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1.
Callus-, root-, shoot-, and rooted shoot cultures of Geigeria aspera were established on Murashige and Skoog's nutrient medium. Organogenesis of roots and shoots was induced with treatments containing BA or KN in combination with NAA, IAA, IBA or 2, 4-D. Rooted plantlets were successfully transplanted into soil. 相似文献
2.
S. Ortiz 《Nordic Journal of Botany》2003,23(3):315-332
We present a synopsis of the genus Geigeria (Inuleae, Asteraceae). Particular attention is paid to the taxonomic characterization and phylogenetic relationships of the genus, to possible supraspecific groupings, and to the delimitation of taxa, especially at the infraspecific level. Until recently 25 species, 20 subspecies, and 7 varieties have been recognized. In this study we recognize only 20 species, 12 subspecies, and 7 varieties. We describe a new subspecies and variety, and propose 5 new nomenclatural combinations. 相似文献
3.
Antje Burke 《植被学杂志》1995,6(4):473-478
Abstract. Seed heteromorphism in annual Geigeria alata in the Namib Desert was investigated in relation to environmental conditions. Geigeria alata shows heteromorphism in seed dispersal distance depending on the position of the seeds on the parent plant. Seeds produced in capitula on branches (aerial) travel long distances, while seeds produced at the base of the plant remain in the vicinity of the parent plant. The ratio of aerial to basal seed production was investigated under different environmental conditions following an aridity gradient. Although there were significant differences in seed and capitula production between seasons and between different positions on the plant, no overall trend was found with increasing aridity. 相似文献
4.
The species from Angola Pleiotaxis huillensis (Mutisieae, Asteraceae) is subdivided into three subspecies and one variety. Specifically, P. huillensis subsp axillaris and P. huillensis subsp. huillensis var. macrocephala are described as new taxa, and a new nomenclatural combination is proposed ( P. huillensis subsp. argentea ). 相似文献
5.
S. ORTIZ F.L.S. J. A. R. PAIVA F.L.S. 《Botanical journal of the Linnean Society. Linnean Society of London》1995,117(1):39-46
Two new species of the genus Anisopappus Hook. & Arn. (Asteraceae) are described A. athanasioides Paiva & Ortiz, from Angola, and A. pseudopinnatifidus Ortiz & Paiva, from Namibia. The morphological variability of the A. chinensia-A. africanus complex is studied and two new combinations are proposed: A. chinensis subsp. africanus (Hook. fil.) Ortiz & Paiva and A. chinensis subsp. lobatus (Wild) Ortiz & Paiva. 相似文献
6.
S. ORTIZ F.L.S. J. A. R. PAIVA F.L.S. 《Botanical journal of the Linnean Society. Linnean Society of London》1995,117(2):39-46
Two new species of the genus Anisopappus Hook. & Arn. (Asteraceae) are described: A. athanasioides Paiva & Ortiz, from Angola, and A. pseudopinnaididus Ortiz & Paiva, from Namibia. The morphological variability of the A. chinensis-A. africanus complex is studied and two new combinations are proposed: A. chinensis subsp. africanus (Hook, fil.) Ortiz & Paiva and A. chinensis subsp. lobatus (Wild) Ortiz & Paiva. 相似文献
7.
SANTIAGO ORTIZ FLS JORGE A. R. PAIVA FLS 《Botanical journal of the Linnean Society. Linnean Society of London》1999,131(2):167-176
As part of taxonomic studies of the family Polygonacrae For the Flora Zambesiaca project, two new species from southrrn tropical Africa are described: Persicaria nogueirae S. Ortiz & Paiva, from Zambia and Angola, and Oxygonum annuum S. Ortiz & Paiva, from Zambia. In addition, two new combinations are proposed: Polygonum glomertum Dammer is transferred to the genus Persicaria as Persicaria glomerata (Dammrr) S. Ortiz & Paiva, and Persicaria attemtata (R. Br.) Soják subsp. africana K.L. Wilson is renamed Persicaria madagascariensis (Meisn.) S. Ortiz & Paiva. 相似文献
8.
