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  1. 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

  2. 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

  3. 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

  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. 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.

  6. 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

  7. Outdoor host seeking behaviour of Anopheles gambiae mosquitoes following initiation of malaria vector control on Bioko Island, Equatorial Guinea

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    Reddy Vamsi P

    2011-07-01

    Full Text Available Abstract Background Indoor-based anti-vector interventions remain the preferred means of reducing risk of malaria transmission in malaria endemic areas around the world. Despite demonstrated success in reducing human-mosquito interactions, these methods are effective solely against endophilic vectors. It may be that outdoor locations serve as an important venue of host seeking by Anopheles gambiae sensu lato (s.l. mosquitoes where indoor vector suppression measures are employed. This paper describes the host seeking activity of anopheline mosquito vectors in the Punta Europa region of Bioko Island, Equatorial Guinea. In this area, An. gambiae sensu stricto (s.s. is the primary malaria vector. The goal of the paper is to evaluate the importance of An gambiae s.l. outdoor host seeking behaviour and discuss its implications for anti-vector interventions. Methods The venue and temporal characteristics of host seeking by anopheline vectors in a hyperendemic setting was evaluated using human landing collections conducted inside and outside homes in three villages during both the wet and dry seasons in 2007 and 2008. Additionally, five bi-monthly human landing collections were conducted throughout 2009. Collections were segregated hourly to provide a time distribution of host-seeking behaviour. Results Surprisingly high levels of outdoor biting by An. gambiae senso stricto and An. melas vectors were observed throughout the night, including during the early evening and morning hours when human hosts are often outdoors. As reported previously, An. gambiae s.s. is the primary malaria vector in the Punta Europa region, where it seeks hosts outdoors at least as much as it does indoors. Further, approximately 40% of An. gambiae s.l. are feeding at times when people are often outdoors, where they are not protected by IRS or LLINs. Repeated sampling over two consecutive dry-wet season cycles indicates that this result is independent of seasonality. Conclusions

  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. 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.

  10. 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.

  11. 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

  12. 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...

  13. Radiation protection in hospitals of Equatorial Guinea

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    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)

  14. Las labiadas (Lamiaceae) de Guinea Ecuatorial

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    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...

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

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    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.

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

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    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...

  17. Filling a blank on the map: 60 years of fisheries in Equatorial Guinea

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    Belhabib, D.; Hellebrandt Da Silva, D.; Allison, E.H.; Zeller, D.; Pauly, D.

    2016-01-01

    Despite a scarcity of pertinent information, it has been possible to reconstruct time series of marine fisheries catches for Equatorial Guinea from 1950 to 2010 using per capita fish consumption and population numbers for small-scale fisheries, catch rates and number of vessels for industrial fisheries and discard rates to estimate the discarded bycatch. Small-scale fisheries, industrial large-scale fisheries, domestic and legal and illegal foreign fisheries and their discards are all include...

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

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

    2016-05-01

    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. PMID:26698540

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

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    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

  20. What does remain in Equatorial Guinea of the Spanish education? From the colonial education to the current reality

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    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.

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

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    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.

  2. Commercial bushmeat hunting in the Monte Mitra Forests, Equatorial Guinea: extent and impact

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    Fa, J. E.

    2001-06-01

    Full Text Available Understanding the exploitation of bushmeat by commercial hunters is fundamental to resolving hunting sustainability issues in African rainforests. The objective of this study was to examine the impact of hunters operating from the village of Sendje in the Monte Mitra region, Republic of Equatorial Guinea. Offtake patterns of 42 hunters were studied over a period of 16 months. A total of 3,053 animals of 58 species were hunted during 1,914 hunting days. This represented around 11,376 kg of bushmeat or 2,219 animals extracted per annum. Most captures were mammals (43 species, 79%, constituting 90% of the biomass hunted, of these 30% were ungulates and 27% were rodents. Hunters used 17 hunt camps within the 1,010 km2 total study area. Hunting activity fell from the start to the end of the study, with fewer hunting days, biomass and captures being recorded per month. Captures fell from 700 animals in the first month to less than 100 during the last month. Per hunter, returns diminished from 21 in the first month to around 13 animals from the third month. Average body mass of prey also declined throughout the study period. The principal hunting method was cable snaring -over 100 million snare nights were estimated. An average hunter extracted around 50 animals or 271 kg of bushmeat per annum. Hunter and camp differences were significant. Most carcasses were sold for the city market or to villagers, and the proportion of carcasses sold to market was positively correlated with the species body mass. Capture rates and vulnerability were dependent on prey size since medium¿sized animals were more vulnerable to be caught than small or large¿bodied animals. Harvest sustainability was calculated for 14 mammals and it was seen that the situation was unsustainably for 5 species due to the extent and impact of hunting. The bay duiker (Cephalophus dorsalis was by far the most heavily exploited species. Conservation of the Monte Mitra region is impossible

  3. Las labiadas (Lamiaceae de Guinea Ecuatorial

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    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

    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.

  6. 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...

  7. 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.

  8. 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.

  9. Bryophytes from the Republic of Equatorial Guinea (West Central Africa) : 4., notes on some nomina nuda from Annobon

    OpenAIRE

    Heras Pérez, Patxi; Infante Sánchez, Marta

    1999-01-01

    Eight moss species corresponding to nomina nuda recorded in the literature from Annobon Island are listed with their recent determination and current names. Leucophanes unguiculatum, Philonotis uncinata var. glaucescens and Vesicularia strephomischos are new records for the Equatorial Guinean bryoflora.

  10. 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.

  11. 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.

  12. 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

  13. 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...

  14. 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.

  15. 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)

  16. 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...

  17. 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

  18. Intermonsoonal equatorial jets

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.

    , respectively. Hydrographic features and transport computations favour a well developed equatorial jet during both seasons. The net surface eastward and subsurface westward flows are well balanced during the premonsoon transition period and appear...

  19. Atlantic Equatorial Deep Jets

    OpenAIRE

    Didwischus, Sven-Helge; Brandt, Peter; Greatbatch, Richard John

    2012-01-01

    The Equatorial Deep Jets (EDJ) are a dominant signal in the deep Atlantic at the equator. EDJs are vertical alternating zonal currents with a vertical wavelength of only a few hundred meters. They are found from below the Equatorial Undercurrent down to about 2500m. They were also observed in the Pacific and Indian Ocean. The EDJs are focused on the equator and have a meridional extent of about 1.5°S to 1.5°N. In the Atlantic, EDJs oscillate at a period of about 4.5 years as could be shown by...

  20. 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 ...

  1. 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.

  2. 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...

  3. 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.

  4. 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

  5. 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^{...

  6. 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 with...

  7. 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...

  8. 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.

  9. 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

  10. 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

  11. Optimal Broadcasting of Mixed Equatorial Qubits

    International Nuclear Information System (INIS)

    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. (general)

  12. 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.

  13. 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

  14. 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.

  15. Insulinoma in 2 guinea pigs (Cavia porcellus)

    OpenAIRE

    Vannevel, Janice Y.; Wilcock, Brian

    2005-01-01

    This paper describes an insulinoma in 2 guinea pigs (Cavia porcellus). Both guinea pigs presented with neurologic signs and low blood glucose readings. The neurologic signs resolved with dextrose administration. Insulinoma was confirmed on postmortem examination.

  16. Quantum cloning machines for equatorial qubits

    OpenAIRE

    Fan, Heng; Matsumoto, Keiji; Wang, Xiang-Bin; Wadati, Miki

    2001-01-01

    Quantum cloning machines for equatorial qubits are studied. For the case of 1 to 2 phase-covariant quantum cloning machine, we present the networks consisting of quantum gates to realize the quantum cloning transformations. The copied equatorial qubits are shown to be separable by using Peres-Horodecki criterion. The optimal 1 to M phase-covariant quantum cloning transformations are given.

  17. Tropospheric ozone over Equatorial Africa: regional aspects from the MOZAIC data

    Directory of Open Access Journals (Sweden)

    B. Sauvage

    2005-01-01

    Full Text Available We analyze ozone observations recorded over Equatorial Africa between April 1997 and March 2003 by the MOZAIC programme, providing the first ozone climatology deriving from continental in-situ data over this region. Three-dimensional streamlines strongly suggests connections between the characteristics of the ozone monthly mean vertical profiles, the most persistent circulation patterns in the troposphere over Equatorial Africa (on a monthly basis such as the Harmattan, the African Easterly Jet, the Trades and the regions of ozone precursors emissions by biomass burning. During the biomass burning season in each hemisphere, the lower troposphere exhibits layers of enhanced ozone (i.e. 70 ppbv over the coast of Gulf of Guinea in December-February and 85 ppbv over Congo in June-August. The characteristics of the ozone monthly mean vertical profiles are clearly connected to the regional flow regime determined by seasonal dynamic forcing. The mean ozone profile over the coast of Gulf of Guinea in the burning season is characterized by systematically high ozone below 650hPa ; these are due to the transport by the Harmattan and the AEJ of the pollutants originating from upwind fires. The confinement of high ozone to the lower troposphere is due to the high stability of the Harmattan and the blocking Saharan anticyclone which prevents efficient vertical mixing. In contrast, ozone enhancements observed over Central Africa during the local dry season (June-August are not only found in the lower troposphere but throughout the troposphere. Moreover, this study highlights a connection between the regions of the coast of Gulf of Guinea and regions of Congo to the south that appears on a semi annual basis. Vertical profiles in wet-season regions exhibit ozone enhancements in the lower troposphere due to biomass burning products transport from fires situated in the opposite dry-season hemisphere.

  18. 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...

  19. Vertical cloud structure of Jupiter's equatorial plumes

    Science.gov (United States)

    Stoker, C. R.; Hord, C.

    1985-01-01

    Multiple-scattering radiative transfer calculations were used to deduce the vertical cloud structure (VCS) of Jupiter's equatorial region. The VCS model of the equatorial plumes is obtained through an analysis of Voyager images of the 6190-A methane band and the 6000-A continuum, and ground-based 8900-A methane band images. The VCS of the equatorial plumes is found to be consistent with the hypothesis that the plumes are caused by upwelling at the ammonia condensation level produced by buoyancy due to latent heat release from the condensation of water clouds nearly three scale heights below the plumes.

  20. 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.

  1. 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.

  2. on Guinea Pig Tracheal Chains

    Directory of Open Access Journals (Sweden)

    Rana Keyhanmanesh

    2013-02-01

    Full Text Available   Objective(s: In regard to the high incidence of asthma and the side-effects of the drugs used, finding novel treatments for this disease is necessary. Our previous studies demonstrated the preventive effect of Nigella sativa extract on ovalbumin-induced asthma. In addition, water-soluble substances of N. sativa extract and methanol fraction of this plant were responsible for the relaxant effect of this plant on tracheal chains of guinea pigs. Therefore, for the first time, in the present study, in order to identify main constituents of the methanolic extract, the relaxant effects of five different methanolic fractions (20%, 40%, 60%, 80%, and 100% of N. sativa   on tracheal chains of guinea pigs were examined.     Materials and Methods:     The relaxant effects of four cumulative concentrations of each fraction (0.8, 1.2, 1.6, and 2.0 g% in comparison with saline as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6, and 0.8 mM were examined by their relaxant effects on precontracted tracheal chains of guinea pig by 60 mM KCl (group 1 and 10 μM methacholine (group 2.     Results: In group 1, all concentrations of only theophylline showed significant relaxant effects but all concentrations of these methanolic fractions showed significant contractile effects compared with that of saline (P

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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... Standard Procedures § 113.38 Guinea pig safety test. The guinea pig safety test provided in this section... be injected either intramuscularly or subcutaneously into each of two guinea pigs and the...

  10. 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

  11. 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...

  12. 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)

  13. 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)

  14. 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...

  15. Rapid Calculation of Equatorial Rotation Curves

    OpenAIRE

    Kochanek, C. S.

    2001-01-01

    We derive a simple, fast one-dimensional integral for the equatorial rotation curve of a thin disk with surface density Sigma(R) modeled as a spheroid with axis ratio q. The result is simpler than standard expressions even in the limit of an infinitely thin disk (q-->0).

  16. 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

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

    OpenAIRE

    Fukao, S.; Yokoyama, T; T. Tayama; Yamamoto, M.; Maruyama, T.; Saito, S.

    2006-01-01

    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 obs...

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

    OpenAIRE

    Fukao, S.; Yokoyama, T; T. Tayama; Yamamoto, M.; Maruyama, T.; Saito, S.

    2006-01-01

    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 t...

  19. null Lamington, Papua New Guinea Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dormant stratovolcano in Papua New Guinea suddenly exploded in 1951. Nu?es ardentes (glowing avalanches) shot down the mountain at 100 km per hour, devastated...

  20. 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...

  1. Severe allergic reactions to guinea pig

    OpenAIRE

    Shaw Jeffrey L; Levy Michael B; Zacharisen Michael C; Kurup Viswanath P

    2005-01-01

    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 ...

  2. 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...

  3. 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).

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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...

  9. 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.

  10. 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)

  11. Gravity Wave Seeding of Equatorial Plasma Bubbles

    Science.gov (United States)

    Singh, Sardul; Johnson, F. S.; Power, R. A.

    1997-01-01

    Some examples from the Atmosphere Explorer E data showing plasma bubble development from wavy ion density structures in the bottomside F layer are described. The wavy structures mostly had east-west wavelengths of 150-800 km, in one example it was about 3000 km. The ionization troughs in the wavy structures later broke up into either a multiple-bubble patch or a single bubble, depending upon whether, in the precursor wavy structure, shorter wavelengths were superimposed on the larger scale wavelengths. In the multiple bubble patches, intrabubble spacings vaned from 55 km to 140 km. In a fully developed equatorial spread F case, east-west wavelengths from 690 km down to about 0.5 km were present simultaneously. The spacings between bubble patches or between bubbles in a patch appear to be determined by the wavelengths present in the precursor wave structure. In some cases, deeper bubbles developed on the western edge of a bubble patch, suggesting an east-west asymmetry. Simultaneous horizontal neutral wind measurements showed wavelike perturbations that were closely associated with perturbations in the plasma horizontal drift velocity. We argue that the wave structures observed here that served as the initial seed ion density perturbations were caused by gravity waves, strengthening the view that gravity waves seed equatorial spread F irregularities.

  12. 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.

  13. Equatorial circulation and EUC variability during TACE

    Science.gov (United States)

    Brandt, P.; Hormann, V.; Fischer, J.; Bourlès, B.; Funk, A.

    2009-04-01

    The Tropical Atlantic Climate Experiment (TACE) envisioned by Fritz Schott and coauthors in their white paper represents a focused observational and modeling effort to enhance our understanding of Tropical Atlantic Climate Variability. During recent years, intense shipboard and moored observations were carried out within different national and international initiatives contributing to TACE. The current availability of a large number of cross-equatorial ship sections allows quantifying the mean flow structure in the equatorial Atlantic. Using these shipboard sections a mean westward weakening of the EUC and a westward strengthening of the SEUC from the western boundary toward the central Atlantic were found suggesting substantial recirculations between eastward and westward current bands. Such recirculations are confirmed by subsurface float trajectories. Velocity data from moored Acoustic Doppler current profilers that are deployed on the equator at 23°W between December 2001 and December 2002 as well as between February 2004 and February 2008 allow addressing the seasonal to interannual variability of the flow field along the equator. During the last mooring period from July 2006 to February 2008 additional moorings at 0.75°S and N were successfully deployed. The interannual EUC variability is discussed with respect to the interannual boreal summer cold tongue variability showing substantial variations of the sea surface temperature during recent years.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Food Security Strategies for Papua New Guinea

    OpenAIRE

    Igua, Passinghan Bukley K.

    2001-01-01

    This paper analyzes food availability and its related risks, distribution institutions, uses, commodity balance, food aid and related government policies at the national level. It also looks at household food availability, access, consumption patterns, nutritional quality and sufficiency. The Papua New Guinea National Food Security Policy is also described with its strategies to improve food security in the country.

  20. 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

  1. Hantavirus in African Wood Mouse, Guinea

    OpenAIRE

    Klempa, Boris; Fichet-Calvet, Elisabeth; Lecompte, Emilie; Auste, Brita; Aniskin, Vladimir; Meisel, Helga; Denys, Christiane; Koivogui, Lamine; ter Meulen, Jan; Krüger, Detlev H.

    2006-01-01

    Hantaviruses are rodentborne, emerging viruses that cause life-threatening human diseases in Eurasia and the Americas. We detected hantavirus genome sequences in an African wood mouse (Hylomyscus simus) captured in Sangassou, Guinea. Sequence and phylogenetic analyses of the genetic material demonstrate a novel hantavirus species, which we propose to name "Sangassou virus."

  2. The equatorial electrojet during geomagnetic storms and substorms

    Science.gov (United States)

    Yamazaki, Yosuke; Kosch, Michael J.

    2015-03-01

    The climatology of the equatorial electrojet during periods of enhanced geomagnetic activity is examined using long-term records of ground-based magnetometers in the Indian and Peruvian regions. Equatorial electrojet perturbations due to geomagnetic storms and substorms are evaluated using the disturbance storm time (Dst) index and auroral electrojet (AE) index, respectively. The response of the equatorial electrojet to rapid changes in the AE index indicates effects of both prompt penetration electric field and disturbance dynamo electric field, consistent with previous studies based on F region equatorial vertical plasma drift measurements at Jicamarca. The average response of the equatorial electrojet to geomagnetic storms (Dststorm" effect is found to depend on the magnitude of the storm, solar EUV activity, season, and longitude.

  3. 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.

  4. Interior models of Mercury with equatorial ellipticity

    Science.gov (United States)

    Dumberry, M.

    2012-09-01

    The combination of planetary rotation observations and gravity field measurements by the MESSENGER spacecraft can be used to constrain the internal structure of Mercury. A recently published model suggests a mean mantle density of ρm = 3650 ± 225 kg m-3, substantially larger than that expected of a silicate mantle (3300 kg m-3) and possibly hinting at the presence of an FeS-rich layer at the base of the mantle. Here, we show that a large ρm is only required if the core-mantle boundary (CMB) of the planet is assumed axially-symmetric. An equatorial ellipticity of CMB of the order of 2 · 10-5 allows to satisfy gravity and rotation constraints with a mean mantle density typical of silicate material. Possible origin of such topography include past mantle convection, aspherical planetary shrinking, remnant tidal deformation, or a combination thereof.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. Tropospheric ozone over Equatorial Africa: regional aspects from the MOZAIC data

    Directory of Open Access Journals (Sweden)

    B. Sauvage

    2004-06-01

    Full Text Available We analyze MOZAIC ozone observations recorded over Equatorial Africa, from April 1997 to March 2003 to give the first ozone climatology of this region. The monthly mean vertical profiles have been systematically analyzed with monthly mean ECMWF data using a Lagrangian-model (LAGRANTO. We assess the roles played by the dynamical features of Equatorial Africa and the intense biomass burning sources within the region in defining the ozone distribution. The lower troposphere exhibits layers of enhanced ozone during the biomass burning season in each hemisphere (boreal winter in the northern tropics and boreal summer in the southern tropics. The monthly mean vertical profiles of ozone are clearly influenced by the local dynamical situation. Over the Gulf of Guinea during boreal winter, the ozone profile is characterized by systematically high ozone below 650 hPa. This is due to the high stability caused by the Harmattan winds in the lower troposphere and the blocking Saharan anticyclone in the middle troposphere that prevents any efficient vertical mixing. In contrast, Central African enhancements are not only found in the lower troposphere but throughout the troposphere. The boreal summer ozone maximum in the lower troposphere of Central Africa continues up to November in the middle troposphere due to the influx of air masses laden with biomass burning products from Brazil and Southern Africa. Despite its southern latitude, Central Africa during the boreal winter is also under the influence of the northern tropical fires. This phenomenon is known as the "ozone paradox". However, the tropospheric ozone columns calculated from the MOZAIC data give evidence that the Tropical Tropospheric Ozone Column (TTOC maximum over Africa swings from West Africa in DJF to Central Africa in JJA. This contrasts with studies based on TOMS satellite data. A rough assessment of the regional ozone budget shows that the northern tropics fires in boreal winter might

  10. 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)

  11. Proton flux under radiation belts: near-equatorial zone

    International Nuclear Information System (INIS)

    In this work the features of low-energy proton flux increases in near-equatorial region (McIlvein parameter Lth the proton flux (with energy from tens keV up to several MeV) increases are registering regularly. However modern proton flux models (for example AP8 model) works at L>1.15 only and does not take into account near-equatorial protons. These fluxes are not too big, but the investigation of this phenomenon is important in scope of atmosphere-ionosphere connections and mechanisms of particles transport in magnetosphere. In according to double charge-exchange model the proton flux in near-equatorial region does not depend on geomagnetic local time (MLT) and longitude. However the Azur satellite data and Kosmos-484, MIR station and Active satellite data revealed the proton flux dependence on longitude. The other feature of near-equatorial proton flux is the dependence on geomagnetic local time revealed in the Sampex satellite experiment and other experiments listed above. In this work the dependences on MLT and longitude are investigated using the Active satellite (30-500 keV) and Sampex satellite (>800 keV). This data confirms that main sources of near-equatorial protons are radiation belts and ring current. The other result is that near-equatorial protons are quasi-trapped. The empirical proton flux dependences on L, B at near-equatorial longitudes are presented. (author)

  12. 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.

  13. 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.

  14. Filial Attachment and its Disruption: Insights from the Guinea Pig

    OpenAIRE

    Hennessy, Michael B.

    2014-01-01

    Guinea pigs are precocial rodents that show evidence of a selective attachment to the mother who, in turn, exhibits little active maternal care. Effects of separation in guinea pigs are, therefore, more likely to reflect the disruption of attachment than the removal of, or alterations in, patterns of maternal care. Here, effects in guinea pigs of the presence or absence of the mother on psychobiological endpoints and of maternal separation on depressive-like behavior are reviewed. It is argue...

  15. 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.

  16. The injury mortality burden in Guinea

    Directory of Open Access Journals (Sweden)

    Mamady Keita

    2012-09-01

    Full Text Available Abstract Background The injury mortality burden of Guinea has been rarely addressed. The paper aimed to report patterns of injury mortality burden in Guinea. Methods We retrieved the mortality data from the Guinean Annual Health Statistics Report 2007. The information about underlying cause of deaths was collected based on Guinean hospital discharge data, Hospital Mortuary and City Council Mortuary data. The causes of death are coded in the 9th International Classification of Diseases (ICD-9. Multivariate Poisson regression was used to test the impacts of sex and age on mortality rates. The statistical analyses were performed using Statatm 10.0. Results In 2007, 7066 persons were reported dying of injuries in Guinea (mortality: 72.8 per 100,000 population. Transportation, fire/burn, falls, homicide and drowning were the five leading causes of fatal injuries for the whole population, accounting for 37%, 22%, 12%, 10% and 6% of total deaths, respectively. In general, age-specific injury causes displayed similar patterns of the whole population except that poisoning replaced falls as a leading cause among children under five years old. Males were at 30-50% more risk of dying from six commonest causes than females and old age groups had higher injury mortality rates than younger age groups. Conclusion Transportation, fire/burn, falls, homicide, and drowning accounted for the majority of total injury mortality burden in Guinea. Males and old adults were high-risk population of fatal injuries and should be targeted by injury prevention. Lots of work is needed to improve weak capacities for injury control in order to reduce the injury mortality burden.

  17. 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

  18. Methods for Cryopreservation of Guinea Fowl Sperm

    OpenAIRE

    Váradi, Éva; Végi, Barbara; Liptói, Krisztina; Barna, Judit

    2013-01-01

    Conservation of indigenous poultry species is an important part of the new Hungarian agricultural strategy. Semen cryopreservation is the most practical method for the long term storage of poultry genetic material. The objective was to compare four protocols for cryopreservation of guinea fowl sperm (slow and fast programmable, freezing in nitrogen vapor, and pellet) and three cryoprotectants (10% ethylene glycol, 6% dimethyl-formamide and 6% dimethyl-acetamide). The efficiency of the methods...

  19. 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

  20. 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...

