency emissions observed at frequencies less than 500 kHz. We show the occurrence of multiple spaced frequency bands between 30 kHz and 500 kHz, and occasionally harmonic components appear in the upper frequency of the instrument (i.e. between 3 MHz - 3.5 MHz,). Those bands are recorded close to the equatorial plane, when the satellite latitudes are between -05° and +05°, and particular enhancements occur at two geographical longitudes, i.e. 130°E and 160°W. We assume that those low frequency radio waves may be associated to density irregularities in the equatorial region. Probably these irregularities are localized along ray paths between the emission source regions and the satellite. We discuss the source locations of such frequency bands, and we show that the observed spectral features may be linked to the plasmasphere dynamic.

  19. Recurring slope lineae in equatorial regions of Mars

    Science.gov (United States)

    McEwen, Alfred S.; Dundas, Colin M.; Mattson, Sarah S.; Toigo, Anthony D.; Ojha, Lujendra; Wray, James J.; Chojnacki, Matthew; Byrne, Shane; Murchie, Scott L.; Thomas, Nicolas

    2014-01-01

    The presence of liquid water is a requirement of habitability on a planet. Possible indicators of liquid surface water on Mars include intermittent flow-like features observed on sloping terrains. These recurring slope lineae are narrow, dark markings on steep slopes that appear and incrementally lengthen during warm seasons on low-albedo surfaces. The lineae fade in cooler seasons and recur over multiple Mars years. Recurring slope lineae were initially reported to appear and lengthen at mid-latitudes in the late southern spring and summer and are more common on equator-facing slopes where and when the peak surface temperatures are higher. Here we report extensive activity of recurring slope lineae in equatorial regions of Mars, particularly in the deep canyons of Valles Marineris, from analysis of data acquired by the Mars Reconnaissance Orbiter. We observe the lineae to be most active in seasons when the slopes often face the sun. Expected peak temperatures suggest that activity may not depend solely on temperature. Although the origin of the recurring slope lineae remains an open question, our observations are consistent with intermittent flow of briny water. Such an origin suggests surprisingly abundant liquid water in some near-surface equatorial regions of Mars.

  20. Quasi-periodic modulation of equatorial noise intensity

    Science.gov (United States)

    Nemec, Frantisek; Santolik, Ondrej; Hrbackova, Zuzana; Pickett, Jolene S.; Cornilleau-Wehrlin, Nicole

    2015-04-01

    Equatorial noise (EN) emissions are electromagnetic waves at frequencies between the proton cyclotron frequency and the lower hybrid frequency observed routinely in the equatorial region of the inner magnetosphere. They propagate in the extraordinary mode nearly perpendicular to the ambient magnetic field. Although their harmonic structure, which is characteristic of the proton cyclotron frequency in the source region has been known for a couple of decades, they were generally believed to be continuous in time. The analysis of more than 2000 EN events observed by the STAFF-SA and WBD instruments on board the Cluster spacecraft reveals that this is not always the case, with about 5% of events exhibiting a clear quasi-periodic (QP) modulation of the wave intensity. We perform a systematic analysis of these events, and we discuss possible mechanisms of the QP intensity modulation. It is shown that the events occur usually in the noon-to-dawn magnetic local time sector, and their occurrence seems to be related to the periods of increased geomagnetic activity. The modulation period of these events is on the order of minutes. Compressional ULF magnetic field pulsations with periods about double the modulation periods of EN were identified in about half of the events. These ULF pulsations might modulate the EN wave intensity, similarly as they modulate the intensity of formerly reported VLF whistler-mode QP events.

  1. SpIES: The Spitzer IRAC Equatorial Survey

    CERN Document Server

    Timlin, John D; Richards, Gordon T; Lacy, Mark; Ryan, Erin L; Stone, Robert B; Bauer, Franz E; Brandt, W N; Fan, Xiaohui; Glikman, Eilat; Haggard, Daryl; Jiang, Linhua; LaMassa, Stephanie M; Lin, Yen-Ting; Makler, Martin; McGehee, Peregrine; Myers, Adam D; Schneider, Donald P; Urry, C Megan; Wollack, Edward J; Zakamska, Nadia L

    2016-01-01

    We describe the first data release from the Spitzer-IRAC Equatorial Survey (SpIES); a large-area survey of 115 deg^2 in the Equatorial SDSS Stripe 82 field using Spitzer during its 'warm' mission phase. SpIES was designed to probe sufficient volume to perform measurements of quasar clustering and the luminosity function at z > 3 to test various models for "feedback" from active galactic nuclei (AGN). Additionally, the wide range of available multi-wavelength, multi-epoch ancillary data enables SpIES to identify both high-redshift (z > 5) quasars as well as obscured quasars missed by optical surveys. SpIES achieves 5{\\sigma} depths of 6.13 {\\mu}Jy (21.93 AB magnitude) and 5.75 {\\mu}Jy (22.0 AB magnitude) at 3.6 and 4.5 microns, respectively - depths significantly fainter than WISE. We show that the SpIES survey recovers a much larger fraction of spectroscopically-confirmed quasars (98%) in Stripe 82 than are recovered by WISE (55%). This depth is especially powerful at high-redshift (z > 3.5), where SpIES reco...

  2. Use of a Guinea pig-specific transcriptome array for evaluation of protective immunity against genital chlamydial infection following intranasal vaccination in Guinea pigs.

    Directory of Open Access Journals (Sweden)

    Shradha Wali

    Full Text Available Guinea pigs have been used as a second animal model to validate putative anti-chlamydial vaccine candidates tested in mice. However, the lack of guinea pig-specific reagents has limited the utility of this animal model in Chlamydia sp. vaccine studies. Using a novel guinea pig-specific transcriptome array, we determined correlates of protection in guinea pigs vaccinated with Chlamydia caviae (C. caviae via the intranasal route, previously reported by us and others to provide robust antigen specific immunity against subsequent intravaginal challenge. C. caviae vaccinated guinea pigs resolved genital infection by day 3 post challenge. In contrast, mock vaccinated animals continued to shed viable Chlamydia up to day 18 post challenge. Importantly, at day 80 post challenge, vaccinated guinea pigs experienced significantly reduced genital pathology - a sequelae of genital chlamydial infections, in comparison to mock vaccinated guinea pigs. Sera from vaccinated guinea pigs displayed antigen specific IgG responses and increased IgG1 and IgG2 titers capable of neutralizing GPIC in vitro. Th1-cellular/inflammatory immune genes and Th2-humoral associated genes were also found to be elevated in vaccinated guinea pigs at day 3 post-challenge and correlated with early clearance of the bacterium. Overall, this study provides the first evidence of guinea pig-specific genes involved in anti-chlamydial vaccination and illustrates the enhancement of the utility of this animal model in chlamydial pathogenesis.

  3. INVESTIGATION ON MODEL OF INFLAMMATORY PLEURAL EFFUSION IN GUINEA PIGS

    Institute of Scientific and Technical Information of China (English)

    冯源; 殷凯生; 王祥

    2002-01-01

    Objective To establish an animal model of inflammatory pleural effusion.Methods Forty guinea pigs were divided into two groups: experimental group with 7 subgroups and control group. In the experimental group the right chest cavity of each guinea pig was injected with 0.8~1.0 ml of 1% carrageenan, and guinea pigs of each subgroup were killed and observed respectively on day 1, 2, 3, 5, 7, 10 and day 14 after injection.Results Occurring on day 1(within 24 hours), pleural effusion reached the maximum on day 2~3 after injection, so did the neutrophil count in pleural effusion and inflammation of both pleura and lungs and then gradually decreased. The fibrosis and adhesion of pleura appeared on day 7 and were obvious on day 10. The encysted pleurisy was formed on day 14.Conclusion The carrageenan is an ideal pleural inflammatory inducer. This animal model is useful for studying pleural effusion.

  4. Logistics of Guinea worm disease eradication in South Sudan.

    Science.gov (United States)

    Jones, Alexander H; Becknell, Steven; Withers, P Craig; Ruiz-Tiben, Ernesto; Hopkins, Donald R; Stobbelaar, David; Makoy, Samuel Yibi

    2014-03-01

    From 2006 to 2012, the South Sudan Guinea Worm Eradication Program reduced new Guinea worm disease (dracunculiasis) cases by over 90%, despite substantial programmatic challenges. Program logistics have played a key role in program achievements to date. The program uses disease surveillance and program performance data and integrated technical-logistical staffing to maintain flexible and effective logistical support for active community-based surveillance and intervention delivery in thousands of remote communities. Lessons learned from logistical design and management can resonate across similar complex surveillance and public health intervention delivery programs, such as mass drug administration for the control of neglected tropical diseases and other disease eradication programs. Logistical challenges in various public health scenarios and the pivotal contribution of logistics to Guinea worm case reductions in South Sudan underscore the need for additional inquiry into the role of logistics in public health programming in low-income countries.

  5. Non-terminal blood sampling techniques in Guinea pigs

    DEFF Research Database (Denmark)

    Birck, Malene Muusfeldt; Tveden-Nyborg, Pernille; Lindblad, Maiken Marie;

    2014-01-01

    of guinea pigs are slightly different from other rodent models, hence modulation of sampling techniques to accommodate for species-specific differences, e.g., compared to mice and rats, are necessary to obtain sufficient and high quality samples. As both long and short term in vivo studies often require...... repeated blood sampling the choice of technique should be well considered in order to reduce stress and discomfort in the animals but also to ensure survival as well as compliance with requirements of sample size and accessibility. Venous blood samples can be obtained at a number of sites in guinea pigs e.......g., the saphenous and jugular veins, each technique containing both advantages and disadvantages(4,5). Here, we present four different blood sampling techniques for either conscious or anaesthetized guinea pigs. The procedures are all non-terminal procedures provided that sample volumes and number of samples do...

  6. Parallel plate capacitor analogy of equatorial plasma bubble and associated fringe fields with implications to equatorial valley region irregularities

    Science.gov (United States)

    Mukherjee, S.; Patra, A. K.

    2014-08-01

    VHF radar echoes from the valley region plasma irregularities, displaying ascending pattern, are often observed during the active phase of equatorial plasma bubble in the close vicinity of the geomagnetic equator and have been attributed to bubble-related fringe field effect. These irregularities however are not observed at a few degrees away from the equator. In this paper, we attempt to understand this contrasting observational result by comparing fringe field at the geomagnetic equator and low latitudes. We use parallel plate capacitor analogy of equatorial plasma bubble and choose a few capacitor configurations, consistent with commonly observed dimension and magnetic field-aligned property of plasma bubble, for computing fringe field. Results show that fringe field decreases significantly with decreasing altitude as expected. Further, fringe field decreases remarkably with latitude, which clearly indicates the role of magnetic field-aligned property of plasma bubble in reducing the magnitude of fringe field at low latitudes compared to that at the geomagnetic equator. The results are presented and discussed in the light of current understanding of plasma bubble-associated fringe field-induced plasma irregularities in the valley region.

  7. Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways.

    Directory of Open Access Journals (Sweden)

    Eric J Zaccone

    Full Text Available The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3 and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4 coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1, it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ "cough receptors" such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli.

  8. Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways.

    Science.gov (United States)

    Zaccone, Eric J; Lieu, TinaMarie; Muroi, Yukiko; Potenzieri, Carl; Undem, Blair E; Gao, Peisong; Han, Liang; Canning, Brendan J; Undem, Bradley J

    2016-01-01

    The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3) and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4) coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ "cough receptors" such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli. PMID:27213574

  9. Parainfluenza 3-Induced Cough Hypersensitivity in the Guinea Pig Airways

    Science.gov (United States)

    Lieu, TinaMarie; Muroi, Yukiko; Potenzieri, Carl; Undem, Blair E.; Gao, Peisong; Han, Liang; Canning, Brendan J.

    2016-01-01

    The effect of respiratory tract viral infection on evoked cough in guinea pigs was evaluated. Guinea pigs were inoculated intranasally with either parainfluenza type 3 (PIV3) and cough was quantified in conscious animals. The guinea pigs infected with PIV3 (day 4) coughed nearly three times more than those treated with the viral growth medium in response to capsaicin, citric acid, and bradykinin. Since capsaicin, citric acid, and bradykinin evoked coughing in guinea pigs can be inhibited by drugs that antagonize the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), it was reasoned that the virally-induced hypertussive state may involve alterations in TPRV1 activity. PIV3 infection caused a phenotypic switch in tracheal nodose Aδ “cough receptors” such that nearly 50% of neurons began to express, de novo, TRPV1 mRNA. There was also an increase TRPV1 expression in jugular C-fiber neurons as determined by qPCR. It has previously been reported that tracheal-specific nodose neurons express the BDNF receptor TrkB and jugular neurons express the NGF receptor TrkA. Jugular neurons also express the artemin receptor GFRα3. All these neurotrophic factors have been associated with increases in TRPV1 expression. In an ex vivo perfused guinea pig tracheal preparation, we demonstrated that within 8 h of PIV3 infusion there was no change in NGF mRNA expression, but there was nearly a 10-fold increase in BDNF mRNA in the tissue, and a small but significant elevation in the expression of artemin mRNA. In summary, PIV3 infection leads to elevations in TRPV1 expression in the two key cough evoking nerve subtypes in the guinea pig trachea, and this is associated with a hypertussive state with respect to various TRPV1 activating stimuli. PMID:27213574

  10. THE EFFECTS OF EL NINO AND LA NINA ON SEABIRD ASSEMBLAGES IN THE EQUATORIAL PACIFIC MONITORING

    Science.gov (United States)

    Spring and autumn cruises in Equatorial and Subtropical Surface waters were conducted 1984-1989 in the eastern equatorial Pacific. our genera predominated, both the relative contribution of each to species assemblages differed markedly depending on season and water mass. uring au...

  11. Odd gravitational harmonics of Jupiter: Effects of spherical versus nonspherical geometry and mathematical smoothing of the equatorially antisymmetric zonal winds across the equatorial plane

    Science.gov (United States)

    Kong, Dali; Zhang, Keke; Schubert, Gerald

    2016-10-01

    Unlike the even gravitational coefficients of Jupiter that are caused by both the rotational distortion and the equatorially symmetric zonal winds, the odd jovian gravitational coefficients are directly linked to the depth of the equatorially antisymmetric zonal winds. Accurate estimation of the wind-induced odd coefficients and comparison with measurements of those coefficients would be key to understanding the structure of the zonal winds in the deep interior of Jupiter. We consider two problems in connection with the jovian odd gravitational coefficients. In the first problem, we show, by solving the governing equations for the northern hemisphere of Jupiter subject to an appropriate condition at the equatorial plane, that the effect of non-spherical geometry makes an insignificant contribution to the lowermost-order odd gravitational coefficients. In the second problem, we investigate the effect of the equatorial smoothing used to avoid the discontinuity in the winds across the equatorial plane when the thermal wind equation is adopted to compute the odd gravitational coefficients. We reveal that, because of the dominant effect of the equatorial smoothing, the odd gravitational coefficients so obtained for deep zonal winds do not reflect physically realistic dynamics taking place in the deep interior of Jupiter.

  12. ESTUDIO DE VIABILIDAD DE UNA CLINICA PRIVADA EN GUINEA ECUATORIAL

    OpenAIRE

    TEN ROLDÁN, CARLOTA

    2012-01-01

    El presente documento contiene un estudio de viabilidad sobre un proyecto consistente en la construcción de una clínica privada en Guinea Ecuatorial, concretamente en la ciudad de Bata, la más poblada del país. Esta idea surge de un propósito real de llevar a cabo dicho proyecto por parte de un inversor nativo de Guinea Ecuatorial.La metodología empleada para llevar a cabo dicha tarea ha sido elaboración de un estudio del entorno, analizando las características demográficas y económicas del p...

  13. DOCA-salts induce heart failure in the guinea pig.

    Science.gov (United States)

    Tiritilli, A

    2001-10-01

    Heart failure (HF) is a common clinical problem confronting physicians and is often the final manifestation of many cardiovascular disorders. Despite recent advances in the pharmacological management of HF, it remains a highly lethal and disabling disorder. A number of animal models have been developed to study both the pathophysiology of HF and new therapeutic approaches to this complex syndrome. Only through an improved understanding of the basic biology of the early stages of the syndrome can HF be prevented or at least anticipated. With this in view, we have developed an easily realisable and inexpensive model in the guinea pig, which presents numerous structural, metabolic and biochemical similarities compared with the human heart. Thirty guinea pigs, aged 5 weeks and weighing 300 g were used. After anaesthesia, left nephrectomy was performed. After 1 week the guinea pigs were divided into: (a) control group (n=15), which received an injection of vehicle as well as tap water for 10 weeks; (b) DOCA-salts group (n=15), where the animals were treated with an IM injection of 10 mg DOCA 5 days a week for 10 weeks and with drinking water containing 9 g/l(-1) NaCl and 2 g/l(-1) KCl. Our results demonstrate that the administration of DOCA-salts to guinea pigs for 10 weeks caused a significant increase in blood pressure (BP+30%) associated with left ventricular hypertrophy (LVH), evaluated by LV weight (+37%), LV wall (+36%), by the ratio LV weight/Body weight (+23%) and by an increase in LV volume (+51%). Concerning HF, the latter was clinically evident through an increase in body weight, heart rate and dyspnoea. Indeed, guinea pigs presented pleural and/or pericardial effusion often associated with ascite. This model, which combines pressure and volume overload, results in a slow evolution towards HF. This allows a better understanding of the mechanisms in early LV remodelling which has the potential to develop into HF. Some recent studies have emphasised the value

  14. Spread F – an old equatorial aeronomy problem finally resolved?

    Directory of Open Access Journals (Sweden)

    R. F. Woodman

    2009-05-01

    Full Text Available One of the oldest scientific topics in Equatorial Aeronomy is related to Spread-F. It includes all our efforts to understand the physical mechanisms responsible for the existence of ionospheric F-region irregularities, the spread of the traces in a night-time equatorial ionogram – hence its name – and all other manifestations of the same. It was observed for the first time as an abnormal ionogram in Huancayo, about 70 years ago. But only recently are we coming to understand the physical mechanisms responsible for its occurrence and its capricious day to day variability. Several additional techniques have been used to reveal the spatial and temporal characteristics of the F-region irregularities responsible for the phenomenon. Among them we have, in chronological order, radio star scintillations, trans-equatorial radio propagation, satellite scintillations, radar backscatter, satellite and rocket in situ measurements, airglow, total electron content techniques using the propagation of satellite radio signals and, recently, radar imaging techniques. Theoretical efforts are as old as the observations. Nevertheless, 32 years after their discovery, Jicamarca radar observations showed that none of the theories that had been put forward could explain them completely. The observations showed that irregularities were detected at altitudes that were stable according to the mechanisms proposed. A breakthrough came a few years later, again from Jicamarca, by showing that some of the "stable" regions had become unstable by the non-linear propagation of the irregularities from the unstable to the stable region of the ionosphere in the form of bubbles of low density plasma. A problem remained, however; the primary instability mechanism proposed, an extended (generalized Rayleigh-Taylor instability, was too slow to explain the rapid development seen by the observations. Gravity waves in the neutral background have been proposed as a seeding mechanism to

  15. Seasonal-longitudinal variability of equatorial plasma bubbles

    Directory of Open Access Journals (Sweden)

    W. J. Burke

    2004-09-01

    Full Text Available We compare seasonal and longitudinal distributions of more than 8300 equatorial plasma bubbles (EPBs observed during a full solar cycle from 1989-2000 with predictions of two simple models. Both models are based on considerations of parameters that influence the linear growth rate, γRT, of the generalized Rayleigh-Taylor instability in the context of finite windows of opportunity available during the prereversal enhancement near sunset. These parameters are the strength of the equatorial magnetic field, Beq, and the angle, α, it makes with the dusk terminator line. The independence of α and Beq from the solar cycle phase justifies our comparisons.

    We have sorted data acquired during more than 75000 equatorial evening-sector passes of polar-orbiting Defense Meteorological Satellite Program (DMSP satellites into 24 longitude and 12 one-month bins, each containing ~250 samples. We show that: (1 in 44 out of 48 month-longitude bins EPB rates are largest within 30 days of when α=0°; (2 unpredicted phase shifts and asymmetries appear in occurrence rates at the two times per year when α≈0°; (3 While EPB occurrence rates vary inversely with Beq, the relationships are very different in regions where Beq is increasing and decreasing with longitude. Results (2 and (3 indicate that systematic forces not considered by the two models can become important. Damping by interhemispheric winds appears to be responsible for phase shifts in maximum rates of EPB occurrence from days when α=0°. Low EPB occurrence rates found at eastern Pacific longitudes suggest that radiation belt electrons in the drift loss cone reduce γRT by enhancing E-layer Pedersen conductances. Finally, we analyze an EPB event observed during a magnetic storm at a time and place where α≈-27°, to illustrate how electric-field penetration from

  16. Ebola Surveillance - Guinea, Liberia, and Sierra Leone.

    Science.gov (United States)

    McNamara, Lucy A; Schafer, Ilana J; Nolen, Leisha D; Gorina, Yelena; Redd, John T; Lo, Terrence; Ervin, Elizabeth; Henao, Olga; Dahl, Benjamin A; Morgan, Oliver; Hersey, Sara; Knust, Barbara

    2016-01-01

    Developing a surveillance system during a public health emergency is always challenging but is especially so in countries with limited public health infrastructure. Surveillance for Ebola virus disease (Ebola) in the West African countries heavily affected by Ebola (Guinea, Liberia, and Sierra Leone) faced numerous impediments, including insufficient numbers of trained staff, community reticence to report cases and contacts, limited information technology resources, limited telephone and Internet service, and overwhelming numbers of infected persons. Through the work of CDC and numerous partners, including the countries' ministries of health, the World Health Organization, and other government and nongovernment organizations, functional Ebola surveillance was established and maintained in these countries. CDC staff were heavily involved in implementing case-based surveillance systems, sustaining case surveillance and contact tracing, and interpreting surveillance data. In addition to helping the ministries of health and other partners understand and manage the epidemic, CDC's activities strengthened epidemiologic and data management capacity to improve routine surveillance in the countries affected, even after the Ebola epidemic ended, and enhanced local capacity to respond quickly to future public health emergencies. However, the many obstacles overcome during development of these Ebola surveillance systems highlight the need to have strong public health, surveillance, and information technology infrastructure in place before a public health emergency occurs. Intense, long-term focus on strengthening public health surveillance systems in developing countries, as described in the Global Health Security Agenda, is needed.The activities summarized in this report would not have been possible without collaboration with many U.S and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html). PMID:27389614

  17. Numerical Study on the Bifurcation of the North Equatorial Current

    Institute of Scientific and Technical Information of China (English)

    LIU Yulong; WANG Qi; SONG Jun; ZHU Xiande; GONG Xiaoqing; WU Fang

    2011-01-01

    A 1.5-layer reduced-gravity model forced by wind stress is used to study the bifurcations of the North Equatorial Current (NEC).The authors found that after removing the Ekman drift,the modelled circulations can serve well as a proxy of the SODA circulations on the σθ=25.0kgm-3 potential density surface based on available long-term reanalysis wind stress data.The modelled results show that the location of the western boundary bifurcation of the NEC depends on both zonal averaged and local zero wind stress curl latitude.The effects of the anomalous wind stress curl added in different areas are also investigated and it is found that they can change the strength of the Mindanao Eddy (ME),and then influence the interior pathway.

  18. Solar Wind Associated with Near Equatorial Coronal Hole

    Indian Academy of Sciences (India)

    M. Hegde; K. M. Hiremath; Vijayakumar H. Doddamani; Shashanka R. Gurumath

    2015-09-01

    Present study probes temporal changes in the area and radiative flux of near equatorial coronal hole associated with solar wind parameters such as wind speed, density, magnetic field and temperature. Using high temporal resolution data from SDO/AIA for the two wave-lengths 193 Å and 211 Å, area and radiative flux of coronal holes are extracted and are examined for the association with high speed solar wind parameters. We find a strong association between different parameters of coronal hole and solar wind. For both the wavelength bands, we also compute coronal hole radiative energy near the earth and it is found to be of similar order as that of solar wind energy. However, for the wavelength 193 Å, owing to almost similar magnitudes of energy emitted by coronal hole and energy due to solar wind, it is conjectured that solar wind might have originated around the same height where 193 Å line is formed in the corona.

  19. Observations of discrete harmonics emerging from equatorial noise

    Science.gov (United States)

    Balikhin, Michael A.; Shprits, Yuri Y.; Walker, Simon N.; Chen, Lunjin; Cornilleau-Wehrlin, Nicole; Dandouras, Iannis; Santolik, Ondrej; Carr, Christopher; Yearby, Keith H.; Weiss, Benjamin

    2015-07-01

    A number of modes of oscillations of particles and fields can exist in space plasmas. Since the early 1970s, space missions have observed noise-like plasma waves near the geomagnetic equator known as `equatorial noise'. Several theories were suggested, but clear observational evidence supported by realistic modelling has not been provided. Here we report on observations by the Cluster mission that clearly show the highly structured and periodic pattern of these waves. Very narrow-banded emissions at frequencies corresponding to exact multiples of the proton gyrofrequency (frequency of gyration around the field line) from the 17th up to the 30th harmonic are observed, indicating that these waves are generated by the proton distributions. Simultaneously with these coherent periodic structures in waves, the Cluster spacecraft observes `ring' distributions of protons in velocity space that provide the free energy for the waves. Calculated wave growth based on ion distributions shows a very similar pattern to the observations.

  20. Pelagic microplastics around an archipelago of the Equatorial Atlantic.

    Science.gov (United States)

    Ivar do Sul, Juliana A; Costa, Monica F; Barletta, Mário; Cysneiros, Francisco José A

    2013-10-15

    Plastic marine debris is presently widely recognised as an important environmental pollutant. Such debris is reported in every habitat of the oceans, from urban tourist beaches to remote islands and from the ocean surface to submarine canyons, and is found buried and deposited on sandy and cobble beaches. Plastic marine debris varies from micrometres to several metres in length and is potentially ingested by animals of every level of the marine food web. Here, we show that synthetic polymers are present in subsurface plankton samples around Saint Peter and Saint Paul Archipelago in the Equatorial Atlantic Ocean. To explain the distribution of microplastics around the Archipelago, we proposed a generalised linear model (GLM) that suggests the existence of an outward gradient of mean plastic-particle densities. Plastic items can be autochthonous or transported over large oceanic distances. One probable source is the small but persistent fishing fleet using the area.

  1. Solar cycle signatures in the NCEP equatorial annual oscillation

    Directory of Open Access Journals (Sweden)

    H. G. Mayr

    2009-08-01

    Full Text Available Our analysis of temperature and zonal wind data (1958 to 2006 from the National Center for Atmospheric Research (NCAR reanalysis (Re-1, supplied by the National Centers for Environmental Prediction (NCEP, shows that the hemispherically symmetric 12-month equatorial annual oscillation (EAO contains spectral signatures with periods around 11 years. Moving windows of 44 years show that, below 20 km, the 11-year modulation of the EAO is phase locked to the solar cycle (SC. The spectral features from the 48-year data record reveal modulation signatures of 9.6 and 12 years, which produce EAO variations that mimic in limited altitude regimes the varying maxima and minima of the 10.7 cm flux solar index. Above 20 km, the spectra also contain modulation signatures with periods around 11 years, but the filtered variations are too irregular to suggest that systematic SC forcing is the principal agent.

  2. Charging El Niño with off-equatorial westerly wind events

    Science.gov (United States)

    McGregor, Shayne; Timmermann, Axel; Jin, Fei-Fei; Kessler, William S.

    2016-08-01

    The buildup of the warm water in the equatorial Pacific prior to an El Niño event is considered a necessary precondition for event development, while the event initiation is thought to be triggered by bursts of westerly wind. However, in contrast to the view that warm water slowly builds up years before an El Niño event, the volume of warm water in the equatorial Pacific doubled in the first few months of 2014 reaching values that were consistent with the warm water buildup prior to the extreme 1997/1998 El Niño. It is notable that this dramatic warm water buildup coincided with a series of westerly wind bursts in the western tropical Pacific. This study uses linear wave theory to determine the effect of equatorial and off-equatorial westerly wind events on the Warm Water Volume (WWV) of the Pacific. It is found that westerly wind events have a significant impact on equatorial WWV with all events initially acting to increase WWV, which highlights why WWEs are so effective at exciting ENSO. In fact, our results suggest that the single westerly wind burst, which peaked in the first few days of March in 2014, was largely responsible for the coincident dramatic observed increase in WWV. How long the equatorial region remains charged, however, depends on the latitude of the westerly wind event. For instance, a single equatorially symmetric westerly wind event ultimately acts to discharge WWV via the reflection of upwelling Rossby waves, which makes it difficult to more gradually build WWV given multiple WWEs. In contrast, when the wind events occur off the equator, the subsequent discharge is significantly damped and in some cases the equatorial region can hold the heat charge for the duration of the simulations (~6 months). As such, off-equatorial WWEs can not only charge equatorial region WWV in the short term, but are also a mechanism to more gradually build equatorial region WWV in the longer term. Given that these off-equatorial WWEs have a relatively small

  3. Remuneration disparities in Oceania: Papua New Guinea and Solomon Islands.

    Science.gov (United States)

    Marai, Leo; Kewibu, Vincent; Kinkin, Elly; Peter Peniop, John; Salini, Christian; Kofana, Genesis

    2010-10-01

    This paper explores the impact of remuneration differences on workers in the Solomon Islands and Papua New Guinea. In these countries remunerative differences are linked to government policy (in Papua New Guinea) and job contracts (in the Solomon Islands), and have impacted on industrial relations in both settings (strike action). A total of N = 350 professionals (n = 60 expatriates) from 54 organizations in aid, government, higher education and industry (mean response rate = 36%) responded to an organizational survey form. Remuneration ratios between international and local respondents based on the World Bank's index of purchasing power parity approached 9:1. In both sites staff compared pay and benefits (remuneration) packages: Internationally remunerated staff rated their ability higher than their local counterparts did; locally remunerated groups reported more injustice in remuneration, were more demotivated by the gaps, and were more likely to be thinking about leaving the organization. In-country workshops of N = 40 largely local stakeholders from aid and community organizations plus government ministries considered the survey's findings and recommended: in Solomon Islands, (a) introducing a policy of localization, (b) establishing a remuneration commission (already existent in Papua New Guinea), and (c) reducing the remunerative gap; in Papua New Guinea, (d) reversing the post-Independence "dual pay system" (currently official policy), (e) instituting pay-for-performance, and (f) ensuring the existent localization policy is applied to recruitment, selection, and staff career planning and management.

  4. The endemic species of Podocarpus in New Guinea

    NARCIS (Netherlands)

    Laubenfels, de David J.

    1980-01-01

    Among the more than a dozen species of Podocarpus sensu stricto known to occur on the island of New Guinea inch New Britain, five are not known elsewhere. Unlike most of the non-endemic species, these five are widely distributed on the island in their appropriate ecological zones. Only one of the fi

  5. Remuneration disparities in Oceania: Papua New Guinea and Solomon Islands.

    Science.gov (United States)

    Marai, Leo; Kewibu, Vincent; Kinkin, Elly; Peter Peniop, John; Salini, Christian; Kofana, Genesis

    2010-10-01

    This paper explores the impact of remuneration differences on workers in the Solomon Islands and Papua New Guinea. In these countries remunerative differences are linked to government policy (in Papua New Guinea) and job contracts (in the Solomon Islands), and have impacted on industrial relations in both settings (strike action). A total of N = 350 professionals (n = 60 expatriates) from 54 organizations in aid, government, higher education and industry (mean response rate = 36%) responded to an organizational survey form. Remuneration ratios between international and local respondents based on the World Bank's index of purchasing power parity approached 9:1. In both sites staff compared pay and benefits (remuneration) packages: Internationally remunerated staff rated their ability higher than their local counterparts did; locally remunerated groups reported more injustice in remuneration, were more demotivated by the gaps, and were more likely to be thinking about leaving the organization. In-country workshops of N = 40 largely local stakeholders from aid and community organizations plus government ministries considered the survey's findings and recommended: in Solomon Islands, (a) introducing a policy of localization, (b) establishing a remuneration commission (already existent in Papua New Guinea), and (c) reducing the remunerative gap; in Papua New Guinea, (d) reversing the post-Independence "dual pay system" (currently official policy), (e) instituting pay-for-performance, and (f) ensuring the existent localization policy is applied to recruitment, selection, and staff career planning and management. PMID:22044056

  6. Good Order at Sea in the Gulf of Guinea

    DEFF Research Database (Denmark)

    Jacobsen, Katja Lindskov; Nordby, Johannes

    2015-01-01

    and Central African states decided to establish six maritime zones along their coastline in order to improve the maritime security in the Gulf of Guinea. A process heavily supported by UN’s International Maritime Organisation (IMO). Finally, the chapter suggests that maritime security issues in the Gulf...

  7. The Begoias of New Guinea – an overview

    NARCIS (Netherlands)

    Sands, M.J.S.

    2009-01-01

    A brief introduction to the family Begoniaceae and genus Begonia is followed by an outline of the key morphological characters of begonias and a review of the sections (Diploclinium, Petermannia and Symbegonia) and species of the genus occurring in New Guinea. The essential characteristics of these

  8. Feeding ecology of wintering terns in Guinea-Bissau

    NARCIS (Netherlands)

    Brenninkmeijer, A; Stienen, EWM; Klaassen, M; Kersten, M

    2002-01-01

    We studied the feeding ecology of Little Terns Sterna albifrons , Sandwich Terns S. sandvicensis and Royal Terns S. maxima in the Archipelago dos Bijagos (11degrees40'N, 15degrees45'W) in Guinea-Bissau (West Africa) during the winter of 1992/1993. More than 95% of all prey taken by these terns were

  9. Feeding ecology of wintering terns in Guinea-Bissau

    NARCIS (Netherlands)

    Brenninkmeijer, A.; Stienen, E.W.M.; Klaassen, M.R.J.; Kersten, M.

