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Landscape fires, predominantly found in the frequently burning global savannas, are a substantial source of greenhouse gases and aerosols. The impact of these fires on atmospheric composition is partially determined by the chemical breakup of the constituents of the fuel into individual emitted chemical species, which is described by emission factors (EFs). These EFs are known to be dependent on, amongst other things, the type of fuel consumed, the moisture content of the fuel, and the meteorological conditions during the fire, indicating that savanna EFs are temporally and spatially dynamic. Global emission inventories, however, rely on static biome-averaged EFs, which makes them ill-suited for the estimation of regional biomass burning (BB) emissions and for capturing the effects of shifts in fire regimes. In this study we explore the main drivers of EF variability within the savanna biome and assess which geospatial proxies can be used to estimate dynamic EFs for global emission inventories. We made over 4500 bag measurements of CO2, CO, CH4, and N2O EFs using a UAS and also measured fuel parameters and fire-severity proxies during 129 individual fires. The measurements cover a variety of savanna ecosystems under different seasonal conditions sampled over the course of six fire seasons between 2017 and 2022. We complemented our own data with EFs from 85 fires with locations and dates provided in the literature. Based on the locations, dates, and times of the fires we retrieved a variety of fuel, weather, and fire-severity proxies (i.e. possible predictors) using globally available satellite and reanalysis data. We then trained random forest (RF) regressors to estimate EFs for CO2, CO, CH4, and N2O at a spatial resolution of 0.25∘ and a monthly time step. Using these modelled EFs, we calculated their spatiotemporal impact on BB emission estimates over the 2002–2016 period using the Global Fire Emissions Database version 4 with small fires (GFED4s). We found that the most important field indicators for the EFs of CO2, CO, and CH4 were tree cover density, fuel moisture content, and the grass-to-litter ratio. The grass-to-litter ratio and the nitrogen-to-carbon ratio were important indicators for N2O EFs. RF models using satellite observations performed well for the prediction of EF variability in the measured fires with out-of-sample correlation coefficients between 0.80 and 0.99, reducing the error between measured and modelled EFs by 60 %–85 % compared to using the static biome average. Using dynamic EFs, total global savanna emission estimates for 2002–2016 were 1.8 % higher for CO, while CO2, CH4, and N2O emissions were, respectively, 0.2 %, 5 %, and 18 % lower compared to GFED4s. On a regional scale we found a spatial redistribution compared to GFED4s with higher CO, CH4, and N2O EFs in mesic regions and lower ones in xeric regions. Over the course of the fire season, drying resulted in gradually lower EFs of these species. Relatively speaking, the trend was stronger in open savannas than in woodlands, where towards the end of the fire season they increased again. Contrary to the minor impact on annual average savanna fire emissions, the model predicts localized deviations from static averages of the EFs of CO, CH4, and N2O exceeding 60 % under seasonal conditions.

Landscape fires are a significant contributor to atmospheric burdens of greenhouse gases and aerosols. Although many studies have looked at biomass burning products and their fate in the atmosphere, estimating and tracing atmospheric pollution from landscape fires based on atmospheric measurements are challenging due to the large variability in fuel composition and burning conditions. Stable carbon isotopes in biomass burning (BB) emissions can be used to trace the contribution of C3 plants (e.g. trees or shrubs) and C4 plants (e.g. savanna grasses) to various combustion products. However, there are still many uncertainties regarding changes in isotopic composition (also known as fractionation) of the emitted carbon compared to the burnt fuel during the pyrolysis and combustion processes. To study BB isotope fractionation, we performed a series of laboratory fire experiments in which we burned pure C3 and C4 plants as well as mixtures of the two. Using isotope ratio mass spectrometry (IRMS), we measured stable carbon isotope signatures in the pre-fire fuels and post-fire residual char, as well as in the CO2, CO, CH4, organic carbon (OC), and elemental carbon (EC) emissions, which together constitute over 98 % of the post-fire carbon. Our laboratory tests indicated substantial isotopic fractionation in combustion products compared to the fuel, which varied between the measured fire products. CO2, EC, and residual char were the most reliable tracers of the fuel 13C signature. CO in particular showed a distinct dependence on burning conditions; flaming emissions were enriched in 13C compared to smouldering combustion emissions. For CH4 and OC, the fractionation was the other way round for C3 emissions (13C-enriched) and C4 emissions (13C-depleted). This indicates that while it is possible to distinguish between fires that were dominated by either C3 or C4 fuels using these tracers, it is more complicated to quantify their relative contribution to a mixed-fuel fire based on the δ13C signature of emissions. Besides laboratory experiments, we sampled gases and carbonaceous aerosols from prescribed fires in the Niassa Special Reserve (NSR) in Mozambique, using an unmanned aerial system (UAS)-mounted sampling set-up. We also provided a range of C3:C4 contributions to the fuel and measured the fuel isotopic signatures. While both OC and EC were useful tracers of the C3-to-C4 fuel ratio in mixed fires in the lab, we found particularly OC to be depleted compared to the calculated fuel signal in the field experiments. This suggests that either our fuel measurements were incomprehensive and underestimated the C3:C4 ratio in the field or other processes caused this depletion. Although additional field measurements are needed, our results indicate that C3-vs.-C4 source ratio estimation is possible with most BB products, albeit with varying uncertainty ranges.

