The sedimentary rocks of the Cabullona Group are well exposed in the Cabullona Basin of northeastern Sonora,Mexico,which represent syntectonic sedimentation associated with Laramide-style deformation during the Campan...The sedimentary rocks of the Cabullona Group are well exposed in the Cabullona Basin of northeastern Sonora,Mexico,which represent syntectonic sedimentation associated with Laramide-style deformation during the Campanian-early Maastrichtian.The sandstones of the Lomas Coloradas Formation deposited at the upper part of the Cabullona Group.Petrography and geochemical(major,trace,and rare earth elements)studies were carried out on the sandstones to interpret the palaeoweathering,provenance,and tectonic setting of the Lomas Coloradas Formation sandstones.Most of the sandstone modal analysis data plotted in the QFL and Qm FLt ternary diagrams fall into the fields of dissected arcs and recycled orogens,respectively.Geochemically the sandstones are classified as litharenites while few samples plot into the arkosic field.The chondrite-normalized REE diagrams for sandstones have LREE-enriched,relatively flat HREE patterns with negative Eu anomalies.CIA values and the A-CN-K diagram indicate a low intensity of chemical weathering in the source area.The tectonic setting diagram suggests both arc and rift settings for the studied sandstones.The bivariate and ternary diagrams and elemental ratios suggest a felsic source for the Lomas Coloradas Formation.The average REE patterns of the studied sandstones are comparable with REE patterns of the granite from the Caborca block,the rhyolite and granite of the Tarahumara Formation,and the Mesozoic felsic volcanic rocks.The modeled mixture of 40%Proterozoic granite,30%Triassic arc,10%Jurassic arc,and 20%Laramide arc represents the probable source rocks for the Lomas Coloradas Formation.展开更多
A comparative study of selected bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes is described in this paper. Typical ground motion effects considered include large ground fault d...A comparative study of selected bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes is described in this paper. Typical ground motion effects considered include large ground fault displacement, liquefaction, landslide, and strong ground shaking. Issues related to falling spans, inadequate detailing for structural ductility and complex bridge configurations are discussed within the context of the recent seismic design codes of China and the US. A significant lesson learned from the Great Wenchuan earthquake, far beyond the opportunities to improve the seismic design provisions for bridges, is articulated.展开更多
AIM: To investigate the frequency of occult hepatitis B, the clinical course of hepatitis B virus (HBV) reactivation and reverse seroconversion and associated risk factors in autologous hematopoietic stem cell transpl...AIM: To investigate the frequency of occult hepatitis B, the clinical course of hepatitis B virus (HBV) reactivation and reverse seroconversion and associated risk factors in autologous hematopoietic stem cell transplantation (HSCT) recipients. METHODS: This study was conducted in 90 patients undergoing autologous HSCT. Occult HBV infection was investigated by HBV-DNA analysis prior to transplantation, while HBV serology and liver function tests were screened prior to and serially after transplantation. HBV-related events including reverse seroconversion and reactivation were recorded in all patients. RESULTS: None of the patients had occult HBV prior to transplantation. Six (6.7%) patients were positivefor HBV surface antigen (HBsAg) prior to transplantation and received lamivudine prophylaxis; they did not develop HBV reactivation after transplantation. Clinical HBV infection emerged in three patients after transplantation who had negative HBV-DNA prior to HSCT. Two of these three patients had HBV reactivation while one patient developed acute hepatitis B. Three patients had anti-HBc as the sole hepatitis B-related antibody prior to transplantation, two of whom developed hepatitis B reactivation while none of the patients with antibody to HBV surface antigen (anti-HBs) did so. The 14 anti-HBs-and/or anti-HBc-positive patients among the 90 HSCT recipients experienced either persistent (8 patients) or transient (6 patients) disappearance of anti-HBs and/or anti-HBc. HBsAg seroconversion and clinical hepatitis did not develop in these patients. Female gender and multiple myeloma emerged as risk factors for loss of antibody in regression analysis (P < 0.05). CONCLUSION: Anti-HBc as the sole HBV marker seems to be a risk factor for reactivation after autologous HSCT. Lamivudine prophylaxis in HbsAg-positive patients continues to be effective.展开更多
