Post-Fire Management Impact on Natural Forest Regeneration through Altered Microsite Conditions

High severity stand-replacing wildfires can deeply affect forest ecosystems whose composition includes plant species lacking fire-related traits and specific adaptations. Land managers and policymakers need to be aware of the importance of properly managing these ecosystems, adopting post-disturbance interventions designed to reach management goals, and restoring the required ecosystem services. Recent research frequently found that post-fire salvage logging negatively affects natural regeneration dynamics, thereby altering successional pathways due to a detrimental interaction with the preceding disturbance. In this study, we compared the effects of salvage logging and other post-disturbance interventions (adopting different deadwood management strategies) to test their impact on microclimatic conditions, which potentially affect tree regeneration establishment and survival. After one of the largest and most severe wildfires in the Western Alps that affected stand-replacing behavior (100% tree mortality), a mountain forest dominated by Pinus sylvestris L., three post-fire interventions were adopted (SL-Salvage Logging, logging of all snags; CR-Cut and Release, cutting snags and releasing all deadwood on the ground; NI-No Intervention, all snags left standing). The differences among interventions concerning microclimatic conditions (albedo, surface roughness, solar radiation, soil moisture, soil temperature) were analyzed at different spatial scales (site, microsite). The management interventions influenced the presence and density of safe sites for regeneration. Salvage logging contributed to the harsh post-fire microsite environment by increasing soil temperature and reducing soil moisture. The presence of deadwood, instead, played a facilitative role in ameliorating microclimatic conditions for seedlings. The CR intervention had the highest soil moisture and the lowest soil temperature, which could be crucial for seedling survival in the first post-fire years. Due to its negative impact on microclimatic conditions affecting the availability of preferential microsites for regeneration recruitment, salvage logging should not be considered as the only intervention to be applied in post-fire environments. In the absence of threats or hazards requiring specific management actions (e.g., public safety, physical hazards for facilities), in the investigated ecosystems, no intervention, leaving all deadwood on site, could result in better microclimatic conditions for seedling establishment. A preferred strategy to speed-up natural processes and further increase safe sites for regeneration could be felling standing dead trees whilst releasing deadwood (at least partially) on the ground

Behavioral responses in people affected by alcohol use disorder and psychiatric comorbidity: correlations with addiction severity

Aim. In this study, we investigated in people suffering from alcohol use disorder (AUD) with or without dual diagnosis (concomitant psychiatric disability) how they feel their dependence condition. We predicted that AUD people with a dual diagnosis could feel potentiated their addiction.Methods. Alcohol habits and psychiatric conditions of 183 AUD men and 62 AUD women were measured by using the DSM-5, the severity of alcohol dependence questionnaire (SADQ), the alcohol anamnesis and psychiatric examination by the symptom check list 90-R (SCL-90-R).Results. We have shown that alcohol drinking does not correlate with both psychiatric examination and self-reported psychopathology. SADQ shows that severe alcohol dependence correlates with highest psychiatric symptoms and with the levels of alcohol consumption.Conclusions. This finding suggests that high SADQ scores may represent a tool to early disclose only patients with dual diagnosis. SADQ may provide information to address pharmacological interventions because revealing aspects of the dark side of addiction potentiated by AUD associated psychopathology.

A Path to the Stars: The Evolution of the Species

During the last years, a number of telescopes have been dedicated to the followup of the GRBs. But after the Swift launch, the average observed intensity of the GRBs showed to be lower than thought before. Our experience with the robotic 60 cm REM telescope confirmed this evidence, with a large number oflostGRBs. Then, we proposed to study the feasibility of a 4 m fast pointing class telescope, equipped with a multichannel imagers, from Visible to Near Infrared. In this paper, we present the main result of the feasibility study we performed so far

High Risk of Secondary Infections Following Thrombotic Complications in Patients With COVID-19

Background. This study’s primary aim was to evaluate the impact of thrombotic complications on the development of secondary infections. The secondary aim was to compare the etiology of secondary infections in patients with and without thrombotic complications. Methods. This was a cohort study (NCT04318366) of coronavirus disease 2019 (COVID-19) patients hospitalized at IRCCS San Raffaele Hospital between February 25 and June 30, 2020. Incidence rates (IRs) were calculated by univariable Poisson regression as the number of cases per 1000 person-days of follow-up (PDFU) with 95% confidence intervals. The cumulative incidence functions of secondary infections according to thrombotic complications were compared with Gray’s method accounting for competing risk of death. A multivariable Fine-Gray model was applied to assess factors associated with risk of secondary infections. Results. Overall, 109/904 patients had 176 secondary infections (IR, 10.0; 95% CI, 8.8–11.5; per 1000-PDFU). The IRs of secondary infections among patients with or without thrombotic complications were 15.0 (95% CI, 10.7–21.0) and 9.3 (95% CI, 7.9–11.0) per 1000-PDFU, respectively (P = .017). At multivariable analysis, thrombotic complications were associated with the development of secondary infections (subdistribution hazard ratio, 1.788; 95% CI, 1.018–3.140; P = .043). The etiology of secondary infections was similar in patients with and without thrombotic complications. Conclusions. In patients with COVID-19, thrombotic complications were associated with a high risk of secondary infections

