194 research outputs found
Recollements of Module Categories
We establish a correspondence between recollements of abelian categories up
to equivalence and certain TTF-triples. For a module category we show,
moreover, a correspondence with idempotent ideals, recovering a theorem of
Jans. Furthermore, we show that a recollement whose terms are module categories
is equivalent to one induced by an idempotent element, thus answering a
question by Kuhn.Comment: Comments are welcom
Real-time data coupling for hybrid testing in a geotechnical centrifuge
Geotechnical centrifuge models necessarily involve simplifications compared to the full-scale scenario under investigation. In particular, structural systems (e.g. buildings or foundations) generally can’t be replicated such that complex full-scale characteristics are obtained. Hybrid testing offers the ability to combine capabilities from physical and numerical modelling to overcome some of the experimental limitations. In this paper, the development of a coupled centrifuge-numerical model (CCNM) pseudo-dynamic hybrid test for the study of tunnel-building interaction is presented. The methodology takes advantage of the relative merits of centrifuge tests (modelling soil behaviour and soil-pile interactions) and numerical simulations (modelling building deformations and load redistribution), with pile load and displacement data being passed in real-time between the two model domains. To appropriately model the full-scale scenario, a challenging force-controlled system was developed (the first of its kind for hybrid testing in a geotechnical centrifuge). The CCNM application can accommodate simple structural frame analyses as well as more rigorous simulations conducted using the finite element analysis software ABAQUS, thereby extending the scope of application to non-linear structural behaviour. A novel data exchange method between ABAQUS and LabVIEW is presented which provides a significant enhancement compared to similar hybrid test developments. Data are provided from preliminary tests which highlight the capabilities of the system to accurately model the global tunnel-building interaction problem
Struktur und Entwicklung des Oberrheingrabens als europäischer Wirtschaftsstandort - Kurzfassung
In dieser Arbeit wird die ökonomische Situation des Oberrheingrabens anhand der Themenbereiche Beschäftigung und Arbeitslosigkeit, Forschung und Entwicklung, Wachstum und Produktivität und Unternehmensgründungen analysiert. Zudem werden die wichtigsten infrastrukturellen Rahmenbedingungen, die Bevölkerungsentwicklung und Unterschiede in der Besteuerung und in den Genehmigungsverfahren innerhalb des trinationalen Oberrheingrabens dargestellt. Darauf aufbauend wird das Potential und die mögliche Rolle der
Region als europäischer Wirtschaftsstandort diskutiert.
Die Untersuchung entstand in Zusammenarbeit zwischen dem Institut für angewandte Wirtschaftsforschung, IAW, in Tübingen, der Konjunkturforschung Basel AG, BAK, in Basel und
dem Zentrum für Europäische Wirtschaftsforschung, ZEW, in Mannheim. Dabei übernahm das IAW die Untersuchung der Bevölkerungsentwicklung, des Arbeitsmarktes, der Gewerbeflächen und des Wohnungsmarktes. Das BAK untersuchte das regionale Wachstum, die
Produktivitätsentwicklung und die nationalen Genehmigungsverfahren. Die Kapitel über die
Verkehrsinfrastruktur, die Besteuerung der Unternehmen, Forschung und Entwicklung und
Unternehmensgründungen wurden vom ZEW erstellt. Die Schlußfolgerungen wurden gemeinsam von den drei Instituten erarbeitet
Criteria for flatness and injectivity
Let be a commutative Noetherian ring. We give criteria for flatness of
-modules in terms of associated primes and torsion-freeness of certain
tensor products. This allows us to develop a criterion for regularity if
has characteristic , or more generally if it has a locally contracting
endomorphism. Dualizing, we give criteria for injectivity of -modules in
terms of coassociated primes and (h-)divisibility of certain \Hom-modules.