  1. Sexing in guinea fowls (Numida meleagris).

    Science.gov (United States)

    Abdul-Rahman, Iddriss I; Awumbila, Bawa; Jeffcoate, Ian A; Robinson, Jane E; Obese, Frederick Y

    2015-02-01

    Despite the potentials and contributions of guinea fowls to economic and social life in Ghana, accurate sex identification in these birds is still a major problem. Three hundred and sixty guinea fowls (180 birds per sex) were used in determining a more accurate and farmer friendly sexing technique. The sexing methods explored were vent, biometric, and molecular techniques. Vent sexing was accomplished by measuring phalli in 28 and 32-week-old birds, while biometric sexing involved the measurement of morphometric traits and data analyzed using discriminant function analysis. Molecular sexing was carried out by DNA extraction and subsequent PCR using the 2550F/2718R primer set. Females had a wider (PPhallus size in the 2 sexes were distinguishable from 8 weeks of age, with males having longer and thicker (P<0.05) phalli than their female counterparts. Combining the 2 variables in a discriminate function, males and females could be distinguished with 98.3% accuracy. While the molecular method remains the most accurate sexing technique, the biometric method emerged as the most farmer friendly approach to sexing guinea fowls. PMID:25595479

  2. Equatorial airglow depletions induced by thermospheric winds

    Energy Technology Data Exchange (ETDEWEB)

    Meriwether J.W. Jr.; Biondi, M.A.; Anderson, D.N.

    1985-08-01

    Interferometric observations of the 630.0 nm nightglow brightness at the equatorial station of Arequipa. Peru (16.2/sup 0/S, 71.4/sup 0/W geographic, 3.2/sup 0/S dip latitude) have revealed widespread areas of airglow depletion, with reductions in intensity as large as factors of 3 or 4. These depletions correlated closely with large increases of the equatorward (northward) wind and the 630.0 nm kinetic temperature. On occasion, the usually small meridonal wind reached a velocity of 100 m/s near 22/sup h/ LT lasting for 1 or 2 hours. The temperature increases of 10 K or more existed only in the poleward (southward) direction. Comparisons with modeling calculations suggest that this effect results from an upward movement of the ionosphere along the inclined magnetic field lines, driven by the equatorward neutral wind. The airglow column integrated emission rate is consequently decreased by the slower rate of formation and subsequent dissociative recombination of molecular oxygen ions within the higher F-layer. We conclude that the transient period of equatorward wind is a result of the passage of the midnight pressure bulge.

  3. Equatorial airglow depletions induced by thermospheric winds

    Energy Technology Data Exchange (ETDEWEB)

    Meriwether, J.W.; Biondi, M.A.; Anderson, D.N.

    1985-08-01

    Interferometric observations on the 630.0 nm nightglow brightness at the equatorial station at Arequipa, Peru (16.2 S, 71.4 W geographic, 3.2 S dip latitude) have revealed widespread areas of airglow depletion, with reductions in intensity as large as factors of 3 or 4. These depletions correlated closely with large increases of the equatorward (northward) wind and the 630.0 nm kinetic temperature. On occasion, the usually small meridional wind reached a velocity of 100 m/s near 22h LT lasting for 1 to 2 hours. The temperature increases of 100K or more existed only in the poleware (southward) direction. Comparisons with modeling calculations suggest that this effect results from an upward movement of the ionosphere along the inclined magnetic field lines, driven by the equatorward neutral wind. The airglow column integrated emission rate is consequently decreased by the slower rate of formation and subsequent dissociative recombination of molecular oxygen ions within the higher F-layer. We conclude that the transient period of equatorward wind is a result of the passage of the midnight pressure bulge. (Author)

  4. 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.

  5. Plasma turbulence in the equatorial electrojet

    International Nuclear Information System (INIS)

    Plasma turbulence in the daytime and nighttime equatorial electrojet is studied with a highly sophisticated radar interferometer technique. It is shown that the outer scale of the plasma turbulence scales with the zero order plasma density gradient length, and is smaller during the day because of increased recombinational damping. Observations indicate that the horizontally propagating coherent waves at the other scale dominate the electrojet turbulence and give rise to vertically propagating type 1 waves during strong electrojet conditions. According to the linear theory extended to the long wavelength regime the large scale primary modes are dispersive and have phase velocities considerably smaller than the mean driving electron velocity, in agreement with the interferometer observations. Vertical electron transport, a quasi-linear effect due to large scale wave action, is shown to give rise to a vertical dc current which has the right direction and magnitude to explain the up-down and possibly the east-west asymmetries observed at Jicamarca. These quasi-linear considerations also show that the first order perturbed vertical electron velocity associated with the primary mode is limited to a maximum value on the order of the mean horizontal electron velocity, which might explain why vertically propagating type 1 waves are only observed during strong electrojet conditions

  6. Catastrophic ape decline in western equatorial Africa.

    Science.gov (United States)

    Walsh, Peter D; Abernethy, Kate A; Bermejo, Magdalena; Beyers, Rene; De Wachter, Pauwel; Akou, Marc Ella; Huijbregts, Bas; Mambounga, Daniel Idiata; Toham, Andre Kamdem; Kilbourn, Annelisa M; Lahm, Sally A; Latour, Stefanie; Maisels, Fiona; Mbina, Christian; Mihindou, Yves; Obiang, Sosthène Ndong; Effa, Ernestine Ntsame; Starkey, Malcolm P; Telfer, Paul; Thibault, Marc; Tutin, Caroline E G; White, Lee J T; Wilkie, David S

    2003-04-10

    Because rapidly expanding human populations have devastated gorilla (Gorilla gorilla) and common chimpanzee (Pan troglodytes) habitats in East and West Africa, the relatively intact forests of western equatorial Africa have been viewed as the last stronghold of African apes. Gabon and the Republic of Congo alone are thought to hold roughly 80% of the world's gorillas and most of the common chimpanzees. Here we present survey results conservatively indicating that ape populations in Gabon declined by more than half between 1983 and 2000. The primary cause of the decline in ape numbers during this period was commercial hunting, facilitated by the rapid expansion of mechanized logging. Furthermore, Ebola haemorrhagic fever is currently spreading through ape populations in Gabon and Congo and now rivals hunting as a threat to apes. Gorillas and common chimpanzees should be elevated immediately to 'critically endangered' status. Without aggressive investments in law enforcement, protected area management and Ebola prevention, the next decade will see our closest relatives pushed to the brink of extinction. PMID:12679788

  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. ITER L 6 equatorial maintenance duct remote handling study

    International Nuclear Information System (INIS)

    The status and conclusions of a preliminary study of equatorial maintenance duct remote handling is reported. Due to issues with the original duct design a significant portion of the study had to be refocused on equatorial duct layout studies. The study gives an overview of some of the options for design of these ducts and the impact of the design on the equipment to work in the duct. To develop a remote handling concept for creating access through the ducts the following design tasks should be performed: define the operations sequences for equatorial maintenance duct opening and closing; review the remote handling requirements for equatorial maintenance duct opening and closing; design concept for door and pipe handling equipment and to propose preliminary procedures for material handling outsides the duct. 35 figs

  10. Climate Prediction Center Equatorial Southern Oscillation Index (1949-present)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is one of the CPC?s Monthly Atmospheric and SST Indices. It contains Equatorial Southern Oscillation Index (standardized sea level pressure differences between...

  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. 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.

  13. 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.

  14. Atlantic Equatorial Deep Jets: Space–Time Structure and Cross-Equatorial Fluxes

    OpenAIRE

    Send, Uwe; Eden, Carsten; Schott, Friedrich

    2002-01-01

    The so-called equatorial stacked jets are analyzed with ship-board observations and moored time series from the Atlantic Ocean. The features are identified and isolated by comparing vertical wavenumber spectra at the equator with those a few degrees from the equator. Mode-filtering gives clear views of the jets in meridional sections, the typical extent being ±1° in latitude. The vertical structure can be well described (explaining 82% of the variance) by N−1-stretched cosines, with a Gaussia...

  15. 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.

  16. 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.

  17. EQUATORIAL ZONAL JETS AND JUPITER's GRAVITY

    International Nuclear Information System (INIS)

    The depth of penetration of Jupiter's zonal winds into the planet's interior is unknown. A possible way to determine the depth is to measure the effects of the winds on the planet's high-order zonal gravitational coefficients, a task to be undertaken by the Juno spacecraft. It is shown here that the equatorial winds alone largely determine these coefficients which are nearly independent of the depth of the non-equatorial winds

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

    Science.gov (United States)

    Fukao, S.; Yokoyama, T.; Tayama, T.; Yamamoto, M.; Maruyama, T.; Saito, S.

    2006-07-01

    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.

  1. 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

  2. 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…

  3. 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

  4. 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

  5. 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…

  6. 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

  7. Vestido, identidad y folklore. La invención de un vestido nacional de Guinea Ecuatorial

    Directory of Open Access Journals (Sweden)

    Valenciano-Mañé, Alba

    2012-06-01

    Full Text Available Focussing on clothing viewed as a body practice, this paper attempts to provide an ethnographic overview through the examination of the creation of the national dress of Equatorial Guinea. With a discussion of the importance of the personal motivation of its promoters, the reasons for its alleged failure and the recent attempts in current fashion shows in Malabo to (reproduce identity discourses, this paper also seeks to demonstrate the capacity of dress as a tool for social control, resistance and identity (recreation.

    Situando el vestido como práctica corporal en el centro de la reflexión, el artículo efectúa un recorrido etnográfico por el proceso de creación de un vestido nacional de Guinea Ecuatorial. Se presentará la importancia de la ecuación personal de sus impulsores, los motivos de su fracaso y las recientes tentativas de (reproducción de discursos identitarios en los actuales fashion shows de Malabo. De este modo, se pretende demostrar el potencial del vestido como herramienta de control social, resistencia y (recreación identitaria.

  8. Schistosoma mansoni: the cutaneous response to cercarial challenge in naive guinea pigs and guinea pigs vaccinated with highly irradiated cercariae

    International Nuclear Information System (INIS)

    Naive guinea pigs and guinea pigs vaccinated 4 weeks previously with highly irradiated cercariae were challenged percutaneously with normal cercariae. Skin samples from the challenge site were then harvested at varying times to provide histological, quantitative and ultrastructural data on the respective cellular responses to cercarial invasion. (author)

  9. Schistosoma mansoni: the cutaneous response to cercarial challenge in naive guinea pigs and guinea pigs vaccinated with highly irradiated cercariae

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, E.J.; McLaren, D.J.

    1986-10-01

    Naive guinea pigs and guinea pigs vaccinated 4 weeks previously with highly irradiated cercariae were challenged percutaneously with normal cercariae. Skin samples from the challenge site were then harvested at varying times to provide histological, quantitative and ultrastructural data on the respective cellular responses to cercarial invasion.

  10. Tracheobronchial clearance studies in the guinea pig

    International Nuclear Information System (INIS)

    Tracheobronchial clearance in guinea pigs exposed to relatively monodisperse aerosols was studied. Two new techniques were developed which enabled tagging of polystyrene particles with 198Au and with a fluorescent dye. A procedure was also developed to generate polystyrene particles with a vibrating orifice generator. Seventy animals were exposed via inhalation to relatively monodisperse polystyrene aerosols. Following exposure, animals were radioactively counted at regular intervals, sacrificed at predetermined times, and the lungs were removed, inflated to a standard pressure, frozen in liquid nitrogen, and freeze-dried. The freeze-dried lungs were sectioned completely, examined with a fluorescent microscope, and measurements were made of airway diameters in which particles were found. The results indicated a significant penetration of particles to the distal bronchioles and air spaces for 7.9 μm (MMD) particles and a lesser, though still significant, penetration for 10.3 μm (MMD) particles. An anatomical model for guinea pig lung morphology was used to classify particular ranges of airway diameters into zones. These zones were used to specify a compartmental model for lung clearance and the experimental particle distributions were categorized using this model. Equations were then developed describing the compartmental clearance. Rate constants were then obtained and used to predict airway transport rates in specific lung generations.The predicted transport rates ranged from approximately 0.001 mm/min in the distal bronchioles to approximately 8 mm/min in the trachea. These values agree with previous models for airway transport rates, and are consistent with experimental determinations of tracheal transport rates. Transit times were calculated and the results indicate a 24 hr clearance time for tracheobronchial clearance in the guinea pig

  11. 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...

  12. 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...

  13. 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.

  14. 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 ...

  15. 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.

  16. Meso-Cenozoic Source-to-Sink analysis of the African margin of the Equatorial Atlantic

    Science.gov (United States)

    Chardon, Dominique; Rouby, Delphine; Huyghe, Damien; Ye, Jing; Guillocheau, François; Robin, Cécile; Dall'Asta, Massimo; Brown, Roderick; Webster, David

    2015-04-01

    The Transform Source to Sink Project (TS2P) objective is to link the evolution of the offshore sedimentary basins of the African margin of the Equatorial Atlantic and their source areas on the West African Craton. The margin consists in alternating transform and oblique margin portions from Guinea, in the West, to Nigeria, in the East. Such a longitudinal structural variability is associated with variation in the margin width, continental geology and relief, drainage networks and subsidence/accumulation patterns that we analyzed using offshore seismic data and onshore geology and geomorphology. We compare syn- to post rift offshore geometry and long-term stratigraphic history of each of the margin segments. Transform faults appear to play a major role in shaping Early Cretaceous syn-rift basin architectures. Immediate post-rift Late Cretaceous sedimentary wedges record a transgression and are affected by the reactivation of some of transform faults. We produced A new type of inland paleogeographic maps for key periods since the end of the Triassic, allowing delineation of intracratonic basins having accumulated material issued from erosion of the marginal upwarps that have grown since break-up along the margin. We use offshore and onshore basin analysis to estimate sediment accumulation and integrate it in a source-to-sink analysis where Mesozoic onshore denudation will be estimated by low-temperature thermochronology. Cenozoic erosion and drainage history of the continental domain have been reconstructed from the spatial analysis of dated and regionally correlated geomorphic markers. The stationary drainage configuration of the onshore domain since 30 Ma offers the opportunity to correlate the detailed onshore morphoclimatic record based on the sequence of lateritic paleolandsurfaces to offshore stratigraphy, eustasy and global climatic proxies since the Oligocene. Within this framework, we simulate quantitative solute / solid erosional fluxes based on the

  17. 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)

  18. 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 ...

  19. 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.

  20. Equatorial noise emissions with quasiperiodic modulation of wave intensity

    Czech Academy of Sciences Publication Activity Database

    Němec, F.; Santolík, Ondřej; Hrbáčková, Zuzana; Pickett, J. S.; Cornilleau-Wehrlin, N.

    2015-01-01

    Roč. 120, č. 4 (2015), s. 2649-2661. ISSN 2169-9380 R&D Projects: GA MŠk(CZ) LH11122 Institutional support: RVO:68378289 Keywords : equatorial noise * magnetosonic waves * quasiperiodic modulation Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/2014JA020816/full

  1. Equatorial Noise Emissions and Their Quasi-Periodic Modulation

    Czech Academy of Sciences Publication Activity Database

    Němec, F.; Santolík, Ondřej; Hrbáčková, Zuzana; Pickett, J.; Cornilleau-Wehrlin, N.; Parrot, M.; Hayosh, Mykhaylo

    San Francisco: American Geophysical Union, 2015. SM51F-03. [AGU Fall Meeting 2015. 14.12.2015-18.12.2015, San Francisco] Institutional support: RVO:68378289 Keywords : equatorial noise * magnetosonic waves * quasiperiodic modulation Subject RIV: BL - Plasma and Gas Discharge Physics https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/59251

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

    NARCIS (Netherlands)

    van der Werf, G. R.; Dempewolf, J.; Trigg, S. N.; Randerson, J. T.; Kasibhatla, P. S.; Giglio, L.; Murdiyarso, D.; Peters, W.; Morton, D. C.; Collatz, G. J.; Dolman, A. J.; Defries, R. S.

    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

  3. 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.

  4. 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...

  5. The Spectral Geometry of the Equatorial Podles Sphere

    OpenAIRE

    Dabrowski, Ludwik; Landi, Giovanni; Paschke, Mario; Sitarz, Andrzej

    2004-01-01

    We propose a slight modification of the properties of a spectral geometry a la Connes, which allows for some of the algebraic relations to be satisfied only modulo compact operators. On the equatorial Podles sphere we construct suq2-equivariant Dirac operator and real structure which satisfy these modified properties.

  6. Yanai waves in the western equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterjee, A.; Shankar, D.; McCreary, J.P.; Vinayachandran, P.N.

    Observations and models have shown the presence of intraseasonal fluctuations in 20-30-day and 10-20-day bands in the equatorial Indian Ocean west of 60 degrees E (WEIO). Their spatial and temporal structures characterize them as Yanai waves, which...

  7. 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

  8. Reversing the objective: Adding guinea pig pedagogies

    Science.gov (United States)

    Weinstein, Matthew

    2004-03-01

    This article explores objectification in science and science education, i.e., the way material is turned into an object of interest to scientists. Drawing on sociological and anthropological drama theory, it examines how objectification does and does not occur in classrooms and schools. To understand the role and relationship of the object to the scientist, I look at current literature from the social studies of science concerning human and nonhuman objects as well as my own ethnographic work on the activism of politicized human research subjects. The paper concludes by how and why a more self-conscious focus on the object of science is important for those concerned with equity in science education, suggesting that such guinea pig pedagogies restore missing historical and ethical dimensions to science education.

  9. 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.

  10. 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.

  11. Peat in the mountains of New Guinea

    Directory of Open Access Journals (Sweden)

    G.S. Hope

    2015-11-01

    Full Text Available Peatlands are common in montane areas above 1,000 m in New Guinea and become extensive above 3,000 m in the subalpine zone. In the montane mires, swamp forests and grass or sedge fens predominate on swampy valley bottoms. These mires may be 4–8 m in depth and up to 30,000 years in age. In Papua New Guinea (PNG there is about 2,250 km2 of montane peatland, and Papua Province (the Indonesian western half of the island probably contains much more. Above 3,000 m, peat soils form under blanket bog on slopes as well as on valley floors. Vegetation types include cushion bog, grass bog and sedge fen. Typical peat depths are 0.5‒1 m on slopes, but valley floors and hollows contain up to 10 m of peat. The estimated total extent of mountain peatland is 14,800 km2 with 5,965 km2 in PNG and about 8,800 km2 in Papua Province. The stratigraphy, age structure and vegetation histories of 45 peatland or organic limnic sites above 750 m have been investigated since 1965. These record major vegetation shifts at 28,000, 17,000‒14,000 and 9,000 years ago and a variable history of human disturbance from 14,000 years ago with extensive clearance by the mid-Holocene at some sites. While montane peatlands were important agricultural centres in the Holocene, the introduction of new dryland crops has resulted in the abandonment of some peatlands in the last few centuries. Despite several decades of research, detailed knowledge of the mountain peatlands is poor and this is an obstacle to scientific management.

  12. Guinea-pig productivity under traditional management.

    Science.gov (United States)

    Manjeli, Y; Tchoumboue, J; Njwe, R M; Teguia, A

    1998-04-01

    Results of a 12 month study of traditional guinea-pig production in the western highlands of Cameroon are reported. The mean age of guinea-pigs (Cavia porcellus L.) at first parturition, kidding interval and litter size at birth were 126.30 +/- 10.40 d, 64.8 +/- 1.70 d and 1.63 +/- 0.26 kids respectively. The annual reproductive rate was 9.18 kids/breeding doe while the doe post-partum weight was 530 g. Mean body weights at birth, presumed weaning (21 d) and 15 weeks of age were 78.36 +/- 3.20, 147.51 +/- 8.10 and 418.88 +/- 32 g respectively. Type of birth and sex had a significant effect on body weight at all ages. Birth weight dropped significantly from 83.88 +/- 2.87 g for singles to 81.57 +/- 3.40 g for twins, 74.25 +/- 2.39 g for triplets and 73.75 +/- 4.12 g for quadruplets. These differences were maintained to maturity (15 weeks). Males were generally heavier than females. Mortality rates were relatively high among kids: 24% at birth, 39% at 3 weeks and 40% at 15 weeks. Productivity indices were 0.827 kg of young weaned per doe per year, 1560 g of young weaned per kg of doe per year and 2.52 kg of young weaned per kg metabolic weight (kg 0.75) of female per year. PMID:9719838

  13. Shortage of vaccines during a yellow fever outbreak in Guinea.

    OpenAIRE

    Nathan, N.; Barry, M; Van Herp, Michel; Zeller, H.

    2001-01-01

    A yellow fever epidemic erupted in Guinea in September, 2000. From Sept 4, 2000, to Jan 7, 2001, 688 instances of the disease and 225 deaths were reported. The diagnosis was laboratory confirmed by IgM detection in more than 40 patients. A mass vaccination campaign was limited by insufficient international stocks. After the epidemic in Guinea, the International Coordinating Group on Vaccine Provision for Epidemic Meningitis Control decided that 2 million doses of 17D yellow fever vaccine, bei...

  14. 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...

  15. Lagrangian mixed layer modeling of the western equatorial Pacific

    Science.gov (United States)

    Shinoda, Toshiaki; Lukas, Roger

    1995-01-01

    Processes that control the upper ocean thermohaline structure in the western equatorial Pacific are examined using a Lagrangian mixed layer model. The one-dimensional bulk mixed layer model of Garwood (1977) is integrated along the trajectories derived from a nonlinear 1 1/2 layer reduced gravity model forced with actual wind fields. The Global Precipitation Climatology Project (GPCP) data are used to estimate surface freshwater fluxes for the mixed layer model. The wind stress data which forced the 1 1/2 layer model are used for the mixed layer model. The model was run for the period 1987-1988. This simple model is able to simulate the isothermal layer below the mixed layer in the western Pacific warm pool and its variation. The subduction mechanism hypothesized by Lukas and Lindstrom (1991) is evident in the model results. During periods of strong South Equatorial Current, the warm and salty mixed layer waters in the central Pacific are subducted below the fresh shallow mixed layer in the western Pacific. However, this subduction mechanism is not evident when upwelling Rossby waves reach the western equatorial Pacific or when a prominent deepening of the mixed layer occurs in the western equatorial Pacific or when a prominent deepening of the mixed layer occurs in the western equatorial Pacific due to episodes of strong wind and light precipitation associated with the El Nino-Southern Oscillation. Comparison of the results between the Lagrangian mixed layer model and a locally forced Eulerian mixed layer model indicated that horizontal advection of salty waters from the central Pacific strongly affects the upper ocean salinity variation in the western Pacific, and that this advection is necessary to maintain the upper ocean thermohaline structure in this region.

  16. 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.

  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. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Occurrence of equatorial spread F during intense geomagnetic storms

    Science.gov (United States)

    Ray, S.; Roy, B.; Das, A.

    2015-07-01

    Equatorial spread F (ESF) has been observed in response to the prompt penetration of magnetospheric electric field to equatorial latitudes during intense (minimum Dst ≤ -100 nT; Bz ≤ -10 nT for at least 3 h) magnetic storms using global ion density plots of Defense Meteorological Satellite Program (DMSP) over nearly one solar cycle (1996-2005). Geostationary amplitude scintillation observations from Calcutta at VHF and L band for 1996-2005 and GPS amplitude scintillation measurements during 2004-2005 from the Indian Satellite Based Augmentation System Geostationary and GPS Navigation Outlay (GPS Aided GEO Augmented Navigation) network of stations all over India have been used to corroborate the DMSP observations. Subsequent to the time of southward interplanetary magnetic field Bz crossing -10 nT for an intense storm, it has been observed that within 4 h, ESF is generated at a longitude where the local time is dusk.

  7. 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.

  8. 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.

  9. 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.