Based on three-dimensional joint finite element, this paper discusses the theory and methodology about inversionof geodetic data. The FEM and inversion formula is given in detail; also a related code is developed. By ...Based on three-dimensional joint finite element, this paper discusses the theory and methodology about inversionof geodetic data. The FEM and inversion formula is given in detail; also a related code is developed. By use of theGreen's function about 3-D FEM, we invert geodetic measurementS of coseismic deformation of the 1989 Ms=7. 1Loma Prieta earthquake to datermine itS source mechanism. The result indicates that the slip on the fault plane isvery heterogeneous. The maximum slip and shear stress are located about 10 kin to northwest of the eathquakesource, the stress drop is about more than 1 MPa.展开更多
笔者于2003年1—4月在美国加州罗玛琳达大学医学中心儿童医院(Loma Linda University Medical Center Children Hospital)新生儿重症监护病房(NICU)学习，该NICU有80张床位，极低出生体重早产儿(VLBWI)是主要病种之一，现将其极低出生...笔者于2003年1—4月在美国加州罗玛琳达大学医学中心儿童医院(Loma Linda University Medical Center Children Hospital)新生儿重症监护病房(NICU)学习，该NICU有80张床位，极低出生体重早产儿(VLBWI)是主要病种之一，现将其极低出生体重早产儿部分管理常规简介如下。展开更多
Disaster preparedness is very important for business continuity, but the determinants of disaster preparedness in business organizations have not been explored much in existing research. Therefore, in this article we ...Disaster preparedness is very important for business continuity, but the determinants of disaster preparedness in business organizations have not been explored much in existing research. Therefore, in this article we undertake to analyze the influences of organizational and decision makers’ characteristics on business disaster preparedness. In 1997, eight years after the Loma Prieta earthquake, the Disaster Research Center at University of Delaware conducted a large-scale mail questionnaire survey in Santa Cruz County, California, which was hard-hit by the 1989 earthquake. A total of 933 completed surveys from business organizations were obtained. Our analysis is based on this historical dataset. The results revealed that larger companies are more likely to engage in disaster preparedness activities, which is consistent with previous studies. Companies in finance, insurance, and real estate sectors tend to prepare more for disasters compared with wholesale and retail trade firms. Disaster experience has a significant and positive impact on business disaster preparedness, and the degree of lifeline loss can be a reasonable indicator of the disaster experiences of business organizations. One interesting finding is that the better a company’s financial condition is, the less it will engage in preparing for disasters. Finally, the risk perception of business owners or decision makers has a statistically significant and consistent positive effect on business disaster preparedness activities.展开更多
基金financially supported by the Programa de Apoyo a Proyectos de Investigaci on e Innovaci on Tecnol ogica (PAPIIT)Projects (Nos.IN112214 and IN109422)by Direcci on General de Asuntos del Personal Acad emico,Universidad Nacional Aut onoma de MexicoDirecci on General de Asuntos del Personal Academico (DGAPA),Universidad Nacional Autonoma de Mexico (UNAM)for financial support through PAPIIT Projects (Nos.IN112214 and IN109422)。
文摘The sedimentary rocks of the Cabullona Group are well exposed in the Cabullona Basin of northeastern Sonora,Mexico,which represent syntectonic sedimentation associated with Laramide-style deformation during the Campanian-early Maastrichtian.The sandstones of the Lomas Coloradas Formation deposited at the upper part of the Cabullona Group.Petrography and geochemical(major,trace,and rare earth elements)studies were carried out on the sandstones to interpret the palaeoweathering,provenance,and tectonic setting of the Lomas Coloradas Formation sandstones.Most of the sandstone modal analysis data plotted in the QFL and Qm FLt ternary diagrams fall into the fields of dissected arcs and recycled orogens,respectively.Geochemically the sandstones are classified as litharenites while few samples plot into the arkosic field.The chondrite-normalized REE diagrams for sandstones have LREE-enriched,relatively flat HREE patterns with negative Eu anomalies.CIA values and the A-CN-K diagram indicate a low intensity of chemical weathering in the source area.The tectonic setting diagram suggests both arc and rift settings for the studied sandstones.The bivariate and ternary diagrams and elemental ratios suggest a felsic source for the Lomas Coloradas Formation.The average REE patterns of the studied sandstones are comparable with REE patterns of the granite from the Caborca block,the rhyolite and granite of the Tarahumara Formation,and the Mesozoic felsic volcanic rocks.The modeled mixture of 40%Proterozoic granite,30%Triassic arc,10%Jurassic arc,and 20%Laramide arc represents the probable source rocks for the Lomas Coloradas Formation.
