Liquefaction Assessment and Lateral Spreading in Nantou, Taiwan

On September 21, 1999, Taiwan was struck by an earthquake, called Chi-Chi earthquake, one of the largest in 100 years. The epicenter was located 12.5 km west of the Sun Moon Lake (Northern Latitude 23.85°) Eastern Longitude 120.78°), with focal depth of 8 km, and magnitude of Mw=7.6 (USGS). This earthquake caused heavy casualties and severe property damages around central Taiwan. It was found that this earthquake resulted in sand boiling, differential settlement on the ground and lateral spreading around part of the Maolou River bank in Nantou City. Field investigation, geological exploration and in situ tests, which include 14 borings with standard penetration tests and 8 cone penetration test soundings, were conducted to demonstrate the soil profiles and to perform soil liquefaction potential assessment. The ground failure due to spreading liquefaction near Maolou River bank was also described. The result revealed that soils about 5-8 meters below the ground surface contains fine to medium silty sand or sandy silt which is the same strata as the highest liquefaction potential based on SPT-N and CPT-qc liquefaction simplified procedures. It is also shown that the critical depth also has the physical properties similar to the boiled sand taken from the sand volcanoes

COSMOS2020: Exploring the dawn of quenching for massive galaxies at 3 < z < 5 with a new colour selection method

We select and characterise a sample of massive (log(M$_{*}/$M$_{\odot})>10.6$) quiescent galaxies (QGs) at $3<z<5$ in the latest COSMOS2020 catalogue. QGs are selected using a new rest-frame colour selection method, based on their probability of belonging to the quiescent group defined by a Gaussian Mixture Model (GMM) trained on rest-frame colours ($NUV-U, U-V, V-J$) of similarly massive galaxies at $2<z<3$. We calculate the quiescent probability threshold above which a galaxy is classified as quiescent using simulated galaxies from the SHARK semi-analytical model. We find that at $z\geq3$ in SHARK, the GMM/$NUVU-VJ$ method out-performs classical rest-frame $UVJ$ selection and is a viable alternative. We select galaxies as quiescent based on their probability in COSMOS2020 at $3<z<5$, and compare the selected sample to both $UVJ$ and $NUVrJ$ selected samples. We find that although the new selection matches $UVJ$ and $NUVrJ$ in number, the overlap between colour selections is only $\sim50-80\%$, implying that rest-frame colour commonly used at lower redshifts selections cannot be equivalently used at $z>3$. We compute median rest-frame SEDs for our sample and find the median quiescent galaxy at $3<z<5$ has a strong Balmer/4000 Angstrom break, and residual $NUV$ flux indicating recent quenching. We find the number densities of the entire quiescent population (including post-starbursts) more than doubles from $3.5\pm2.2\times10^{-6}$ Mpc$^{-3}$ at $4<z<5$ to $1.4\pm0.4\times10^{-5}$ Mpc$^{-3}$ at $3<z<4$, confirming that the onset of massive galaxy quenching occurs as early as $3<z<5$.Comment: 19 pages, 10 figures + appendix. Accepted for publication in AJ. Both the GMM model and code to calculate quiescent probabilities from rest frame flux densities are made available online at https://github.com/kmlgould/GMM-quiescen

A narrative inquiry into the identity formation of Chinese doctoral students in relation to study abroad

The present study explores a topic which has been under-studied to date, namely the identity formation of Chinese PhD students in relation to study abroad. Underpinned by Giddens' (1991) "reflexive project of the self", which privileges agency and reflexivity, and using a narrative inquiry approach, it presents four students' 'stories' collected through semi-structured interviews and focus group discussions in the form of a trajectory of development fro past to future. In building a picture of theways in which students' self-identity is shaped by and shapes their experience of study abroad, the stories illustrate individual agency, motivation, self-determination and reflexivity. In doing so, they challenge the essentialised view of Chinese students as a homogeneous and sometimes problematic group and point to implications for action by the host institutions

Biomechanical analysis of the lumbar spine on facet joint force and intradiscal pressure - a finite element study

