This study quantifies seismic amplifications in near-shore arising from seaquakes. Within the Boundary Element Method, boundary elements are used to irradiate waves and force densities obtained for each element. Huyg...This study quantifies seismic amplifications in near-shore arising from seaquakes. Within the Boundary Element Method, boundary elements are used to irradiate waves and force densities obtained for each element. Huygens′ Principle is implemented since the diffracted waves are constructed at the boundary from which they are radiated, which is equivalent to Somigliana′s theorem. Application of boundary conditions leads to a system of integral equations of the Fredholm type of second kind and zero order. Several numerical configurations are analyzed： The first is used to verify the present formulation with ideal sea floor configurations to estimate seismic amplifications. With the formulation verified, simple slope configurations are studied to estimate spectra of seismic motions. It is found that P-waves can produce seismic amplifications from 1.2 to 3.9 times the amplitude of the incident wave. SV-waves can generate seismic amplifications up to 4.5 times the incident wave. Another relevant finding is that the highest amplifications are at the shore compared to the ones at the sea floor.展开更多
Purpose:Spinal injuries resulting in neurological damage cause significant morbidity.Swift neurosurgical intervention can mitigate negative outcomes.However,variable mechanisms of injury may be associated with inappro...Purpose:Spinal injuries resulting in neurological damage cause significant morbidity.Swift neurosurgical intervention can mitigate negative outcomes.However,variable mechanisms of injury may be associated with inappropriate transport(IAT),which may delay necessary surgical interventions.Patients with near shore spinal injuries(NSSI)presented with unique mechanisms,so we investigated factors associated with IAT in patients with NSSI.Methods:We performed a multicenter retrospective study of all adult patients transported from a beach resort to 3 hospitals for suspected NSSI between 2006-2017.We excluded patients transferred to other facilities,and those not injured in the water.Primary outcome was IAT,defined as patients with NSSI requiring transfer to another trauma center.To avoid heterogeneity in our analysis,we further excluded patients without NSSI who were inappropriately transported to a level I trauma center.We used multivariable logistic regression to assess association of independent variables(such as demographic,environmental,and clinical factors)with outcome.Results:We analyzed 278 patients with suspected NSSI,and found 14(5.0%)had IAT.Compared to appropriately transported patients,diving was associated with higher percentages of IAT(28.6%vs.3.9%,p=0.014)and more were transported by air(50.0%vs.20.6%,p=0.01).In multivariable regression,patients'oxygenation saturation(odds ratio[OR]=0.8,95%confidence intervals[Cl]:077-0.98)and diving(OR=7.5,95%Cl:1.2-46)were significantly associated with IAT.Conclusion:Rate of IAT for patients with NSSI was low.However,first responders and emergency medicine providers should be aware that diving is associated with a higher likelihood of IAT.展开更多
文摘This study quantifies seismic amplifications in near-shore arising from seaquakes. Within the Boundary Element Method, boundary elements are used to irradiate waves and force densities obtained for each element. Huygens′ Principle is implemented since the diffracted waves are constructed at the boundary from which they are radiated, which is equivalent to Somigliana′s theorem. Application of boundary conditions leads to a system of integral equations of the Fredholm type of second kind and zero order. Several numerical configurations are analyzed： The first is used to verify the present formulation with ideal sea floor configurations to estimate seismic amplifications. With the formulation verified, simple slope configurations are studied to estimate spectra of seismic motions. It is found that P-waves can produce seismic amplifications from 1.2 to 3.9 times the amplitude of the incident wave. SV-waves can generate seismic amplifications up to 4.5 times the incident wave. Another relevant finding is that the highest amplifications are at the shore compared to the ones at the sea floor.
文摘Purpose:Spinal injuries resulting in neurological damage cause significant morbidity.Swift neurosurgical intervention can mitigate negative outcomes.However,variable mechanisms of injury may be associated with inappropriate transport(IAT),which may delay necessary surgical interventions.Patients with near shore spinal injuries(NSSI)presented with unique mechanisms,so we investigated factors associated with IAT in patients with NSSI.Methods:We performed a multicenter retrospective study of all adult patients transported from a beach resort to 3 hospitals for suspected NSSI between 2006-2017.We excluded patients transferred to other facilities,and those not injured in the water.Primary outcome was IAT,defined as patients with NSSI requiring transfer to another trauma center.To avoid heterogeneity in our analysis,we further excluded patients without NSSI who were inappropriately transported to a level I trauma center.We used multivariable logistic regression to assess association of independent variables(such as demographic,environmental,and clinical factors)with outcome.Results:We analyzed 278 patients with suspected NSSI,and found 14(5.0%)had IAT.Compared to appropriately transported patients,diving was associated with higher percentages of IAT(28.6%vs.3.9%,p=0.014)and more were transported by air(50.0%vs.20.6%,p=0.01).In multivariable regression,patients'oxygenation saturation(odds ratio[OR]=0.8,95%confidence intervals[Cl]:077-0.98)and diving(OR=7.5,95%Cl:1.2-46)were significantly associated with IAT.Conclusion:Rate of IAT for patients with NSSI was low.However,first responders and emergency medicine providers should be aware that diving is associated with a higher likelihood of IAT.
