The Shield that Never Was: Societies with Single-Peaked Preferences are More Open to Manipulation and Control

Much work has been devoted, during the past twenty years, to using complexity to protect elections from manipulation and control. Many results have been obtained showing NP-hardness shields, and recently there has been much focus on whether such worst-case hardness protections can be bypassed by frequently correct heuristics or by approximations. This paper takes a very different approach: We argue that when electorates follow the canonical political science model of societal preferences the complexity shield never existed in the first place. In particular, we show that for electorates having single-peaked preferences, many existing NP-hardness results on manipulation and control evaporate.Comment: 38 pages, 2 figure

Cold atoms in non-Abelian gauge potentials: From the Hofstadter "moth" to lattice gauge theory

We demonstrate how to create artificial external non-Abelian gauge potentials acting on cold atoms in optical lattices. The method employs $n$ internal states of atoms and laser assisted state sensitive tunneling. Thus, dynamics are communicated by unitary $n\times n$-matrices. By experimental control of the tunneling parameters, the system can be made truly non-Abelian. We show that single particle dynamics in the case of intense U(2) vector potentials lead to a generalized Hofstadter butterfly spectrum which shows a complex ``moth''-like structure. We discuss the possibility to employ non-Abelian interferometry (Aharonov-Bohm effect) and address methods to realize matter dynamics in specific classes of lattice gauge fields.Comment: 5 pages, 3 figure

Chiral crystals in strong-coupling lattice QCD at nonzero chemical potential

We study the effective action for strong-coupling lattice QCD with one-component staggered fermions in the case of nonzero chemical potential and zero temperature. The structure of this action suggests that at large chemical potentials its ground state is a crystalline `chiral density wave' that spontaneously breaks chiral symmetry and translation invariance. In mean-field theory, on the other hand, we find that this state is unstable. We show that lattice artifacts are partly responsible for this, and suggest that if this phase exists in QCD, then finding it in Monte-Carlo simulations would require simulating on relatively fine lattices. In particular, the baryon mass in lattice units, m_B, should be considerably smaller than its strong-coupling limit of m_B~3.Comment: 33 pages, 8 figure

Improved lattice operators for non-relativistic fermions

In this work I apply a recently proposed improvement procedure, originally conceived to reduce finite lattice spacing effects in transfer matrices for dilute Fermi systems, to tuning operators for the calculation of observables. I construct, in particular, highly improved representations for the energy and the contact, as a first step in an improvement program for finite-temperature calculations. I illustrate the effects of improvement on those quantities with a ground-state lattice calculation at unitarity.Comment: 11 pages, 7 figures; replaced with published versio

Recursive Construction of Generator for Lagrangian Gauge Symmetries

We obtain, for a subclass of structure functions characterizing a first class Hamiltonian system, recursive relations from which the general form of the local symmetry transformations can be constructed in terms of the independent gauge parameters. We apply this to a non-trivial Hamiltonian system involving two primary constraints, as well as two secondary constraints of the Nambu-Goto type.Comment: 10 pages, Late

Etablierung der homöopathischen Mastitistherapie in einem biologisch-dynamisch wirtschaftenden Milcherzeugerbetrieb unter Berücksichtigung ökologischer, epidemiologischer und ökonomischer Gesichtspunkte.