Introduction Posttraumatic Stress Disorder (PTSD) consists of an intense, prolonged, and occasionally delayed reaction to a deeply stressful event. PTSD is associated with risk of suicide and chronic psychological impairment. The continued exposure to stress suffered by Healthcare Workers (HCWs) during the COVID-19 pandemic can be considered a mass traumatic event and contribute to higher rates of PTSD in this population. Objectives To study the rates of PTSD in a sample group of healthcare professionals working in a Portuguese general hospital and its relationship with a number of individual variables considered to be relevant by the existing literature on the subject. Methods We devised a survey to assess the prevalence of PTSD among HCWs in a general hospital and its relationship with sex, social support, profession, work experience in healthcare, time spent caring for COVID-19 patients and place in which the COVID-19-related activities were carried out. PTSD symptoms were assessed using the PCL-5, Portuguese version. Results A total of 226 HCWs were included in the study. Provisional diagnosis of PTSD was made based on the PCL-5 responses, considering DSM-5 criteria and the cutoff score of 33. 79 out of 226 (35.0%) HCWs had a provisional diagnosis of PTSD, and a significant association was found between PTSD and time spent working with COVID-19 patients and between PTSD and place of work, namely the COVID-19 Emergency Room and Intensive Care Unit. Conclusions Our results are in line with previous studies, highlighting the importance of a serious, wide, and honest discussion about mental health promotion among HCWs. The COVID-19 pandemic has been an undeniable source of stress for HCWs around the globe, and the consequences of this stress are beginning to manifest themselves. It is urgent that this reflection takes place, as it is of paramount importance that what we all have lived in the past years serves as a lesson, and not as a warning of a crisis doomed to repeat itself. Disclosure of Interest None Declared

Introduction PTSD is a chronic, debilitating condition with limited treatment efficacy. Accessing traumatic memories often leads to overwhelming distress, impacting treatment process. Current approved pharmacological treatments have exhibited small to moderate effects when compared with placebo. Evidence suggests 3,4,-methylene-dioxymethamphetamine(MDMA)-assisted psychotherapy as a viable option for refractory PTSD. Objectives Comprehensive review of early clinical research, proposed mechanisms, safety and emerging therapeutic models. Methods Eligible studies will be identified through strategic search of MEDLINE. Results Pre-clinical and imaging studies suggest memory reconsolidation and fear extinction as candidate psychological and neurological mechanisms, involving MDMA’s combined effects of increasing serotonergic activity, as well the release of oxytocin and brain-derived neurotrophic factor in key memory and emotional circuits. Resulting reduction in amygdala and insula activation and increasing connectivity between the amygdala and hippocampus may create a “tolerance window” of neuroplasticity for emotional engagement and reprocessing of traumatic memories during psychotherapy. Early clinical trials report impressive and durable reduction in PTSD symptoms, with a safety profile comparable to that of SSRIs. A recently completed randomized, double-blind, placebo-controlled phase 3 trial reported full remission of PTSD symptoms in 67% of patients at 2 months, with no increase in suicidality, cardiovascular events or abuse behavior. Emerging treatment models underline the importance of unmedicated therapeutic sessions for preparation for the experience and subsequent integration as essential for full benefit and safety of the clinical context. Conclusions The psychological impact associated with the COVID-19 pandemic is an reminder of the emotional and economic burden associated with PTSD. MDMA-assisted therapy may be a breakthrough approach meriting further multidisciplinary investment and clinical research. Disclosure No significant relationships.

