Institution
University of Zimbabwe
Education•Harare, Harare, Zimbabwe•
About: University of Zimbabwe is a education organization based out in Harare, Harare, Zimbabwe. It is known for research contribution in the topics: Population & Acquired immunodeficiency syndrome (AIDS). The organization has 4378 authors who have published 6800 publications receiving 160720 citations. The organization is also known as: UZ & University College of Rhodesia and Nyasaland.
Topics: Population, Acquired immunodeficiency syndrome (AIDS), Agriculture, Health care, Public health
Papers published on a yearly basis
Papers
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National University of Río Negro1, Naturalis2, Institut national de la recherche agronomique3, Food and Agriculture Organization4, Federal University of Bahia5, Federal University of Ceará6, National University of Comahue7, Pontifícia Universidade Católica do Rio Grande do Sul8, Bogor Agricultural University9, National University of Colombia10, Universidade Federal de Sergipe11, Empresa Brasileira de Pesquisa Agropecuária12, State University of Norte Fluminense13, University of Zimbabwe14, National Agricultural Research Centre15, University of Cape Coast16, University of Brawijaya17, University of São Paulo18, Stellenbosch University19
TL;DR: This study quantifies to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America.
Abstract: Ecological intensification, or the improvement of crop yield through enhancement of biodiversity, may be a sustainable pathway toward greater food supplies. Such sustainable increases may be especially important for the 2 billion people reliant on small farms, many of which are undernourished, yet we know little about the efficacy of this approach. Using a coordinated protocol across regions and crops, we quantify to what degree enhancing pollinator density and richness can improve yields on 344 fields from 33 pollinator-dependent crop systems in small and large farms from Africa, Asia, and Latin America. For fields less than 2 hectares, we found that yield gaps could be closed by a median of 24% through higher flower-visitor density. For larger fields, such benefits only occurred at high flower-visitor richness. Worldwide, our study demonstrates that ecological intensification can create synchronous biodiversity and yield outcomes.
332 citations
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TL;DR: Time spent looking varied with position within the group; this effect was strongest in closed habitats, where central animals tended to scan least and feed most, and within species, animals inclosed habitats, those with dense vegetation, tended to spend more time in looking than did animals in the open.
Abstract: African antelope may devote a large proportion of their foraging time to looking around. The factors affecting such vigilance behaviour are examined for grazing antelope, five species being studied in detail. The proportion of time spent looking decreased as species body weight increased. Within species, animals in closed habitats, those with dense vegetation, tended to spend more time in looking than did animals in the open. There was some evidence that vigilance, presumably for predators, was shared by group members, but in one species, impala, vigilance apparently increased with group size and with proximity to neighbours. Time spent looking varied with position within the group; this effect was strongest in closed habitats, where central animals tended to scan least and feed most. Vigilance increased as feeding success decreased, partly due to mutual interference between looking and feeding. The possible social, foraging and predator-detection values of vigilance are discussed. A simple model is introduced to help explain the effects of cover and to facilitate further discussion.
326 citations
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TL;DR: It is demonstrated that endogenous oscillations in sugar levels provide metabolic feedback to the circadian oscillator through the morning-expressed gene PSEUDO-RESPONSE REGULATOR 7 (PRR7), and that prr7 mutants are insensitive to the effects of sucrose on the circadian period.
Abstract: Circadian clocks provide a competitive advantage in an environment that is heavily influenced by the rotation of the Earth, by driving daily rhythms in behaviour, physiology and metabolism in bacteria, fungi, plants and animals. Circadian clocks comprise transcription-translation feedback loops, which are entrained by environmental signals such as light and temperature to adjust the phase of rhythms to match the local environment. The production of sugars by photosynthesis is a key metabolic output of the circadian clock in plants. Here we show that these rhythmic, endogenous sugar signals can entrain circadian rhythms in Arabidopsis thaliana by regulating the gene expression of circadian clock components early in the photoperiod, thus defining a 'metabolic dawn'. By inhibiting photosynthesis, we demonstrate that endogenous oscillations in sugar levels provide metabolic feedback to the circadian oscillator through the morning-expressed gene PSEUDO-RESPONSE REGULATOR 7 (PRR7), and we identify that prr7 mutants are insensitive to the effects of sucrose on the circadian period. Thus, photosynthesis has a marked effect on the entrainment and maintenance of robust circadian rhythms in A. thaliana, demonstrating that metabolism has a crucial role in regulation of the circadian clock.
322 citations
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TL;DR: In this paper, detrital zircon grains from Archaean quartzites from the Mweza and Shurugwi greenstone belts have been dated by the ion probe SHRIMP.
Abstract: 86 detrital zircon grains from Archaean quartzites from the Mweza and Shurugwi greenstone belts have been dated by the ion probe SHRIMP. Nine of these give ages of 3.75–3.80 Ga, older than any Zimbabwean rocks so far satisfactorily dated, and the Tokwe-Zvishavane gneisses are a possible source for these old grains. However, none are comparable in age with the 4.2 Ga zircons discovered in Western Australia. If such old grains exist in the sample it is unlikely (P>0.05) that their abundance could exceed 3%. Ages of the younger grains are broadly consistent with the presumed age of the quartzites sampled, though some high Th/U grains in the Shurugwi sample may be anomalously young.
317 citations
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TL;DR: In this article, the authors used panel data to investigate responses of one set of households to the risk of a major droughts in rural households in Zimbabwe and found that the main private coping mechanism is the sale of cattle.
314 citations
Authors
Showing all 4433 results
Name | H-index | Papers | Citations |
---|---|---|---|
Didier Raoult | 173 | 3267 | 153016 |
Roy M. Anderson | 116 | 526 | 65549 |
Vikram Patel | 116 | 654 | 59717 |
Richard M. Cowling | 96 | 392 | 30042 |
Ken E. Giller | 92 | 555 | 36374 |
Leif Bertilsson | 87 | 321 | 23933 |
Johan Rockström | 85 | 236 | 57842 |
Alex Aiken | 77 | 295 | 20254 |
Frances M. Cowan | 76 | 456 | 19984 |
Robert J. Biggar | 73 | 231 | 18474 |
Charles A. Thornton | 71 | 182 | 17195 |
David Wilson | 69 | 618 | 18780 |
David Katzenstein | 69 | 280 | 21239 |
Bruce M. Campbell | 67 | 227 | 17616 |
David Sanders | 65 | 492 | 17119 |