Effect of voluntary running on adult hippocampal neurogenesis in cholinergic lesioned mice

<p>Abstract</p> <p>Background</p> <p>Cholinergic neuronal dysfunction of the basal forebrain is observed in patients with Alzheimer's disease and dementia, and has been linked to decreased neurogenesis in the hippocampus, a region involved in learning and memory. Running is a robust inducer of adult hippocampal neurogenesis. This study aims to address the effect of running on hippocampal neurogenesis in lesioned mice, where septohippocampal cholinergic neurones have been selectively eliminated in the medial septum and diagonal band of Broca of the basal forebrain by infusion of mu-p75-saporin immunotoxin.</p> <p>Results</p> <p>Running increased the number of newborn cells in the dentate gyrus of the hippocampus in cholinergic denervated mice compared to non-lesioned mice 24 hours after injection of bromodeoxyuridine (BrdU). Although similar levels of surviving cells were present in cholinergic depleted animals and their respective controls four weeks after injection of BrdU, the majority of progenitors that proliferate in response to the initial period of running were not able to survive beyond one month without cholinergic input. Despite this, the running-induced increase in the number of surviving neurones was not affected by cholinergic depletion.</p> <p>Conclusion</p> <p>The lesion paradigm used here models aspects of the cholinergic deficits associated with Alzheimer's Disease and aging. We showed that running still increased the number of newborn cells in the adult hippocampal dentate gyrus in this model of neurodegenerative disease.</p

Novel Polynomial Basis and Its Application to Reed-Solomon Erasure Codes

In this paper, we present a new basis of polynomial over finite fields of characteristic two and then apply it to the encoding/decoding of Reed-Solomon erasure codes. The proposed polynomial basis allows that $h$-point polynomial evaluation can be computed in $O(h\log_2(h))$ finite field operations with small leading constant. As compared with the canonical polynomial basis, the proposed basis improves the arithmetic complexity of addition, multiplication, and the determination of polynomial degree from $O(h\log_2(h)\log_2\log_2(h))$ to $O(h\log_2(h))$. Based on this basis, we then develop the encoding and erasure decoding algorithms for the $(n=2^r,k)$ Reed-Solomon codes. Thanks to the efficiency of transform based on the polynomial basis, the encoding can be completed in $O(n\log_2(k))$ finite field operations, and the erasure decoding in $O(n\log_2(n))$ finite field operations. To the best of our knowledge, this is the first approach supporting Reed-Solomon erasure codes over characteristic-2 finite fields while achieving a complexity of $O(n\log_2(n))$, in both additive and multiplicative complexities. As the complexity leading factor is small, the algorithms are advantageous in practical applications

Observational Evidence for the Effect of Amplification Bias in Gravitational Microlensing Experiments

Recently Alard\markcite{alard1996} proposed to detect the shift of a star's image centroid, $\delta x$, as a method to identify the lensed source among blended stars. Goldberg & Wo\'zniak\markcite{goldberg1997} actually applied this method to the OGLE-1 database and found that 7 out of 15 events showed significant centroid shifts of $\delta x \gtrsim 0.2$ arcsec. The amount of centroid shift has been estimated theoretically by Goldberg.\markcite{goldberg1997} However, he treated the problem in general and did not apply it to a particular survey or field, and thus based his estimates on simple toy model luminosity functions (i.e., power laws). In this paper, we construct the expected distribution of $\delta x$ for Galactic bulge events by using the precise stellar LF observed by Holtzman et al.\markcite{holtzman1998} using HST. Their LF is complete up to $M_I\sim 9.0$ ($M_V\sim 12$), corresponding to faint M-type stars. In our analysis we find that regular blending cannot produce a large fraction of events with measurable centroid shifts. By contrast, a significant fraction of events would have measurable centroid shifts if they are affected by amplification-bias blending. Therefore, Goldberg & Wo\'zniak's measurements of large centroid shifts for a large fraction of microlensing events confirms the prediction of Han and Alard that a large fraction of Galactic bulge events are affected by amplification-bias blending.Comment: total 15 pages, including 6 figures, and no Table, submitted to ApJ on Apr 26 1998, email [email protected]