AbstractIntroduction Calcium phosphate cements (CPCs) have been widely used for bone defect´s filling given their excellent biocompatibility, osteoconduction ability and ease of manipulation [1]. Nevertheless, their mechanical properties and handling performance still need to be improved to satisfy clinical requirements. Indeed, enhancing their injectability can widen its application to minimally invasive surgical procedures [2]. This work aims to investigate the effect of the liquid phase amount and presence of hydroxypropyl methyl cellulose (HPMC) on the basic properties of a commercial CPC containing a polymeric adjuvant, chitosan (Chi).Materials and methods Starting from the original formulation containing Chi, samples with different amounts of liquid phase (LP 30%, 38%, 42%, 50%) were prepared. Additionally, for LP 38% and 42% formulations, Chi was replaced by HPMC polymer. Setting times were measured using the Vicat apparatus. After 6 days of setting, mechanical properties were studied through compression assays and Vickers hardness was measured. Injectability experiments were done and the cytotoxicity of the commercial CPC was assessed using MG63 and NIH/3T3 cell lines following the ISO 10993-5 guidelines.Results As shown in Table 1, increasing the LP content from 30% to 50% increased the initial setting time from 6.5 min to 24 min, and the final setting time from 7.5 min to 32 min. Concerning the resistance to compression, it was lowered from 9.53 ± 1.00 MPa to 0.83 ± 0.20 MPa. Regarding materials’ hardness, it decreased by 77%. Injectability measurements showed that only 38% and 42%LP formulations could be injected. Nonetheless, while 38%LP formulation presented an injectability of 31 ± 2%, 42%LP formulation showed an injectability of 91 ± 1%. As for the addition of HPMC, for 38%LP formulation an initial setting time of 6.5 min and a final setting time of 10.5 min were measured, and for 42%LP formulation 12 min and 14.5 min, respectively. The mechanical properties presented similar values regardless the added polymer. Moreover, the formulations containing HPMC presented 69 ± 6% injectability for 38%LP and 94 ± 1% for 42%LP. Finally, when in contact with extracts of the commercial CPC for 24 h, the studied cell lines presented viability greater than 75% when compared to unexposed cells. Discussion and conclusions: Our study shows that LP content has a significant impact on the CPC studied properties. Effectively, for 38 and 42%LP the setting times, resistance to compression and hardness of the materials assume suitable values for their use as trabecular bone defect fillers. For the Chi CPC, 42%LP formulation is ∼200% more injectable than the 38%LP one. Even though the replacement of Chi by HPMC does not affect the mechanical properties significantly, HPMC itself seems to promote injectability, increasing it by 126%. Finally, the commercial CPC does not show a cytotoxic effect under the conditions of this assay.Table 1. Effect of the LP content on the properties of the Chi containing CPC.[Table: see text]

Introduction Attention-Deficit/Hyperactivity Disorder (ADHD) and Obesity are frequently comorbid. The prevalence of ADHD rises from around 2.8% in the general population (adults) to about 27% among those with obesity. Although neurobiological mechanisms explaining the strong association between ADHD and obesity are still unclear, several hypotheses have been proposed to explain the high comorbidity, including common genes, dopaminergic neurotransmission, deficits in executive functions (planning, adherence to weight loss programs or protocols after bariatric surgery) and circadian rhythm dysregulation. Objectives Review on the relationship between ADHD and Obesity, focusing on possible biological mechanisms driving their high comorbidity. Methods We conducted a search in PubMed and ClinicalKey with the terms: “Attention-Deficit/Hyperactivity Disorder”, “Obesity”, “Dopamine”. Results Altered reward processing and impaired inhibitory control are key features of ADHD and are also related to obesity. The ability to resist the impulse to eat and an appropriate reward response require normal function of these dopamine circuits. Both ADHD and obesity are usually associated with reduced volume of putamen, known to be a fundamental player in inhibitory control functioning. Human and animal studies have also demonstrated that obese individuals have decreased dopamine D2 receptor availability in the striatum. Recently genetic analyses implicated specifically Dopamine-DARPP32 Feedback in cAMP Signaling in both ADHD and Obesity. Conclusions ADHD and obesity are often comorbid. Dysregulated dopaminergic neurotransmission seems to be a fundamental factor underlying the overlap between ADHD and obesity, probably involving DARPP-32 signaling and possibly through neurobiological features of putamen, namely inhibitory control. Further studies are necessary to explain the neurobiological correlation between these entities.

The majority of morphological abnormalities reported for elasmobranchs are cases of bicephalia. This contribution describes the third confirmed case worldwide and the first in the South Atlantic of diprosopus tetrophthalmus (craniofacial duplication) in a foetus of blue shark, Prionace glauca (Linnaeus, 1758), from a female caught off the Brazilian coast (26°36′11′′S, 45°56′00′′W) in July 2007. The specimen is described and compared to normal specimens from the same size and to another one with similar deformities from Chile. The embryo is smaller than a normal embryo, with deformities in the skull, head muscles and curvature of the vertebral column.