Vitamin D (VitD) deficiency can exacerbate AD progression and may cause changes in brain metabolite levels that can be detected by magnetic resonance spectroscopy (MRS). The purpose of this study was ...to determine whether chronic VitD deficiency in an AD mouse model caused persistent metabolite levels changes in the hippocampus associated with memory performance. Six-month-old APPSwe/PS1ΔE9 (APP/PS1) mice (N = 14 mice/group) were fed either a VitD deficient (VitD-) diet or a control diet. Metabolite level changes in the hippocampus were evaluated by 1H MRS using a 9.4 T MRI. Ventricle volume was assessed by imaging and spatial memory was evaluated using the Barnes maze. All measurements were made at 6, 9, 12, and 15 months of age. At 15 months of age, amyloid plaque load and astrocyte number were evaluated histologically (N = 4 mice/group). Levels of N-acetyl aspartate and creatine were lower in VitD- mice compared to control diet mice at 12 months of age. VitD deficiency did not change ventricle volume. Lactate levels increased over time in VitD- mice and increases from 12 to 15 months were negatively correlated with changes in primary latency to the target hole in the Barns Maze. VitD- mice showed improved spatial memory performance compared to control diet mice. VitD- mice also had more astrocytes in the cortex and hippocampus at 15 months than control diet mice. This study suggests that severe VitD deficiency in APP/PS1 mice may lead to compensatory changes in metabolite and astrocyte levels that contribute to improved performance on spatial memory tasks.
Julian Barnes Childs, Peter
2013., 20130719, 2011, 2013-07-19
eBook
Julian Barnes is a comprehensive introductory overview of the novels that situates his work in terms of fabulation and memory, irony and comedy. It pursues a broadly chronological line through ...Barnes's literary career, but along the way it also shows how certain key thematic preoccupations and obsessions seem to tie Barnes's oeuvre together (love, death, art, history, truth, and memory). Chapters provide detailed readings of each major publication in turn while treating the major concerns of Barnes’s fiction, including art, authorship, history, love and religion. The book is very lucidly written, and it is also satisfyingly comprehensive - alongside the 'canonical' Barnes texts, it includes brief but illuminating discussion of the crime fiction that Barnes has published under the pseudonym Dan Kavanagh. This detailed study of the fictions of Julian Barnes from Metroland to Arthur & George also benefits from archival research into his unpublished materials. The book will be a useful resource for scholars, postgraduates and undergraduates working in the field of contemporary literature.
We introduce a 1-cocycle Z of the group G=PGL2(Q) with values in a module D of distributions (in the sense of Stevens and Hu-Solomon). This cocycle is essentially constructed from the Barnes' double ...zeta function and it has the advantage of defining a family of maps that depend meromorphically on the usual parameter s∈C. In particular, this permits the extension of the cocycle property to any Taylor coefficient of such zeta function at s=0. Furthermore, we show that the class of Z in the first cohomology group H1(G,D) is nonzero, and we use basic facts about the arithmetic of real quadratic fields to prove the vanishing of H0(G,D), the group of G-invariant elements in D.
The immunologic modulation of glutamate (Glu) neurotransmission is a topic of great interest. Neuroinflammation is an intrinsic component of neurodegenerative diseases, as well as a factor ...responsible for cognitive and behavioral changes. Cyclooxygenase-2 (COX-2) expression in the brain was shown to be associated with inflammation. COX-2 is also widely expressed in the brain including neurons and glia and participates in fundamental brain functions, e.g. in synaptic plasticity or memory consolidation. Furthermore, COX-2/Glu interplay has been reported, while metabotropic glutamate receptors (mGluRs) are known to contribute to plastic changes and to behavior. The primary goal of this study was to explain the behavioral consequences of the modulation of the glutamatergic pathway via the interaction of the mGlu5 receptor and COX-2, utilizing a panel of behavioral tests.
To determine whether the glutamatergic pathway and COX-2 are involved in modulating the behavior of mice, C57B1/6 J and CD-1 male mice were injected daily with MTEP an mGluR5 antagonist, or a combination of MTEP and NS398 (COX-2 inhibitor) for 7 and 14 days. The following behavioral tests were used to screen for possible effects of the drug administration and interaction of the 2 compounds: the modified Barnes maze (MBM), stress-induced hyperthermia (SIH), Porsolt test (PT), tail suspension test (TST), modified rotarod (MR), and social interaction (SI) test.
A time-dependent influence on spatial learning was found after the co-administration of MTEP and NS398. Furthermore, NS398 injected chronically amplified the antidepressant-like effects of MTEP in the PT and TST, and influenced the tolerance development observed after MTEP treatment in the SIH test.
