RESUMO
Sustained human pressures on the environment have significantly increased the frequency, extent, and severity of wildfires, globally. This is particularly the case in Mediterranean regions, in which human-caused wildfires represent up to 90% of all recorded wildfire ignitions. In Chile, it has been estimated that nearly 90% of wildfires are related to human activities, and that their frequency and distribution have steadily increased over the last decade. Despite this, the role of socio-economic factors in driving wildfire activity and its spatiotemporal distribution remains unclear. In this study, we assess the association between socio-economic drivers and spatiotemporal patterns of wildfires in the Mediterranean region of south-central Chile over the period 2010-2018. Our results show that 98.5% of wildfires are related to human activities, either accidentally (58.2%) or intentionally (36.6%). Wildfires occurred primarily during the summer months and their density at the commune-level was associated with increased road access, as well as with the percentage of land covered by agriculture, exotic tree plantations, and native forest. Wildfire activity at the commune-level was also related to socio-economic variables such as population density, proportion of indigenous population, and unemployment rate, although such associations varied considerably depending on the region and on whether the wildfire was started accidentally or intentionally. Our study provides a comprehensive and interdisciplinary assessment of the complex ways in which land-cover and socio-economic factors drive the distribution of wildfire activity in south-central Chile. It represents an important guide for policy-making, as well a baseline for research into strategies aimed at predicting and mitigating wildfire activity at both local and national levels.
Assuntos
Incêndios Florestais , Chile , Atividades Humanas , Humanos , Região do Mediterrâneo , Fatores SocioeconômicosRESUMO
In order to ensure the provision of goods and services from forests, many governments have promoted less-traditional conservation initiatives such as programs of payments for ecosystem services called, more broadly, direct payments for conservation. The Socio Bosque Program (SBP) is a governmental program in Ecuador that directly provides economic incentives to rural families and local and indigenous communities who have voluntarily agreed to comply with some conservation activities. An impact evaluation method (matching) was used to assess the impact of the SBP between 2008 and 2014. This study revealed that on average, the SBP reduced deforestation by 1.5% in those forests that received the SBP's direct payment. These forests would have been deforested if the SBP had not been implemented. Assessment of the impact of the SBP on individual and collective contracts, using the matching method, revealed that 3.4% and roughly 1% of the forest would have been deforested in the absence of the program, respectively. In other words, the protected area in the collective SBP was 1,247,500 ha and, if the SBP had not been implemented, an area of 11,227 ha would have been lost between 2008 and 2014. The 165,700 ha protected by the individual SBP, it was estimated that 5,733 ha were not deforested due to the implementation of the conservation program. Conventional estimates of the impact of the SBP tend to overestimate avoided deforestation because they do not control for observable covariates that correlate with or affect both SBP participation and deforestation. The conclusions are robust, even given potential hidden biases. The present study demonstrated that the SBP serves to mitigate the effects of climate change, especially with those contracts that are intended for individual owners.
Assuntos
Conservação dos Recursos Naturais , Florestas , Ecossistema , GovernoRESUMO
Most evaluations of the effectiveness of PAs have relied on indirect estimates based on comparisons between protected and unprotected areas. Such methods can be biased when protection is not randomly assigned. We add to the growing literature on the impact of PAs by answering the following research questions: What is the impact of Chilean PAs on deforestation which occurred between 1986 and 2011? How do estimates of the impact of PAs vary when using only public land as control units? We show that the characteristics of the areas in which protected and unprotected lands are located differ significantly. To satisfactorily estimate the effects of PAs, we use matching methods to define adequate control groups, but not as in previous research. We construct control groups using separately non-protected private areas and non-protected public lands. We find that PAs avoid deforestation when using unprotected private lands as valid controls, however results show no impact when the control group is based only on unprotected public land. Different land management regimes, and higher levels of enforcement inside public lands may reduce the opportunity to add additional conservation benefits when the national systems for PAs are based on the protection of previously unprotected public lands. Given that not all PAs are established to avoid deforestation, results also admit the potential for future studies to include other outcomes including forest degradation (not just deforestation), biodiversity, wildlife, primary forests (not forests in general), among others.
Assuntos
Conservação dos Recursos Naturais , Recursos Naturais/provisão & distribuição , Análise de Variância , ChileRESUMO
Supply of international environmental public goods must meet certain conditions to be socially efficient, and several reasons explain why they are currently undersupplied. Diagnosis of the public goods failure associated with particular ecosystem services is critical to the development of the appropriate international response. There are two categories of international environmental public goods that are most likely to be undersupplied. One has an additive supply technology and the other has a weakest link supply technology. The degree to which the collective response should be targeted depends on the importance of supply from any one country. In principle, the solution for the undersupply lies in payments designed to compensate local providers for the additional costs they incur in meeting global demand. Targeted support may take the form of direct investment in supply (the Global Environment Facility model) or of payments for the benefits of supply (the Payments for Ecosystem Services model).
