The Effects of Lipopolysaccharide-induced Neuroinflammation on Learning and Forgetting in Juvenile Rats

The inability to remember events experienced very early in life is referred to as Infantile Amnesia (IA) and has been observed in both humans and animals. Over the years interest in the phenomenon waned, but has recently increased with the discovery of new neurobiological methods to study brain function (e.g., Callaghan, Li & Richardson, 2014). The neurobiological mechanism behind IA has yet to be determined, but several innovative theories have been developed with these new research methods. The neurogenesis hypothesis theorizes that increased neurogenesis during early development disrupts previously established memories. The hippocampus, an area that mediates both the memory of a fearful experience and the memory of a context is an area that undergoes neurogenesis lifelong but especially early in development. The increased amount of neurogenesis in the hippocampus early in life may disrupt the memory of fearful contexts in young rats. The current study examined the effect of lipopolysaccharide (LPS), on the memory for a context paired with foot shock in developing rats using the context preexposure facilitation effect (CPFE) procedure. LPS is an endotoxin that activates the immune system and reduces neurogenesis in the process. Rats exposed to a context at 24 days of age and shocked, after a 22 day retention interval showed less freezing the next day than those tested after a 2 day retention interval, suggesting they forgot the context cues over time, a trait suggestive of IA. Rats injected with LPS showed significantly lower rates of freezing compared to saline-treated rats at both retention intervals, thus showing overall poorer performance rather than reduced forgetting at the longer retention interval. The results from the current study fail to support the neurogenesis hypothesis. Implications of using LPS for a test of the neurogenesis hypothesis are discussed

The Effects of Lipopolysaccharide-induced Neuroinflammation on Learning and Forgetting in Juvenile Rats

The inability to remember events experienced very early in life is referred to as Infantile Amnesia (IA) and has been observed in both humans and animals. Over the years interest in the phenomenon waned, but has recently increased with the discovery of new neurobiological methods to study brain function (e.g., Callaghan, Li & Richardson, 2014). The neurobiological mechanism behind IA has yet to be determined, but several innovative theories have been developed with these new research methods. The neurogenesis hypothesis theorizes that increased neurogenesis during early development disrupts previously established memories. The hippocampus, an area that mediates both the memory of a fearful experience and the memory of a context is an area that undergoes neurogenesis lifelong but especially early in development. The increased amount of neurogenesis in the hippocampus early in life may disrupt the memory of fearful contexts in young rats. The current study examined the effect of lipopolysaccharide (LPS), on the memory for a context paired with foot shock in developing rats using the context preexposure facilitation effect (CPFE) procedure. LPS is an endotoxin that activates the immune system and reduces neurogenesis in the process. Rats exposed to a context at 24 days of age and shocked, after a 22 day retention interval showed less freezing the next day than those tested after a 2 day retention interval, suggesting they forgot the context cues over time, a trait suggestive of IA. Rats injected with LPS showed significantly lower rates of freezing compared to saline-treated rats at both retention intervals, thus showing overall poorer performance rather than reduced forgetting at the longer retention interval. The results from the current study fail to support the neurogenesis hypothesis. Implications of using LPS for a test of the neurogenesis hypothesis are discussed

Harassment, stalking, threats and attacks targeting New Zealand politicians: a mental health issue

The harassment of politicians has significant psychosocial costs for both the victim and the perpetrator and represents an opportunity for mental health intervention. Abstract Objective: Due to the nature of their work, politicians are at greater risk of stalking, harassment and attack than the general population. The small, but significantly elevated risk of violence to politicians is predominantly due not to organised terrorism or politically motivated extremists but to fixated individuals with untreated serious mental disorders, usually psychosis. Our objective was to ascertain the frequency, nature and effects of unwanted harassment of politicians in New Zealand and the possible role of mental illness in this harassment. Methods: New Zealand Members of Parliament were surveyed, with an 84% response rate (n = 102). Quantitative and qualitative data were collected on Parliamentarians’ experiences of harassment and stalking. Results: Eighty-seven percent of politicians reported unwanted harassment ranging from disturbing communications to physical violence, with most experiencing harassment in multiple modalities and on multiple occasions. Cyberstalking and other forms of online harassment were common, and politicians felt they (and their families) had become more exposed as a result of the Internet. Half of MPs had been personally approached by their harassers, 48% had been directly threatened and 15% had been attacked. Some of these incidents were serious, involving weapons such as guns, Molotov cocktails and blunt instruments. One in three politicians had been targeted at their homes. Respondents believed the majority of those responsible for the harassment exhibited signs of mental illness. Conclusion: The harassment of politicians in New Zealand is common and concerning. Many of those responsible were thought to be mentally ill by their victims. This harassment has significant psychosocial costs for both the victim and the perpetrator and represents an opportunity for mental health intervention

