In subtropical volcanic environments, there are often few accessible outcrops. These are often highly weathered and of very poor quality. Soil development is rapid (1 cm/y) and small eruptions are unlikely to be prese...In subtropical volcanic environments, there are often few accessible outcrops. These are often highly weathered and of very poor quality. Soil development is rapid (1 cm/y) and small eruptions are unlikely to be preserved in the geological record. Reconstructing past eruptions and assessing hazards is a challenge. Here, we studied a poorly outcropping tuff ring (very poor, incomplete sections) with the best outcrop observed at a beach cliff (up to ca. 5 - 10 m high) at Batoke, to the south of Mt Cameroon volcano. Mt Cameroon has a few tuff rings, currently of unknown ages, near the SW coast of Cameroon. In the Batoke case, the sequence is dominated by gently dipping tuff beds varying in the proportion of lithics, juvenile clasts, and accretionary lapilli (acc-laps). Several beds are close-packed with acc-laps of up to 10 - 15 mm diameter. Part of the section is gullied by mud flow deposits. The rocks are highly weathered but differential weathering enhances relationships. Quantitative data can be extracted from a detailed study of outcrops’ external surfaces. The preserved section is close to where the deposits were initially thickest and where acc-laps were most abundant and largest. There is an empirical correlation between maximum acc-lap size in the thickest outcrop and eruption column height. This and the deposit features suggest that the Batoke eruption was pulsating but dominated by fallout, with a water and ice-rich eruption column reaching 10 - 15 km high. Recycling of water drops and ice-coated fine ash accumulated during eruption. At switch off, wholesale gravitational collapse of this material produced the mud flows, which gullied the previously-laid down deposits. Such ash fall and mud flows can represent a substantial hazard, e.g. they can gully down through towns and roads and cut evacuation routes. This study illustrates how, at subtropical tuff rings, it is possible to extract key data needed for hazard assessment from only 1 - 2 poor outcrops.展开更多
Primary biliary cirrhosis(PBC) is an autoimmune disease of the liver characterized by progressive bile duct destruction eventually leading to cirrhosis and liver failure.The serological hallmark of the disease is the ...Primary biliary cirrhosis(PBC) is an autoimmune disease of the liver characterized by progressive bile duct destruction eventually leading to cirrhosis and liver failure.The serological hallmark of the disease is the presence of circulating antimitochondrial antibodies(AMA).These reflect the presence of autoreactive T and B cells to the culprit antigens,the E2 subunits of mitochondrial 2-oxo-acid dehydrogenase enzymes,chiefly pyruvate dehydrogenase(PDC-E2).The disease results from a combination of genetic and environmental risk factors.Genetic predisposition is indicated by the higher familial incidence of the disease particularly among siblings and the high concordance rate among monozygotic twins.Environmental triggering events appear crucial to disrupt a pre-existing unstable immune tolerance of genetic origin allowing,after a long latency,the emergence of clinical disease.Initiating mimetopes of the vulnerable epitope of the PDC-E2 autoantigen can be derived from microbes that utilize the PDC enzyme or,alternatively,environmental xenobiotics/chemical compounds that modify the structure of native proteins to make them immunogenic.A further alternative as a source of antigen is PDC-E2 derived from apoptotic cells.In the effector phase the biliary ductular cell,by reason of itsproclivity to express the antigen PDC-E2 in the course of apoptosis,undergoes a multilineage immune attack comprised of CD4+ and CD8+ T cells and antibody.In this article,we critically review the available evidence on etiopathogenesis of PBC and present interpretations of complex data,new developments and theories,and nominate directions for future research.展开更多
WEEE(Waste Electrical and Electronic Equipment),also called e-waste,has become the world’s fastest-growing waste stream but only has a 17.4%recycling rate according to the Global E-waste Monitor 2020.The collection r...WEEE(Waste Electrical and Electronic Equipment),also called e-waste,has become the world’s fastest-growing waste stream but only has a 17.4%recycling rate according to the Global E-waste Monitor 2020.The collection rate for sWEEE(Small WEEE),e.g.,used mobile phones,is even lower than 10%due to stockpiling at home and improper disposal via the general waste or private informal channels.The purpose of this paper was to(a)review how the TPB(Theory of Planned Behavior)was applied in the literature related to consumer behavioral intention for WEEE recycling and determine the most significant TPB predictors by comparing their standardized influence coefficients across various studies,and(b)identify additional behavior determinants specific to sWEEE recycling and thus develop a new TPB-sWEEE theoretical framework by integrating the TPB model with these new determinants in order to improve the predictability of consumers’sWEEE recycling behavioral intention.This paper reviewed over 30 peer-reviewed studies from Scopus and high impact factor journals and led to the following three key findings:(a)More variables of recycling behavioral intention determinants such as the size of WEEE need to be considered;(b)Eight sWEEE-specific behavioral determinants have been identified and included in the newly developed TPB-sWEEE model,including consumers’Sentimental Attachment,Data Security Concern,Economic Incentives,and How-to Knowledge;(c)For some sWEEE-specific determinants,their extent of influence differs across various regions and countries.This paper contributes to the sWEEE-specific consumer recycling behavior theoretical framework to fill the existing gap in the literature and provides recommendations through the new model for research-based behavioral intervention strategies and policy designs globally.展开更多
