Septal and Hippocampal Glutamate Receptors Modulate the Output of Acetylcholine in Hippocampus: A Microdialysis Study

Abstract: In the present study, glutamate receptor agonists and antagonists were administered by retrograde microdialysis into either the medial septum/vertical limb of the diagonal band (MS/vDB), or hippocampus, and the output of acetylcholine (ACh) was measured in the hippocampus by using intracerebral microdialysis. Perfusion with N -methyl- d -aspartate (NMDA) and ( S )-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) in the MS/vDB caused an increase in ACh output in the hippocampus. This increase was completely blocked by coadministration of their respective antagonists d (−)-2-amino-5-phosphonopentanoic acid ( d -AP5) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Perfusion in the MS/vDB with kainic acid also caused an increase in ACh output, but coadministration of CNQX attenuated the increase only partially. Perfusion with d -AP5 or CNQX alone in the septal probe did not affect ACh output from the hippocampus. In contrast to the results of septal administration of NMDA and AMPA, local perfusion with the same drugs in the hippocampus caused a decrease in ACh output. Whereas the results of septal administration of drugs indicate that septal cholinergic neurons probably receive excitatory glutamatergic innervation, the decrease in ACh output caused by administration of NMDA and AMPA in the hippocampus is poorly understood.     

Polar lipids of 'Pseudomonas diazotrophicus'

Abstract Reference strains of ' Pseudomonas diazotrophicus ' produce a range of polar lipids atypical of authentic Pseudomonas species. In addition to the phospholipids common in Gram-negative bacteria (phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylethanolamine), N -methylated derivatives of phosphatidylethanolamine (including phosphatidylcholine) and an ornithine amide lipid are also present. The preponderant ester-bound fatty acid (up to 80% of the total) is cis -vaccenic acid ( cis -octadec-11-enoic acid), while 3-hydroxyoctadecanoic acid is the major amide-bound fatty acid in the ornithine lipid. Possible implications of the data for classification of the organism are discussed.     

Utilisation du système Take-set® pour le radiomarquage des médicaments radiopharmaceutiques : exemple de la préparation du pentétréotide marqué à l’indium 111 (Octreoscan®)

The quality of indium 111 radiolabelled pentetreotide preparation (Octreoscan^®, Covidien) depends on several factors among which the use of a special transfer needle (Sterican^®) especially conceived to avoid the metal impurities introduction into the reactionnal medium during labelling. This device, usually provided by the supplier, can exceptionally present defects (twisted needle, folded bevel...) preventing its use for the preparation. In order to manage this risk, we propose in the present technical note an alternative labelling method, based on an adaptation of the original one and using another transfer device, the Take-set^SWAN® system, which permits to obtain high quality Octreoscan^® preparations that meet the product approval specifications.     

Canopy photosynthesis modulates soil respiration in a temperate semi-arid shrubland at multiple timescales

Plant and Soil - Plant growth-promoting bacteria of the genus Bacillus are known to solubilize phosphates and enhance plant growth in many plant species. We explored the effects of the inoculation...     

Ribosome engineering and fermentation optimization leads to overproduction of tiancimycin A,a new enediyne natural product from <Emphasis Type="Italic">Streptomyces</Emphasis> sp. CB03234

Tiancimycin (TNM) A, a recently discovered enediyne natural product from Streptomyces sp. CB03234, showed rapid and complete killing of cancer cells and could be used as a payload in antibody drug conjugates. The low yield of TNM A in the wild-type strain promoted us to use ribosome engineering and fermentation optimization for its yield improvement. The Streptomyces sp. CB03234-R-16 mutant strain with a L422P mutation in RpoB, the RNA polymerase β-subunit, was obtained from the rifamycin-resistant screening. After fermentation optimization, the titers of TNM A in Streptomyces sp. CB03234-R-16 reached to 22.5 ± 3.1 mg L^?1 in shaking flasks, and 13 ± 1 mg L^?1 in 15 L fermentors, which were at least 40-fold higher than that in the wild-type strain (~ 0.3 mg L^?1). Quantitative real-time RT-PCR revealed markedly enhanced expression of key genes encoding TNM A biosynthetic enzymes and regulators in Streptomyces sp. CB03234-R-16. Our study should greatly facilitate the future efforts to develop TNM A into a clinical anticancer drug.     