Along the way, we develop tools to achieve such a dual result. These include a
careful analysis of the notions of divisibility and h-divisibility (including a
localization result), a theorem on coassociated primes across a \Hom-module
base change, and a local criterion for injectivity.Comment: 19 page
Struktur und Entwicklung des Oberrheingrabens als europäischer Wirtschaftsstandort: Zurzfassung
In dieser Arbeit wird die ökonomische Situation des Oberrheingrabens anhand der Themenbereiche Beschäftigung und Arbeitslosigkeit, Forschung und Entwicklung, Wachstum und Produktivität und Unternehmensgründungen analysiert. Zudem werden die wichtigsten infrastrukturellen Rahmenbedingungen, die Bevölkerungsentwicklung und Unterschiede in der Besteuerung und in den Genehmigungsverfahren innerhalb des trinationalen Oberrheingrabens dargestellt. Darauf aufbauend wird das Potential und die mögliche Rolle der Region als europäischer Wirtschaftsstandort diskutiert. Die Untersuchung entstand in Zusammenarbeit zwischen dem Institut für angewandte Wirtschaftsforschung, IAW, in Tübingen, der Konjunkturforschung Basel AG, BAK, in Basel und dem Zentrum für Europäische Wirtschaftsforschung, ZEW, in Mannheim. Dabei übernahm das IAW die Untersuchung der Bevölkerungsentwicklung, des Arbeitsmarktes, der Gewerbeflächen und des Wohnungsmarktes. Das BAK untersuchte das regionale Wachstum, die Produktivitätsentwicklung und die nationalen Genehmigungsverfahren. Die Kapitel über die Verkehrsinfrastruktur, die Besteuerung der Unternehmen, Forschung und Entwicklung und Unternehmensgründungen wurden vom ZEW erstellt. Die Schlußfolgerungen wurden gemeinsam von den drei Instituten erarbeitet. --
Mesoscopic models for DNA stretching under force: new results and comparison to experiments
Single molecule experiments on B-DNA stretching have revealed one or two
structural transitions, when increasing the external force. They are
characterized by a sudden increase of DNA contour length and a decrease of the
bending rigidity. It has been proposed that the first transition, at forces of
60--80 pN, is a transition from B to S-DNA, viewed as a stretched duplex DNA,
while the second one, at stronger forces, is a strand peeling resulting in
single stranded DNAs (ssDNA), similar to thermal denaturation. But due to
experimental conditions these two transitions can overlap, for instance for
poly(dA-dT). We derive analytical formula using a coupled discrete worm like
chain-Ising model. Our model takes into account bending rigidity, discreteness
of the chain, linear and non-linear (for ssDNA) bond stretching. In the limit
of zero force, this model simplifies into a coupled model already developed by
us for studying thermal DNA melting, establishing a connexion with previous
fitting parameter values for denaturation profiles. We find that: (i) ssDNA is
fitted, using an analytical formula, over a nanoNewton range with only three
free parameters, the contour length, the bending modulus and the monomer size;
(ii) a surprisingly good fit on this force range is possible only by choosing a
monomer size of 0.2 nm, almost 4 times smaller than the ssDNA nucleobase
length; (iii) mesoscopic models are not able to fit B to ssDNA (or S to ss)
transitions; (iv) an analytical formula for fitting B to S transitions is
derived in the strong force approximation and for long DNAs, which is in
excellent agreement with exact transfer matrix calculations; (v) this formula
fits perfectly well poly(dG-dC) and -DNA force-extension curves with
consistent parameter values; (vi) a coherent picture, where S to ssDNA
transitions are much more sensitive to base-pair sequence than the B to S one,
emerges.Comment: 14 pages, 9 figure
Clinical relevance of genetic instability in prostatic cells obtained by prostatic massage in early prostate cancer