文摘In subtropical volcanic environments, there are often few accessible outcrops. These are often highly weathered and of very poor quality. Soil development is rapid (1 cm/y) and small eruptions are unlikely to be preserved in the geological record. Reconstructing past eruptions and assessing hazards is a challenge. Here, we studied a poorly outcropping tuff ring (very poor, incomplete sections) with the best outcrop observed at a beach cliff (up to ca. 5 - 10 m high) at Batoke, to the south of Mt Cameroon volcano. Mt Cameroon has a few tuff rings, currently of unknown ages, near the SW coast of Cameroon. In the Batoke case, the sequence is dominated by gently dipping tuff beds varying in the proportion of lithics, juvenile clasts, and accretionary lapilli (acc-laps). Several beds are close-packed with acc-laps of up to 10 - 15 mm diameter. Part of the section is gullied by mud flow deposits. The rocks are highly weathered but differential weathering enhances relationships. Quantitative data can be extracted from a detailed study of outcrops’ external surfaces. The preserved section is close to where the deposits were initially thickest and where acc-laps were most abundant and largest. There is an empirical correlation between maximum acc-lap size in the thickest outcrop and eruption column height. This and the deposit features suggest that the Batoke eruption was pulsating but dominated by fallout, with a water and ice-rich eruption column reaching 10 - 15 km high. Recycling of water drops and ice-coated fine ash accumulated during eruption. At switch off, wholesale gravitational collapse of this material produced the mud flows, which gullied the previously-laid down deposits. Such ash fall and mud flows can represent a substantial hazard, e.g. they can gully down through towns and roads and cut evacuation routes. This study illustrates how, at subtropical tuff rings, it is possible to extract key data needed for hazard assessment from only 1 - 2 poor outcrops.
文摘Primary biliary cirrhosis(PBC) is an autoimmune disease of the liver characterized by progressive bile duct destruction eventually leading to cirrhosis and liver failure.The serological hallmark of the disease is the presence of circulating antimitochondrial antibodies(AMA).These reflect the presence of autoreactive T and B cells to the culprit antigens,the E2 subunits of mitochondrial 2-oxo-acid dehydrogenase enzymes,chiefly pyruvate dehydrogenase(PDC-E2).The disease results from a combination of genetic and environmental risk factors.Genetic predisposition is indicated by the higher familial incidence of the disease particularly among siblings and the high concordance rate among monozygotic twins.Environmental triggering events appear crucial to disrupt a pre-existing unstable immune tolerance of genetic origin allowing,after a long latency,the emergence of clinical disease.Initiating mimetopes of the vulnerable epitope of the PDC-E2 autoantigen can be derived from microbes that utilize the PDC enzyme or,alternatively,environmental xenobiotics/chemical compounds that modify the structure of native proteins to make them immunogenic.A further alternative as a source of antigen is PDC-E2 derived from apoptotic cells.In the effector phase the biliary ductular cell,by reason of itsproclivity to express the antigen PDC-E2 in the course of apoptosis,undergoes a multilineage immune attack comprised of CD4+ and CD8+ T cells and antibody.In this article,we critically review the available evidence on etiopathogenesis of PBC and present interpretations of complex data,new developments and theories,and nominate directions for future research.
文摘WEEE(Waste Electrical and Electronic Equipment),also called e-waste,has become the world’s fastest-growing waste stream but only has a 17.4%recycling rate according to the Global E-waste Monitor 2020.The collection rate for sWEEE(Small WEEE),e.g.,used mobile phones,is even lower than 10%due to stockpiling at home and improper disposal via the general waste or private informal channels.The purpose of this paper was to(a)review how the TPB(Theory of Planned Behavior)was applied in the literature related to consumer behavioral intention for WEEE recycling and determine the most significant TPB predictors by comparing their standardized influence coefficients across various studies,and(b)identify additional behavior determinants specific to sWEEE recycling and thus develop a new TPB-sWEEE theoretical framework by integrating the TPB model with these new determinants in order to improve the predictability of consumers’sWEEE recycling behavioral intention.This paper reviewed over 30 peer-reviewed studies from Scopus and high impact factor journals and led to the following three key findings:(a)More variables of recycling behavioral intention determinants such as the size of WEEE need to be considered;(b)Eight sWEEE-specific behavioral determinants have been identified and included in the newly developed TPB-sWEEE model,including consumers’Sentimental Attachment,Data Security Concern,Economic Incentives,and How-to Knowledge;(c)For some sWEEE-specific determinants,their extent of influence differs across various regions and countries.This paper contributes to the sWEEE-specific consumer recycling behavior theoretical framework to fill the existing gap in the literature and provides recommendations through the new model for research-based behavioral intervention strategies and policy designs globally.
