On the Existence of the Quantum Action

We have previously proposed a conjecture stating that quantum mechanical transition amplitudes can be parametrized in terms of a quantum action. Here we give a proof of the conjecture and establish the existance of a local quantum action in the case of imaginary time in the Feynman-Kac limit (when temperature goes to zero). Moreover we discuss some symmetry properties of the quantum action.Comment: revised version, Text (LaTeX

Maximal quadratic modules on *-rings

We generalize the notion of and results on maximal proper quadratic modules from commutative unital rings to $\ast$-rings and discuss the relation of this generalization to recent developments in noncommutative real algebraic geometry. The simplest example of a maximal proper quadratic module is the cone of all positive semidefinite complex matrices of a fixed dimension. We show that the support of a maximal proper quadratic module is the symmetric part of a prime $\ast$-ideal, that every maximal proper quadratic module in a Noetherian $\ast$-ring comes from a maximal proper quadratic module in a simple artinian ring with involution and that maximal proper quadratic modules satisfy an intersection theorem. As an application we obtain the following extension of Schm\" udgen's Strict Positivstellensatz for the Weyl algebra: Let $c$ be an element of the Weyl algebra $\mathcal{W}(d)$ which is not negative semidefinite in the Schr\" odinger representation. It is shown that under some conditions there exists an integer $k$ and elements $r_1,...,r_k \in \mathcal{W}(d)$ such that $\sum_{j=1}^k r_j c r_j^\ast$ is a finite sum of hermitian squares. This result is not a proper generalization however because we don't have the bound $k \le d$.Comment: 11 page

Three principles for co-designing sustainability intervention strategies : Experiences from Southern Transylvania

Transformational research frameworks provide understanding and guidance for fostering change towards sustainability. They comprise stages of system understanding, visioning and co-designing intervention strategies to foster change. Guidance and empirical examples for how to facilitate the process of co-designing intervention strategies in real-world contexts remain scarce, especially with regard to integrating local initiatives. We suggest three principles to facilitate the process of co-designing intervention strategies that integrate local initiatives: (1) Explore existing and envisioned initiatives fostering change towards the desired future; (2) Frame the intervention strategy to bridge the gap between the present state and desired future state(s), building on, strengthening and complementing existing initiatives; (3) Identify drivers, barriers and potential leverage points for how to accelerate progress towards sustainability. We illustrate our approach via a case study on sustainable development in Southern Transylvania. We conclude that our principles were useful in the case study, especially with regards to integrating initiatives, and could also be applied in other real-world contexts.Peer reviewe

Wigner Crystalization in the Lowest Landau Level for ν≥1/5\nu \ge 1/5

By means of exact diagonalization we study the low-energy states of seven electrons in the lowest Landau level which are confined by a cylindric external potential modelling the rest of a macroscopic system and thus controlling the filling factor $\nu$. Wigner crystal is found to be the ground state for filling factors between $\nu = 1/3$ and $\nu = 1/5$ provided electrons interact via the bare Coulomb potential. Even at $\nu =1/5$ the solid state has lower energy than the Laughlin's one, although the two energies are rather close. We also discuss the role of pseudopotential parameters in the lowest Landau level and demonstrate that the earlier reported gapless state, appearing when the short-range part of the interaction is suppressed, has nothing in common with the Wigner crystalization in pure Coulomb case.Comment: 9 pages, LaTex, 8 figure

Efficiency of the Incomplete Enumeration algorithm for Monte-Carlo simulation of linear and branched polymers

We study the efficiency of the incomplete enumeration algorithm for linear and branched polymers. There is a qualitative difference in the efficiency in these two cases. The average time to generate an independent sample of $n$ sites for large $n$ varies as $n^2$ for linear polymers, but as $exp(c n^{\alpha})$ for branched (undirected and directed) polymers, where $0<\alpha<1$. On the binary tree, our numerical studies for $n$ of order $10^4$ gives $\alpha = 0.333 \pm 0.005$. We argue that $\alpha=1/3$ exactly in this case.Comment: replaced with published versio

Gauge dependence of effective action and renormalization group functions in effective gauge theories

The Caswell-Wilczek analysis on the gauge dependence of the effective action and the renormalization group functions in Yang-Mills theories is generalized to generic, possibly power counting non renormalizable gauge theories. It is shown that the physical coupling constants of the classical theory can be redefined by gauge parameter dependent contributions of higher orders in $\hbar$ in such a way that the effective action depends trivially on the gauge parameters, while suitably defined physical beta functions do not depend on those parameters.Comment: 13 pages Latex file, additional comments in section

A pleurocidin analogue with greater conformational flexibility, enhanced antimicrobial potency and in vivo therapeutic efficacy.