Interactions among stressors may be weak: Implications for management of freshwater macroinvertebrate communities

Aim

Ecological models that do not account for interactions among stressors, if interactions are important, could be inaccurate and lead to inefficient conservation strategies. Conversely, if interactions are not important (i.e., stressors operate largely independently), then actions concentrating on a stressor‐by‐stressor basis would be warranted. Here, we investigated whether interactions among multiple stressors affected widely used indices of freshwater macroinvertebrate biodiversity, which are sensitive to environmental change at management‐relevant scales (i.e., reaches and catchments).

Location

State of Victoria, south‐eastern Australia.

Methods

We used a 7,418‐sample dataset for stream macroinvertebrates from 2,165 sites distributed over 237,630 km² for 20 years. We calculated the interactive effects on stream macroinvertebrates of stressors operating at different scales, namely vegetation loss at the catchment and reach scales and hydrological change and salinization at the local scale. The importance of interactions among multiple stressors was assessed by comparing the cross‐validated predictive performance of models with and without multiple stressor interaction terms.

Results

Cross‐validated models explained 31%–63% of the variation in the macroinvertebrate responses. The most important stressors were catchment vegetation loss (the proportion of remaining native vegetation cover) and salinity. The inclusion of interaction terms did not increase cross‐validated predictive performance, which indicates that there was little evidence that interactions among stressors were important for explaining variation in commonly used freshwater macroinvertebrate condition indices.

Main conclusions

Interactions among vegetation, salinity and hydrological change stressors may not always be of importance for determining patterns of stream macroinvertebrate biodiversity, so that such interactions may not necessarily be critical considerations for catchment and reach scale management, at least if based on these or comparable condition indices. The mitigation of the impacts of vegetation loss, salinization and hydrological change stressors one‐by‐one probably is sufficient to guide conservation activities and might be advantageous if socio‐political contexts make it difficult to address interactions among stressors.

     

A novel task scheduling approach based on dynamic queues and hybrid meta-heuristic algorithms for cloud computing environment

Task scheduling is one of the most challenging aspects to improve the overall performance of cloud computing and optimize cloud utilization and Quality of Service (QoS). This paper focuses on Task Scheduling optimization using a novel approach based on Dynamic dispatch Queues (TSDQ) and hybrid meta-heuristic algorithms. We propose two hybrid meta-heuristic algorithms, the first one using Fuzzy Logic with Particle Swarm Optimization algorithm (TSDQ-FLPSO), the second one using Simulated Annealing with Particle Swarm Optimization algorithm (TSDQ-SAPSO). Several experiments have been carried out based on an open source simulator (CloudSim) using synthetic and real data sets from real systems. The experimental results demonstrate the effectiveness of the proposed approach and the optimal results is provided using TSDQ-FLPSO compared to TSDQ-SAPSO and other existing scheduling algorithms especially in a high dimensional problem. The TSDQ-FLPSO algorithm shows a great advantage in terms of waiting time, queue length, makespan, cost, resource utilization, degree of imbalance, and load balancing.     

Evaluation of site availability exploitation towards performance optimization in data grids

Data in distributed systems are often replicated into different storage elements in order to facilitate their access. This allows optimizing execution time and bandwidth consumption, ensures load balancing and increases data availability and quality of service. Several replication strategies have then been proposed in the literature. In this work, a new evaluation metric for replication strategies is introduced and experimentally evaluated. This metric, called SAvE, serves to tackle a key feature, although neglected in the literature, which is the ability of a replication strategy to exploit the most available sites in the system. The design of such a metric requires an accurate determination of the availability degree of each site. A new measurement of site availability, denoted SA, is then designed to be integrated into SAvE while overcoming the drawbacks experienced by existing measurements. Extensive experiments are performed using the OptorSim simulator to show the accuracy and the effectiveness of our contributions.     

Nanoantenna-Enhanced Radiative and Anisotropic Decay Rates in Monolayer-Quantum Dots

Plasmonics - Nanoantenna-enhanced ultrafast emission from colloidal quantum dots as quantum emitters is required for fast quantum communications. On-chip integration of such devices requires a...