Toxic and Phenotypic Effects of AAV_Cre Used to Transduce Mesencephalic Dopaminergic Neurons

A popular approach to spatiotemporally target genes using the loxP/Cre recombination system is stereotaxic microinjection of adeno-associated virus (AAV) expressing Cre recombinase (AAV_Cre) in specific neuronal structures. Here, we report that AAV_Cre microinjection in the ventral tegmental area (VTA) of ErbB4 Cyt-1-floxed (ErbB4 Cyt-1^fl/fl) mice at titers commonly used in the literature (~10¹²–10¹³ GC/mL) can have neurotoxic effects on dopaminergic neurons and elicit behavioral abnormalities. However, these effects of AAV_Cre microinjection are independent of ErbB4 Cyt-1 recombination because they are also observed in microinjected wild-type (WT) controls. Mice microinjected with AAV_Cre (10¹²–10¹³ GC/mL) exhibit reductions of tyrosine hydroxylase (TH) and dopamine transporter (DAT) expression, loss of dopaminergic neurons, and they behaviorally become hyperactive, fail to habituate in the open field and exhibit sensorimotor gating deficits compared to controls microinjected with AAV_GFP. Importantly, these AAV_Cre non-specific effects are: (1) independent of serotype, (2) occur with vectors expressing either Cre or Cre-GFP fusion protein and (3) preventable by reducing viral titers by 1000-fold (10¹⁰ GC/mL), which retains sufficient recombination activity to target floxed genes. Our studies emphasize the importance of including AAV_Cre-injected WT controls in experiments because recombination-independent effects on gene expression, neurotoxicity and behaviors could be erroneously attributed to consequences of gene ablation.     

ALADIN: a multilevel testability analyzer for VLSI system design

In order to cope with tomorrow's challenges in the microelectronic market, the reliability of the first phases of the design process must be improved. The possibility of applying techniques for testability analysis at these abstract design levels can considerably help in achieving this goal, reducing at the same time system design costs. In this paper we introduce a novel approach for the application of functional testability at system design level and demonstrate the possibility of its application in an industrial environment. Testability conditions referring to both regular and irregular topologies have been defined, formalized and inserted into the knowledge base of the expert system, ALADIN. This tool operates as a testability analyzer able to identify critical areas for testability in designs whose functional modules and local interconnections are known and described in standard VHDL. The architecture of the tool has been defined in order to satisfy the users' requirements including the integrability into a standard CAD design flow through standard I/O interfaces. Then its application to both a regular and an irregular topology are presented in order to show on real examples which testability conditions apply, and how the tool operates in order to reach the testability assessment. From these industrial case studies, figures of merit are derived from which it is possible to evaluate the importance of the application of such a methodology to system level design     

Considerations about learning Word2Vec

The Journal of Supercomputing - Despite the large diffusion and use of embedding generated through Word2Vec, there are still many open questions about the reasons for its results and about its real...     

On field characterisation of static domestic gas flowmeters

Different solutions to the metering of natural gas consumption can be adopted according to whether the distribution is domestic or industrial. In the domestic field, almost all the flow meters used by natural gas distribution companies are conventional diaphragm meters, whereas greater flow rates justify metrologically better performing measurement systems. The requirement for new safety and remote-reading related functions and the availability of new technologies is now encouraging the use of static innovative flow meters. In the present study, after a short analysis of metering principles and of static ultrasonic flow meter characteristics, the authors report the results of the field tests carried out on two different types of static ultrasonic flow meter for 2 years.     

Uncertainty Budget of the SMPS–APS System in the Measurement of PM1, PM2.5, and PM10

The effects of particulate matter on environment and public health have been widely studied in recent years. In spite of the presence of numerous studies about this topic there is no agreement on the relative importance of the particles' size and origin with respect to health effects among researchers. Nevertheless, air quality standards are moving, as the epidemiological attention, towards greater focus on the smaller particles. The most reliable method used in measuring particulate matter (PM) is the gravimetric method since it directly measures PM concentration, guaranteeing an effective traceability to international standards. This technique, however, neglects the possibility to correlate short term intraday atmospheric parameter variations that can influence ambient particle concentration and size distribution as well as human activity patterns. Besides, a continuous method to determine PM concentrations through the measurement of the number size distribution is the system constituted by a Scanning Mobility Particle Sizer (SMPS) and an Aerodynamic Particle Sizer (APS). In this article, the evaluation of the uncertainty budget in measuring PM through the SMPS–APS system, as well as a metrological comparison with the gravimetric reference method in order to analyze the compatibility, was carried out and applied with reference to an experimental campaign developed in a rural site. This choice allowed to assume the hypothesis of spherical particle morphology. The average PM₁₀, PM_2.5, and PM₁ uncertainties obtained for the SMPS–APS system are equal to 27%, 29%, and 31%, respectively. Here the principle influence parameter is the particle density that has to be directly measured with low uncertainty in order to reduce the PM uncertainty.