    2002-01-01

    We studied the feeding ecology of Little Terns Sterna albifrons, Sandwich Terns S. sandvicensis and Royal Terns S. maxima in the Archipélago dos Bijagós (11°40'N, 15°45'W) in Guinea-Bissau (West Africa) during the winter of 1992/1993. More than 95% of all prey taken by these terns were roundfish, ra

  10. Effect of experimental hypothyroidism on hearing in adult guinea pigs.

    OpenAIRE

    Stearns, M; Goodwin, P

    1983-01-01

    A group of guinea pigs was rendered hypothyroid using propylthiouracil solution in their drinking water. The animals were hypothyroid for at least 120 days. During this time no change was noted in their hearing thresholds for high-frequency clicks. The audiometric evaluation was performed using brainstem evoked response audiometry.

  11. Some liver function indicators in guinea pigs injected with cyanide

    Directory of Open Access Journals (Sweden)

    Idonije O. Blessing

    2013-08-01

    Full Text Available To determine the lethal effect of cyanide poisoning on the liver cells using ALP, AST, ALT and Bilirubin (Total and Conjugated as test indicators, eighteen (18 male guinea pigs, age matched were used for this study. This included 12 guinea pigs which served as test groups and injected with different concentrations of potassium cyanide saline solution while 6 guinea pigs without cyanide injection served as control group. Blood samples were collected from the guinea pigs three hours after the injections of the cyanide saline solution. The blood samples were analysed for liver enzymes and bilirubin using standard methods. The result of the plasma AST and ALT at the different concentrations showed decreased levels which were significant when compared with the controls. The plasma levels of Total and Conjugated bilirubin were also significantly decreased when compared with controls. However, the levels of the ALP in both test and control groups showed no significant difference. This study therefore highlighted the need to determine the levels of these liver function indicators in cases of cyanide poisoning to ensure efficient management of patients who are exposed to the cyanide.

  12. Survey of endoparasites in pet guinea pigs in Italy.

    Science.gov (United States)

    d'Ovidio, Dario; Noviello, Emilio; Ianniello, Davide; Cringoli, Giuseppe; Rinaldi, Laura

    2015-03-01

    Little information is available on the occurrence of endoparasites in pet guinea pigs (Cavia porcellus). The purpose of this study was to evaluate the prevalence of intestinal parasites in cavies kept as pets in southern Italy. Fresh fecal samples were randomly collected from 60 guinea pigs housed in pet shops or privately owned. All fecal samples were processed using the FLOTAC pellet technique to identify and count helminthic eggs/larvae and protozoan cysts/oocysts. In addition, the specimens were analyzed also by the Remel Xpect® Giardia/Cryptosporidium immunoassay. Intestinal parasites were detected in 19 out of 60 guinea pigs (31.7 %). Paraspidodera uncinata eggs were found in 13.3 % (8/60) of the rodents examined, Nippostrongylus-like eggs in 10 % (6/60), and finally Eimeria caviae oocysts were found in 10 % (6/60) of the animals. In one case, both E. caviae oocysts and P. uncinata eggs were found. None of the samples was positive for Cryptosporidium or Giardia. To the authors' knowledge, this is the first survey of endoparasites in pet guinea pigs in Italy.

  13. The species of Stegonotus (Serpentes, Colubridae) in Papua New Guinea

    NARCIS (Netherlands)

    Mcdowell, S.B.

    1972-01-01

    INTRODUCTION Currently, New Guinea Stegonotus with 17 scales at midbody and divided subcaudals are identified as S. modestus. But this will not account for the disparity in dentition within "S. modestus", nor the colour differences even at one locality, nor that in East and West Sepik Districts ther

  14. Guinea-Bissau : Land Tenure Issues and Policy Study

    OpenAIRE

    World Bank

    2006-01-01

    The present study reports on the Government of the Republic of Guinea-Bissau's efforts to develop a comprehensive strategy for enhancing land rights security and achieving social and economic development objectives. This report is divided into two main parts. The first part summarizes the current state of development of the government s land policy, as well as the legal and traditional fra...

  15. The genus Freycinetia (Pandanaceae) in New Guinea (Part 4)

    OpenAIRE

    Huynh, Kim-Lang

    2002-01-01

    Seventeen new species of Freycinetia Gaudich. are described from groups of islands of New Guinea: Freycinetia admiraltiensis, F. amoena, F. formosula, F. granulata, F. lanceolata, F. nakanaiensis, F. novobritannica (Bismarck Archipelago), F. relegata, F. rossellana (Louisiade Archipelago), F. angusta, F. awaiarensis, F. boluboluensis, F. fergussonensis, F. goodenoughensis, F. lenifolia, F. normanbyensis (D’Entrecasteaux Islands), and F. woodlarkensis (Woodlark Island). Specific characters fro...

  16. The alpine flora of Mount Wilhelm (New Guinea)

    NARCIS (Netherlands)

    Hoogland, R.D.

    1958-01-01

    The flora of the higher mountains of New Guinea has been the object of several extensive collecting trips in the past forty years. Until quite recently, however, a serious gap in our knowledge was the very scanty information available from the area between Mount Wilhelmina in the West and Mount Sara

  17. 9 CFR 113.38 - Guinea pig safety test.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Guinea pig safety test. 113.38 Section 113.38 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD...

  18. The vertical birthing position of the Trobrianders, Papua New Guinea.

    Science.gov (United States)

    Pöschl, U

    1987-05-01

    During an ethnomedical field study the author succeeded in participating and photographing 4 traditional birthgivings among the Trobrianders/Papua New Guinea. Their various vertical postures are described with special reference to specific Trobriand practices and discussed by literature review. The results suggest that vertical birthing positions are advantageous to horizontal ones and should be reconsidered by modern Western obstetrics.

  19. Sundhedsmaessige konsekvenser af en vaebnet konflikt i Guinea-Bissau

    DEFF Research Database (Denmark)

    Nielsen, Jens; Sodemann, Morten; Jakobsen, Marianne;

    2010-01-01

    The present paper reviews studies carried out by the Bandim Health Project during the armed conflict in Guinea-Bissau, 1998-1999. Common health interventions like vaccination and breastfeeding, as well as focused interventions such as nutrition interventions aimed at malnourished children...

  20. Nutrient deficiencies of agricultural crops in Papua New Guinea

    NARCIS (Netherlands)

    Hartemink, A.E.; Bourke, R.M.

    2000-01-01

    In Papua New Guinea the population is growing faster than the area under cultivation. As a result, land use is being intensified and soil nutrient depletion may occur, resulting in nutrient deficiencies of agricultural crops. This paper reviews nutrient deficiencies in the agricultural crops of Papu

  1. Day-to-day variability of Equatorial Ionization Anomaly over the Indian and Brazilian sectors - the role of Equatorial Electrojet

    Science.gov (United States)

    Kavutarapu, Venkatesh; Gende, Mauricio; Fagundes, Paulo Roberto; De Jesus, Rodolfo; Denardini, Clezio Marcos; De Abreu, Alessandro

    2016-07-01

    The equatorial electrojet (EEJ) is a narrow band of current flowing eastward at the ionospheric E-region altitudes along the dayside dip equator. Mutually perpendicular electric and magnetic fields over the equator results in the formation of Equatorial Ionization Anomaly (EIA) which in turn generates large electron density variabilities. Simultaneous study on the characteristics of EEJ and EIA is necessary to understand the role of EEJ on the EIA variabilities. Present study reports simultaneous variations of EEJ and GPS-TEC over Indian and Brazilian sectors to understand the role of EEJ on the day-to-day characteristics of the EIA. Magnetometer measurements during the low solar activity year 2004 are used to derive the EEJ values over the two different sectors. The characteristics of EIA are studied using two different chains of GPS receivers along the common meridian of 770E (India) and 450W (Brazil). The diurnal, seasonal and day-to-day variations of EEJ and TEC are described simultaneously. Variations of EIA during different seasons are presented along with the variations of the EEJ in the two hemispheres. The role of EEJ variations on the characteristic features of the EIA such as the strength and temporal extent of the EIA crest etc., have also been reported. Further, the time delay between the occurrences of the day maximum EEJ and the well-developed EIA are studied and corresponding results are presented in this paper. Further, the results from a study on the noon time bite-outs at the anomaly crest locations with their absence over the equator in the Indian and Brazilian sector are also discussed in this paper.

  2. Equatorial Energy Accumulation and Emanation Regions: Impacts of a Zonally Varying Basic State.

    Science.gov (United States)

    Webster, Peter J.; Chang, Hai-Ru

    1988-03-01

    Previous studies have suggested that the regions of mean anomalous perturbation kinetic energy which exist in the vicinity of the equatorial upper-tropospheric westerlies are the result of the propagation of extratropical synoptic and low frequency waves through the equatorial `westerly duet' where a subsequent wave energy convergence occurs. The proposition that these perturbed equatorial regions may arise from remote equatorial energy sources is investigated. It is shown that three criteria must be met. The first two, the existence of wave energy sources along the equator and a mechanism to transport that energy longitudinally, are accounted for relatively easily with existing theory of divergent, trapped equatorial modes. The third criterion, the requirement of a mechanism for an accumulation of transient energy in the equatorial stretch flow (i.e., nonzero x), is not immediately obvious and requires exploration to develop new concepts.Using simple WKBJ arguments it is shown that within a realistic parameter range, a combination of longitudinal stretch in the basic state along the equator and the characteristics of the equatorial trapped waves satisfy the third criterion. The equatorial waves must possess a divergent structure which insists on equatorial trapping. It is shown that purely barotropic modes, which cannot be equatorially trapped, do not represent the real atmospheric structure at low latitudes. Regions of negative longitudinal stretch along the equator (i.e., westerlies decreasing, or easterlies increasing, towards the cast) are shown to be wave energy accumulation regions. Regions with positive stretch, on the other hand, are wave energy depletion regions. A free-surface barotropic model with fully nonlinear basic states, containing both stretch and shear, confirm the results of the simpler model, i.e., regardless of the position of the energy source within the tropical atmosphere the wave energy accumulates in the same region; namely, on the

  3. A multi-model approach to the Atlantic Equatorial mode: impact on the West African monsoon

    Energy Technology Data Exchange (ETDEWEB)

    Losada, T.; Rodriguez-Fonseca, B. [Universidad Complutense de Madrid, Madrid (Spain); Janicot, S.; Gervois, S. [LOCEAN/IPSL, CNRS, Universite Pierre et Marie Curie, Paris (France); Chauvin, F. [GAME/CNRM, Meteo-France/CNRS, Toulouse (France); Ruti, P. [Progetto Speciale Clima Globale, Ente Nazionale per le NuoveTecnologie, Rome (Italy)

    2010-07-15

    This paper is focused on the West African anomalous precipitation response to an Atlantic Equatorial mode whose origin, development and damping resembles the observed one during the last decades of the XXth century. In the framework of the AMMA-EU project, this paper analyses the atmospheric response to the Equatorial mode using a multimodel approach with an ensemble of integrations from 4 AGCMs under a time varying Equatorial SST mode. The Guinean Gulf precipitation, which together with the Sahelian mode accounts for most of the summer West African rainfall variability, is highly coupled to this Equatorial Atlantic SST mode or Atlantic Nino. In a previous study, done with the same models under 1958-1997 observed prescribed SSTs, most of the models identify the Equatorial Atlantic SST mode as the one most related to the Guinean Gulf precipitation. The models response to the positive phase of equatorial Atlantic mode (warm SSTs) depicts a direct impact in the equatorial Atlantic, leading to a decrease of the local surface temperature gradient, weakening the West African Monsoon flow and the surface convergence over the Sahel. (orig.)

  4. Ocean dynamics, not dust, have controlled equatorial Pacific productivity over the past 500,000 years.

    Science.gov (United States)

    Winckler, Gisela; Anderson, Robert F; Jaccard, Samuel L; Marcantonio, Franco

    2016-05-31

    Biological productivity in the equatorial Pacific is relatively high compared with other low-latitude regimes, especially east of the dateline, where divergence driven by the trade winds brings nutrient-rich waters of the Equatorial Undercurrent to the surface. The equatorial Pacific is one of the three principal high-nutrient low-chlorophyll ocean regimes where biological utilization of nitrate and phosphate is limited, in part, by the availability of iron. Throughout most of the equatorial Pacific, upwelling of water from the Equatorial Undercurrent supplies far more dissolved iron than is delivered by dust, by as much as two orders of magnitude. Nevertheless, recent studies have inferred that the greater supply of dust during ice ages stimulated greater utilization of nutrients within the region of upwelling on the equator, thereby contributing to the sequestration of carbon in the ocean interior. Here we present proxy records for dust and for biological productivity over the past 500 ky at three sites spanning the breadth of the equatorial Pacific Ocean to test the dust fertilization hypothesis. Dust supply peaked under glacial conditions, consistent with previous studies, whereas proxies of export production exhibit maxima during ice age terminations. Temporal decoupling between dust supply and biological productivity indicates that other factors, likely involving ocean dynamics, played a greater role than dust in regulating equatorial Pacific productivity. PMID:27185933

  5. Ocean dynamics, not dust, have controlled equatorial Pacific productivity over the past 500,000 years

    Science.gov (United States)

    Winckler, Gisela; Anderson, Robert F.; Jaccard, Samuel L.; Marcantonio, Franco

    2016-05-01

    Biological productivity in the equatorial Pacific is relatively high compared with other low-latitude regimes, especially east of the dateline, where divergence driven by the trade winds brings nutrient-rich waters of the Equatorial Undercurrent to the surface. The equatorial Pacific is one of the three principal high-nutrient low-chlorophyll ocean regimes where biological utilization of nitrate and phosphate is limited, in part, by the availability of iron. Throughout most of the equatorial Pacific, upwelling of water from the Equatorial Undercurrent supplies far more dissolved iron than is delivered by dust, by as much as two orders of magnitude. Nevertheless, recent studies have inferred that the greater supply of dust during ice ages stimulated greater utilization of nutrients within the region of upwelling on the equator, thereby contributing to the sequestration of carbon in the ocean interior. Here we present proxy records for dust and for biological productivity over the past 500 ky at three sites spanning the breadth of the equatorial Pacific Ocean to test the dust fertilization hypothesis. Dust supply peaked under glacial conditions, consistent with previous studies, whereas proxies of export production exhibit maxima during ice age terminations. Temporal decoupling between dust supply and biological productivity indicates that other factors, likely involving ocean dynamics, played a greater role than dust in regulating equatorial Pacific productivity.

  6. Periodic Structure of Equatorial Envelope Rossby Wave Under Influence of Diabatic Heating

    Institute of Scientific and Technical Information of China (English)

    FUZun-Tao; CHENZhe; LIUShi-Da; LIUShi-Kuo

    2004-01-01

    A simple shallow-water model with influence of diabatic heating on a β-plane is applied to investigate the nonlinear equatorial Rossby waves in a shear flow. By the asymptotic method of multiple scales, the cubic nonlinear Schroedinger (NLS for short) equation with an external heating source is derived for large amplitude equatorial envelope Rossby wave in a shear flow. And then various periodic structures for these equatorial envelope Rossby waves are obtained with the help of Jacob/elliptic functions and elliptic equation. It is shown that phase-locked diabatic heating plays an important role in periodic structures of rational form.

  7. The Role of the Halted Baroclinic Mode at the Central Equatorial Pacific in El Ni(n)o Event

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The role of halted "baroclinic modes" in the central equatorial Pacific is analyzed. It is found that dominant anomaly signals corresponding to "baroclinic modes" occur in the upper layer of the equatorial Pacific, in a two-and-a-half layer oceanic model, in assimilated results of a simple OGCM and in the ADCP observation of TAO. A second "baroclinic mode" is halted in the central equatorial Pacific corresponding to a positive SST anomaly while the first "baroclinic mode" propagates eastwards in the eastern equatorial Pacific. The role of the halted second "baroclinic mode" in the central equatorial Pacific is explained by a staged ocean-atmosphere interaction mechanism in the formation of El Ni(n)o: the westerly bursts in boreal winter over the western equatorial Pacific generate the halted second "baroclinic mode" in the central equatorial Pacific, leading to the increase of heat content and temperature in the upper layer of the central Pacific which induces the shift of convection from over the western equatorial Pacific to the central equatorial Pacific; another wider, westerly anomaly burst is induced over the western region of convection above the central equatorial Pacific and the westerly anomaly burst generates the first "baroclinic mode"propagating to the eastern equatorial Pacific, resulting in a warm event in the eastern equatorial Pacific.The mechanism presented in this paper reveals that the central equatorial Pacific is a key region in detecting the possibility of ENSO and, by analyzing TAO observation data of ocean currents and temperature in the central equatorial Pacific, in predicting the coming of an El Ni(n)o several months ahead.

  8. Steepened structures in equatorial spread F. 1: New observations

    Science.gov (United States)

    Hysell, D. L.; Kelley, M. C.; Swartz, W. E.; Pfaff, R. F.; Swenson, C. M.

    1994-01-01

    Sounding rocket data from the 1990 Combined Release and Radiation Effects Satellite (CRRES)/EQUIS equatorial spread F campaign on Kwajalein Atoll are presented. Two Terrier Malamute sounding rockets were launched into active spread F conditions on July 30 and August 2, respectively, and achieved apogee slightly below 500 km, just above the F peak. Plasma frequency probes aboard both rockets showed that the unstable nighttime F region is characterized by propagating steepened structures. Power density spectra for the structures typically exhibit two regions that obey k(exp -n) scaling, where n is approximately equal to 2 at wavelengths greater than 80-100 m and approximately equal to 5 at shorter wavelengths. These spectral indices are quiet variable, and the long-wavelength spectral index in particular seems to decrease with increasing amplitude of density fluctuations. The rocket payloads also measured vector electric fields in the plane perpendicular to B over wavelengths ranging from over 60 km to less than 6 m. Both vector components of the perpendicular electric field are proportional to delta n/n at wavelengths longer than 300 m but assume a Boltzmann relationship (with square of the absolute value of delta E approximately equal to (k(exp2))(square of the absolute value of (delta n/n)) at smaller scales. The perturbed zonal electric field, delta E(sub x), dominates the vertical field, delta E(sub z), at long wavelenghts, but the situation is reversed at smaller scales.

  9. Steepened structures in equatorial spread F: 1. New observations

    Energy Technology Data Exchange (ETDEWEB)

    Hysell, D.L.; Kelley, M.C.; Swartz, W.E. [Cornell Univ., Ithaca, NY (United States)] [and others

    1994-05-01

    Sounding rocket data from the 1990 CRRES/EQUIS equatorial spread F campaign on Kwajalein Atoll are presented. Two Terrier Malamute sounding rockets were launched into active spread F conditions on July 30 and August 2, respectively, and achieved apogee slightly below 500 km, just above the F peak. Plasma frequency probes aboard both rockets showed that the unstable nighttime F region is characterized by propagating steepened structures. Power density spectra for the structures typically exhibit two regions that obey k{sup {minus}n} scaling, where n is approximately equal to 2 at wavelengths greater than 80-100 m and approximately equal to 5 at shorter wavelengths. These spectral indices are quite variable, and the long-wavelength spectral index in particular seems to decrease with increasing amplitude of density fluctuations. The rocket payloads also measured vector electric fields in the plane perpendicular to B over wavelengths ranging from over 60 km to less than 6 m. Both vector components of the perpendicular electric field are proportional to {delta}n/n at wavelengths longer than 300 m but assume a Boltzmann relationship (with {vert_bar}{delta}E{vert_bar}{sup 2} {approximately} k{sup 2}{vert_bar}{delta}n/n{vert_bar}{sup 2}) at smaller scales. The perturbed zonal electric field, {delta}E{sub x}, dominates the vertical field, {delta}E{sub z}, at long wavelengths, but the situation is reversed at smaller scales. 25 refs., 7 figs.

  10. Bifurcation of Pacific North Equatorial Current at the surface

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The grid altimetry data between 1993 and 2006 near the Philippines were analyzed by the method of Empirical Orthogonal Function (EOF) to study the variation of bifurcation of the North Equatorial Current at the surface of the Pacific. The relatively short-term signals with periods of about 6 months, 4 months, 3 months and 2 months are found besides seasonal and interannual variations mentioned in previous studies. Local wind stress curl plays an important role in controlling variation of bifurcation latitude except in the interannual timescale. The bifurcation latitude is about 13.3°N in annual mean state and it lies at the northernmost position (14.0°N) in January, at the southernmost position (12.5°N) in July. The amplitude of variation of bifurcation latitude in a year is 1.5°, which can mainly be explained as the contributions of the signals with periods of about 1 year (1.2°) and 0.5 year (0.3°).

  11. Equatorial segment of the mid-atlantic ridge

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The Equatorial Segment of the Mid-Atlantic Ridge is a part of this mid-oceanic ridge limited by a cluster of fracture zones - Cape Verde, Marathon, Mercury, Vema, Doldrums, Vernadsky and Sierra Leone - in the North, and a similar cluster of fracture zones - St Paul, Romanche and Chain - in the South. During recent decades, following the publication of the 5. edition of the General Bathymetric Chart of the Oceans (GEBCO), there has been a great deal of geological-geophysical research and mapping of the World Ocean. The results have led to the development of a number of theories concerning the essential heterogeneity of the structure of the ocean floor and, in particular, the heterogeneity of the structure and segmentation of mid-oceanic ridges. Research on the nature of such segmentation is of great importance for an understanding of the processes of development of such ridges and oceanic basins as a whole. Chapter 20 is dedicated to the study of the atlantic ocean mantle by using (Th.U)Th, (Th/U)pb and K/Ti systematics 380 refs.

  12. Periodicity in the occurrence of equatorial plasma bubbles

    Science.gov (United States)

    Choi, J.; Kim, Y.; Kil, H.; Kwak, Y.; Lee, W.

    2013-12-01

    The observations of equatorial plasma bubbles by low-inclination orbit satellites show periodic occurrence of bubbles along satellite orbits. The periodicity in the bubble occurrence provides a useful tool for identifying the role of gravity waves in the creation of bubbles. In this study, we investigate the variability of the periodicity in the bubble occurrence by analyzing the observations of Communication/Navigation Outage Forecasting System (C/NOFS) and the first Republic of China satellite (ROCSAT-1). Here the periodicity indicates spatial periodicity and is derived by applying a Fourier analysis to the electron densities projected onto the magnetic apex height. Our preliminary results show an occurrence of significant amplitudes of periodicity peaks on the spatial scale range of 50-1000 km. The periodicity on small scales may be associated with the bifurcation of bubbles or to the creation of multiple bubbles for one wave seeding. The periodicity on larger scales is considered to be related with the scale size of a seeding mechanism. We present statistics of the periodicity and the coincident satellite observations of periodic bubbles with ground observations.

  13. Equatorial plasma bubbles with enhanced ion and electron temperatures

    Science.gov (United States)

    Park, Jaeheung; Min, Kyoung Wook; Kim, Vitaly P.; Kil, Hyosub; Su, Shin-Yi; Chao, Chi Kuang; Lee, Jae-Jin

    2008-09-01

    While the ion and electron temperatures inside equatorial plasma bubbles (EPBs) are normally lower than those in an ambient plasma, bubbles with enhanced temperatures (BETs) are found occasionally in the topside ionosphere. Here we report the characteristics of BETs identified from observations of the first Republic of China Satellite (ROCSAT-1), the first Korea Multi-purpose Satellite (KOMPSAT-1), and the Defense Meteorological Satellite Program (DMSP) F15 during the solar maximum period between 2000 and 2001. The oxygen ion fraction inside the BETs, which was no lower than that of the ambient ionosphere, was similar to the case of ordinary low-temperature EPBs. These observations indicate that the BETs and low-temperature EPBs detected on the topside were produced by the upward drift of low-density plasma from lower altitudes. The feature that distinguishes BETs from normal EPBs is the occurrence of an unusually fast poleward field-aligned plasma flow relative to the ambient plasma. The BETs occurred preferentially around geomagnetic latitudes of 10° in the summer hemisphere, where the ambient ion and electron temperatures are lower than those in the conjugate winter hemisphere. The occurrence of BETs did not show any notable dependence on geomagnetic activities. The characteristics of the BETs suggest that the BETs were produced by adiabatic plasma heating associated with a fast poleward oxygen ion transport along magnetic flux tubes.

  14. Sensor-controlled heliostat with an equatorial mount

    Energy Technology Data Exchange (ETDEWEB)

    Aiuchi, Kosuke; Yoshida, Kazuo; Onozaki, Masaki; Katayama, Yukuo [The Institute of Applied Energy, Tokyo (Japan); Nakamura, Minoru; Nakamura, Katsushige [Mitaka Kohki Co. Ltd., Tokyo (Japan)

    2006-09-15

    A heliostat having a photo-sensor sun-tracking system was developed and evaluated. The sensor was composed of a set of two photo-cells placed side by side on the bottom of the small box. Sun-tracking can be achieved by rotating the heliostat equipped with the sensor, while maintaining the two photo-cells under illumination by the sun through a slit in the box. A preliminary tracking evaluation of the sensor was carried out with the aid of a mirror-telescope system, and the tracking error was estimated to be less than 0.6mrad in clear weather. The developed heliostat employed an equatorial mount system that permits the rotating speed of the right-ascension axis to be nearly constant for the diurnal motion of the sun. The use of two additional sensors, a cloud sensor and a primary sensor, permitted stable tracking with high accuracy even in a cloudy sky. Field tests of the heliostat revealed that an angular error within 2mrad was achieved in fine weather. In cloudy weather, the heliostat operated stably with the cloud sensor within an error of 10mrad. (author)

  15. Equatorial and Low-Latitudes Ionospheric Reaction to Solar Flares

    Science.gov (United States)

    Nicoli Candido, C. M.; Becker-Guedes, F.; Paula, E. R.; Takahashi, H.

    2015-12-01

    Solar X-ray and extreme ultraviolet (EUV) photons are responsible for ionizing the terrestrial atmosphere and create the ionosphere. During solar flares, a fast increase in the electron density at different altitude regions takes place due to the abrupt enhance of the X-ray and EUV fluxes reaching Earth. With these changes in the ionosphere, radio communication and navigation can be drastically affected. The magnitudes of these Space Weather events can be related to the X-ray peak brightness and duration, which drive the intensity of the ionosphere response when the associated electromagnetic wave hit the sunlit side of the Earth's atmosphere. Other aspects defining these changes in a particular region are the local time, the solar zenith angle, and the position of the flare in the solar disc for each event. In order to improve the understand of radio signal degradation and loss in the Brazilian sector due to solar abrupt electromagnetic emissions, total electron content (TEC) data obtained by a GPS network formed by tents of dual-frequency receivers spread all over Brazilian territory were analyzed. It was observed different ionospheric local changes during several X-ray events identified by GOES satellite regarding the 0.1-0.8 nm range, and some case studies were ponder for a more detailed analysis of these effects. Considering the results, we have made an estimation of the ionospheric disturbances range for a particular event with great chance to affect space based communications in the equatorial and low-latitude regions.

  16. Ion composition of the topside equatorial ionosphere during solar minimum

    Science.gov (United States)

    Gonzalez, S. A.; Fejer, B. G.; Heels, R. A.; Hanson, W. B.

    1992-01-01

    Observations from both the Bennett ion mass spectrometer and the retarding potential analyzer on board the Atmosphere Explorer E satellite were used to study the longitudinally averaged O(+), H(+), and He(+) concentrations from 150 to 1100 km in the equatorial ionosphere during the 1975-1976 solar minimum. The results suggest that the ion mass spectrometer measurements need to be increased by a factor of 2.15 to agree with the densities from the retarding potential analyzer and with ground-based measurements. The peak H(+) concentrations are about 2.5 x 10 exp 4/cu cm during the day and 10 exp 4/cu cm at night and vary little with season. The O(+)/H(+) transition altitude lies between 750 and 825 km during the day and between 550 and 600 km at night. He(+) is a minor species at all altitudes; its concentration is highly variable with a maximum value of about 10 exp 3/cu cm during equinox daytime.

  17. Equatorial wave activity during 2007 over Gadanki, a tropical station

    Indian Academy of Sciences (India)

    Salauddin Mohammad; Gopa Dutta; B Venkateswara Rao; P Vinay Kumar

    2015-06-01

    ECMWF Re-Analysis (ERA-interim) data of winds for the year 2007 between the pressure levels 1 and 1000 hPa (0–49 km) have been analyzed for equatorial wave activity over a tropical station Gadanki (13.5°N, 79.2°E). Available wind observations made by MST radar located at the same site have also been used to investigate the wave activity in the troposphere and lower stratosphere. Waves in the period bands 7–10, 12–15 and 20–30 d are observed. Temporal variability of the wave activity has been investigated by constructing wavelet spectra. The longer period waves show strong seasonal variability with maximum and minimum activities during winter and summer months respectively. Short period activity is more prominent during June–July–August in the tropospheric region. The waves are found to be generated in the troposphere by wind shear and convection. Propagation of the waves to higher altitudes is found to depend strongly on background zonal wind and phase of the quasi-biennial oscillation (QBO). The waves are inhibited to propagate through the negative wind shear zone. Meridional waves might be generated by non-linear wave CISK.

  18. Equatorial segment of the mid-atlantic ridge

    International Nuclear Information System (INIS)

    The Equatorial Segment of the Mid-Atlantic Ridge is a part of this mid-oceanic ridge limited by a cluster of fracture zones - Cape Verde, Marathon, Mercury, Vema, Doldrums, Vernadsky and Sierra Leone - in the North, and a similar cluster of fracture zones - St Paul, Romanche and Chain - in the South. During recent decades, following the publication of the 5. edition of the General Bathymetric Chart of the Oceans (GEBCO), there has been a great deal of geological-geophysical research and mapping of the World Ocean. The results have led to the development of a number of theories concerning the essential heterogeneity of the structure of the ocean floor and, in particular, the heterogeneity of the structure and segmentation of mid-oceanic ridges. Research on the nature of such segmentation is of great importance for an understanding of the processes of development of such ridges and oceanic basins as a whole. Chapter 20 is dedicated to the study of the atlantic ocean mantle by using (Th.U)Th, (Th/U)pb and K/Ti systematics

  19. Equatorial ionospheric disturbance observed through a transequatorial HF propagation experiment

    Directory of Open Access Journals (Sweden)

    T. Maruyama

    2006-07-01

    Full Text Available A transequatorial radio-wave propagation experiment at shortwave frequencies (HF-TEP was done between Shepparton, Australia, and Oarai, Japan, using the radio broadcasting signals of Radio Australia. The receiving facility at Oarai was capable of direction finding based on the MUSIC (Multiple Signal Classification algorithm. The results were plotted in azimuth-time diagrams (AT plots. During the daytime, the propagation path was close to the great circle connecting Shepparton and Oarai, thus forming a single line in the AT plots. After sunset, off-great-circle paths, or satellite traces in the AT plot, often appeared abruptly to the west and gradually returned to the great circle direction. However, there were very few signals across the great circle to the east. The off-great-circle propagation was very similar to that previously reported and was attributed to reflection by an ionospheric structure near the equator. From the rate of change in the direction, we estimated the drift velocity of the structure to range mostly from 100 to 300 m/s eastward. Multiple instances of off-great-circle propagation with a quasi-periodicity were often observed and their spatial distance in the east-west direction was within the range of large-scale traveling ionospheric disturbances (LS-TIDs. Off-great-circle propagation events were frequently observed in the equinox seasons. Because there were many morphological similarities, the events were attributed to the onset of equatorial plasma bubbles.

  20. Can Logging in Equatorial Africa Affect Adjacent Parks?

    Directory of Open Access Journals (Sweden)

    Jeremy W. Lichstein

    2005-06-01

    Full Text Available Tropical deforestation can cause fundamental regional-scale shifts in vegetation structure and diversity. This is particularly true in Africa. Although national parks are being established to protect areas from deforestation and to conserve biodiversity, these parks are not immune to disturbances outside their boundaries. We used regional-scale atmospheric simulation experiments to investigate how deforestation in timber concessions might affect precipitation inside adjacent, undisturbed national parks in the equatorial African countries of Gabon and the Republic of Congo. The experiments revealed a complex response. Some parks showed rainfall reduced as much as 15%, while others showed slight increases. Rainfall inside parks was particularly sensitive to upwind deforestation along the path of airborne moisture traveling inland from the ocean. A variety of shortcomings in the current modeling procedures limit the ability to extrapolate from experiments such as ours to provide spatially explicit, long-term forecasts of climate. We describe what advances in modeling are needed to produce regional-scale predictions that are robust enough to be useful to managers and policy makers.

  1. Electric field diagnostics of the dynamics of equatorial density depletions

    Science.gov (United States)

    Laakso, H.; Maynard, N. C.; Pfaff, R. F.; Aggson, T. L.; Coley, W. R.; Janhunen, P.; Herrero, F. A.

    1997-09-01

    During its life of 10 months, the San Marco D satellite crossed a large number of plasma density depletion channels in the nightside F-region equatorial ionosphere. In-situ measurements of vector electric fields from San Marco D reveal convection velocity variations inside such channels and thus can be used as diagnostics of the dynamics of these plasma depleted regions. Furthermore, in some cases, the temporal evolution of the channel can be inferred from the measurements. In this paper the electric field data are converted to plasma drift velocities in order to illustrate cases where the plasma flow is directed upward or downward in the channel, the channel itself is oriented vertically upward or tilted eastward/westward, or the channel is experiencing a bifurcation or pinching-off process. Although the E × B plasma drift velocities within the depleted channels are commonly a few hundred m s-1, on some occasions electric fields corresponding to speeds as large as 2-3 km s-1 have been observed. The implications for such highly supersonic convection are discussed, including the possible constriction of such high-speed depletion channels at higher altitudes.

