Factorizations of Elements in Noncommutative Rings: A Survey

We survey results on factorizations of non zero-divisors into atoms (irreducible elements) in noncommutative rings. The point of view in this survey is motivated by the commutative theory of non-unique factorizations. Topics covered include unique factorization up to order and similarity, 2-firs, and modular LCM domains, as well as UFRs and UFDs in the sense of Chatters and Jordan and generalizations thereof. We recall arithmetical invariants for the study of non-unique factorizations, and give transfer results for arithmetical invariants in matrix rings, rings of triangular matrices, and classical maximal orders as well as classical hereditary orders in central simple algebras over global fields.Comment: 50 pages, comments welcom

Thermal and Optical Characterization of Undoped and Neodymium-Doped Y3ScAl4O12 Ceramics

Y3–3xNd3xSc1Al4O12 (x = 0, 0.01, and 0.02) ceramics were fabricated by sintering at high temperature under vacuum. Unit cell parameter refinement and chemical analysis have been performed. The morphological characterization shows micrograins with no visible defects. The thermal analysis of these ceramics is presented, by measuring the specific heat in the temperature range from 300 to 500 K. Their values at room temperature are in the range 0.81–0.90 J g1–K–1. The thermal conductivity has been determined by two methods: by the experimental measurement of the thermal diffusivity by the photopyroelectric method, and by spectroscopy, evaluating the thermal load. The thermal conductivities are in the range 9.7–6.5 W K–1 m–1 in the temperature interval from 300 to 500 K. The thermooptic coefficients were measured at 632 nm by the dark mode method using a prism coupler, and the obtained values are in the range 12.8–13.3 × 10–6 K–1. The nonlinear refractive index values at 795 nm have been evaluated to calibrate the nonlinear optical response of these materials.This work is supported by the Spanish Government under projects MAT2011-29255-C02-01-02, MAT2013-47395-C4-4-R, and the Catalan Government under project 2014SGR1358. It was also funded by the European Commission under the Seventh Framework Programme, project Cleanspace, FP7-SPACE-2010-1-GA No. 263044

An early diagnosis is not the same as a timely diagnosis of Parkinson's disease

referee-status: Indexed referee-response-35490: 10.5256/f1000research.15815.r35490, Matthew J. Farrer, Djavad Mowafhagian Centre for Brain, University of British Columbia, Vancouver, British Columbia, Canada, 18 Jul 2018, version 1, indexed referee-response-35489: 10.5256/f1000research.15815.r35489, Mayela Rodriguez-Violante, Movement Disorders Clinic, National Institute of Neurology and Neurosurgery, Mexico City, Mexico, 18 Jul 2018, version 1, indexed grant-information: This review was supported by grants from: Parkinson’s UK (G-1606), National Institute for Health Research University College Hospitals Biomedical Research Centre and Bart’s Charity (Preventative Neurology Grant). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. copyright-info: This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This review was supported by grants from: Parkinson’s UK (G-1606), National Institute for Health Research University College Hospitals Biomedical Research Centre and Bart’s Charity (Preventative Neurology Grant)

Cognitive performance in neurokinin 3 receptor knockout mice

RATIONALE: The neurokinin 3 (NK(3)) receptor is a novel target under investigation for improvement of the symptoms of schizophrenia due to its ability to modulate dopaminergic signaling. However, research on effects of NK(3) antagonism with animal models has been hindered because of species differences in the receptor between humans, rats, and mice. OBJECTIVES: The aim of the present study is to further knowledge on the role of NK(3) in cognitive functioning by testing the effect of knockout of the NK(3) receptor on tests of working memory, spatial memory, and operant responding. MATERIALS AND METHODS: NK(3) knockout mice generated on a C57Bl/6 background were tested in delayed matching to position (DMTP), spontaneous alternation, Morris water maze, and active avoidance tasks. RESULTS: NK(3) knockout mice showed better performance in the DMTP task, though not delay dependently, which points to an effect on operant performance but not on working memory. No differences were seen between the groups in spontaneous alternation, another indication that working memory is not affected in NK(3) knockouts. There was no impairment in knockout mice in Morris water maze training, and the mice also showed faster response latency in the active avoidance task during training. CONCLUSIONS: Collectively, these results support a role for the NK(3) receptor in performance of operant tasks and in spatial learning but not in working memory

Pharmacovigilance [Pharmacovigilance update].

The main pharmacovigilance updates in 2014 are reviewed. Ivabradine: increased risk of cardiovascular death and myocardial infarction in patients with symptomatic angina treated with high dosages. Clopidogrel: rare observations of acquired hemophilia. Orlistat: may reduce the absorption of HIV antiretrovirals. Ponatinib: increased risk of arteriopathy and thrombosis. Axitinib: significant risk of heart failure (class effect). Tocilizumab: possible causal relationship with the emergence or aggravation of psoriasis. Lithium: hypercalcemia and hyperparathyroidism commonly observed. Sildenalfil: suspected causal association with melanoma, so far not proven, Methylphenidate: rare observations of priapism. St John's wort (Hypericum): reduced effectiveness of hormonal contraceptives, including implants

Cognitive performance in neurokinin 3 receptor knockout mice.