We investigated whether genetic lesions such as loss of heterozygosity (LOH) are detected in prostatic cells obtained by prostatic massage during early diagnosis of prostate cancer (CaP) and discussed their clinical relevance. Blood and first urine voided after prostatic massage were collected in 99 patients with total prostate-specific antigen (PSA) between 4 and 10 ng ml−1, prior to prostate biopsies. Presence of prostatic cells was confirmed by quantitative RT–PCR analysis of PSA mRNA. Genomic DNA was analysed for LOH on six chromosomal regions. One or more allelic deletions were found in prostatic fluid from 57 patients analysed, of whom 33 (58%) had CaP. Sensitivity and specificity of LOH detection and PSA free to total ratio <15% for positive biopsy were respectively 86.7 and 44% (P=0.002) for LOH, and 55 and 74% (P=0.006) for PSA ratio <15%. Analysis of LOH obtained from prostatic tumours revealed similar patterns compared to prostatic fluid cells in 86% of cases, confirming its accuracy. The presence of LOH of urinary prostatic cells obtained after prostatic massage is significantly associated with CaP on biopsy and may potentially help to identify a set of patients who are candidates for further prostate biopsies
Magnetic crystals and helical liquids in alkaline-earth fermionic gases
The joint action of a synthetic gauge potential and of atomic contact repulsion in a one-dimensional alkaline-earth(-like) fermionic gas with nuclear spin I leads to the existence of a hierarchy of fractional insulating and conducting states with intriguing properties. We unveil the existence and the features of those phases by means of both analytical bosonization techniques and numerical methods based on the density-matrix renormalization group algorithm. In particular, we show that the gapless phases can support helical modes, whereas the gapped states, which appear under certain conditions, are characterised both by density and magnetic order. Several distinct features emerge solely for spin I larger than 1/2, thus making their study with cold-atoms unique. We will finally argue that these states are related to the properties of an unconventional fractional quantum Hall effect in the thin-torus limit. The properties of this hierarchy of states can be experimentally studied in state-of-the-art cold-atom laboratories
Doxycycline versus prednisolone as an initial treatment strategy for bullous pemphigoid: a pragmatic non-inferiority randomised controlled trial
Background: Bullous pemphigoid (BP) is a blistering skin disorder with increased mortality. We tested whether a strategy of starting treatment with doxycycline conveys acceptable short-term blister control whilst conferring long-term safety advantages over starting treatment with oral corticosteroids.
Methods: Pragmatic multi-centre parallel-group randomised controlled trial of adults with BP (≥3 blisters ≥2 sites and linear basement membrane IgG/C3) plus economic evaluation. Participants were randomised to doxycycline (200 mg/day) or prednisolone (0·5 mg/kg/day). Localised adjuvant potent topical corticosteroids (<30 g/week) was permitted weeks 1-3. The non-inferiority primary effectiveness outcome was the proportion of participants with ≤3 blisters at 6 weeks. We assumed that doxycycline would be 25% less effective than corticosteroids with a 37% acceptable margin of noninferiority. The primary safety outcome was the proportion with severe, life-threatening or fatal treatment-related adverse events by 52 weeks. Analysis used a regression model adjusting for baseline disease severity, age and Karnofsky score, with missing data imputed.
Results: 132 patients were randomised to doxycycline and 121 to prednisolone from 54 UK and 7 German dermatology centres. Mean age was 77·7 years and 68.4% had moderate to severe baseline disease. For those starting doxycycline, 83/112 (74·1%) had ≤3 blisters at 6 weeks compared with 92/101 (91·1%) for prednisolone, a difference of 18·6% favouring prednisolone (upper limit of 90% CI, 26·1%, within the predefined 37% margin). Related severe, life-threatening and fatal events at 52 weeks were 18·5% for those starting doxycycline and 36·6% for prednisolone (mITT analysis), an adjusted difference of 19·0% (95% CI, 7·9%, 30·1%, p=0·001).
Conclusions: A strategy of starting BP patients on doxycycline is non-inferior to standard treatment with oral prednisolone for short-term blister control and significantly safer long-term
- …