E6SSM vs MSSM gluino phenomenology

The E6SSM is a promising model based on the group E6, assumed to be broken at the GUT scale, leading to the group SU(3)\times SU(2)\times U(1)\times U(1)' at the TeV scale. It gives a solution to the MSSM {\mu}-problem without introducing massless axions, gauge anomalies or cosmological domain walls. The model contains three families of complete 27s of E6, giving a richer phenomenology than the MSSM. The E6SSM generically predicts gluino cascade decay chains which are about 2 steps longer than the MSSM's due to the presence of several light neutralino states. This implies less missing (and more visible) transverse momentum in collider experiments and kinematical distributions such as M_eff are different. Scans of parameter space and MC analysis suggest that current SUSY search strategies and exclusion limits have to be reconsidered.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 3 pages, 7 figure

The Nonexistence of Instrumental Variables

The method of instrumental variables (IV) and the generalized method of moments (GMM) has become a central technique in health economics as a method to help to disentangle the complex question of causality. However the application of these techniques require data on a sufficient number of instrumental variables which are both independent and relevant. We argue that in general such instruments cannot exist. This is a reason for the widespread finding of weak instruments.

The status of traditional Scottish animal breeds and plant varieties and the implications for biodiversity

The aim of this scoping study was to evaluate the effects on Scottish biodiversity of changes in the use of traditional breeds and varieties. The overall objectives were: a) The evaluation of the importance of genetic loss from the reduction in use of these breeds and varieties, for example, the loss of unusual characteristics that might have been of particular local use. b) An assessment of the impacts of reduction in the ability to conduct further breeding or research on rare and traditional varieties and breeds. c) Identification of the loss of certain farming techniques associated with particular varieties and breeds. d) An assessment of possible losses of biodiversity associated with reduction in the use of these breeds and varieties and the farming systems associated with them

Desynchronization of pathological low-frequency brain activity by the hypnotic drug zolpidem.

Reports of the beneficial effects of the hypnotic imidazopyridine, zolpidem, described in persistent vegetative state^1, 2^ have been replicated recently in brain-injured and cognitively impaired patients^3-7^. Previous single photon emission computed tomography (SPECT) studies have suggested that sub-sedative doses of zolpidem increased regional cerebral perfusion in affected areas^5, 8^, implying enhanced neuronal metabolic activity; which has led to speculation that zolpidem 'reawakens' functionally dormant cortex. However, a neuronal mechanism by which this hypnotic drug affords benefits to brain injured patients has yet to be demonstrated. Here, we report the action of sub-sedative doses of zolpidem on neuronal network oscillatory activity in human brain, measured using pharmaco-magnetoencephalography (pharmaco-MEG). Study participant JP suffered a stroke in 1996, causing major damage to the left hemisphere that impaired aspects of both motor and cognitive function. Pharmaco-MEG analyses revealed robust and persistent pathological theta (4-10Hz) and beta (15-30Hz) oscillations within the lesion penumbra and surrounding cortex. Administration of zolpidem (5mg) reduced the power of pathological theta and beta oscillations in all regions of the lesioned hemisphere. This desynchronizing effect correlated well with zolpidem uptake (occurring approximately 40 minutes after acute administration) and was coincident with marked improvements in cognitive and motor function. Control experiments revealed no effect of placebo, while a structurally unrelated hypnotic, zopiclone, administered at a comparable dose (3.5mg) elicited widespread increases in cortical oscillatory power in the beta (15-30Hz) band without functional improvement. These results suggest that in JP, specific motor and cognitive impairments are related to increased low-frequency oscillatory neuronal network activity. Zolpidem is unique amongst hypnotic drugs in its ability to desynchronize such pathological low-frequency activity, thereby restoring cognitive function

Designing antibiotic cycling strategies by determining and understanding local adaptive landscapes

The evolution of antibiotic resistance among bacteria threatens our continued ability to treat infectious diseases. The need for sustainable strategies to cure bacterial infections has never been greater. So far, all attempts to restore susceptibility after resistance has arisen have been unsuccessful, including restrictions on prescribing [1] and antibiotic cycling [2,3]. Part of the problem may be that those efforts have implemented different classes of unrelated antibiotics, and relied on removal of resistance by random loss of resistance genes from bacterial populations (drift). Here, we show that alternating structurally similar antibiotics can restore susceptibility to antibiotics after resistance has evolved. We found that the resistance phenotypes conferred by variant alleles of the resistance gene encoding the TEM {\beta}-lactamase (blaTEM) varied greatly among 15 different {\beta}-lactam antibiotics. We captured those differences by characterizing complete adaptive landscapes for the resistance alleles blaTEM-50 and blaTEM-85, each of which differs from its ancestor blaTEM-1 by four mutations. We identified pathways through those landscapes where selection for increased resistance moved in a repeating cycle among a limited set of alleles as antibiotics were alternated. Our results showed that susceptibility to antibiotics can be sustainably renewed by cycling structurally similar antibiotics. We anticipate that these results may provide a conceptual framework for managing antibiotic resistance. This approach may also guide sustainable cycling of the drugs used to treat malaria and HIV

NGC 4340: Double Bar + Fossil Nuclear Ring

NGC 4340 is a double-barred SB0 galaxy in the Virgo cluster (Wozniak et al. 1995). Here, we present evidence that this galaxy also posseses a luminous stellar nuclear ring of relatively old stars with little or no gas. The ring lies just outside the inner bar, at the probable inner inner Lindblad resonance (IILR) of the outer bar. Careful inspection of the isophotes and unsharp masks shows that the two bars are slightly misaligned, which suggests they may be independently rotating.Comment: 1 Page, 1 figure, kluwer.cls needed to complile (included in tar file) Poster presented at the Granada Euroconference (May, 2000): The Evolution of Galaxies. I- Observational clue

Is the relationship between prices and exchange rates homogeneous?

Empirical tests of purchasing power parity (PPP) are implicitly based on the conditions of symmetry and proportionality of the price coefficients. We investigate a separate condition, which we term homogeneity. Specifically, while there may be factors that drive a wedge between prices and exchange rates, when these factors are held constant we would expect a change in exchange rates to be associated with a proportional, or homogeneous, change in prices. To test for the existence of homogeneity in prices, we conduct two experiments. First, we apply a time-varying-coefficient procedure to nine euro-area countries as well as the euro area as a whole during the (monthly) sample period, 1999:M1 to 2011:M3. Second we apply the same procedure to the same group of countries, plus Canada, Japan and Mexico, over the longer period, 1957:M4 to 2011:M3. We find that averages of the price coefficients, corrected for specification biases, are uniformly homogeneous in the long run, providing strong support for PPP