Elastoplastic Large Deflection Analysis of Cold-formed Members Using Spline Finite Strip Method

The elastoplastic large deflection behaviour of cold-formed members is analysed by a nonlinear spline finite strip method. The method is developed using the principle of virtual work, based on the total Lagrangian description. It is used to deal with problems of geometric and material nonlinearity. The displacement function of a strip is expressed as the product of transverse interpolation polynomials and longitudinal B3-splines. The effect of arbitrary initial imperfections is taken into consideration. The influence of cold-bending residual stress on the local and overall behaviour of cold-formed lipped angle columns is investigated especially. The numeric examples show that the method possesses such advantages as fewer degrees of freedom, fine continuity, good boundary adaptation, quick computation speed and high accuracy etc

Cocoon-spinning behavior and 20-hydroxyecdysone regulation of fibroin genes in Plutella xylostella

The diamondback moth Plutella xylostella is a serious pest of crucifers. It has high reproductive potential and is resistant to many insecticides. Typically, the last-instar larvae of P. xylostella, before pupation, move to the lower or outer plant leaves to make a loose silk cocoon and pupate inside for adult formation. To better understand this pivotal stage we studied the cocoon-spinning behavior of P. xylostella and measured three successive phases by video-recording, namely the selection of a pupation site, spinning a loose cocoon and padding the scaffold cocoon. Subsequently, we cloned three fibroin genes related to cocoon production, i.e., fibroin light chain (Fib-L), fibroin heavy chain (Fib-H), and glycoprotein P25. A spatio-temporal study of these three fibroin genes confirmed a high expression in the silk glands during the final larval instar silk-producing stage. In parallel, we did an exogenous treatment of the insect molting hormone 20-hydroxyecdysone (20E), and this suppressed fibroin gene expression, reduced the normal time needed for cocoon spinning, and we also observed a looser cocoon structure under the scanning electron microscope. Hence, we demonstrated that the expression levels of key genes related to the synthesis of 20E [the three Halloween genes Spook (Spo), Shadow (Sad), and Shade (Shd)] decreased significantly during spinning, the expression of the 20E receptor (EcR and USP) was significantly lower during spinning than before spinning, and that the expression levels of CYP18-A1 related to 20E degradation were significantly up-regulated during spinning. The significance of the cocoon and the effects of 20E on the cocoon-spinning behavior of P. xylostella are discussed

The impact of revised CLSI cefazolin breakpoints on the clinical outcomes of Escherichia coli bacteremia

AbstractBackground/PurposeThe susceptibility breakpoints of cephalosporins for Enterobacteriaceae were revised by the Clinical and Laboratory Standards Institute (CLSI) in 2010 and 2011. The clinical outcome and susceptibility data were analyzed to evaluate the impact of revised CLSI cefazolin breakpoints on the treatment of Escherichia coli bacteremia.MethodsForty-three bacteremic Escherichia coli isolates from Taichung Veterans General Hospital, Taichung, Taiwan, during the period from January 2013 to December 2013, were selected to analyze the minimum inhibitory concentration (MIC) distributions of cefazolin and the correlated clinical responses to cefazolin therapy.ResultsThe modal cefazolin MIC among the 43 isolates was 1 μg/mL and accounted for 18 (42%) isolates. The cumulative percentage for MICs ≤ 2 μg/mL was 79%. The conventional dosing regimens achieved clinical cure in 33 (97%) of 34 patients with bacteremia due to E. coli with a cefazolin MIC ≤ 2 μg/mL, in all of the six patients with a cefazolin MIC of 4 μg/mL, and all of the three patients with a cefazolin MIC of 8 μg/mL.ConclusionThe microbiological data support the revised CLSI breakpoints of cefazolin. The conventional cefazolin dosing regimens can still achieve satisfactory clinical cure rates for bacteremia of E. coli with a cefazolin MIC ≤ 2 μg/mL in patients without severe septic shock. Before the approval of the efficacy of cefazolin for the treatment of E. coli isolates with a cefazolin MIC of 4 μg/mL, it is prudent to use cefazolin only when a high drug level can be achieved in the infection site, such as the urinary tract

Characterization of the Antheraea pernyi abnormal wing disc gene that may contribute to its temperature tolerance