  2. Equatorial ionospheric disturbance observed through a transequatorial HF propagation experiment

    Science.gov (United States)

    Maruyama, T.; Kawamura, M.

    2006-07-01

    A transequatorial radio-wave propagation experiment at shortwave frequencies (HF-TEP) was done between Shepparton, Australia, and Oarai, Japan, using the radio broadcasting signals of Radio Australia. The receiving facility at Oarai was capable of direction finding based on the MUSIC (Multiple Signal Classification) algorithm. The results were plotted in azimuth-time diagrams (AT plots). During the daytime, the propagation path was close to the great circle connecting Shepparton and Oarai, thus forming a single line in the AT plots. After sunset, off-great-circle paths, or satellite traces in the AT plot, often appeared abruptly to the west and gradually returned to the great circle direction. However, there were very few signals across the great circle to the east. The off-great-circle propagation was very similar to that previously reported and was attributed to reflection by an ionospheric structure near the equator. From the rate of change in the direction, we estimated the drift velocity of the structure to range mostly from 100 to 300 m/s eastward. Multiple instances of off-great-circle propagation with a quasi-periodicity were often observed and their spatial distance in the east-west direction was within the range of large-scale traveling ionospheric disturbances (LS-TIDs). Off-great-circle propagation events were frequently observed in the equinox seasons. Because there were many morphological similarities, the events were attributed to the onset of equatorial plasma bubbles.

  3. Surface currents in the equatorial Indian Ocean during spring and fall - An altimetry based analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Somayajulu, Y.K.

    This communication presents the results of a study aimed at investigating the nature and variability of surface currents in the equatorial Indian Ocean between 5 degrees N and 5 degrees S during spring and fall seasons. Geostrophic surface currents...

  4. Weight Percentage of Calcium Carbonate for 17 Equatorial Pacific Cores from Brown University

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weight percentages of calcium carbonate in this file were compiled by J. Farrell and W. L. Prell of Brown University for 17 equatorial Pacific Ocean sediment cores....

  5. Radar and satellite global equatorial F-region vertical drift model

    OpenAIRE

    L. Scherliess; Fejer, Bela G.

    1999-01-01

    We present the first global empirical model for the quiet time F region equatorial vertical drifts based on combined incoherent scatter radar observations at Jicamarca and Ion Drift Meter observations on board the Atmospheric Explorer E satellite. This analytical model, based on products of cubic-B splines and with nearly conservative electric fields, describes the diurnal and seasonal variations of the equatorial vertical drifts for a continuous range of all longitudes and solar flux values....

  6. Primary productivity and its variability in the equatorial South China Sea during the northeast monsoon

    OpenAIRE

    S. H. Ooi; Samah, A.A.; Braesicke, P.

    2013-01-01

    Near coastal areas of the equatorial South China Sea (SCS) are one of the world's regions with highest primary productivity (phytoplankton growth). Concentrations of phytoplankton in the SCS depend significantly on atmospheric forcings and the oceanic state, in particular during the northeast (winter) monsoon season from November to March. Aided by new ocean-observing satellite data, we present a climatological overview of recent surface atmospheric and oceanic features in the equatorial SCS ...

  7. The effect of J{sub 2} on equatorial and halo orbits around a magnetic planet

    Energy Technology Data Exchange (ETDEWEB)

    Inarrea, Manuel [Universidad de la Rioja, Area de Fisica, 26006 Logrono (Spain); Lanchares, Victor [Dpto. de Matematicas y Computacion, CIEMUR: Centro de Investigacion en Informatica, Estadistica y Matematicas, Universidad de la Rioja, 26004 Logrono (Spain)], E-mail: vlancha@unirioja.es; Palacian, Jesus F. [Universidad Publica de Navarra, Departamento de Ingenieria Matematica e Informatica, 31006 Pamplona (Spain); Pascual, Ana I. [Dpto. de Matematicas y Computacion, CIEMUR: Centro de Investigacion en Informatica, Estadistica y Matematicas, Universidad de la Rioja, 26004 Logrono (Spain); Pablo Salas, J. [Universidad de la Rioja, Area de Fisica, 26006 Logrono (Spain); Yanguas, Patricia [Universidad Publica de Navarra, Departamento de Ingenieria Matematica e Informatica, 31006 Pamplona (Spain)

    2009-10-15

    We calculate equatorial and halo orbits around a non-spherical (both oblate and prolate) magnetic planet. It is known that circular equatorial and halo orbits exist for a dust grain orbiting a spherical magnetic planet. However, the frequency of the orbit is constrained by the charge-mass ratio of the particle. If the non-sphericity of the planet is taken into account this constraint is modified or, in some cases, it disappears.

  8. HF Doppler radar observations of equatorial plasma drifts and spread-F

    Science.gov (United States)

    Jayachandran, B.; Namboothiri, S. P.; Balan, N.; Rao, P. B.; Sastri, J. H.

    Vertical plasma drift measurements have been made by an HF Doppler radar at the equatorial station of Trivandrum. For magnetically quiet conditions, Doppler observations are presented dealing with (1) the postsunset vertical plasma drifts and their seasonal dependence, (2) the prereversal enhancement in the vertical plasma drift and the occurrence of equatorial spread-F, and (3) the vector plasma drift measurements for a sample equinoctial day.

  9. Understanding the Longitudinal Variability of Equatorial Electrodynamics using integrated Ground- and Space-based Observations

    Science.gov (United States)

    Yizengaw, E.; Moldwin, M.; Zesta, E.

    2015-12-01

    The currently funded African Meridian B-Field Education and Research (AMBER) magnetometer array comprises more than thirteen magnetometers stationed globally in the vicinity of geomagnetic equator. One of the main objectives of AMBER network is to understand the longitudinal variability of equatorial electrodynamics as function of local time, magnetic activity, and season. While providing complete meridian observation in the region and filling the largest land-based gap in global magnetometer coverage, the AMBER array addresses two fundamental areas of space physics: first, the processes governing electrodynamics of the equatorial ionosphere as a function of latitude (or L-shell), local time, longitude, magnetic activity, and season, and second, ULF pulsation strength at low/mid-latitude regions and its connection with equatorial electrojet and density fluctuation. The global AMBER network can also be used to augment observations from space-based instruments, such us the triplet SWARM mission and the upcoming ICON missions. Thus, in coordination with space-based and other ground-based observations, the AMBER magnetometer network provides a great opportunity to understand the electrodynamics that governs equatorial ionosphere motions. In this paper we present the longitudinal variability of the equatorial electrodynamics using the combination of instruments onboard SWARM and C/NOFS satellites and ground-based AMBER network. Both ground- and pace-based observations show stronger dayside and evening sector equatorial electrodynamics in the American and Asian sectors compared to the African sector. On the other hand, the African sector is home to stronger and year-round ionospheric bubbles/irregularities compared to the American and Asian sectors. This raises the question if the evening sector equatorial electrodynamics (vertical drift), which is believed to be the main cause for the enhancement of Rayleigh-Taylor (RT) instability growth rate, is stronger in the

  10. The anaphylactic release of platelet-activating factor from perfused guinea-pig lungs.

    OpenAIRE

    Fitzgerald, M. F.; Moncada, S; Parente, L.

    1986-01-01

    The release of platelet-activating factor (Paf-acether) and of its inactive precursor/metabolite lyso-platelet activating factor (lyso-Paf) from control and sensitized guinea-pig isolated lungs challenged with antigen was investigated. Control guinea-pig lungs perfused either through the pulmonary circulation or through the airways and challenged with antigen did not release Paf-acether. Sensitized guinea-pig isolated lungs perfused through the pulmonary circulation and challenged with antige...

  11. On the relationship between the Meridional Mode and the equatorial SST anomalies

    Science.gov (United States)

    Martín-Rey, Marta; Lazar, Alban

    2016-04-01

    The tropical Atlantic climate is dominated by two modes of variability at inter-annual time scales, the Equatorial Mode (EM) and the Meridional Mode (MM). They are characterized by specific Sea Surface Temperature anomalies (SSTA) distributions, respectively with a maximum over the central-eastern equator during boreal summer, and with an inter-hemispheric gradient during boreal spring. Although their structures, air-sea interactions and impacts have been widely studied, the processes associated to their development, and their connections, still remain a challenge. In the present work, we present a classification of MM events, regarding to their connections with the successive equatorial summer SSTA, associated with an EM or neutral conditions. The MM-I events display SSTA in North Tropical Atlantic (NTA) followed by a same sign summer equatorial SSTA. The MM-II events are related to NTA SSTA and successive equatorial summer SSTA of opposite sign. For both types, the spring north-eastern trades anomalies could generate SSTA impacting on the equatorial SSTA. Nevertheless, it is evidenced that the anomalous wind pattern shown along the equatorial band and South Tropical Atlantic is crucial to give rise, or not, to an EM. In order to further analyse the air-sea interactions and oceanic processes at work in the two different MM types, sensitivity experiments with different wind forcings are performed with the NEMO OGCM.

  12. 赤道几内亚总统府规划与建筑设计%Planning and Architectural Design for the Presidential Palace of Equatorial Guinea

    Institute of Scientific and Technical Information of China (English)

    邱少成

    2008-01-01

    近年来,中非在各方面的交流日益加强,为中国建筑师到非洲进行建筑设计提供了越来越多的机会.文章通过时赤道几内亚总统府设计过程中的心得介绍,表达了在特定环境下设计者对建筑地域性、建筑内涵、功能、宗教、礼仪、材料、安防,尤其是建筑空间本质的关注.

  13. Mineral-Rich Countries and Dutch Disease : Understanding the Macroeconomic Implications of Windfalls and the Development Prospects, The Case of Equatorial Guinea

    OpenAIRE

    Toto Same, Achille

    2008-01-01

    Referring to the original context of Dutch Disease, the term refers to the fears of de-industrialization that gripped the Netherlands as a result of the appreciation of the Dutch currency that followed the discovery of natural gas deposits. Expansion of petroleum exports in the 1960s not only crowded out other exports, it actually reduced other exports disproportionately and fueled the fea...

  14. Paragonimus worm from a New Guinea native in 1926

    Institute of Scientific and Technical Information of China (English)

    Wenlin Wang; David Blair; Tian Min; Fang Li; Dianhua Wang

    2011-01-01

    Objective: To reobserve and research the specimen of Paragonimus worm found in the left lung of a New Guinea native in 1926, which was previously identified as Paragonimuswestermani Kerbert or Paragonimus ringeri Cobbold. Methods: Using reconstructive software and microscopy to observe some organs of the worm, and compared with other species of paragonimus. Results: The three dimensional (3D) views of ovary and two testes of New Guinea specimen showed that the ovary was clearly divided into six lobes. These two testes were situated oppositely in the body. One teste was divided into four branches, while another was divided into five. The cuticular spines were arranged in groups over the entire skin covered in a slide, each group was consisted of two to four single spine. Conclusions: Based on 3D views and measurements, we reclassified it as Paragonimus siamensis. This was also the first report of human case infected by Paragonimus siamensis.

  15. Robert Koch redux: malaria immunology in Papua New Guinea.

    Science.gov (United States)

    Stanisic, D I; Mueller, I; Betuela, I; Siba, P; Schofield, L

    2010-08-01

    Over a century ago, the malaria expedition of the brilliant microbiologist Robert Koch to the Dutch East Indies (Indonesia) and German New Guinea (now Papua New Guinea, or PNG), resulted in profound observations that are still central to our current understanding of the epidemiology and acquisition of immunity to the malaria parasite Plasmodium. The tradition of malaria research in PNG pioneered by Koch continues to this day, with a number of recent studies still continuing to elucidate his original concepts and hypotheses. These include age and exposure-related acquisition of immunity, species-specific and cross-species immunity, correlates of protective immunity and determining the prospects for anti-malaria vaccines. PMID:20626817

  16. The preparation of recombinant interleukin-6 and its protection for irradiated guinea-pigs

    International Nuclear Information System (INIS)

    Objective: To purify recombinant human interleukin-6 from gene-engineered E. coli and study the effects of IL-6 on survival period and platelet count of irradiated guinea-pigs. Methods: Recombinant human IL-6 was expressed in gene-engineered E. coli and purified with reversed phase chromatography. Purified IL-6 was then administered to irradiated guinea-pig. Results: IL-6 could significantly prolong the survival period and increase the platelet count of irradiated guinea-pigs. Conclusion: IL-6 showed its effective protection for irradiated guinea-pigs

  17. Changes of gastrointestinal myoelectric activity and bile acid pool size after cholecystectomy in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Xue-Mei Zhang; Lei Dong; Li-Na Liu; Bi-Xia Chang; Qian He; Qian Li

    2005-01-01

    AIM: To investigate the bile acid pool size after cholecystectomy whether or not correlated to the gastrointestinal migrating myoelectric complex (MMC) in guinea pigs.METHODS: Gallbladder motilities were assessed before cholecystectomy. Furthermore, we continuously monitored interdigestive gastrointestinal motilities using bipolar electrodes in conscious guinea pigs before and after surgery at 4 wk in standard diet group and high cholesterol diet (cholesterol gallstone) group. Total bile acid pool sizes were measured by isotope dilution method at meantime.RESULTS: After cholecystectomy, there were parallel falls in duration of phase Ⅰ, Ⅱ, Ⅲ and MMC cycle duration but increase in amplitude in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones. However, There were not significantly differences. On the other hand, the bile acid pool was definitely small in the GS guinea pigs compared to normal guinea pigs and became slightly smaller after cholecystectomy. Similarly, bile acid in gallbladder bile, fecal bile acid was slightly increased in GS guinea pigs after cholecystectomy, to the same degree as normal. These differences, however, were not significant.CONCLUSION: It is concluded that in the guinea pigs with normal gallbladder function, and in the guinea pigs with cholesterol stones: (1) Cholecystectomy produce a similar but less marked trend in bile acid pool; and (2) MMC are linked to enterohepatic circulation of bile acids, rather than surgery, which is consistent with changes of the bile acid pool size. As a result, gastrointestinal dyskinesia is not involved in occurrence of postcholecystectomy syndrome.

  18. The present use of guinea pigs for chiropractic research *

    OpenAIRE

    McGregor, Marion; Wiles, Michael R.; Grice, Adrian S.

    1980-01-01

    The necessity for an animal model in chiropractic research is considered and a short review of previous experimentation of manipulation on animals is presented. The guinea pig is proposed as a suitable animal model, and research into its suitability is presented. Analysis includes the animal’s physical characteristics, the choice of anesthetic and parametric and roentgenographic evaluation. A device for supporting the anesthetized animal during standard and motion roentgenographic examination...

  19. Child health and mortality in Guinea-Bissau

    DEFF Research Database (Denmark)

    Kovsted, Jens Anders; Pörtner, Claus Christian; Tarp, Finn

    2002-01-01

    This paper studies factors that influence child health in Bissau, the capital of Guinea-Bissau. This environment is characterised by high infant mortality, but not by malnutrition. We show that although maternal education is important in determining child health and mortality this effect diminishes...... or disappears when health knowledge is introduced as an explanatory variable. It emerges that health knowledge has large and positive effects on both child mortality and health when instrumented for to capture endogeneity...

  20. Pathogenesis of enteritis necroticans in Papula New Guinea.

    Science.gov (United States)

    Lawrence, G; Walker, P D

    1976-01-17

    It is suggested that enteritis necroticans occurs in the people of the Highlands of Papua New Guinea because they have low levels of digestive proteases in the intestinal lumen. These low protease levels are the result of a low-protein diet and the presence of heat-stable trypsin inhibitors in sweet potatato, the dietary staple. Low proteolytic activity allows the B toxin of Clostridium welchii type C, which is extremely susceptible to proteolysis, to initiate the disease.

  1. Feeding ecology of wintering terns in Guinea-Bissau

    NARCIS (Netherlands)

    Brenninkmeijer, A.; Stienen, E.W.M.; Klaassen, M.; Kersten, M.

    2002-01-01

    We studied the feeding ecology of little tTerns Sterna albifrons, sandwich terns S. sandvicensis and royal terns S. maxima in the Archipélago dos Bijagós (11°40'N, 15°45'W) in Guinea-Bissau (West Africa) during the winter of 1992/1993. More than 95 of all prey taken by these terns were roundfish, ra

  2. Pathogenesis of enteritis necroticans in Papula New Guinea.

    Science.gov (United States)

    Lawrence, G; Walker, P D

    1976-01-17

    It is suggested that enteritis necroticans occurs in the people of the Highlands of Papua New Guinea because they have low levels of digestive proteases in the intestinal lumen. These low protease levels are the result of a low-protein diet and the presence of heat-stable trypsin inhibitors in sweet potatato, the dietary staple. Low proteolytic activity allows the B toxin of Clostridium welchii type C, which is extremely susceptible to proteolysis, to initiate the disease. PMID:54640

  3. Feeding, ranging and social organisation of the Guinea baboon

    OpenAIRE

    Sharman, Martin John

    1982-01-01

    Before this study, the Guinea or Western baboon, Papio papio, was almost unknown in its natural environment. This thesis reports a nineteen-month field study of two troops of P. papio carried out in south-eastern Senegal. The monkeys were followed on foot, and aspects of their feeding, ranging and social behaviour were recorded. The troops were censused whenever possible. Both study groups, and other troops in the area, were found to be unusually large by comparison with other known troop...

  4. Effects of Ramosetron on Gastrointestinal Transit of Guinea Pig

    OpenAIRE

    Park, Yoo Mi; Lee, Young Ju; Lee, Young Ho; Kim, Tae Il; Park, Hyojin

    2013-01-01

    Background/Aims A selective 5-hydroxytryptamine (5-HT) type 3 receptor antagonist, ramosetron, inhibits stress-induced abnormal defecation in animals and is currently used as a therapeutic drug for irritable bowel syndrome with diarrhea. The aim of this study is to investigate the effect of ramosetron on altered gastrointestinal (GI) transit. Methods Male guinea pigs weighing approximately 300 g were used. The effect of ramosetron was investigated on altered GI transit induced by thyrotropin-...

  5. Papua New Guinea: multi-level awareness campaign.

    Science.gov (United States)

    1980-01-01

    The Population Awareness Campaign in Papua New Guinea has been launched as a nationwide population education effort. Provinical workshops will be held for local leaders and community groups to create an awareness of the ways in which rapid population growth interferes with development efforts. Other activities involving more specific family planning-related messages will be films, radio programs, and plays in the Pidgin language. These are all designed to air in rural areas.

  6. Economic modelling of plant germplasm collections in Papua New Guinea

    OpenAIRE

    Godden, David P.; Kennedy, John O.S.; Kambuou, Rosa N.

    1997-01-01

    Papua New Guinea has major ex situ field collections of plant genetic material in its major staple food crops (aibika, banana, cassava, sago, sweet potato, taro, yams). The PNG Government has become concerned at the cost of maintaining these collections. With limited germplasm conservation resources available, difficult choices must be made as to which plants to maintain. What resources should be devoted to maintaining plant genetic diversity in the wild or in collections. How should these re...

  7. Analysing multidimensional poverty in Guinea: A fuzzy set approach

    OpenAIRE

    Diallo, F.L.

    2010-01-01

    This paper aims at studying the multidimensional aspect of poverty in Guinea taking into account both the monetary and non monetary dimensions of poverty. We use data from the Full Base Survey on Poverty Assessment (FBSPA 2002-2003). The methodology relies on the fuzzy set approach of Dagum and Costa (2004) which is supplemented by the decomposition methods of Mussard and Pi Alperin (2005). The main results that emerge are: i) the identification of the key variables associated with poverty, i...

  8. Prehistoric human impact on rainforest biodiversity in highland New Guinea.

    Science.gov (United States)

    Haberle, Simon G

    2007-02-28

    In the highlands of New Guinea, the development of agriculture as an indigenous innovation during the Early Holocene is considered to have resulted in rapid loss of forest cover, a decrease in forest biodiversity and increased land degradation over thousands of years. But how important is human activity in shaping the diversity of vegetation communities over millennial time-scales? An evaluation of the change in biodiversity of forest habitats through the Late Glacial transition to the present in five palaeoecological sites from highland valleys, where intensive agriculture is practised today, is presented. A detailed analysis of the longest and most continuous record from Papua New Guinea is also presented using available biodiversity indices (palynological richness and biodiversity indicator taxa) as a means of identifying changes in diversity. The analysis shows that the collapse of key forest habitats in the highland valleys is evident during the Mid - Late Holocene. These changes are best explained by the adoption of new land management practices and altered disturbance regimes associated with agricultural activity, though climate change may also play a role. The implications of these findings for ecosystem conservation and sustainability of agriculture in New Guinea are discussed. PMID:17255031

  9. Effects of inhaled hexamethylene diisocyanate (HDI) on guinea pig cholinesterases.

    Science.gov (United States)

    Karol, M H; Hansen, G A; Brown, W E

    1984-04-01

    Hexamethylene diisocyanate, HDI, a starting material in the production of many polyurethane products, was found to inhibit stoichiometrically mammalian and electric eel cholinesterases in an in vivo system (W. E. Brown, A. H. Green, M. H. Karol, and Y. Alarie , 1982, Toxicol . Appl. Pharmacol. 62, 45-52). The current study examined in vivo effects on guinea pig cholinesterases resulting from inhalation of HDI. Guinea pigs were exposed to atmospheres of 0.5, 1.8, or 4.0 ppm HDI (ceiling value = 0.02 ppm) for up to 6 hr. Blood samples were drawn prior to exposure and at specified times during exposure. No inhibition of serum cholinesterase was detected following exposure to 0.5 ppm HDI for 6 hr, to 1.8 ppm HDI for 2 hr, or to 4.0 ppm HDI for 3 hr. Similarly, no inhibition was detected when erythrocytes from each blood sample were assayed for acetylcholinesterase activity. Last, animals were sacrificed and cholinesterase activity determined in bronchial lavage fluid. Enzyme levels of HDI-exposed animals were not significantly different (P greater than 0.05) from those of control animals exposed to water vapor. In conclusion, although in vitro experiments had demonstrated potent anticholinesterase activity by HDI, in vivo inhalation exposure of guinea pigs to HDI at concentrations 25-200 times above the recommended (ACGIH) ceiling value did not produce measurable inhibition of cholinesterase activity. PMID:6724200

  10. Studies of guinea pig immunoglobulin isotype, idiotype and antiidiotype

    Energy Technology Data Exchange (ETDEWEB)

    Tirrell, S.M.

    1988-01-01

    Immunization of Guinea pigs with diphtheria toxoid generated antibodies of the IgG class that were capable of neutralizing native toxin in vivo. Sera from these animals were used to affinity purify idiotypic antibodies (AB1). AB1 vaccines derived from the IgG1 class and from F(ab{prime}){sub 2} of IgG1 + IgG2 (IgG1/2) classes were effective in inducing a syngeneic anti-idiotype (AB2) response. Animals immunized with AB1 consisting of both IgG1/2 did not elicit a detectable AB2 response. Binding of homologous {sup 125}I-F(ab{prime}){sub 2} (AB1) to the antiidiotype was inhibited 90% in the presence of DT.F(ab{prime}){sub 2} derived from preimmune serum or had no inhibitory effects on the idiotype-antiidiotype interactions. Two groups of outbred guinea pigs were vaccinated with alum absorbed F(ab{prime}){sub 2} of anti-idiotype IgG1/2 (AB2). Of the ten animals inoculated with AB2, three tested positive by RIA against {sup 125}I-DT. Two of the RIA positive sera contained antibodies that neutralized diphtheria toxin in a rabbit intracutaneous assay. Purification of guinea pig IgG by protein A-Sepharose affinity chromatography resulted in the separation of three distinct IgG populations.

  11. New genus of diminutive microhylid frogs from Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Fred Kraus

    2010-06-01

    Full Text Available A new genus of diminutive (10.1-11.3 mm microhylid frogs is described from New Guinea that is unique in its combination ofonly seven presacral vertebrae, a reduced phalangeal formula that leaves the first fingers and first toes as vestigial nubs, and reduction of the prepollex and prehallux to single elements. Relationships to other genera are unknown, but overall similarity suggests some relationship to Cophixalus, although that genus also differs in some muscle characters and likely remains paraphyletic. The new genus contains two species, which are among the smallest known frogs in the world. Their miniaturization may be related to their inhabiting leaf litter, exploitation of which may for small size. The new genus is currently known only from one mountaintop in the southeasternmost portion of New Guinea and another on a nearby island. This region is part of the East Papuan Composite Terrane and, should this lineage prove endemic to that region, it may suggest that it originated prior to that geological unit’s docking with mainland New Guinea at 23–29 MY.

  12. Coral settlement on a highly disturbed equatorial reef system.

    Directory of Open Access Journals (Sweden)

    Andrew G Bauman

    Full Text Available Processes occurring early in the life stages of corals can greatly influence the demography of coral populations, and successful settlement of coral larvae that leads to recruitment is a critical life history stage for coral reef ecosystems. Although corals in Singapore persist in one the world's most anthropogenically impacted reef systems, our understanding of the role of coral settlement in the persistence of coral communities in Singapore remains limited. Spatial and temporal patterns of coral settlement were examined at 7 sites in the southern islands of Singapore, using settlement tiles deployed and collected every 3 months from 2011 to 2013. Settlement occurred year round, but varied significantly across time and space. Annual coral settlement was low (~54.72 spat m(-2 yr(-1 relative to other equatorial regions, but there was evidence of temporal variation in settlement rates. Peak settlement occurred between March-May and September-November, coinciding with annual coral spawning periods (March-April and October, while the lowest settlement occurred from December-February during the northeast monsoon. A period of high settlement was also observed between June and August in the first year (2011/12, possibly due to some species spawning outside predicted spawning periods, larvae settling from other locations or extended larval settlement competency periods. Settlement rates varied significantly among sites, but spatial variation was relatively consistent between years, suggesting the strong effects of local coral assemblages or environmental conditions. Pocilloporidae were the most abundant coral spat (83.6%, while Poritidae comprised only 6% of the spat, and Acroporidae <1%. Other, unidentifiable families represented 10% of the coral spat. These results indicate that current settlement patterns are reinforcing the local adult assemblage structure ('others'; i.e. sediment-tolerant coral taxa in Singapore, but that the replenishment capacity

  13. Coral settlement on a highly disturbed equatorial reef system.

    Science.gov (United States)

    Bauman, Andrew G; Guest, James R; Dunshea, Glenn; Low, Jeffery; Todd, Peter A; Steinberg, Peter D

    2015-01-01

    Processes occurring early in the life stages of corals can greatly influence the demography of coral populations, and successful settlement of coral larvae that leads to recruitment is a critical life history stage for coral reef ecosystems. Although corals in Singapore persist in one the world's most anthropogenically impacted reef systems, our understanding of the role of coral settlement in the persistence of coral communities in Singapore remains limited. Spatial and temporal patterns of coral settlement were examined at 7 sites in the southern islands of Singapore, using settlement tiles deployed and collected every 3 months from 2011 to 2013. Settlement occurred year round, but varied significantly across time and space. Annual coral settlement was low (~54.72 spat m(-2) yr(-1)) relative to other equatorial regions, but there was evidence of temporal variation in settlement rates. Peak settlement occurred between March-May and September-November, coinciding with annual coral spawning periods (March-April and October), while the lowest settlement occurred from December-February during the northeast monsoon. A period of high settlement was also observed between June and August in the first year (2011/12), possibly due to some species spawning outside predicted spawning periods, larvae settling from other locations or extended larval settlement competency periods. Settlement rates varied significantly among sites, but spatial variation was relatively consistent between years, suggesting the strong effects of local coral assemblages or environmental conditions. Pocilloporidae were the most abundant coral spat (83.6%), while Poritidae comprised only 6% of the spat, and Acroporidae coral spat. These results indicate that current settlement patterns are reinforcing the local adult assemblage structure ('others'; i.e. sediment-tolerant coral taxa) in Singapore, but that the replenishment capacity of Singapore's reefs appears relatively constrained, which could lead

  14. Equatorial electrojet in the south Atlantic anomaly region

    Indian Academy of Sciences (India)

    R G Rastogi; H Chandra; N B Trivedi; V Doumbia

    2011-04-01

    Features of the equatorial electrojet are studied at Sao Luiz (2.6°S, 44.2°W, inclination −0.25°) in eastern Brazil and Sikasso (11.3°N, 5.7°W, inclination 0.1°) in the western African sector. The stations are situated on either side of the lowest magnetic field intensity in the region of rapid changes in the declination. The daily variations of X at the two stations are almost similar with the peak around noon with maximum values during equinoxes and minimum values during J-solstices. Daily variations of Y differ with the maximum deviation of about −35 nT around noon at Sao Luiz and much smaller value of about −10 nT around 14 h LT for Sikasso. The direction of the vector varies from 15°W of north at 08 h to more than 30°W of north at 17 h for Sao Luiz and from 14°E of north to 25°W of north at 18 h for Sikasso. The plot of the deviations in X and Y at different hours for the two stations shows the points along narrow ellipses with major axis aligned along 22°W of north for Sao Luiz and along 3°W of north for Sikasso as compared to declination of 20°W for Sao Luiz and 6°W for Sikasso. The deviations in X at the two stations are fairly well correlated.

  15. Engineering activities on the ITER representative diagnostic equatorial port plug

    International Nuclear Information System (INIS)

    Most of ITER diagnostic systems are integrated in port plugs, which are water cooled stainless steel structures inserted into the vacuum vessel ports. The port plug must provide basic functions such as neutron and gamma shielding, supporting the first wall armour (BSM), closing the vacuum vessel ports, while supporting the diagnostic equipments. ITER diagnostic port plug must resist a severe environment like high temperature due to neutron interaction with the structures and high electromechanical loading during disruptions events. CEA has contributed to the design and integration tasks in the frame of the representative equatorial port plug EQ no. 01, in particular on the engineering, structural and thermal finite element analysis. These detailed analyses have highlighted some design issues which were worked out through different solutions. This paper contains a description of the engineering activities performed such as: -The static mechanical calculations of the top plate closure system under disruption load. -The static mechanical calculations of the BSM attachment to the port plug. These two first studies led to design changes proposals which significantly improved the behaviour of the structures but also showed that the safety margin with respect to design limits is quite low. -The design of a Diagnostic Shield Module (DSM) integrated inside the port plug and a proposition of attachment scheme, with respect to disruption loads. The manufacturing of the DSM has been taken into account, as well as diagnostic integration inside the structure and maintenance aspects. -The thermal assessment of the port plug under neutronic load during normal operation, with the optimization of the cooling system. The maximum temperature calculated in normal operation has been reduced from 900 deg. C to less than 400 deg. C in the front plate; and the cooling arrangement at the back of the port plug has been simplified without important temperature increase.

  16. Interstitial cells of Cajal and Auerbach's plexus. A scanning electron microscopical study of guinea-pig small intestine

    DEFF Research Database (Denmark)

    Jessen, Harry; Thuneberg, Lars

    1991-01-01

    Anatomy, interstitial cells of Cajal, myenteric plexus, small intestine, guinea-pig, scanning electron microscopy......Anatomy, interstitial cells of Cajal, myenteric plexus, small intestine, guinea-pig, scanning electron microscopy...

  17. CLIMATOLOGICAL VARIATION OF GLOBAL CROSS-EQUATORIAL FLOWS FOR THE PERIOD 1948-2004

    Institute of Scientific and Technical Information of China (English)

    SHI Neng; FENG Guo-lin; GU Jun-qiang; GU De-jun; YU Jin-Hua

    2007-01-01

    By using monthly NCEP/NCAR meridional gridpoint wind data at the levels of 1000, 850, 700,600, 500, 400, 300, 200, 150 and 100 hPa from 1948 to 2004, the intensity of global cross-equatorial flows is calculated. The spatial and temporal variation of global cross-equatorial flows at the 850-hPa level are shown and discussed. The results show that the strength of the 850-hPa global cross-equatorial flows represent obvious long-term variation and interdecadal change during the period. Evidence suggests that the cross-equatorial flow of the passages at 45 - 50 °E in June to August, 105 - 115 °E in May to September,130 - 140 °E in May to September and May to November and 20 - 25 °E in February to April intensified and that the cross-equatorial flow of the passages at 50 - 35 °W in June to August weaken in the past 57 years, with an increase of 0.25m/s/10a for summer Somali Jet and increase of 0.32 m/s/10a for crossequatorial flow at 130 - 140 °E in May to September The results of Singular Spectrum Analysis (SSA) for the time series indicate that for the cross-equatorial flow at 850 hPa, the interdecadal and long-term trend changes are 35% - 45%, and the interannual variation is no more than 30%, in variance contribution. The results also reveal that the interannual variation of intensity of the summer cross-equatorial flows in the Pacific is significantly correlated with Southern Oscillation. With weak Southern Oscillation, strong crossequatorial flows in Pacific will happen, though the summer Somali Jet is only a little positively correlated with North Atlantic Oscillation (NAD).