<p>Abstract</p> <p>Background</p> <p>Finite element analysis results will show significant differences if the model used is performed under various material properties, geometries, loading modes or other conditions. This study adopted an FE model, taking into account the possible asymmetry inherently existing in the spine with respect to the sagittal plane, with a more geometrically realistic outline to analyze and compare the biomechanical behaviour of the lumbar spine with regard to the facet force and intradiscal pressure, which are associated with low back pain symptoms and other spinal disorders. Dealing carefully with the contact surfaces of the facet joints at various levels of the lumbar spine can potentially help us further ascertain physiological behaviour concerning the frictional effects of facet joints under separate loadings or the responses to the compressive loads in the discs.</p> <p>Methods</p> <p>A lumbar spine model was constructed from processes including smoothing the bony outline of each scan image, stacking the boundary lines into a smooth surface model, and subsequent further processing in order to conform with the purpose of effective finite element analysis performance. For simplicity, most spinal components were modelled as isotropic and linear materials with the exception of spinal ligaments (bilinear). The contact behaviour of the facet joints and changes of the intradiscal pressure with different postures were analyzed.</p> <p>Results</p> <p>The results revealed that asymmetric responses of the facet joint forces exist in various postures and that such effect is amplified with larger loadings. In axial rotation, the facet joint forces were relatively larger in the contralateral facet joints than in the ipsilateral ones at the same level. Although the effect of the preloads on facet joint forces was not apparent, intradiscal pressure did increase with preload, and its magnitude increased more markedly in flexion than in extension and axial rotation.</p> <p>Conclusions</p> <p>Disc pressures showed a significant increase with preload and changed more noticeably in flexion than in extension or in axial rotation. Compared with the applied preloads, the postures played a more important role, especially in axial rotation; the facet joint forces were increased in the contralateral facet joints as compared to the ipsilateral ones at the same level of the lumbar spine.</p

Diagnostic accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis: An international case-cohort study

We conducted an international study of idiopathic pulmonary fibrosis (IPF) diagnosis among a large group of physicians and compared their diagnostic performance to a panel of IPF experts. A total of 1141 respiratory physicians and 34 IPF experts participated. Participants evaluated 60 cases of interstitial lung disease (ILD) without interdisciplinary consultation. Diagnostic agreement was measured using the weighted kappa coefficient (\u3baw). Prognostic discrimination between IPF and other ILDs was used to validate diagnostic accuracy for first-choice diagnoses of IPF and were compared using the Cindex. A total of 404 physicians completed the study. Agreement for IPF diagnosis was higher among expert physicians (\u3baw=0.65, IQR 0.53-0.72, p20 years of experience (C-index=0.72, IQR 0.0-0.73, p=0.229) and non-university hospital physicians with more than 20 years of experience, attending weekly MDT meetings (C-index=0.72, IQR 0.70-0.72, p=0.052), did not differ significantly (p=0.229 and p=0.052 respectively) from the expert panel (C-index=0.74 IQR 0.72-0.75). Experienced respiratory physicians at university-based institutions diagnose IPF with similar prognostic accuracy to IPF experts. Regular MDT meeting attendance improves the prognostic accuracy of experienced non-university practitioners to levels achieved by IPF experts

Estimates o the risks associated with dam failure

The probabilities and potential consequences of dam failure in California, primarily due to large earthquakes, was estimated, taking as examples eleven dams having a relatively large population downstream. Mortalities in the event of dam failure range from 11,000 to 260,000, while damage to property may be as high as $720 million. It was assumed that an intensity IX or X earthquake (on the Modified Mercalli Scale) would be sufficient to completely fail earthen dams. Predictions of dam failure were based on the recurrence times of such earthquakes. For the dams studied, the recurrence intervals for an intensity IX earthquake varied between 20 and 800 years; for an intensity X between 50 and 30,000 years. For the Lake Chabot and San Pablo dams (respectively 20, 30 years recurrent earthquake times for a intensity X) the associated consequences are: 34,000 (Lake Chabot) and 30,000 (San Pablo) people killed; damage$140 million and $77 million. Evaculation was found to ameliorate the consequences slightly in most cases because of the short time available. Calculations are based on demography, and assume 10 foot floodwaters will drown all in their path and destroy all one-unit homes in the flood area. Damage estimates reflect losses incurred by structural damage to buildings and do not include loss of income. Hence the economic impact is probably understated

Multidimensional Victimization and Internet Addiction among Taiwanese Children

This study examines (1) associations between four types of family and peer victimization and child internet addiction and (2) the mediating effects of psychological symptoms on these associations. Data were collected from a national proportionately-stratified random sample of 6,233 fourth-grade primary school students in Taiwan in 2014. Bivariate correlations and sets of multiple regression analyses were conducted to examine the direct effects of multi dimensional victimization on child internet addiction and the indirect effects through psychological symptoms. The results reveal that being male and experiencing victimization (psychological neglect, physical neglect, witnessing domestic violence, and bully victimization) are associated with an increased risk of developing psychological symptoms and internet addiction among children. Moreover, we found that psychological symptoms partially mediate the associations between multidimensional victimization and child internet addiction, with the exception of physical neglect. In conclusion, this study demonstrates (1) the direct and indirect effects of multidimensional victimization on the psychological symptoms and child internet addiction, and (2) the importance of early family- and school-based prevention and intervention in addressing related public health concerns of multidimensional victimization and child internet addiction