Modulation of paclitaxel resistance by annexin IV in human cancer cell lines

A recurring problem with cancer therapies is the development of drug resistance. While investigating the protein profile of cells resistant to a novel antimitotic compound (A204197), we discovered an increase in annexin IV expression. When we examined the annexin IV protein expression level in a paclitaxel-resistant cell line (H460/T800), we found that annexin IV was also overexpressed. Interestingly a closely related protein, annexin II, was not overexpressed in H460/T800 cells. Immunostaining with either annexin II or IV antibody revealed that annexin IV was primarily located in the nucleus of paclitaxel-resistant H460/T800 cells. Short-term treatment of H460 cells with 10 nMpaclitaxel for up to 4 days resulted in induction of annexin IV, but not annexin II expression. In addition, there was an increase in annexin IV staining in the nucleus starting at day 1. Furthermore, cells pretreated with 10 nMpaclitaxel for 4 days resulted in cells becoming ~fivefold more resistant to paclitaxel. Transfection of annexin IV cDNA into 293T cells revealed that there was a threefold increase in paclitaxel resistance. Thus our results indicate that annexin IV plays a role in paclitaxel resistance in this cell line and it is among one of the earliest proteins that is induced in cells in response to cytotoxic stress such as antimitotic drug treatment. © 2000 Cancer Research Campaig

Decoupling H_2(g) and O_2(g) Production in Water Splitting by a Solar-Driven V^(3+/2)+(aq,H_2SO_4)|KOH(aq) Cell

A solar-driven V^(3+/2+)(aq,H_2SO_4)|KOH(aq) cell, consisting of a carbon-cloth cathode in 2.0 M H_2SO_4(aq) with 0.36 M V_2(SO_4)_3 (pH −0.16), a Ni mesh anode in 2.5 M KOH(aq) (pH 14.21) for the oxygen-evolution reaction (OER), and a bipolar membrane that sustained the pH differentials between the catholyte and anolyte, enabled water splitting with spatial and temporal decoupling of the hydrogen evolution reaction (HER) from the OER and produced H_2(g) locally under pressure upon demand. Over a range of potentials and charging depths, V^(3+) was selectively reduced with >99.8% faradic efficiency. The V^(2+) species produced in the catholyte was then passed subsequently on demand over a MoCx-based HER catalyst to produce H_2(g) and regenerate V^(3+) for subsequent reduction. Under a base hydrogen pressure of 1, 10, and 100 atm, the discharge efficiency of the V^(3+) to hydrogen was 83%, 65.2%, and 59.8%, respectively. In conjunction with a solar tracker and a photovoltaic device, the V^(3+/2+)(aq,H_2SO_4)|KOH(aq) cell was charged outdoors under sunlight and discharged at night with a daily averaged diurnal solar-to-hydrogen (STH) energy conversion efficiency of 3.7% and a STH conversion efficiency of 5.8% during daylight operation

A Study of the Effect of Anger on Immoral Judgment of Internet Privacy Invasion

With the emergence of Web 2.0, people are able to share their thoughts and photos with their friends and strangers. Yet, they also risk invasion of their privacy. Information privacy has therefore become an important issue in the information age. In this research, we focus on the influence of anger on immoral judgment of privacy invasion in cyberspace. Specifically, two scenarios, nonviolent and violent-depiction, are designed to investigate the influence of anger on immoral decision making. Our results revealed that the level of anger will increase immoral judgment in nonviolent and violent depiction scenarios, respectively. And the level of anger in violent-depiction scenario is higher than in nonviolent-depiction scenario. The research findings show that college students easily make an immoral judgment in violent situations. In violent depiction scenario, however, high moral obligation group can enhance the effect of ethical self-efficacy for moral judgment