Natural convection in a square cavity with discrete heat sources: an experimental and numerical analysis

Lo studio della convezione naturale in cavità quadrata con sorgenti discrete è svolto sia sperimentalmente che numericamente. Sperimentalmente attraverso l'interferometria olografica e il Particle Image Velocimetry mentre numericamente attraverso l'utilizzo del software CFD ANSYS Fluent. Sono presentati 7 diversi studi di configurazioni della cavità dove vengono esaminati gli effetti sulla trasmissione di calore della dimensione delle sorgenti, dell'aspect ratio, della presenza di uno o due ostacoli orizzontali o verticali di diversa lunghezza e della presenza di una quinta sorgente al centro della cavità. I risultati ottenuti dalle prove sperimentali e numeriche sono stati analizzati e confrontati nella forma di isoterme, streamlines, velocity maps e numero di Nusselt per numeri di Rayleigh da 2∙103 a 5∙105. E' stato studiata e sviluppata una correlazione tra il numero di Nusselt medio e il numero di Rayleigh per ogni configurazione. I risultati evidenziano le influenze delle modifiche apportate alla cavità sulla convezione naturale. L'applicazione industriale della cavità stabilirà poi la scelta dei parametri di progetto: se il progetto necessita di uno scambio termico maggiore, dovranno essere scelte le proporzioni e la ripartizione delle fonti di calore in modo appropriato, riducendo o eliminando la presenza di ostacoli nella cavità in modo di avere un maggiore scambio termico.Natural convection in a square cavity with discrete heat sources is studied both experimentally and numerically. The results are presented for Rayleigh numbers from 2∙103 to 5∙105. The experimental techniques employed are Holographic Interferometry and Particle Image Velocimetry. ANSYS Fluent is the CFD software chosen for the numerical analysis. The case studies performed examine how heat transfer in the cavity is affected by modifying its characteristics. Case study 1 tests the influence of the heat sources’ size on heat transfer. The influence of cavity aspect ratio and presence of a baffle is studied in case study 2. Case Study 3 explores the effect baffle length has on natural convection in an enclosure. The effect of the length of a pair of horizontal baffles on natural convection is tested in case study 4. Case study 5 examines the effect the height of a pair of vertical baffles has on natural convective heat transfer in a cavity. The final case studies introduce a fifth heat source on the bottom cavity wall of a cavity with four heat sources. In case study 6, the effect of the position of the fifth heat source on natural convection in the cavity is analyzed. In case study 7, the effect of two heating configurations on heat transfer is evaluated. The results obtained from the experimental and numerical tests in the form of isotherms, streamlines, velocity maps and average Nusselt numbers are analyzed and compared. A correlation between the average Nusselt and Rayleigh numbers for each configuration was studied and developed. The results showed that the characteristics altered in the case studies presented, modify heat transfer inside an enclosure. The intended application of the cavity will establish the choice of its design parameters: if natural convection is to be maximized, the aspect ratio and allocation of the heat sources will be chosen so as to have a greater temperature and fluid flow, reducing or eliminating the presence of baffles in the enclosure

Experimental and numerical analysis of the effect of the position of a bottom wall hot source on natural convection

An experimental and numerical analysis of natural convection in a square cavity with partially active thermal side walls and an additional active source located in the center of the bottom wall is investigated for Rayleigh numbers ranging from 104 to 105. The analysis was carried out experimentally through holographic interferometry and numerically using CFD software. Interferograms, streamlines, isotherms and velocity maps are analyzed for three different positions of the hot source. The square cavity of dimensionless height H is made of Plexiglas with four cold sources and a hot source. The sources are made of aluminum and their dimensionless height is HS = 0.25. The hot source is placed on the bottom cavity wall and its dimensionless position varies from D = 0.4 (corresponds to the middle of the bottom of the cavity) to D = 0.6. The results clearly show that different positions of the hot source have an effect on heat transfer. Two vortices develop inside the cavity. In the symmetrical position, the vortices are independent of Rayleigh number while in the other two configurations the left vortex becomes larger than the right one. D = 0.4 is the best position of the hot source in order to create the fastest velocity field able to remove the heat generated in the cavity in the best way