Antimicrobial peptides (AMPs) are a potential alternative to classical antibiotics that are yet to achieve a therapeutic breakthrough for treatment of systemic infections. The antibacterial potency of pleurocidin, an AMP from Winter Flounder, is linked to its ability to cross bacterial plasma membranes and seek intracellular targets while also causing membrane damage. Here we describe modification strategies that generate pleurocidin analogues with substantially improved, broad spectrum, antibacterial properties, which are effective in murine models of bacterial lung infection. Increasing peptide-lipid intermolecular hydrogen bonding capabilities enhances conformational flexibility, associated with membrane translocation, but also membrane damage and potency, most notably against Gram-positive bacteria. This negates their ability to metabolically adapt to the AMP threat. An analogue comprising D-amino acids was well tolerated at an intravenous dose of 15 mg/kg and similarly effective as vancomycin in reducing EMRSA-15 lung CFU. This highlights the therapeutic potential of systemically delivered, bactericidal AMPs

Resummation of the hadronic tau decay width with the modified Borel transform method

A modified Borel transform of the Adler function is used to resum the hadronic tau decay width ratio. In contrast to the ordinary Borel transform, the integrand of the Borel integral is renormalization--scale invariant. We use an ansatz which explicitly accounts for the structure of the leading infrared renormalon. Further, we use judiciously chosen conformal transformations for the Borel variable, in order to map sufficiently away from the origin the other ultraviolet and infrared renormalon singularities. In addition, we apply Pade approximants for the corresponding truncated perturbation series of the modified Borel transform, in order to further accelerate the convergence. Comparing the results with the presently available experimental data on the tau hadronic decay width ratio, we obtain $\alpha_s(M^z) = 0.1192 +- 0.0007_{exp.} +- 0.0010_{EW+CKM} +- 0.0009_{th.} +- 0.0003_{evol.}$. These predictions virtually agree with those of our previous resummations where we used ordinary Borel transforms instead.Comment: 32 pages, 2 eps-figures, revtex; minor changes in the formulations; a typo in Eq.(47) corrected; version as appearing in Phys. Rev.

B-cell dysregulation in Crohn's disease is partially restored with infliximab therapy

Background: B-cell depletion can improve a variety of chronic inflammatory diseases, but does not appear beneficial for patients with Crohn's disease. Objective: To elucidate the involvement of B cells in Crohn's disease, we here performed an 'in depth' analysis of intestinal and blood B-cells in this chronic inflammatory disease. Methods: Patients with Crohn's disease were recruited to study B-cell infiltrates in intestinal biopsies (n = 5), serum immunoglobulin levels and the phenotype and molecular characteristics of blood B-cell subsets (n = 21). The effects of infliximab treatment were studied in 9 patients. Results: Granulomatous tissue showed infiltrates of B lymphocytes rather than Ig-secreting plasma cells. Circulating transitional B cells and CD21low B cells were elevated. IgM memory B cells were reduced and natural effector cells showed decreased replication histories and somatic hypermutation (SHM) levels. In contrast, IgG and IgA memory B cells were normally present and their Ig gene transcripts carried increased SHM levels. The numbers of transitional and natural effector cells were normal in patients who responded clinically well to infliximab. Conclusions: B cells in patients with Crohn's disease showed signs of chronic stimulation with localization to granulomatous tissue and increased molecular maturation of IgA and IgG. Therapy with TNFα-blockers restored the defect in IgM memory B-cell generation and normalized transitional B-cell levels, making these subsets candidate markers for treatment monitoring. Together, these results suggest a chronic, aberrant B-cell response in patients with Crohn's disease, which could be targeted with new therapeutics that specifically regulate B-cell function

Intra-arterial peptide-receptor radionuclide therapy for neuro-endocrine tumour liver metastases:an in-patient randomised controlled trial (LUTIA)

Purpose: Peptide receptor radionuclide therapy (PRRT) using [177Lu]Lu-DOTATATE has been shown to effectively prolong progression free survival in grade 1–2 gastroenteropancreatic neuroendocrine tumours (GEP-NET), but is less efficacious in patients with extensive liver metastases. The aim was to investigate whether tumour uptake in liver metastases can be enhanced by intra-arterial administration of [177Lu]Lu-DOTATATE into the hepatic artery, in order to improve tumour response without increasing toxicity. Methods: Twenty-seven patients with grade 1–2 GEP-NET, and bi-lobar liver metastases were randomized to receive intra-arterial PRRT in the left or right liver lobe for four consecutive cycles. The contralateral liver lobe and extrahepatic disease were treated via a “second-pass” effect and the contralateral lobe was used as the control lobe. Up to three metastases (&gt; 3 cm) per liver lobe were identified as target lesions at baseline on contrast-enhanced CT. The primary endpoint was the tumour-to-non-tumour (T/N) uptake ratio on the 24 h post-treatment [177Lu]Lu-SPECT/CT after the first cycle. This was calculated for each target lesion in both lobes using the mean uptake. T/N ratios in both lobes were compared using paired-samples t-test. Findings: After the first cycle, a non-significant difference in T/N uptake ratio was observed: T/NIA = 17·4 vs. T/Ncontrol = 16·2 (p = 0·299). The mean increase in T/N was 17% (1·17; 95% CI [1·00; 1·37]). Of all patients, 67% (18/27) showed any increase in T/N ratio after the first cycle. Conclusion: Intra-arterial [177Lu]Lu-DOTATATE is safe, but does not lead to a clinically significant increase in tumour uptake.</p