Antje Günster 《植被学杂志》1993,4(5):585-590
Abstract. Four coexisting serotinous desert plants in the central Namib were investigated with respect to microhabitat preferences. The annual Blepharis grossa preferred the microhabitat on the plains, while the perennial Petalidium setosum dominated in channels. The remaining two species, the common Geigeria alata and the rare Geigeria ornativa, were evenly distributed in all microhabitats. Interspecific competition, seed dispersal mode and ecophysiological niches might be responsible for this pattern. 相似文献
9.
Phradonoma blabolili
sp. n. from Angola is described and illustrated. Key to the Afrotropical “Phradonoma nobile species group” to which the newly described species belongs, as well as key to genera of dermestid beetles occurring in Angola is given. List of all species of Dermestidae known to occur in Angola hitherto is provided. 相似文献
10.
Zoraima Neto Pedro A. Martinez Sarah C. Hill Domingos Jandondo Julien Thz Marinela Mirandela Renato Santana Aguiar Joilson Xavier Cruz dos Santos Sebastio Ana Luísa Micolo Cndido Filipa Vaz Gisel Reyes Castro Joana Paula Paixo Nicholas J. Loman Philippe Lemey Oliver G. Pybus Jocelyne Vasconcelos Nuno Rodrigues Faria Joana de Morais 《PLoS neglected tropical diseases》2022,16(5)
BackgroundThe transmission patterns and genetic diversity of dengue virus (DENV) circulating in Africa remain poorly understood. Circulation of the DENV serotype 1 (DENV1) in Angola was detected in 2013, while DENV serotype 2 (DENV2) was detected in 2018. Here, we report results from molecular and genomic investigations conducted at the Ministry of Health national reference laboratory (INIS) in Angola on suspected dengue cases detected between January 2017 and February 2019.MethodsA total of 401 serum samples from dengue suspected cases were collected in 13 of the 18 provinces in Angola. Of those, 351 samples had complete data for demographic and epidemiological analysis, including age, gender, province, type of residence, clinical symptoms, as well as dates of onset of symptoms and sample collection. RNA was extracted from residual samples and tested for DENV-RNA using two distinct real time RT-PCR protocols. On-site whole genome nanopore sequencing was performed on RT-PCR+ samples. Bayesian coalescent models were used to estimate date and origin of outbreak emergence, as well as population growth rates.ResultsMolecular screening showed that 66 out of 351 (19%) suspected cases were DENV-RNA positive across 5 provinces in Angola. DENV RT-PCR+ cases were detected more frequently in urban sites compared to rural sites. Of the DENV RT-PCR+ cases most were collected within 6 days of symptom onset. 93% of infections were confirmed by serotype-specific RT-PCR as DENV2 and 1 case (1.4%) was confirmed as DENV1. Six CHIKV RT-PCR+ cases were also detected during the study period, including 1 co-infection of CHIKV with DENV1. Most cases (87%) were detected in Luanda during the rainy season between April and October. Symptoms associated with severe dengue were observed in 11 patients, including 2 with a fatal outcome. On-site nanopore genome sequencing followed by genetic analysis revealed an introduction of DENV2 Cosmopolitan genotype (also known as DENV2-II genotype) possibly from India in or around October 2015, at least 1 year before its detection in the country. Coalescent models suggest relatively moderately rapid epidemic growth rates and doubling times, and a moderate expansion of DENV2 in Angola during the studied period.ConclusionThis study describes genomic, epidemiological and demographic characteristic of predominately urban transmission of DENV2 in Angola. We also find co-circulation of DENV2 with DENV1 and CHIKV and report several RT-PCR confirmed severe dengue cases in the country. Increasing dengue awareness in healthcare professional, expanding the monitorization of arboviral epidemics across the country, identifying most common mosquito breeding sites in urban settings, implementing innovative vector control interventions and dengue vaccination campaigns could help to reduce vector presence and DENV transmission in Angola. 相似文献
11.
Fusobacterium nucleatum strains, isolated from man and animals, were shown to comprise four centres of variation within the species by using a variety of biochemical tests. DNA-DNA hybridization data indicated that they should differences between the groups to warrant their placement into four subspecies for which we propose the following: F. nucleatum subsp. nucleatum (commonly isolated from diseased sites), F. nucleatum subsp. polymorphum (from healthy sites, most frequently isolated), F. nucleatum subsp. fusiforme (from healthy sites, most frequently isolated), F. nucleatum subsp. fusiforme (from healthy sites, rarely isolated) and F. nucleatum subsp. animalis from the colon of animals. 相似文献
12.