  18. Phase locking of equatorial Atlantic variability through the seasonal migration of the ITCZ

    Science.gov (United States)

    Richter, Ingo; Xie, Shang-Ping; Morioka, Yushi; Doi, Takeshi; Taguchi, Bunmei; Behera, Swadhin

    2016-07-01

    The equatorial Atlantic is marked by significant interannual variability in sea-surface temperature (SST) that is phase-locked to late boreal spring and early summer. The role of the atmosphere in this phase locking is examined using observations, reanalysis data, and model output. The results show that equatorial zonal surface wind anomalies, which are a main driver of warm and cold events, typically start decreasing in June, despite SST and sea-level pressure gradient anomalies being at their peak during this month. This behavior is explained by the seasonal northward migration of the intertropical convergence zone (ITCZ) in early summer. The north-equatorial position of the Atlantic ITCZ contributes to the decay of wind anomalies in three ways: (1) horizontal advection associated with the cross-equatorial winds transports air masses of comparatively low zonal momentum anomalies from the southeast toward the equator. (2) The absence of deep convection leads to changes in vertical momentum transport that reduce the equatorial wind anomalies at the surface, while anomalies aloft remain relatively strong. (3) The cross-equatorial flow is associated with increased total wind speed, which increases surface drag and deposit of momentum into the ocean. Previous studies have shown that convection enhances the surface wind response to SST anomalies. The present study indicates that convection also amplifies the surface zonal wind response to sea-level pressure gradients in the western equatorial Atlantic, where SST anomalies are small. This introduces a new element into coupled air-sea interaction of the tropical Atlantic.

  19. Multiple embryos, multiple nepionts and multiple equatorial layers in Cycloclypeus carpenteri.

    Science.gov (United States)

    Briguglio, Antonino; Kinoshita, Shunichi; Wolfgring, Erik; Hohenegger, Johann

    2016-04-01

    In this study, 17 specimens of Cycloclypeus carpenteri have been analyzed by means of microCT scanning. We used CT scanning technique as it enables the visualization and the quantifications of internal structures of hollow specimens without their destruction. It has been observed that many specimens possessing the natural morphology of this taxon, actually contain multiple embryos (up to 16 in one single specimen) and, in some few cases, multiple nepionts each with its own heterosteginid chambers (up to three separated nepionts). The diameter of each proloculus has been measured, and as a result, they are very variable even within the same specimen, therefore questioning the long known theory that schizonts have smaller proloculi than gamonts and also questioning the fact that proloculi in the same species should all have comparable size. Furthermore, we have observed the presence of additional equatorial planes on several specimens. Such additional planes are always connected to what seems to be the main equatorial plane. Such connections are T-shaped and are located at the junction between two equatorial layers; these junctions are made by a chamberlet, which possesses an unusually higher number of apertures. The connections between equatorial planes are always perfectly synchronized with the relative growth step and the same chamber can be therefore followed along the multiple equatorial planes. Apparently there is a perfect geometric relationship between the creation of additional equatorial planes and the position of the nepionts. Whenever the nepionts are positioned on different planes, additional planes are created and the angle of the nepionts is related to the banding angle of the equatorial planes. The presence of additional planes do not hamper the life of the cell, on the contrary, it seems that the cell is still able to build nicely shaped chamberlets and, after volumetric calculations, it seems all specimens managed to keep their logistic growth

  20. Using ionospheric scintillation observations for studying the morphology of equatorial ionospheric bubbles

    Science.gov (United States)

    Dandekar, B. S.; Groves, K. M.

    2004-06-01

    For a study of the equatorial ionosphere, ionospheric scintillation data at VHF and L-band frequencies have been routinely collected by ground-based receivers at Ancon, Peru, Antofagasta, Chile, and Ascension Island, UK, since May 1994. The receivers routinely monitor VHF transmissions from two geosynchronous satellites located at 100°W longitude and 23°W longitude, and L-band signals from satellites located at 75°W longitude and 15°W longitude. This combination provides a network of seven usable, reasonably separated links for monitoring ionospheric equatorial bubble activity in the South American longitude sector. A data set of seven years covering the period from 1995 to 2001 was studied to determine the temporal, diurnal, and seasonal behavior of equatorial bubbles. The results of our statistical study are presented here. In general the equatorial ionospheric bubble activity shows a strong systematic and primary dependence in temporal, diurnal, and seasonal variation, and a secondary weak dependence on geomagnetic and solar flux activity. At present, the dependence on solar and magnetic activity is not usable for near-time and short-term prediction of the equatorial bubble activity. Equatorial bubbles usually start 1 hour after sunset, the activity peaks before local midnight, and vanishes by early morning. The activity peaks in the months of November and January-February and is practically absent (weak) from May to August. On a daily basis on the average one sees 1 to 3 bubbles. The duration of bubbles is about 70 min, and the time spacing between the bubbles is 1 to 2 hours. The bubble activity in general follows the phase of solar cycle activity. The observed systematic behavior of the equatorial bubbles allows for a now cast and short-term forecast of the bubble activity in the South American sector.

  1. Metal quotas of plankton in the equatorial Pacific Ocean

    Science.gov (United States)

    Twining, Benjamin S.; Baines, Stephen B.; Bozard, James B.; Vogt, Stefan; Walker, Elyse A.; Nelson, David M.

    2011-03-01

    The micronutrient metals Mn, Fe, Co, Ni and Zn are required for phytoplankton growth, and their availability influences ocean productivity and biogeochemistry. Here we report the first direct measurements of these metals in phytoplankton and protozoa from the equatorial Pacific Ocean. Cells representing 4 functional groups (diatoms, autotrophic flagellates, heterotrophic flagellates and autotrophic picoplankton) were collected from the surface mixed layer using trace-metal clean techniques during transects across the equator at 110°W and along the equator between 110°W and 140°W. Metal quotas were determined for individual cells with synchrotron x-ray fluorescence microscopy, and cellular stoichiometries were calculated relative to measured P and S, as well as to C calculated from biovolume. Bulk particulate (>3 μm) metal concentrations were also determined at 3 stations using inductively coupled plasma mass spectrometry for comparison to single-cell stoichiometries. Phosphorus-normalized Mn, Fe, Ni and Zn ratios were significantly higher in diatoms than other cell types, while Co stoichiometries were highest in autotrophic flagellates. The magnitude of these effects ranged from approximately 2-fold for Mn in diatoms and autotrophic flagellates to nearly an order of magnitude for Fe in diatoms and picoplankton. Variations in S-normalized metal stoichiometries were also significant but of lower magnitude (1.4 to 6-fold). Cobalt and Mn quotas were 1.6 and 3-fold higher in autotrophic than heterotrophic flagellates. Autotrophic picoplankton were relatively enriched in Ni but depleted in Zn, matching expectations based on known uses of these metals in prokaryotes and eukaryotes. Significant spatial variability in metal stoichiometries was also observed. At two stations deviations in Fe stoichiometries reflected features in the dissolved Fe distribution. At these same stations, high Ni stoichiometries in autotrophic flagellates were correlated with elevated ammonium

  2. Halocarbon emissions and sources in the equatorial Atlantic Cold Tongue

    Directory of Open Access Journals (Sweden)

    H. Hepach

    2015-04-01

    Full Text Available Halocarbons from oceanic sources contribute to halogens in the troposphere, and can be transported into the stratosphere where they take part in ozone depletion. This paper presents distribution and sources in the equatorial Atlantic from June and July 2011 of the four compounds bromoform (CHBr3, dibromomethane (CH2Br2, methyl iodide (CH3I and diiodomethane (CH2I2. Enhanced biological production during the Atlantic Cold Tongue (ACT season, indicated by phytoplankton pigment concentrations, led to elevated concentrations of CHBr3 of up to 44.7 pmol L−1 and up to 9.2 pmol L−1 for CH2Br2 in surface water, which is comparable to other tropical upwelling systems. While both compounds correlated very well with each other in the surface water,CH2Br2 was often more elevated in greater depth than CHBr3, which showed maxima in the vicinity of the deep chlorophyll maximum. The deeper maximum of CH2Br2 indicates an additional source in comparison to CHBr3 or a slower degradation of CH2Br2. Concentrations of CH3I of up to 12.8 pmol L−1 in the surface water were measured. In contrary to expectations of a predominantly photochemical source in the tropical ocean, its distribution was mostly in agreement with biological parameters, indicating a~biological source. CH2I2 was very low in the near surface water with maximum concentrations of only 3.7 pmol L−1, and the observed anticorrelation with global radiation was likely due to its strong photolysis. CH2I2 showed distinct maxima in deeper waters similar to CH2Br2. For the first time, diapycnal fluxes of the four halocarbons from the upper thermocline into and out of the mixed layer were determined. These fluxes were low in comparison to the halocarbon sea-to-air fluxes. This indicates that despite the observed maximum concentrations at depth, production in the surface mixed layer is the main oceanic source for all four compounds and has an influence on emissions into the atmosphere. The calculated

  3. Guest investigator program study: Physics of equatorial plasma bubbles

    Science.gov (United States)

    Tsunoda, Roland T.

    1994-01-01

    Plasma bubbles are large-scale (10 to 100 km) depletions in plasma density found in the night-time equatorial ionosphere. Their formation has been found to entail the upward transport of plasma over hundreds of kilometers in altitude, suggesting that bubbles play significant roles in the physics of many of the diverse and unique features found in the low-latitude ionosphere. In the simplest scenario, plasma bubbles appear first as perturbations in the bottomside F layer, which is linearly unstable to the gravitationally driven Rayleigh-Taylor instability. Once initiated, bubbles develop upward through the peak of the F layer into its topside (sometimes to altitudes in excess of 1000 km), a behavior predicted by the nonlinear form of the same instability. While good general agreement has been found between theory and observations, little is known about the detailed physics associated with plasma bubbles. Our research activity centered around two topics: the shape of plasma bubbles and associated electric fields, and the day-to-day variability in the occurrence of plasma bubbles. The first topic was pursued because of a divergence in view regarding the nonlinear physics associated with plasma bubble development. While the development of perturbations in isodensity contours in the bottomside F layer into plasma bubbles is well accepted, some believed bubbles to be cylinder-like closed regions of depleted plasma density that floated upward leaving a turbulent wake behind them (e.g., Woodman and LaHoz, 1976; Ott, 1978; Kelley and Ott, 1978). Our results, summarized in a paper submitted to the Journal of Geophysical Research, consisted of incoherent scatter radar measurements that showed unambiguously that the depleted region is wedgelike and not cylinderlike, and a case study and modeling of SM-D electric field instrument (EFI) measurements that showed that the absence of electric-field perturbations outside the plasma-depleted region is a distinct signature of wedge

  4. A Campaign to Study Equatorial Ionospheric Phenomena over Guam

    Science.gov (United States)

    Habash Krause, L.; Balthazor, R.; Dearborn, M.; Enloe, L.; Lawrence, T.; McHarg, M.; Petrash, D.; Reinisch, B. W.; Stuart, T.

    2007-05-01

    With the development of a series of ground-based and space-based experiments, the United States Air Force Academy (USAFA) is in the process of planning a campaign to investigate the relationship between equatorial ionospheric plasma dynamics and a variety of space weather effects, including: 1) ionospheric plasma turbulence in the F region, and 2) scintillation of radio signals at low latitudes. A Digisonde Portable Sounder DPS-4 will operate from the island of Guam (with a magnetic latitude of 5.6° N) and will provide measurements of ionospheric total electron content (TEC), vertical drifts of the bulk ionospheric plasma, and electron density profiles. Additionally, a dual-frequency GPS TEC/scintillation monitor will be located along the Guam magnetic meridian at a magnetic latitude of approximately 15° N. In campaign mode, we will combine these ground-based observations with those collected from space during USAFA's FalconSAT-3 and FalconSAT-5 low-earth orbit satellite missions, the first of which is scheduled to be active over a period of several months beginning in the 2007 calendar year. The satellite experiments are designed to characterize in situ irregularities in plasma density, and include measurements of bulk ion density and temperature, minority-to- majority ion mixing ratios, small scale (10 cm to 1 m) plasma turbulence, and ion distribution spectra in energy with sufficient resolution for observations of non-thermalized distributions that may be associated with velocity- space instabilities. Specific targets of investigation include: a) a comparison of plasma turbulence observed on- orbit with spread F on ionograms as measured with the Digisonde, b) a correlation between the vertical lifting of the ionospheric layer over Guam and the onset of radio scintillation activity along the Guam meridian at 15° N magnetic latitude, and c) a correlation between on-orbit turbulence and ionospheric scintillation at 15° N magnetic latitude. These relationships

  5. No iron fertilization in the equatorial Pacific Ocean during the last ice age.

    Science.gov (United States)

    Costa, K M; McManus, J F; Anderson, R F; Ren, H; Sigman, D M; Winckler, G; Fleisher, M Q; Marcantonio, F; Ravelo, A C

    2016-01-28

    The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the equatorial Pacific with iron during the last ice age--the Last Glacial Period (LGP)--but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the (232)Th proxy), phytoplankton productivity (using opal, (231)Pa/(230)Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ(15)N) from six cores in the central equatorial Pacific for the Holocene (0-10,000 years ago) and the LGP (17,000-27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region. Thus, ice-age iron fertilization in the

  6. No iron fertilization in the equatorial Pacific Ocean during the last ice age

    Science.gov (United States)

    Costa, K. M.; McManus, J. F.; Anderson, R. F.; Ren, H.; Sigman, D. M.; Winckler, G.; Fleisher, M. Q.; Marcantonio, F.; Ravelo, A. C.

    2016-01-01

    The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the equatorial Pacific with iron during the last ice age—the Last Glacial Period (LGP)—but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the 232Th proxy), phytoplankton productivity (using opal, 231Pa/230Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ15N) from six cores in the central equatorial Pacific for the Holocene (0-10,000 years ago) and the LGP (17,000-27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region. Thus, ice-age iron fertilization in the

  7. No iron fertilization in the equatorial Pacific Ocean during the last ice age.

    Science.gov (United States)

    Costa, K M; McManus, J F; Anderson, R F; Ren, H; Sigman, D M; Winckler, G; Fleisher, M Q; Marcantonio, F; Ravelo, A C

    2016-01-28

    The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the equatorial Pacific with iron during the last ice age--the Last Glacial Period (LGP)--but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the (232)Th proxy), phytoplankton productivity (using opal, (231)Pa/(230)Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ(15)N) from six cores in the central equatorial Pacific for the Holocene (0-10,000 years ago) and the LGP (17,000-27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region. Thus, ice-age iron fertilization in the

  8. Cloning, pharmacological characterization, and polymorphism screening of the guinea pig β2-adrenoceptor

    NARCIS (Netherlands)

    Oostendorp, Jaap; Meurs, Herman; Nelemans, S. Adriaan; Zaagsma, Johan; Kauffman, Henk F.; Postma, Dirkje S.; Boddeke, Hendrikus W.G.M.; Biber, Knut

    2002-01-01

    In asthma, beta(2)-adrenoceptor agonist responsiveness has been associated with Arg16Gly and Gln27Glu polymorphisms of the beta(2)-adrenoceptor. Since the guinea pig is extensively used as an animal model for asthma, we investigated the occurrence of possible polymorphism of the guinea pig beta(2)-a

  9. Interrelationships of Non-Formal Mother Tongue Education and Citizenship in Guinea and Senegal

    Science.gov (United States)

    Clemons, Andrea; Yerende, Eva

    2009-01-01

    Guinea and Senegal are multilingual countries that use French as a language of instruction in the formal educational sector with some significant exceptions. As in many other African countries, such exceptions in Guinea and Senegal, use local African languages primarily in the non-formal sector for a variety of purposes, such as adult literacy and…

  10. Isolation of viable Toxoplasma gondii from guinea fowl (Numida meleagris) and rabbits from Brazil

    Science.gov (United States)

    Toxoplasma gondii was isolated from a feral guinea fowl (Numida meleagris) and domestic rabbits from Brazil for the first time. Serum and brains from 10 guinea fowl and 21 rabbits from Brazil were examined for T. gondii infection. Antibodies to T. gondii were found in 2 of 10 fowl and 2 of 21 rabbit...

  11. Cartilage interposition in ossiculoplasty with hydroxylapatite prostheses : A histopathologic study in the guinea pig

    NARCIS (Netherlands)

    Meijer, AGW; Verheul, J; Albers, FWJ; Segenhout, HM

    2002-01-01

    In this experimental animal study, a cartilage disk was interposed between a synthetic middle ear prosthesis and the tympanic membrane in guinea pigs to investigate its effect on the extrusion process of the implant. Two groups of guinea pigs were studied. One group consisted of animals in which the

  12. Cartilage interposition in ossiculoplasty with hydroxylapatite prostheses - A histological study in the guinea pig

    NARCIS (Netherlands)

    Meijer, AGW; Verheul, J; Albers, FWJ; Segenhout, HM; Rosowski, JJ; Merchant, SN

    2000-01-01

    In this experimental animal study, a cartilage disc was interposed between a synthetic middle ear prosthesis and the tympanic membrane of guinea pigs to investigate its effect on the extrusion process of the implant. Two groups of guinea pigs were studied. One group consisted of animals in which the

  13. Reduced case fatality among hospitalized children during a war in Guinea-Bissau

    DEFF Research Database (Denmark)

    Sodemann, Morten; Veirum, Jens Erik; Biai, S;

    2004-01-01

    During a recent armed conflict in Guinea-Bissau, we observed a marked decline in the case fatality among hospitalized children at the only paediatric department in the country.......During a recent armed conflict in Guinea-Bissau, we observed a marked decline in the case fatality among hospitalized children at the only paediatric department in the country....

  14. Complete Genome Sequence of Pathogenic Guinea Pig Cytomegalovirus from Salivary Gland Homogenates of Infected Animals

    OpenAIRE

    Yang, Dongmei; Tamburro, Kristen; Dittmer, Dirk; Cui, Xiaohong; McVoy, Michael A.; Hernandez-Alvarado, Nelmary; Schleiss, Mark R.

    2013-01-01

    The sequence of guinea pig cytomegalovirus (GPCMV) was determined by direct sequencing of salivary gland homogenates obtained following sustained, serial in vivo passage of pathogenic virus in guinea pigs. The 233,501-nucleotide salivary gland (SG) genome was noted to have 11 differences compared to the tissue culture-passaged virus, although no variations were noted in putative protein coding sequences.

  15. Seismo-ionospheric coupling appearing as equatorial electron density enhancements observed via DEMETER electron density measurements

    Science.gov (United States)

    Ryu, K.; Lee, E.; Chae, J. S.; Parrot, M.; Pulinets, S.

    2014-10-01

    We report the processes and results of statistical analysis on the ionospheric electron density data measured by the Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) satellite over a period of 6 years (2005-2010), in order to investigate the correlation between seismic activity and equatorial plasma density variations. To simplify the analysis, three equatorial regions with frequent earthquakes were selected and then one-dimensional time series analysis between the daily seismic activity indices and the equatorial ionization anomaly (EIA) intensity indices, which represent relative equatorial electron density increase, were performed for each region. The statistically significant values of the lagged cross-correlation function, particularly in the region with minimal effects of longitudinal asymmetry, indicate that some of the very large earthquakes with M > 5.0 in the low-latitude region can accompany observable precursory and concurrent EIA enhancements, even though the seismic activity is not the most significant driver of the equatorial ionospheric evolution. The physical mechanisms of the seismo-ionospheric coupling is consistent with our observation, and the possibility of earthquake prediction using the EIA intensity variation is discussed.

  16. Excitation of equatorial Kelvin and Yanai waves by tropical cyclones in an ocean general circulation model

    Directory of Open Access Journals (Sweden)

    R. L. Sriver

    2013-01-01

    Full Text Available Tropical cyclones (TCs actively contribute to the dynamics of Earth's coupled climate system. They influence oceanic mixing rates, upper-ocean heat content, and air–sea fluxes, with implications for atmosphere and ocean dynamics on multiple spatial and temporal scales. Using an ocean general circulation model with modified surface wind forcing, we explore how TC winds can excite equatorial ocean waves in the tropical Pacific. We highlight a situation where three successive TCs in the western North Pacific region, corresponding to events in 2003, excite a combination of Kelvin and Yanai waves in the equatorial Pacific. The resultant thermocline adjustment significantly modifies the thermal structure of the upper equatorial Pacific and leads to eastward zonal heat transport. Observations of upper-ocean temperature by the Tropical Atmosphere Ocean (TAO buoy array and sea-level height anomalies using altimetry reveal wave passage during the same time period with similar properties to the modeled wave, although our idealized model methodology disallows precise identification of the TC forcing with the observed waves. Results indicate that direct oceanographic forcing by TCs may be important for understanding the spectrum of equatorial ocean waves, thus remotely influencing tropical mixing and surface energy budgets. Because equatorial Kelvin waves are closely linked to interannual variability in the tropical Pacific, these findings also suggest TC wind forcing may influence the timing and amplitude of El Niño events.

  17. Excitation of equatorial Kelvin and Yanai waves by tropical cyclones in an ocean general circulation model

    Directory of Open Access Journals (Sweden)

    R. L. Sriver

    2012-09-01

    Full Text Available Tropical cyclones (TCs actively contribute to the dynamics of Earth's coupled climate system. They influence oceanic mixing rates, upper-ocean heat content, and air-sea fluxes, with implications for atmosphere and ocean dynamics on multiple spatial and temporal scales. Using an ocean general circulation model with modified surface wind forcing, we explore how TC winds can excite equatorial ocean waves in the tropical Pacific. We highlight a situation where three successive TCs in the western North Pacific region, corresponding to events in 2003, excite a combination of Kelvin and Yanai waves in the equatorial Pacific. The resultant thermocline adjustment significantly modifies the thermal structure of the upper equatorial Pacific and leads to eastward zonal heat transport. Observations of upper-ocean temperature by the Tropical Atmosphere Ocean (TAO buoy array and sea-level height anomalies using altimetry reveal wave passage during the same time period with similar properties to the modeled wave, although our idealized model methodology disallows precise identification of the TC forcing with the observed waves. Results indicate that direct oceanographic forcing by TCs may be important for understanding the spectrum of equatorial ocean waves, thus remotely influencing tropical mixing and surface energy budgets. Because equatorial Kelvin waves are closely linked to interannual variability in the tropical Pacific, these findings also suggest TC wind forcing may influence the timing and amplitude of El Niño events.

  18. Equatorial Pacific Coral Geochemical Records Show Recent Weakening of the Walker Circulation

    Science.gov (United States)

    Carilli, J.; Mcgregor, H. V.; Gaudry, J. J.; Donner, S. D.; Gagan, M. K.; Stevenson, S. L.; Wong, H.; Fink, D.

    2014-12-01

    Equatorial Pacific ocean-atmosphere interactions affect climate globally, and a key component of the coupled system is the Walker Circulation, which is driven by sea surface temperature (SST) gradients across the equatorial Pacific. There is conflicting evidence as to whether the SST gradient and Walker Circulation have strengthened or weakened over the late 20th century. We present new records of SST and sea surface salinity (SSS) spanning 1959-2010 based on paired measurements of Sr/Ca and d18O in a massive Porites coral from Butaritari atoll in the Gilbert Islands, Republic of Kiribati, in the central-western equatorial Pacific. The records show 2-7 year variability correlated with the El Niño-Southern Oscillation (ENSO) and corresponding shifts in the extent of the Indo-Pacific Warm Pool, and decadal-scale signals related to the Pacific Decadal Oscillation. In addition, the Butaritari coral records reveal a small but significant increase in SST (0.39˚C) from 1959 to 2010 with no accompanying change in SSS, a trend that persists even when ENSO variability is removed. In contrast, larger increases in SST and SSS are evident in coral records from the equatorial Pacific Line Islands, located east of Butaritari. Taken together, the equatorial Pacific coral records suggest an overall reduction in the east-west SST and SSS gradient over the last several decades, and a recent weakening of the Walker Circulation.

  19. Response of the equatorial ionosphere to the geomagnetic DP 2 current system

    Science.gov (United States)

    Yizengaw, E.; Moldwin, M. B.; Zesta, E.; Magoun, M.; Pradipta, R.; Biouele, C. M.; Rabiu, A. B.; Obrou, O. K.; Bamba, Z.; Paula, E. R.

    2016-07-01

    The response of equatorial ionosphere to the magnetospheric origin DP 2 current system fluctuations is examined using ground-based multiinstrument observations. The interaction between the solar wind and magnetosphere generates a convection electric field that can penetrate to the ionosphere and cause the DP 2 current system. The quasiperiodic DP 2 current system, which fluctuates coherently with fluctuations of the interplanetary magnetic field (IMF) Bz, penetrates nearly instantaneously to the dayside equatorial region at all longitudes and modulates the electrodynamics that governs the equatorial density distributions. In this paper, using magnetometers at high and equatorial latitudes, we demonstrate that the quasiperiodic DP 2 current system penetrates to the equator and causes the dayside equatorial electrojet (EEJ) and the independently measured ionospheric drift velocity to fluctuate coherently with the high-latitude DP 2 current as well as with the IMF Bz component. At the same time, radar observations show that the ionospheric density layers move up and down, causing the density to fluctuate up and down coherently with the EEJ and IMF Bz.

  20. Marine and terrigenous origin of organic matter in modern sediments of the equatorial East Atlantic: the σ 13C and molecular record

    Science.gov (United States)

    Westerhausen, L.; Poynter, J.; Eglinton, G.; Erlenkeuser, H.; Sarnthein, M.

    1993-05-01

    The contributions of marine and terrigenous organic carbon in modern organic sediments from the equatorial East Atlantic was quantified, based on the stable carbon isotope composition standardized for sea surface temperature and water depth. In our binary σ 13C mixing model, the marine end member -26 ∞ is redefined at 23°C and 0 m water depth and the terrigenous end member, independent of SST and water depth, at - 26 ∞. Terrigenous carbon fractions account for more than 60% of total organic carbon (TOC) on the shelf off East Liberia and the Ivory Coast and off Gabon. On the upper slope the land-derived fraction decreases in general to less than 20% of the high TOC concentrations, which can reach 3.5 wt%. The distribution of plant wax n-alkanes (C 27, C 29, C 31) and C:N ratios do not parallel those of land-derived organic carbon, but may be controlled largely by carbon degradation and aeolian/aquatic sorting. The ratio of n-alkanols vs n-alkanes (HPA index) varies with water depth in a nonlinear mode. Since both groups of compounds stem from the same source, plant waxes, it is proposed that the HPA index is controlled mainly by degradation and to a lesser extent by sorting prior to degradation. Enhanced n-alkane concentrations (up to 580 μg/gTOC) in the Gambia Basin and in the central Guinea Basin clearly reflect the influx of aeolian organic matter from northeasterly trades near and below the Inter Tropical Convergence Zone (ITCZ). The particle flux from marine plankton is traced by high concentrations of both dinosterol, long-chain unsaturated methyl and ethyl ketones (C 37-C 39), and alkandiols in marine organic matter. Whereas alkenones, synthetized by prymnesiophyte algae generally, reflect upwelling-related productivity off-shore, dinosterol, synthetized by dinoflagellates, is enriched in near-shore areas of high marine productivity linked to fluvial fertilization. All marine biomarker groups show a surprisingly low concentration below the equatorial

  1. Characterization of fetal growth by repeated ultrasound measurements in the wild guinea pig (Cavia aperea).

    Science.gov (United States)

    Schumann, K; Guenther, A; Göritz, F; Jewgenow, K

    2014-08-01

    Fetal growth during pregnancy has previously been studied in the domesticated guinea pig (Cavia aperea f. porcellus) after dissecting pregnant females, but there are no studies describing the fetal growth in their wild progenitor, the wild guinea pig (C aperea). In this study, 50 pregnancies of wild guinea pig sows were investigated using modern ultrasound technique. The two most common fetal growth parameters (biparietal diameter [BPD] and crown-rump-length [CRL]) and uterine position were measured. Data revealed similar fetal growth patterns in the wild guinea pig and domesticated guinea pig in the investigated gestation period, although they differ in reproductive milestones such as gestation length (average duration of pregnancy 68 days), average birth weight, and litter mass. In this study, pregnancy lasted on average 60.2 days with a variance of less than a day (0.96 days). The measured fetal growth parameters are strongly correlated with each (R = 0.91; P pig.

  2. Characteristics of the global longitudinal effect in the nighttime equatorial anomaly

    International Nuclear Information System (INIS)

    Stable for every solstice characteristics of the global longitudinal effect in the nighttime equatorial anomaly under conditions of high solar activity are detected according to the data on external probing at the ''Interkosmos-19'' satellite. In particular, longitudinal variants NmF2, hmF2 and Ne in the external ionosphere over geomagnetic equator, positions of both anomaly ridges, the degree of development and asymmetry of the equatorial anomaly are detected. The equatorial nighttime anomaly is shown to be more developed there, where Ne maximum is observed due to the longitudinal effect in the middle latitudes of the summer hemisphere, i.e. in approximately 330 deg longitudes for summer solstice and 150-180 deg - for winter one

  3. Propagation of equatorial noise to low altitudes: Decoupling from the magnetosonic mode

    Science.gov (United States)

    Santolík, O.; Parrot, M.; Němec, F.

    2016-07-01

    Equatorial noise (often phenomenologically described as magnetosonic waves in the literature) is a natural electromagnetic emission, which is generated by instability of ion distributions and which can interact with electrons in the Van Allen radiation belts. We use multicomponent electromagnetic measurements of the DEMETER spacecraft to investigate if equatorial noise propagates inward down to the Earth. Analysis of a selected event recorded under disturbed geomagnetic conditions shows that equatorial noise can be observed at an altitude of 700 km, while propagating radially downward as a superposition of spectral lines from different distant sources observed at frequencies both below and above the local proton cyclotron frequency. Changes in the local ion composition encountered by the waves during their inward propagation disconnect the identified wave mode from the low-frequency magnetosonic mode. The local ion composition also induces a cutoff which prevents the waves from propagating down to the ground.

  4. On the mutual relationship of the equatorial electrojet, TEC and scintillation in the Peruvian sector

    Science.gov (United States)

    Khadka, Sovit M.; Valladares, Cesar; Pradipta, Rezy; Pacheco, Edgardo; Condor, Percy

    2016-06-01

    This paper presents the interrelationship between the equatorial electrojet (EEJ) strength, Global Positioning System (GPS)-derived total electron content (TEC), and postsunset scintillation from ground observations with the aim of finding reliable precursors of the occurrence of ionospheric irregularities. Mutual relationship studies provide a possible route to predict the occurrence of TEC fluctuation and scintillation in the ionosphere during the late afternoon and night respectively based on daytime measurement of the equatorial ionosphere. Data from ground based observations in the low latitudes of the west American longitude sector were examined during the 2008 solar minimum. We find a strong relationship exists between the noontime equatorial electrojet and GPS-derived TEC distributions during the afternoon mediated by vertical E × B drift via the fountain effect, but there is little or no relationship with postsunset ionospheric scintillation.

  5. First observational evidence for the connection between the meteoric activity and occurrence of equatorial counter electrojet

    Science.gov (United States)

    Vineeth, C.; Mridula, N.; Muralikrishna, P.; Kumar, K. K.; Pant, T. K.

    2016-09-01

    This paper presents the first direct observational evidence for the possible role of meteoric activity in the generation of the equatorial Counter Electrojets (CEJ), an enigmatic daytime electrodynamical process over the geomagnetic equatorial upper atmosphere. The investigation carried out using the data from Proton Precession Magnetometer and Meteor Wind Radar over a geomagnetic dip equatorial station, Trivandrum (8.5°N, 77°E, 0.5°N dip lat.) in India, revealed that the occurrence of the afternoon CEJ events during a month is directly proportional to the average monthly meteor counts over this location. The observation is found to be very consistent during the considered period of study, i.e the years 2006 and 2007. The study vindicates that the meteor showers play a major role in setting up the background condition conducive for the generation of CEJ by reducing the strength of the upward polarization field.

  6. Investigation of height gradient in vertical plasma drift at equatorial ionosphere using multifrequency HF Doppler radar

    Science.gov (United States)

    Prabhakaran Nayar, S. R.; Sreehari, C. V.

    2004-12-01

    A multifrequency HF Doppler radar installed at the magnetic equatorial station Trivandrum provides an opportunity to study the height gradient in vertical plasma drift at the bottomside of equatorial F region during evening time. The multifrequency radar gives near-simultaneous observation of vertical plasma drift at three close by F region heights above the sounding station. The height gradient of the vertical drift shows a negative value during the prereversal enhancement (PRE) period and turns to positive value after the prereversal enhancement. The average height gradient in vertical plasma drift remains negative around PRE and its magnitude decreases with altitude, below F peak. This could be a clear-cut manifestation of the curl-free nature of the low-latitude electric field, and it could also indicate a partial signature of the postsunset velocity vortex at the equatorial F region. The magnitude of the mean height gradient around PRE exhibits a seasonal variation.

  7. Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs.

    Science.gov (United States)

    Clay, Emlyn; Patacchini, Riccardo; Trevisani, Marcello; Preti, Delia; Branà, Maria Pia; Spina, Domenico; Page, Clive

    2016-04-01

    Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levodropropizine. In contrast to the guinea pig, hypertussive responses in the rabbit were not inhibited by bronchodilator drugs (β2 agonists or muscarinic receptor antagonists), suggesting that the observed hypertussive state was not secondary to bronchoconstriction in this species. The ozone-induced hypertussive response in the rabbit was inhibited by chronic pretreatment with capsaicin, suggestive of a sensitization of airway sensory nerve fibers. However, we could find no evidence for a role of TRPA1 in this response, suggesting that ozone was not sensitizing airway sensory nerves via activation of this receptor. Whereas the ozone-induced hypertussive response was accompanied by a significant influx of neutrophils into the airway, the hypertussive response was not inhibited by the anti-inflammatory phosphodiesterase 4 inhibitor roflumilast at a dose that clearly exhibited anti-inflammatory activity. In summary, our results suggest that ozone-induced hypertussive responses to citric acid may provide a useful model for the investigation of novel drugs for the treatment of cough, but some important differences were noted between the two species with respect to sensitivity to bronchodilator drugs.

