The behavioral relevance of a modular organization in the lateral habenula.

Behavioral strategies for survival rely on the updates the brain continuously makes based on the surrounding environment. External stimuli-neutral, positive, and negative-relay core information to the brain, where a complex anatomical network rapidly organizes actions, including approach or escape, and regulates emotions. Human neuroimaging and physiology in nonhuman primates, rodents, and teleosts suggest a pivotal role of the lateral habenula in translating external information into survival behaviors. Here, we review the literature describing how discrete habenular modules-reflecting the molecular signatures, anatomical connectivity, and functional components-are recruited by environmental stimuli and cooperate to prompt specific behavioral outcomes. We argue that integration of these findings in the context of valence processing for reinforcing or discouraging behaviors is necessary, offering a compelling model to guide future work

Heat transfer delay method for the fluid velocity evaluation in a multi-turn pulsating heat pipe

A multi-turn closed loop pulsating heat pipe made of aluminium is tested in vertical bottom heated mode and different condenser temperatures with the aim of providing quantitative information regarding its flow dynamics through a novel post-processing technique on the local wall-to-fluid heat flux, evaluated within the adiabatic section. The studied device is made of an annealed aluminium tube (inner/outer diameter: 3/5 mm), folded in 14 turns and partially filled with methanol (volumetric filling ratio: 50%). The aluminium channels are coated with a high-emissivity opaque paint, thus allowing thermographic measurements on the outer wall by means of a high-resolution medium wave infrared camera. The proposed method, named Heat Transfer Delay Method, is validated by means of a dedicated experimental approach. Then, the acquired time-space temperature maps are used as input data for the inverse heat conduction problem resolution approach to estimate the local convective heat flux locally exchanged at the inner wall-fluid interface. The resulting wall-to-fluid heat fluxes are then post- processed by applying the Heat Transfer Delay Method to the oscillatory and circulatory flow modes. The average fluid velocity is assessed at varying working conditions during the circulatory flow, finding values up to 0.77 m/s and 0.3 m/s for condenser temperature equal to 20 ◦C and 10 ◦ C, respectivel

Student perceptions of interpersonal justice, engagement, agency and anger: a longitudinal study for reciprocal effects

Based on the premise that classroom interactions unfold through a complex series of circular influences between teacher and students, the aim of this longitudinal study was to test a reciprocal effects model connecting students’ perceptions of interpersonal justice, on the one hand, and student engagement, agency and anger, on the other. Self-report measures of interpersonal justice, student engagement, agency and anger were collected from 454 Year Nine students from Northern Italy in a 3-wave longitudinal research design. Structural equation modelling with latent variables indicated that interpersonal justice in wave 1 had a negative effect on both student agency and anger in wave 2, while interpersonal justice in wave 2 only negatively predicted student anger in wave 3. With respect to the reciprocal effects, student engagement in wave 2 was found to positively predict interpersonal justice in wave 3, while a negative effect close to statistical significance was observed from student agency in wave 2 to interpersonal justice in wave 3. These results are discussed in terms of their implications for teacher practice, as they emphasize that (a) the two main facets of student participation, namely engagement and agency, are differently interconnected with the learning environment, and (b) the perception of being treated fairly is important to the point that its deficiency triggers a persistent feeling of anger in students