The Star Formation Law in Nearby Galaxies on Sub-Kpc Scales

(Abridged) We present a comprehensive analysis of the relationship between star formation rate surface density (SFR SD) and gas surface density (gas SD) at sub-kpc resolution in a sample of 18 nearby galaxies. We use high resolution HI data from THINGS, CO data from HERACLES and BIMA SONG, 24 micron data from the Spitzer Space Telescope, and UV data from GALEX. We target 7 spiral galaxies and 11 late-type/dwarf galaxies and investigate how the star formation law differs between the H2-dominated centers of spiral galaxies, their HI-dominated outskirts and the HI-rich late-type/dwarf galaxies. We find that a Schmidt-type power law with index N=1.0+-0.2 relates the SFR SD and the H2 SD across our sample of spiral galaxies, i.e., that H2 forms stars at a constant efficiency in spirals. The average molecular gas depletion time is ~2*10^9 yrs. We interpret the linear relation and constant depletion time as evidence that stars are forming in GMCs with approximately uniform properties and that the H2 SD may be more a measure of the filling fraction of giant molecular clouds than changing conditions in the molecular gas. The relationship between total gas SD and SFR SD varies dramatically among and within spiral galaxies. Most galaxies show little or no correlation between the HI SD and the SFR SD. As a result, the star formation efficiency (SFE = SFR SD / gas SD) varies strongly across our sample and within individual galaxies. We show that in spirals the SFE is a clear function of radius, while the dwarf galaxies in our sample display SFEs similar to those found in the outer optical disks of the spirals. Another general feature of our sample is a sharp saturation of the HI SD at ~9 M_sol/pc^2 in both the spiral and dwarf galaxies.Comment: Accepted for publication in the AJ special THINGS issue. For a high-resolution version visit: http://www.mpia.de/THINGS/Publications.htm

Ectromelia virus encodes an anti-apoptotic protein that regulates cell death

AbstractApoptosis serves as a powerful defense against damaged or pathogen-infected cells. Since apoptosis is an effective defense against viral infection, many viruses including poxviruses, encode proteins to prevent or delay apoptosis. Here we show that ectromelia virus, the causative agent of mousepox encodes an anti-apoptotic protein EVM025. Here we demonstrate that expression of functional EVM025 is crucial to prevent apoptosis triggered by virus infection and staurosporine. We demonstrate that the expression of EVM025 prevents the conformational activation of the pro-apoptotic proteins Bak and Bax, allowing the maintenance of mitochondrial membrane integrity upon infection with ECTV. Additionally, EVM025 interacted with intracellular Bak. We were able to demonstrate that EVM025 ability to inhibit Bax activation is a function of its ability to inhibit the activity of an upstream BH3 only protein Bim. Collectively, our data indicates that EVM025 inhibits apoptosis by sequestering Bak and inhibiting the activity of Bak and Bax

MILP-based local search procedures for minimizing total tardiness in the No-idle Permutation Flowshop Problem

We consider the No-idle Permutation Flowshop Scheduling Problem (NPFSP) with a total tardiness criterion. We present two Mixed Integer Linear Programming (MILP) formulations based on positional and precedence variables, respectively. We study six local search procedures that explore two different neighborhoods by exploiting the MILP formulations. Our computational experiments show that two of the proposed procedures strongly outperform the state-of-the-art metaheuristic. We update 63% of the best known solutions of the instances in Taillards’ benchmark, and 77% if we exclude those instances for which we proved that the previous best known solutions are optimal

Energy Efficient Manufacturing Scheduling: A Systematic Literature Review

The social context in relation to energy policies, energy supply, and sustainability concerns as well as advances in more energy-efficient technologies is driving a need for a change in the manufacturing sector. The main purpose of this work is to provide a research framework for energy-efficient scheduling (EES) which is a very active research area with more than 500 papers published in the last 10 years. The reason for this interest is mostly due to the economic and environmental impact of considering energy in production scheduling. In this paper, we present a systematic literature review of recent papers in this area, provide a classification of the problems studied, and present an overview of the main aspects and methodologies considered as well as open research challenges

Studying the universality of field induced tunnel ionization times via high-order harmonic spectroscopy

High-harmonics generation spectroscopy is a promising tool for resolving electron dynamics and structure in atomic and molecular systems. This scheme, commonly described by the strong field approximation, requires a deep insight into the basic mechanism that leads to the harmonics generation. Recently, we have demonstrated the ability to resolve the first stage of the process -- field induced tunnel ionization -- by adding a weak perturbation to the strong fundamental field. Here we generalize this approach and show that the assumptions behind the strong field approximation are valid over a wide range of tunnel ionization conditions. Performing a systematic study -- modifying the fundamental wavelength, intensity and atomic system -- we observed a good agreement with quantum path analysis over a range of Keldysh parameters. The generality of this scheme opens new perspectives in high harmonics spectroscopy, holding the potential of probing large, complex molecular systems.Comment: 11 pages, 5 figure