The role of working memory for cognitive control in anorexia nervosa versus substance use disorder

Prefrontal cortex executive functions, such as working memory (WM) interact with limbic processes to foster impulse control. Such an interaction is referred to in a growing body of publications by terms such as cognitive control, cognitive inhibition, affect regulation, self-regulation, top-down control, and cognitive-emotion interaction. The rising trend of research into cognitive control of impulsivity, using various related terms reflects the importance of research into impulse control, as failure to employ cognitions optimally may eventually result in mental disorder. Against this background, we take a novel approach using an impulse control spectrum model - where anorexia nervosa (AN) and substance use disorder (SUD) are at opposite extremes - to examine the role of WM for cognitive control. With this aim, we first summarize WM processes in the healthy brain in order to frame a systematic review of the neuropsychological, neural and genetic findings of AN and SUD. In our systematic review of WM/cognitive control, we found n = 15 studies of AN with a total of n = 582 AN and n = 365 HC participants; and n = 93 studies of SUD with n = 9106 SUD and n = 3028 HC participants. In particular, we consider how WM load/capacity may support the neural process of excessive epistemic foraging (cognitive sampling of the environment to test predictions about the world) in AN that reduces distraction from salient stimuli. We also consider the link between WM and cognitive control in people with SUD who are prone to 'jumping to conclusions' and reduced epistemic foraging. Finally, in light of our review, we consider WM training as a novel research tool and an adjunct to enhance treatment that improves cognitive control of impulsivity. © 2017 Brooks, Funk, Young and Schiöth

On the Renormalizability of Horava-Lifshitz-type Gravities

In this note, we discuss the renormalizability of Horava-Lifshitz-type gravity theories. Using the fact that Horava-Lifshitz gravity is very closely related to the stochastic quantization of topologically massive gravity, we show that the renormalizability of HL gravity only depends on the renormalizability of topologically massive gravity. This is a consequence of the BRST and time-reversal symmetries pertinent to theories satisfying the detailed balance condition.Comment: 13 pages, references added, typos fixe

ALMA Observations of the Physical and Chemical Conditions in Centaurus A

Centaurus A, with its gas-rich elliptical host galaxy, NGC 5128, is the nearest radio galaxy at a distance of 3.8 Mpc. Its proximity allows us to study the interaction between an active galactic nucleus, radio jets, and molecular gas in great detail. We present ALMA observations of low J transitions of three CO isotopologues, HCN, HCO$^{+}$, HNC, CN, and CCH toward the inner projected 500 pc of NGC 5128. Our observations resolve physical sizes down to 40 pc. By observing multiple chemical probes, we determine the physical and chemical conditions of the nuclear interstellar medium of NGC 5128. This region contains molecular arms associated with the dust lanes and a circumnuclear disk (CND) interior to the molecular arms. The CND is approximately 400 pc by 200 pc and appears to be chemically distinct from the molecular arms. It is dominated by dense gas tracers while the molecular arms are dominated by $^{12}$CO and its rare isotopologues. The CND has a higher temperature, elevated CN/HCN and HCN/HNC intensity ratios, and much weaker $^{13}$CO and C$^{18}$O emission than the molecular arms. This suggests an influence from the AGN on the CND molecular gas. There is also absorption against the AGN with a low velocity complex near the systemic velocity and a high velocity complex shifted by about 60 km s$^{-1}$. We find similar chemical properties between the CND in emission and both the low and high velocity absorption complexes implying that both likely originate from the CND. If the HV complex does originate in the CND, then that gas would correspond to gas falling toward the supermassive black hole

Dietary topoisomerase II-poisons

DNA topoisomerases are nuclear enzymes inducing transient breaks in the DNA allowing DNA strands or double helices to pass through each other. The clinically used DNA topoisomerase II-poison etoposide is known to induce DNA double strand breaks leading to chromosomal aberrations and leukemias. Recently, some alarming studies have been published, suggesting that maternal exposure to low doses of dietary topoisomerase II-poisons, including bioflavonoids such as genistein or quercetin, may contribute to the development of infant leukemia: approximately 80% of infants with acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) have chromosome translocations involving the MLL (mixed lineage leukemia) gene. It has been shown that antineoplastic chemotherapy with the leukemogenic topoisomerase II-poison etoposide induced identical chromosomal aberrations involving the MLL gene compared to children with infant leukemia. Interestingly, the MLL cleavage sites induced by etoposide colocalized with the cleavage sites observed in infant leukemia. In addition, an almost 10-fold higher risk of infant AML has been reported for mothers consuming relatively high levels of topoisomerase II-poison containing foods. These observations are relevant, since many foods contain topoisomerase II-poisons, predominantly soy and soy products, but also coffee, wine, tea, cocao, as well as some fruits and vegetables. Further studies on the role of dietary topoisomerase II-poisons are urgently required. If the causal relationship between dietary exposure to topoisomerase II-poisons and infant leukemia will be confirmed, care should be taken to reduce exposure to critical foods during pregnancy

Classical Integrability of the Squashed Three-sphere, Warped AdS3 and Schroedinger Spacetime via T-Duality

We discuss the integrability of 2d non-linear sigma models with target space being the squashed three-sphere, warped anti-de Sitter space and the Schroedinger spacetime. These models can be obtained via T-duality from integrable models. We construct an infinite family of non-local conserved charges from the T-dual Lax currents, enhancing the symmetry of warped anti-de Sitter space and the Schroedinger spacetime to sl2(R)+sl2(R).Comment: 29 Pages, 3 appendices. Minor changes: added references, footnot