1,536 research outputs found
AdS vacua with scale separation from IIB supergravity
Only two kinds of compactification are known that lead to four-dimensional
supersymmetric AdS vacua with moduli stabilisation and separation of scales at
tree-level. The most studied ones are compactifications of massive IIA
supergravity on SU(3) structures with smeared O6 planes, for which a general
ten-dimensional expression for the solution in terms of the SU(3) structure was
found. Less studied are compactifications of IIB supergravity with smeared
O5/O7 planes. In this paper we derive a general ten-dimensional expression for
the smeared O5/O7 solutions in terms of SU(2) structures. For a specific choice
of orientifold projections, we recover the known examples and we also provide
new explicit solutions.Comment: 27 + 16 pages; v2 references added and typos in few equations
correcte
Analysing Southern African food security: assessing the New Variant Famine hypothesis
This article investigates the New Variant Famine (NVF) hypothesis coined by Alex De Waal during the 2001-2003 Southern African food security crisis, as a tool for analysing food insecurity in the region. The NVF hypothesis depicts a protracted and extensive famine from which there is very little chance of recovery, in which HIV and AIDS are central to the widespread suffering of people. The author suggests that the role of HIV and AIDS on food security be considered as one contributing factor to a dynamic process(es) of vulnerability and not viewed in isolation. In addition it is suggested that analyses focus on underlying processes driving vulnerability and not on specific instances of “famine” or crisis
Systematic reviews of complementary therapies - an annotated bibliography. Part 1: Acupuncture
Background Complementary therapies are widespread but controversial. We aim to provide a comprehensive collection and a summary of systematic reviews of clinical trials in three major complementary therapies (acupuncture, herbal medicine, homeopathy). This article is dealing with acupuncture. Potentially relevant reviews were searched through the register of the Cochrane Complementary Medicine Field, the Cochrane Library, Medline, and bibliographies of articles and books. To be included articles had to review prospective clinical trials of acupuncture; had to describe review methods explicitly; had to be published; and had to focus on treatment effects. Information on conditions, interventions, methods, results and conclusions was extracted using a pretested form and summarized descriptively. Results From a total of 48 potentially relevant reviews preselected in a screeening process 39 met the inclusion criteria. 22 were on various pain syndromes or rheumatic diseases. Other topics addressed by more than one review were addiction, nausea, asthma and tinnitus. Almost unanimously the reviews state that acupuncture trials include too few patients. Often included trials are heterogeneous regarding patients, interventions and outcome measures, are considered to have insufficient quality and contradictory results. Convincing evidence is available only for postoperative nausea, for which acupuncture appears to be of benefit, and smoking cessation, where acupuncture is no more effective than sham acupuncture. Conclusions A large number of systematic reviews on acupuncture exists. What is most obvious from these reviews is the need for (the funding of) well-designed, larger clinical trials
Systematic reviews of complementary therapies – an annotated bibliography. Part 2: Herbal medicine
Background Complementary therapies are widespread but controversial. We aim to provide a comprehensive collection and a summary of systematic reviews of clinical trials in three major complementary therapies (acupuncture, herbal medicine, homeopathy). This article is dealing with herbal medicine. Potentially relevant reviews were searched through the register of the Cochrane Complementary Medicine Field, the Cochrane Library, Medline, and bibliographies of articles and books. To be included articles had to review prospective clinical trials of herbal medicines; had to describe review methods explicitly; had to be published; and had to focus on treatment effects. Information on conditions, interventions, methods, results and conclusions was extracted using a pre-tested form and summarized descriptively. Results From a total of 79 potentially relevant reviews pre-selected in the screening process 58 met the inclusion criteria. Thirty of the reports reviewed ginkgo (for dementia, intermittent claudication, tinnitus, and macular degeneration), hypericum (for depression) or garlic preparations (for cardiovascular risk factors and lower limb atherosclerosis). The quality of primary studies was criticized in the majority of the reviews. Most reviews judged the available evidence as promising but definitive conclusions were rarely possible. Conclusions Systematic reviews are available on a broad range of herbal preparations prescribed for defined conditions. There is very little evidence on the effectiveness of herbalism as practised by specialist herbalists who combine herbs and use unconventional diagnosis
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