  10. Neutronics for equatorial and upper ports in ITER

    International Nuclear Information System (INIS)

    Highlights: • ITER neutronics calculations for Diagnostic Equatorial Port Plug (EPP) and Electron Cyclotron Heating Upper Launcher (ECHUL). • Activation and radiation shielding calculations have been performed using the MCNP5, FISPACT-2007, and R2Smesh codes. • Dominant effect of radiation streaming along the port plug gaps was recognized. • An optimized double labyrinth was recommended for the current EPP design. • Neutronics modelling assumptions significantly affect fluxes and doses inside the ITER port interspaces. -- Abstract: Specific neutronics features of the ITER equatorial and upper ports are discussed in this paper as related to the design development of Diagnostic Equatorial Port Plug (EPP) and Electron Cyclotron Heating Upper Launcher (ECHUL). The focus is on the EPP analysis. Neutronics analyses are based on new calculation results of neutron/photon fluxes, nuclear heating, neutron damage and shutdown dose rates. The results were obtained with the radiation transport code MCNP5, the activation code FISPACT-2007, and the Rigorous 2 Step mesh-based (R2Smesh) interface code which allows to provide shutdown dose rate distributions with high spatial resolution. It was revealed that neutron flux levels in the port access areas, the resulting activation of the port materials and the equivalent radiation doses imposed to work personnel after ITER shutdown are strongly dependent on the openings in the port shielding blocks. For the ECHUL in the upper port, neutron fluxes have been calculated for an updated ITER model and compared with previous results. This work reveals substantial radiation cross-talk effects between the lower, the equatorial and the upper ITER ports and provides fundamental results which can be utilized for further investigations of suitable design options of ITER ports

  11. 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.

  12. 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...

  13. Equatorial Superrotation on Earth Induced by Optically Thick Dust Clouds

    Science.gov (United States)

    Zhu, X.; Oman, L. D.; Waugh, D. W.; Lloyd, S. A.

    2008-12-01

    How does the Earth's atmosphere respond to exceptional aerosol events, and what is the mechanism leading to consequent past and possible future climate shifts? One possible mechanism leading to aerosol-induced climate shifts is the striking atmospheric dynamics phenomenon of equatorial superrotation, such as that found on Venus and Saturn's moon Titan, with its enhanced meridional transport. Recently, a significant breakthrough has been made in our theoretical understanding of atmospheric superrotation on Venus and Titan. Extending this result regarding superrotation in planetary atmospheres to the concept of superrotation in Earth's atmosphere serves not only to shed insight into long-standing and seemingly disparate questions of Earth's climate (such as the mechanism of mass extinction and geo-engineering mitigation of global warming) but also to develop a common theoretical framework to address the impacts of profound changes of atmospheric aerosols and their consequences. The three-dimensional Goddard Institute for Space Studies (GISS) modelE GCM and Johns Hopkins University Applied Physics Laboratory (JHU/APL) two-dimensional radiative-dynamical model are used to investigate the induction of equatorial superrotation in Earth's stratosphere, as well as its effect on meridional transport of dust and aerosols in association with the supervolcano eruptions. Preliminary results show that an equatorial superrotational wind in the upper troposphere was initiated and lasted for more than two years following the Mt Toba eruption near the equator about 71,000 years ago. The circulation structure at mid-latitude was also altered, indicating a global impact of an equatorial injection of an aerosol layer.

  14. 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 ...

  15. 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...

  16. Air-Sea Coupling Over The Equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Gopika, N.

    subcontinent and adjoining areas of Southeast Asia. Recurrence of these summer monsoon rains is critical to agricultural production that provides life-sustaining support for a billion people in the region. The reversing monsoon winds also generate a unique... with latitude makes the equatorial areas a special region. This makes the equator as a wave-guide within which the signal of atmospheric forcing could be transferred over long distances without much energy loss. For 13 example, the zonal momentum...

  17. 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.

  18. Impacts of the Atlantic Equatorial Mode in a warmer climate

    Science.gov (United States)

    Mohino, Elsa; Losada, Teresa

    2015-10-01

    The main source of sea surface temperature (SST) variability in the Tropical Atlantic at interannual time scales is the Equatorial Mode or Atlantic El Niño. It has been shown to affect the adjacent continents and also remote regions, leading to a weakened Indian Monsoon and promoting La Niña-type anomalies over the Pacific. However, its effects in a warmer climate are unknown. This work analyses the impact of the Equatorial Mode at the end of the twenty first century by means of sensitivity experiments with an atmosphere general circulation model. The prescribed boundary conditions for the future climate are based on the outputs from models participating in the coupled model intercomparison project—phase V. Our results suggest that even if the characteristics of the Equatorial Mode at the end of the twenty first century remained equal to those of the twentieth century, there will be an eastward shift of the main rainfall positive anomalies in the Tropical Atlantic and a weakening of the negative rainfall anomalies over the Asian monsoon due to the change in climatological SSTs. We also show that extratropical surface temperature anomalies over land related to the mode will change in regions like Southwestern Europe, East Australia, Asia or North America due to the eastward shift of the sea level pressure systems and related surface winds.

  19. Deep-sea habitat heterogeneity influence on meiofaunal communities in the Gulf of Guinea

    Science.gov (United States)

    Van Gaever, Saskia; Galéron, Joëlle; Sibuet, Myriam; Vanreusel, Ann

    2009-12-01

    To estimate the degree of spatial heterogeneity of benthic deep-sea communities, we carried out a multiple-scale (from m's to 200 km) investigation in the Congo-Angola margins (Equatorial West African margin, 3150-4800 m) in which we examined the metazoan meiofauna at a variety of habitats along the Congo Channel system and in the associated cold seep. We investigate the structure, density, vertical distribution patterns in the sediment and biomass of meiofaunal communities in the Gulf of Guinea and how they are controlled by hydrologic and biogeochemical processes. The meiofaunal communities in the Gulf of Guinea were shaped by heterogeneous conditions on the margin, and reflect the multiple-scale spatial variability that corresponds with the different identified habitats. The two control sites, located at >100 km away from the canyon, were inhabited by very dense and the most diverse meiobenthic communities. Similar meiobenthic communities inhabited the transition zone between the canyon and the cold seep. Sites located along the Congo Channel were obviously affected by the local high-velocity bottom currents and unstable sedimentary conditions in this active submarine system. Extremely low meiobenthic densities and very low proportions in the most surficial sediment layers provided evidence for recently highly disturbed sediments at these sites. The remote operated vehicle (ROV) Victor 6000 provided images of the cold seep, showing a patchy distribution of several types of patchy distributed megafaunal communities dominated by three key symbiotic taxa (Mytilidae, Vesicomyidae and Siboglinidae). These cold seep sediments were colonised by a unique meiobenthic community, characterised by a high small-scale (m's) patchiness, low species richness and the prominent dominance of two large-sized nematode species: Sabatieria mortenseni, which is a cosmopolitan nematode known from littoral habitats, and an undescribed Desmodora species. The high individual body weight of

  20. Radiation induced micrencephaly in guinea pigs

    International Nuclear Information System (INIS)

    A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with the findings of small head size induced in those exposed prior to the eight week of conception at Hiroshima. This implies a mechanism for micrencephaly different from those previously suggested and lends credence to a causal relation between radiation and small head size in humans at low doses as reported by Miller and Mulvihill. 16 refs., 13 tabs

  1. Equatorial scintillations in relation to the development of ionization anomaly

    Directory of Open Access Journals (Sweden)

    S. Ray

    2006-07-01

    Full Text Available The irregularities in the electron density distribution of the ionosphere over the equatorial region frequently disrupt space-based communication and navigation links by causing severe amplitude and phase scintillations of signals. Development of a specification and forecast system for scintillations is needed in view of the increased reliance on space-based communication and navigation systems, which are vulnerable to ionospheric scintillations. It has been suggested in recent years that a developed equatorial anomaly in the afternoon hours, with a steep gradient of the F-region ionization or Total Electron Content (TEC in the region between the crest and the trough, may be taken as a precursor to scintillations on transionospheric links. Latitudinal gradient of TEC measured using Faraday Rotation technique from LEO NOAA 12/14 transmissions during the afternoon hours at Calcutta shows a highly significant association with L-band scintillations recorded on the INMARSAT link, also from Calcutta, during the equinoxes, August through October 2000, and February through April 2001.

    The daytime equatorial electrojet is believed to control the development of the equatorial anomaly and plays a crucial role in the subsequent development of F-region irregularities in the post-sunset hours. The diurnal maximum and integrated value (integrated from the time of onset of plasma influx to off-equatorial latitudes till local sunset of the strength of the electrojet in the Indian longitude sector shows a significant association with post-sunset L-band scintillations recorded at Calcutta during the two equinoxes mentioned earlier.

    Generation of equatorial irregularities over the magnetic equator in the post-sunset hours is intimately related to the variation of the height of the F-layer around sunset. Ionosonde data from Kodaikanal, a station situated close to the magnetic equator, has been utilized

  2. 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

  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. Honey and honey bees of Guinea-Bissau

    OpenAIRE

    Pinto, M. Alice; Batista, Vânia; Alves, Dulce; Vilas-Boas, Miguel

    2011-01-01

    Beekeeping is an ancient activity in Guinea-Bissau. The ancestral interaction with bees stands on “honey hunting” of natural colonies or use of traditional hives hanged on trees. These hives are perfect shelters for swarms but the colony is destroyed every year after honey harvesting. Bees are therefore kept as wild as ever with little, if any, interference from man. Reports on honey bees and honey of Guinea-Bissau are scarce. Herein we report the first data on honey quality and provide a...

  5. 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...

  6. Regeneration of guinea PIG facial nerve: the effect of hypergravity

    Science.gov (United States)

    Rosenzweig, E.; Horodiceanu, E.; Ishay, J. S.

    Exposure to moderate hypergravity improves the regenerative capacity of sectioned guinea-pig facial nerve. The improvement in regeneration is tri-directional as follows: a) an average 1.7 fold increase in rate of regeneration in guinea pigs subjected to hypergravity; b) a 25% enhancement of facial muscle activity following the exposure to hypergravity; and c) improvement in the quality of regeneration from an esthetic standpoint. A good correlation was recorded between the histological structure of the severed nerve at the end of the regeneration and the clinical results.

  7. 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

  8. 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.

  9. 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.

  10. 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 ...

  11. 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.

  12. 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)

  13. 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.

  14. Equatorial Circular Geodesics in the Hartle-Thorne Spacetime

    CERN Document Server

    Bini, Donato; Ruffini, Remo; Siutsou, Ivan

    2013-01-01

    We investigate the influence of the quadrupole moment of a rotating source on the motion of a test particle in the strong field regime. For this purpose the Hartle-Thorne metric, that is an approximate solution of vacuum Einstein field equations that describes the exterior of any slowly rotating, stationary and axially symmetric body, is used. The metric is given with accuracy up to the second order terms in the body's angular momentum, and first order terms in its quadrupole moment. We give, with the same accuracy, analytic equations for equatorial circular geodesics in the Hartle-Thorne spacetime and integrate them numerically.

  15. Database of Whistler-mode Chorus in the Equatorial Plane

    Czech Academy of Sciences Publication Activity Database

    Macúšová, E.; Santolík, Ondřej

    Vol. 2. Prague: MATFYZPRESS, Prague, 2009 - (Šafránková, J.; Pavlů, J.), s. 56-61 ISBN 978-80-7378-102-6. [WDS 2009 - Annual Conference of Doctoral Students /18./. Praha (CZ), 02.06.2009-05.06.2009] R&D Projects: GA AV ČR IAA301120601 Grant ostatní: GA MŠk(CZ) ME 842 Institutional support: RVO:68378289 Keywords : Database * Whistler-mode * Chorus * Equatorial * Plane Subject RIV: BL - Plasma and Gas Discharge Physics

  16. Shielding analysis for ITER equatorial bio-shield plug

    International Nuclear Information System (INIS)

    ITER equatorial port cell outside bio-shield plug is a place for allowing free personnel access after shutdown which accommodates various sensitive equipment and pipes. To ensure the personnel safety in port cell after shutdown, the distribution of dose rate in port cell was studied. Based on VisualBUS (CAD-Based Multi-Functional 4D Neutronics Simulation System), dose rate calculations were completed in port cell after shutdown. The result showed that dose rates in port cell are still 2 orders of magnitude more than desired limit (10 μSv/h) after one day shutdown. The optimization of bio-shield was needed. (authors)

  17. Spatiotemporal variability and propagation of equatorial noise observed by Cluster

    Czech Academy of Sciences Publication Activity Database

    Santolík, Ondřej; Pickett, J. S.; Gurnett, D. A.; Maksimovic, M.; Cornilleau-Wehrlin, N.

    2002-01-01

    Roč. 107, A12, 1495 (2002), s. SMP 43-1-43-8, doi: 10.1029/2001JA009159. ISSN 0148-0227 R&D Projects: GA ČR GA205/01/1064 Grant ostatní: NASA (US) NAG5-9974 Institutional research plan: CEZ:AV0Z3042911; CEZ:MSM 113200004 Keywords : outer plasmasphere * proton-cyclotron frequency * electromagnetic equatorial noise Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.245, year: 2002

  18. Equatorial electron densities - seasonal and solar cycle changes

    International Nuclear Information System (INIS)

    The effect of season and Solar cycle on equatorial electron density distributions is examined in terms of the presently-understood dynamics of the ionosphere. While many of the features fit in well with the dynamics, the role of neutral winds seems to merit more importance than it has been given so far. The absence of a clear 'noon-time bite-out' in total electron content in the bottomside is rather puzzling in view of the fact that the E x B upward drift of ionization commences from altitudes of 180 km itself. (author)

  19. 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...

  20. High resolution 2-D maps of OI 630.0 nm thermospheric dayglow from equatorial latitudes

    Directory of Open Access Journals (Sweden)

    D. Pallam Raju

    Full Text Available The first-ever high resolution 2-D maps of OI 630.0 nm dayglow obtained from equatorial latitudes clearly reveal the movement as a large-scale feature of the equatorial ionization anomaly (EIA. These also show the presence of wave-like features classified as gravity waves presumably originating at the crest of the EIA, similar to the equatorial electrojet acting as a source of these waves. These results are presented and discussed.

    Key words. Atmospheric composition and structure (Airglow and aurora · Ionosphere (Equatorial ionosphere; Instruments and techniques.

  1. Non-terminal blood sampling techniques in Guinea pigs

    DEFF Research Database (Denmark)

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

    2014-01-01

    Guinea pigs possess several biological similarities to humans and are validated experimental animal models(1-3). However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce. The anatomical feature...... number of samples do not exceed guidelines for blood collection in laboratory animals(6). All the described methods have been thoroughly tested and applied for repeated in vivo blood sampling in studies within our research facility.......Guinea pigs possess several biological similarities to humans and are validated experimental animal models(1-3). However, the use of guinea pigs currently represents a relatively narrow area of research and descriptive data on specific methodology is correspondingly scarce. The anatomical features...... 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...

  2. Good Order at Sea in the Gulf of Guinea

    DEFF Research Database (Denmark)

    Jacobsen, Katja Lindskov; Nordby, Johannes

    2015-01-01

    In this chapter, we first outline the maritime security situation in the Gulf of Guinea region at present. It is examined in the context of Good Order at Sea. Second, we describe the most recent maritime security initiative launched during the Yaoundé Summit in 2013. During the summit, West and C...

  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. PMID:22044056

  4. Guinea pig ductus arteriosus. II - Irreversible closure after birth.

    Science.gov (United States)

    Fay, F. S.; Cooke, P. H.

    1972-01-01

    To investigate the mechanism underlying irreversibility of ductal closure after birth, studies were undertaken to determine the exact time course for the onset of irreversible closure of the guinea pig ductus arteriosus. Parallel studies of the reactivity of ductal smooth muscle to oxygen and studies of the postpartum cellular changes within the vessel were also carried out.

  5. 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...

  6. 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.

  7. 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

  8. 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...

  9. 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...

  10. Treponema pallidum-immobilizing antibodies in guinea pig experimental syphilis.

    OpenAIRE

    Wicher, K; Miller, J N; Urquhart, A W; Wicher, V

    1989-01-01

    Treponema pallidum-immobilizing (TPI) antibodies were examined in intradermally infected inbred strain 13 and adoptively immune inbred strain 2 guinea pigs. Both strains of animals produced TPI antibodies at or after 90 days of infection. TPI antibodies were not associated with the protective mechanism(s) operative after challenge in adoptively immune animals.

  11. 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.

  12. SpIES: The Spitzer IRAC Equatorial Survey

    Science.gov (United States)

    Timlin, John; Ross, Nicholas; Richards, Gordon T.; Lacy, Mark; Bauer, Franz E.; Brandt, W. Niel; Fan, Xiaohui; Haggard, Daryl; Makler, Martin; Myers, Adam D.; Schneider, Donald P.; Strauss, Michael A.; Urry, C. Megan; Zakamska, Nadia L.; SpIES Team

    2016-01-01

    We describe the first data release from the Spitzer-IRAC Equatorial Survey (SpIES); a large-area survey of the Equatorial SDSS Stripe 82 field using Warm Spitzer. SpIES was designed to probe enough volume to perform measurements of the z>3 quasar clustering and luminosity function in order to test various "AGN feedback'' models. Additionally, the wide range of multi-wavelength, multi-epoch ancillary data makes SpIES a prime location to identify both high-redshift (z>6) quasars as well as obscured quasars missed by optical surveys. SpIES maps ~115deg2 of Stripe 82 to depths of 6.3 uJy (21.9 AB Magnitudes) and 5.75 uJy (22.0 AB Magnitudes) at [3.6] and [4.5] microns respectively; depths significantly greater than WISE. Here we define the SpIES survey parameters and describe the image processing, source extraction, and catalog production methods used to analyze the SpIES data. Amongst our preliminary science results, we show high significance detections of spectroscopically confirmed, z~5 quasars in the SpIES data. This work is based [in part] on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

  13. 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.

  14. 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...

  15. Analysis of longitude variations in the equatorial spectrum of Saturn

    International Nuclear Information System (INIS)

    Ground-based and Voyager observations in and out of methane and ammonia bands are analyzed to search for longitudinal variations in Saturn's equatorial region. A model with reflecting layer at 2.1 bars, an extended haze to 170 mb, and an overlying thin stratospheric haze is adopted. Two sets of data are analyzed, a set of ground-based observations covering the 6000-66000 A spectral region and a set of Voyager 1 images obtained with the orange and methane filters. The spectral variations are not consistent with a variation in the height of the reflecting layer. They are modeled by variations in the single scattering albedo of the haze and in the specific abundance of gas in the haze. A methane mixing ratio of 2.2 (/sub -0.2//sup +0.8/) x 10-3 is derived, representing a CH ratio which is enhanced by a factor of 2.3 over the solar value. Estimate of the ammonia mixing ratio, 4.5 x 10-4, is a lower limit due to our assumption that ammonia exists at its saturation vapor pressure everywhere above the reflecting layer. There is no conclusive evidence that there are longitudinal variations in the structure of the Saturnian atmosphere in the Equatorial Region on a scale greater than 600 km

  16. 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.

  17. 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 ($m \\lesssim 7 M_\\odot$...

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. 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.

    pigment concentration from the Coastal Zone Color Scanner (CZCS). In the equatorial Pacific heat accumulation due to a higher abundance of chlorophyll pigments in the equatorial Pacific leads to a decrease of the mixed layer thickness. This generates...

  3. 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.

  4. 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.

  5. 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.

  6. Solar Wind Associated with Near Equatorial Coronal Hole

    Science.gov (United States)

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

    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 wavelengths 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.

  7. Modulation of subtropical stratospheric gravity waves by equatorial rainfall

    Science.gov (United States)

    Cohen, Naftali Y.; Boos, William R.

    2016-01-01

    Internal gravity waves influence a variety of phenomena in Earth's stratosphere and upper troposphere, including aviation weather turbulence and circulations that set high-altitude distributions of ozone and greenhouse gases. Here coupling between the dominant mode of subseasonal variability of the equatorial atmosphere—the Madden-Julian oscillation (MJO)—and subtropical stratospheric gravity waves created by flow over topography is documented for the first time. We use three different meteorological data sets to show that during boreal winter, the MJO modifies the vertical distribution of internal gravity wave drag induced by the Tibetan Plateau and the deposition of momentum into the stratosphere. This interaction, however, has no significant impact on the vertically integrated wave drag. Our findings raise new questions about how future changes in tropical rainfall might affect stratospheric variability and highlight the importance of local processes over Tibet for the circulations that set distributions of climatically important high-altitude trace gases.

  8. Re-Os systematics of St. Paul's Rocks, equatorial Atlantic.

    Science.gov (United States)

    Blusztajn, J.; Hart, S. R.

    2006-12-01

    St. Paul's Rocks, small islets in the middle of the equatorial Atlantic (0°56'N, 29°22'W) just north of the St. Paul's Fracture zone, represent oceanic peridotites that are unique compared to abyssal peridotites. The main difference is the occurrence of modally metasomatized peridotites containing hornblende and pargasite. These mantle peridotites from St. Paul's Rocks show large Os isotopic heterogeneity, with present day 187Os/188Os ratios ranging from 0.1179 to 0.1273. In contrast, two hornblendite samples have very radiogenic Os isotopic compositions of 0.221 and 0.284. The Os concentrations vary from 0.003 ppb (hornblendite) to 5.8 ppb (spinel peridotite). Pargasite peridotites contain on average about 1.6 ppb Os. Even modally metasomatized samples with hornblende and pargasite have subchondritic Os isotopic ratios, indicating that enrichment processes did not disturb the Os isotopic system. The only indication of pervasive enrichment is a very high Re content in two of the amphibole peridotites (0.7 and 2.2 ppb). The unradiogenic Os isotopic ratios in the peridotites record ancient melting events with model ages of about 1.5 Ga. Three alkali basalts dredged on the flank of St. Paul's Rocks (1966 Atlantis II-20 cruise) have relatively high Os contents (62 to 167 ppt) and are quite radiogenic, with 187Os/188Os ranging from 0.167 to 0.239. Data from this study indicates that mixing of the different lithologies observed on St. Paul's Rocks cannot produce 187Os/188Os as high as that observed in the dredged basalts. On the other hand, the similar 187Os/188Os in the hornblendites and alkali basalts show that interaction between basalts and mantle peridotites took place. The very low Os isotopic ratios in St. Paul's Rocks, in conjunction with other Os studies from the equatorial Atlantic, indicate dispersed heterogeneities of old subcontinental lithospheric material in the oceanic mantle.

  9. A tropospheric ozone maximum over the equatorial Southern Indian Ocean

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2012-05-01

    Full Text Available We examine the distribution of tropical tropospheric ozone (O3 from the Microwave Limb Sounder (MLS and the Tropospheric Emission Spectrometer (TES by using a global three-dimensional model of tropospheric chemistry (GEOS-Chem. MLS and TES observations of tropospheric O3 during 2005 to 2009 reveal a distinct, persistent O3 maximum, both in mixing ratio and tropospheric column, in May over the Equatorial Southern Indian Ocean (ESIO. The maximum is most pronounced in 2006 and 2008 and less evident in the other three years. This feature is also consistent with the total column O3 observations from the Ozone Mapping Instrument (OMI and the Atmospheric Infrared Sounder (AIRS. Model results reproduce the observed May O3 maximum and the associated interannual variability. The origin of the maximum reflects a complex interplay of chemical and dynamic factors. The O3 maximum is dominated by the O3 production driven by lightning nitrogen oxides (NOx emissions, which accounts for 62% of the tropospheric column O3 in May 2006. We find the contribution from biomass burning, soil, anthropogenic and biogenic sources to the O3 maximum are rather small. The O3 productions in the lightning outflow from Central Africa and South America both peak in May and are directly responsible for the O3 maximum over the western ESIO. The lightning outflow from Equatorial Asia dominates over the eastern ESIO. The interannual variability of the O3 maximum is driven largely by the anomalous anti-cyclones over the southern Indian Ocean in May 2006 and 2008. The lightning outflow from Central Africa and South America is effectively entrained by the anti-cyclones followed by northward transport to the ESIO.

  10. Efficacy of the Investigational Echinocandin ASP9726 in a Guinea Pig Model of Invasive Pulmonary Aspergillosis

    OpenAIRE

    Wiederhold, Nathan P.; Najvar, Laura K.; Matsumoto, Satoru; Bocanegra, Rosie A.; Herrera, Monica L.; Wickes, Brian L.; Kirkpatrick, William R.; Patterson, Thomas F.