Combined use of cannabis and alcohol is common in adolescents. However, the extent to which such polydrug exposure affects the brain and behaviors remains under-investigated in preclinical studies. ...This study tested the hypothesis that combined exposure of Δ-9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, and alcohol will have additive effects on cognitive impairments and altered endocannabinoid levels in the hippocampus and frontal cortex. Male Long Evans rats were provided with daily access to cookies laced with oil or dronabinol, a synthetic THC, during adolescence. Three days after discontinuation of edible THC, the effect of orally administered 3 g/kg alcohol on Barnes maze performance was assessed. The results showed that experience with edible THC facilitated the occurrence of increased moving speed on the maze induced by repeated alcohol administration. However, contrasting to the hypothesis, the combined THC and alcohol exposure did not lead to additive deficits in learning and memory on the Barnes maze. While little effect on endocannabinoid levels was observed in the hippocampus, acute abstinence from alcohol significantly reduced endocannabinoid levels in the frontal cortex. In particular, reduction of N-oleoyl ethanolamine (OEA) and N-stearoyl ethanolamine (SEA) were robust and had an interactive effect with discontinuation from edible THC. These findings add to the scarce literature on THC and alcohol associated changes in endocannabinoid levels and provide insights to future investigations on the roles of OEA and SEA on physiology and behaviors following THC and alcohol co-exposure during adolescence.
•Adolescent rats readily consumed cookies laced with dronabinol (THC).•Edible THC increased appetite with a compensatory suppression of food intake.•Experience with edible THC facilitated alcohol-induced increase in moving speed.•Oral alcohol (3 g/kg) increased errors made to locate escape on a Barnes maze.•Abstinence from THC and alcohol blunted OEA and SEA levels in the frontal cortex.
«Fantasy is like jam: you have to spread it on a solid slice of bread»: this observation by Italo Calvino is perfectly in line with all those narratives that are based on the construction of ...imaginary worlds, nonexistent or invisible cities, landscape dreams, and simulacra. In this regard, a short story by the Australian writer Peter Carey, American Dreams (1974), and Julian Barnes’s novel England, England, (1998) seem extremely interesting. In both texts, it is a question of being able to invent lies capable of convincing readers, of substituting real places with false but plausible and narratively credible spaces. In the first case, the story showcases a point of conjunction between postmodern and postcolonial views thanks to Carey’s way of dealing with the theme of simulation. The text presents two dimensions of simulation: a postmodern field of simulacra in which all meaning implodes and about which nothing can be done, and a postcolonial field of representation in which simulation and performativity become the strategies of a cultural struggle. In the second case, the protagonist's theme park aims to encompass all the life-size tourist and cultural attractions across England, appropriately selected through a survey. This is not a miniature England, therefore, but an "England, England", a replica truer than the truth to the point of replacing the original, which is doomed to an irreversible decline, in a perfect depiction of the supermodernity theorised by Augè. Both the theme park and the model town reproduce the ideal space of those who, too accustomed to images, no longer know how to appreciate reality or, differently put, the postmodern world, reduced to a succession of empty images, entirely spectacularised. It is a world where things happen as in a dream. We could call this situation the Truman Show effect, referring to the famous 1998 film by Australian director Peter Weir.
In this paper, we establish new integral representations for the remainder term of the known asymptotic expansion of the logarithm of the Barnes G-function. Using these representations, we obtain ...explicit and numerically computable error bounds for the asymptotic series, which are much simpler than those obtained earlier by other authors. We find that along the imaginary axis, suddenly infinitely many exponentially small terms appear in the asymptotic expansion of the Barnes G-function. Employing one of our representations for the remainder term, we derive an exponentially improved asymptotic expansion for the logarithm of the Barnes G-function, which shows that the appearance of these exponentially small terms is in fact smooth, thereby proving the Berry transition property of the asymptotic series of the G-function.
We have developed a new method for the efficient numerical simulation of colloidal suspensions. This method is designed and especially well-suited for parallel code execution, but it can also be ...applied to single-core programs. It combines the Stokesian Dynamics method with a variant of the widely used Barnes–Hut algorithm in order to reduce computational costs. This combination and the inherent parallelization of the method make simulations of large numbers of particles within days possible. The level of accuracy can be determined by the user and is limited by the truncation of the used multipole expansion. Compared to the original Stokesian Dynamics method the complexity can be reduced from O(N2) to linear complexity for dilute suspensions of strongly clustered particles, N being the number of particles. In case of non-clustered particles in a dense suspension, the complexity depends on the particle configuration and is between O(N) and O(Pnp,max2), where P is the number of used processes and np,max=⌈N/P⌉, respectively.
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