6 Summary The dairy cow mastitis as a disease with an immense economic impact is widely spread in organic as well as in conventional farms. Due to the lack of alternatives to antibiotic treatment, most therapeutical measures are based on antibiotics even in organic farms and against common regulations. In contrary to these procedures the EU regulations (Council Regulation EC 1804/99)as well as the consumer’s anticipation demand the possibly lowest levels of residual charges of dairy products and environment. A two and a half year study in a bio-dyn dairy herd in Brandenburg (Germany) with 300 dairy cows suffering from udder health problems was conducted to evaluate if clinical mastitis in dairy cows is to control successfully with homeopathic remedies to minimize antibiotic treatment. To assess the efficacy of the homeopathic treatment the investigations are made using a double blind placebo controlled study design (RCCT). Using a predetermined treatment protocol and a certain diagnostic pattern to match right remedies in the sense of the homeopathic remedy pictures, the intention of the chosen treatment schedule was to provide a very transparent concept which can be used also by unexperienced veterinarians. For treatment of acute mastitis the following remedies were used: Phytolacca D6, Bryonia D6 , Echinacea D6 and Belladonna D6. Aconitum D6 was added in case of fever at the beginning of disease. Cases of chronical and subclinical mastitis were treated by Echinacea D6, Phytolacca D6 and Hepar sulfuris D8. In the first part of the study nearly all mastitis cases were treated only with homeopathics avoiding antibiotics strictly. The unsatisfying results in this part lead to a modification in the second part in which in case of certain infections (S.aureus, Sc.spp.) a limited use of antibiotics was admitted. Furthermore, selected udders with subclinical and chronical infections with these kind of bacteria were dried off antibiotically. Simultaneously the farmer was engaged to intensify the efforts to optimize preventive and environmental measures in the herd. In the second part of the study 126 cows (148 quarters) suffered from clinical mastitis (Verum: n=60; Placebo: n=66). The cure rates were nearly identical. In the whole population the clinical cure rate (CCR) immediately after treatment was 95%, 7 to 8 weeks after treatment 65%. The 107 clinically affected quarters which were infected by pathogenic bacteria showed a bacteriological cure rate (BCR) of 55% each and a complete bacterio-cytological cure rate (BCCR) of 35% and 40% after 4-5 weeks and 7-8 weeks after treatment, respectively. During the observation time of 8 weeks a total of 12 cows in each of the treatment groups produced a homologous recurrent infection. 6 cows in the verum group and 4 cows in the placebo group developed a new infection in one of the other quarters. The treatment results seems to be satisfying while the enhanced but still not optimized environmental conditions in the herd are possibly responsible for the high amount of new infections and recurrences. Looking at the results of the study at all, the use of antibiotics could be decreased by 75% due to the therapy management (in spite of the change of it because of unsatisfying results) in combination with preventive measures. Additionally the herd udder health could be increased. So the mean herd somatic cell count decreased by 75.000 somatic cells/ml to 165.000 somatic cells/ml. Furthermore, the milk yield increased by 250 kg to 6.500 kg/cow/year. The count of infections with S. aureus in the herd decreased dramatically. The decreasing input of antibiotics in mastitis therapy in the project farm lead to a decrease of 36.000 kg antibiotically loaded milk compared to a hypothetic conventional mastitis management. Furthermore, the omission of withdrawal times after homeopathic treatment resulted in a benefit of additional production milk of 25.000 kg. The antibiotics minimizing therapy concept of the second part of this investigation which could be evaluated under practice conditions can be recommended for other farms too if simultaneous herd prevention measures can be assured by the farm manager to ensure good preconditions for the convalescence of the cows. The cure rates after placebo are unexpected high. Due to these results it is profoundly debatable whether the strategies of conventional therapy of bovine mastitis are suitable to ensure herd udder health. It should be evaluated which part of the cure rate is amounted by self cure and which other factors have an effect on the healing. The nearly identical cure rates in both treatment groups do not allow the proof of homeopathic efficacy at all. Indeed, comparing the bacteriologically caused mastitis cases (107 quarters), there is a significantly higher cure rate in the verum group (p < 0.05)

Gauge Invariant Variational Approach with Fermions: the Schwinger Model

We extend the gauge invariant variational approach of Phys. Rev. D52 (1995) 3719, hep-th/9408081, to theories with fermions. As the simplest example we consider the massless Schwinger model in 1+1 dimensions. We show that in this solvable model the simple variational calculation gives exact results.Comment: 14 pages, 1 figur