    2015-01-01

    ASP9726 is an investigational echinocandin with in vitro activity against Aspergillus species. We evaluated the pharmacokinetics and efficacy of this agent in an established guinea pig model of invasive pulmonary aspergillosis. ASP9726 plasma concentrations were measured in guinea pigs administered either a single dose or multiple doses of this agent at 2.5, 5, and 10 mg/kg of body weight/day by subcutaneous injection. Immunosuppressed guinea pigs were inoculated with A. fumigatus AF293, and ...

  11. 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...

  12. Establishment of a leptospirosis model in guinea pigs using an epicutaneous inoculations route

    OpenAIRE

    Zhang Yan; Lou Xiao-Li; Yang Hong-Liang; Guo Xiao-Kui; Zhang Xiang-Yan; He Ping; Jiang Xu-Cheng

    2012-01-01

    Abstract Background Leptospires are presumed to enter their host via small abrasions or breaches of the skin. The intraperitoneal route, although commonly used in guinea pig and hamster models of leptospirosis, does not reflect conditions encountered during natural infection. The aim of this study is to develop a novel leptospirosis guinea pig model through epicutaneous route and to elucidate the pathogenesis of leptospirosis in experimental guinea pigs by comparing the data from other studie...

  13. 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, partly due to the...

  14. 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

  15. Homologous radioimmunoassay for guinea pig corticosteroid-binding globulin

    International Nuclear Information System (INIS)

    A rapid, specific, and sensitive (requiring only 20 fmole of antigen equivalent to 0.007) μl of serum) radioimmunoassay (RIA) was developed for the measurement of guinea pig corticosteroid-binding globulin (CBG). CBG was purified to homogeneity from guinea pig serum by affinity chromatography and used for immunization, as the standard and as the radiolabeled trace in the RIA. The antiserum to CBG was raised in rabbits. It was judged specific by immunoelectrophoresis and by comparison of RIA values with steroid-binding assay profiles obtained on serum separated on the basis of size and ion-exchange properties. The results of the radioimmunoassays agree with those of a steroid-binding assay run on identical samples. The sensitivity of the assay allows detection of CBG in serial serum samples, other biologic fluids such as milk, and cell culture supernatants

  16. 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

  17. 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

  18. 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.

  19. 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...

  20. Chemical Defense of an Ozaenine Bombardier Beetle From New Guinea

    OpenAIRE

    Jerrold Meinwald; Blankespoor, Curtis L.; Maria Eisner; Thomas Eisner; Braden Roach; Aneschansley, Daniel J.; Ball, George E.

    1989-01-01

    We had occasion recently to study 3 live specimens of Pseudozaena orientalis opaca, an ozaenine carabid beetle (subfamily Paussinae, tribe Ozaenini) from New Guinea, and report here on the biology and chemistry of its defensive spray mechanism. A number of New World ozaenines had previously been studied chemically and shown to be “bombardiers” that discharge a hot quinonoid mixture (Aneshansley et al. 1969, 1983; Eisner and Aneshansley 1982; Eisner et al. 1977; Roach et al. 1979). Pseudozaena...

  1. 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...

  2. Venereal diseases in the Pacific Islands. Papua New Guinea.

    OpenAIRE

    Willcox, R. R.

    1980-01-01

    Papua New Guinea, which contains nearly three-quarters of the population of the 20 islands, or island groups, studied by the South Pacific Commission has a commensurate proportion of reported cases of syphilis and gonorrhoea. It is a country with an exceptional interest for the venereologist as it exhibits all the facets of venereal disease problems as experienced the world over. With the opening up of communications syphilis has gained a foothold in what were areas previously endemic with ya...

  3. Protection of intellectual, biological & cultural property in Papua New Guinea

    OpenAIRE

    Whimp, Kathy; Busse , Mark

    2013-01-01

    Intellectual, biological and cultural property rights are a powerful and debatable topic. They offer the possibility for protection of rights to intangible resources, including the products of knowledge and creativity. The forces of globalisation have made this subject of immediate, international concern. Struggles for ownership of intellectual property occur between and within local and global arenas. This book examines important questions which Papua New Guinea must ask in the developme...

  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. 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...

  6. 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...

  7. 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

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

    OpenAIRE

    Haberle, Simon G.

    2007-01-01

    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 presen...

  9. Acute effects of aflatoxins on guinea pig isolated ileum.

    Science.gov (United States)

    Luzi, A; Cometa, M F; Palmery, M

    2002-10-01

    Previous studies on the aflatoxins have focused mainly on their chronic toxic effects. In this study we investigated the acute gastrointestinal effects of four common aflatoxins on isolated guinea pig ileum. AFB(1) (EC(50) 4.6+/-0.4 microM) and AFB(2) (EC(50)17+/-4.4 microM) contracted isolated guinea pig ileum in a dose-dependent manner, whereas AFG(1) and AFG(2) evoked no contractions. Atropine (5.9 nM 11.8 and 23.6 nM) antagonized AFB(1)-induced contractions in a dose-dependent manner. Pretreatment with the nicotinic ganglionic blocker, hexamethonium (up to 55 microM), left AFB(1)-induced contractions unchanged. In contrast, tetrodotoxin (0.3 microM), blocked AFB(1) contractile activity. The two inhibitors of ACh release, morphine (0.3 microM) and clonidine (0.4 microM), antagonized EC(50) AFB(1)-induced contractions, and apamin, a drug that increases neuronal excitability, facilitated the EC(50) AFB(1)-induced contractile effect. The choline uptake blocker, hemicholinium (17.4 microM) markedly reduced AFB(1)-induced contractions. These results suggest that aflatoxins induce their contractile effect indirectly through the cholinergic system by stimulating acetylcholine release from the postganglionic parasympathetic nerve endings. The acute actions of aflatoxins on isolated guinea pig ileum could explain their acute gastrointestinal effects in humans and animals. PMID:12206819

  10. 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

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

    International Nuclear Information System (INIS)

    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')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 125I-F(ab')2 (AB1) to the antiidiotype was inhibited 90% in the presence of DT.F(ab')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')2 of anti-idiotype IgG1/2 (AB2). Of the ten animals inoculated with AB2, three tested positive by RIA against 125I-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

  12. 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.

  13. 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

  14. 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.)

  15. 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.

  16. Sea surface and subsurface circulation dynamics off equatorial Peru during the last ~17 kyr

    Science.gov (United States)

    Nürnberg, Dirk; Böschen, Tebke; Doering, Kristin; Mollier-Vogel, Elfi; Raddatz, Jacek; Schneider, Ralph

    2015-07-01

    The complex deglacial to Holocene oceanographic development in the Gulf of Guayaquil (Eastern Equatorial Pacific) is reconstructed for sea surface and subsurface ocean levels from (isotope) geochemical proxies based on marine sediment cores. At sea surface, southern sourced Cold Coastal Water and tropical Equatorial Surface Water/Tropical Surface Water are intimately related. In particular since ~10 ka, independent sea surface temperature proxies capturing different seasons emphasize the growing seasonal contrast in the Gulf of Guayaquil, which is in contrast to ocean areas further offshore. Cold Coastal Water became rapidly present in the Gulf of Guayaquil during the austral winter season in line with the strengthening of the Southeast Trades, while coastal upwelling off Peru gradually intensified and expanded northward in response to a seasonally changing atmospheric circulation pattern affecting the core locations intensively since 4 ka BP. Equatorial Surface Water, instead, was displaced and Tropical Surface Water moved northward together with the Equatorial Front. At subsurface, the presence of Equatorial Under Current-sourced Equatorial Subsurface Water was continuously growing, prominently since ~10-8 ka B.P. During Heinrich Stadial 1 and large parts of the Bølling/Allerød, and similarly during short Holocene time intervals at ~5.1-4 ka B.P. and ~1.5-0.5 ka B.P., the admixture of Equatorial Subsurface Water was reduced in response to both short-term weakening of Equatorial Under Current strength from the northwest and emplacement by tropical Equatorial Surface Water, considerably warming the uppermost ocean layers.

  17. 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...

  18. Characteristics of Extreme Summer Convection over equatorial America and Africa

    Science.gov (United States)

    Zuluaga, M. D.; Houze, R.

    2013-12-01

    Fourteen years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) version 7 data for June-August show the temporal and spatial characteristics of extreme convection over equatorial regions of the American and African continents. We identify three types of extreme systems: storms with deep convective cores (contiguous convective 40 dBZ echoes extending ≥10 km in height), storms with wide convective cores (contiguous convective 40 dBZ echoes with areas >1,000 km2) and storms with broad stratiform regions (stratiform echo >50,000 km2). European Centre for Medium-Range Weather Forecast (ECMWF) reanalysis is used to describe the environmental conditions around these forms of extreme convection. Storms with deep convective cores occur mainly over land: in the equatorial Americas, maximum occurrence is in western Mexico, Northern Colombia and Venezuela; in Africa, the region of maximum occurrence is a broad zone enclosing the central and west Sudanian Savanna, south of the Sahel region. Storms with wide convective radar echoes occur in these same general locations. In the American sector, storms with broad stratiform precipitation regions (typifying robust mesoscale convective systems) occur mainly over the eastern tropical Pacific Ocean and the Colombia-Panama bight. In the African sector, storms with broad stratiform precipitation areas occur primarily over the eastern tropical Atlantic Ocean near the coast of West Africa. ECMWF reanalyses show how the regions of extreme deep convection associated with both continents are located mainly in regions affected by diurnal heating and influenced by atmospheric jets in regions with strong humidity gradients. Composite analysis of the synoptic conditions leading to the three forms of extreme convection provides insights into the forcing mechanisms in which these systems occur. These analyses show how the monsoonal flow directed towards the Andes slopes is mainly what concentrates the occurrence of extreme

  19. 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

    OpenAIRE

    María Teresa Abaga Envó

    2009-01-01

    Resumen: Una lectura sobre los estudios narratológicos revela que el acto narrativo es un hecho consustancial al ser humano. “Somos el homo sapiens, porque somos el homo narrans”, diría el académico José María Merino (2002: 57). De las estructuras narrativas, el cuento oral tradicional se alza como la forma más antigua. Tan antigua y presente en todos los pueblos que componentes semánticos y formales se repiten en relatos de distintas culturas. Tales aspectos constituyen el objeto de análisis...

  20. 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.

  1. Ubiquitous equatorial accretion disc winds in black hole soft states

    CERN Document Server

    Ponti, G; Begelman, M C; Dunn, R J H; Neilsen, J; Coriat, M

    2012-01-01

    High resolution spectra of Galactic Black Holes (GBH) reveal the presence of highly ionised absorbers. In one GBH, accreting close to the Eddington limit for more than a decade, a powerful accretion disc wind is observed to be present in softer X-ray states and it has been suggested that it can carry away enough mass and energy to quench the radio jet. Here we report that these winds, which may have mass outflow rates of the order of the inner accretion rate or higher, are an ubiquitous component of the jet-free soft states of all GBH. We furthermore demonstrate that these winds have an equatorial geometry with opening angles of few tens of degrees, and so are only observed in sources in which the disc is inclined at a large angle to the line of sight. The decrease in Fe XXV / Fe XXVI line ratio with Compton temperature, observed in the soft state, suggests a link between higher wind ionisation and harder spectral shapes. Although the physical interaction between the wind, accretion flow and jet is still not ...

  2. Balanced Data Assimilation For Improving Zonal Equatorial Currents

    Science.gov (United States)

    Burgers, G.; Balmaseda, M. A.; Vossepoel, F. C.; van Oldenborgh, G. J.; van Leeuwen, P. J.

    Assimilation schemes that are used for seasonal prediction can have a problem in estimating zonal velocities near the equator. This is the case for OI schemes that use density information for updating only the model density field. In some situations, this leads to a detoriation of the zonal velocity field around the equator. The problem is studied first for the assimilation of height observations in a simple linear 1.5 layer shallow-water model of the equatorial Pacific. It is found that equa- torial zonal velocities can be degraded if velocity is not updated in the assimilation procedure, even if the assimilation increments for height are spread over time. Adding updates to the zonal velocity which are related by geostrophic balance to the height updates is shown to be a simple remedy for the shallow-water model. A straightforward generalisation of the balanced data assimilation method has been implemented in the ocean circulation model of the ECMWF seasonal forecasting sys- tem. First tests are encouraging: upper-ocean surface currents are improved, and cou- pled hindcasts are improved if balanced assimilation is used for the ocean analyses.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Solar wind disturbances caused by solar flares: equatorial plane

    International Nuclear Information System (INIS)

    The propagation of solar wind disturbances caused by single, double and six successive flares in the dipolar and quadrupolar patterns of the interplanetary magnetic field (IMF) and the associated solar wind flow are studied. This study is based on a kinematic and empirical method developed by Hakamada and Akasofu (1982). Each flare is characterized by six parameters (such as the highest speed flow, its extent and duration). The successive IMF patterns in the equatorial plane of the heliosphere during a time span of 0.5-60 days after flares are presented for a variety of flares. The solar wind speed and IMF magnitude are also given as a function of distance along a radial line fixed in space and also as a function of time at several points fixed in space (simulating approximately space probe observations). Some of the results are qualitatively compared with recent space probe observations, demonstrating fair similarity with the observed time profiles of solar wind speed variations over a wide range of both distances (0-10 a.u.) and time spans (60 days). This method provides a first order construction, temporal and spatial, of flare-induced shocks and their multiple interactions with each other, as well as with the corotating interaction regions. (author)

  8. 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.

  9. 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.

  10. 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.

  11. Test Blanket Module Pipe Forest integration in ITER equatorial port

    International Nuclear Information System (INIS)

    ITER Test Blanket Modules (TBMs) will allow testing Breeding Blanket concepts for a future application in DEMO. IRFM (Institut de Recherche sur la Fusion Magnetique) contribution to this test program consists in the integration of the 2 European TBMs (Helium Cooled Lithium Lead and Helium Cooled Pebble Bed) in a dedicated equatorial port. The two Breeding Blanket concepts use Helium gas as a coolant, liquid PbLi as breeder (for HCLL process) and Helium gas for Tritium extraction (for HCPB process). These materials are passing through the cryostat interspace forming a pipe network called the Pipe Forest. The main structural function of the Pipe Forest is to absorb the thermal expansion due to the Vacuum Vessel and due to the pipe system itself. The Pipe Forest has to cope with several design issues. In this study, the different key parameters of the Pipe Forest design are identified and their relative influence is analysed. Several design options were investigated and compared based on: -Thermo-mechanical finite element calculations -Pipe Forest integration within the cryostat interspace -Interface management -Assembly and maintenance scenarios -Complex pipe routing due to the expansion bends -RCC-MR 2007 requirements The chosen thermal compensation solution (thermal expansion loops) led to a Pipe Forest design. The CAE analysis of this Pipe Forest showed that it fulfills the requirements of the RCC-MR 2007, which is the reference design and construction code selected for the European TBM.

  12. 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...

  13. 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

  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. 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…

  16. 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....

  17. 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.

    asymmetry, does not support a chlorophyll pigments distribution in the equatorial wave-guide to bring about a meridional density gradient by altering the penetration of solar radiation. Relevant upper ocean circulations modulated by phytoplanktons...

  18. Bacterial Diversity in Deep-Sea Sediments from Afanasy Nikitin Seamount, Equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, R.; Meena, R.M.; Deobagkar, D.D.

    Deep-sea sediments can reveal much about the last 200 million years of Earth history, including the history of ocean life and climate. Microbial diversity in Afanasy Nikitin seamount located at Equatorial East Indian Ocean (EEIO) was investigated...

  19. 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....

  20. 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...

  1. Seasonal persistence of ozone and zonal wind anomalies in the equatorial stratosphere

    OpenAIRE

    Tegtmeier, S.; Fioletov, V. E.; Shepherd, T. G.

    2010-01-01

    Analysis of the variability of equatorial ozone profiles in the Satellite Aerosol and Gas Experiment-corrected Solar Backscatter Ultraviolet data set demonstrates a strong seasonal persistence of interannual ozone anomalies, revealing a seasonal dependence to equatorial ozone variability. In the lower stratosphere (40–25 hPa) and in the upper stratosphere (6–4 hPa), ozone anomalies persist from approximately November until June of the following year, while ozone anomalies in the layer between...

  2. 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.

  3. 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....

  4. Observation of equatorial Kelvin solitary waves in a slowly varying thermocline

    OpenAIRE

    Zheng, Q; R. D. Susanto; X.-H. Yan; W. T. Liu; C.-R. Ho

    1998-01-01

    TOPEX/POSEIDON (T/P) sea level deviation (SLD) time series from 3 October 1992 to 15 May 1997 combined with upper ocean thermal structures are used to observe the characteristics and analyze the dynamics of equatorial waves in the Pacific Ocean. The evolution of the Kelvin wave propagating along an eastward shoaling thermocline in the equatorial Pacific is investigated. The behaviour of this wave as it propagates eastward can be approximately described with the solutions of the perturbed Kort...

  5. 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 ...

  6. 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.

  7. The effect of J2 on equatorial and halo orbits around a magnetic planet

    International Nuclear Information System (INIS)

    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. 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.

  9. A First Generation Comparative Chromosome Map between Guinea Pig (Cavia porcellus) and Humans.

    Science.gov (United States)

    Romanenko, Svetlana A; Perelman, Polina L; Trifonov, Vladimir A; Serdyukova, Natalia A; Li, Tangliang; Fu, Beiyuan; O'Brien, Patricia C M; Ng, Bee L; Nie, Wenhui; Liehr, Thomas; Stanyon, Roscoe; Graphodatsky, Alexander S; Yang, Fengtang

    2015-01-01

    The domesticated guinea pig, Cavia porcellus (Hystricomorpha, Rodentia), is an important laboratory species and a model for a number of human diseases. Nevertheless, genomic tools for this species are lacking; even its karyotype is poorly characterized. The guinea pig belongs to Hystricomorpha, a widespread and important group of rodents; so far the chromosomes of guinea pigs have not been compared with that of other hystricomorph species or with any other mammals. We generated full sets of chromosome-specific painting probes for the guinea pig by flow sorting and microdissection, and for the first time, mapped the chromosomal homologies between guinea pig and human by reciprocal chromosome painting. Our data demonstrate that the guinea pig karyotype has undergone extensive rearrangements: 78 synteny-conserved human autosomal segments were delimited in the guinea pig genome. The high rate of genome evolution in the guinea pig may explain why the HSA7/16 and HSA16/19 associations presumed ancestral for eutherians and the three syntenic associations (HSA1/10, 3/19, and 9/11) considered ancestral for rodents were not found in C. porcellus. The comparative chromosome map presented here is a starting point for further development of physical and genetic maps of the guinea pig as well as an aid for genome assembly assignment to specific chromosomes. Furthermore, the comparative mapping will allow a transfer of gene map data from other species. The probes developed here provide a genomic toolkit, which will make the guinea pig a key species to unravel the evolutionary biology of the Hystricomorph rodents. PMID:26010445

  10. Vaccination against bovine herpes mammillitis virus infections in guinea pigs.

    Science.gov (United States)

    Smee, D F; Leonhardt, J A

    1994-01-01

    Bovine herpes mammillitis virus or bovine herpesvirus type 2 (BHV-2) causes ulcerative lesions on the teats and udders of infected cows. Since no commercial vaccine is available for this disease, we investigated certain experimental BHV-2 vaccines against this virus in infected guinea pigs. Vaginally infected guinea pigs get severe, self-limiting vaginal infections characterized by erythema and swelling and the production of measurable vaginal virus titers. Two vaccine approaches were investigated: vaccination with wild-type (WT) virus by the subcutaneous route, and vaccination either subcutaneously or intravaginally with a thymidine kinase (TK) deficient (TK-) virus. The TK- strain was prepared by passage of BHV-2 in the presence of the potent TK-dependent antiviral agent 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-methyluracil (FMAU). The antiviral activity of FMAU against the virus in plaque reduction assays changed from 0.05 to 2 microM at the same time that the TK activity of the mutant virus decrease to 7% of WT virus TK activity. Subcutaneous vaccination of guinea pigs with WT and TK- viruses did not induce vaginal infection. Primary vaginal infection (vaccination) with the TK- virus led to greatly reduced lesion severity compared to vaginal infection with the WT virus. However, the amount of vaginal virus titers recovered during these primary infections was similar for both TK- and WT viruses, indicating that both viruses had equal infecting potential. Thirty days after vaccination the animals were re-infected intravaginally with WT virus. The vaccinated animals showed dramatically reduced lesion severity and low recoverable virus titers compared to age-matched nonvaccinated animals.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7928285

  11. 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

  12. 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...

  13. 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 ...

  14. 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...

  15. Papua New Guinea seeks industry to support river development

    Energy Technology Data Exchange (ETDEWEB)

    Scott, W.E.

    1978-07-01

    Feasibility studies support the Papua New Guinea government's plans for hydroelectric development on the Purari River if industry can be attracted to the largely unsettled area to absorb most of the power generated. A 30-month design and mobilization period, followed by 5/sup 1///sub 2/ years of construction are indicated for the proposed 1800 megawatt project. The region could develop into an international industrial megapolis supplied with cheap power and transport, abundant fresh water, and large supplies of forest and mineral resources. The government is exploring the drain on manpower resources and the inflationary and environmental effects of rapid development on the rest of the country.

  16. 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...

  17. 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

  18. Antimicrobial activity of Guinea-Bissau traditional remedies.

    Science.gov (United States)

    Silva, O; Duarte, A; Cabrita, J; Pimentel, M; Diniz, A; Gomes, E

    1996-01-01

    The ethanolic extracts of twelve plants selected through ethnomedical survey in Guinea-Bissau were investigated for their in vitro antimicrobial properties over ten bacteria and Candida albicans, using agar diffusion and dilution methods. All the tested extracts showed some activity against at least one of the bacteria. Most of the extracts (79%) showed activity against Staphylococcus aureus and only one (Cryptolepis sanguinolenta) against Escherichia coli. Cryptolepis sanguinolenta and Terminalia macroptera root extracts showed some activity against Candida albicans as well as showing an interesting profile of activity against most of the enteropathogen microorganisms. Inhibition zones against Staphylococcus aureus were localised on extract chromatograms by bioautographic techniques. PMID:8778508

  19. 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.

  20. 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.

  1. Magnetospheric conditions near the equatorial footpoints of proton isotropy boundaries

    Science.gov (United States)

    Sergeev, V. A.; Chernyaev, I. A.; Angelopoulos, V.; Ganushkina, N. Y.

    2015-12-01

    Data from a cluster of three THEMIS (Time History of Events and Macroscale Interactions during Substorms) spacecraft during February-March 2009 frequently provide an opportunity to construct local data-adaptive magnetospheric models, which are suitable for the accurate mapping along the magnetic field lines at distances of 6-9 Re in the nightside magnetosphere. This allows us to map the isotropy boundaries (IBs) of 30 and 80 keV protons observed by low-altitude NOAA POES (Polar Orbiting Environmental Satellites) to the equatorial magnetosphere (to find the projected isotropy boundary, PIB) and study the magnetospheric conditions, particularly to evaluate the ratio KIB (Rc/rc; the magnetic field curvature radius to the particle gyroradius) in the neutral sheet at that point. Special care is taken to control the factors which influence the accuracy of the adaptive models and mapping. Data indicate that better accuracy of an adaptive model is achieved when the PIB distance from the closest spacecraft is as small as 1-2 Re. For this group of most accurate predictions, the spread of KIB values is still large (from 4 to 32), with the median value KIB ~13 being larger than the critical value Kcr ~ 8 expected at the inner boundary of nonadiabatic angular scattering in the current sheet. It appears that two different mechanisms may contribute to form the isotropy boundary. The group with K ~ [4,12] is most likely formed by current sheet scattering, whereas the group having KIB ~ [12,32] could be formed by the resonant scattering of low-energy protons by the electromagnetic ion-cyclotron (EMIC) waves. The energy dependence of the upper K limit and close proximity of the latter event to the plasmapause locations support this conclusion. We also discuss other reasons why the K ~ 8 criterion for isotropization may fail to work, as well as a possible relationship between the two scattering mechanisms.

  2. 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).

