Voluntary nicotine consumption triggers in vivo potentiation of cortical excitatory drives to midbrain dopaminergic neurons

International audienceActive response to either natural or pharmacological reward causes synaptic modifications to excitatory synapses on dopamine (DA) neurons of the ventral tegmental area (VTA). Here, we examine these modifications using nicotine, the main addictive component of tobacco, which is a potent regulator of VTA DA neurons. Using an in vivo electrophysiological technique, we investigated the role of key components of the limbic circuit, the infralimbic cortex (ILCx) and the bed nucleus of the stria terminalis (BNST), in operant behaviors related to nicotine reward. Our results indicated that nicotine self-administration in rats, but not passive delivery, triggers hyperactivity of VTA DA neurons. The data suggest that potentiation of the ILCx-BNST excitatory pathway is involved in these modifications in VTA DA neurons. Thus, recruitment of these specific excitatory inputs to VTA DA neurons may be a neural correlate for the learned association between active responding and the reward experience

Ultrafast dynamics in unaligned MWCNTs decorated with metal nanoparticles

The relaxation dynamics of unaligned multi-walled carbon nanotubes decorated with metallic nanoparticles have been studied by using transient optical measurements. The fast dynamics due to the short-lived free-charge carriers excited by the pump are not affected by the presence of nanoparticles. Conversely, a second long dynamics, absent in bare carbon nanotubes, appears only in the decorated samples. A combination of experiment and theory allows us to ascribe this long dynamics to relaxation channels involving electronic states localized at the tube-nanoparticle interface

Vacuum local and global electromagnetic self-energies for a point-like and an extended field source

We consider the electric and magnetic energy densities (or equivalently field fluctuations) in the space around a point-like field source in its ground state, after having subtracted the spatially uniform zero-point energy terms, and discuss the problem of their singular behavior at the source's position. We show that the assumption of a point-like source leads, for a simple Hamiltonian model of the interaction of the source with the electromagnetic radiation field, to a divergence of the renormalized electric and magnetic energy density at the position of the source. We analyze in detail the mathematical structure of such singularity in terms of a delta function and its derivatives. We also show that an appropriate consideration of these singular terms solves an apparent inconsistency between the total field energy and the space integral of its density. Thus the finite field energy stored in these singular terms gives an important contribution to the self-energy of the source. We then consider the case of an extended source, smeared out over a finite volume and described by an appropriate form factor. We show that in this case all divergences in local quantities such as the electric and the magnetic energy density, as well as any inconsistency between global and space-integrated local self-energies, disappear.Comment: 8 pages. The final publication is available at link.springer.co

A guided tour of asynchronous cellular automata

Research on asynchronous cellular automata has received a great amount of attention these last years and has turned to a thriving field. We survey the recent research that has been carried out on this topic and present a wide state of the art where computing and modelling issues are both represented.Comment: To appear in the Journal of Cellular Automat

Laparoscopic Cytoreduction Combined with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Peritoneal Surface Malignancies (PSM): Italian PSM Oncoteam Evidence and Literature Review

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has gained increasing acceptance in clinical practice. Performing CRS and HIPEC laparoscopically represents a challenging and intriguing technical evolution. However, the experiences are limited, and the evidence is low. This retrospective analysis was performed on patients treated with laparoscopic CRS-HIPEC within the Italian Peritoneal Surface Malignancies Oncoteam. Clinical, perioperative, and follow-up data were extracted and collected on prospectively maintained databases. We added a systematic review according to the PRISMA method for English-language articles through April 2022 using the keywords laparoscopic, hyperthermic, HIPEC, and chemotherapy. From 2016 to 2022, fourteen patients were treated with Lap-CRS-HIPEC with curative intent within the Italian centers. No conversion to open was observed. The median duration of surgery was 487.5 min. The median Peritoneal Cancer Index (PCI) was 3, and complete cytoreduction was achieved in all patients. Two patients (14.3%) had major postoperative complications, one requiring reintervention. After a median follow-up of 16.9 months, eleven patients were alive without disease (78.6%), two patients developed recurrence (14.3%), and one patient died for unrelated causes (7.1%). The literature review confirmed these results. In conclusion, current evidence shows that Lap-CRS-HIPEC is feasible, safe, and associated with a favorable outcome in selected patients. An accurate patient selection will continue to be paramount in choosing this treatment

Researching the use of force: The background to the international project

This article provides the background to an international project on use of force by the police that was carried out in eight countries. Force is often considered to be the defining characteristic of policing and much research has been conducted on the determinants, prevalence and control of the use of force, particularly in the United States. However, little work has looked at police officers’ own views on the use of force, in particular the way in which they justify it. Using a hypothetical encounter developed for this project, researchers in each country conducted focus groups with police officers in which they were encouraged to talk about the use of force. The results show interesting similarities and differences across countries and demonstrate the value of using this kind of research focus and methodology

MONITORIZAÇÃO DE MICROALGAS PLANCTÔNICAS POTENCIALMENTE TÓXICAS NA ÁREA DE MARICULTURA DA ENSEADA DE ARMAÇÃO DE ITAPOCOROY - PENHA - SC

This paper is a descriptive synthesis of approximately 17 months of phytoplankton sampling in the shellfish culture area of Enseada de Armação do Itapocoroy (Penha - Santa Catarina - Brazil). The goal of this program was to know the local phytoplankton composition, specially the toxic and potentially toxic ones; to verify the characteristics of water masses associated to the different phytoplankton assemblies and to monitor the occurrence of blooms of toxic or potentially toxic species, in order to prevent human intoxication by ingestion of contaminated shellfish. The results have indicated the occurrence of seasonal patterns in species succession. Potential producers of diarrhetic toxins tend to occur in winter and spring. From late spring to late summer the occurrence of Trichodesmium spp. indicate the possible presence of cyanobacteria toxins. Alexandrium fraterculus - a potential producer of paralytic toxin - has ocurred only in low cell densities and mainly in winter.O presente trabalho trata-se de uma síntese de aproximadamente 17 meses de amostragens de fitoplâncton na área de maricultura da Enseada de Armação do Itapocoroy, município de Penha, Santa Catarina. Os objetivos foram conhecer as principais espécies de microalgas planctônicas ocorrentes no local, especialmente as espécies tóxicas ou potencialmente tóxicas; verificar as características das massas de água associadas às diferentes espécies ou assembléias de microalgas (salinidade, temperatura e transparência) e monitorar a ocorrência de densidades elevadas de espécies tóxicas ou potencialmente tóxicas para prevenir possíveis intoxicações pela ingestão de moluscos com acúmulo de ficotoxinas. Os resultados indicam a ocorrência de padrões sazonais de sucessão de espécies. Espécies potencialmente produtoras de toxinas diarréicas e amnésicas tendem a ocorrer nos meses de inverno e primavera. Entre o final da primavera e durante o verão a ocorrência de Trichodesmium spp. indica possibilidade de toxinas de cianobactérias. Alexandrium fraterculus - um potencial produtor de toxina paralisante - ocorreu em pequenas densidades e principalmente no inverno