ABSTRACT
The Amazon rainforests have been undergoing unprecedented levels of human-induced disturbances. In addition to local impacts, such changes are likely to cascade following the eastern-western atmospheric flow generated by trade winds. We propose a model of spatial and temporal interactions created by this flow to estimate the spread of effects from local disturbances to downwind locations along atmospheric trajectories. The spatial component captures cascading effects propagated by neighboring regions, while the temporal component captures the persistence of local disturbances. Importantly, all these network effects can be described by a single matrix, acting as a spatial multiplier that amplifies local forest disturbances. This matrix holds practical implications for policymakers as they can use it to easily map where the damage of an initial forest disturbance is amplified and propagated to. We identify regions that are likely to cause the largest impact throughout the basin and those that are the most vulnerable to shocks caused by remote deforestation. On average, the presence of cascading effects mediated by winds in the Amazon doubles the impact of an initial damage. However, there is heterogeneity in this impact. While damage in some regions does not propagate, in others, amplification can reach 250%. Since we only account for spillovers mediated by winds, our multiplier of 2 should be seen as a lower bound.
Subject(s)
Conservation of Natural Resources , Forests , Humans , Rainforest , WindABSTRACT
Abstract Susceptibility to cancer ensues in individuals carrying malfunctioning DNA repair mechanisms. The impact of Single Nucleotide Polymorphisms (SNPs) in key DNA repair mechanisms on risk for prostate cancer was investigated in this case-control study. Samples consisted of 110 patients with confirmed prostate cancer and 200 unaffected men, from Rio de Janeiro, Brazil. XPD/Lys751Gln (rs13181), APEX1/Asp148Glu (rs1130409), and RAD51/G135C (rs1801320) SNPs were analyzed by PCR-RFLP. Allelic and genotypic frequencies were calculated and compared by Chi-Square test. The association between SNPs and clinical/epidemiological data was considered significant by Odds Ratio analysis, with IC95% and a p-value≤0.05. Only the XPD/Lys751Gln SNP significantly increased susceptibility to disease in southeastern Brazilian men, with p≤0.001 [OR=2.36 (1.46-3.84)], with no association with APEX1 or RAD51 SNPs. Combined XPD+RAD51 SNPs were highly associated with the disease, p≤0.005 [OR=3.40 (1.32-9.20)]. A Chi-Square significant association between XPD/Lys751Gln and Gleason score was also observed (OR=9.31; IC95%=1.19-428.0; p=0.022). Epidemiological inquiries revealed that exposure to pesticides significantly impacted the risk for prostate cancer in this population. DNA repair dysfunctions seem to prevail among workers exposed to chemical byproducts to cancer in this specific tissue. Non-invasive genotyping SNPs may help assessment of prostate cancer risk in environmentally exposed populations.
ABSTRACT
Susceptibility to cancer ensues in individuals carrying malfunctioning DNA repair mechanisms. The impact of Single Nucleotide Polymorphisms (SNPs) in key DNA repair mechanisms on risk for prostate cancer was investigated in this case-control study. Samples consisted of 110 patients with confirmed prostate cancer and 200 unaffected men, from Rio de Janeiro, Brazil. XPD/Lys751Gln (rs13181), APEX1/Asp148Glu (rs1130409), and RAD51/G135C (rs1801320) SNPs were analyzed by PCR-RFLP. Allelic and genotypic frequencies were calculated and compared by Chi-Square test. The association between SNPs and clinical/epidemiological data was considered significant by Odds Ratio analysis, with IC95% and a p-value≤0.05. Only the XPD/Lys751Gln SNP significantly increased susceptibility to disease in southeastern Brazilian men, with p≤0.001 [OR=2.36 (1.46-3.84)], with no association with APEX1 or RAD51 SNPs. Combined XPD+RAD51 SNPs were highly associated with the disease, p≤0.005 [OR=3.40 (1.32-9.20)]. A Chi-Square significant association between XPD/Lys751Gln and Gleason score was also observed (OR=9.31; IC95%=1.19-428.0; p=0.022). Epidemiological inquiries revealed that exposure to pesticides significantly impacted the risk for prostate cancer in this population. DNA repair dysfunctions seem to prevail among workers exposed to chemical byproducts to cancer in this specific tissue. Non-invasive genotyping SNPs may help assessment of prostate cancer risk in environmentally exposed populations.
ABSTRACT
We consider an evolution non-local free boundary problem that arises in the modelling of speculative bubbles. The solution of the model is the speculative component in the price of an asset. In the framework of viscosity solutions, we show the existence and uniqueness of the solution. We also show that the solution is convex in space, and establish several monotonicity properties of the solution and of the free boundary with respect to parameters of the problem. To study the free boundary, we use, in particular, the fact that the odd part of the solution solves a more standard obstacle problem. We show that the free boundary is [Formula: see text] and describe the asymptotics of the free boundary as c, the cost of transacting the asset, goes to zero.
ABSTRACT
Recursive utility models that feature investor concerns about the intertemporal composition of risk are used extensively in applied research in macroeconomics and asset pricing. These models represent preferences as the solution to a nonlinear forward-looking difference equation with a terminal condition. In this paper we study infinite-horizon specifications of this difference equation in the context of a Markov environment. We establish a connection between the solution to this equation and to an arguably simpler Perron-Frobenius eigenvalue equation of the type that occurs in the study of large deviations for Markov processes. By exploiting this connection, we establish existence and uniqueness results. Moreover, we explore a substantive link between large deviation bounds for tail events for stochastic consumption growth and preferences induced by recursive utility.
Subject(s)
Economic Development/statistics & numerical data , Markov Chains , Models, Econometric , Humans , Risk Assessment , Stochastic ProcessesABSTRACT
Este ensaio clinico prospectivo consistiu na observacao de 30 pacientes portadores de infeccao urinaria aguda, de instalacao recente, na maioria dos casos cistites e uretrites. O criterio de inclusao foi baseado principalmente no quadro sintomatologico, independentemente do resultado das uroculturas. Pacientes de ambos os sexos foram tratados ambulatorialmente com acido pipemidico, um derivado quinolonico em dose unica de 1.600 mg por via oral. Obtivemos a remissao dos sintomas na maioria dos casos tratados, isto e, em 27 pacientes (90%), independentemente do resultado da cultura pre ou pos-medicacao. Concluimos que o tratamento com o acido pipemicico e eficaz nos casos agudos incipientes de infeccao urinaria
Subject(s)
Adolescent , Adult , Middle Aged , Humans , Male , Female , Nicotinic Acids , Urinary Tract InfectionsABSTRACT
Os autores mostram a dificuldade de diagnóstico do angiomiolipoma renal em dois casos, nos quais o tumor näo manifesta quadro clínico próprio, mas adota a sintomatologia geral de qualquer massa expansiva renal. É ressaltada também a associaçäo deste tumor com a esclerose tuberosa de Bourneville
Subject(s)
Middle Aged , Humans , Female , Kidney Neoplasms/complications , Kidney Neoplasms/diagnosis , Lipoma/complications , Lipoma/diagnosis , Tuberous Sclerosis/complications , BrazilABSTRACT
Os autores abordam aspectos gerais da patologia, analisando os casos reportados segundo as observaçöes clínicas, anatomopatológicas, laboratoriais e radiológicas referentes a esta entidade. Säo apresentados três casos, ressaltando os autores a dificuldade de diagnóstico, devido à inespecificidade dos exames clínicos, laboratoriais e radiológicos