  3. The solar wind origin of the equatorial ionosphere parameters variation during geomagnetic storms

    International Nuclear Information System (INIS)

    Complete text of publication follows. The interplanetary magnetic field, geomagnetic variations, virtual ionosphere height h'F and the critical frequency foF2 data during the geomagnetic storms are studied to demonstrate relationships between these phenomena. We study 5-min ionospheric variations using the first Western Pacific Ionosphere Campaign (1998 - 1999) observations, 5-min interplanetary magnetic field (IMF) and 5-min auroral electrojets data during a moderate geomagnetic storm. The ionospheric 5-min variations at the equatorial stations which allow calculating in detail time delays of the auroral and equatorial ionospheric phenomena are scantily known. These data allowed us to demonstrate that the auroral and the equatorial ionospheric phenomena are developed practically simultaneously. Hourly average of the ionospheric foF2 and h'F variations at near equatorial stations during a similar storm show the same behavior. We suppose this is due to interaction between electric fields of the auroral and the equatorial ionosphere during geomagnetic storms. It is shown that the low-latitude ionosphere dynamics during these moderate storms was defined by the southward direction of the Bz-component of the interplanetary magnetic field. A southward IMF produces the Region 1 and Region 2 the field-aligned currents (FAC) and polar electrojet current systems. We assume that the short-term ionospheric variations during geomagnetic storms can be explained mainly by the electric field of the FAC. The electric fields of the field-aligned currents can penetrate throughout the mid-latitude ionosphere to the equator and may serve as a coupling agent between the auroral and the equatorial ionosphere. The storm wind driven electric fields which responsible for the larger amplitudes and longer lifetimes of the drift perturbations are discussed. It is shown that model simulations as disturbed ionospheric wind dynamo d o not allow explaining a significant part of the experimental

  4. 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.

  5. 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.

  6. Placental transfer of ruthenium in rat and guinea-pig

    International Nuclear Information System (INIS)

    Ruthenium-106 in citrate solution was administered intravenously to rat at different stages of pregnancy and to guinea-pig either before conception or in late pregnancy. The results for rat showed that retention in the embryo/foetus measured at 3-5 days after administration increased from about 0.0002% of injected activity per embryo/foetus on day 12 of gestation to about 0.05% at birth. The relative concentrations of 106Ru in embryo/foetus and mother (Cf/Cm ratio) were about 0.1 in each case. Concentrations in the yolk sac on day 12 were about 1% g-1 compared with 0.01% g-1 kin the foetus/ Retention in the guinea-pig foetus in late gestation at 7 days after administration (days 50-57) was about 0.2% injected activity per foetus, corresponding to a Cf/Cm = 0.2. Retention in each foetoplacental unit was 2% of injected 106Ru with 50% in the yolk sac, 35% in the placenta and 10% in the foetus. For administration 4 weeks prior to conception, the level of 106Ru retained in the foetus on day 57 of gestation was two orders of magnitude lower than after short-term administration, with a Cf/Cm about 0.004. (author)

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. [Studies on coccidiosis in guinea pigs. 2. Epizootiological survey].

    Science.gov (United States)

    Muto, T; Yusa, T; Sugisaki, M; Tanaka, K; Noguchi, Y; Taguchi, K

    1985-01-01

    An epizootiological survey has been carried out on naturally occurring coccidiosis in Hartley guinea pigs (weight, 250g) purchased by the National Institute of Health, Tokyo during the period 1964 to 1982. Coccidial infections in breeding colonies of guinea pigs were observed very frequently in weaned animals but scarcely in adult and suckling animals. Oocysts of Eimeria caviae were detected in 53.8% of the 7,162 fecal samples collected from transportation boxes and coccidiosis occurred in 39% of the 1,461 dead or culled animals obtained during the routine one week quarantine period. In the period 1964 to 1971, particularly high rates of prevalence of oocysts, between 55-86%, and incidence of coccidiosis, between 55-76%, were observed. These rates were clearly reduced in the period 1972 to 1982, with a lower rate of isolation of oocysts ranging from 14-48% and les than 20% incidence of coccidiosis (except in 1981 and 1982). The monthly fluctuation of occurrence rates of oocysts and clinical coccidiosis differed over the period of study. From 1964 to 1971, the high prevalence of oocysts was consistently observed accompanied by a bimodal pattern of incidence of coccidiosis in April (85%) and October (78%). In the period 1972 to 1982, both parameters showed a single peak, for prevalence of oocysts in June (60.7%) and for incidence of coccidiosis in May (45%). Oocysts in feces disappeared in February and March and coccidiosis occurred irregularly in 1981 and 1982.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3987821

  12. 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)

  13. Characterization of gastrin receptors on guinea pig pancreatic acini

    International Nuclear Information System (INIS)

    Recent studies have demonstrated gastrin receptors in some pancreatic tumors and that gastrin is a potent stimulant of pancreatic Na+-H+ exchange. In the present study the authors used 125I-labeled gastrin (125I-gastrin) to characterize gastrin receptors on guinea pig pancreatic acini. Binding of 125I-gastrin was temperature dependent, saturable, and specific for gastrin-related peptides. Analysis demonstrated a single class of receptors with high affinity for gastrin and a binding capacity of 1 fmol/mg protein. Binding of 125I-gastrin was inhibited with the following relative potencies: cholecystokinin octapeptide (CCK-8) > gastrin-17-I = gastrin-34-I > pentagastrin > desulfated [des(SO3)]CCK-8 > CCK-4 and by the receptor antagonists CBZ-CCK-27-32-NH2 > proglumide analogue 10 > asperlicin > Bt2-guanosine 3',5'-cyclic monophosphate. The present results demonstrate that guinea pig pancreatic acini possess gastrin receptors that have a high affinity for gastrin and are distinct from CCK receptors previously described. Only occupation of the CCK receptors results in enzyme secretion. Gastrin receptors on pancreatic acini resemble those described in parietal cells and gastric glands; however, their function is unknown

  14. 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.

  15. Investigation Into the Humaneness of Slaughter Methods for Guinea Pigs (Cavia porcelus) in the Andean Region.

    Science.gov (United States)

    Limon, Georgina; Gonzales-Gustavson, Eloy A; Gibson, Troy J

    2016-01-01

    Guinea pigs (Cavia porcelus) are an important source of nonhuman animal protein in the Andean region of South America. Specific guidelines regarding the welfare of guinea pigs before and during slaughter have yet to be developed. This study critically assessed the humaneness of 4 different stunning/slaughter methods for guinea pigs: cervical neck dislocation (n = 60), electrical head-only stunning (n = 83), carbon dioxide (CO2) stunning (n = 21), and penetrating captive bolt (n = 10). Following cervical neck dislocation, 97% of guinea pigs had at least 1 behavioral or cranial/spinal response. Six percent of guinea pigs were classified as mis-stunned after electrical stunning, and 1% were classified as mis-stunned after captive bolt. Increased respiratory effort was observed during CO2 stunning. Apart from this finding, there were no other obvious behavioral responses that could be associated with suffering. Of the methods assessed, captive bolt was deemed the most humane, effective, and practical method of stunning guinea pigs. Cervical neck dislocation should not be recommended as a slaughter method for guinea pigs. PMID:26963642

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Citicoline retards myopia progression following form deprivation in guinea pigs.

    Science.gov (United States)

    Mao, Junfeng; Liu, Shuangzhen; Fu, Chunyan

    2016-06-01

    The retinal dopaminergic system is involved in the myopic shift following form deprivation. Citicoline has been demonstrated to stimulate the dopaminergic system in the brain and retina. Furthermore, citicoline has been used in many neurogenic diseases, such as senile cognitive impairment, stroke and Parkinson's disease as well as in amblyopia and glaucoma. Our aim was to investigate the effect of citicoline on the refractive state and retinal dopamine level in form deprivation myopia of guinea pigs. Guinea pigs, at an age of four weeks, were randomly divided into normal control, deprivation, deprived + citicoline and deprived + vehicle groups. Form deprivation myopia was induced by a translucent eye shield covering the right eye. Citicoline was injected intraperitoneally twice a day (500 mg/kg, 9 am and 9 pm) for 10 days. In vitro, retinal explants were cultured with citicoline for 24 h, with a final citicoline concentration of 100 µmol/L. The ocular refractive parameters and retinal dopamine content were measured. After occlusion for 10 days, the form-deprived eyes became myopic with an increase in axial length and a decrease in retinal dopamine content. The intraperitoneal injection of citicoline reduced the myopic degree (from -3.25 ± 0.77D to -0.62 ± 0.47D, P < 0.001) and partially raised retinal dopamine levels (from 0.55 ± 0.21 ng to 0.81 ± 0.24 ng, P < 0.01) in the form-deprived eyes. After 24 h of culturing retinal explants with citicoline, retinal dopamine content increased significantly (from 0.42 ± 0.14 ng to 0.62 ± 0.21 ng, P < 0.05). These results demonstrated that an intraperitoneal injection of citicoline could retard the myopic shift induced by form deprivation in guinea pigs, which was mediated by an increase in the retinal dopamine levels. PMID:26979720

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Normal behavior and the clinical implications of abnormal behavior in guinea pigs.

    Science.gov (United States)

    Bradley, T A

    2001-09-01

    Cavies are becoming more popular as pets because they are relatively easy to care for and provide never-ending love and entertainment with their curious but gentle nature. As with other species, the best way to learn about guinea pig behavior is to own guinea pigs. Understanding normal behavior provides the practitioner with the ability to more easily recognize pathology and abnormal behavior. This allows the veterinarian to provide necessary supportive care and pain management more quickly while performing diagnostics and determining the need for therapeutics. Understanding the behavior of cavies allows the clinician to better educate guinea pig-owning clients and to better and more quickly serve the needs of their guinea pig patients. PMID:11601108

  13. 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.

  14. 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

  15. 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 ...

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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...

  1. Prenatal effects of trichlorfon on the guinea pig brain

    International Nuclear Information System (INIS)

    The organophosphorus compound trichlorfon, dimethyl (2,2,2-trichloro-1-hydroxyethyl) phosphonate, was administered by stomach tube (100 mg/kg) to pregnant guinea pigs at two different stages of gestation (days 36, 37, 38 and 51, 52, 53). The pups developed locomotory disturbances, and post mortem examination revealed significantly decreased weights of the total brain and the cerebellum, as compared to controls. There was also a significant weight reduction particularly of the medulla oblongata, but also of the hippocampus, the thalamus, and the colliculi. Histological examination of the cerebellum revealed reduction of the external granular layer and the molecular layer, and regional absence of Purkinje cells. The activities of the neutrotransmitter enzymes choline acetyltransferase (ChAT), and glutamate decarboxylase (GAD) in cerebellum were reduced as compared to the control values. (orig.)

  2. 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

  3. 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

  4. Oxygen radicals stimulate guinea pig gallbladder glycoprotein secretion in vitro

    International Nuclear Information System (INIS)

    In several animal models of cholelithiasis, and in humans with gallstones, hypersecretion of gallbladder mucin is observed. This study was undertaken to determine the effect of oxygen radicals on guinea pig gallbladder glycoprotein secretion in organ culture. Mucosal explants were incubated with [3H]glucosamine hydrochloride to label glycoproteins, then exposed to oxygen radicals generated by chelated ferric iron and ascorbic acid. Marked stimulation of glycoprotein release was observed after a 30-min exposure to the oxygen radical-generating system, and the effect was inhibited by mannitol. The stimulatory effect of hydroxyl radical was not accompanied by leakage of intracellular lactate dehydrogenase. Parallel experiments with human granulocytes activated with f-Met-Leu-Phe and coincubated with gallbladder explants revealed similar results. These results indicate that oxygen radicals, especially the hydroxyl radical (OH), are capable of stimulating rapid release of mucous-type glycoproteins from gallbladder epithelium

  5. [Scanning electron microscopy study of experimental chorioretinitis in guinea pigs].

    Science.gov (United States)

    Renard, G; Usui, M; De Kozak, Y; Faure, J P

    1976-04-01

    Retinal lesions are described with the scanning electron microscope in the uveo retinitis induced in guinea pigs by immunization with rod outer segments of bovine retina. The two surfaces in contact of the pigment epithelium and the photoreceptors are separated from each other and observed on flat preparations. On the epithelial side, the evolution of the degenerescence of epithelial cells is observed, from the early disappearance of villosities until the total destruction of the cells. Through lacks in the epithelial layer where the choroid appears, inflammatory cells migrate towards the retina. The impairement of the visual cells is characterized by progressive destruction of outer then inner segments, with preservation of the external limiting membrane. In some areas the degenerative process reaches the layer of visual cells nuclei. Macrophages, and local clusters of lymphocytes are seen in contact with the retinal surface. PMID:135548

  6. Ototoxicity of acetic acid on the guinea pig cochlea

    OpenAIRE

    Yamano, Takafumi; Higuchi, Hitomi; Nakagawa, Takashi; Morizono, Tetsuo

    2015-01-01

    Background To evaluate the ototoxicity of acetic acid solutions. Methods Compound action potentials (CAPs) of the eighth nerve were measured in guinea pigs before and after the application of acetic acid in the middle ear cavity. The pH values of the acetic acid solutions were pH 3.0, 4.0, and 5.0, and the application times were 30 min, 24 h, and 1 week. Results Acetic acid solution (pH 3.0, N = 3) for 30 min caused no significant elevation in CAP threshold at 4 kHz, but a significant elevati...

  7. 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.

  8. Space weather impact on the equatorial and low latitude F-region ionosphere over India

    OpenAIRE

    Dabas, R. S.; Das, R M; V. K. Vohra; Devasia, C. V.

    2006-01-01

    For a detailed study of the space weather impact on the equatorial and low latitude F-region, the ionospheric response features are analysed during the periods of three recent and most severe magnetic storm events of the present solar cycle which occurred in October and November 2003, and November 2004. The F-layer base height (h'F), peak height (hmF2) and critical frequency (foF2) data, from Trivandrum, an equatorial station and D...

  9. 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.

  10. The physical and theoretical basis of solar-terrestrial relationships 2. Non-equatorial locations

    International Nuclear Information System (INIS)

    The basic formulations presented in Part 1 of this series (hereinafter simply referred to as ''Paper 1'') are modified in order to mathematically represent the expected solar-terrestrial influences in non-equatorial regions. Analysis and interpretation of these formulations lead to the establishment of several new periodicities as well as other features associated with the non-equatorial atmosphere. Besides, we show through suitable examples that the physical processes that cause and influence some previously observed climatic and upper atmospheric variations in temperate and polar regions are easily deduced from our formulations. (author). 35 refs

  11. Biochemical properties of the bromodeoxyuridine-induced guinea pig virus.

    Science.gov (United States)

    Michalides, R; Schlom, J; Dahlberg, J; Perk, K

    1975-10-01

    The biophysical and biochemical properties of the virus particles released by guinea pig embryo cells treated with 5-bromo-2'-deoxyuridine (BUdR) have been compared to those of the B-type mouse mammary tumor virus (MMTV) and the C-type Rauscher murine leukemia virus. The high-molecular-weight (60 to 70S) RNA of the BUdR-induced guinea pig virus (GPV) has a molecular weight of 8 X 106 when measred by mixed agarose polyacylamide gel electrophoresis. The virus particles isolated from the tissue culture medium of BUdR-induced guniea pig cells have the following properties in common with MMTV: (i) a buoyant density of 1.18 g/ml in sucrose and 1.21 g/ml in CsCl, and (ii) a DNA polymerase that prefers Mg2+ over Mn2+ in an assay using the synthetic template poly(rC):oligo(dG). No nucleic acid sequence homology between GPV RNA and the viral RNAs of the MMTV, murine leukemia virus, hamster sarcoma virus, or Mason-Pfizer monkey virus could be observed in a competition hybridization assay using the radioactive-labeled GPV 60 to 70S RNA. By this same competition by hybridization assay the frequency of GPV proviral sequences was estimated to be at least 83 per haploid cellular genome of guniea pig cells. No nucleic acid sequences related to be GPV RNA were detected in the DNA of normal tissues of mice, rats, cats, dogs, baboons, or humans by direct RNA-DNA hybridization using radioactive GPV60 to 70S RNA. PMID:51933

  12. 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

  13. Community perception and role in prevention of Guinea worm disease.

    Science.gov (United States)

    Omar, M A; Sufi, Q M; Gamba-Osiga, A

    1993-01-01

    In Kitgum district of northern Uganda in 1992, natural group and focus group discussions and key informant interviews were conducted to examine the knowledge, attitudes, practices, and beliefs of the people concerning Guinea Worm disease (GW disease) and its transmission, prevention, and treatment. Most people could describe the cause and treatment of Coo (local name of GW disease). More than 58% thought dirty or bad water was the main cause of Coo. 63.2% believed that drinking contaminated water was the cause. 13.1% did not know the cause of GW disease. Few people clearly understood how GW is transmitted. People received treatment from the nearest health unit (42%), traditional healers (34%), self-medication (16%), and drug shops (8%). 55.3% of key informants believed that Coo cases had increased. The perceived reasons for the increase were drinking dirty water (42.8%), migration (38.1%), no medicine (9.5%), and increased population (4.8%). Suggestions for community action to halt transmission of GW included provision of safe water, educating each other, boiling water, and filtering water. The community perceived that the government and nongovernmental organizations could drill new boreholes, bring in medications, repair broken boreholes, protect water sources, and provide education to stop the spread of GW disease. Water sources were shallow wells, streams, rivers, valley dams, and boreholes. 77.3% of boreholes did not work. Most other water sources were inadequately protected from GW infestation. Some community members perceived boiling water as tedious and difficult. Most people thought that there was nothing or little they could do to prevent contamination of water sources. Few had heard health education messages about Guinea Worm disease. Many people wanted the use of plays, drama, and videos in villages to communicate GW prevention messages. PMID:7516675

  14. Pharmacokinetics of activated protein C in guinea pigs

    International Nuclear Information System (INIS)

    Protein C is a vitamin K-dependent zymogen of the serine protease, activated protein C (APC), an important regulatory enzyme in hemostasis. In view of the potential of human APC as an anticoagulant and profibrinolytic agent, the pharmacokinetics and tissue distribution of APC were studied in guinea pigs. The plasma elimination of a trace dose of 125I-APC was biphasic following an initial rapid elimination of approximately 15% of the injected dose within 1 to 2 minutes. This rapid removal of 125I-APC from the circulation was found to be a result of an association with the liver regardless of the route of injection. Essentially identical results were obtained with active site-blocked forms of APC generated with either diisopropylfluorophosphate or D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone, which indicates that the active site was not essential for the liver association. Accumulation of all three forms of APC in the liver peaked at 30 minutes and then declined as increasing amounts of degraded radiolabeled material appeared in the gastrointestinal tract and urine. Removal of the gamma-carboxyglutamic acid (gla) domain of diisopropylphosphoryl-APC resulted in a 50% reduction in the association with liver and an accumulation in the kidneys. Protein C and protein S were cleared from the circulation at rates approximately one-half and one-fourth, respectively, that of APC. Both in vitro and in vivo, APC was found to form complexes with protease inhibitors present in guinea pig plasma. Complex formation resulted in a more rapid disappearance of the enzymatic activity of APC than elimination of the protein moiety. These findings indicate two distinct mechanisms for the elimination of APC. One mechanism involves reaction with plasma protease inhibitors and subsequent elimination by specific hepatic receptors. (Abstract Truncated)

  15. Blast cells transfer experimental hypersensitivity pneumonitis in guinea pigs

    International Nuclear Information System (INIS)

    We previously demonstrated that experimental hypersensitivity pneumonitis (HP) can be transferred by lymph node cells (LNC) cultured in vitro with antigen. The purpose of this study was to identify the cells responsible for transfer and to determine if pulmonary cells can transfer HP. We cultured LNC from sensitized Strain 2 guinea pigs with a soluble extract of Micropolyspora faeni for 72 h, separated lymphoblasts from small lymphocytes, and transferred both subpopulations intravenously to syngeneic recipients. We also transferred irradiated lymphoblasts (1,500 rads), macrophage-depleted, lymphoblast-enriched populations, and pulmonary cells either without culture or after culture with M. faeni. Control animals received an equal volume of medium. All recipient animals were challenged intratracheally (i.t.) with M. faeni 48 h after the cell transfer, and they were killed 4 days after i.t. challenge. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. This measurement was reproducible (r = 0.95 for duplicate measurements, n = 55). All guinea pigs were maintained in HEPA-filtered air. There was a low level of pulmonary response to an i.t. challenge of M. faeni in animals that received medium. Animals that received pulmonary cells, either cultured or noncultured, did not differ from those in the control group. There was a substantial increase (p less than 0.01) in the extent of pulmonary abnormalities in the recipients of the lymphoblast population, with significant correlation (r = 0.87, p less than 0.01) between the number of lymphoblasts transferred and the extent of pulmonary abnormalities

  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. Effect of Montelukast on bradykinin-induced contraction of isolated tracheal smooth muscle of guinea pig

    OpenAIRE

    Noor, A.; Najmi, M.H.; Bukhtiar, S.

    2011-01-01

    Aim: To explore the effect of montelukast on bradykinin-induced tracheal smooth muscle contraction of isolated guinea pig trachea. Study Design: To study the effect of bradykinin in the absence and in the presence of montelukast on the isolated tracheal smooth muscle of a guinea pig pretreated with indomethacin (10 -6 M), phentolamine (10 -5 M), and propranalol (10 -6 M), to eliminate the effect of endogenous prostaglandins and catecholamines. The trachealis smooth muscle activity was re...

  18. 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 ...

  19. A Pilot Study of Uterine Artery Embolization with Tris-Acryl Gelatin Microspheres in Guinea Pigs

    International Nuclear Information System (INIS)

    Objective: This study was designed to establish guinea pigs as an animal model for uterine artery embolization (UAE) with tris-acryl gelatin microspheres (TAGM). Methods: Twenty-five female adult guinea pigs were randomly divided into two groups, including a uterine artery casting mould group (n = 10) and a UAE group (n = 15). Pelvic angiography and vascular casting mould were performed in the first group. The anatomical characters of the pelvic cavity in guinea pigs were described. In the second group, the technical feasibility of performing UAE with TAGM in guinea pigs was investigated. The histopathological slides of the uterus of guinea pigs after UAE were examined to inspect the outcomes of UAE. Results: The uterine artery springs from the internal iliac artery, ascends tortuously along the cervix, and gives off vertically 8–10 branches to the cervix uteri and uterine horns. The diameters of the trunk of the uterine artery and its first branch were 0.32 ± 0.027 mm and 0.14 ± 0.01 mm, respectively. For UAE animals, the dosages of 40–120 and 100–300 μm TAGM were 0.033 ± 0.003 ml and 0.015 ± 0.002 ml, respectively. On histopathological slides, embosphere particles were found in the first branches of the uterine artery, the subserous arteries, and the intramural arteries. Inflammatory reactions in the uterus were common in guinea pigs after UAE. Local or dispersed areas of necrosis in uterus also were observed in a few guinea pigs. Conclusions: Guinea pigs are an appropriate and feasible model for UAE with TAGM.

  20. 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 ...

  1. 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...

  2. Malaria vector populations across ecological zones in Guinea Conakry and Mali, West Africa

    OpenAIRE

    Coulibaly, Boubacar; Kone, Raymond; Barry, Mamadou S.; Emerson, Becky; Coulibaly, Mamadou B.; Niare, Oumou; Beavogui, Abdoul H.; Traore, Sekou F; Vernick, Kenneth D.; Riehle, Michelle M.

    2016-01-01

    Background Malaria remains a pervasive public health problem in sub-Saharan West Africa. Here mosquito vector populations were explored across four sites in Mali and the Republic of Guinea (Guinea Conakry). The study samples the major ecological zones of malaria-endemic regions in West Africa within a relatively small distance. Methods Mosquito vectors were sampled from larval pools, adult indoor resting sites, and indoor and outdoor human-host seeking adults. Mosquitoes were collected at sit...

  3. Molecular Cloning, Expression, and In Silico Structural Analysis of Guinea Pig IL-17

    OpenAIRE

    Dirisala, Vijaya R.; Jeevan, Amminikutty; Ramasamy, Suresh K.; McMURRAY, David N.