  8. Growth failure after recurrent fever in young guinea pigs.

    Science.gov (United States)

    Madu, S C; Faurie, A; Pettifor, J M; Laburn, H P

    2007-03-16

    Infection causes fever and suppression of appetite, a combination of effects which threatens normal growth in infected children. We have used an animal model to study the effects on growth of recurrent simulated Gram-positive bacterial infection. After weaning, 10 guinea pig pups underwent surgery under general anaesthesia for the implantation of temperature-sensitive radiotelemeters and thereafter were assigned to receive intramuscular injections of either 50 microg/kg muramyl dipeptide (MDP), or sterile saline. During a 30-day period corresponding to their rapid growth phase, the pups were given eight injections. MDP resulted in fevers of about 1.5 degrees C on each occasion, but no significant change in body temperature occurred after saline injections. Food intake was suppressed during each febrile episode such that 24-h intake was significantly lower on days of injections of MDP, compared to days between MDP injections in the same animals, and compared to that of animals injected with saline. The rate of weight gain of the MDP-injected guinea pigs was significantly lower than that of the control group and failed even to achieve a rate similar to the saline-injected group in their more adult-like growth phase. Plasma zinc concentration was significantly lower in MDP-compared to saline-injected animals sampled 8 days after the last injection. Our results show that recurrent fever during the growth phase of young guinea pigs results in irreversible growth failure, and that reduced food intake on days when the animals were febrile was at least partly responsible for this reduced rate of growth.

  9. Ozone-Induced Hypertussive Responses in Rabbits and Guinea Pigs.

    Science.gov (United States)

    Clay, Emlyn; Patacchini, Riccardo; Trevisani, Marcello; Preti, Delia; Branà, Maria Pia; Spina, Domenico; Page, Clive

    2016-04-01

    Cough remains a major unmet clinical need, and preclinical animal models are not predictive for new antitussive agents. We have investigated the mechanisms and pharmacological sensitivity of ozone-induced hypertussive responses in rabbits and guinea pigs. Ozone induced a significant increase in cough frequency and a decrease in time to first cough to inhaled citric acid in both conscious guinea pigs and rabbits. This response was inhibited by the established antitussive drugs codeine and levodropropizine. In contrast to the guinea pig, hypertussive responses in the rabbit were not inhibited by bronchodilator drugs (β2 agonists or muscarinic receptor antagonists), suggesting that the observed hypertussive state was not secondary to bronchoconstriction in this species. The ozone-induced hypertussive response in the rabbit was inhibited by chronic pretreatment with capsaicin, suggestive of a sensitization of airway sensory nerve fibers. However, we could find no evidence for a role of TRPA1 in this response, suggesting that ozone was not sensitizing airway sensory nerves via activation of this receptor. Whereas the ozone-induced hypertussive response was accompanied by a significant influx of neutrophils into the airway, the hypertussive response was not inhibited by the anti-inflammatory phosphodiesterase 4 inhibitor roflumilast at a dose that clearly exhibited anti-inflammatory activity. In summary, our results suggest that ozone-induced hypertussive responses to citric acid may provide a useful model for the investigation of novel drugs for the treatment of cough, but some important differences were noted between the two species with respect to sensitivity to bronchodilator drugs. PMID:26837703

  10. A restoration plan for the Fly River, Papua New Guinea

    OpenAIRE

    Swanson, Kathleen

    2003-01-01

    The Fly River Catchment drains about 3,300 km2 of southwester Papua New Guinea. The Fly River and its largest tributary, the Strickland river, are both subject to sediment discharges from mines in their headwaters. However, because of a naturally large sediment load, the increased loading on the Strickland and on the Lower fly below the confluence of the two rivers is not problematic. However, the discharge form the Ok Tedi mine into a tributaries of the Fly by the same name has choked po...

  11. Molecular basis of complement C3 deficiency in guinea pigs.

    OpenAIRE

    Auerbach, H S; de Burger, R; Dodds, A.; Colten, H R

    1990-01-01

    In experiments to ascertain the biochemical basis of a genetically determined deficiency of the third component of complement (C3) in guinea pigs, we found that C3-deficient liver and peritoneal macrophages contain C3 messenger RNA of normal size (approximately 5 kb) and amounts, that this mRNA programs synthesis of pro-C3 in oocytes primed with liver RNA and in primary macrophage cultures. In each instance, heterodimeric native C3 protein was secreted with normal kinetics but the C3 protein ...

  12. Conflict, Growth, and Poverty in Guinea-Bissau

    OpenAIRE

    Barry, Boubacar-Sid; Wodon, Quentin

    2007-01-01

    Conflicts and political instability have been serious constraints to growth in Guinea-Bissau. Of special concern was the civil war of 1998, which lasted 11 months and led to substantial loss of life as well as to a massive decrease in GDP per capita. Based on research on the economic cost of conflicts in Sub-Saharan Africa conducted by Lopez and Wodon (2005) and using a technique to identify outliers in time series and to correct the series for such outliers, this chapter estimates that GDP p...

  13. Formation of slow-reacting substance by guinea pig immunoglobulins.

    Science.gov (United States)

    Jancar, S.; Akimura, O. K.; Dias da Silva, W.

    1976-01-01

    The capacity of guinea pig antibodies to mediate the antigen-induced release of slow-reacting substance (SRS) in the rat peritoneal cavity is restricted to IgG2 and, to a lesser extent, to IgG1 populations of immunoglobulin. IgM and homocytotropic antibody of the reaginic type lacked this activity. The process was partially blocked by previous decomplementation of the rats, was not affected by previous reduction of the circulating leukocytes, and was partially suppressed by previous depletion of circulating platelets with an antiserum to rat platelets. PMID:11696

  14. Observations on chloralose-induced myoclonus in guinea-pigs.

    OpenAIRE

    Chadwick, D; Hallett, M.; Jenner, P; Marsden, C D

    1980-01-01

    1 The physiological, biochemical and pharmacological features of alpha-chloralose-induced myoclonus in the guinea-pig have been studied. 2 EMG bursts in muscles jerking in chloralose-induced myoclonus are long, and are not time-locked to any cortical event recorded in the EEG, although they are evoked by auditory or peripheral nerve stimuli. 3 The efferent conduction velocity down the spinal cord of the signals generating the EMG bursts is fast but the afferent conduction velocity up the cord...

  15. An Enduring Rapidly Moving Storm as a Guide to Saturn's Equatorial Jet Complex Structure

    Science.gov (United States)

    Sanchez-Lavega, A.; Wong, M. H.; Simon, A. A.; Hueso, R.; Perez-Hoyos, S.; Antuñano, A.; Rojas, J. F.; del Rio-Gaztelurrutia, T.; Barrado-Izagirre, N.; Garate-Lopez, I.; Garcia-Melendo, E.; Sanz-Requena, J. F.; Gomez-Forrelad, J. M.; De Pater, I.; Li, L.

    2015-12-01

    Saturn has an intense and broad eastward equatorial jet at cloud level whose variability and meridional and vertical structure are complex and actively debated. Due to its 27º rotation axis tilt and orbital eccentricity, Saturn is under a strong seasonal insolation cycle, enhanced at equator by the ring shadowing periods. These factors make it a good natural laboratory to test models of equatorial jet generation in giant planets. We report on a bright equatorial storm observed in 2015 that moved rapidly but steadily at a high speed of 450 ms-1, not reported since Voyagers times (Sanchez-Lavega et al., Icarus 147, 405-420, 2000). Imaging with the Hubble Space Telescope (HST) WFC3 showed detailed storm morphology at red wavelengths (689, 750 and 937 nm) confirming its high speed. Other equatorial clouds moved with velocities matching the Cassini ISS profile (García-Melendo et al., Icarus, 215, 62-74, 2011), while the storm matches the Voyager 1 and 2 profile. We interpret this result as the simultaneous detection of the wind profile at two separated altitude levels within the cloud layer. In addition, the HST methane band and ultraviolet images, allowed retrieving winds at a third altitude level of motion, in the haze layer above the cloud deck. Combining the current wind data with previous dates allowed us to construct a vertical - meridional section of the structure of Saturn's equatorial jet at cloud level. We discuss the implications of these results on the long-term stability of Saturn's equatorial jet.

  16. Equatorial gravitational lensing by accelerating and rotating black hole with NUT parameter

    Science.gov (United States)

    Sharif, M.; Iftikhar, Sehrish

    2016-01-01

    This paper is devoted to study equatorial gravitational lensing in accelerating and rotating black hole with a NUT parameter in the strong field limit. For this purpose, we first calculate null geodesic equation using the Hamilton-Jacobi separation method. We then numerically obtain deflection angle and deflection coefficients which depend on acceleration and spin parameter of the black hole. We also investigate observables in the strong field limit by taking the example of a black hole in the center of galaxy. It is concluded that acceleration parameter has a significant effect on the strong field lensing in the equatorial plane.

  17. Features of the F3 layer occurrence over the equatorial location of Trivandrum

    Science.gov (United States)

    Sreeja, V.; Ravindran, S.; Pant, T. K.

    2010-09-01

    The general features of the F3 layer occurrence over the magnetic equatorial location of Trivandrum (8.5° N; 77° E; dip lat ~0.5° N) in India during the period from 1996-2005 are presented using the ionosonde observations. The study brings out that the F3 layer occurrence over Trivandrum is weak and rare compared to the other equatorial locations. The F3 layer occurrence is relatively more pronounced during the magnetically active conditions, thus indicating the dependence of the layer formation over Trivandrum on magnetic activity. It is also observed that the percentage occurrence of the F3 layer decreases with increasing solar activity.

  18. On the magnitude of temperature decrease in the equatorial regions during the Last Glacial Maximum

    Institute of Scientific and Technical Information of China (English)

    王宁练; 姚檀栋; 施雅风; L.G.Thompson; J.Cole-Dai; P.-N.Lin; and; M.E.Davis

    1999-01-01

    Based on the data of temperature changes revealed by means of various palaeothermometric proxy indices,it is found that the magnitude of temperature decrease became large with altitude in the equatorial regions during the Last Glacial Maximum. The direct cause of this phenomenon was the change in temperature lapse rate, which was about(0.1±0.05)℃/100 m larger in the equator during the Last Glacial Maximum than at present. Moreover, the analyses show that CLIMAP possibly underestimated the sea surface temperature decrease in the equatorial regions during the Last Glacial Maximum.

  19. Concept development for the ITER equatorial port visible∕infrared wide angle viewing system.

    Science.gov (United States)

    Reichle, R; Beaumont, B; Boilson, D; Bouhamou, R; Direz, M-F; Encheva, A; Henderson, M; Huxford, R; Kazarian, F; Lamalle, Ph; Lisgo, S; Mitteau, R; Patel, K M; Pitcher, C S; Pitts, R A; Prakash, A; Raffray, R; Schunke, B; Snipes, J; Diaz, A Suarez; Udintsev, V S; Walker, C; Walsh, M

    2012-10-01

    The ITER equatorial port visible∕infrared wide angle viewing system concept is developed from the measurement requirements. The proposed solution situates 4 viewing systems in the equatorial ports 3, 9, 12, and 17 with 4 views each (looking at the upper target, the inner divertor, and tangentially left and right). This gives sufficient coverage. The spatial resolution of the divertor system is 2 times higher than the other views. For compensation of vacuum-vessel movements, an optical hinge concept is proposed. Compactness and low neutron streaming is achieved by orienting port plug doglegs horizontally. Calibration methods, risks, and R&D topics are outlined.

  20. Features of highly structured equatorial plasma irregularities deduced from CHAMP observations

    DEFF Research Database (Denmark)

    Xiong, C.; Luhr, H.; Ma, S. Y.;

    2012-01-01

    In this study five years of CHAMP (Challenging Mini-satellite Payload) fluxgate magnetometer (FGM) data is used to investigate the characteristics of Equatorial Plasma Bubbles (EPBs). We filtered the FGM data by using bandpasses with four different cut-off periods to get the EPBs with different...... maximum spatial scale sizes in the meridional plane ranging from 76-608 km. Associated with the EPB observations at about 400km, the typical altitude of CHAMP during the year 2000-2005, we also investigate the postsunset equatorial vertical plasma drift data from ROCSAT1 (Republic of China Satellite 1...

  1. Saturn's Equatorial Oscillation: Evidence of Descending Thermal Structure from Cassini Radio Occultations

    Science.gov (United States)

    Schinder, P. J.; Flasar, F. M.; Marouf, E. A.; French, R. G.; McGhee, C. A.; Kliore, A. J.; Rappaport, N. J.; Barbinis, E.; Fleischman, D.; Anabtawi, A.

    2011-01-01

    A series of near-equatorial radio occultations of Cassini by Saturn occurred in 2005 and again in 2009-2010. Comparison of the temperature-pressure profiles obtained from the two sets of occultations shows evidence of a descending pattern in the stratosphere that is similar to those associated with equatorial oscillations in Earth's middle atmosphere. This is the first time that this descent has been observed in another planetary atmosphere. If absorption of upwardly propagating waves drives the descent, the implied absorbed flux is 0.05 square meters per square second at least as large if not greater than on Earth.

  2. Global equatorial sea-surface temperatures over the last 150,000 years: An update from foraminiferal elemental analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.

    for the warmest waters. However, how the equatorial SST affects global climate, is still not clear. Long-term past seawater temperature records are required to understand the effect of temporal changes in equatorial SST on the global climate. Various techniques...

  3. Laboratory diagnosis of HIV infection in Papua New Guinea.

    Science.gov (United States)

    Babona, D V; Slama, G; Puiahi, E

    1996-09-01

    In Papua New Guinea, the laboratory diagnosis of HIV infection is based on proof of HIV antibody in the patient's serum. Under the government scheme, the testing is done in 30 laboratories, including the Papua New Guinea HIV Reference Laboratory (NRL), the Red Cross Blood Transfusion Service in Port Moresby, and 19 provincial and 9 district laboratories. An alternative testing strategy was adopted in 1993 based on a WHO recommendation, replacing the classical testing strategy (enzyme immunoassay + Western blot). The alternative testing strategy uses several EIA, rapid or simple HIV antibody assays for the detection and confirmation of the HIV antibody. This approach is faster and cheaper, with the same sensitivity and specificity as the classical testing algorithm. Except for the NRL, the Serodia Fujirebio HIV-1 gelatin particle agglutination assay is used throughout the country as the screening test. The PNG National HIV Reference Laboratory is the only laboratory authorized to perform confirmatory testing and to release positive results. Therefore, all serum samples reactive in the screening assay are sent to the NRL for confirmation by the battery of EIA, rapid or simple assays in accordance with the alternative testing strategy adopted. The paper explains the alternative testing strategy and highlights the principle of each individual test that is employed.

  4. Cortical evoked potentials recorded from the guinea pig without averaging.

    Science.gov (United States)

    Walloch, R A

    1975-01-01

    Potentials evoked by tonal pulses and recorded with a monopolar electrode on the pial surface over the auditory cortex of the guinea pig are presented. These potentials are compared with average potentials recorded in previous studies with an electrode on the dura. The potentials recorded by these two techniques have similar waveforms, peak latencies and thresholds. They appear to be generated within the same region of the cerebral cortex. As can be expected, the amplitude of the evoked potentials recorded from the pial surface is larger than that recorded from the dura. Consequently, averaging is not needed to extract the evoked potential once the dura is removed. The thresholds for the evoked cortical potential are similar to behavioral thresholds for the guinea pig at high frequencies; however, evoked potential thresholds are eleveate over behavioral thresholds at low frequencies. The removal of the dura and the direct recording of the evoked potential appears most appropriate for acute experiments. The recording of an evoked potential with dura electrodes empploying averaging procedures appears most appropriate for chronic studies.

  5. Synaptic localization of. kappa. opioid receptors in guinea pig neostriatum

    Energy Technology Data Exchange (ETDEWEB)

    Jomary, C.; Beaudet, A. (McGill Univ., Montreal, Quebec (Canada)); Gairin, J.E. (Centre National de la Recherche Scientifique, Toulouse (France))

    1992-01-15

    Distribution of {kappa} opioid receptors was examined by EM radioautography in sections of guinea pig neostriatum with the selective {sup 125}I-labeled dynorphin analog (D-Pro{sup 10})dynorphin-(1-11). Most specifically labeled binding sites were found by probability circle analysis to be associated with neuronal membrane appositions. Because of limitations in resolution of the method, the radioactive sources could not be ascribed directly to either one of the apposed plasma membranes. Nevertheless, three lines of evidence favored a predominant association of ligand with dendrites of intrinsic striatal neurons: (1) the high frequency with which labeled interfaces implicated a dendrite, (2) the enrichment of dendrodendritic interfaces, and (3) the occurrence of dendritic profiles labeled at several contact points along their plasma membranes. A small proportion of labeled sites was associated with axo-axonic interfaces, which may subserve the {kappa} opioid-induced regulation of presynaptic dopamine and acetylcholine release documented in guinea pig neostriatum. These results support the hypothesis that in mammalian brain {kappa} opioid receptors are conformationally and functionally distinct from {mu} and {delta} types.

  6. Spasmolytic effect of traditional herbal formulation on guinea pig ileum

    Directory of Open Access Journals (Sweden)

    Dushyant Kumar

    2015-01-01

    Full Text Available Background: The herbal formulation consisting of Andrographis paniculata Nees., Cassia fistula L., Foeniculum vulgare Mill. and Cuminum cyminum L. is widely used by the local traditional practitioners in rural Northern Karnataka for spasmodic abdominal pain. Objective: The present study was undertaken to evaluate safety and spasmolytic effect of poly-herbal formulation. Materials and Methods: Acute toxicity studies were carried out in Swiss mice, as per the Organization for Economic Co-operation and Development (OECD guidelines. The spasmolytic activity of the formulation was studied in isolated guinea pig ileum model using histamine and acetylcholine as agonists. The data were analyzed by one-way ANOVA, followed by Dunnetts post-hoc test and P ≤ 0.05 was considered as significant. Results: The formulation did not show any adverse toxic effects and found to be safe. It also showed significant (P < 0.05 relaxation in different agonist like histamine and acetylcholine-induced contractions in guinea pig ileum. Conclusions: Antispasmodic activity of the herbal formulation can be attributed to its atropine-like activity. The present findings, therefore, support its utility in spasmodic abdominal pain.

  7. Cutaneous sensitization to some polyisocyanate prepolymers in guinea pigs.

    Science.gov (United States)

    Zissu, D; Binet, S; Limasset, J C

    1998-11-01

    Isocyanates are used extensively in the polyurethane industry. Pulmonary and dermal sensitization resulting from exposure to diisocyanates has frequently been reported, but the potential effects of polyisocyanates on health are less well known. Thus, since 1978, occupational exposure limits have been established for diisocyanates only. Nevertheless, respiratory diseases and dermatitis have been reported in the polyurethane industry after accidental isocyanate contact during spills or splashes. The aim of this experimental work was to assess the dermal hypersensitivity of guinea pigs to some polyisocyanate prepolymers by means of a well-conducted standard predictive Buehler test. Our results showed that dicyclohexylmethane 4,4'-diisocyanate (HMDI), toluylene 2,4-diisocyanate (TDI), TDI adduct triol, TDI isocyanurate, 1,6-hexamethylene diisocyanate (HDI), HDI isocyanurate, HDI biuret and isophorone diisocyanate (IPDI) induced dermal sensitization while IPDI isocyanurate did not. In conclusion, the dermal hypersensitivity of guinea pigs to some polyisocyanates was similar to those of their corresponding monomers except for IPDI isocyanurate, suggesting that the results from diisocyanate monomers could not be a valuable approach for the detection of the sensitization potency of the corresponding prepolymers. PMID:9840262

  8. Guinea Pig Maximization Test for Trichloroethylene and Its Metabolites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objectives To study the contact allergenic activities of trichloroethylene (TCE) and its three metabolites trichloroacetic acid, trichloroethanol and chloral hydrate. Methods A modified guinea pig maximization test (GPMT) was adopted. The skin sensitization (edema and erythema) was observed in trichloroethylene, trichloroacetic acid, trichloroethanol, chloral hydrate and 2,4-dinitrochlorobenzene. Results The allergenic rate of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 71.4%, 58.3% and 100.0% respectively, and that of trichloroethanol and chloral hydrate was 0%. The mean response score of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 2.3, 1.1, 6.0 respectively. The histopathological analysis also showed an induction of allergenic transfomation in guinea pig skin by both TCE and trichloroacetic acid. Conclusion TCE appears to be a strong allergen while trichloroacetic acid a moderate one. On the other hand, both trichloroethanol and chloral hydrate are weak sensitization potentials. Immunologic reaction induced by TCE might be postulated as the pathological process of this illness. Consequently, it is suggested that in the mechanism of Occupational Dermatitis Medicamentose-Like (ODML) induced by TCE, the chemical itself might be the main cause of allergy. As one of its metabolic products, trichloroacetic acid might be a subordinate factor.

  9. Morphogenesis in guinea grass pastures under rotational grazing strategies

    Directory of Open Access Journals (Sweden)

    Denise Baptaglin Montagner

    2012-04-01

    Full Text Available This study was conducted in order to evaluate the morphogenetic and structural characteristics of guinea grass cv. Mombasa under three post-grazing heights (intense - 30 cm, lenient - 50 cm and variable - 50 in spring-summer and 30 cm in autumn-winter when sward light interception reached 95% during regrowth. Post-grazing heights were allocated to experimental units (0.25 ha in a completely randomized block design with three replications. Post-grazing heights affected only leaf elongation rate and the number of live leaves. Pastures managed with variable post-grazing height showed higher leaf elongation rate in the summer of 2007. This management strategy also resulted in a higher number of live leaves. During the spring of 2006, plants showed lower leaf elongation rate, leaf appearance rate and number of live leaves, and greater phyllochron and leaf lifespan. In contrast, during the summer of 2007, the leaf appearance rate, leaf elongation rate, number of live leaves, and final leaf length were greater while phyllochron, stem elongation rate, and leaf senescence rate were lower. The management of the guinea grass cv. Mombasa with intense or variable post-grazing height throughout the year seems to represent an interesting management target, in terms of leaf appearance rate and number of live leaves.

  10. Measurement of guinea pig eosinophil major basic protein by radioimmunoassay

    International Nuclear Information System (INIS)

    Guinea pig eosinophil major basic protein (MBP) was measured by radioimmunoassay (RIA) using 131I-MBP. Two critical features of the assay were: (1) alkylation of the MBP with iodoacetamide prior to radioiodination and (2) inclusion of another basic protein, either protamine or histone, in the phosphate buffer. Freshly isolated non-alkylated MBP was immunologically deficient when compared to alkylated or reduced MBP, but its reactivity could be redtores by reduction with dithiothreitol and alkylation. Reduction and alkylation also restored the immunoreactivity of polymerized MBP. MBP levels were not elevated in sera from guinea pigs parasitized with Trichinella spiralis and having peripheral blood eosinophilia. Muscle extracts from Trichinella infected animals showed significantly higher levels of MBP activity than normal controls. MBP was measurable in extracts of untreated eosinophils, but reduction and alkylation of these extracts increased MBP activity several fold. The RIA permits detection of MBP in body fluids and tissues at levels as low as 2 ng./ml. The RIA is useful in assessing increased or decreased levels of MBP activity in samples from experimental animals when compared to samples from controls. (author)

  11. A comparison of virulence of intraperitoneal infection of Burkholderia mallei strains in guinea-pigs

    Directory of Open Access Journals (Sweden)

    Eslampanah, M.

    2015-12-01

    Full Text Available Male guinea pigs show high susceptibility to Burkholderia mallei and have been used as animal models in glanders studies. The purpose of our study was to elucidate glanders comparative pathogenesis in guinea pigs. We present here the histological changes and bacterial isolation that develop over time in guinea pigs inoculated intraperitoneally (IP with two strain of B. mallei. Ten male guinea pigs were inoculated intraperitoneally with either the standard strain of Burkholderia mallei or B. mallei strain from Siberian tiger at the Tehran zoo individually, then euthanized at multiple time points post inoculation. Histopathologic changes were similar in both groups and consisted of pyogranulomatous inflammation. In the standard strain study guinea pigs, changes were first seen at 48 hours in liver and heart then in spleen, lung, and kidney at day 3. These changes generally reached maximal incidence and severity by day 3 but decreased by comparison in all tissues except the liver, lung and kidney. Changes were first seen in Siberian tiger strain study guinea pigs also at 48 hours in lung, liver and spleen. At day 3, changes were present in liver, spleen and mediastinal lymph nodes. These changes were maximal at day 4 and 5. In contrast there are differences in incidence and severity between the two strain study guinea pigs. Our findings based on histopathological study indicate that Siberian tiger strain has more severity in gross and necropsy examination but in pathologic lesion was qualitatively similar generally. Additionally, by bacterial isolation, we confirmed the presence of B. mallei.

  12. Guinea pig model for evaluating the potential public health risk of swine and avian influenza viruses.

    Directory of Open Access Journals (Sweden)

    Yipeng Sun

    Full Text Available BACKGROUND: The influenza viruses circulating in animals sporadically transmit to humans and pose pandemic threats. Animal models to evaluate the potential public health risk potential of these viruses are needed. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the guinea pig as a mammalian model for the study of the replication and transmission characteristics of selected swine H1N1, H1N2, H3N2 and avian H9N2 influenza viruses, compared to those of pandemic (H1N1 2009 and seasonal human H1N1, H3N2 influenza viruses. The swine and avian influenza viruses investigated were restricted to the respiratory system of guinea pigs and shed at high titers in nasal tracts without prior adaptation, similar to human strains. None of the swine and avian influenza viruses showed transmissibility among guinea pigs; in contrast, pandemic (H1N1 2009 virus transmitted from infected guinea pigs to all animals and seasonal human influenza viruses could also horizontally transmit in guinea pigs. The analysis of the receptor distribution in the guinea pig respiratory tissues by lectin histochemistry indicated that both SAα2,3-Gal and SAα2,6-Gal receptors widely presented in the nasal tract and the trachea, while SAα2,3-Gal receptor was the main receptor in the lung. CONCLUSIONS/SIGNIFICANCE: We propose that the guinea pig could serve as a useful mammalian model to evaluate the potential public health threat of swine and avian influenza viruses.

  13. Equatorial superrotation in Held & Suarez-like flows with weak equator-to-pole surface temperature gradient

    CERN Document Server

    Polichtchouk, Inna

    2016-01-01

    Equatorial superrotation under zonally-symmetric thermal forcing is investigated in a setup close to that of the classic Held & Suarez (1994) setup. In contrast to the behaviour in the classic setup, a transition to equatorial superrotation occurs when the equator-to-pole surface equilibrium entropy gradient is weakened. Two factors contribute to this transition: 1) the reduction of breaking Rossby waves from the mid-latitude that decelerate the equatorial flow and 2) the presence of barotropic instability in the equatorial region, providing stirring to accelerate the equatorial flow. In the latter, Kelvin waves excited by instability near the equator generate and maintain the superrotation. However, the superrotation is unphysically enhanced if simulations are under-resolved and/or over-dissipated.

  14. Towards global Guinea worm eradication in 2015: the experience of South Sudan.

    Science.gov (United States)

    Awofeso, Niyi

    2013-08-01

    For centuries, the Guinea worm parasite (Dracunculus medinensis) has caused disabling misery, infecting people who drink stagnant water contaminated with the worm's larvae. In 2012, there were 542 cases of Guinea worm reported globally, of which 521 (96.1%) were reported in South Sudan. Protracted civil wars, an inadequate workforce, neglect of potable water provision programs, suboptimal Guinea worm surveillance and case containment, and fragmented health systems account for many of the structural and operational factors encumbering South Sudan's Guinea worm eradication efforts. This article reviews the impacts of six established Guinea worm control strategies in South Sudan: (1) surveillance to determine actual caseload distribution and trends in response to control measures; (2) educating community members from whom worms are emerging to avoid immersing affected parts in sources of drinking water; (3) filtering potentially contaminated drinking water using cloth filters or filtered drinking straws; (4) treating potentially contaminated surface water with the copepod larvicide temephos (Abate); (5) providing safe drinking water from boreholes or hand-dug wells; and (6) containment of transmission through voluntary isolation of each patient to prevent contamination of drinking water sources, provision of first aid, and manual extraction of the worm. Surveillance, community education, potable water provision, and case containment remain weak facets of the program. Abate pesticide is not a viable option for Guinea worm control in South Sudan. In light of current case detection and containment trends, as well as capacity building efforts for Guinea worm eradication, South Sudan is more likely to eradicate Guinea worm by 2020, rather than by 2015. The author highlights areas in which substantial improvements are required in South Sudan's Guinea worm eradication program, and suggests improvement strategies. PMID:23623648

  15. Pathogenesis of a Chinese strain of bovine adenovirus type 3 infection in albino guinea pigs.

    Science.gov (United States)

    Shi, Hong-Fei; Zhu, Yuan-Mao; Yan, Hao; Ma, Lei; Wang, Xue-Zhi; Xue, Fei

    2014-12-01

    Bovine adenovirus type 3 (BAV-3) is considered one of the most important respiratory tract agents of cattle and is widespread among cattle around the world. A BAV-3 strain was isolated from a bovine nasal swab for the first time in China in 2009 and named HLJ0955. Subsequently, BAV-3 has frequently been isolated from calves with respiratory diseases in China. To date, only limited study on the pathogenesis of BAV-3 infection in cotton rats has been conducted, and the pathogenesis of BAV-3 infection in guinea pigs has not been reported. Therefore, sixteen albino guinea pigs were inoculated intranasally with HLJ0955. All of the infected guinea pigs had apparently elevated rectal temperatures (39.2 °C-39.9 °C) at 2-7 days post-inoculation (PI). Consolidation and petechial hemorrhage were also observed in guinea pigs experimentally infected with HLJ0955. Viral replication was detectable by virus isolation and titration and by immunohistochemistry in the lungs of guinea pigs as early as 24 h PI. Viral DNA was detectable in the lungs of infected guinea pigs during 11 days of observation by real-time PCR. Virus-neutralizing antibodies against BAV-3 were detectable from 11 days PI and reached a peak titer at 15 days PI. Histopathological changes mainly occurred in the lungs of infected guinea pigs and were characterized by thickening of alveolar septa, mononuclear cell infiltration, hemorrhage and alveolar epithelial necrosis. These results indicate that HLJ0955 can replicate in the lungs of guinea pigs and cause fever and gross and histological lesions. The guinea pig infection model of BAV-3 would serve as a useful system for monitoring the infection process and pathogenesis of the Chinese BAV-3 strain HLJ0955, as well as immune responses to BAV-3 vaccines.

  16. Interannual variability of the Equatorial Jets in the Indian Ocean from the merged altimetry data

    Digital Repository Service at National Institute of Oceanography (India)

    Somayajulu, Y.K.; Murty, V.S.N.; Neelima, C.; Jagadeesh, P.S.V.

    The merged ERS-1/2, TOPEX/Poseidon and Jason-1 altimeter weekly sea level anomalies (SLAs) for the period 1997- 2005 were analyzed to study the variability of sea level and computed geostrophic currents in relation to the equatorial jets...

  17. Estimation of eddy diffusivity coefficient of heat in the upper layers of equatorial Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Zavialov, P.O.; Murty, V.S.N.

    in the Central Equatorial Arabian Sea (CEAS). A comparison of the model computed K sub(h) values with those estimated from the heat balance of the upper layer (50 m) of the sea shows good agreement in the region of weak winds (CEAS) or low turbulent mixing regime...

  18. Variability in foF2 at an equatorial station and the influence of magnetic activity

    International Nuclear Information System (INIS)

    Variability in foF2 is investigated for an equatorial station in the African region. Variability during the day time at high solar activity varies between 10 and 30 percent. It varies between 10 and 20 percent at high solar activity. Magnetic storms increase the variability at both solar activity periods. (author)

  19. Plasma blobs and irregularities concurrently observed by ROCSAT-1 and Equatorial Atmosphere Radar

    Science.gov (United States)

    Yokoyama, Tatsuhiro; Su, Shin-Yi; Fukao, Shoichiro

    2007-05-01

    Plasma density enhancements, or plasma blobs, and radar backscatter plumes in the nighttime equatorial F region, both of which are intriguing phenomena associated with equatorial spread F (ESF), were concurrently observed for the first time on 8 March 2004 along a common magnetic flux tube. The observational results are strong evidence of a close relationship between plasma bubbles and blobs in the equatorial ionosphere. Plasma blobs were detected by Republic of China Scientific Satellite (ROCSAT)-1 at a dip latitude of ˜9°N, while the 47-MHz Equatorial Atmosphere Radar (EAR) in Sumatra, Indonesia, observed the backscatter plume associated with plasma density depletions, or plasma bubbles, at dip latitudes of as high as 13°S. The plumes grew upward with large Doppler velocity away from the radar late in the premidnight sector, in association with the appearance of the plasma blobs. The zonal structure and upward drift velocity of the blobs correspond to those of the plumes on the common magnetic flux tube. Localized eastward polarization electric fields probably play an important role in the generation of plasma blobs as well as the resurgence of the plumes.

  20. Short-Term Variations in the Equatorial Rotation Rate of Sunspot Groups

    CERN Document Server

    Javaraiah, J

    2016-01-01

    We have detected several periodicities in the solar equatorial rotation rate of sunspot groups in the Greenwich Photoheliographic Results (GPR) during the period 1931-1976, the Solar Optical Observing Network (SOON) during the period 1977-2014, and the Debrecen Photoheliographic Data (DPD) during the period 1974-2014. Our results suggest a ~250-day period in the equatorial rotation rate determined from both the Mt. Wilson Doppler-velocity data and the sunspot-group data during 1986-2007. However, a wavelet analysis reveals that this periodicity appears mostly around 1991 in the velocity data, while it is present in most of the solar cycles covered by the sunspot-group data, mainly near the minimum epochs of the solar cycles. We also found the signature of a period of ~1.4 years period in the velocity data during 1990-1995, and in the equatorial rotation rate of sunspot groups mostly around the year 1956. The equatorial rotation rate of sunspot groups reveals a strong ~1.6-year periodicity around 1933 and 1955...