P.C. Coleman D.J.J. Potgieter C.H.Van Aswegen N.M.J. Vermeulent 《Phytochemistry》1984,23(5):1202-1203
Chromatographic separation of the ethanol extract of Geigeria burkei resulted in the isolation and characterization of two known flavonoids, 5,7,3′,4′-tetrahydroxy-6-methoxyflavone and 5,7,4'-trihydroxy-6 methoxyflavone. 13CNMR data, as well as the respiratory inhibition and uncoupling of oxidative phosphorylation, is reported for the first time. 相似文献
13.
Cross-protection against Marburg virus strains by using a live, attenuated recombinant vaccine
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Daddario-DiCaprio KM Geisbert TW Geisbert JB Ströher U Hensley LE Grolla A Fritz EA Feldmann F Feldmann H Jones SM 《Journal of virology》2006,80(19):9659-9666
Marburg virus (MARV) has been associated with sporadic episodes of hemorrhagic fever, including a recent highly publicized outbreak in Angola that produced severe disease and significant mortality in infected patients. MARV is also considered to have potential as a biological weapon. Recently, we reported the development of a promising attenuated, replication-competent vaccine against MARV based on recombinant vesicular stomatitis virus (VSV) expressing the glycoprotein of the Musoke strain of MARV (VSVDeltaG/MARVGP-Musoke). We used this vaccine to demonstrate complete protection of cynomolgus monkeys against a homologous MARV challenge. While these results are highly encouraging, an effective vaccine would need to confer protection against all relevant strains of MARV. Here, we evaluated the protective efficacy of the VSVDeltaG/MARVGP-Musoke vaccine against two heterologous MARV strains, the seemingly more pathogenic Angola strain and the more distantly related Ravn strain. In this study, seven cynomolgus monkeys were vaccinated with the VSVDeltaG/MARVGP-Musoke vector. Three of these animals were challenged with the Angola strain, three with the Ravn strain, and a single animal with the Musoke strain of MARV. Two animals served as controls and were each injected with a nonspecific VSV vector; these controls were challenged with the Angola and Ravn strains, respectively. Both controls succumbed to challenge by day 8. However, none of the specifically vaccinated animals showed any evidence of illness either from the vaccination or from the MARV challenges and all of these animals survived. These data suggest that the VSVDeltaG/MARVGP-Musoke vaccine should be sufficient to protect against all known MARV strains. 相似文献
14.
The association of Arbuscular Mycorrhizal Fungi (AMF) with three medicinally important plants viz., Eclipta prostrata, Indigofera aspalathoides, I. tinctoria collected from three different localities of Kanyakumari District, South India was examined. The study reports the colonization
percentage, diversity and species richness of different AM fungi in the rhizosphere of the three medicinal plants and discusses
the impact of soil physicochemical characteristics such as soil texture, pH and available macro- and micro nutrient content
on AM fungal communities. A total 21 AM fungal species were identified in field conditions of the three plants from three
sites. AM fungal species richness, colorization percentage and Shannon index were found to be high in the two Indigofera sp. growing in the hilly areas of Kanyakumari District and were low in E. prostrata collected from the damp regions in the foothills of the three study sites. Five species registered 100% frequency in all
the study sites of the three medicinally important plants with Glomus as the dominant genera. The study states that the mean colonization and diversity patterns were dependant on edaphic factors
and type of vegetation. 相似文献
15.