    2013-01-01

    Interleukin-17A (IL-17A) is a potent proinflammatory cytokine and the signature cytokine of Th17 cells, a subset which is involved in cytokine and chemokine production, neutrophil recruitment, promotion of T cell priming, and antibody production. IL-17 may play an important role in tuberculosis and other infectious diseases. In preparation for investigating its role in the highly relevant guinea pig model of pulmonary tuberculosis, we cloned guinea pig IL-17A for the first time. The complete ...

  4. Effects of diet and genetics on Mycobacterium bovis BCG vaccine efficacy in inbred guinea pigs.

    OpenAIRE

    Cohen, M K; Bartow, R A; Mintzer, C L; McMurray, D. N.

    1987-01-01

    Strain 2 and strain 13 guinea pigs were vaccinated with Mycobacterium bovis BCG and placed on low-protein or protein-adequate diets. Five weeks later all animals were infected by the respiratory route with virulent Mycobacterium tuberculosis H37Rv organisms. Four weeks postchallenge, guinea pigs were skin tested with purified protein derivative and sacrificed. Protein deficiency resulted in significant reductions in body weight and thymus weight and in an impairment in the ability to control ...

  5. 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....

  6. The New Guinea species of Pandanus section Maysops St. John (Pandanaceae)

    OpenAIRE

    Stone, Benjamin C.

    1992-01-01

    Species of Pandanus belonging to section Maysops St. John [this section is presently classified under subgenus Lophostigma (Brongn.) Stone], about 16 in all, occur in New Guinea, the adjacent Moluccas, the Bismarck Archipelago, the Solomon Islands, and Northern Queensland, Australia. The majority (11) of the species are found in, and mostly limited to, New Guinea. Here these 11 species are reviewed, a key for identification is presented, and information on synonymous names, distribution, and ...

  7. "Stuck in thorns". The effects of power on Liberian refugees in Guinea

    OpenAIRE

    Collins, Henry Ahorttor

    2013-01-01

    Abstract This thesis is about refugees who fled from Liberia to Guinea to join the miserable sea of humanity" (Malkki 1996) from January 1990 when the Charles Taylor led a rebel war that began in December 1989. Essentially, this thesis focuses on analyzing how first the bureaucratic power exercised by UNHCR and CNISR, as well as second, everyday power by Guinean majority affect Liberian refugees in Guinea, and how the refugees themself have found ways to address the challenges they meet. ...

  8. Serial histopathological changes in irradiated guinea pig lung receiving conventional fractionated and hyperfractionated irradiation

    International Nuclear Information System (INIS)

    The purpose of this study is to determine serial histopathological differences in guinea pig lungs receiving the same total dose as clinically used between conventional fractionated and hyperfractionated irradiation. The guinea pigs received 80 Gy in 40 daily fractions of 2 Gy each (conventional fractionation), 80 Gy in 80 fractions of 1 Gy each twice a day (hyperfractionation), 81 Gy in 27 daily fractions of 3 Gy each (conventional fractionation), or 81 Gy in 54 fractions of 1.5 Gy each twice a day (hyperfractionation). We evaluated the histopathological changes of irradiated guinea pig lungs at 1, 2, 3, 6, 9, and 12 months after irradiation. The guinea pig lungs that received 81 Gy in 27 daily fractions showed histopathological changes of inflammation including formation of lymph follicles after 6 months. The lungs which received 81 Gy in 54 fractions showed similar but slightly less pronounced changes than those that received 81 Gy in 27 daily fractions. The guinea pig lungs of other groups showed no histopathological changes during the observation period. In hyperfractionated irradiation the damage to the guinea pig lung is quantitatively less than that occurring as a result of conventional fractionated irradiation of the same total dose. (author)

  9. Effect of some non-steroidal anti-inflammatory drugs on ouabain-induced arrhythmias in guinea-pigs.

    OpenAIRE

    Tripathi, R. M.; Kaushal, R.

    1988-01-01

    1. Effects of some non-steroidal anti-inflammatory drugs on ouabain-induced arrhythmias in guinea-pigs were studied. 2. Ventricular premature beats, ventricular fibrillation and cardiac arrest were induced in pentobarbitone-anaesthetized guinea-pigs by a slow intravenous infusion of ouabain. 3. Aspirin and indomethacin were found to accord a significant protection to the guinea-pigs against arrhythmias whereas ketoprofen was found to be ineffective. 4. It is concluded that the protective effe...

  10. 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...

  11. 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...

  12. Immunological relationships of an endogenous guinea pig retrovirus with prototype mammalian type B and type D retroviruses.

    OpenAIRE

    Dahlberg, J E; Tronick, S R; Aaronson, S A

    1980-01-01

    A retrovirus endogenous to guinea pig cells was earlier shown to be morphologically similar to type B and type D prototype retroviruses. Molecular hybridization techniques were used to show that guinea pig virus nucleotide sequences are endogenous to both domestic (Cavia porcellus) and indigenous (Cavia aperea) guinea pigs, but cannot be detected in the DNA of either other hystricomorph rodents or other mammals tested. Using radioimmunological techniques designed to detect interspecies relati...

  13. Pharmacological investigation into the effects of histamine and histamine analogues on guinea-pig and rat colon in vitro.

    OpenAIRE

    M. J. Aguilar; Morales-Olivas, F. J.; Rubio, E.

    1986-01-01

    The effects of histamine and specific histamine agonists has been examined on isolated longitudinal colon strips of guinea-pig and rat. Histamine and 2-pyridyl-ethylamine but not 4 methylhistamine produced a concentration-related contractile response in the guinea-pig colon. The H1-antagonist clemizole antagonized competitively the effect of histamine but the H2-antagonist ranitidine did not modify the dose-response curve to histamine in the guinea-pig colon. Atropine, hexamethonium, prazosin...

  14. 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.

  15. 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

  16. 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...

  17. Electrical slow waves and tone of guinea-pig isolated trachealis muscle: effects of drugs and temperature changes

    OpenAIRE

    Small, Roger C.

    1982-01-01

    1 Simultaneous recordings of electrical and mechanical activity have been made from guinea-pig isolated trachealis muscle. Electrical activity was recorded both by extracellular and intracellular techniques.

  18. Establishment of a leptospirosis model in guinea pigs using an epicutaneous inoculations route

    Directory of Open Access Journals (Sweden)

    Zhang Yan

    2012-01-01

    Full Text Available Abstract Background Leptospires are presumed to enter their host via small abrasions or breaches of the skin. The intraperitoneal route, although commonly used in guinea pig and hamster models of leptospirosis, does not reflect conditions encountered during natural infection. The aim of this study is to develop a novel leptospirosis guinea pig model through epicutaneous route and to elucidate the pathogenesis of leptospirosis in experimental guinea pigs by comparing the data from other studies using different infection routes. Methods The guinea pigs were inoculated with 5 × 108 Leptospira interrogans strain Lai onto either shaved-only or abraded skin. The guinea pigs were sacrificed at 2, 8, 24, 48, 72, 96 and 144 h post-infection (p.i. followed by harvest of the lungs, liver, kidneys, spleen, and the skin around the inoculated sites for further examinations. Hematoxylin and eosin (HE staining and electron microscopy were used to detect the pathologic changes. Real time PCR and immunohistochemistry staining were performed to detect dynamic distribution of leptospires in blood and tissues, respectively. Results In the guinea pigs with abraded skin inoculations, leptospires were detected in blood as early as 2 h post infection (p.i. and then disseminated to the liver, lungs and kidneys of almost all animals within 96 h p.i.. Leptospires were also detected engulfed in the swelling vascular endothelial cells and were frequently aggregated around the capillaries in the dermis and subcutaneous tissue under the inoculated site. For the guinea pigs with abraded skin inoculations, hemorrhage at the dermis around the inoculated site was found before the appearance of internal organs hemorrhage, severe lesions such as hemorrhages in the lungs, nephritis, jaundice, haematuria were also observed, and two of seven guinea pigs died at 144 h p.i. while no lesions and leptospires were detected in the shaved-only guinea pigs using the same dose of strain Lai

  19. 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.

  20. 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.

    enrichments’ of inorganic nutrients was observed relative to 20 m in the mixed layer. Lowest oxygen levels of 19 mu M at 3 degrees N in the euphotic zone indicate mixing of low oxygen high salinity Arabian Sea waters with the equatorial Indian Ocean...

  1. Importance of Large-Scale Wave Structure to Equatorial Spread F

    Science.gov (United States)

    Tsunoda, R. T.

    2008-12-01

    There is mounting evidence that large-scale wave structure (LSWS) is a more direct precursor of equatorial spread F (ESF) than the post-sunset rise (PSSR) of the equatorial F layer. Unambiguous experimental evidence, though limited, come from measurements by ALTAIR, a fully steerable incoherent-scatter radar, in situ measurements by low-altitude satellites in low-inclination orbits (AE-E, San Marco D), and total electron content measurements using satellites in low-inclination orbits. Less direct evidence is contained in seemingly extraneous traces in equatorial ionograms, which appear to be associated with LSWS and ESF. Clearly, a demonstration that these traces are indeed a direct consequence of LSWS is pivotal because such a demonstration would allow use of the extensive database of equatorial ionograms that exists to argue conclusively that LSWS is a central player in ESF generation. A demonstration of this kind will be presented, together with a description of experiments proposed for the Pacific sector, which involve the C/NOFS satellite, and how they will increase substantially our understanding of LSWS and ESF.

  2. 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...

  3. 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)

  4. 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.

  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. The magnetic field of the equatorial magnetotail: AMPTE/CCE observations at R E

    International Nuclear Information System (INIS)

    The Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer (AMPTE/CCE) magnetic field experiment has provided extensive measurements of the vector field near the equatorial plane in the inner magnetotail. Taillike distortions from the dipole field direction may reach 80 degree near the AMPTE/CCE apogee of 8.8 RE. The Bz (north-south) field component in dipole coordinates was always positive within 0.5 RE of the equatorial current sheet, indicating that neutral lines were never seen inside of 8.8 RE. South of -0.5 RE, Bz values are sometimes southward due to extremely taillike fields and the southward tilt of the tail in dipole coordinates during northern hemisphere winter. Fields are most taillike near midnight and during times of high Kp. At 8.5 RE the equatorial field magnitude depressions are roughly half the dipole field strength of 51 nT. The equatorial crossing points of midnight field lines are computed using the observed field depressions. Mapping auroral boundaries along these distorted field lines indicates that most auroral arcs map to magnetospheric locations beyond 12 RE, but that low latitude arcs may well occur on closed field lines earthward of this distance. Evidence is found confirming that a cross-tail field component in the inner magnetotail is related to the interplanetary sector structure but, contrary to earlier results, the effect is found to be larger during geomagnetically disturbed times

  7. 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.

  8. 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

  9. Anomalous circulation in the eastern equatorial Indian Ocean during southwest monsoon of 1994

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A; Murty, V.S.N; Babu, M.T.; Gopinathan, C.K.; Charyulu, R.J.K.

    Geostrophic circulation derived from hydrographic data collected during July-August, 1994 along 80, 84 and 88E between 5N and 3S latitudinal belt in the eastern equatorial Indian Ocean is presented. A broad westward flow north of the equator...

  10. 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.

  11. Equatorial anomaly variability as a function of the local time and the longitude

    International Nuclear Information System (INIS)

    The equatorial anomaly dynamics is very difficult to study due to necessity of its monitoring in space (latitude-longitude) and local time simultaneously. This task is impossible for the single-point measurements, and only the satellite technology may help. The present paper is devoted to the preliminary analysis of the equatorial anomaly dynamics combining two techniques - the topside sounding and GPS TEC measurements. The topside sounding gives the unique opportunity to build the global structure of the equatorial anomaly for the fixed local time (LT-maps) and to reveal the longitudinal variations, while the chains of GPS receivers along the meridian permit to study the latitudinal variations of TEC in local time. Two meridional chains of GPS receivers were selected: at 115 deg. E and 70 deg. W longitudes. Combining of two technologies makes it possible to obtain three-dimensional global dynamics of the equatorial anomaly. The paper demonstrates the power of the technique itself while the more detailed and comprehensive analysis will be continued in the following papers. (author)

  12. Intensities and spatiotemporal variability of equatorial noise emissions observed by the Cluster spacecraft

    Czech Academy of Sciences Publication Activity Database

    Němec, F.; Santolík, Ondřej; Hrbáčková, Zuzana; Cornilleau-Wehrlin, N.

    2015-01-01

    Roč. 120, č. 3 (2015), s. 1620-1632. ISSN 2169-9380 R&D Projects: GA MŠk(CZ) LH11122 Institutional support: RVO:68378289 Keywords : equatorial noise * magnetosonic waves Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/2014JA020814/full

  13. A study of the equatorial noise gyroharmonics frequency values with Cluster wave data

    Czech Academy of Sciences Publication Activity Database

    Cornilleau-Wehrlin, N.; Sochorová, Zuzana; Santolík, Ondřej; Pickett, J.; Canu, P.; Grison, Benjamin

    Venice: CAA - ESA, 2015. s. 46. [Cluster Workshop /25./. 12.10.2015–16.10.2015, Venice] Institutional support: RVO:68378289 Keywords : equatorial magnetosonic waves * cluster analysis Subject RIV: BL - Plasma and Gas Discharge Physics http://caa.estec.esa.int/images/cluster_workshops/25/Cluster25_abstract_book4.pdf

  14. 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...

  15. 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.

  16. 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.

  17. Long range forecasting of summer monsoon rainfall from SST in the central equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Murthy, T.V.R.

    pressure change at Bombay during Winter to pre-monsoon and Sea Surface Temperature (SST) over Pacific and Indian Ocean regions. The relationship between SST in the Central Equatorial Indian Ocean (CEIO) and all India Summer Monsoon Rainfall using the data...

  18. 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...

  19. Internal waves and Equatorial dynamics: an observational study in the West Atlantic Ocean

    Science.gov (United States)

    Rabitti, Anna; Maas, Leo R. M.; van Haren, Hans; Gerkema, Theo

    2013-04-01

    Internal waves present several fascinating aspects of great relevance for geo- and astro-physical fluid dynamics. These waves are supported by all kinds of stratified and rotating fluids, such as, for example, our ocean, atmosphere, a planet fluid core or a star. In a non linear regime, because of their oblique propagation, they are thought to play a key role in diapycnal mixing, as well as in angular momentum mixing. Unfortunately, a complete analytical description of internal waves in arbitrarily shaped enclosed domains is still an ongoing challenge. On the other hand, internal wave energy is observed travelling along rays, whose behaviour can be traced and whose reflections off the container's boundaries appears crucial in producing phenomena such as focussing of wave energy onto specific trajectories (attractors), and in triggering localized instabilities. Ray tracing studies have shown that equatorial regions of stratified and/or rotating spherical shells are likely affected by these features, being the place where the simplest shaped and most energetic attractors occur. In this study we aim to investigate the possible presence and role of internal wave attractors in determining the equatorial ocean dynamics. Internal wave attractors, observed in laboratory and numerical experiments, have not been observed in Nature, yet. A unique set of observations, collected in the deep Equatorial West Atlantic Ocean, will be used here in order to explore this possibility, the dataset consisting of 1.5 year long time series of current measured acoustically and with current meters moored between 0°and 2°N, at 37°W, off the Brazilian coast. In particular, angular momentum mixing due to internal wave focussing, is explored as a possible mechanism for maintaining the Equatorial Deep Jets. These jets are stacked alternating zonal currents that are ubiquitously observed in all the oceans and whose nature is still largely unknown. Remarkably, jet like structures are also

  20. Electromagnetic coupling between the region-1 and -2 field-aligned currents and the equatorial ionosphere

    International Nuclear Information System (INIS)

    Complete text of publication follows. The convection electric field penetrates to the equatorial ionosphere with no significant shielding during DP2 fluctuation events with periods of 30-60 min (Nishida, JGR, 1968; Kikuchi et al., JGR, 1996; Kobea et al., AG, 1998) and even during storm main phase continuing for several hours (Huang et al., JGR, 2005; JASTP, 2007). On the other hand, shielding becomes effective in 17-20 min during substorm growth phase (Somayajulu et al., GRL, 1987; Kikuchi et al., JGR, 2000), and 1 h during storm main phase (Kikuchi et al., JGR, 2008). Overshielding occurs when the IMF turns northward or the southward IMF decreases during substorms (Kikuchi et al., JGR, 2003) and during storm recovery phase (Kikuchi et al., JGR, 2008). To clarify relative contributions of the convection and shielding electric fields in the low latitude ionosphere, we analyzed equatorial DP2 fluctuation events of 30-60 min periods using magnetometer data, SuperDARN convection maps and electric potentials calculated with the comprehensive ring current model (CRCM) (Fok et al., JGR, 2001). The equatorial DP2 fluctuation was found to be caused by alternating eastward (e-EJ) and westward electrojets (w-EJ) in the equatorial ionosphere, which were caused by the southward and northward IMF, respectively. Using SuperDARN convection maps, we further show that the e-EJ was associated with large-scale two-cell convection vortices, while the w-EJ accompanied reverse flow vortices equatorward of the two-cell vortices. With the aid of the CRCM, we suggest that the reverse flow vortices were associated with the Region-2 field-aligned currents (R2 FACs) that caused overshielding at the equator. Thus, we suggest that the R1 and R2 FACs are connected with the e-EJ and w-EJ, respectively. As a result, the overshielding electric field and current can appear at mid-equatorial latitudes irrespective of the period of fluctuations, when the R1 FAC decreases its intensity. This scenario

  1. The Dependence of the Low-Level Equatorial Easterly Jet on Hadley and Walker Circulations.

    Science.gov (United States)

    Battisti, David S.; Ovens, David D.

    1995-11-01

    How the time-mean Hadley and Walker circulations affect the formation of a low-level equatorial easterly jet is investigated. Experiments are conducted for equinoctial conditions using a general circulation model, the Community Climate Model (CCM1), that includes a Kuo convective scheme and a lower boundary that is specified to be water at a fixed sea surface temperature (SST). Several zonally symmetric SST forcings are used to determine how various Hadley circulations affect the tropical zonal wind field. A zonal wavenumber one equatorial SST anomaly superimposed on a zonally symmetric SST distribution forces a wind field that includes both Hadley and Walker circulations.The Hadley circulation experiments produce equatorial easterlies and low-level jets on the poleward sides of the intertropical convergence zone (ITCZ) 10° to 15° from the equator. In an experiment with a single, dominant off-equatorial ITCZ in the Northern Hemisphere, the Southern Hemisphere jet moves to within 7.5° of the equator; yet none of the Hadley circulation cases produce a low-level easterly jet on the equator because they lack a mechanism to vertically confine the flow.The experiment that includes a zonally overturning cell on the equator produces a low-level equatorial easterly jet in the cold tongue region that is similar to the observed jet over the central to eastern Pacific. That case shows that east of the equatorial warm pool the Walker circulation and its induced Kelvin wave response provide the necessary upper-level westerly flow and subsidence to vertically confine the low-level easterlies into a jet. Spring and fall climatological runs of the CCMI with land surfaces, seasonally varying SSTs and insolation, and a moist convective adjustment scheme support the hypothesis that the Walker circulation provides the vertical confinement necessary to form a low-level equatorial easterly jet in the region east of the equatorial convective center, regardless of the Hadley circulation

  2. 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.

  3. Equatorial and low-latitude ionospheric response due to 2009 sudden stratospheric warming, South American sector.

    Science.gov (United States)

    Fagundes, Paulo Roberto; Gende, Mauricio; De Jesus, Rodolfo; Goncharenko, Larisa; Coster, Anthea; Kavutarapu, Venkatesh; De Abreu, Alessandro; Pillat, ValdirGil; Pezzopane, Michael

    The equatorial and low-latitude ionosphere/thermosphere system is permanently disturbed by waves (MSTIDs, tides, and planetary waves), which are generated in the lower atmosphere or in situ, as well as electric fields and TIDs produced by geomagnetic storm and UV, EUV, and X-ray solar radiation. Until recently it was thought, that during geomagnetic quiet conditions the equatorial and low-latitude F-layer was mainly perturbed by waves that were generated not far away from the observed location or electric fields generated by electroject. On the contrary during geomagnetic storms when the energy sources are in high latitudes the waves (TIDs) travel a very long distance from high latitude to equatorial region and electric fields can be mapped via magnetic field lines. However, recently an unexpected coupling between high latitude, -mid latitude, and -equatorial/low-latitude was discovered during sudden stratospheric warming (SSW). The exploration of all aspects involved in this process must be investigated in order to improve our knowledge about the Earth's atmosphere. This investigation, studies the consequences of the vertical coupling from lower to upper atmosphere during a major Northern Hemisphere sudden stratospheric warming, which took place in January 2009, on the equatorial and low-latitude ionosphere in the Southern Hemisphere. Using 16 ground-based GPS stations over the Brazilian sector, spanning from latitude 2.8N to 30.1S and longitude 62.0W to 37.7W, it was possible to notice that the ionosphere was disturbed by SSW from the Equator to low latitude. The TEC at all 16 stations was severely disturbed during several days after the SSW temperature peak.

  4. Attributing Tropical Cyclogenesis to Equatorial Waves in the Western North Pacific

    Science.gov (United States)

    Schreck, Carl J., III; Molinari, John; Mohr, Karen I.

    2009-01-01

    The direct influences of equatorial waves on the genesis of tropical cyclones are evaluated. Tropical cyclogenesis is attributed to an equatorial wave when the filtered rainfall anomaly exceeds a threshold value at the genesis location. For an attribution threshold of 3 mm/day, 51% of warm season western North Pacific tropical cyclones are attributed to tropical depression (TD)-type disturbances, 29% to equatorial Rossby waves, 26% to mixed Rossby-Gravity waves, 23% to Kelvin waves, 13% to the Madden-Julian oscillation (MJO), and 19% are not attributed to any equatorial wave. The fraction of tropical cyclones attributed to TD-type disturbances is consistent with previous findings. Past studies have also demonstrated that the MJO significantly modulates tropical cyclogenesis, but fewer storms are attributed to the MJO than any other wave type. This disparity arises from the difference between attribution and modulation. The MJO produces broad regions of favorable conditions for cyclogenesis, but the MJO alone might not determine when and where a storm will develop within these regions. Tropical cyclones contribute less than 17% of the power in any portion of the equatorial wave spectrum because tropical cyclones are relatively uncommon equatorward of 15deg latitude. In regions where they are active, however, tropical cyclones can contribute more than 20% of the warm season rainfall and up to 50% of the total variance. Tropical cyclone-related anomalies can significantly contaminate wave-filtered precipitation at the location of genesis. To mitigate this effect, the tropical cyclone-related rainfall anomalies were removed before filtering in this study.

  5. Directions of equatorial noise propagation determined using Cluster and DEMETER spacecraft

    Science.gov (United States)

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

    2013-04-01

    Equatorial noise emissions are electromagnetic waves at frequencies between the proton cyclotron frequency and the lower hybrid frequency routinely observed within a few degrees of the geomagnetic equator at radial distances from about 2 to 6 Re. High resolution data reveal that the emissions are formed by a system of spectral lines, being generated by instabilities of proton distribution functions at harmonics of the proton cyclotron frequency in the source region. The waves propagate in the fast magnetosonic mode nearly perpendicularly to the ambient magnetic field, i.e. the corresponding magnetic field fluctuations are almost linearly polarized along the ambient magnetic field and the corresponding electric field fluctuations are elliptically polarized in the equatorial plane, with the major polarization axis having the same direction as wave and Poynting vectors. We conduct a systematic analysis of azimuthal propagation of equatorial noise. Combined WBD and STAFF-SA measurements performed on the Cluster spacecraft are used to determine not only the azimuthal angle of the wave vector direction, but also to estimate the corresponding beaming angle. It is found that the beaming angle is generally rather large, i.e. the detected waves come from a significant range of directions, and a traditionally used approximation of a single plane wave fails. The obtained results are complemented by a raytracing analysis in order to get a comprehensive picture of equatorial noise propagation in the inner magnetosphere. Finally, high resolution multi-component measurements performed by the low-altitude DEMETER spacecraft are used to demonstrate that equatorial noise emissions can reach altitudes as low as 660 km, and that the observed propagation properties are in agreement with the overall propagation picture.

  6. 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.