Assuntos
Comércio , Compensação e Reparação , Meio Ambiente , Internacionalidade , EcossistemaRESUMO
BACKGROUND: On the basis of a previous meta-analysis, the International Adjuvant Lung Cancer Trial was designed to evaluate the effect of cisplatin-based adjuvant chemotherapy on survival after complete resection of non-small-cell lung cancer. METHODS: We randomly assigned patients either to three or four cycles of cisplatin-based chemotherapy or to observation. Before randomization, each center determined the pathological stages to include, its policy for chemotherapy (the dose of cisplatin and the drug to be combined with cisplatin), and its postoperative radiotherapy policy. The main end point was overall survival. RESULTS: A total of 1867 patients underwent randomization; 36.5 percent had pathological stage I disease, 24.2 percent stage II, and 39.3 percent stage III. The drug allocated with cisplatin was etoposide in 56.5 percent of patients, vinorelbine in 26.8 percent, vinblastine in 11.0 percent, and vindesine in 5.8 percent. Of the 932 patients assigned to chemotherapy, 73.8 percent received at least 240 mg of cisplatin per square meter of body-surface area. The median duration of follow-up was 56 months. Patients assigned to chemotherapy had a significantly higher survival rate than those assigned to observation (44.5 percent vs. 40.4 percent at five years [469 deaths vs. 504]; hazard ratio for death, 0.86; 95 percent confidence interval, 0.76 to 0.98; P<0.03). Patients assigned to chemotherapy also had a significantly higher disease-free survival rate than those assigned to observation (39.4 percent vs. 34.3 percent at five years [518 events vs. 577]; hazard ratio, 0.83; 95 percent confidence interval, 0.74 to 0.94; P<0.003). There were no significant interactions with prespecified factors. Seven patients (0.8 percent) died of chemotherapy-induced toxic effects. CONCLUSIONS: Cisplatin-based adjuvant chemotherapy improves survival among patients with completely resected non-small-cell lung cancer.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Vimblastina/análogos & derivados , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Quimioterapia Adjuvante , Cisplatino/efeitos adversos , Intervalo Livre de Doença , Etoposídeo/administração & dosagem , Humanos , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/cirurgia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Taxa de Sobrevida , Vimblastina/administração & dosagem , Vindesina/administração & dosagem , VinorelbinaRESUMO
Even if postoperative thoracic radiotherapy has been widely used as adjuvant treatment, the oncological community has poorly evaluated this treatment after complete surgical resection in lung cancer. The number of patients included in randomised trials has been less than 3000. The analysis of these trials showed rather a deleterious effect in terms of overall survival, suggesting a lethal late treatment-related toxicity in early stage I or II disease. In N2 disease, these effects have not been demonstrated but information is lacking to consider this treatment on an evidence-based medicine policy. We discuss here the available worldwide information on this subject. There is an urgent need for new trials in this topic.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/cirurgia , Metástase Linfática/radioterapia , Carcinoma Pulmonar de Células não Pequenas/patologia , Humanos , Neoplasias Pulmonares/patologia , Estadiamento de Neoplasias , Prognóstico , Radioterapia Adjuvante , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Análise de SobrevidaRESUMO
Purpose. To correlate axillary Technetium-99m-sestamibi uptake with the axillary histology in patients with proven breast cancer. Secondly, to correlate the breast scintimammography results with the tumor histology. Materials and methods. Fifty-one patients with operable breast cancer T1, T2 or T3 and N0 or N1 had a scintimammography before surgery. Images were interpreted directly from the computer screen by two specialists who did not have knowledge about clinical or radiological information concerning the patients. Surgical treatment included conservative surgery or mastectomy, both followed by axillary dissection for malignant tumors (45 patients) and only excision for benign lesions (6 patients). Statistical analysis correlated scintimammography and histologic results. Results. The sensitivity and specificity of Tc99m-sestamibi to assess histologic lymph node involvement in patients with operable breast cancer was 35 percent (95 percent CI:14-61 percent) and 57 percent (95 percent CI:37-75 percent) respectively. The positive predictive value was 33 percent (95 percent CI:13-58 percent) and the negative predictive value was 59 percent ( 95 percent CI: 38-77 percent). The sensitivity and specificity of Tc99-sestamibi to assess breast tumor malignancy was 97 percent (95 percent CI:88-99 percent) and 33 percent (95 percent CI: 4-77 percent) respectively, calculated in only six patients. The positive predictive value was 91 percent (95 percent CI: 80-97 percent) and the negative predictive value was 66 percent (95 percent CI:9-99 percent). Conclusion. Our findings regarding the preoperative axillary assessment with Tc99m-sestamibi do not support the use of this imaging modality for this purpose
Assuntos
Humanos , Feminino , Neoplasias da Mama , Metástase Linfática/patologia , Axila , Mamografia , Cintilografia , Tecnécio Tc 99m Sestamibi , Linfonodos/patologiaRESUMO
Prophylatic cranial irradiation (PCI) in patients with small cell lung cancer (SCLC) is a treatment under evaluation for about 30 years. Since the first randomized trials, it was clear that its use significantly decreased the brain metastasis rate. However, its effect on overall survival was not demonstrated. Retrospective reviews suggested that PCI could induce late neurologic damage. In recent years, two large randomized trials did not confirm this deleterious effect and even suggested a beneficial effect on survival. A recent meta-analysis including almost 1,000 randomized patients confirmed an improvement in overall survival. We discuss here the different aspects of this preventive treatment in a potentially curable disease.