Dental injuries in young athletes, a five-year follow-up study

Aim The aim of this study is to produce a clinical therapy protocol for a group of 20 athletes between the ages of 8 and 14, who all suffered traumas affecting hard dental and periodontal tissues. Material and methods This study involves a group of 20 athletes (10 male and 10 female) who had suffered dental traumas of varying severity. In order to collect the data, two classification systems were used: one for hard tissue traumas and another for periodontal lesions. The athletes were subdivided into lesion groups, treated depending on the type of lesions and then followed-up over a period of 5 years. A statistical analysis was carried out to study the association between type of lesions, types of sports and the number of teeth involved. Results We found that recovery time ranged from 3 to 5 days for uncomplicated fractures and up to 14 days for luxations. Only four complications were registered during the follow-up period and these were most likely due to the severity of the trauma. Out of the 20 athletes, 16 had begun and maintained the habit of using mouth protection devices when practicing their sport. The statistical analysis focused on the possible association between the risk levels of a sport and the typical lesions and complications that usually occur. Due to their high frequency, the two types of lesions taken into account in our study were complicated fractures (FP) and luxated/fractured teeth (LF). The average number of teeth involved varied according to the sport's risk level (medium or high) with averages of 1.6 teeth involved for medium-risk sports and 2.0 teeth for high-risk sports. Conclusions What emerged in particular was the regular progress in the recovery time needed for the injuries sustained, with few complications or delays in rehabilitation; we also noted that the numerous athletes who habitually used mouthguards while competing during the recovery period did not suffer any recurrences of injuries or further complications. Regarding the results of our statistical analysis, no association was found between the sport's risk, the types of lesions and the occurrence of complications. In addition, analysis of the average number of teeth involved showed that there is no statistical evidence to reject the hypothesis that the ratios remain the same in the two groups

Closed Loop Pulsating Heat Pipes: Ground and Microgravity experiments

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Numerical Simulation of a Capillary Pulsating Heat Pipe in Various Gravity Conditions

In the last two decades a new concept of capillary heat pipe without wick structures, commonly known as Pulsating Heat Pipe (PHP), entered the domain of the two-phase passive heat transfer devices. The thermal-hydraulic behavior of this mini-channel with alternate heating and cooling zones, evacuated and partially filled with a working fluid, mainly depends on the interplay between phase change phenomena, capillary and gravity, if present, which may assist or damp the fluid motion. Numerous are the attempts to simulate PHPs complex behavior, but only a few of them are capable of complete thermal-hydraulic simulations; in addition, none is able to predict the effects of various gravity levels. Nevertheless, validated numerical simulations can constitute useful tools to complete and support experimental studies, and to help the design of new and better performing PHPs. Thus, a novel lumped parameters numerical code for the transient thermo-hydraulic simulation of PHPs has been developed and validated. It consists of a two-phase separated flow model where capillary slug flow is assumed a priori. A complete set of balance differential equations accounts for homogeneous and heterogeneous phase-changes, as well as thermal and fluid-dynamic phenomena. This novel model shows a very good quantitative and qualitative prediction capability not only when computing the correct measured equivalent thermal resistance, but even when reproducing the experimental trend of temperature when transient conditions are applied. This paper presents the comparison between numerical and experimental data, for a copper PHP (I.D./O.D. 1.1mm/2.0mm) filled with FC-72 tested experimentally in micro-gravity (58th Parabolic Flight Campaign), and hyper-gravity conditions (ESA SYT!2013 Programme

Fluid-flow pressure measurements and thermo-fluid characterization of a single loop two-phase passive heat transfer device

Abstract A Novel Single Loop Pulsating Heat Pipe (SLPHP), with an inner diameter of 2 mm, filled up with two working fluids (Ethanol and FC-72, Filling Ratio of 60%), is tested in Bottom Heated mode varying the heating power and the orientation. The static confinement diameter for Ethanol and FC-72, respectively 3.4 mm and 1.7mm, is above and slightly under the inner diameter of the tube. This is important for a better understanding of the working principle of the device very close to the limit between the Loop Thermosyphon and Pulsating Heat Pipe working modes. With respect to previous SLPHP experiments found in the literature, such device is designed with two transparent inserts mounted between the evaporator and the condenser allowing direct fluid flow visualization. Two highly accurate pressure transducers permit local pressure measurements just at the edges of one of the transparent inserts. Additionally, three heating elements are controlled independently, so as to vary the heating distribution at the evaporator. It is found that peculiar heating distributions promote the slug/plug flow motion in a preferential direction, increasing the device overall performance. Pressure measurements point out that the pressure drop between the evaporator and the condenser are related to the flow pattern. Furthermore, at high heat inputs, the flow regimes recorded for the two fluids are very similar, stressing that, when the dynamic effects start to play a major role in the system, the device classification between Loop Thermosyphon and Pulsating Heat Pipe is not that sharp anymore