Intermittency and the Value of Renewable Energy

A key problem with renewable energy is intermittency. This paper develops a method to quantify the social costs of large-scale renewable energy generation. The method is based on a theoretical model of electricity system operations that allows for endogenous choices of generation capacity investment, reserve operations, and demand-side management. We estimate the model using generator characteristics, solar output, electricity demand, and weather forecasts for an electric utility in southeastern Arizona. The estimated welfare loss associated with a 20% solar photovoltaic mandate is 11% higher than the average cost difference between solar generation and natural gas generation. Unforecastable intermittency yields welfare loss equal to 3% of the average cost of solar. Eliminating a mandate provision requiring a minimum percentage of distributed solar generation increases welfare. With a $21/ton social cost of CO2 this mandate is welfare neutral if solar capacity costs decrease by 65%.

O envolvimento dos alótipos de C4 na patogênese das doenças humanas

The complement system is an important humoral defense mechanism that plays a relevant role against microbial agents, inflammatory response control, and immunocomplex clearance. Classical complement pathway activation is antibody-dependent. The C4 component participates in the initial step of activation, and C4 expression is determined by 2 pairs of allotypes: C4A and C4B. Deficiencies in C4 allotypes have been associated with several diseases. The aim of the present review is evaluate the reported data in the literature regarding specific C4A and C4B deficiencies and characterize their clinical relevance. We searched the MEDLINE and LILACS databases. Papers referring to total C4 deficiency without allotype evaluation and case reports of primary C4 deficiency were not included. Deficiencies in C4 allotypes have been associated with Mycobacterium leprae infection, erythema nodosum, systemic sclerosis with anti-topoisomerase I antibodies, intermediate congenital adrenal hyperplasia with DR5 genotype, diabetes mellitus type 1 with DR3,4 genotype, and diabetes mellitus with antibodies against islet cells. C4 allotype deficiency is also related to C4B deficiency and autoimmune-associated diseases, such as systemic lupus erythematosus, or diseases with an autoimmune component, such as autism. Some reports associate C4A with thyroiditis after delivery as well as limited and systemic sclerosis without anti-topoisomerase I antibodies. However, the studies with C4A and C4B have been concentrated in isolated populations, and some of the studies could not be reproduced by other authors.O sistema complemento constitui um importante sistema de defesa humoral, exercendo papel relevante na resposta contra agentes microbianos, no controle da resposta inflamatória e na depuração de imunocomplexos. A ativação da via clássica é dependente da formação do complexo antígeno-anticorpo. O componente C4 do complemento participa da etapa inicial de ativação desta via e a sua expressão é determinada por dois alótipos : C4A e C4B. A deficiência dos alótipos de C4 tem sido relacionada a várias doenças. O objetivo do presente estudo foi avaliar os dados de literatura que descrevem as deficiências específicas de C4A e C4B com a finalidade de caracterizar seu significado clínico. Foi realizada uma ampla revisão bibliográfica através do MEDLINE e LILACS, avaliando-se os dados de literatura. Excluiu-se estudos com a avaliação de C4 total sem a análise dos alótipos e relatos de caso isolados de deficiência total de C4. Verificou-se que a deficiência dos alótipos de C4 está relacionada com algumas doenças: hanseníase, esclerose sistêmica com anticorpos anti-topoisomerase I, hiperplasia adrenal congênita intermediária com genótipo DR5, diabetes mellitus tipo 1 com genótipo DR3,4 e diabetes mellitus tipo 1 com anticorpos anti-células das ilhotas. Também foram observadas algumas associações entre C4B e doenças auto-imunes como lupus eritematoso sistêmico, ou que se supõe terem um componente auto-imune como o autismo. Estudos demonstraram associações do C4A com tireoidite pós-parto, esclerose limitada e esclerose sistêmica sem anticorpos anti-topoisomerase I. Porém, os estudos dos alótipos de C4 se concentraram em populações isoladas e alguns destes não conseguiram ser reproduzidos por outros autores

Synthesis of Nitrogenated Heterocycles by Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)haloimines

Highly optically enriched, protected, nitrogenated heterocycles with different ring sizes have been synthesized by a very efficient methodology consisting of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)haloimines followed by treatment with a base to promote an intramolecular nucleophilic substitution process. N-Protected aziridines, pyrrolidines, piperidines, and azepanes bearing aromatic, heteroaromatic, and aliphatic substituents have been obtained in very high yields and diastereomeric ratios up to >99:1. The free heterocycles can be easily obtained by a simple and mild desulfinylation procedure. Both enantiomers of the free heterocycles can be prepared with the same good results by changing the absolute configuration of the sulfur atom of the sulfinyl group.This work was generously supported by the Spanish Ministerio de Ciencia e Innovación (MICINN; grant no. CONSOLIDER INGENIO 2010, CSD2007-00006, CTQ2007-65218 and CTQ2011-24151) and the Generalitat Valenciana (PROMETEO/2009/039 and FEDER). O.P. thanks the Spanish Ministerio de Educación for a predoctoral fellowship (grant no. AP-2008-00989)

Clinical features of patients with homozygous complement C4A or C4B deficiency

Introduction Homozygous deficiencies of complement C4A or C4B are detected in 1-10% of populations. In genome-wide association studies C4 deficiencies are missed because the genetic variation of C4 is complex. There are no studies where the clinical presentation of these patients is analyzed. This study was aimed to characterize the clinical features of patients with homozygous C4A or C4B deficiency. Material and methods Thirty-two patients with no functional C4A, 87 patients with no C4B and 120 with normal amount of C4 genes were included. C4A and C4B numbers were assessed with genomic quantitative real-time PCR. Medical history was studied retrospectively from patients' files. Results Novel associations between homozygous C4A deficiency and lymphoma, coeliac disease and sarcoidosis were detected. These conditions were present in 12.5%, (4/32 in patients vs. 0.8%, 1/120, in controls, OR = 17.00, 95%Cl = 1.83-158.04, p = 0.007), 12.5% (4/32 in patients vs. 0%, 0/120 in controls, OR = 1.14, 95%Cl = 1.00-1.30, p = 0.002) and 12.5%, respectively (4/32 in patients vs. 2.5%, 3/120 in controls, OR = 5.571, 95%Cl = 1.79-2.32, p = 0.036). In addition, C4A and C4B deficiencies were both associated with adverse drug reactions leading to drug discontinuation (34.4%, 11/32 in C4A-deficient patients vs. 14.2%, 17/120 in controls, OR = 3.174, 95%Cl = 1.30-7.74, p = 0.009 and 28.7%, 25/87 in C4B-deficient patients, OR = 2.44, 95%Cl = 1.22-4.88, p = 0.010). Conclusion This reported cohort of homozygous deficiencies of C4A or C4B suggests that C4 deficiencies may have various unrecorded disease associations. C4 gene should be considered as a candidate gene in studying these selected disease associations.Peer reviewe