1,464 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
Domain walls inside localised orientifolds
The equations of motion of toroidal orientifold compactifications with fluxes
are in one-to-one correspondence with gauged supergravity if the orientifold
(and D-brane) sources are smeared over the compact space. This smeared limit is
identical to the approximation that ignores warping. It is therefore relevant
to compare quantities obtained from the gauged supergravity with the true 10d
solution with localised sources. In this paper we find the correspondence
between BPS domain walls in gauged SUGRA and 10D SUGRA with localised sources.
Our model is the simplest orientifold with fluxes we are aware of: an O6/D6
compactification on T^3/Z_2 in massive IIA with H_3-flux. The BPS domain walls
correspond to a O6/D6/NS5/D8 bound state. Our analysis reveals that the domain
wall energy computed in gauged SUGRA is unaffected by the localisation of the
O6/D6 sources.Comment: 26 pages, 1 figur
Feasibility study for reliable magnetic connection switch, phase I Final report
Feasibility of magnetic circuits for high reliability computer switche
Leeftijdsbepaling van kokkels uit de Oosterschelde 1998 en 2000
Ter onderbouwing van het beleid voor de kokkelvisserij in schelpdier-arme jaren wordt sinds 1990 in opdracht van het ministerie van Landbouw, Natuurbeheer en Visserij (LNV) door het RIVO-CSO jaarlijks het kokkelbestand (Cerastoderma edule) in de Oosterschelde, de Westerschelde en de Waddenzee geĂŻnventariseerd. De kokkelbestandsopnames worden in het voorjaar uitgevoerd. In een aantal jaren is ook een bestandsopname in het najaar uitgevoerd. Daarnaast is in 1991 door het RIVO-CSO, onafhankelijk van de surveys, een onderzoek opgezet naar de groei en sterfte van kokkelbestanden in de Oosterschelde en in de Westerschelde. Dit onderzoek is opgezet om meer inzicht te krijgen in de factoren die van invloed kunnen zijn op de ontwikkeling van kokkelbestanden
Promoting students’ sexual and reproductive health in peer-led programmes at two South African universities: Emergent tensions and dilemmas
Sexual and reproductive health programmes with students in higher education in South Africa, are a neglected area of intervention. We report on piloting the peer-facilitated Auntie Stella intervention material at two South African universities. This participatory methodology encourages critical thinking by opening discussion on managing relationships, sexual decision-making, gender-based violence and risk-safety. The format involves various cards featuring a letter, a facilitated discussion, an answer-response and action points. Six focus groups of participants were facilitated by postgraduate students over four months. Using thematic analysis four tensions were identified in the student discussions: HIV awareness was in tension with relationship practices; awareness of risk was in tension with denial of vulnerability; awareness of individuals’ rights was in tension with claims on these rights; and HIV knowledge was in tension with HIV stigma. The Auntie Stella material has the potential to open up discursive spaces amongst students, and to develop agency in sexual decision-making
Instantons and wormholes in AdS(3) x S-3 x CY2
We study supergravity instantons sourced by axion (and saxion) fields in the Euclidean AdS(3) x S-3 x CY2 vacua of IIB supergravity. Such instantons are described by geodesic curves on the moduli space; the timelike geodesics can describe Euclidean wormholes, the lightlike geodesics describe (generalizations of) D instantons, and spacelike geodesics are subextremal versions thereof. We perform a concrete classification of such geodesics and find that, despite earlier claims, the wormholes fail to be regular. A subclass of the lightlike geodesics is supersymmetric and, up to dualities, lifts to Euclidean strings wrapping 2-cycles in the CY2. The dual of these instantons is expected to be worldsheet instantons of the D1-D5 conformal field theory
New possibilities on transplanting kidneys from hepatitis C virus positive donors: a Systematic Review
Incisional Hernia: An Experimental and Clinical Study
__Abstract__
Incisional hernia is one of the most common long-term complications of abdominal surgery.
In prospective studies with sufficient follow-up, incidences of incisional hernia after
laparotomy up to 20% are reported.
Incisional hernia can be defined as an internal abdominal wall defect that develops after a
previously closed laparotomy. Intra-abdominal organs such as omentum, bowel or bladder
may protrude through the fascial defect, covered by a peritoneal sac and intact skin.
If a rupture of the abdominal wall occurs within the first postoperative days, when the ski
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