  7. Effect of KOB03, a polyherbal medicine, on ovalbumin-induced allergic rhinitis in guinea pigs

    Directory of Open Access Journals (Sweden)

    Jung Hyo Won

    2012-12-01

    Full Text Available Abstract Background KOB03 is a polyherbal medicine that originated from the oriental prescription for the treatment of chronic allergic diseases such as rhinitis and asthma. This study aims to evaluate the effect of KOB03 on ovalbumin (OVA-induced allergic rhinitis (AR in guinea pigs. Methods Hartley guinea pigs were sensitized to OVA by intraperitoneal injection on days 0, 7, and 14 and challenged with intranasal exposure to OVA three times for 7 days after the last sensitization. KOB03 at doses of 200 and 500 mg/kg were orally administrated to guinea pigs once daily during challenge. The serum levels of histamine, OVA-specific immunoglobulin (Ig E, eosinophil cationic protein (ECP and cytokines (TNF-α, IL-4 and IFN-γ in OVA sensitization/challenge-induced AR guinea pigs were measured. We also observed histological changes in nasal tissues of AR guinea pigs by staining with H&E, Periodic acid-Schiff, and toluidine blue. Results The administration of KOB03 at a dose of 500 mg/kg significantly decreased the serum levels of histamine (P = 0.001, OVA-specific IgE (P = 0.0017, ECP (P = 0.008, and TNF-α (P = 0.0003 in OVA-sensitized/challenged guinea pigs compared with controls. KOB03 significantly decreased the serum levels of a Th2 cytokine, IL-4 (P = 0.017, while significantly increasing the levels of a Th1 cytokine, IFN-γ (P = 0.0006 in OVA-sensitized/challenged guinea pigs compared with controls. In addition, KOB03 suppressed the epithelial destruction, goblet cell hyperplasia and eosinophilic infiltration into nasal mucosa associated with AR. Conclusion KOB03 may regulate allergic inflammation in AR by inhibiting nasal damage, the release of allergic mediators and modulating the balance of Th1/Th2 cytokines.

  8. Acute and subchronic dermal toxicity of nanosilver in guinea pig

    Directory of Open Access Journals (Sweden)

    Arbabi Bidgoli S

    2011-04-01

    Full Text Available M Korani1, SM Rezayat1,2,4, K Gilani3, S Arbabi Bidgoli4, S Adeli11Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences; 2Department of Nanotechnology, Faculty of Advanced Sciences and Technology in Medicine, Tehran University of Medical Sciences; 3Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences; 4Department of Toxicology & Pharmacology, Faculty of Pharmacy, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS, Tehran, IranAbstract: Silver has been used as an antimicrobial agent for a long time in different forms, but silver nanoparticles (nanosilver have recently been recognized as potent antimicrobial agents. Although nanosilver is finding diverse medical applications such as silver-based dressings and silver-coated medical devices, its dermal and systemic toxicity via dermal use has not yet been identified. In this study, we analyzed the potential toxicity of colloidal nanosilver in acute and subchronic guinea pigs. Before toxicity assessments, the size of colloidal nanosilver was recorded in sizes <100 nm by X-ray diffraction and transmission electron microscopy. For toxicological assessments, male guinea pigs weighing 350 to 400 g were exposed to two different concentrations of nanosilver (1000 and 10,000 µg/mL in an acute study and three concentrations of nanosilver (100, 1000, and 10,000 µg/mL in a subchronic study. Toxic responses were assessed by clinical and histopathologic parameters. In all experimental animals the sites of exposure were scored for any type of dermal toxicity and compared with negative control and positive control groups. In autopsy studies during the acute test, no significant changes in organ weight or major macroscopic changes were detected, but dose-dependent histopathologic abnormalities were seen in skin, liver, and spleen of all test groups. In addition, experimental animals subjected to subchronic tests showed greater

  9. "Training by Papua New Guinea Women, for Papua New Guinea Women": Lessons from the Development of a Co-Constructed Course for Women Smallholder Farmers

    Science.gov (United States)

    Pamphilon, Barbara; Mikhailovich, Katja; Chambers, Barbara

    2014-01-01

    This article examines the lessons from a collaborative project that worked with women agricultural leaders in Papua New Guinea. The project sought to build the capacity of these leaders as trainers in a way that would enable the development of a sustainable community of practice and worked within a critical and place-based pedagogy underpinned by…

  10. 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.

  11. 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

  12. Wild genius - domestic fool? Spatial learning abilities of wild and domestic guinea pigs

    Directory of Open Access Journals (Sweden)

    Sachser Norbert

    2010-03-01

    Full Text Available Abstract Background Domestic animals and their wild relatives differ in a wide variety of aspects. The process of domestication of the domestic guinea pig (Cavia aperea f. porcellus, starting at least 4500 years ago, led to changes in the anatomy, physiology, and behaviour compared with their wild relative, the wild cavy, Cavia aperea. Although domestic guinea pigs are widely used as a laboratory animal, learning and memory capabilities are often disregarded as being very scarce. Even less is known about learning and memory of wild cavies. In this regard, one striking domestic trait is a reduction in relative brain size, which in the domesticated form of the guinea pig amounts to 13%. However, the common belief, that such a reduction of brain size in the course of domestication of different species is accomplished by less learning capabilities is not at all very well established in the literature. Indeed, domestic animals might also even outperform their wild conspecifics taking advantage of their adaptation to a man-made environment. In our study we compared the spatial learning abilities of wild and domestic guinea pigs. We expected that the two forms are different regarding their learning performance possibly related to the process of domestication. Therefore wild cavies as well as domestic guinea pigs of both sexes, aged 35 to 45 days, were tested in the Morris water maze to investigate their ability of spatial learning. Results Both, wild cavies and domestic guinea pigs were able to learn the task, proving the water maze to be a suitable test also for wild cavies. Regarding the speed of learning, male as well as female domestic guinea pigs outperformed their wild conspecifics significantly. Interestingly, only domestic guinea pigs showed a significant spatial association of the platform position, while other effective search strategies were used by wild cavies. Conclusion The results demonstrate that domestic guinea pigs do not at all

  13. Unique human immune signature of Ebola virus disease in Guinea.

    Science.gov (United States)

    Ruibal, Paula; Oestereich, Lisa; Lüdtke, Anja; Becker-Ziaja, Beate; Wozniak, David M; Kerber, Romy; Korva, Miša; Cabeza-Cabrerizo, Mar; Bore, Joseph A; Koundouno, Fara Raymond; Duraffour, Sophie; Weller, Romy; Thorenz, Anja; Cimini, Eleonora; Viola, Domenico; Agrati, Chiara; Repits, Johanna; Afrough, Babak; Cowley, Lauren A; Ngabo, Didier; Hinzmann, Julia; Mertens, Marc; Vitoriano, Inês; Logue, Christopher H; Boettcher, Jan Peter; Pallasch, Elisa; Sachse, Andreas; Bah, Amadou; Nitzsche, Katja; Kuisma, Eeva; Michel, Janine; Holm, Tobias; Zekeng, Elsa-Gayle; García-Dorival, Isabel; Wölfel, Roman; Stoecker, Kilian; Fleischmann, Erna; Strecker, Thomas; Di Caro, Antonino; Avšič-Županc, Tatjana; Kurth, Andreas; Meschi, Silvia; Mély, Stephane; Newman, Edmund; Bocquin, Anne; Kis, Zoltan; Kelterbaum, Anne; Molkenthin, Peter; Carletti, Fabrizio; Portmann, Jasmine; Wolff, Svenja; Castilletti, Concetta; Schudt, Gordian; Fizet, Alexandra; Ottowell, Lisa J; Herker, Eva; Jacobs, Thomas; Kretschmer, Birte; Severi, Ettore; Ouedraogo, Nobila; Lago, Mar; Negredo, Anabel; Franco, Leticia; Anda, Pedro; Schmiedel, Stefan; Kreuels, Benno; Wichmann, Dominic; Addo, Marylyn M; Lohse, Ansgar W; De Clerck, Hilde; Nanclares, Carolina; Jonckheere, Sylvie; Van Herp, Michel; Sprecher, Armand; Xiaojiang, Gao; Carrington, Mary; Miranda, Osvaldo; Castro, Carlos M; Gabriel, Martin; Drury, Patrick; Formenty, Pierre; Diallo, Boubacar; Koivogui, Lamine; Magassouba, N'Faly; Carroll, Miles W; Günther, Stephan; Muñoz-Fontela, César

    2016-05-01

    Despite the magnitude of the Ebola virus disease (EVD) outbreak in West Africa, there is still a fundamental lack of knowledge about the pathophysiology of EVD. In particular, very little is known about human immune responses to Ebola virus. Here we evaluate the physiology of the human T cell immune response in EVD patients at the time of admission to the Ebola Treatment Center in Guinea, and longitudinally until discharge or death. Through the use of multiparametric flow cytometry established by the European Mobile Laboratory in the field, we identify an immune signature that is unique in EVD fatalities. Fatal EVD was characterized by a high percentage of CD4(+) and CD8(+) T cells expressing the inhibitory molecules CTLA-4 and PD-1, which correlated with elevated inflammatory markers and high virus load. Conversely, surviving individuals showed significantly lower expression of CTLA-4 and PD-1 as well as lower inflammation, despite comparable overall T cell activation. Concomitant with virus clearance, survivors mounted a robust Ebola-virus-specific T cell response. Our findings suggest that dysregulation of the T cell response is a key component of EVD pathophysiology. PMID:27147028

  14. Antitussive activity of iodo-resiniferatoxin in guinea pigs

    Science.gov (United States)

    Trevisani, M; Milan, A; Gatti, R; Zanasi, A; Harrison, S; Fontana, G; Morice, A; Geppetti, P

    2004-01-01

    Background: Iodo-resiniferatoxin (I-RTX) has recently been described as an ultra potent antagonist of the transient receptor potential vanilloid-1 (TRPV1). Methods: The ability of I-RTX to inhibit cough induced by inhalation of two putative TRPV1 stimulants (capsaicin and citric acid) was tested in non-anaesthetised guinea pigs. Results: Pretreatment with I-RTX either intraperitoneally (0.03–0.3 µmol/kg) or by aerosol (0.1–3 µM) reduced the number of coughs produced by inhalation of citric acid (0.25 M) and capsaicin (30 µM) in a dose dependent manner. Capsazepine (CPZ) also reduced citric acid and capsaicin induced cough, but the activity of I-RTX was 10–100 times more potent than CPZ in all the experimental conditions tested. Conclusions: I-RTX is a novel and potent antitussive drug which inhibits cough mediated by agents possibly acting via TRPV1 activation. PMID:15333853

  15. Epidermal cell proliferation in guinea pigs with experimental dermatophytosis

    Energy Technology Data Exchange (ETDEWEB)

    Tagami, H.

    1985-08-01

    To elucidate the mechanisms underlying the self-healing process of experimental dermatophytosis produced in guinea pigs by an occlusive method with Trichophyton mentagrophytes, epidermal proliferative activity was evaluated by the in vivo tritiated thymidine-labeling technique performed at various intervals after the first and second infections. Determination of labeling indices disclosed that an increased epidermal proliferation correlated well with the severity of inflammatory changes, i.e., a peak activity was noted after 10 days in primary infection and at 2 days in reinfection, respectively, and was followed by subsequent spontaneous lesion clearance after 10 days. Application of a heat-killed spore suspension produced inflammatory changes with enhanced epidermopoiesis, similar to those induced by reinoculation of living spores, only in immune animals. The present results indicate that the dermatitic changes occurring in experimental dermatophytosis increase epidermopoiesis which facilitates elimination of the fungus from the stratum corneum and that host immune activity, particularly contact sensitivity to fungal antigen, exerts a crucial role to induce these changes.

  16. Placentophagy in wild chimpanzees (Pan troglodytes verus) at Bossou, Guinea.

    Science.gov (United States)

    Fujisawa, Michiko; Hockings, Kimberley J; Soumah, Aly Gaspard; Matsuzawa, Tetsuro

    2016-04-01

    Despite intensive observation of nonhuman great apes during long-term field studies, observations of great ape births in the wild are rare. Research on wild chimpanzees (Pan troglodytes verus) at Bossou in the Republic of Guinea has been ongoing for 35 years, yet chimpanzee parturitions have been observed on only two occasions. Here we provide information regarding both chimpanzee births, with detailed information from the close observation of one. During this birth, the mother built a day nest in a tree before parturition. After giving birth, the mother consumed the placenta, and the other chimpanzees in her party gathered near her and her neonate. However, she did not share the placenta, and consumed it all herself. In the second observation, the mother also built a nest in a tree and subsequently gave birth. Thereafter, she shared the placenta with some individuals and consumed part of the placenta herself. Although maternal placentophagy is a ubiquitous behavior among the majority of non-human primates, observations of placenta sharing by wild primates are infrequent, and the proximate and ultimate explanations for the behavior remain unclear. PMID:26769192

  17. Sustainability of Land Groups in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Lepani Karigawa

    2016-05-01

    Full Text Available This paper consists of a review of existing literature relating to Incorporated Land Groups in Papua New Guinea (PNG, followed by a case study of two urban incorporated land groups (ILGs in the city of Lae. The paper is an attempt at assessing the sustainability of ILGs in the country. The challenges facing the ILGs have heightened public fears that the land groups may not be sustainable. Based on the argument in previous studies that the ILGs are not sustainable, the paper used primary data from two separate questionnaire surveys of randomly selected ILG landowners (including legal settlers and ILG stakeholders to investigate the problem. The combined sample size of 129 respondents (32.7% was representative of the total ILG population, while a total of 25 indicators were used to test the respondents’ perceptions regarding ILG sustainability. Findings reveal that only one of the indicators received the positive support of the stakeholders, while no indicator was supported by the landowners. This suggests that the ILGs in PNG are not sustainable legal entities. This dilemma is a consequence of the challenges facing the ILGs, including the issues of corruption in the Lands Department, illiteracy among landowners, poor publicity given to ILGs’ functions, and the dysfunctional ILG legal framework.

  18. Epidermal cell proliferation in guinea pigs with experimental dermatophytosis

    International Nuclear Information System (INIS)

    To elucidate the mechanisms underlying the self-healing process of experimental dermatophytosis produced in guinea pigs by an occlusive method with Trichophyton mentagrophytes, epidermal proliferative activity was evaluated by the in vivo tritiated thymidine-labeling technique performed at various intervals after the first and second infections. Determination of labeling indices disclosed that an increased epidermal proliferation correlated well with the severity of inflammatory changes, i.e., a peak activity was noted after 10 days in primary infection and at 2 days in reinfection, respectively, and was followed by subsequent spontaneous lesion clearance after 10 days. Application of a heat-killed spore suspension produced inflammatory changes with enhanced epidermopoiesis, similar to those induced by reinoculation of living spores, only in immune animals. The present results indicate that the dermatitic changes occurring in experimental dermatophytosis increase epidermopoiesis which facilitates elimination of the fungus from the stratum corneum and that host immune activity, particularly contact sensitivity to fungal antigen, exerts a crucial role to induce these changes

  19. Sources and management of hazardous waste in Papua New Guinea

    Energy Technology Data Exchange (ETDEWEB)

    Singh, K. [Univ. of Papua New Guinea (Papua New Guinea)

    1996-12-31

    Papua New Guinea (PNG) has considerable mineral wealth, especially in gold and copper. Large-scale mining takes place, and these activities are the source of most of PNG`s hazardous waste. Most people live in small farming communities throughout the region. Those living adjacent to mining areas have experienced some negative impacts from river ecosystem damage and erosion of their lands. Industry is centered mainly in urban areas and Generates waste composed of various products. Agricultural products, pesticide residues, and chemicals used for preserving timber and other forestry products also produce hazardous waste. Most municipal waste comes from domestic and commercial premises; it consists mainly of combustibles, noncombustibles, and other wastes. Hospitals generate pathogenic organisms, radioactive materials, and chemical and pharmaceutical laboratory waste. Little is known about the actual treatment of waste before disposal in PNG. Traditional low-cost waste disposal methods are usually practiced, such as use of landfills; storage in surface impoundments; and disposal in public sewers, rivers, and the sea. Indiscriminate burning of domestic waste in backyards is also commonly practiced in urban and rural areas. 10 refs., 4 tabs.

  20. Ouabain uptake by endocytosis in isolated guinea pig atria

    International Nuclear Information System (INIS)

    Mammalian cells specifically internalize some molecular species through receptor-mediated endocytosis (RME). The authors have used four different experimental protocols to investigate whether ouabain enters cardiac cells of guinea pig atrium through this pathway. First, by electron microscope morphometry the authors found that ouabain increased endocytic vesicles in atrial cells. Second, by scintillation counting they found that [3H]ouabain uptake by the tissue is decreased by three treatments that decrease RME, i.e., NH4Cl, trifluoperazine, and 16 mM [K+]0. Third, by radioautography at the electron microscope level, they checked that in preceding experiments [3H]ouabain was washed out of plasma membrane after 60-min rinse and interiorized into the cardiac cells. Fourth, isometric tension recordings showed that the positive inotropic effect of ouabain was diminished in the presence of inhibitors, whereas that of a hydrophobic analogue, ouabagenin, was not affected. These results suggest that ouabain enters cardiac cells through RME and also that an intracellular site may, at least in part, be responsible for its inotropic effect

  1. Gene Targeting to the Uteroplacental Circulation of Pregnant Guinea Pigs.

    Science.gov (United States)

    Mehta, Vedanta; Ofir, Keren; Swanson, Anna; Kloczko, Ewa; Boyd, Michael; Barker, Hannah; Avdic-Belltheus, Adnan; Martin, John; Zachary, Ian; Peebles, Donald; David, Anna L

    2016-08-01

    Our study aimed to target adenoviral gene therapy to the uteroplacental circulation of pregnant guinea pigs in order to develop a novel therapy for fetal growth restriction. Four methods of delivery of an adenovirus encoding β-galactosidase (Ad.LacZ) were evaluated: intravascular injection using phosphate-buffered saline (PBS) into (1) uterine artery (UtA) or (2) internal iliac artery or external administration in (3) PBS or (4) pluronic F-127 gel (Sigma Aldrich). Postmortem examination was performed 4 to 7 days after gene transfer. Tissue transduction was assessed by X-gal histochemistry and enzyme-linked immunosorbent assay. External vascular application of the adenovirus vector in combination with pluronic gel had 91.7% success rate in terms of administration (85% maternal survival) and gave the best results for maternal/fetal survival and local transduction efficiency without any spread to maternal or fetal tissues. This study suggests an optimal method of gene delivery to the UtAs of a small rodent for preclinical studies. PMID:26865541

  2. Late effects of radiation on the lumbar spinal cord of guinea pigs: Re-treatment tolerance

    International Nuclear Information System (INIS)

    Using a guinea pig model of lumbar myelopathy, various factors affecting the tolerance of spinal cord to irradiation were assessed: (a) extent of initial injury; (b) time interval between priming and test doses; and (c) animal age at the time of initial radiation treatment. A 3 cm section of lumbar spinal cord of guinea pigs was irradiated with fractionated doses of 4.5 Gy gamma rays given as 9 fractions per week. Guinea pigs were primed with 9 x 4.5 Gy in 7 days which is 60% of the ED50 for a continuous course of treatment. After 28 or 40 weeks, animal were retreated with 6-14 fractions of 4.5 Gy. Animals were observed for 2 years following the priming dose and both the incidence and latency of myelopathy recorded. Young adult guinea pigs (8 wk old) showed both a decreased radiation tolerance and latency compared to old individuals (40 wk old). At 28 or 40 wk after 9 x 4.5 Gy, only about 8% of the initial injury was remembered in young adult guinea pigs. The amount of residual injury was dependent on the initial damage as a proportion of the tolerance dose. The spinal cord shows a greater capacity for long-term recovery than generally appreciated and re-treatment doses clinically prescribed may be lower than necessary. 8 refs., 3 figs., 2 tabs

  3. Response to the Ebola epidemics in Guinea: Public Health Organisational issues and possible solutions

    Directory of Open Access Journals (Sweden)

    Thierno Baldé

    2015-09-01

    Full Text Available Because of its magnitude and changing dynamics, the Ebola epidemics currently affecting some West African countries constitutes one of the most serious public health problems in recent decades. Conceptualised as a case study with two levels of analysis, this article aims at analysing the response to the Ebola epidemics in Guinea in order to ultimately highlight the public health organisational issues related to this response and to propose some possible solutions to improve the efficiency of this response. This article is based on documentary analysis, observation and a three month participating immersion conducted in Guinea from June 2014 to August 2014. Using certain elements of Parsons’ social action theory, this study has shown the existence of 4 systems of social intervention in the organisation and management of the response to the Ebola epidemics in Guinea. They are the WHO, MSF, the Red Cross and the Ministry of Health. Each of these systems of social intervention has specific characteristics and specificities and interacts actively at several levels of the healthsystem of Guinea. Having completed the analysis of the interventions undertaken by these 4 systems of social action, and using the conceptual basis of the complexity theory, we propose some avenues for reflection and action for improving the quality of the response to the Ebola epidemics in Guinea, in order to finally restrain and stop its propagation in other African countries and other continents.

  4. Congenital malformations caused by Stryphnodendron fissuratum (Leg. Mimosoideae) in guinea pigs (Cavia porcellus).

    Science.gov (United States)

    Macedo, Josenaldo S; Rocha, Brena P; Colodel, Edson M; Freitas, Sílvio H; Dória, Renata G S; Riet-Correa, Franklin; Evêncio-Neto, Joaquim; Mendonça, Fábio S

    2015-11-01

    The aim of this study was to evaluate the toxicity of Stryphnodendron fissuratum pods in guinea pigs (Cavia porcellus) and test the hypothesis that this plant has teratogenic effects. Thus, sixteen guinea pigs were randomly divided into four groups of four animals each. Groups 10, 20 and 40 consisted of guinea pigs that received commercial food that contained crushed pods of S. fissuratum at concentrations of 10, 20 and 40 g/kg, respectively, during the period of organogenesis. Control group consisted of guinea pigs under the same management conditions that did not receive crushed pods of S. fissuratum in their food. In all experimental groups, the main clinical signs of poisoning consisted of anorexia, prostration, absence of vocalizations, alopecia, diarrhea, and abortions within the adult guinea pigs. Those that did not abort gave birth to weak, malnourished pups, some of which had fetal malformations. The main teratogenic changes consisted of eventration, arthrogryposis, amelia of the forelimbs, anophthalmia, microphthalmia, anotia and agnathia. The reductions in the number of offspring and the malformations observed in the experimental groups suggest that S. fissuratum affects fetal development and is teratogenic. PMID:26363291

  5. Increasing Guinea Fowl Eggs Availability and Hatchability in the Dry Season

    Directory of Open Access Journals (Sweden)

    S.P. Konlan

    2011-12-01

    Full Text Available The study was designed to identify the possibility of making guinea fowls (Numida meleagris to lay fertile eggs throughout the year and was investigated for nine months. Fifty guinea fowls (growers consisting of ten males and forty females were purchased and raised to laying stage. At the laying stage, they were fed with commercial layer diet, confined in the day time and opened at 3:00 p.m. to go out and forage until 6:00 p.m. when they were driven back into the pen. Their supplementary feed intake and egg laying performance were monitored during the period. The eggs were artificially incubated to determine hatching rate. The results showed that the fowls’ mean supplementary feed intake was 84.5g/fowl/day and laid a total of 3,920 eggs in nine months investigation period by an average of 39 guinea hens. The hatching rate of the eggs was mostly found to be in the range of 66% to 69% but fell sharply to 18% in December at the peak of the harmattan season. It was concluded that good feeding and provision of water ad lib to the guinea fowls were effective means of making them lay eggs even in the dry season. The North – East dry winds (harmattan which occur annually from November to February, was suspected to have negative influence on guinea fowl egg production and hatchability.

  6. 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 to the......-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...

  7. A detailed discussion of effects of geomagnetic storms on the dynamics and electrodynamics of the equatorial upper atmosphere

    International Nuclear Information System (INIS)

    Complete text of publication follows. There is a long chain of processes between the arrival of strong bursts of solar wind at the earth's magnetosphere and the onset of their effects in the ionosphere. We review most of these steps in a didactic and critical way using as many illustrations as possible. The discussion considers the quiet time equatorial dynamo, the prompt penetration electric field, the disturbed dynamo, and how each of these affects the onset of equatorial plasma bubbles. The quiet time and disturbed seed electric fields of the equatorial electrojet are also discussed.