RATIONALE: The neurokinin 3 (NK(3)) receptor is a novel target under investigation for improvement of the symptoms of schizophrenia due to its ability to modulate dopaminergic signaling. However, research on effects of NK(3) antagonism with animal models has been hindered because of species differences in the receptor between humans, rats, and mice. OBJECTIVES: The aim of the present study is to further knowledge on the role of NK(3) in cognitive functioning by testing the effect of knockout of the NK(3) receptor on tests of working memory, spatial memory, and operant responding. MATERIALS AND METHODS: NK(3) knockout mice generated on a C57Bl/6 background were tested in delayed matching to position (DMTP), spontaneous alternation, Morris water maze, and active avoidance tasks. RESULTS: NK(3) knockout mice showed better performance in the DMTP task, though not delay dependently, which points to an effect on operant performance but not on working memory. No differences were seen between the groups in spontaneous alternation, another indication that working memory is not affected in NK(3) knockouts. There was no impairment in knockout mice in Morris water maze training, and the mice also showed faster response latency in the active avoidance task during training. CONCLUSIONS: Collectively, these results support a role for the NK(3) receptor in performance of operant tasks and in spatial learning but not in working memory

Cognitive performance in neurokinin 3 receptor knockout mice.

RATIONALE: The neurokinin 3 (NK(3)) receptor is a novel target under investigation for improvement of the symptoms of schizophrenia due to its ability to modulate dopaminergic signaling. However, research on effects of NK(3) antagonism with animal models has been hindered because of species differences in the receptor between humans, rats, and mice. OBJECTIVES: The aim of the present study is to further knowledge on the role of NK(3) in cognitive functioning by testing the effect of knockout of the NK(3) receptor on tests of working memory, spatial memory, and operant responding. MATERIALS AND METHODS: NK(3) knockout mice generated on a C57Bl/6 background were tested in delayed matching to position (DMTP), spontaneous alternation, Morris water maze, and active avoidance tasks. RESULTS: NK(3) knockout mice showed better performance in the DMTP task, though not delay dependently, which points to an effect on operant performance but not on working memory. No differences were seen between the groups in spontaneous alternation, another indication that working memory is not affected in NK(3) knockouts. There was no impairment in knockout mice in Morris water maze training, and the mice also showed faster response latency in the active avoidance task during training. CONCLUSIONS: Collectively, these results support a role for the NK(3) receptor in performance of operant tasks and in spatial learning but not in working memory

Monitoring alpha‐synuclein oligomerization and aggregation using bimolecular fluorescence complementation assays: What you see is not always what you get

Bimolecular fluorescence complementation (BiFC) was introduced a decade ago as a method to monitor alpha-synuclein (alpha-syn) oligomerization in intact cells. Since then, several alpha-syn BiFC cellular assays and animal models have been developed based on the assumption that an increase in the fluorescent signal correlates with increased alpha-syn oligomerization or aggregation. Despite the increasing use of these assays and models in mechanistic studies, target validation and drug screening, there have been no reports that (1) validate the extent to which the BiFC fluorescent signal correlates with alpha-syn oligomerization at the biochemical level; (2) provide a structural characterization of the oligomers and aggregates formed by the BiFC. To address this knowledge gap, we first analysed the expression level and oligomerization properties of the individual constituents of alpha-syn-Venus, one of the most commonly used BiFC systems, in HEK-293 & SH-SY5Y cells from three different laboratories using multiple biochemical approaches and techniques. Next, we investigated the biochemical and aggregation properties of alpha-syn upon co-expression of both BiFC fragments. Our results show that (1) the C-terminal-Venus fused to alpha-syn (alpha-syn-Vc) is present in much lower abundance than its counterpart with N-terminal-Venus fused to alpha-syn (Vn-alpha-syn); (2) Vn-alpha-syn exhibits a high propensity to form oligomers and higher-order aggregates; and (3) the expression of either or both fragments does not result in the formation of alpha-syn fibrils or cellular inclusions. Furthermore, our results suggest that only a small fraction of Vn-alpha-syn is involved in the formation of the fluorescent BiFC complex and that some of the fluorescent signal may arise from the association or entrapment of alpha-syn-Vc in Vn-alpha-syn aggregates. The fact that the N-terminal fragment exists predominantly in an aggregated state also indicates that one must exercise caution when using this system to investigate alpha-syn oligomerization in cells or in vivo. Altogether, our results suggest that cellular and animal models of oligomerization, aggregation and cell-to-cell transmission based on the alpha-syn BiFC systems should be thoroughly characterized at the biochemical level to ensure that they reproduce the process of interest and measure what they are intended to measure