  1. Some results of analysis of inverted echo-sounder records from the Atlantic Equatorial region

    Directory of Open Access Journals (Sweden)

    Alberto dos Santos Franco

    1985-01-01

    Full Text Available The tidal analysis of data from the Equatorial region, given by inverted echo-sounders, show considerable residuals in the frequency band of approximately 2 cycles per day. In the even harmonics of 4 and 6 cycles per day, tidal components statistically not negligible are also identified. Spectral analysis of temperature series from the same area show, on the other hand, variabilities in the same frequency bands, which suggests the occurrence of internal waves with energy distributed in these frequency bands, in the Atlantic Equatorial area.Análises de dados de maré, da zona equatorial, obtidos com ecobatímetros invertidos, mostram consideráveis resíduos na faixa de freqüências com aproximadamente dois ciclos por dia. Nos harmônicos pares com 4 e 6 ciclos por dia são também identificadas componentes de maré estatisticamente não desprezíveis. Análises espectrais de séries de temperatura obtidas na mesma área mostram, 218 por outro lado, variabilidades na mesma faixa de freqüências, o que sugere a ocorrência, na área equatorial Atlântica, de ondas internas com energia distribuída nessas faixas espectrais.

  2. Simulation of equatorial and high-latitude jets on Jupiter in a deep convection model.

    Science.gov (United States)

    Heimpel, Moritz; Aurnou, Jonathan; Wicht, Johannes

    2005-11-10

    The bands of Jupiter represent a global system of powerful winds. Broad eastward equatorial jets are flanked by smaller-scale, higher-latitude jets flowing in alternating directions. Jupiter's large thermal emission suggests that the winds are powered from within, but the zonal flow depth is limited by increasing density and electrical conductivity in the molecular hydrogen-helium atmosphere towards the centre of the planet. Two types of planetary flow models have been explored: shallow-layer models reproduce multiple high-latitude jets, but not the equatorial flow system, and deep convection models only reproduce an eastward equatorial jet with two flanking neighbours. Here we present a numerical model of three-dimensional rotating convection in a relatively thin spherical shell that generates both types of jets. The simulated flow is turbulent and quasi-two-dimensional and, as observed for the jovian jets, simulated jet widths follow Rhines' scaling theory. Our findings imply that Jupiter's latitudinal transition in jet width corresponds to a separation between the bottom-bounded flow structures in higher latitudes and the deep equatorial flows. PMID:16281029

  3. A note on new indices for the equatorial Indian Ocean oscillation

    Indian Academy of Sciences (India)

    P A Francis; Sulochana Gadgil

    2013-08-01

    It is now well known that there is a strong association of the extremes of the Indian summer monsoon rainfall (ISMR) with the El Niño and southern oscillation (ENSO) and the Equatorial Indian Ocean Oscillation (EQUINOO), later being an east–west oscillation in convection anomaly over the equatorial Indian Ocean. So far, the index used for EQUINOO is EQWIN, which is based on the surface zonal wind over the central equatorial Indian Ocean. Since the most important attribute of EQUINOO is the oscillation in convection/precipitation, we believe that the indices based on convection or precipitation would be more appropriate. Continuous and reliable data on outgoing longwave radiation (OLR), and satellite derived precipitation are now available from 1979 onwards. Hence, in this paper, we introduce new indices for EQUINOO, based on the difference in the anomaly of OLR/precipitation between eastern and western parts of the equatorial Indian Ocean. We show that the strong association of extremes of the Indian summer monsoon with ENSO and EQUINOO is also seen when the new indices are used to represent EQUINOO.

  4. Regional relationship between the Jiang-Huai Meiyu and the equatorial surface-subsurface temperature anomalies

    Institute of Scientific and Technical Information of China (English)

    QIAN WeiHong; ZHU Jiang; WANG YongGuang; FU JiaoLan

    2009-01-01

    The Jiang-Huai Meiyu rainy season can be distinguished into the Jiangnan Meiyu spell and the Huaihe Meiyu spell. The Jiangnan Meiyu spell appears on the last ten days in June and the Huaihe Meiyu spell lasts from early July to middle July. An inter-decadal transition was observed in 1998 respectively from the anomalies of Jiangnan Meiyu rainfall, the sea surface temperature (SST), and the subsurface tem-perature in the equatorial Pacific. Since the beginning of the 21 st century, opposite trends and biennial oscillations of the Meiyu rainfall are observed in the Jiangnan and Huaihe basins. Before the strong La Nina of 1999-2000, the positive SST anomalies usually occurred in the eastern equatorial Pacific. Since the beginning of the 21st century, a precursory warming signal of SST anomaly comes from the subsurface temperature which is centrally exposed near the dateline in the central equatorial Pacific. The above-normal Meiyu rainfall in 2003, 2005 and 2007 over the Huaihe basin followed the prior winter-spring positive SST anomaly near the dateline. A relationship shows that the more Jiangnan (Huaihe) Meiyu follows the winter-spring warm water in the eastern (central) equatorial Pacific.

  5. Equatorial drift paths of plasma particles in the Mead-Fairfield magnetospheric model

    International Nuclear Information System (INIS)

    Drift paths of electrons and protons with magnetic moment of 0, 0.005, 0.05 and 0.5 keV/nT in the equatorial plane are calculated for the Mead-Fairfield (MF) magnetospheric model in the superquite (SQ) and superdisturbed (SD) conditions in order to study effects of the tailward stretching geomagnetic field on drift motion of plasma particles. Uniform dawn-dusk electric fields of Ew = 0.1 mV/m and 0.4 mV/m are used to examine which of the uniform electric field or the geomagnetic field model affects more the particle motion in the equatorial plane. The calculated results indicate that the effect of tailward stretching magnetic field on the particle motion is significant in the evening and morning outer-magnetosphere. The forbidden region of zero-energy particles computed in the equatorial plane of the MF-SQ and MF-SD geomagnetic field for a uniform dawn-dusk electric field of 0.1 mV/m agrees with the average location of the equatorial plasmapause. Especially the stagnation region of zero-energy particles can explain well the plasmapause bulge observed in the late evening sector and also the local time shift of the plasmapause bulge with the geomagnetic activities by taking no account of the ionospheric conductivity. (Nogami, K.)

  6. Eastern equatorial Pacific Ocean T-S variations with El Nino

    Science.gov (United States)

    Wang, O.; Fukumori, I.; Lee, T.; Johnson, G. C.

    2004-01-01

    Temperature-Salinity (T-S) relationship variability in the pycnocline of the eastern equatorial Pacific Ocean (NINO3 region, 5 degrees S ??degrees N, 150 degrees W ?? degrees W) over the last two decades is investigated using observational data and model simulation.

  7. Dynamical theory driven observational analysis of ENSO modes in the equatorial Pacific

    Science.gov (United States)

    Weare, Bryan C.

    2016-09-01

    The dynamics of tropical Pacific sea surface height changes associated with El Niño/Southern Oscillation (ENSO) have been explored using a melding of a simple dynamical model and maximum covariance analysis (MCA). Two dominant MCA modes, which are degenerate and well correlated at a lag of about 4 months, have a combined time series which is strongly correlated with the Niño3.4 ENSO index. The leading Equatorial Mode shows a strong equatorial signature and is associated with Kelvin wave forcing, Ekman pumping, the wind stress curl, and the Recharge Oscillator hypothesis. The lagging East/West Mode shows a less equatorially trapped east/west pattern of variation and is most associated with zonal wind stress and the Delayed Oscillator hypothesis. The net effect of internal equatorial Rossby waves is dissipative and is not confined to the western boundary. The relevant zonal stress and stress curl fields stretch across the basin. Additional analyses show that both the zonal wind stress and the wind stress curl terms are required for the development of classic ENSO events. Removal of either term gives rise to weaker events, which have properties similar to the central Pacific ENSO events. The seasonal phase-locking of ENSO events is shown to be related to a north to south excursion of wind stress anomalies.

  8. Observational evidence of lower-frequency Yanai waves in the central equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    David; PrasannaKumar, S.; Byju, P.; Sarma, M.S.S.; Suryanarayana, A.; Murty, V.S.N.

    Version: J. Geophys. Res. (C: Oceans): 116(6); 2011; doi:10.1029/2010JC006603, 17 pp Observational evidence of lower frequency Yanai wave in the central equatorial Indian Ocean Divya T. David 1 , S. Prasanna Kumar *1 , P. Byju 1 , M.S.S. Sarma 1...

  9. Enhanced mixing in the equatorial thermocline induced by inertia-gravity waves

    Science.gov (United States)

    Natarov, Andrei; Richards, Kelvin

    2016-04-01

    Observations show turbulence activity is enhanced in and above the equatorial thermocline. This enhancement is brought about in part by the generation, propagation and dissipation of wind-driven inertia-gravity waves (IGWs). Numerical experiments show that in a zonally symmetric model of a tropical ocean forced by a transient wind stress both IGW activity and the energy dissipation have a pronounced maximum in the thermocline close to the equator regardless of the latitudinal distribution of the energy input into the ocean's mixed layer by the wind. We show that this equatorial enhancement is caused by a combination of three factors: a stronger superinertial component of the wind forcing close to the equator, wave action convergence at turning latitudes for various equatorially trapped waves, and nonlinear wave-wave interactions between equatorially trapped waves. Amplification of IGWs also occurs due to refraction at the top of the thermocline. We show that the latter mechanism can operate at any latitude, but is limited in its capacity to amplify the Froude number associated with propagating IGW packets and requires short (shorter than the local inertial period) energetic wind bursts to produce enhanced mixing.

  10. Observational evidence of mixed rossby gravity waves at the central equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; PrasannaKumar, S.; Mohankumar, K.; Sijikumar, S.; Sivakumar, K.U.; Mathew, T.

    Six-hourly soundings (GPS sonde) were carried out at the central equatorial Indian Ocean (80º–83ºE) during 25th September–10th October 2011 under the CINDY2011 (Cooperative Indian Ocean Experiment on Intra-seasonal variability in Year 2011) field...

  11. Tropical atmospheric response to decadal changes in the Atlantic Equatorial Mode

    Science.gov (United States)

    Losada, T.; Rodríguez-Fonseca, B.

    2016-08-01

    It has been shown that the atmospheric response to the Atlantic Equatorial Mode is non-stationary. After the 1970s, Sea Surface Temperature (SST) anomalies in the tropical Atlantic are able to alter the atmosphere in the tropical Pacific via modifications of the Walker circulation. Such changes could be related to the differences in the background state of the global SSTs before and after the 1970s, but also to changes in the interannual Equatorial Mode itself. In this work we first describe the differences in the interannual Equatorial Mode before and after the 1970s. Then we use two AGCMs to perform different sensitivity experiments changing the spatial structure of the Equatorial Mode, and we explore the differences in the atmospheric response over the tropical Pacific region to each of the SST patterns considered. It is shown that the changes in the Walker Atlantic-Pacific cell produced by the EM are stronger after the 1970s, and are reinforced by the change in the impact of the EM over the Indian Ocean and the Maritime Continent. It is also shown that, although the Atlantic-Pacific connection is established by the aforementioned changes in the Walker circulation between the two basins, the modulation of the Indian sector is crucial for a realistic simulation of such connection by climate models.

  12. Zonal winds in the equatorial upper thermosphere: Decomposing the solar flux, geomagnetic activity, and seasonal dependencies

    NARCIS (Netherlands)

    Liu, H.; Lühr, H.; Watanabe, S.; Köhler, W.; Henize, V.; Visser, P.N.A.M.

    2006-01-01

    Using 3 years (2002–2004), over 16,400 orbits of measurements from the accelerometer on board the CHAMP satellite, we have studied the climatology of the equatorial zonal wind in the upper thermosphere. Several main features are noticed. The most prominent one is that the solar flux significantly in

  13. Tomographic imagine of ionospheric structures and disturbances in the region of East-Asian equatorial anomaly

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Experiments of ionospheric tomography at low latitudes along 120°E meridian and some findings from analyses of such experimental data are presented. An improved reconstruction algorithm of computerized ionospheric tomography is proposed. In this algorithm, both differential Doppler phase and differential Doppler frequency data are jointly used and the integral phase constants are determined in the reconstruction process. Our findings indicate that the reconstructed ionospheric equatorial anomaly crests usually show a tilt in rough alignment with the local geomagnetic field, coinciding with the feature predicted by the fountain mechanism. The crest locations are found to move daily in response to changes in equatorial electrodynamics. When the crest moves from one day to the next day, the tilting angle changes so as to be still aligned with the local magnetic field. It is statistically found that an equator-ward motion of the crests is accompanied with a latitudinal broadening of the crest region. The reconstructed images also indicate that the crest location determined by the maximum electron density often does not coincide with that determined by the vertical total electron content. Besides, a deep depletion of ionospheric electron density appeared just 20 minutes after sudden commencement of a moderate magnetic storm at geomagnetic latitudes around 10°N where equatorial anomaly crests usually sit. The depleted hole extends over both the bottom and top F-region, with a steep wall on its equatorial side. The present study demonstrates that ionospheric tomographic technology is very useful and effective to the investigation of the equatorial and low-latitude ionospheric structures and dynamics.

  14. Principal components of quiet time temporal variability of equatorial and low-latitude geomagnetic fields

    Science.gov (United States)

    Bhattacharyya, Archana; Okpala, Kingsley C.

    2015-10-01

    Diurnal variations of the horizontal component of the geomagnetic field ΔH on International Quiet days of 1999-2012, measured hourly at two stations in the same longitude zone in the Northern Hemisphere, near and away from the dip equator, have been subjected to principal component analysis. This technique is also applied to the difference ΔHEEJ of ΔH at these two stations, which is attributed to the equatorial electrojet (EEJ). The first three principal components, PC1-PC3, account for 91-96% of the variances in the data. Maximum contribution to the quiet day variations in ΔH around its peak in the morning hours at both the stations, and in the EEJ, comes from the day-to-day variation of the amplitude of PC1. Patterns of day-to-day variations of PC1 amplitudes for the equatorial station and the EEJ are essentially semiannual modulated by solar EUV flux, superimposed on a longer timescale solar EUV flux-dependent trend. Contributions from PC2 and to a lesser extent from PC3 are seen to be responsible for the absence of semiannual variations in ΔH in the afternoon hours at the equatorial station. Distribution of amplitudes of PC2 and PC3 for ΔHEEJ for weak electrojet days shows seasonal features in accordance with greater occurrence of afternoon (morning) counter electrojet during June (December) solstice. During the extended solar minimum, PC3 amplitudes for ΔH at the equatorial station and for the EEJ display annual variation. Possible sources for these seasonal features in the variations of equatorial ΔH are discussed.

  15. Mechanisms controlling warm water volume interannual variations in the equatorial Pacific: diabatic versus adiabatic processes

    Energy Technology Data Exchange (ETDEWEB)

    Lengaigne, M. [CNRS, UPMC, IRD, Laboratoire d' Oceanographie Experimentation et Approches Numeriques, Paris (France); Paris Cedex 05 (France); Hausmann, U. [Imperial College, Department of Physics, London (United Kingdom); Madec, G. [CNRS, UPMC, IRD, Laboratoire d' Oceanographie Experimentation et Approches Numeriques, Paris (France); National Oceanographic Centre, Southampton (United Kingdom); Menkes, C.; Vialard, J. [CNRS, UPMC, IRD, Laboratoire d' Oceanographie Experimentation et Approches Numeriques, Paris (France); Molines, J.M. [CNRS, UJF, INP, Laboratoire Ecoulements Geophysiques et Industriels, Grenoble (France)

    2012-03-15

    Variations of the volume of warm water above the thermocline in the equatorial Pacific are a good predictor of ENSO (El Nino/Southern Oscillation) and are thought to be critical for its preconditioning and development. In this study, the Warm Water Volume (WWV) interannual variability is analysed using forced general circulation model experiments and an original method for diagnosing processes responsible for WWV variations. The meridional recharge/discharge to higher latitudes drives 60% of the ENSO-related equatorial WWV variations, while diabatic processes in the eastern equatorial Pacific account for the remaining 40%. Interior meridional transport is partially compensated by western boundary transports, especially in the southern hemisphere. Diabatic equatorial WWV formation (depletions) during La Nina (El Nino) are explained by enhanced (reduced) diathermal transport through enhanced (reduced) vertical mixing and penetrating solar forcing at the 20 C isotherm depth. The respective contribution of diabatic and adiabatic processes during build-ups/depletions strongly varies from event-to-event. The WWV build-up during neutral ENSO phases (e.g. 1980-1982) is almost entirely controlled by meridional recharge, providing a text-book example for the recharge/discharge oscillator's theory. On the other hand, diabatic processes are particularly active during the strongest La Nina events (1984, 1988, 1999), contributing to more than 70% of the WWV build-up, with heating by penetrative solar fluxes explaining as much as 30% of the total build-up due to a very shallow thermocline in the eastern Pacific. This study does not invalidate the recharge/discharge oscillator theory but rather emphasizes the importance of equatorial diabatic processes and western boundary transports in controlling WWV changes. (orig.)

  16. Radiative and Dynamical Feedbacks Over the Equatorial Cold-Tongue: Results from Seven Atmospheric GCMs

    Energy Technology Data Exchange (ETDEWEB)

    Sun, D; Zhang, T; Covey, C; Klein, S; Collins, W; Kiehl, J; Meehl, J; Held, I; Suarez, M

    2005-01-04

    The equatorial Pacific is a region with strong negative feedbacks. Yet coupled GCMs have exhibited a propensity to develop a significant SST bias in that region, suggesting an unrealistic sensitivity in the coupled models to small energy flux errors that inevitably occur in the individual model components. Could this 'hypersensitivity' exhibited in a coupled model be due to an underestimate of the strength of the negative feedbacks in this region? With this suspicion, the feedbacks in the equatorial Pacific in seven atmospheric GCMs (AGCMs) have been quantified using the interannual variations in that region and compared with the corresponding calculations from the observations. The seven AGCMs are: the NCAR CAM1, the NCAR CAM2,the NCAR CAM3, the NASA/NSIPP Atmospheric Model, the Hadley Center Model, the GFDL AM2p10, and the GFDL AM2p12. All the corresponding coupled runs of these seven AGCMs have an excessive cold-tongue in the equatorial Pacific. The net atmospheric feedback over the equatorial Pacific in the two GFDL models is found to be comparable to the observed value. All other models are found to have a weaker negative net feedback from the atmosphere--a weaker regulating effect on the underlying SST than the real atmosphere. A weaker negative feedback from the cloud albedo and a weaker negative feedback from the atmospheric transport are the two leading contributors to the weaker regulating effect from the model atmosphere. All models overestimate somewhat the positive feedback from water vapor. These results confirm the suspicion that an underestimate of negative feedbacks from the atmosphere over the equatorial Pacific region is a prevalent problem. The results also suggest, however, that a weaker regulatory effect from the atmosphere is unlikely solely responsible for the 'hypersensitivity' in all models. The need to validate the feedbacks from the ocean transport is therefore highlighted.

  17. The Project Design on Gas Turbine Generator Units in the Gas Turbine Power Plant Expansion Project in Malabor Equatorial Guinea in Europe Malabo,Equatorial Guinea in Europe%赤道几内亚马拉博欧洲角燃气电厂扩容项目燃气轮发电机组的方案设计

    Institute of Scientific and Technical Information of China (English)

    王鹏飞

    2013-01-01

    以赤道几内亚马拉博欧洲角燃气电厂扩容项目实际为例,阐述了该项目燃气轮发电机组的方案设计的内容以及PG6581B型燃气轮发电机组的主体构成.经过工程实践和一年多的试运行,已经证明本项目的方案设计是符合实际的.

  18. Fertility levels, patterns and differentials in Papua New Guinea.

    Science.gov (United States)

    Agyei, W K

    1987-01-01

    On the basis of a survey conducted between November 1979 and March 1980, new evidence is presented on changes in fertility levels, patterns, and differentials in Papua New Guinea. A single-stage systematic sample designed was used to select respondents in both rural and urban areas. 3986 females in the childbearing age group of 15-49 years and 2297 males ranging in age between 20 and 54 years were interviewed. 1066 males and 1857 females lived in rural areas and 1231 males and 2129 females resided in urban areas. Information was collected on the following: births occurring in the 12 months prior to the survey; the number of children ever born of all female respondents; a complete pregnancy history of all female respondents; and the age structure of the female respondents. The results of the estimated fertility measures for the rural and urban areas of Papua New Guinea are high by world standards: adjusted estimates of total fertility rates of between 6-7, gross reproduction rates of 2.99 and 2.76, and net reproduction rates of 2.25 and 2.08 for the urban and rural areas. Fertility was higher for rural respondents in all age groups except in the 30-34 and the 45-49 age groups where the rates were slightly higher for urban respondents. These differences in the fertility rates were substantial, particularly among respondents under 25 years old. The rural total fertility rate was 8.5% higher than the urban rate; the differences in the gross reproduction rate and the net reproduction rate were 8.3% and 8.2%, respectively. In the rural sample, respondents with primary education had a slightly lower fertility than those with no education, but the respondents with secondary and tertiary education showed marked differences than those with primary education, especially in the 20-39 year age groups. The differences among the youngest (15-19) year age group and the older (40-44) and (45-49) age groups were not large. The pattern for the urban sample was similar to the rural

  19. Effect of Chlorophyll-a Spatial Distribution on Upper Ocean Temperature in the Central and Eastern Equatorial Pacific

    Institute of Scientific and Technical Information of China (English)

    LIN Pengfei; LIU Hailong; ZHANG Xuehong

    2008-01-01

    Effect of the spatial distributions of chlorophyll-a concentration on upper ocean temperature and currents in the equatorial Pacific is investigated through a set of numerical experiments by using an ocean general circulation model. This study indicates that enhanced meridional gradient of chlorophylloa between the equator and off-equatorial regions can strengthen zonal circulation and lead to a decrease in equatorial sea surface temperature (SST). However, the circulation changes by themselves are not effective enough to affect SST in the equatorial cold tongue (CT) region. The comparison between the experiments indicates that the CT SST are more sensitive to chlorophyll-a distribution away from the equator. The off-equatorial chlorophyll-a traps more solar radiation in the mixed layer, therefore, the temperature in the thermocline decreases. The cold water can then be transported to the equator by the meridional circulation within the mixed layer. Furthermore, the relation among CT SST, the surface heat flux, and the equatorial upwelling are discussed. The study implies the simulation biases of temperature on the equator are not only related to the local ocean dynamics but also related to some deficiency in simulating off-equatorial processes.

  20. Postnatal development of substance P in the inner ear of the guinea pig.

    Science.gov (United States)

    Nowak, R; Zelck, U; Rathsack, R; Oehme, P; Scholtz, H J; Koitschev, A; Beleites, B

    1990-01-01

    Appreciable amounts of substance P (SP) were found in guinea pig cochleas. The highest values were found in the postnatal period. Data presented favor the assumption of SP acting as a neuromodulator or neurotransmitter in the inner ear. PMID:1693520

  1. Participation of breast and leg muscles in shivering thermogenesis in young turkeys and guinea fowl

    NARCIS (Netherlands)

    Dietz, Maurine W.; Mourik, Sijmen van; Tøien, Øivind; Koolmees, Peter A.; Tersteeg-Zijderveld, Monique H.G.; Heldmaier, G.

    1997-01-01

    Turkey (Meleagris gallopavo) and guinea fowl (Numida meleagris) chicks (0-27 days posthatch) were exposed to decreasing or increasing ambient temperatures. Root mean square electromyographic activity of musculus pectoralis (m. pect.) and musculus iliotibialis (m. iliot.) was recorded simultaneously

  2. Family Outbreaks of Nontyphoidal Salmonellosis following a Meal of Guinea Pigs

    Directory of Open Access Journals (Sweden)

    John B. Fournier

    2015-01-01

    Full Text Available Salmonella outbreaks have been linked to a wide variety of foods, including recent nationwide outbreaks. Guinea pig (Cavia porcellus, also known as cuy or cobayo, has long been a popular delicacy and ceremonial food in the Andean region in South America. This case report describes three family outbreaks of nontyphoidal salmonellosis, each occurring after a meal of guinea pigs. We believe this case report is the first to describe a probable association between the consumption of guinea pig meat and human salmonellosis. Physicians should be aware of the association of Salmonella and the consumption of guinea pigs, given the increasing immigration of people from the Andean region of South America and the increasing travel to this region.

  3. Chronic estrogen exposure maintains elevated levels of progesterone receptor mRNA in guinea pig hypothalamus.

    Science.gov (United States)

    Bayliss, D A; Millhorn, D E

    1991-05-01

    We performed in situ hybridization on hypothalamic sections from ovariectomized guinea pig using a cocktail of three 35S-labeled oligonucleotides complementary to mammalian progesterone receptor (PR) cDNA. PR mRNA was readily detected in hypothalamic neurons from guinea pigs pretreated with 17 beta-estradiol benzoate (E2B), but not from animals which did not receive supplemental E2B. The distribution of PR mRNA-containing cells corresponded well with previous localizations of PR in guinea pig. In contrast to earlier reports of E2B regulation of PR mRNA in rat hypothalamus, however, we found that PR mRNA remained elevated during chronic exposure to E2B (up to 10 days) in guinea pig. PMID:2072827

  4. Type I hair cell degeneration in the utricular macula of the waltzing guinea pig

    DEFF Research Database (Denmark)

    Severinsen, Stig A; Raarup, Merete Krog; Ulfendahl, Mats;

    2008-01-01

    Waltzing guinea pigs are an inbred guinea pig strain with a congenital and progressive balance and hearing disorder. A unique rod-shaped structure is found in the type I vestibular hair cells, that traverses the cell in an axial direction, extending towards the basement membrane. The present study...... estimates the total number of utricular hair cells and supporting cells in waltzing guinea pigs and age-matched control animals using the optical fractionator method. Animals were divided into four age groups (1, 7, 49 and 343 day-old). The number of type I hair cells decreased by 20% in the 343 day......-old waltzing guinea pigs compared to age-matched controls and younger animals. Two-photon confocal laser scanning microscopy using antibodies against fimbrin and betaIII-tubulin showed that the rods were exclusive to type I hair cells. There was no significant change in the length of the filament rods with age...

  5. Mordellidae (Coleoptera: Heteromera) from Papua New Guinea, with descriptions of new species

    NARCIS (Netherlands)

    Batten, R.

    1990-01-01

    New records from Papua New Guinea are given for the following species: Ophthalmoglipa australis Franciscolo, Tolidopalpus castaneicolor Ermisch, Mordellapygium elongatum Ray; the following new species are described: Paratomoxia agathae, Mordellistenoda ismayi, M. trapezoides, Glipostenoda neocastane

  6. Papular dermatitis induced in guinea pigs by the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae)

    Science.gov (United States)

    Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and ...

  7. Effect of Montelukast on bradykinin-induced contraction of isolated tracheal smooth muscle of guinea pig

    Directory of Open Access Journals (Sweden)

    A Noor

    2011-01-01

    Conclusion: It is concluded that montelukast significantly inhibits, in a dose-dependent manner, the bradykinin-induced contraction of the guinea pig tracheal smooth muscle, and alludes to an interaction between the bradykinin and leukotriene mediators.

  8. Flight intensities of rock pigeons (Columba guinea and sunflower damage

    Directory of Open Access Journals (Sweden)

    O. B. Kok

    1990-07-01

    Full Text Available Daily flight patterns of rock pigeons (Columba guinea in the Bloemfontein area are characterised by prominent peaks in early morning and late afternoon. During the middle of the day the birds usually rest in shady places of buildings situated en route to and from field crops in the immediate vicinity of the city. Sunflower is damaged mainly by rock pigeons of which the local population was estimated to be at least 6000. Investigations of bird damage to sunflower within a radius of 20 km from the city centre amounts to between 1 and 7% of the potential seed yield. The regular hunting of rock pigeons is recom­mended as a deterrent.

  9. Challenges facing HIV treatment in Guinea-Bissau

    DEFF Research Database (Denmark)

    Jespersen, Sanne; Hønge, Bo Langhoff; Oliveira, Inés;

    2014-01-01

    PROBLEM: The introduction of antiretroviral therapy (ART) for HIV infection in sub-Saharan Africa has improved the quality of life of millions of people and reduced mortality. However, substantial problems with the infrastructure for ART delivery remain. APPROACH: Clinicians and researchers...... at an HIV clinic in Guinea-Bissau identified problems with the delivery of ART by establishing a clinical database and by collaborating with international researchers. LOCAL SETTING: The Bissau HIV cohort study group was established in 2007 as a collaboration between local HIV physicians and international...... HIV researchers. Patients were recruited from the HIV clinic at the country's main hospital in the capital Bissau. RELEVANT CHANGES: Between 2005 and 2013, 5514 HIV-positive patients were treated at the clinic. Working together, local health-care workers and international researchers identified...

  10. Plant regeneration from organ culture in white Guinea Yam

    International Nuclear Information System (INIS)

    Explants from leaves, leaf segments, petioles and internodal stem of in vitro grown seedlings of white guinea yam, Dioscorea rotundata Poir, cv. 'Obiaoturugo' were cultured on defined media. NAA at concentrations of 0.5-1.0 mg/1 induced shoot regeneration from petiolar and inter-nodal stem pieces, and rooting occurred with little or no callusing from whole leaves or leaf segments. With concentration of 3.0-10.0 m/1 NAA, explants from petioles, inter-nodal stem, whole leaves and leaf segments formed callus which produced roots. These explants developed plantlets when subcultured on MS medium supplemented with 2.0 mg/1 BAP and 0.1 mg/1 NAA. (author). 11 refs, 1 tab

  11. linear accelerator simulation framework with placet and guinea-pig

    CERN Document Server

    Snuverink, Jochem; CERN. Geneva. ATS Department

    2016-01-01

    Many good tracking tools are available for simulations for linear accelerators. However, several simple tasks need to be performed repeatedly, like lattice definitions, beam setup, output storage, etc. In addition, complex simulations can become unmanageable quite easily. A high level layer would therefore be beneficial. We propose LinSim, a linear accelerator framework with the codes PLACET and GUINEA-PIG. It provides a documented well-debugged high level layer of functionality. Users only need to provide the input settings and essential code and / or use some of the many implemented imperfections and algorithms. It can be especially useful for first-time users. Currently the following accelerators are implemented: ATF2, ILC, CLIC and FACET. This note is the comprehensive manual, discusses the framework design and shows its strength in some condensed examples.

  12. Changing pattern of malaria in Bissau, Guinea Bissau

    DEFF Research Database (Denmark)

    Rodrigues, Amabelia; Schellenberg, Joanna Armstrong; Kofoed, Poul-Erik;

    2008-01-01

    OBJECTIVE: To describe the epidemiology of malaria in Guinea-Bissau, in view of the fact that more funds are available now for malaria control in the country. METHODS: From May 2003 to May 2004, surveillance for malaria was conducted among children less than 5 years of age at three health centres...... covering the study area of the Bandim Health Project (BHP) and at the outpatient clinic of the national hospital in Bissau. Cross-sectional surveys were conducted in the community in different malaria seasons. RESULTS: Malaria was overdiagnosed in both health centres and hospital. Sixty-four per cent of...... the children who presented at a health centre were clinically diagnosed with malaria, but only 13% of outpatient children who tested for malaria had malaria parasitaemia. Only 44% (963/2193) of children admitted to hospital with a diagnosis of malaria had parasitaemia. The proportion of positive cases...

  13. Mycoplasma pneumoniae induces cytotoxic activity in guinea pig bronchoalveolar cells

    International Nuclear Information System (INIS)

    Precultured guinea pig alveolar macrophages (AM) and freshly harvested alveolar cells (FHAC) activated by interaction with Mycoplasma pneumoniae were cytotoxic for xenogeneic 75selenomethionine-labeled tumor target cells. Phagocytosis of whole opsonized or nonopsonized M. pneumoniae cells was more effective in eliciting cytotoxicity than uptake of sonicated microorganisms. The addition of living mycoplasma cells to the assay system enhanced the cytotoxic effect considerably. Target cells were significantly more susceptible to the cytotoxic action of phagocytes if they were coated with mycoplasma antigen or cocultured together with M. pneumoniae. The activation of the phagocytes could be inhibited by 2-deoxy-D-glucose but not by antimicrobial substances suppressing mycoplasma protein synthesis. It was accompanied by 51Cr release without detectable signs of cell damage. The supernatants of activated cells were cytotoxic for approximately 24 h. Inhibition, release, and cytotoxic activity indicate the necessity of an intact metabolism of the effector cells and suggest a secretion of cytotoxic substances

  14. Free and Convectively Coupled Equatorial Waves Simulated by CMIP5 Climate Models

    Science.gov (United States)

    Marques, Carlos A. F.; Castanheira, José M.

