RESUMEN
Wildfires, exacerbated by extreme weather events and land use, threaten to change the Amazon from a net carbon sink to a net carbon source. Here, we develop and apply a coupled ecosystem-fire model to quantify how greenhouse gas-driven drying and warming would affect wildfires and associated CO2 emissions in the southern Brazilian Amazon. Regional climate projections suggest that Amazon fire regimes will intensify under both low- and high-emission scenarios. Our results indicate that projected climatic changes will double the area burned by wildfires, affecting up to 16% of the region's forests by 2050. Although these fires could emit as much as 17.0 Pg of CO2 equivalent to the atmosphere, avoiding new deforestation could cut total net fire emissions in half and help prevent fires from escaping into protected areas and indigenous lands. Aggressive efforts to eliminate ignition sources and suppress wildfires will be critical to conserve southern Amazon forests.
Asunto(s)
Incendios , Bosques , Brasil , Simulación por Computador , Conservación de los Recursos Naturales , Geografía , Modelos Teóricos , Estaciones del AñoRESUMEN
Psoriasis is an autoimmune disease associated with the production of pro-inflammatory cytokines. The identification of these molecules in the pathogenesis of psoriasis facilitated the use of monoclonal antibodies to block their actions as a treatment for severe psoriasis. An increased inflammatory response has been documented in patients with obesity, a condition that is associated with the occurrence and severity of psoriasis. Osteopontin (OPN), TNF and CXCL9 levels are enhanced in patients with psoriasis, although OPN has been documented in the adipose tissue of obese patients without psoriasis. The prevalence of obesity is much higher in psoriasis patients compared with the general population. Thus, we aimed to evaluate the relationship between cytokine levels and psoriasis in the context of obesity. We compared OPN and CXCL9 plasma levels among 117 psoriasis patients and 27 healthy body mass index-matched subjects using ELISA. We also analyzed the TNF, CCL2 and CCL5 levels in a smaller subgroup of patients and matched controls. Median OPN, CCL5 and CXCL9 levels were significantly higher in psoriasis patients compared with the controls, independent of obesity. There was no difference between the median CCL2 levels in the psoriasis patients and the controls (P<0.05), although the CCL2 levels were elevated in obese patients compared with non-obese psoriasis patients (P<0.001). Facial involvement and the psoriasis area severity index (PASI) score were not associated (P<0.05) with OPN levels or elevated levels of chemokines. There was no significant correlation between the OPN and CXCL9 levels or the OPN and TNF levels in psoriasis patients. This work confirms that OPN, CCL5 and CXCL9 plasma levels are higher in psoriasis patients and provides evidence that their higher levels are not a consequence of obesity. Furthermore, the results demonstrate that OPN production is independent of TNF-α and CXCL9.
Asunto(s)
Quimiocina CCL5/sangre , Quimiocina CXCL9/sangre , Obesidad/sangre , Osteopontina/sangre , Psoriasis/sangre , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Psoriasis/complicacionesRESUMEN
Infant formula samples were analysed to determine their free L-carnitine content by using flow injection (FI) with an incorporated immobilised carnitine acetyltransferase bioreactor. The methodology was based on the spectrophotometric determination through its reaction with carnitine acetyltransferase coupled with acetyl coenzyme A (acetyl-CoA) and dithiobenzoate. The merging zones technique was used to minimise acetyl CoA consumption. Linearity was observed over the concentration range 10-80 mg l-1 with L-carnitine as standard (r = 0.9998) and the rate of analysis was 50 h-1 infant formula samples. The enzymic FI method afforded a low RSD (2.2%). Comparisons were made with other methods of known accuracy. The enzymic reactors were stable for 3 months when used daily at the optimum pH.