文摘A comparative study of selected bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes is described in this paper. Typical ground motion effects considered include large ground fault displacement, liquefaction, landslide, and strong ground shaking. Issues related to falling spans, inadequate detailing for structural ductility and complex bridge configurations are discussed within the context of the recent seismic design codes of China and the US. A significant lesson learned from the Great Wenchuan earthquake, far beyond the opportunities to improve the seismic design provisions for bridges, is articulated.
基金Supported by The Society of Postgraduate Education of Internal Medicine
文摘AIM: To investigate the frequency of occult hepatitis B, the clinical course of hepatitis B virus (HBV) reactivation and reverse seroconversion and associated risk factors in autologous hematopoietic stem cell transplantation (HSCT) recipients. METHODS: This study was conducted in 90 patients undergoing autologous HSCT. Occult HBV infection was investigated by HBV-DNA analysis prior to transplantation, while HBV serology and liver function tests were screened prior to and serially after transplantation. HBV-related events including reverse seroconversion and reactivation were recorded in all patients. RESULTS: None of the patients had occult HBV prior to transplantation. Six (6.7%) patients were positivefor HBV surface antigen (HBsAg) prior to transplantation and received lamivudine prophylaxis; they did not develop HBV reactivation after transplantation. Clinical HBV infection emerged in three patients after transplantation who had negative HBV-DNA prior to HSCT. Two of these three patients had HBV reactivation while one patient developed acute hepatitis B. Three patients had anti-HBc as the sole hepatitis B-related antibody prior to transplantation, two of whom developed hepatitis B reactivation while none of the patients with antibody to HBV surface antigen (anti-HBs) did so. The 14 anti-HBs-and/or anti-HBc-positive patients among the 90 HSCT recipients experienced either persistent (8 patients) or transient (6 patients) disappearance of anti-HBs and/or anti-HBc. HBsAg seroconversion and clinical hepatitis did not develop in these patients. Female gender and multiple myeloma emerged as risk factors for loss of antibody in regression analysis (P < 0.05). CONCLUSION: Anti-HBc as the sole HBV marker seems to be a risk factor for reactivation after autologous HSCT. Lamivudine prophylaxis in HbsAg-positive patients continues to be effective.
文摘Based on three-dimensional joint finite element, this paper discusses the theory and methodology about inversionof geodetic data. The FEM and inversion formula is given in detail; also a related code is developed. By use of theGreen's function about 3-D FEM, we invert geodetic measurementS of coseismic deformation of the 1989 Ms=7. 1Loma Prieta earthquake to datermine itS source mechanism. The result indicates that the slip on the fault plane isvery heterogeneous. The maximum slip and shear stress are located about 10 kin to northwest of the eathquakesource, the stress drop is about more than 1 MPa.
文摘笔者于2003年1—4月在美国加州罗玛琳达大学医学中心儿童医院(Loma Linda University Medical Center Children Hospital)新生儿重症监护病房(NICU)学习，该NICU有80张床位，极低出生体重早产儿(VLBWI)是主要病种之一，现将其极低出生体重早产儿部分管理常规简介如下。
文摘Disaster preparedness is very important for business continuity, but the determinants of disaster preparedness in business organizations have not been explored much in existing research. Therefore, in this article we undertake to analyze the influences of organizational and decision makers’ characteristics on business disaster preparedness. In 1997, eight years after the Loma Prieta earthquake, the Disaster Research Center at University of Delaware conducted a large-scale mail questionnaire survey in Santa Cruz County, California, which was hard-hit by the 1989 earthquake. A total of 933 completed surveys from business organizations were obtained. Our analysis is based on this historical dataset. The results revealed that larger companies are more likely to engage in disaster preparedness activities, which is consistent with previous studies. Companies in finance, insurance, and real estate sectors tend to prepare more for disasters compared with wholesale and retail trade firms. Disaster experience has a significant and positive impact on business disaster preparedness, and the degree of lifeline loss can be a reasonable indicator of the disaster experiences of business organizations. One interesting finding is that the better a company’s financial condition is, the less it will engage in preparing for disasters. Finally, the risk perception of business owners or decision makers has a statistically significant and consistent positive effect on business disaster preparedness activities.
