Modeling and forecasting municipal solid waste generation in the US energy supply

This paper describes an economic and statistical approach to modeling and forecasting municipal solid waste generation in the US energy supply. It begins with a discussion of the historical developments in the waste to energy industry over the last 25 years. Then a model is developed to provide energy policy makers with an analytical framework for understanding the relationships between the solid waste industry and the waste to energy industry. The model is tested empirically using data at the national level. The model's forecasts are compared with projections made by the US Environmental Protection Agency     

ATM damage response and XLF repair factor are functionally redundant in joining DNA breaks

Classical non-homologous DNA end-joining (NHEJ) is a major mammalian DNA double-strand-break (DSB) repair pathway. Deficiencies for classical NHEJ factors, such as XRCC4, abrogate lymphocyte development, owing to a strict requirement for classical NHEJ to join V(D)J recombination DSB intermediates. The XRCC4-like factor (XLF; also called NHEJ1) is mutated in certain immunodeficient human patients and has been implicated in classical NHEJ; however, XLF-deficient mice have relatively normal lymphocyte development and their lymphocytes support normal V(D)J recombination. The ataxia telangiectasia-mutated protein (ATM) detects DSBs and activates DSB responses by phosphorylating substrates including histone H2AX. However, ATM deficiency causes only modest V(D)J recombination and lymphocyte developmental defects, and H2AX deficiency does not have a measurable impact on these processes. Here we show that XLF, ATM and H2AX all have fundamental roles in processing and joining DNA ends during V(D)J recombination, but that these roles have been masked by unanticipated functional redundancies. Thus, combined deficiency of ATM and XLF nearly blocks mouse lymphocyte development due to an inability to process and join chromosomal V(D)J recombination DSB intermediates. Combined XLF and ATM deficiency also severely impairs classical NHEJ, but not alternative end-joining, during IgH class switch recombination. Redundant ATM and XLF functions in classical NHEJ are mediated by ATM kinase activity and are not required for extra-chromosomal V(D)J recombination, indicating a role for chromatin-associated ATM substrates. Correspondingly, conditional H2AX inactivation in XLF-deficient pro-B lines leads to V(D)J recombination defects associated with marked degradation of unjoined V(D)J ends, revealing that H2AX has a role in this process.     

William Hasledine Pepys FRS: A Life in Scientific Research,Learned Societies and Technical Enterprise

In a long and many-sided career, William Hasledine Pepys (1775-1856) contributed significantly to the advancement of the chemical and physical sciences during the first half of the nineteenth century. As an original investigator he determined, in collaboration with William Allen, the composition of carbon dioxide, and the density of ammonia, and elucidated the chemical phenomena of respiration in man, animals, and plants. The success of these researches was largely due to the use of ingenious apparatus of his own invention and design. In the field of experimental physics, he investigated several aspects of the recently discovered Voltaic electricity: his 'Voltaic coil', consisting of only two plates, but of very large dimensions, was particularly suited for investigating electromagnetic phenomena and was so used in Davy's researches. Pepys was one of the co-founders of the Mineralogical and Geological Societies, and was elected a Fellow of the Royal Society in 1808. As a prominent member of both the Royal and London Institutions, he held honorary office as Manager and Vice-President, contributing materially to the direction of the affairs of these bodies. Pepys was a friend of Humphry Davy and was acquainted with nearly all the leading scientists and medical men of the day. At the same time, he superintended a notable manufacture of surgical instruments in the City, and promoted by his active directorship the affairs of two public companies, both pioneers in their technological fields, namely the Imperial Continental Gas Association, which was active in introducing the new gas illumination to cities and towns across Europe, and the General Steam Navigation Company, which first maintained a regular passenger and cargo service to Continental ports by the exclusive use of steam-propelled vessels. Pepys' advice in scientific and technical matters was widely sought and freely given; he retained his mental powers to the end of his long life, fulfilling his professional commitments until a few days before his death.     

A History of the Surrey Institution

The Surrey Institution, Blackfriars, founded in 1808, was, after the Royal Institution and London Institution, the third establishment in London aimed at fostering and disseminating scientific, technical, and literary knowledge and understanding among a wider public. The Institution offered its proprietors and subscribers the use of an extensive reference library and reading rooms and, most importantly, the opportunity to attend courses of lectures on scientific, technological, and other subjects. Though popular in approach, the lectures conformed to high educational standards and were delivered by recognized authorities in their fields. In the Surrey Institution's celebrated auditorium, the 'Rotunda', there appeared over the years such notable scientists as Accum, Thomson, and Gurney on chemistry, Millington, Mason Good, and Woodward on natural philosophy, Bakewell on geology, and Shaw on natural history; literature was brilliantlyrepresented by Coleridge and Hazlitt. During its relatively brief life-span (1808-23)-cut short by financial stringencies-the Surrey Institution provided access to scientific knowledge and thinking to a wide and appreciative audience. As a meeting place fo scientists and men of business with mercantile and manufacturing interests, it performed an important function in cross-fertilizing and reinforcing ideas on innovation and enterprise against the background of the ongoing Industrial Revolution. The present article attempts to supply a historical account, so far lacking, of the foundation, activities and achievements of this significant Institution of the metropolis.     

鸡传染性法氏囊病病毒VP5基因的克隆及其序列分析

从病变鸡法氏囊组织中分离纯化IBDV,提取其基因组RNA.以IBDVRNA为模板,进行反转录反应合成cDNA第1链.采用PCR技术扩增VP5基因.将PCR产物经酶切后与pcDNA3.1(+)载体连接,经转化、筛选得到重组质粒pIBDV-VP5.对VP5基因进行了测序并对其序列进行了分析.     

Role of cholesterol and lipid organization in disease

Membrane lipids are essential for biological functions ranging from membrane trafficking to signal transduction. The composition of lipid membranes influences their organization and properties, so it is not surprising that disorders in lipid metabolism and transport have a role in human disease. Significant recent progress has enhanced our understanding of the molecular and cellular basis of lipid-associated disorders such as Tangier disease, Niemann-Pick disease type C and atherosclerosis. These insights have also led to improved understanding of normal physiology.     

Pseudomonas biofilm formation and antibiotic resistance are linked to phenotypic variation

Colonization of the lungs of cystic fibrosis (CF) patients by the opportunistic bacterial pathogen Pseudomonas aeruginosa is the principal cause of mortality in CF populations. Pseudomonas aeruginosa infections generally persist despite the use of long-term antibiotic therapy. This has been explained by postulating that P. aeruginosa forms an antibiotic-resistant biofilm consisting of bacterial communities embedded in an exopolysaccharide matrix. Alternatively, it has been proposed that resistant P. aeruginosa variants may be selected in the CF respiratory tract by antimicrobial therapy itself. Here we report that both explanations are correct, and are interrelated. We found that antibiotic-resistant phenotypic variants of P. aeruginosa with enhanced ability to form biofilms arise at high frequency both in vitro and in the lungs of CF patients. We also identified a regulatory protein (PvrR) that controls the conversion between antibiotic-resistant and antibiotic-susceptible forms. Compounds that affect PvrR function could have an important role in the treatment of CF infections.