    2015-04-01

    It is well known that precipitation in the equatorial belt does not occur randomly, but is often organized into synoptic to planetary-scale disturbances with time scales smaller than a season. Several studies have shown that a large fraction of the convection variability in such disturbances is associated with dynamical Equatorial Waves, such as the Kelvin, Equatorial Rossby, Mixed Rossby-Gravity, Eastward and Westward Inertio-Gravity waves (e.g. Kiladis et al., Rev. Geophys., 2009). The horizontal structures and dispersion characteristics of such Convectively Coupled Equatorial Waves (CCEWs) correspond to the solutions of the shallow water (SW) equations on an equatorial β-plane obtained by Matsuno (J. Meteor. Soc. Japan, 1966). CCEWs have broad impacts within the tropics, but their simulation in general circulation models is still problematic. Using space-time spectral analyses of a proxy field for tropical convection (e.g. outgoing long wave radiation (OLR)), it has been shown the existence of spectral peaks aligned along the dispersion curves of equatorially trapped wave modes of SW theory, which have been interpreted as the effect of equatorial wave processes (e.g. Takayabu, J. Meteor. Soc. Japan, 1994; Wheeler and Kiladis, JAS, 1999). However, different equatorial modes may not be well separated in the wavenumber-frequency domain due to a vertical variation of the horizontal basic flow, that may introduce Doppler shiftings and changes in the vertical heating profiles which may distort the theoretical dispersion curves (Yang et al., JAS, 2003). In this communication, we present a new methodology for the diagnosis of CCEWs, which is based on a pre-filtering of the geopotential and horizontal wind, via three-dimensional (3-D) normal mode functions of the adiabatic linearized equations of a resting atmosphere, followed by a space-time power and cross spectral analysis applied to the 3-D normal mode filtered fields and the OLR (or other fields that may be proxies

  15. Growth and breast-milk intake in Papua New Guinea

    International Nuclear Information System (INIS)

    The purpose of this work is to show what is possible if lactation performance and growth are measured in the context of the WHO Growth Reference Study. The fact is that a piece of work very similar to that which could be reasonably proposed for the present study was done in the 1980's in Papua New Guinea (PNG) and reading Alison Orr-Ewing's thesis it is interesting to find the statement 'The apparent adequacy of mean nutrient intakes up to 6 months and the small and late effect of morbidity on weight gain observed in this study, both substantiate the suggestion that the growth faltering relative to international standards which occurs from 3-5 months is probably largely due to the inappropriate nature of the standards'. This sort of finding was emerging from many research centres at that time (see for example Whitehead and Paul, in my own department) and provided the impetus to develop new standards for growth such as in the WHO Growth Reference Programme. At the same sort of time too, both myself and Dr Peter Heywood, then at the Papua New Guinea Institute of Medical Research were attending one of the first meetings for nutritionists held at IAEA in Vienna. There is thus a certain satisfaction that can be derived from the appropriateness of describing the work at this meeting but it must be tinged with regret that it has taken nearly 20 years to achieve it. The published work from PNG deals only with lactation but the present report will contain some unpublished material on growth and morbidity

  16. Passive protection by polyclonal antibodies against Bacillus anthracis infection in guinea pigs.

    OpenAIRE

    Little, S F; Ivins, B E; Fellows, P F; Friedlander, A M

    1997-01-01

    The protective effects of polyclonal antisera produced by injecting guinea pigs with protective antigen (PA), the chemical anthrax vaccine AVA, or Sterne spore vaccine, as well as those of toxin-neutralizing monoclonal antibodies (MAbs) produced against PA, lethal factor, and edema factor, were examined in animals infected with Bacillus anthracis spores. Only the anti-PA polyclonal serum significantly protected the guinea pigs from death, with 67% of infected animals surviving. Although none ...

  17. Hereditary susceptibility to inner ear stress agents studied in heterozygotes of the German waltzing guinea pig

    OpenAIRE

    Skjönsberg, Åsa

    2006-01-01

    The German waltzing guinea pig is a strain of animals expressing deafness and severe balance disorders already at birth. The mutation arose spontaneously in a breeding facility in Germany and as the affected animals show a characteristic waltzing behavior, the strain is named the German waltzing guinea pig. The strain is presently bred only at Karolinska Institutet. The hereditary inner car impairment has a recessive mode of inheritance and the strain thus produces not o...

  18. Progress towards the eradication of Tsetse from the Loos islands, Guinea

    OpenAIRE

    Onikoyamou Mory F; Courtin Fabrice; Bouyer Jérémy; Camara Mamadou; Kagbadouno Moise S; Schofield Chris J; Solano Philippe

    2011-01-01

    Abstract Background The tsetse fly Glossina palpalis gambiensis is the main vector of sleeping sickness (Human African Trypanosomiasis - HAT) in West Africa, in particular in littoral Guinea where this disease is currently very active. The Loos islands constitute a small archipelago some 5 km from mainland Guinea, where G. p. gambiensis is well known as a nuisance and potential disease vector by inhabitants of the three main islands, Fotoba, Room, and Kassa. The National Control Program again...

  19. Molecular Phylogeny of Burkholderia pseudomallei from a Remote Region of Papua New Guinea

    OpenAIRE

    Anthony Baker; Talima Pearson; Price, Erin P.; Julia Dale; Paul Keim; Heidie Hornstra; Andrew Greenhill; Gabriel Padilla; Jeffrey Warner

    2011-01-01

    BACKGROUND: The island of New Guinea is located midway between the world's two major melioidosis endemic regions of Australia and Southeast Asia. Previous studies in Papua New Guinea have demonstrated autochthonous melioidosis in Balimo, Western province. In contrast to other regions of endemicity, isolates recovered from both environmental and clinical sources demonstrate narrow genetic diversity over large spatial and temporal scales. METHODOLOGY/PRINCIPAL FINDINGS: We employed molecular ty...

  20. Emergence of the Gulf of Guinea in the Global Economy; Prospects and Challenges

    OpenAIRE

    Damian Ondo Mañe

    2005-01-01

    The Gulf of Guinea's tremendous potential is creating investment opportunities for the region. Some of its resources, such as oil, minerals, and forests, continue to attract significant investments whereas others, like natural gas, could be exploited to their full potential if necessary investments were undertaken. Nevertheless, the Gulf of Guinea has to cope with numerous challenges, both exogenous and endogenous, before it can fully benefit from its riches. One of these problems stems from ...

  1. Assessment of vaccine testing at three laboratories using the guinea pig model of tuberculosis

    OpenAIRE

    Grover, Ajay; Troudt, JoLynn; Arnett, Kimberly; Izzo, Linda; Lucas, Megan; Strain, Katie; McFarland, Christine; Hall, Yper; McMurray, David; Williams, Ann; Dobos, Karen; Izzo, Angelo

    2011-01-01

    The guinea pig model of tuberculosis is used extensively in different locations to assess the efficacy of novel tuberculosis vaccines during pre-clinical development. Two key assays are used to measure protection against virulent challenge: a 30 day post-infection assessment of mycobacterial burden and long term post-infection survival and pathology analysis. To determine the consistency and robustness of the guinea pig model for testing vaccines, a comparative assessment between three sites ...

  2. Cumulative irritancy in the guinea pig from low grade irritant vehicles and the angry skin syndrome

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Maibach, H I

    1980-01-01

    A 4-week open cumulative irritancy test in guinea pigs discriminated between two low grade irritant vehicles, nonionic base (anhydrous) and hydrophilic ointment. The procedure might be useful as a predictive test for low grade irritants. The angry skin syndrome was established in the guinea pigs ...... one Freunds complete adjuvant intradermal injection on day 0, or by daily open applications of 10% sodium lauryl sulfate in petrolatum to the neck area of the animals....

  3. Spatial and temporal variability in nutrients and carbon uptake during 2004 and 2005 in the eastern equatorial Pacific Ocean

    DEFF Research Database (Denmark)

    Palacz, A. P.; Chai, F.

    2012-01-01

    The Eastern Equatorial Pacific plays a great role in the global carbon budget due to its enhanced biological productivity linked to the equatorial upwelling. However, as confirmed by the Equatorial Biocomplexity cruises in 2004 and 2005, nutrient upwelling supply varies strongly, also due......-temporal variability in primary productivity. We demonstrate for the first time that Tropical Instability Waves can be directly linked to increased NO3 and Si(OH)4 upwelling supply and enhanced nutrient and carbon uptake, in particular by large phytoplankton such as diatoms. In order to fully...

  4. Relationship between equatorial pressure oscillations and tropical cyclones landing over China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With daily reanalysis data by NCEP/NCAR and data of tropical cyclones landing over China from 1949 to 2005, the variation of low-frequency oscillations of equatorial pressure and their relationship with tropical cyclones landing over China in the summer half of the years (June through October) are studied for the 57 years, using spectral analysis and correlation analysis. The results show that the summertime equatorial pressure is mainly of periodic oscillations of 5―7 days and 10―30 days and the interannual variation of the intensity of its quasi-biweekly oscillation is significantly positive correlation with the number of tropical cyclones landing over China. The quasi-biweekly oscillation is filtered from daily equatorial pressure in May―November over the 57 years with inverse wavelet transform and the probability for tropical cyclones landing on coastal China within four days before and after the oscillatory valleys of quasi-biweekly pressure at the equator is 59.7% and 73.0% for June to October and July to September respectively. The model of atmospheric circulation for quasi-biweekly oscillatory valleys of equatorial pressure in association with or without tropical cyclones landing over China in July―September is set up with the composite analysis method. When the valleys are associated with (without) landfall, zonal (meridional) circulation prevails in the mid and high latitudes of the Eastern Hemisphere, the high pressure ridge is weak (strong) near the Sea of Okhotsk, the westerly zone is northward (southward), the subtropical high is westward (eastward) in location and strong (weak) in intensity, the cross-equatorial flow is strong (weak) in southeast Asia, Southwest Monsoon is strong (weak) and stronger (weaker) while in the valleys of pressure, being favorable (unfavorable) for tropical cyclones landing over China. The atmospheric circulation model for oscillatory valleys of biweekly equatorial pressure in association with (without) tropical

  5. Relationship between equatorial pressure oscillations and tropical cyclones landing over China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With daily reanalysis data by NCEP/NCAR and data of tropical cyclones landing over China from 1949 to 2005, the variation of low-frequency oscillations of equatorial pressure and their relationship with tropical cyclones landing over China in the summer half of the years (June through October) are stu- died for the 57 years, using spectral analysis and correlation analysis. The results show that the summertime equatorial pressure is mainly of periodic oscillations of 5-7 days and 10-30 days and the interannual variation of the intensity of its quasi-biweekly oscillation is significantly positive correlation with the number of tropical cyclones landing over China. The quasi-biweekly oscillation is filtered from daily equatorial pressure in May-November over the 57 years with inverse wavelet transform and the probability for tropical cyclones landing on coastal China within four days before and after the oscillatory valleys of quasi-biweekly pressure at the equator is 59.7% and 73.0% for June to October and July to September respectively. The model of atmospheric circulation for quasi-biweekly oscillatory valleys of equatorial pressure in association with or without tropical cyclones landing over China in July-September is set up with the composite analysis method. When the valleys are associated with (without) landfall, zonal (meridional) circulation prevails in the mid and high latitudes of the Eastern Hemisphere, the high pressure ridge is weak (strong) near the Sea of Okhotsk, the westerly zone is northward (southward), the subtropical high is westward (eastward) in location and strong (weak) in intensity, the cross-equatorial flow is strong (weak) in southeast Asia, Southwest Monsoon is strong (weak) and stronger (weaker) while in the valleys of pressure, being favorable (unfavorable) for tropical cyclones landing over China. The atmospheric circulation model for oscillatory valleys of biweekly equatorial pressure in association with (without) tropical cyclones

  6. Thermal Structure of Jupiter's Infrared Hotspots and Plumes in the Northern Equatorial Region

    Science.gov (United States)

    Fletcher, Leigh N.; Orton, Glenn S.; Rogers, John H.; Greathouse, Thomas K.; Momary, Thomas W.; Giles, Rohini Sara; Melin, Henrik; Sinclair, James; Irwin, Patrick Gerard Joseph; Vedovato, Marco

    2016-10-01

    The most prominent features of Jupiter's northern equatorial region are the visibly dark, 5-µm-bright 'hotspots' that move rapidly eastward on the southern edge of the North Equatorial Belt (NEB, Allison 1990, doi:10.1016/0019-1035(90)90069-L). We combine high-resolution thermal-infrared (5-20 µm) imaging from VLT/VISIR and IRTF/SpeX with spatially resolved spectroscopy from IRTF/TEXES to examine the thermal and chemical conditions in the equatorial region during the 2015-2016 apparition. The high spatial resolution permits the first detailed cross-comparison of thermal and visible-albedo conditions within the hotspots. We find that: (i) cloud-clearing within the hotspots creates 8.6-µm bright patches that are broader and more diffuse than their 5-µm counterparts; (ii) cloudy, cool cells ("plumes") in the northern Equatorial Zone are ammonia-rich and dark in the 5- and 8-12 µm range; (iii) the hotspots sometimes demonstrate a westward tilt with altitude in the 0.1-0.8 bar region (Fletcher et al., 2016, doi:10.1016/j.icarus.2016.06.008); and (iv) blue-grey streaks on the southeastern edges of these ammonia-rich cells are also cloud free and bright at 5-12 µm. This regular longitudinal pattern of cloudy cells and cloud-free hotspots is consistent with condensation of NH3-rich air as it ascends in cells, and subsidence of dry, volatile-depleted air in the hotspots. The westward tilt of the NEB hotspots with height that was detected in 2014 (but not in 2016) supports the equatorial Rossby-wave hypothesis for the NEB pattern. This equatorial wave is distinct from those in the upper troposphere during the 2015-16 NEB expansion event (Orton et al., DPS/EPSC 2016). The cells and hotspots observed in the thermal-IR are the same type as those detected at near-IR wavelengths by Galileo/NIMS (Baines et al. 2002, doi:10.1006/icar.2002.6901) and in the radio, probing the deep atmosphere (de Pater et al., 2016, doi:10.1126/science.aaf2210), suggesting a coherent structure

  7. Paleoceanographic interpretations of late Pleistocene to Holocene sedimentological and geochemical proxy-data from SE-Atlantic abyssal plains (Cape, Angola and Guinea Basin)

    Science.gov (United States)

    Piller, W. E.; Müllegger, S.

    2009-04-01

    Sediments of the deep abyssal regions of the Southeast Atlantic (Cape Basin, Angola Basin and Guinea Basin) were studied to reconstruct changes in surface and deep water circulation, bioproductivity, and terrigenous sediment flux. To gain these results various sedimentological and geochemical proxies were imposed, including grain size data, foraminiferal fragmentation, carbonate and organic carbon content, as well as stable oxygen and carbon isotope contents of foraminiferal tests. Samples were gained with a multicorer device during Meteor cruise 63/2 (2005) in water depths between ~5,100 and ~5,600 m. The superficial 30 cm of sediment, sampled in 1/2, 1 and 5 cm steps, were processed for this study. The record covers parts of the Pleistocene and Holocene. Even if the sedimentation conditions seem to be similar in the deep-sea regions of the SE-Atlantic there are clear differences between the three sampled locations. This is caused by major changes in deep water corrosiveness leading to fluctuations in the sedimentation rate and carbonate preservation. Cape Basin localities show a pattern of enhanced carbonate preservation around 12 ka BP possibly indicating a delayed Last Glacial Maximum signal. This pattern, which is typical for Indo-Pacific records, clearly points to an influence of Antarctic Bottom Water (AABW) at water depths below 5000 m in the Northern Cape Basin. The non-correlation between carbonate content and grain size distribution is owing to a coccoliths' dominated carbonate production possibly caused by low nutrient availability in surface waters and the higher dissolution susceptibility of foraminiferal tests. Angola Basin samples delivered highest sand contents, a carbonate peak and low organic carbon values around 8.2 ka BP which indicate a reduced bioproduction and nutrient supply in superficial waters. A connection of the 8.2 ka cold event in the northern hemisphere and central African precipitation, equatorial East Atlantic (EEA) upwelling

  8. Actions and mechanisms of action of novel analogues of sotalol on guinea-pig and rabbit ventricular cells.

    OpenAIRE

    Connors, S. P.; Gill, E. W.; Terrar, D. A.

    1992-01-01

    1. The actions and mechanisms of action of novel analogues of sotalol which prolong cardiac action potentials were investigated in guinea-pig and rabbit isolated ventricular cells. 2. In guinea-pig and rabbit cells the compounds significantly prolonged action potential duration at 20% and 90% repolarization levels without affecting resting membrane potential. In guinea-pig but not rabbit cells there was an increase in action potential amplitude and in rabbit cells there was no change in the s...

  9. Isolation and characterisation of a dinucleotide microsatellite set for a parentage and biodiversity study in domestic guinea pig (Cavia porcellus)

    OpenAIRE

    Diana Aviles; Vincenzo Landi; Juan Vicente Delgado; José Luis Vega-Pla; Amparo Martinez

    2015-01-01

    The domestic guinea pig is a valuable genetic resource because it is part of local folklore and food tradition in many South American countries. The economic importance of the guinea pig is due to its high feed efficiency and the quality of animal protein produced. For these reasons, our study is aimed to design a complete dinucleotide microsatellite marker set following international recommendation to assess the genetic diversity and genealogy management of guinea pigs. We selected a total o...

  10. Kinetic theory of equilibrium axisymmetric collisionless plasmas in off-equatorial tori around compact objects

    CERN Document Server

    Cremaschini, Claudio; Slaný, Petr; Stuchlík, Zdeněk; Karas, Vladimír

    2013-01-01

    The possible occurrence of equilibrium off-equatorial tori in the gravitational and electromagnetic fields of astrophysical compact objects has been recently proved based on non-ideal MHD theory. These stationary structures can represent plausible candidates for the modelling of coronal plasmas expected to arise in association with accretion discs. However, accretion disc coronae are formed by a highly diluted environment, and so the fluid description may be inappropriate. The question is posed of whether similar off-equatorial solutions can be determined also in the case of collisionless plasmas for which treatment based on kinetic theory, rather than fluid one, is demanded. In this paper the issue is addressed in the framework of the Vlasov-Maxwell description for non-relativistic multi-species axisymmetric plasmas subject to an external dominant spherical gravitational and dipolar magnetic field. Equilibrium configurations are investigated and explicit solutions for the species kinetic distribution functio...

  11. The persistence of equatorial spread F - an analysis on seasonal, solar activity and geomagnetic activity aspects

    Science.gov (United States)

    Sreeja, V.; Devasia, C. V.; Ravindran, Sudha; Sridharan, R.

    2009-02-01

    The persistence (duration) of Equatorial Spread F (ESF), which has significant impact on communication systems, is addressed. Its behavior during different seasons and geomagnetic activity levels under the solar maximum (2001) and minimum (2006) conditions, is reported using the data from the magnetic equatorial location of Trivandrum (8.5° N; 77° E; dip 0.5° N) in India. The study reveals that the persistence of the irregularities can be estimated to a reasonable extent by knowing the post sunset F region vertical drift velocity (Vz) and the magnetic activity index Kp. Any sort of advance information on the possible persistence of the ionospheric irregularities responsible for ESF is important for understanding the scintillation morphology, and the results which form the first step in this direction are presented and discussed.

  12. Electrodynamics of the equatorial F-region ionosphere during pre-sunrise period

    Science.gov (United States)

    Prabhakaran Nayar, S. R.; Mathew, T. J.; Sreehari, C. V.; Sumod, S. G.; Devasia, C. V.; Ravindran, S.; Sreeja, V.; Pant, T. Kumar; Sridharan, R.

    2009-01-01

    The electrodynamics of the pre-sunrise equatorial F-region is investigated using HF Doppler radar and digital ionosonde. The observations are limited to those days for which the radar probing frequency is below the foF2 value. The ionosphere observation using HF Doppler radar exhibit interesting features during pre-sunrise period similar to the post sunset pre-reversal enhancement. The most striking feature observed during pre-sunrise period is the sudden downward excursion in the vertical drift around local sunrise followed by an upward turning. Pre-sunrise observations of vertical plasma drift and the sunrise downward excursion followed by an upward turning after the ground sunrise related to the zonal electric field at the equatorial F-region are the most significant results not reported earlier.

  13. Features of the F3 layer occurrence over the equatorial location of Trivandrum

    Directory of Open Access Journals (Sweden)

    T. K. Pant

    2010-09-01

    Full Text Available The general features of the F3 layer occurrence over the magnetic equatorial location of Trivandrum (8.5° N; 77° E; dip lat ~0.5° N in India during the period from 1996–2005 are presented using the ionosonde observations. The study brings out that the F3 layer occurrence over Trivandrum is weak and rare compared to the other equatorial locations. The F3 layer occurrence is relatively more pronounced during the magnetically active conditions, thus indicating the dependence of the layer formation over Trivandrum on magnetic activity. It is also observed that the percentage occurrence of the F3 layer decreases with increasing solar activity.

  14. The role of Equatorial Undercurrent in sustaining the Eastern Indian Ocean upwelling

    Science.gov (United States)

    Chen, Gengxin; Han, Weiqing; Shu, Yeqiang; Li, Yuanlong; Wang, Dongxiao; Xie, Qiang

    2016-06-01

    By combining volume transport and salinity analysis from 1958 to 2014, this paper investigates how the transient Equatorial Undercurrent (EUC) sustains the summer-fall equatorial eastern Indian Ocean (EIO) upwelling. On seasonal time scales, the EIO upwelling is mainly supplied by the salty water from the western basin through a buffering process: The winter-spring EUC carries the salty water from the western basin eastward, induces downwelling in the EIO, and pushes portion of the salty water below the central thermocline, which subsequently upwells to the central thermocline during summer-fall and sustains the EIO upwelling. On interannual time scales, enhanced upwelling occurs during positive Indian Ocean Dipole (+IOD) years. The strong summer-fall EUC associated with the +IOD supplies water for the intensified upwelling. This research provides new knowledge for basin-scale mass and property exchanges associated with the EIO upwelling, contributing to our understanding of three-dimensional ocean circulation and climate variability.

  15. C/NOFS Observations of AC Electric Field Fields Associated with Equatorial Spread-F

    Science.gov (United States)

    Pfaff, R.; Liebrecht, C.

    2009-01-01

    The Vector Electric Field Investigation (VEFI) on the C/NOFS equatorial satellite provides a unique data set in which to acquire detailed knowledge of irregularities associated with the equatorial ionosphere and in particular with spread-F depletions. We present vector AC electric field observations, primarily gathered within the ELF band (1 Hz to 250 Hz) on C/NOFS that address a variety of key questions regarding how plasma irregularities, from meter to kilometer scales, are created and evolve. The data will be used to explore the anisotropy/isotropy of the waves, their wavelength and phase velocity, as well as their spectral distributions. When analyzed in conjunction with the driving DC electric fields and detailed plasma number density measurements, the combined data reveal important information concerning the instability mechanisms themselves. We also present high resolution, vector measurements of intense lower hybrid waves that have been detected on numerous occasions by the VEFI burst memory VLF electric field channels.

  16. Electrodynamics of the equatorial F-region ionosphere during pre-sunrise period

    Directory of Open Access Journals (Sweden)

    S. R. Prabhakaran Nayar

    2009-01-01

    Full Text Available The electrodynamics of the pre-sunrise equatorial F-region is investigated using HF Doppler radar and digital ionosonde. The observations are limited to those days for which the radar probing frequency is below the foF2 value. The ionosphere observation using HF Doppler radar exhibit interesting features during pre-sunrise period similar to the post sunset pre-reversal enhancement. The most striking feature observed during pre-sunrise period is the sudden downward excursion in the vertical drift around local sunrise followed by an upward turning. Pre-sunrise observations of vertical plasma drift and the sunrise downward excursion followed by an upward turning after the ground sunrise related to the zonal electric field at the equatorial F-region are the most significant results not reported earlier.

  17. Deep-reaching thermocline mixing in the equatorial pacific cold tongue

    Science.gov (United States)

    Liu, Chuanyu; Köhl, Armin; Liu, Zhiyu; Wang, Fan; Stammer, Detlef

    2016-05-01

    Vertical mixing is an important factor in determining the temperature, sharpness and depth of the equatorial Pacific thermocline, which are critical to the development of El Ninõ and Southern Oscillation (ENSO). Yet, properties, dynamical causes and large-scale impacts of vertical mixing in the thermocline are much less understood than that nearer the surface. Here, based on Argo float and the Tropical Ocean and Atmosphere (TAO) mooring measurements, we identify a large number of thermocline mixing events occurring down to the lower half of the thermocline and the lower flank of the Equatorial Undercurrent (EUC), in particular in summer to winter. The deep-reaching mixing events occur more often and much deeper during periods with tropical instability waves (TIWs) than those without and under La Niña than under El Niño conditions. We demonstrate that the mixing events are caused by lower Richardson numbers resulting from shear of both TIWs and the EUC.

  18. Detecting cross-equatorial wind change as a fingerprint of climate response to anthropogenic aerosol forcing

    Science.gov (United States)

    Wang, Hai; Xie, Shang-Ping; Tokinaga, Hiroki; Liu, Qinyu; Kosaka, Yu

    2016-04-01

    Anthropogenic aerosols are a major driver of the twetieth century climate change. In climate models, the aerosol forcing, larger in the Northern than Southern Hemispheres, induces an interhemispheric Hadley circulation. In support of the model result, we detected a robust change in the zonal mean cross-equatorial wind over the past 60 years from ship observations and reanalyses, accompanied by physically consistent changes in atmospheric pressure and marine cloud cover. Single-forcing experiments indicate that the observed change in cross-equatorial wind is a fingerprint of aerosol forcing. This zonal mean mode follows the evolution of global aerosol forcing that is distinct from regional changes in the Atlantic sector. Atmospheric simulations successfully reproduce this interhemispheric mode, indicating the importance of sea surface temperature mediation in response to anthropogenic aerosol forcing. As societies awaken to reduce aerosol emissions, a phase reversal of this interhemispheric mode is expected in the 21st century.

  19. Tomographic imagine of ionospheric structures and disturbances in the region of East-Asian equatorial anomaly

    Institute of Scientific and Technical Information of China (English)

    徐继生; 吴雄斌; 马淑英; 田茂; 俞胜兵; K.C.Yeh; J.S.Franke; W.H.Tsaoi; K.H.Lin

    2000-01-01

    Experiments of ionospheric tomography at low latitudes along 120°E meridian and some findings from analyses of such experimental data are presented. An improved reconstruction algorithm of computerized ionospheric tomography is proposed. In this algorithm, both differential Doppler phase and differential Doppler frequency data are jointly used and the integral phase constants are determined in the reconstruction process. Our findings indicate that the reconstructed ionospheric equatorial anomaly crests usually show a tilt in rough alignment with the local geomagnetic field, coinciding with the feature predicted by the fountain mechanism. The crest locations are found to move daily in response to changes in equatorial electrodynamics. When the crest moves from one day to the next day, the tilting angle changes so as to be still aligned with the local magnetic field. It is statistically found that an equator-ward motion of the crests is accompanied with a latitudinal broadening of the crest region. The r

  20. Equatorial ionosphere semiannual oscillation investigated from Schumann resonance measurements on board the C/NOFS satellite

    Science.gov (United States)

    Simões, Fernando; Pfaff, Robert; Freudenreich, Henry; Klenzing, Jeffrey; Rowland, Douglas; Bromund, Kenneth; Kepko, Larry; Le, Guan; Liebrecht, Maria Carmen; Martin, Steven; Uribe, Paulo

    2013-11-01

    of Schumann resonance signatures in the equatorial ionosphere offers remote sensing capabilities for the investigation of tropospheric and space weather effects in the ionosphere. Schumann resonances are electromagnetic oscillations in the earth-ionosphere cavity produced by lightning activity. Analysis of AC electric field measurements gathered by the Communications/Navigation Outage Forecasting System satellite reveals a semiannual pattern in Schumann resonance data recorded during nighttime in the equatorial ionosphere. This pattern observed in the Schumann resonance amplitude is expected to help validate—or at least constrain—potential mechanisms proposed to explain the semiannual oscillation observed in different geophysical records, such as those reported in a variety of tropospheric, ionospheric/thermospheric, and magnetospheric observations.

  1. Determinants of vitamin a deficiency in children between 6 months and 2 years of age in Guinea-Bissau

    DEFF Research Database (Denmark)

    Danneskiold-Samsøe, Niels; Fisker, Ane Bærent; Jørgensen, Mathias Jul;

    2013-01-01

    The World Health Organization (WHO) classifies Guinea-Bissau as having severe vitamin A deficiency (VAD). To date, no national survey has been conducted. We assessed vitamin A status among children in rural Guinea-Bissau to assess status and identify risk factors for VAD.......The World Health Organization (WHO) classifies Guinea-Bissau as having severe vitamin A deficiency (VAD). To date, no national survey has been conducted. We assessed vitamin A status among children in rural Guinea-Bissau to assess status and identify risk factors for VAD....

  2. A comparative analysis of the intestinal metagenomes present in guinea pigs (Cavia porcellus) and humans (Homo sapiens)

    DEFF Research Database (Denmark)

    Hildebrand, Falk; Ebersbach, Tine; Nielsen, Henrik Bjørn;

    2012-01-01

    Background: Guinea pig (Cavia porcellus) is an important model for human intestinal research. We have characterized the faecal microbiota of 60 guinea pigs using Illumina shotgun metagenomics, and used this data to compile a gene catalogue of its prevalent microbiota. Subsequently, we compared...... the guinea pig microbiome to existing human gut metagenome data from the MetaHIT project. Results: We found that the bacterial richness obtained for human samples was lower than for guinea pig samples. The intestinal microbiotas of both species were dominated by the two phyla Bacteroidetes and Firmicutes...

  3. Seismotectonics of New Guinea: a Model for Arc Reversal Following Arc-Continent Collision

    Science.gov (United States)

    Cooper, Patricia; Taylor, Brian

    1987-02-01

    The structure and evolution of the northern New Guinea collision zone is deduced from International Seismological Center (ISC) seismicity (1964-1985), new and previously published focal mechanisms and a reexamination of pertinent geological data. A tectonic model for the New Guinea margin is derived which illustrates the sequential stages in the collision and suturing of the Bewani-Toricelli-Adelbert-Finisterre-Huon-New Britain arc to central New Guinea followed by subduction polarity reversal in the west. East of 149°E, the Solomon plate is being subducted both to the north and south; bringing the New Britain and Trobriand forearcs toward collision. West of 149°E the forearcs have collided, and together they override a fold in the doubly subducted Solomon plate lithosphere, which has an axis that is parallel to the strike of the Ramu-Markham suture and that plunges westward at an angle of 5° beneath the coast ranges of northern New Guinea. Active volcanism off the north coast of New Guinea is related to subduction of the Solomon plate beneath the Bismarck plate. Active volcanism of the Papuan peninsula and Quaternary volcanism of the New Guinea highlands are related to slow subduction of the Solomon plate beneath the Indo-Australian plate along the Trobriand Trough and the trough's former extension to the west, respectively. From 144°-148°E, seismicity and focal mechanisms reveal that convergence between the sutured Bismarck and Indo-Australian plates is accommodated by thrusting within the Finisterre and Adelbert ranges and compression of the New Guinea orogenic belt, together with basement-involved foreland folding and thrusting to the south. The Finisterre block overthrusts the New Guinea orogenic belt, whereas the Adelbert block is sutured to New Guinea and overthrusts the oceanic lithosphere of the Bismarck Sea. Along the New Guinea Trench, west of 144°E, seismicity defines a southward dipping Wadati-Benioif zone, and focal mechanisms indicate oblique

  4. Paleoceanographic changes in the Eastern Equatorial Pacific over the last 10 Myr

    OpenAIRE

    Seki, Osamu; Schmidt, Daniela N.; Schouten, Stefan; Hopmans, Ellen C.; Damsté, Jaap S. Sinninghe; Pancost, Richard D.

    2012-01-01

    To examine the Late Neogene evolution of tropical Pacific oceanography, we determined multiple geochemical proxy records for temperature (U37^[K'] and TEX86^[H] indices) and primary productivity (algal biomarkers and diol indices) in sediments recovered at ODP Site 1241 in the East Equatorial Pacific (EEP) spanning a record of the last 10 Myr. The TEX86^[H] temperatures are lower than those recorded by U37^[K'] indices, exhibiting large fluctuations and suggesting strong warming during the Mi...

  5. Paleoceanographic changes in the Eastern Equatorial Pacific over the last 10 Myr

    OpenAIRE

    Seki, O.; Schmidt, D.N.; Schouten, S.; Hopmans, E.C.; Sinninghe Damsté, J.S.; Pancost, R.D.

    2012-01-01

    To examine the Late Neogene evolution of tropical Pacific oceanography, we determined multiple geochemical proxy records for temperature (U-37(K)' and TEX86H indices) and primary productivity (algal biomarkers and diol indices) in sediments recovered at ODP Site 1241 in the East Equatorial Pacific (EEP) spanning a record of the last 10 Myr. The TEX86H temperatures are lower than those recorded by U-37(K)' indices, exhibiting large fluctuations and suggesting strong warming during the Mid Plio...

  6. Quiet time equatorial F region vertical plasma drift model derived from ROCSAT-1 observations

    OpenAIRE

    Fejer, Bela G.; Jensen, J. W.; Su, S.Y.

    2008-01-01

    [1] We have used five years of measurements on board the ROCSAT-1 satellite to develop a detailed quiet time global empirical model for equatorial F region vertical plasma drifts. This model describes the local time, seasonal and longitudinal dependence of the vertical drifts for an altitude of 600 km under moderate and high solar flux conditions. The model results are in excellent agreement with measurements from the Jicamarca radar and also from other ground-based and in situ probes. We sho...

  7. The effect of non-migrating tides on the equatorial electrojet

    OpenAIRE

    Hermann Lühr; Martin Rother; Häusler, K.; Alken, P.; Maus, S.

    2008-01-01

    The climatological model of the equatorial electrojet, EEJM-1, derived from Ørsted, CHAMP and SAC-C satellite measurements [Alken and Maus, 2007] provides the opportunity to investigate the longitudinal variation of the current strength in detail. Special emphasis is put in this paper on the effect of non-migrating tides. We have found that the influence of the diurnal eastward propagating mode with wavenumber 3, DE3, is particularly strong. In polar orbiting satellite observations the DE3 ti...

