Robust Amazon precipitation projections in climate models that capture realistic land–atmosphere interactions

Land–atmosphere interactions have an important influence on Amazon precipitation (P), but evaluation of these processes in climate models has so far been limited. We analysed relationships between Amazon P and evapotranspiration (ET) in the 5th Coupled Model Intercomparison Project models to evaluate controls on surface moisture fluxes and assess the credibility of regional P projections. We found that only 13 out of 38 models captured an energy limitation on Amazon ET, in agreement with observations, while 20 models instead showed Amazon ET is limited by water availability. Models that misrepresented controls on ET over the historical period projected both large increases and decreases in Amazon P by 2100, likely amplified by unrealistic land–atmosphere interactions. In contrast, large future changes in annual and seasonal-scale Amazon P were suppressed in models that simulated realistic controls on ET, due to modulating land–atmosphere interactions. By discounting projections from models that simulated unrealistic ET controls, our analysis halved uncertainty in basin-wide future P change. The ensemble mean of plausible models showed a robust drying signal over the eastern Amazon and in the dry season, and P increases in the west. Finally, we showed that factors controlling Amazon ET evolve over time in realistic models, reducing climate stability and leaving the region vulnerable to further change

The effects of social determinants of health on acquired immune deficiency syndrome in a low-income population of Brazil: a retrospective cohort study of 28.3 million individuals.

BACKGROUND: Social determinants of health (SDH) include factors such as income, education, and race, that could significantly affect the human immunodeficiency virus and acquired immunodeficiency syndrome (HIV/AIDS). Studies on the effects of SDH on HIV/AIDS are limited, and do not yet provide a systematic understanding of how the various SDH act on important indicators of HIV/AIDS progression. We aimed to evaluate the effects of SDH on AIDS morbidity and mortality. METHODS: A retrospective cohort of 28.3 million individuals was evaluated over a 9-year period (from 2007 to 2015). Multivariable Poisson regression, with a hierarchical approach, was used to estimate the effects of SDH-at the individual and familial level-on AIDS incidence, mortality, and case-fatality rates. FINDINGS: A total of 28,318,532 individuals, representing the low-income Brazilian population, were assessed, who had a mean age of 36.18 (SD: 16.96) years, 52.69% (14,920,049) were female, 57.52% (15,360,569) were pardos, 34.13% (9,113,222) were white/Asian, 7.77% (2,075,977) were black, and 0.58% (154,146) were indigenous. Specific socioeconomic, household, and geographic factors were significantly associated with AIDS-related outcomes. Less wealth was strongly associated with a higher AIDS incidence (rate ratios-RR: 1.55; 95% confidence interval-CI: 1.43-1.68) and mortality (RR: 1.99; 95% CI: 1.70-2.34). Lower educational attainment was also greatly associated with higher AIDS incidence (RR: 1.46; 95% CI: 1.26-1.68), mortality (RR: 2.76; 95% CI: 1.99-3.82) and case-fatality rates (RR: 2.30; 95% CI: 1.31-4.01). Being black was associated with a higher AIDS incidence (RR: 1.53; 95% CI: 1.45-1.61), mortality (RR: 1.69; 95% CI: 1.57-1.83) and case-fatality rates (RR: 1.16; 95% CI: 1.03-1.32). Overall, also considering the other SDH, individuals experiencing greater levels of socioeconomic deprivation were, by far, more likely to acquire AIDS, and to die from it. INTERPRETATION: In the population studied, SDH related to poverty and social vulnerability are strongly associated with a higher burden of HIV/AIDS, most notably less wealth, illiteracy, and being black. In the absence of relevant social protection policies, the current worldwide increase in poverty and inequalities-due to the consequences of the COVID-19 pandemic, and the effects of war in the Ukraine-could reverse progress made in the fight against HIV/AIDS in low- and middle-income countries (LMIC). FUNDING: National Institute of Allergy and Infectious Diseases (NAIDS), National Institutes of Health (NIH), US Grant Number: 1R01AI152938

Reaction of rat connective tissue to mineral trioxide aggregate and diaket

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to compare the reaction of rat connective tissue to two root-end filling materials: white Mineral Trioxide Aggregate (WMTA) and Diaket.</p> <p>Methods</p> <p>Each of the materials was placed in dentine tubes and implanted subcutaneously in the dorsal connective tissue of 21 Wistar albino rats. Tissue biopsies were collected 7, 30, and 60 days after the implantation procedure. The specimens were processed and stained with hematoxylin and eosin and examined microscopically. After determining inflammatory cell numbers in sections from each specimen, inflammatory reaction scores were defined as follows: 0; no or few inflammatory cells (no reaction), 1; less than 25 cells (mild reaction), 2; 25 to 125 cells, (moderate reaction), and 3; 125 or more cells (severe reaction). Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney tests.</p> <p>Results</p> <p>There were statistically significant differences in the median inflammatory cell numbers throughout the three test periods, with the most severe degree of inflammation observed at the one-week period. Few cases of necrosis were observed with WMTA. Diaket exhibited the most severe degree of inflammation and necrosis. After 30 days, both materials provoked moderate inflammatory reaction. The eight-week period showed the least severe degree of inflammation in all groups.</p> <p>Conclusions</p> <p>It was concluded that WMTA exhibits a more favourable tissue response compared with Diaket which induced more severe inflammatory reaction than WMTA and the control.</p

Cryptosporidium parvum, a potential cause of colic adenocarcinoma

<p>Abstract</p> <p>Background</p> <p>Cryptosporidiosis represents a major public health problem. This infection has been reported worldwide as a frequent cause of diarrhoea. Particularly, it remains a clinically significant opportunistic infection among immunocompromised patients, causing potentially life-threatening diarrhoea in HIV-infected persons. However, the understanding about different aspects of this infection such as invasion, transmission and pathogenesis is problematic. Additionally, it has been difficult to find suitable animal models for propagation of this parasite. Efforts are needed to develop reproducible animal models allowing both the routine passage of different species and approaching unclear aspects of <it>Cryptosporidium </it>infection, especially in the pathophysiology field.</p> <p>Results</p> <p>We developed a model using adult severe combined immunodeficiency (SCID) mice inoculated with <it>Cryptosporidium parvum </it>or <it>Cryptosporidium muris </it>while treated or not with Dexamethasone (Dex) in order to investigate divergences in prepatent period, oocyst shedding or clinical and histopathological manifestations. <it>C. muris</it>-infected mice showed high levels of oocysts excretion, whatever the chemical immunosuppression status. Pre-patent periods were 11 days and 9.7 days in average in Dex treated and untreated mice, respectively. Parasite infection was restricted to the stomach, and had a clear preferential colonization for fundic area in both groups. Among <it>C. parvum</it>-infected mice, Dex-treated SCID mice became chronic shedders with a prepatent period of 6.2 days in average. <it>C. parvum</it>-inoculated mice treated with Dex developed glandular cystic polyps with areas of intraepithelial neoplasia, and also with the presence of intramucosal adenocarcinoma.</p> <p>Conclusion</p> <p>For the first time <it>C. parvum </it>is associated with the formation of polyps and adenocarcinoma lesions in the gut of Dex-treated SCID mice. Additionally, we have developed a model to compare chronic <it>muris </it>and <it>parvum </it>cryptosporidiosis using SCID mice treated with corticoids. This reproducible model has facilitated the evaluation of clinical signs, oocyst shedding, location of the infection, pathogenicity, and histopathological changes in the gastrointestinal tract, indicating divergent effects of Dex according to <it>Cryptosporidium </it>species causing infection.</p