It has been known that the abnormal wing disc (awd) gene encodes a nucleoside diphosphate kinase and is closely related to wing development in Drosophila melanogaster and Bombyx mori. In the present study, the awd gene was isolated and characterized from Antheraea pernyi, a well-known wild silkmoth. The isolated cDNA sequence is 666 bp in length with an open reading frame of 462 bp encoding a polypeptide of 153 amino acids, which contains a putative nucleoside diphosphate kinases active site motif and conserved multimer interface. The deduced A. pernyi awd protein sequence reveals 75, 82 and 96% identity with its homologue of Homo sapiens, D. melanogaster, and B. mori, respectively. Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that the awd gene was transcribed during all four developmental stages (egg, larva, pupa, and moth), and present in all tissues tested (blood, midgut, silk glands, Malpighian tublues, spermaries, ovaries, brain, muscle, fat body and body wall), with the highest abundance in Malpighian tubules. Interestingly, mRNA expression level in pupal fat body was significantly down-regulated after cold shock (4°C) compared with the control (26°C) and significantly up-regulated after heat shock (46°C). The results indicated that the A. pernyi awd gene is inducible, and that its expression effect is different after cold stress and heat stress. Consequently, we refer that the product of the awd gene may contribute to its temperature tolerance.Key words: Antheraea pernyi, abnormal wing disc gene, cloning, expression pattern, temperature stress

The association of molecular typing, vancomycin MIC, and clinical outcome for patients with methicillin-resistant Staphylococcus aureus infections

AbstractBackground/PurposeThere are reports of an increase in vancomycin minimum inhibitory concentration (MIC) against methicillin-resistant Staphylococcus aureus (MRSA) over time, a phenomenon referred to as “MIC creep”, but some studies have conflicting results. The aim of this study is to evaluate the association of molecular typing, vancomycin MIC, and clinical outcome for patients with MRSA infections.MethodsThirty-two MRSA isolates from Taichung Veterans General Hospital (TCVGH), Taichung, Taiwan during the period of 2003 to 2008 were analyzed for the association of sequence typing, vancomycin MIC, and the correlated clinical outcome for patients with MRSA infections. The vancomycin MICs of 28 additional isolates from 2014 were used for the detection of MIC creep.ResultsAmong the genotypes of 32 isolates, there were 17 (53.1%) isolates with ST239-SCCmecIII, seven (21.9%) isolates with ST5-SCCmecII, six (18.8%) isolates with ST59-SCCmecIV, and two (6.2%) isolates with ST59-SCCmecVT. Two isolates had an MIC of 2 μg/mL and were identified as ST239-SCCmecIII. No statistically significant change in the distribution of MICs of all isolates was observed between 2003 and 2014 (p = 0.263). There was no significant difference in the mortality rates between two groups of patients with vancomycin MICs < 2 μg/mL and ≥ 2 μg/mL (p = > 0.99).ConclusionThere was no vancomycin MIC creep in the period from 2003 to 2014 in this study. Appropriate prognostic models for assessment of the association among sequence types, vancomycin MICs, and clinical outcome warrant further investigation

Learning to Compose Representations of Different Encoder Layers towards Improving Compositional Generalization

Recent studies have shown that sequence-to-sequence (seq2seq) models struggle with compositional generalization (CG), i.e., the ability to systematically generalize to unseen compositions of seen components. There is mounting evidence that one of the reasons hindering CG is the representation of the encoder uppermost layer is entangled, i.e., the syntactic and semantic representations of sequences are entangled. However, we consider that the previously identified representation entanglement problem is not comprehensive enough. Additionally, we hypothesize that the source keys and values representations passing into different decoder layers are also entangled. Starting from this intuition, we propose \textsc{CompoSition} (\textbf{Compo}se \textbf{S}yntactic and Semant\textbf{i}c Representa\textbf{tion}s), an extension to seq2seq models which learns to compose representations of different encoder layers dynamically for different tasks, since recent studies reveal that the bottom layers of the Transformer encoder contain more syntactic information and the top ones contain more semantic information. Specifically, we introduce a \textit{composed layer} between the encoder and decoder to compose different encoder layers' representations to generate specific keys and values passing into different decoder layers. \textsc{CompoSition} achieves competitive results on two comprehensive and realistic benchmarks, which empirically demonstrates the effectiveness of our proposal. Codes are available at~\url{https://github.com/thinkaboutzero/COMPOSITION}.Comment: Accepted by Findings of EMNLP 202