  8. 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

  9. 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

  10. Study of the magmatism related to the rifting of the central and southern Atlantic: 40Ar/39Ar geochronology and geochemistry of Jurassic intrusives of Guinea and French Guyana/Surinam, and Cretaceous intrusives of Brazil

    International Nuclear Information System (INIS)

    The initial stage of continental rifting in the Central and South Atlantic has been accompanied by tholeiitic magmatism, which is mainly represented by sills, dykes, layered intrusions and lava flows. During the rifting progression, the syn-rift stage in the South Atlantic has been accompanied by abundant alkaline magmatism. A geochronological and geochemical study has been performed on these formations with the aim to contribute to the understanding of the early continental rifting processes and their evolution. 40Ar/39Ar analyses have been done on tholeiitic intrusives of Guinea and French Guyana/Surinam, tholeiitic dykes, associated with the Parana volcanism (Brazil), and alkaline dykes in the region of Rio de Janeiro (Brazil). The geochemical and isotopic study has been focused on the tholeiitic intrusions from Guinea and French Guyana/Surinam. These three arms may represent the three branches of a triple junction which was active between 134 to 129 Ma, and which was at the origin of at least the northern Parana traps. Even if the principal magmatic activity can be related to the thermal anomaly due to the Tristan da Cunha hotspot, which favours an active rifting, the tectonic system of the triple junction is not compatible in time and space with this hotspot and therefore with this geodynamic model. It is possible that the Parana traps (133-130 Ma) are only partly contemporaneous and therefore, they might be not related to the same mode of geodynamic initiation. Biotites from the alkaline magmatics of the dyke swarm (NE-SW) near Rio de Janeiro display plateau ages between 82 and 70 Ma; this intense alkaline magmatism was related to vertical movements characterising the syn-rift stage not only in SE-Brazil but also in equatorial Africa. (author)

  11. Gender Differences in the Anatomy of the Perineal Glands in Guinea Pigs and the Effect of Castration

    DEFF Research Database (Denmark)

    Iburg, T. M.; Arnbjerg, J.; Ruelokke, M. L.

    2013-01-01

    Perineal glands in guinea pigs are part of the sebaceous glandular complex. Their secretions are used for scent marking. This is important for social status and can be seen in both sexes and castrated males. Discrepancy exits about the existence of these glands in female guinea pigs and knowledge...

  12. A comparative analysis of the intestinal metagenomes present in guinea pigs (Cavia porcellus and humans (Homo sapiens

    Directory of Open Access Journals (Sweden)

    Hildebrand Falk

    2012-09-01

    Full Text Available Abstract 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, but at genus level, the majority of identified genera (320 of 376 were differently abundant in the two hosts. For example, the guinea pig contained considerably more of the mucin-degrading Akkermansia, as well as of the methanogenic archaea Methanobrevibacter than found in humans. Most microbiome functional categories were less abundant in guinea pigs than in humans. Exceptions included functional categories possibly reflecting dehydration/rehydration stress in the guinea pig intestine. Finally, we showed that microbiological databases have serious anthropocentric biases, which impacts model organism research. Conclusions The results lay the foundation for future gastrointestinal research applying guinea pigs as models for humans.

  13. Effects of long term feeding of raw soya bean flour on virus- induced pancreatic carcinogenesis in guinea fowl

    NARCIS (Netherlands)

    Kirev, T.; Woutersen, R.A.; Kiril, A.

    1999-01-01

    The effects of a diet enriched with 25% raw soya bean flour (RSF) on the pancreas and on the avian retrovirus Pts 56-induced pancreatic carcinogenesis in guinea fowl were studied. It has been shown that prolonged RSF feeding of new-hatched virus-infected and uninfected guinea fowl-poults induced enl

  14. 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; Ravn, Henrik; Andersen, Andreas; Balde, Ibraima Djogo; Leo-Hansen, Christian; Rodrigues, Amabelia; Aaby, Peter; Benn, Christine Stabell

    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....

  15. Human Recombinant PLD2 Can Repress p65 Activity of Guinea Pigs of Chronic Asthma in vivo

    Institute of Scientific and Technical Information of China (English)

    Ling Zhu; Weibin Zou; Chuanxing Yu; Junjin Lin; Xiaoli He

    2006-01-01

    This article is to investigate the effect of human recombinant phospholipase D2 (rhPLD2) in vivo on the expression of nuclear transcription factor p65 in chronic asthma of guinea pigs. After treating the guinea pigs with chronic asthma by rhPLD2, the crude nuclear extraction was assayed with TransAM Transcription Factor Assay Kit for the activity of pulmo tissue nuclear transcription factor p65. Compared with the healthy guinea pigs, the activity of nuclear transcription factor p65 in guinea pigs of chronic asthma is much higher than that of control groups. Our results showed that rhPLD2 markedly depressed the activity of p65 when the guinea pigs were attacked by chronic asthma. Cellular & Molecular Immunology. 2006;3(4):307-310.

  16. Effect of Cerium on Cardiac Muscle of Rat and Guinea Pig

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of Ce3+ on cardiac muscle of rat and guinea pig was studied. In vitro, 0.05 mmol.L-1 solution of Ce3+ inhibited the contraction of guinea pig atria. The change of action potential duration(APD) of guinea pig papillary muscle exposed to 0.4 mmol·L-1 Ce3+ was significant, and those exposed to 0.1 and 0.2 mmol·L-1 Ce3+ were not significant. In vivo, compared with the control group, the APD for rat cardiac muscle after long-term feed on Ce3+ was significantly delayed in high dose, and that was not significantly delayed in low dose. The results suggest that Ce3+ with long-term high dose intake might affect the influx of Ca2+, Na+ and outflow of K+ for rat cardiac muscle.

  17. Disodium cromoglycate prevents ileum hyperreactivity to histamine in Toxocara canis-infected guinea pigs.

    Science.gov (United States)

    Sá-Nunes, A; Corrado, A P; Baruffi, M D; Faccioli, L H

    2003-11-01

    The aim of this study was to investigate whether Toxocara canis infection in guinea pigs provokes changes in ileum responsiveness to histamine. Ileum segments from control and T. canis-infected groups were placed at isometric conditions and submitted to various doses of histamine. No changes were observed between controls and T. canis-infected groups at days 3, 6 and 12 after infection. However, at days 18 and 24 after infection, there was a significant increase in ileum responsiveness to histamine in T. canis-infected group. Pre-incubation of ileum segments with 1mgml(-1) disodium cromoglycate (DSCG) prevented the increased responsiveness to histamine in T. canis-infected guinea pigs and did not affect ileum contractility in non-infected animals. These results indicate that T. canis-infected guinea pigs develop increased intestinal responsiveness to histamine and that DSCG prevents alterations in smooth-muscle contractility. PMID:12967589

  18. Improved laboratory capacity is required to respond better to future cholera outbreaks in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Paul Horwood

    2012-05-01

    Full Text Available Cholera was first detected in Papua New Guinea in July 2009, caused by Vibrio cholerae O1 El Tor serotype Ogawa. By late 2011, 15 500 cases had been reported throughout lowland Papua New Guinea with a case fatality rate of 3.2%. The epidemic has since slowed, with only sporadic cases reported in Western Province and the Autonomous Region of Bougainville (ARB. Accurate and timely diagnosis is a critical element of the public health response to cholera, yet in low-income countries where the burden of cholera is the greatest, diagnostic services are often limited. Here we report on the diagnostic challenges and the logistical factors that impacted on diagnosis during the first reported outbreak of cholera in Papua New Guinea.

  19. Phosphodiesterase 5 and effects of sildenafil on cerebral arteries of man and guinea pig

    DEFF Research Database (Denmark)

    Kruuse, Christina; Khurana, Tejvir S; Rybalkin, Sergei D; Birk, Steffen; Engel, Ulla; Edvinsson, Lars; Olesen, Jes

    less effective on the cGMP hydrolysis in cerebral arteries, and that sildenafil may not be an effective dilator of cerebral arteries under baseline conditions. We evaluated the presence of PDE5 mRNA and protein in human arteries. Furthermore, the effects of two selective PDE5 inhibitors, sildenafil and...... UK-114,542, and a PDE1 inhibitor UK-90,234 on cGMP hydrolysis were investigated in human and guinea pig cerebral arteries. The vasoactive responses of the compounds were evaluated in guinea pig basilar arteries in vitro, with concomitant measurements of cAMP and cGMP. PDE5 was found in human middle...... cerebral arteries. Sildenafil and UK-114,542 inhibited cGMP hydrolysis concentration-dependently in both species. In guinea pig arteries, sildenafil induced an endothelium-dependent vasodilatation only at concentrations above 10 nM, which was augmented by sodium nitroprusside and attenuated by reduction of...

  20. Inhibition of gastric secretion in guinea pig by relatively low dose ionizing radiation

    International Nuclear Information System (INIS)

    We evaluated the effect of a single dose of ionizing radiation on gastric secretion in awake guinea pigs equipped with a permanent gastric cannula. Changes in gastric secretion were measured using a dye dilution technique. Infusion of histamine increased acid and fluid output and there was a positive correlation (r = 0.93) between the two. Total body irradiation with 400 cGy, like cimetidine, suppressed acid and fluid secretion under basal conditions and during histamine stimulation by 50-90%. Recovery from the radiation damage was only partial after one week. Irradiation inhibited the rise in gastric juice volume during histamine stimulation and also reduced the normal gain in body weight of the guinea pig. These results demonstrate that ionizing radiations have an immediate and long lasting effects on the gastric mucosal function of the guinea pig

  1. GABAB Receptor Antagonist CGP46381 Inhibits Form-Deprivation Myopia Development in Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Zhen-Ying Cheng

    2015-01-01

    Full Text Available The aim was to investigate the effects of the GABAB receptor antagonist, CGP46381, on form-deprivation myopia (FDM in guinea pigs. Twenty-four guinea pigs had monocular visual deprivation induced using a diffuser for 11 days (day 14 to 25. The deprived eyes were treated with daily subconjunctival injections (100 μl of either 2% CGP46381, 0.2% CGP46381, or saline or received no injection. The fellow eyes were left untreated. Another six animals received no treatment. At the start and end of the treatment period, ocular refractions were measured using retinoscopy and vitreous chamber depth (VCD and axial length (AL using A-scan ultrasound. All of the deprived eyes developed relative myopia (treated versus untreated eyes, P0.05. Subconjunctival injections of CGP46381 inhibit FDM development in guinea pigs in a dose-dependent manner.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Spatial variability in macroinvertebrate assemblages along and among neighbouring equatorial glacier-fed streams

    DEFF Research Database (Denmark)

    Kuhn, J.; Andino, P.; Calvez, R.;

    2011-01-01

    Andes of Ecuador. Our main goals were (i) to determine overall longitudinal patterns in density, taxon richness and the composition of macroinvertebrate assemblages and driving factors in equatorial glacial streams and (ii) to examine variability among replicate streams in faunal metrics and assemblages...... sites, following a supposed decrease in environmental harshness along the streams. Relationships between faunal metrics and the four environmental variables mean temperature, the stability index, chlorophyll a and coarse particulate organic matter also varied among the three streams. Generalised linear...... and temperature and stability as main driving factors were met by our three replicate equatorial glacial streams. Qualitative departures from the model were mainly because of zoogeographical differences. We demonstrated that variability in assemblages between comparable sites in closely situated...

  7. 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.

  8. Solar flux variation of the electron temperature morning overshoot in the equatorial F region

    DEFF Research Database (Denmark)

    Stolle, Claudia; Liu, H.; Truhlik, V.;

    2011-01-01

    similar magnitude are predicted by the FLIP model. The model calculations confirm that the electron cooling due to enhanced electron-ion collisions increases faster than the heating of thermal electrons through collision with photoelectrons for increasing solar EUV. Both data and model showed that......Using 8 years of CHAMP satellite observations of the equatorial electron temperature, T-e, we investigate its behavior during the morning overshoot and at ionospheric altitudes below 450 km including its variation with solar activity. The morning T-e has a maximum at the dip equator and decreases...... gradually with increasing latitude, which is due to the increasing importance of heat conduction as the dip angle becomes larger. The amplitude of the equatorial morning overshoot T-e decreases with increasing solar flux by about -10 degrees K/solar flux unit depending on season and longitude. Trends of...

  9. Three-dimensional simulation of equatorial spread-F with meridional wind effects

    Directory of Open Access Journals (Sweden)

    J. Krall

    2009-05-01

    Full Text Available The NRL SAMI3 three-dimensional simulation code is used to examine the effect of meridional winds on the growth and suppression of equatorial spread F (ESF. The simulation geometry conforms to a dipole field geometry with field-line apex heights from 200 to 1600 km at the equator, but extends over only 4 degrees in longitude. The full SAMI3 ionosphere equations are included, providing ion dynamics both along and across the field. The potential is solved in two dimensions in the equatorial plane under a field-line equipotential approximation. By selectively including terms in the potential equation, the reduced growth predicted by Maruyama (1988 and the stabilization predicted by Zalesak and Huba (1991 are separately realized. We find that ESF is stabilized by a sufficiently large constant meridional wind (60 m/s in our example.

  10. 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

  11. 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.

  12. Conjugated linoleic acid mitigates testosterone-related changes in body composition in male guinea pigs.

    Science.gov (United States)

    Yang, Susan Q; DeGuire, Jason R; Lavery, Paula; Mak, Ivy L; Weiler, Hope A; Santosa, Sylvia

    2016-05-01

    We hypothesize that conjugated linoleic acid (CLA) may be effective in preventing the changes in total and regional body composition and increases in interleukin (IL) 6 that occur as a result of hypogonadism. Male guinea pigs (n = 40, 70- to 72-week retired breeders) were block randomized by weight into 4 groups: (1) sham surgery (SHAM)/control (CTRL) diet, (2) SHAM/conjugated linoleic acid (CLA) diet (1%), (3) orchidectomy (ORX)/CTRL diet, and (4) ORX/CLA diet. Dual-energy x-ray absorptiometry scans were performed at baseline and week 16 to assess body composition. Serum IL-6 was analyzed using an enzyme-linked immune sorbent assay. Fatty acids (FAs) from visceral and subcutaneous adipose tissue were analyzed using gas chromatography. In ORX/CTRL guinea pigs, percent total body fat increased by 6.1%, and percent lean mass decreased by 6.7% over the 16-week treatment period, whereas no changes were observed for either parameter in ORX/CLA guinea pigs. Guinea pigs fed the CLA diet gained less percent total, upper, and lower body fat than those fed the CTRL diet regardless of surgical treatment. Regional adipose tissue FA composition was reflective of dietary FAs. Serum IL-6 concentrations were not different among groups. In this study, we observed that, in male guinea pigs, hypogonadism resulted in increased fat mass and decreased lean mass. In addition, CLA was effective in reducing gains in body fat and maintaining lean mass in both hypogonadal and intact guinea pigs. PMID:27101759

  13. A step forward for understanding the morbidity burden in Guinea: a national descriptive study

    Directory of Open Access Journals (Sweden)

    Hu Guoqing

    2011-06-01

    Full Text Available Abstract Background Little evidence on the burden of disease has been reported about Guinea. This study was conducted to demonstrate the morbidity burden in Guinea and provide basic evidence for setting health priorities. Methods A retrospective descriptive study was designed to present the morbidity burden of Guinea. Morbidity data were extracted from the National Health Statistics Report of Guinea of 2008. The data are collected based on a pyramid of facilities which includes two national hospitals (teaching hospitals, seven regional hospitals, 26 prefectural hospitals, 8 communal medical centers, 390 health centers, and 628 health posts. Morbidity rates were calculated to measure the burden of non-fatal diseases. The contributions of the 10 leading diseases were presented by sex and age group. Results In 2008, a total of 3,936,599 cases occurred. The morbidity rate for males was higher than for females, 461 versus 332 per 1,000 population. Malaria, respiratory infections, diarrheal diseases, helminthiases, and malnutrition ranked in the first 5 places and accounted for 74% of the total burden, respectively having a rate of 148, 64, 33, 32, and 14 per 1,000 population. The elderly aged 65+ had the highest morbidity rate (611 per 1,000 population followed by working-age population (458 per 1,000 population and children (396 per 1,000 population while the working-age population aged 25-64 contributed the largest part (39% to total cases. The sex- and age-specific spectrum of morbidity burden showed a similar profile except for small variations. Conclusion Guinea has its unique morbidity burden. The ten leading causes of morbidity burden, especially for malaria, respiratory infections, diarrheal diseases, helminthiases, and malnutrition, need to be prioritized in Guinea.

  14. Adenosine transport systems on dissociated brain cells from mouse, guinea-pig, and rat

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, M.E.; Geiger, J.D. (Univ. of Manitoba, Winnipeg (Canada))

    1990-09-01

    The kinetics and sodium dependence of adenosine transport were determined using an inhibitor-stop method on dissociated cell body preparations obtained from mouse, guinea-pig and rat brain. Transport affinity (KT) values for the high affinity adenosine transport systems KT(H) were significantly different between these three species; mean +/- SEM values were 0.34 +/- 0.1 in mouse, 0.9 +/- 0.2 in rat, and 1.5 +/- 0.5 microM in guinea-pig. The KT values for the low affinity transport system KT(L) were not different between the three species. Brain cells from rat displayed a significantly greater maximal capacity to accumulate (3H)adenosine (Vmax) than did mouse or guinea-pig for the high affinity system, or than did mouse for the low affinity system. When sodium chloride was replaced in the transport medium with choline chloride, the KT(H) values for guinea-pig and rat were both increased by approximately 100%; only in rat did the change reach statistical significance. The sodium-dependence of adenosine transport in mouse brain was clearly absent. The differences between KT(H) values in mouse and those in guinea-pig or rat were accentuated in the absence of sodium. The differences in kinetic values, ionic requirements, and pharmacological characteristics between adenosine transporters in CNS tissues of mouse, guinea-pig and rat may help account for some of the variability noted among species in terms of their physiological responses to adenosine.

  15. Azimuthal directions of equatorial noise propagation determined using 10 years of data from the Cluster spacecraft

    Czech Academy of Sciences Publication Activity Database

    Němec, F.; Santolík, Ondřej; Pickett, J. S.; Hrbáčková, Zuzana; Cornilleau-Wehrlin, N.

    2013-01-01

    Roč. 118, č. 11 (2013), 7160–7169. ISSN 2169-9380 R&D Projects: GA ČR GAP205/10/2279 Institutional support: RVO:68378289 Keywords : equatorial noise * fast magnetosonic wave s * fast magnetosonic wave s Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/2013JA019373/abstract

  16. Large-scale shifts in phytoplankton groups in the Equatorial Pacific during ENSO cycles

    Directory of Open Access Journals (Sweden)

    I. Masotti

    2011-03-01

    Full Text Available The El Niño Southern Oscillation (ENSO drives important changes in the marine productivity of the Equatorial Pacific, in particular during major El Niño/La Niña transitions. Changes in environmental conditions associated with these climatic events also likely impact phytoplankton composition. In this work, the distribution of four major phytoplankton groups (nanoeucaryotes, Prochlorococcus, Synechococcus, and diatoms was examined between 1996 and 2007 by applying the PHYSAT algorithm to the ocean color data archive from the Ocean Color and Temperature Sensor (OCTS and Sea-viewing Wide Field-of-view Sensor (SeaWiFS. Coincident with the decrease in chlorophyll concentrations, a large-scale shift in the phytoplankton composition of the Equatorial Pacific, that was characterized by a decrease in Synechococcus and an increase in nanoeucaryote dominance, was observed during the early stages of both the strong El Niño of 1997 and the moderate El Niño of 2006. A significant increase in diatoms dominance was observed in the Equatorial Pacific during the 1998 La Niña and was associated with elevated marine productivity. An analysis of the environmental variables using a coupled physical-biogeochemical model (NEMO-PISCES suggests that the Synechococcus dominance decrease during the two El Niño events was associated with an abrupt decline in nutrient availability (−0.9 to −2.5 μM NO3 month−1. Alternatively, increased nutrient availability (3 μM NO3 month−1 during the 1998 La Niña resulted in Equatorial Pacific dominance diatom increase. Despite these phytoplankton community shifts, the mean composition is restored after a few months, which suggests resilience in community structure.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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

  7. 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 ...

  8. 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...

  9. Tether radiation in Juno-type and circular-equatorial Jovian orbits

    OpenAIRE

    Sánchez-Torres, Antonio; Sanmartín Losada, Juan Ramón

    2011-01-01

    Wave radiation by a conductor carrying a steady current in both a polar, highly eccentric, low perijove orbit, as in NASA's planned Juno mission, and an equatorial low Jovian orbit (LJO) mission below the intense radiation belts, is considered. Both missions will need electric power generation for scientific instruments and communication systems. Tethers generate power more efficiently than solar panels or radioisotope power systems (RPS). The radiation impedance is required to determin...

  10. Seasonal Variation of Diurnal Cycle of Rainfall in the Eastern Equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Pednekar, S.; Katsumata, M.; Antony, M.K.; Kuroda, Y.; Unnikrishnan, A.S.

    and their range and accuracy. The data from the optical rain gauge (ORG) showed good correlation to that of the simultaneously observed capacitance rain gauge (CRG), though the ORG measured rain is larger than that of CRG?s with a factor less than 2... summer, where the semidiurnal and six hourly harmonics are significant. Index Terms ? Diurnal Variation, Rainfall, TRITON, Buoy, Eastern Equatorial Indian Ocean. 1. Introduction Traditionally, the precipitation over the ocean is measured...

  11. 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...

  12. 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...

  13. 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...

  14. Statistical analysis of equatorial noise emissions as a function of magnetic local time

    Czech Academy of Sciences Publication Activity Database

    Hrbáčková, Zuzana; Němec, F.; Santolík, Ondřej

    Praha: Matfyzpress, 2011, s. 85-90. ISBN 978-80-7378-185-9. [Week of doctoral students 2011. Prague (CZ), 31.05.2011-03.06.2011] Institutional research plan: CEZ:AV0Z30420517 Keywords : Cluster spacecraft * Earth's magnetosphere * equatorial noise emission Subject RIV: BL - Plasma and Gas Discharge Physics http://www.mff.cuni.cz/veda/konference/wds/proc/proc-contents.php?year=2011#ppm

  15. Systematic Analysis of Equatorial Noise Using Data of the Cluster Mission

    Czech Academy of Sciences Publication Activity Database

    Hrbáčková, Zuzana

    Prague: MATFYZPRESS, 2010 - (Šafránková, J.; Pavlů, J.), s. 183-188 ISBN 978-80-7378-140-8. [Week of Doctoral Students 2010. Annual Student Conference /19./. Prague (CZ), 01.06.2010-04.06.2010] R&D Projects: GA ČR GAP205/10/2279 Institutional research plan: CEZ:AV0Z30420517 Keywords : Analysis * Equatorial Noise * Cluster Mission Subject RIV: BL - Plasma and Gas Discharge Physics

  16. Occurrence Rate of Equatorial Noise Emissions as a Function of the McIlwain's Parameter

    Czech Academy of Sciences Publication Activity Database

    Hrbáčková, Zuzana; Santolík, Ondřej

    Prague: MATFYZPRESS, 2012 - (Šafránková, J.; Pavlů, J.), s. 205-209 ISBN 978-80-7378-225-2. [Week of doctoral students 2012. Prague (CZ), 29.05.2012-01.06.2012] Institutional support: RVO:68378289 Keywords : Cluster spacecraft * Earth's magnetosphere * equatorial noise emission * magnetic local time Subject RIV: BL - Plasma and Gas Discharge Physics http://www.mff.cuni.cz/veda/konference/wds/proc/wds12.php#ppm

  17. 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.

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

    OpenAIRE

    R. L. Sriver; Huber, M.; L. Chafik

    2013-01-01

    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...

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

    OpenAIRE

    R. L. Sriver; Huber, M.; L. Chafik

    2012-01-01

    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...

  20. 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.