  8. RESULTS OF OZONE OBSERVATION FROM THE EQUATORIAL REGION TO ANTARCTICA IN 1987

    OpenAIRE

    マツバラ, コウジ; ドイ, モトヒサ; ウエクボ, テツロウ; オカダ, ケンジ; アオキ, シュンジ; カワグチ, サダオ; Kouji, Matsubara; Motohisa, DOI; Tetsuro, UEKUBO; Kenji, Okada; Shuhji, AOKI; Sadao, KAWAGUCHI

    1991-01-01

    The first total ozone observation and vertical ozone sounding on board the research vessel 'SHIRASE' from the equatorial region to Antarctica was carried out in 1987 by meteorological members of the 29th JARE (Japanese Antarctic Research Expedition) team. Total ozone and vertical ozone profile were measured by Brewer ozone spectrophotometer and ozonesondes, respectively. The detailed latitudinal distribution of total ozone amount and height-latitude distributions of ozone concentration, tempe...

  9. Numerical analysis of global ionospheric current system including the effect of equatorial enhancement

    Directory of Open Access Journals (Sweden)

    S. Tsunomura

    Full Text Available A modeling method is proposed to derive a two-dimensional ionospheric layer conductivity, which is appropriate to obtain a realistic solution of the polar-originating ionospheric current system including equatorial enhancement. The model can be obtained by modifying the conventional, thin shell conductivity model. It is shown that the modification for one of the non-diagonal terms (Σθφ in the conductivity tensor near the equatorial region is very important; the term influences the profile of the ionospheric electric field around the equator drastically. The proposed model can reproduce well the results representing the observed electric and magnetic field signatures of geomagnetic sudden commencement. The new model is applied to two factors concerning polar-originating ionospheric current systems. First, the latitudinal profile of the DP2 amplitude in the daytime is examined, changing the canceling rate for the dawn-to-dusk electric field by the region 2 field-aligned current. It is shown that the equatorial enhancement would not appear when the ratio of the total amount of the region 2 field-aligned current to that of region 1 exceeds 0.5. Second, the north-south asymmetry of the magnetic fields in the summer solstice condition of the ionospheric conductivity is examined by calculating the global ionospheric current system covering both hemispheres simultaneously. It is shown that the positive relationship between the magnitudes of high latitude magnetic fields and the conductivity is clearly seen if a voltage generator is given as the source, while the relationship is vague or even reversed for a current generator. The new model, based on the International Reference Ionosphere (IRI model, can be applied to further investigations in the quantitative analysis of the magnetosphere-ionosphere coupling problems.

    Key words. Ionosphere (electric fields and currents; equatorial ionosphere; ionosphere

  10. Equatorial plasma bubbles and L-band scintillations in Africa during solar minimum

    Directory of Open Access Journals (Sweden)

    L. L. N. Amaeshi

    2012-04-01

    Full Text Available We report on the longitudinal, local time and seasonal occurrence of equatorial plasma bubbles (EPBs and L band (GPS scintillations over equatorial Africa. The measurements were made in 2010, as a first step toward establishing the climatology of ionospheric irregularities over Africa. The scintillation intensity is obtained by measuring the standard deviation of normalized GPS signal power. The EPBs are detected using an automated technique, where spectral analysis is used to extract and identify EPB events from the GPS TEC measurements.

    Overall, the observed seasonal climatology of the EPBs as well as GPS scintillations in equatorial Africa is adequately explained by geometric arguments, i.e., by the alignment of the solar terminator and local geomagnetic field, or STBA hypothesis (Tsunoda, 1985, 2010a. While plasma bubbles and scintillations are primarily observed during equinoctial periods, there are longitudinal differences in their seasonal occurrence statistics. The Atlantic sector has the most intense, longest lasting, and highest scintillation occurrence rate in-season. There is also a pronounced increase in the EPB occurrence rate during the June solstice moving west to east. In Africa, the seasonal occurrence shifts towards boreal summer solstice, with fewer occurrences and shorter durations in equinox seasons. Our results also suggest that the occurrence of plasma bubbles and GPS scintillations over Africa are well correlated, with scintillation intensity depending on depletion depth. A question remains about the possible physical mechanisms responsible for the difference in the occurrence phenomenology of EPBs and GPS scintillations between different regions in equatorial Africa.

  11. Equatorial Oceanic Waves and the Evolution of 2007 Positive Indian Ocean Dipole

    Directory of Open Access Journals (Sweden)

    Iskhaq Iskandar

    2014-01-01

    Full Text Available The role of equatorial oceanic waves on the evolution of the 2007 positive Indian Ocean Dipole (pIOD event was evaluated using available observations and output from a quasi-analytical linear wave model. It was found that the 2007 pIOD event was a weak and short-lived event: developed in the mid-summer (July, matured in the early-fall (September, and terminated in the mid-fall (October. The evolution of the 2007 pIOD event was linked to the equatorial wave dynamics. The event development was associated with the generation of upwelling equatorial Kelvin waves (westward current anomalies generated by easterly wind anomalies. The event termination was associated with the occurrence of eastward zonal current anomalies resulting from a complex interplay between the wind-forced down welling Kelvin waves and the eastern-boundary-reflected Rossby waves. Results from a quasi-analytical linear wave model show that during the event development and maturation, the wind-forced Kelvin waves played a dominant role in generating zonal current anomalies along the equatorial Indian Ocean, while the eastern-boundary-reflected Rossby waves tended to weaken the wind-forced Kelvin wave signals. During the event termination our model shows that the initiation of anomalous eastward current resulted from the reflected Rossby waves at the eastern boundary. The wind-forced Kelvin waves associated with the seasonal reversal of the monsoon further strengthened the eastward zonal currents generated by the boundary-generated Rossby waves in late-October/early-November. This highlights the importance of the eastern-boundary-reflected Rossby waves on the IOD event termination.

  12. Characteristics of penetration electric fields to the equatorial ionosphere during southward and northward IMF turnings

    Science.gov (United States)

    Bhaskar, Ankush; Vichare, Geeta

    2013-07-01

    The signatures of abrupt turnings of the vertical component of the interplanetary magnetic field (IMF), Bz, can be seen at equatorial latitudes through the prompt transmission of high-latitude electric fields to the lower latitudes, called as prompt penetration electric field (PPE). The present work studies the signatures of PPE in daytime equatorial electrojet (EEJ) index derived in the Indian sector during 2001-2005. The signatures are observed in polar (PCN index) and equatorial (EEJ index) ionosphere almost instantaneously (<1 min). The communication time of 12±6 min is observed between bow shock nose and the equatorial ionosphere, and it is found to have inverse relationship with radial component of solar wind velocity during southward and northward Bz turnings which might indicate magnetosphere crossing time scale by solar wind. Ionospheric reconfiguration time during southward turnings shows inverse relationship with solar wind flow in contrast to northward turnings with "no relationship," indicating differences in underlying physical mechanisms during both turnings. We observe no local time dependence (within 06-18 h) in conductivity-corrected EEJ signatures associated with Bz turnings. Regression analysis between conductivity-corrected EEJ and interplanetary electric field shows higher efficiency during northward turnings. However, further analysis investigating the effect of actual orientation of Bz indicates that the magnitude of northward Bz does not have influence on the ionospheric signatures. It is noticed that the response signatures are mainly controlled by the magnitudes of southward Bz. Thus, the present study signifies the role of inner magnetospheric shielding electric field in addition to ceasing of convection during northward turnings.

  13. Electrodynamics of the equatorial F-region ionosphere during pre-sunrise period

    OpenAIRE

    S. R. Prabhakaran Nayar; T. J. Mathew; C. V. Sreehari; S. G. Sumod; Devasia, C. V.; Ravindran, S.; V. Sreeja; T. Kumar Pant; Sridharan, R.

    2009-01-01

    The electrodynamics of the pre-sunrise equatorial F-region is investigated using HF Doppler radar and digital ionosonde. The observations are limited to those days for which the radar probing frequency is below the foF2 value. The ionosphere observation using HF Doppler radar exhibit interesting features during pre-sunrise period similar to the post sunset pre-reversal enhancement. The most striking feature observed during pre-sunrise period is the sudden downward excursion...

  14. Evolution of nutricline dynamics in the equatorial Pacific during the late Pliocene

    Science.gov (United States)

    Bolton, C. T.; Gibbs, S.; Wilson, P.

    2009-12-01

    The tropics have played a central role in modulating Earth’s climate throughout the Plio-Pleistocene, with tropical productivity fluctuations a key mechanism in the operation of the global carbon cycle and linkage of high and low latitude climates. Published records of tropical sea surface temperatures (SSTs) during the Plio-Pleistocene appear to vary primarily in tune with high latitude climate both on orbital and secular timescales. Yet contemporaneous changes in equatorial primary productivity are less well constrained, particularly at sites where climate is not dominated by upwelling or monsoon systems. Furthermore, the role of thermocline dynamics (tilt and mean depth changes) in forcing SST and productivity on orbital timescales remains uncertain. Here we report new, high-resolution calcareous nannofossil records from two Ocean Drilling Program (ODP) sites in the western and eastern equatorial Pacific (WEP, EEP) during marine isotope stages (MIS) 95 to 101; about 2400 to 2600 thousand years ago (ka). Our records of paleoproductivity and nutricline depth reveal synchronous, large-amplitude glacial-interglacial (G-IG) productivity variations at both ends of the equatorial Pacific indicating (i) remote (high latitude) forcing of primary productivity and (ii) no primary role for east-west tilting of the equatorial Pacific thermocline, with important implications regarding the operation of El Niño-like dynamics in the Pliocene Pacific. Instead, the paleoproductivity variations and phase relationships that we document suggest the interaction of two mechanisms operating on obliquity timescales: a ‘bottom-up’ forcing transmitted via the upwelling of high latitude source waters in conjunction with the ‘top-down’ forcing of atmospheric greenhouse gases.

  15. A new starting point for the South and Equatorial Atlantic Ocean

    OpenAIRE

    Moulin, Maryline; Aslanian, Daniel; Unternehr, Patrick

    2010-01-01

    The opening of the Equatorial and South Atlantic Oceans is still a matter of debate, particularly as concerns the locations of the intraplate deformation. We propose here a critical review of the kinematic models published since Bullard et al., 1965, based on a series of constraints: new interpretation of the magnetic anomalies, seafloor isochrons, flow lines, fracture zones, continental and oceanic homologous structures and radiometric dating of igneous rocks. All of these models present num...

  16. Diversity and endemism of woody plant species in the Equatorial Pacific seasonally dry forests

    OpenAIRE

    Linares-Palomino, Reynaldo; Kvist, Lars; Aguirre-Mendoza, Zhofre; Gonzales-Inca, Carlos

    2009-01-01

    The biodiversity hotspot of the Equatorial Pacific region in western Ecuador and northwestern Peru comprises the most extensive seasonally dry forest formations west of the Andes. Based on a recently assembled checklist of the woody plants occurring in this region, we analysed their geographical and altitudinal distribution patterns. The montane seasonally dry forest region (at an altitude between 1,000 and 1,100 m, and the smallest in terms of area) was outstanding in terms of total species ...

  17. Reflection of equatorial Kelvin waves at eastern ocean boundaries Part II: Pacific and Atlantic Oceans

    OpenAIRE

    Soares, J.; I. Wainer; N. C. Wells

    1999-01-01

    The effect of viscosity, non linearities, incident wave period and realistic eastern coastline geometry on energy fluxes are investigated using a shallow water model with a spatial resolution of 1/4 degree in both meridional and zonal directions. Equatorial and mid-latitude responses are considered. It is found that (1) the influence of the coastline geometry and the incident wave period is more important for the westward energy flux than for the poleward flux, and (2) the effect of the incli...

  18. Gyroscope precession along bound equatorial plane orbits around a Kerr black hole

    Science.gov (United States)

    Bini, Donato; Geralico, Andrea; Jantzen, Robert T.

    2016-09-01

    The precession of a test gyroscope along stable bound equatorial plane orbits around a Kerr black hole is analyzed, and the precession angular velocity of the gyro's parallel transported spin vector and the increment in the precession angle after one orbital period is evaluated. The parallel transported Marck frame which enters this discussion is shown to have an elegant geometrical explanation in terms of the electric and magnetic parts of the Killing-Yano 2-form and a Wigner rotation effect.

  19. On meridional circulation and heat budget of the troposphere over the Equatorial Central Pacific

    OpenAIRE

    Hastenrath, Stefan L.

    2011-01-01

    The existence of an equatorial dry zone in the Central Pacific enclosed between moister belts in both hemispheres is borne out by rainfall measurements and daily ESSA III and ESSA V cloud mosaics. The tropospheric wind regime is studied mainly on the basis of aerological soundings during the Line Islands Experiment (LIE) in spring 1967 and observations of earlier periods. During LIE, upper-tropospheric Westerlies extend continuously across the equator. In the lower layers, Easterlies dominate...

  20. A study of evolution/suppression parameters of equatorial postsunset plasma instability

    Directory of Open Access Journals (Sweden)

    O. S. Oyekola

    2009-01-01

    Full Text Available Evening equatorial pre-reversal vertical ion E×B drift (VZP and the peak of the ionospheric F2 maximum altitude (hmF2P of the postsunset equatorial F-layer, which are the essential parameters requisite for the generation or inhibition of postsunset bottomside equatorial irregularities were deduced from ionosonde observations made in the Africa region (Ouagadougou: ~3° N dip latitude between January 1987 and December 1990 for solar activity minimum, medium, and maxima (F10.7=85, 141, 214, and 190, respectively for quiet geomagnetic conditions. We investigate variations of evening equatorial pre-reversal drift and the corresponding altitude at four levels of solar activity. Our observations show strong variations with solar variability. Correlation analysis between these parameters indicates that the correlation coefficient value between hmF2P versus VZP decreases considerably with increasing solar flux value. There seems to be no significant link between these parameters under high solar activity, especially for solar intensity F10.7>200 units. We conclude that meridional neutral wind in the F-region contributes substantially to the variations of the pre-reversal vertical plasma drifts enhancement and the peak hmF2, particularly the electrodynamics during twilight high solar flux conditions.

  1. Gyroscope precession along unbound equatorial plane orbits around a Kerr black hole

    CERN Document Server

    Bini, Donato; Jantzen, Robert T

    2016-01-01

    The precession of a test gyroscope along unbound equatorial plane geodesic orbits around a Kerr black hole is analyzed with respect to a static reference frame whose axes point towards the "fixed stars." The accumulated precession angle after a complete scattering process is evaluated and compared with the corresponding change in the orbital angle. Limiting results for the non-rotating Schwarzschild black hole case are also discussed.

  2. Gyroscope precession along bound equatorial plane orbits around a Kerr black hole

    CERN Document Server

    Bini, Donato; Jantzen, Robert T

    2016-01-01

    The precession of a test gyroscope along stable bound equatorial plane orbits around a Kerr black hole is analyzed and the precession angular velocity of the gyro's parallel transported spin vector and the increment in precession angle after one orbital period is evaluated. The parallel transported Marck frame which enters this discussion is shown to have an elegant geometrical explanation in terms of the electric and magnetic parts of the Killing-Yano 2-form and a Wigner rotation effect.

  3. Reproduction and recruitment of scleractinian corals on equatorial reefs in Mombasa, Kenya.

    OpenAIRE

    Mangubhai, Sangeeta

    2007-01-01

    This study examined patterns of coral reproduction and recruitment on lagoonal reefs adjacent to Mombasa in Kenya, at latitude 4ºS. Very little detailed research has been done on the reproductive patterns of scleractinian corals on equatorial reefs, where it has been suggested that seasonality and spawning synchrony may break down due to the weak environmental cues that are thought to govern the onset and timing of reproduction. Gametogenic data were collected for three faviid (Echinopora gem...

  4. Polar and equatorial coronal hole winds at solar minima: From the heliosphere to the inner corona

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.; Landi, E., E-mail: lzh@umich.edu [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48105 (United States)

    2014-02-01

    Fast solar wind can be accelerated from at least two different sources: polar coronal holes and equatorial coronal holes. Little is known about the relationship between the wind coming from these two different latitudes and whether these two subcategories of fast wind evolve in the same way during the solar cycle. Nineteen years of Ulysses observations, from 1990 to 2009, combined with ACE observations from 1998 to the present provide us with in situ measurements of solar wind properties that span two entire solar cycles. These missions provide an ideal data set to study the properties and evolution of the fast solar wind originating from equatorial and polar holes. In this work, we focus on these two types of fast solar wind during the minima between solar cycles 22 and 23 and 23 and 24. We use data from SWICS, SWOOPS, and VHM/FGM on board Ulysses and SWICS, SWEPAM, and MAG on board ACE to analyze the proton kinetic, thermal, and dynamic characteristics, heavy ion composition, and magnetic field properties of these two fast winds. The comparison shows that: (1) their kinetic, thermal, compositional, and magnetic properties are significantly different at any time during the two minima and (2) they respond differently to the changes in solar activity from cycle 23 to 24. These results indicate that equatorial and polar fast solar wind are two separate subcategories of fast wind. We discuss the implications of these results and relate them to remote-sensing measurements of the properties of polar and equatorial coronal holes carried out in the inner corona during these two solar minima.

  5. Polar and Equatorial Coronal Hole Winds at Solar Minima: From the Heliosphere to the Inner Corona

    Science.gov (United States)

    Zhao, L.; Landi, E.

    2014-02-01

    Fast solar wind can be accelerated from at least two different sources: polar coronal holes and equatorial coronal holes. Little is known about the relationship between the wind coming from these two different latitudes and whether these two subcategories of fast wind evolve in the same way during the solar cycle. Nineteen years of Ulysses observations, from 1990 to 2009, combined with ACE observations from 1998 to the present provide us with in situ measurements of solar wind properties that span two entire solar cycles. These missions provide an ideal data set to study the properties and evolution of the fast solar wind originating from equatorial and polar holes. In this work, we focus on these two types of fast solar wind during the minima between solar cycles 22 and 23 and 23 and 24. We use data from SWICS, SWOOPS, and VHM/FGM on board Ulysses and SWICS, SWEPAM, and MAG on board ACE to analyze the proton kinetic, thermal, and dynamic characteristics, heavy ion composition, and magnetic field properties of these two fast winds. The comparison shows that: (1) their kinetic, thermal, compositional, and magnetic properties are significantly different at any time during the two minima and (2) they respond differently to the changes in solar activity from cycle 23 to 24. These results indicate that equatorial and polar fast solar wind are two separate subcategories of fast wind. We discuss the implications of these results and relate them to remote-sensing measurements of the properties of polar and equatorial coronal holes carried out in the inner corona during these two solar minima.

  6. Investigation of Jupiter's Equatorial Hotspots and Plumes Using Cassini ISS Observations

    Science.gov (United States)

    Choi, David S.; Showman, A. P.; Vasavada, A. R.; Simon-Miller, A. A.

    2012-01-01

    We present updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the ISS onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial 5-micron hot spots and their interactions with adjacent latitudes. Hot spots are quasi-stable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but a diffuse western edge serving as a nebulous boundary with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-iike 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. This raises the possibility that the plumes and fast-moving clouds are at higher altitudes, because their speed does not match previously published zonal wind profiles. Most profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby waves controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed. Instead, our expanded data set demonstrating the rapid flow of these scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. This research was supported by a NASA JDAP grant and the NASA Postdoctoral Program.

  7. Seasonal variation of the surface North Equatorial Countercurrent (NECC) in the western Pacific Ocean

    Science.gov (United States)

    Zhao, Jun; Li, Yuanlong; Wang, Fan

    2016-03-01

    The North Equatorial Countercurrent (NECC) is an important zonal flow in the upper circulation of the tropical Pacific Ocean, which plays a vital role in the heat budget of the western Pacific warm pool. Using satellite-derived data of ocean surface currents and sea surface heights (SSHs) from 1992 to 2011, the seasonal variation of the surface NECC in the western tropical Pacific Ocean was investigated. It was found that the intensity (INT) and axis position (Y CM) of the surface NECC exhibit strikingly different seasonal fluctuations in the upstream (128°-136°E) and downstream (145°-160°E) regions. Of the two regions, the seasonal cycle of the upstream NECC shows the greater interannual variability. Its INT and YCM are greatly influenced by variations of the Mindanao Eddy, Mindanao Dome (MD), and equatorial Rossby waves to its south. Both INT and Y CM also show semiannual signals induced by the combined effects of equatorial Rossby waves from the Central Pacific and local wind forcing in the western Pacific Ocean. In the downstream region, the variability of the NECC is affected by SSH anomalies in the MD and the central equatorial Pacific Ocean. Those in the MD region are especially important in modulating the YCM of the downstream NECC. In addition to the SSH-related geostrophic flow, zonal Ekman flow driven by meridional wind stress also plays a role, having considerable impact on INT variability of the surface NECC. The contrasting features of the variability of the NECC in the upstream and downstream regions reflect the high complexity of regional ocean dynamics.

  8. Surprising detection of an equatorial dust lane on the AGB star IRC+10216

    Science.gov (United States)

    Jeffers, S. V.; Min, M.; Waters, L. B. F. M.; Canovas, H.; Pols, O. R.; Rodenhuis, M.; de Juan Ovelar, M.; Keller, C. U.; Decin, L.

    2014-12-01

    Aims: Understanding the formation of planetary nebulae remains elusive because in the preceding asymptotic giant branch (AGB) phase these stars are heavily enshrouded in an optically thick dusty envelope. Methods: To further understand the morphology of the circumstellar environments of AGB stars we observe the closest carbon-rich AGB star IRC+10216 in scattered light. Results: When imaged in scattered light at optical wavelengths, IRC+10216 surprisingly shows a narrow equatorial density enhancement, in contrast to the large-scale spherical rings that have been imaged much further out. We use radiative transfer models to interpret this structure in terms of two models: firstly, an equatorial density enhancement, commonly observed in the more evolved post-AGB stars, and secondly, in terms of a dust rings model, where a local enhancement of mass-loss creates a spiral ring as the star rotates. Conclusions: We conclude that both models can be used to reproduce the dark lane in the scattered light images, which is caused by an equatorially density enhancement formed by dense dust rather than a bipolar outflow as previously thought. We are unable to place constraints on the formation of the equatorial density enhancement by a binary system. Final reduced images (FITS) are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/572/A3Based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

  9. On the role of the cross equatorial flow on summer monsoon rainfall over India using NCEP/NCAR reanalysis data

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Shenoi, S.S.C.; Schluessel, P.

    the cross equatorial flow and moisture flow into the Indian subcontinent during the monsoon season, but it fails to depict these differences during excess (1983, 1988, 1994) and deficit monsoon (1982, 1986, 1987) composites. Further, it is seen that inter...

  10. Iron bacterial phylogeny and their execution towards iron availability in Equatorial Indian Ocean and Coastal Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasabapathy, R.; Mohandass, C.; VijayRaj, A.S.; Madival, V.V.; Meena, R.M.

    Author version: Polish J. Microbiol., vol.62(4); 2013; 391-400 Iron bacterial phylogeny and their execution towards iron availability in Equatorial Indian Ocean and Coastal Arabian Sea RAJU RAJASABAPATHY, CHELLANDI MOHANDASS*, AJAKKALAMOOLE...

  11. Response of the equatorial Pacific to chlorophyll pigment in a mixed layer isopycnal ocean general circulation model

    Digital Repository Service at National Institute of Oceanography (India)

    Nakamoto, S.; PrasannaKumar, S.; Oberhuber, J.M.; Ishizaka, J.; Muneyama, K.; Frouin, R.

    The influence of phytoplankton on the upper ocean dynamics and thermodynamics in the equatorial Pacific is investigated using an isopycnal ocean general circulation model (OPYC) coupled with a mixed layer model and remotely sensed chlorophyll...

  12. {sup 10}Be/{sup 230}Th ratios as proxy for particle flux in the equatorial Pacific ocean

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.F.; Fleisher, M.Q. [LDEO of Columbia Univ. (United States); Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Suter, M. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Particulate {sup 10}Be/{sup 230}Th ratios collected by sediment traps in the central equatorial Pacific Ocean exhibit a positive correlation with particle flux, but little or no correlation with particle composition. (author) 1 fig., 4 refs.

  13. Using citizen science reports to define the equatorial extent of auroral visibility

    Science.gov (United States)

    Case, N. A.; MacDonald, E. A.; Viereck, R.

    2016-03-01

    An aurora may often be viewed hundreds of kilometers equatorward of the auroral oval owing to its altitude. As such, the NOAA Space Weather Prediction Center (SWPC) Aurora Forecast product provides a "view line" to demonstrate the equatorial extent of auroral visibility, assuming that it is sufficiently bright and high in altitude. The view line in the SWPC product is based upon the latitude of the brightest aurora, for each hemisphere, as specified by the real-time oval variation, assessment, tracking, intensity, and online nowcasting (OVATION) Prime (2010) aurora precipitation model. In this study, we utilize nearly 500 citizen science auroral reports to compare with the view line provided by an updated SWPC aurora forecast product using auroral precipitation data from OVATION Prime (2013). The citizen science observations were recorded during March and April 2015 using the Aurorasaurus platform and cover one large geomagnetic storm and several smaller events. We find that this updated SWPC view line is conservative in its estimate and that the aurora is often viewable further equatorward than is indicated by the forecast. By using the citizen reports to modify the scaling parameters used to link the OVATION Prime (2013) model to the view line, we produce a new view line estimate that more accurately represents the equatorial extent of visible aurora. An OVATION Prime (2013) energy flux-based equatorial boundary view line is also developed and is found to provide the best overall agreement with the citizen science reports, with an accuracy of 91%.

  14. Mid-Pliocene equatorial Pacific sea surface temperature reconstruction: a multi-proxy perspective

    Science.gov (United States)

    Dowsett, Harry J.; Robinson, Marci M.

    2009-01-01

    The Mid-Pliocene is the most recent interval of sustained global warmth, which can be used to examine conditions predicted for the near future. An accurate spatial representation of the low-latitude Mid-Pliocene Pacific surface ocean is necessary to understand past climate change in the light of forecasts of future change. Mid-Pliocene sea surface temperature (SST) anomalies show a strong contrast between the western equatorial Pacific (WEP) and eastern equatorial Pacific (EEP) regardless of proxy (faunal, alkenone and Mg/Ca). All WEP sites show small differences from modern mean annual temperature, but all EEP sites show significant positive deviation from present-day temperatures by as much as 4.4°C. Our reconstruction reflects SSTs similar to modern in the WEP, warmer than modern in the EEP and eastward extension of the WEP warm pool. The east-west equatorial Pacific SST gradient is decreased, but the pole to equator gradient does not change appreciably. We find it improbable that increased greenhouse gases (GHG) alone would cause such a heterogeneous warming and more likely that the cause of Mid-Pliocene warmth is a combination of several forcings including both increased meridional heat transport and increased GHG.

  15. Measuring the magnetic field of a trans-equatorial loop system using coronal seismology

    Science.gov (United States)

    Long, David; Perez-Suarez, David; Valori, Gherardo

    2016-05-01

    First observed by SOHO/EIT, "EIT waves" are strongly associated with the initial evolution of coronal mass ejections (CMEs) and after almost 20 years of investigation a consensus is being reached which interprets them as freely-propagating waves produced by the rapid expansion of a CME in the low corona. An "EIT wave" was observed on 6 July 2012 to erupt from active region AR11514 into a particularly structured corona that included multiple adjacent active regions as well as an adjacent trans-equatorial loop system anchored at the boundary of a nearby coronal hole. The eruption was well observed by SDO/AIA and CoMP, allowing the effects of the "EIT wave" on the trans-equatorial loop system to be studied in detail. In particular, it was possible to characterise the oscillation of the loop system using Doppler velocity measurements from CoMP. These Doppler measurements were used to estimate the magnetic field strength of the trans-equatorial loop system via coronal seismology. It was then possible to compare these inferred magnetic field values with extrapolated magnetic field values derived using a Potential Field Source Surface extrapolation as well as the direct measurements of magnetic field provided by CoMP. These results show that the magnetic field strength of loop systems in the solar corona may be estimated using loop seismology.

  16. Fault evolution in the Potiguar rift termination, Equatorial margin of Brazil

    Directory of Open Access Journals (Sweden)

    D. L. de Castro

    2014-10-01

    Full Text Available The transform shearing between South American and African plates in the Cretaceous generated a series of sedimentary basins on both plate margins. In this study, we use gravity, aeromagnetic, and resistivity surveys to identify fault architecture and to analyse the evolution of the eastern Equatorial margin of Brazil. Our study area is the southern onshore termination of the Potiguar rift, which is an aborted NE-trending rift arm developed during the breakup of Pangea. The Potiguar rift is a Neocomian structure located in the intersection of the Equatorial and western South Atlantic and is composed of a series of NE-trending horsts and grabens. This study reveals new grabens in the Potiguar rift and indicates that stretching in the southern rift termination created a WNW-trending, 10 km wide and ~40 km long right-lateral strike-slip fault zone. This zone encompasses at least eight depocenters, which are bounded by a left-stepping, en-echelon system of NW- to EW-striking normal faults. These depocenters form grabens up to 1200 m deep with a rhomb-shaped geometry, which are filled with rift sedimentary units and capped by post-rift sedimentary sequences. The evolution of the rift termination is consistent with the right-lateral shearing of the Equatorial margin in the Cretaceous and occurs not only at the rift termination, but also as isolated structures away from the main rift.

  17. Variability of foE in the equatorial ionosphere with solar activity

    Science.gov (United States)

    Abe, O. E.; Rabiu, A. B.; Adeniyi, J. O.

    2013-01-01

    This research examined the variability of foE in the equatorial ionosphere with solar activity within the equatorial ionospheric anomaly region. Ionosonde data recorded at Ouagadougou (lat. 12.4°N, long. 1.5°W and magnetic dip 1.43°N) were engaged to study the transient variations of the critical frequency of the E-layer (foE) and its dependence on solar activity. The study revealed that foE increases with the increase in solar intensity of the sun. The variability of the foE decreases with increases in the solar activity. The maximum value of the foE is at local noon when the ionosphere is stable; the variability at this local time is minimal. The minimum value of the foE is at sunrise and sunset, at this period on local time the equatorial ionosphere recorded its maxima variability. Irrespective of the degree of solar activity, foE is observed to be maximum in June solstice, followed by the equinoxes and minimum in December solstice. Equinoctial asymmetry occurred in the variation of the relative standard deviation of foE with maximum in September/March equinox for low/high solar activity.

  18. Association between earthquake and equatorial waves in Outgoing Longwave Radiation over South East Asia

    Science.gov (United States)

    Yadav, Manohar Lal

    In the present study, efforts has been made to correlate the equatorial planetary waves in Outgoing Longwave Radiation (OLR) and to seismic activities in South East Asian region. The OLR data has been obtained from NOAA Climate Prediction Centre web site. The earthquake information has been obtained from USGS earthquake information centre. This paper present observations for the two earthquakes, i.e., 26 January 2001, Bhuj, India and 26 December 2004, Sumatra, Indonesia. The normal days OLR has been compared to the OLR recorded during the seismic events. It has been observed that there is significant enhancement in OLR, few days before the earthquake event. The Morlet 6.6 wavelet analysis shows the presence of planetary waves in equatorial OLR for period about 6 days, during and about 80 days before the earthquake. The OLR data were analysed in such a way that the other possible effects are minimized. The anomalous increase and presence of planetary waves before 80 days of seismic event shows great potential in providing early warning of a disastrous earthquake. It should be noted that planetary waves is generated only in the equatorial region irrespective of strong/severe earthquake location.

  19. OH Airglow and Equatorial Variations Observed by ISUAL Instrument on Board the FORMOSAT 2 Satellite

    Directory of Open Access Journals (Sweden)

    Jan-Bai Nee

    2010-01-01

    Full Text Available OH airglow observed by the ISUAL (Imager of Sprites and Upper Atmospheric Lightning instrument on board the FORMOSAT 2 satellite is reported in this paper. The satellite is sun-synchronous and it returns to the same orbit at the same local time daily. By using this property, we can study the upper atmosphere in detail. With a CCD camera, ISUAL has measured the emission layers of OH Meinel band at 630 nm for several two-week periods in 2004 and 2007 in equatorial regions. ISUAL images are snapshots of the atmosphere 250 km (height _ 1200 km (horizontal distance. These images of OH airglow are analyzed to derive its peak height and latitudinal variations. ISUAL observation is unique in its capability of continuous observation of the upper atmosphere as the satellite travels from south to north along a specific orbit. However, 630 nm filter also measured O(1D at 200 km, and there are interferences between O(1D and OH airglows as as observed from a distance in space. We have studied the overlap of two airglows by simulations, and our final analyses show that OH airglow can be correctly derived with its average peak height of 89 _ 2.1 km usually lying within _ latitude about the equator. ISUAL data reveal detailed structures of equatorial OH airglow such as the existences of a few secondary maxima within the equatorial regions, and the oscillations of the peak latitudes. These results are discussed and compared with previous reports.

  20. The ultra-fast Kelvin waves in the equatorial ionosphere: observations and modeling

    Directory of Open Access Journals (Sweden)

    A. N. Onohara

    2013-02-01

    Full Text Available The main purpose of this study is to investigate the vertical coupling between the mesosphere and lower thermosphere (MLT region and the ionosphere through ultra-fast Kelvin (UFK waves in the equatorial atmosphere. The effect of UFK waves on the ionospheric parameters was estimated using an ionospheric model which calculates electrostatic potential in the E-region and solves coupled electrodynamics of the equatorial ionosphere in the E- and F-regions. The UFK wave was observed in the South American equatorial region during February–March 2005. The MLT wind data obtained by meteor radar at São João do Cariri (7.5° S, 37.5° W and ionospheric F-layer bottom height (h'F observed by ionosonde at Fortaleza (3.9° S; 38.4° W were used in order to calculate the wave characteristics and amplitude of oscillation. The simulation results showed that the combined electrodynamical effect of tides and UFK waves in the MLT region could explain the oscillations observed in the ionospheric parameters.