Angola’s intermittent 27‐year civil war displaced over four million people and decimated wildlife populations. During the 1980s, African elephants (Loxodonta africana Blumenbach) in Angola drew international alarm with reports of 100,000 elephants killed. Luiana Partial Reserve (PR), a conservation area in south‐east Angola, was the military operations centre for UNITA (National Union for the Total Independence of Angola), which used elephant ivory to pay for arms and meat. However, the full impact of the civil war on elephants is uncertain because there are no reliable estimates of Angolan elephant populations. Following the end of the civil war in 2002, our three aerial surveys of Luiana PR indicated that elephant numbers are increasing rapidly, from 366 in January 2004 to 1827 in November 2005, and expanding their range in the Reserve. Concurrently, elephants tagged with satellite collars in northern Botswana and the Caprivi Strip, Namibia, moved into Luiana PR. To facilitate re‐colonization and conservation of elephants and other wildlife in Luiana PR, we recommend: (i) realignment of the veterinary fence on the Botswana–Namibia border; (ii) development of effective land use management and anti‐poaching programmes; (iii) clearing of landmines; (iv) designation of the Reserve a national park; and (v) development of ecotourism and community conservation programmes. 相似文献
16.
This study examines the short- and long-term effects of war-induced and war-unrelated migration on fertility outcomes using data from two peri-urban municipalities of Greater Luanda in Angola. In the short term, results from multi-level discrete-time logistic regression models indicate that net of other factors, war-unrelated migration is associated with a lower probability of birth than war-induced migration in a given year. Similar results are obtained when the effects of migration are lagged by a year. At the same time, the effects of war-triggered migration do not differ significantly from those of not migrating in a given year but are statistically significant when the effects of migration are lagged by a year. In the long term, the effects of migration experience on cumulative fertility are negligible and not statistically significant net of demographic and socioeconomic variables. Interpretations of the results are offered in the context of Angola and their broader implications are reflected on. 相似文献
17.
Summary Using agarose gel electrophoresis, C'3 was typed in 4 populations. The gene frequencies of the common allele C'3S in these 4 populations were Germans (0.8071), Bulgarians (0.8149), Iranians (0.7920) and Angola (0.9532). The results are discussed.
Zusammenfassung Auf Grund der Aarosegel-Elektrophorese erfolgte die C'3-Bestimmung bei 4 Populationen. Die Genfrequenzen der bekannten Allele C'3S in diesen 4 Populationen waren von Deutschen (0,8071), Bulgaren (0,8149), Iranern (0,7920) und Negern (Angola, 0,9532). Die Ergebnisse werden diskutiert.相似文献
18.
Afraster scalariformis n.gen. et sp., from the Upper Cretaceous (Coniacian) of Angola, southwest Africa, is assigned to the Pedicellasterinae, a subfamily of the Asteriidae. An associated foraminiferal fauna is dominated by planktic species; also present are lagenids that are indicative of a shelf setting. The subfamily Pedicellasterinae is peculiar in that only two rows of podia are present, rather than the four typical of the family. Intimate association ofAfraster with oysters suggests the predatory habits typical of modern asteriids; general arm and disk arrangement also suggest such a behavior.Afraster is the first recorded fossil asteroid from Angola. 相似文献
19.
Olof Biström 《水生昆虫》2013,35(4):325-328
Uvarus pinheyi sp. n. is described from Zambia and Hydroglyphus pseudoctoguttatus sp. n. from Angola. Distinguishing characteristics are given for the new taxa. 相似文献
20.
Antje Günster 《Plant Ecology》1994,114(2):149-160
Plants growing in extreme habitats, such as deserts, are expected to show high plasticity (variability) in life history parameters to compensate for the unpredictability of their environment. In this study variability in life history parameters and possible sources of variability were investigated in four serotinous (= seed retaining) plant species from the Namib Desert.Blepharis grossa, Geigeria alata, Geigeria ornativa andPetalidium setosum were studied in a mosaic of spatio-temporal environmental conditions represented by three sites and three rain seasons. The coefficient of variation and whether or not significant differences occurred between environmental conditions were used to determine the most variable species and parameters. The most variable species was the strictly annualB. grossa, which might be related to its life form strategy and poor competitive ability as a pioneer species. Life history parameters which responded most frequently to varying environmental conditions were source pool, flowering time and seed production. Seedling density was influenced by the source pool and intensity of rainfall, seedling establishment by timing and intensity of rain events, as well as by seed mass. Although it was expected that high within population variability in life history parameters would also result in a response to differing environmental conditions, there was no direct correlation. Variable responses in life history parameters in most species were caused by differences in site condition as well as by differences in seasons, especially with regard to timing and intensity of rain events. 相似文献