Fabrication of Embedded Microvalve on PMMA Microfluidic Devices through Surface Functionalization

The integration of a PDMS membrane within orthogonally placed PMMA microfluidic channels enables the pneumatic actuation of valves within bonded PMMA-PDMS-PMMA multilayer devices. Here, surface functionalization of PMMA substrates via acid catalyzed hydrolysis and air plasma corona treatment were investigated as possible techniques to permanently bond PMMA microfluidic channels to PDMS surfaces. FTIR and water contact angle analysis of functionalized PMMA substrates showed that air plasma corona treatment was most effective in inducing PMMA hydrophilicity. Subsequent fluidic tests showed that air plasma modified and bonded PMMA multilayer devices could withstand fluid pressure at an operational flow rate of 9 mircoliters/min. The pneumatic actuation of the embedded PDMS membrane was observed through optical microscopy and an electrical resistance based technique. PDMS membrane actuation occurred at pneumatic pressures of as low as 10kPa and complete valving occurred at 14kPa for 100 micrometers x 100 micrometers channel cross-sections.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Are Credit-Card Late Fees Interest ? Delineating the Preemptive Reach of Section 85 of the National Bank Act of 1864 and Section 521 of the Depositary Institutions Deregulation and Monetary Control Act of 1980

This Note argues that neither section 85 of the NBA nor section 521 of the DIDA preempts state consumer-credit-protection laws regulating late fees on credit-card transactions. Part I discusses the three approaches that the Supreme Court has devised and used over the years to determine when a federal law preempts state law: express preemption, implied preemption, and conflict preemption. Part II applies express preemption analysis and asserts that the ordinary meaning of DIDA section 521\u27s express preemption language does not evince Congress\u27s intent to preempt state prohibitions of late fees. Part III applies implied preemption analysis and argues that neither NBA section 85 nor DIDA section 521 impliedly preempts state laws regulating late fees because Congress did not indicate a clear and manifest purpose to preempt the entire field of consumer-credit protection. Finally, Part IV applies conflict preemption analysis and argues that sustaining state law provisions governing late fees, which are imposed only on contingent occasions of borrower default, does not conflict with the congressional objective in enacting NBA section 85 and DIDA section 521-- achieving lender parity

Teaching writing to students from Asia: linking approach and motivation

This article is based on a study of the motivation and perceived outcomes of students from non-English speaking backgrounds enrolled in the English for Academic Study program at the Auckland University of Technology. It discusses the implications of the findings for tutors responsible for teaching writing. The findings indicate that that the motivation and immediate needs of those students are mainly instrumental, to write assignments and projects in a university environment, while the long-term goals are to use language in the workplace. For such students, we argue that a writing program will need to cater for generic forms acceptable to academic as well as real (often business) world readership. We also argue that while introducing an element of ideological critique is important when teaching writing, it does not seem to immediately help students with actual use or application of the genres relevant in real world situations. However, when considering long-term goals, the article looks at how the work of academic literacies thinkers can help alert students to power and ideological aspects of writing. The discussion in this article could also be generalized for the teaching of writing in ESL and EFL contexts

A multiple-cut analytic center cutting plane method for semidefinite feasibility problems

10.1137/S1052623400370503SIAM Journal on Optimization1241126-114

Transporting audio over wireless ad hoc networks: Experiments & new insights

Current efforts on ad hoc wireless network research are focused more on routing and multicasting protocols. However, there is an increasing need to understand what sort of media could be transported over wireless ad hoc networks other than data. Existing research on multimedia wireless communications often addresses broadband wireless networks with a connection-oriented backbone. In this paper, we address the possibility of transporting audio traffic over wireless ad hoc networks. We examine the impact of wireless multi-hop links on audio data relay and how the audio quality at the receiver is affected. In particular, we examine communication parameters such as latency, jitter, packet loss, and their impact on perceived audio quality. ©2003 IEEE.published_or_final_versio

Variance Estimation in Inverse Probability Weighted Cox Models

Inverse probability weighted Cox models can be used to estimate marginal hazard ratios under different treatments interventions in observational studies. To obtain variance estimates, the robust sandwich variance estimator is often recommended to account for the induced correlation among weighted observations. However, this estimator does not incorporate the uncertainty in estimating the weights and tends to overestimate the variance, leading to inefficient inference. Here we propose a new variance estimator that combines the estimation procedures for the hazard ratio and weights using stacked estimating equations, with additional adjustments for the sum of non-independent and identically distributed terms in a Cox partial likelihood score equation. We prove analytically that the robust sandwich variance estimator is conservative and establish the asymptotic equivalence between the proposed variance estimator and one obtained through linearization by Hajage et al., 2018. In addition, we extend our proposed variance estimator to accommodate clustered data. We compare the finite sample performance of the proposed method with alternative methods through simulation studies. We illustrate these different variance methods in an inverse probability weighted application to estimate the marginal hazard ratio for postoperative hospitalization under sleeve gastrectomy versus Roux-en-Y gastric bypass in a large medical claims and billing database. To facilitate implementation of the proposed method, we have developed an R package ipwCoxCSV

Role of Interleukin 17 in arthritis chronicity through survival of synoviocytes via regulation of synoviolin expression

Background: The use of TNF inhibitors has been a major progress in the treatment of chronic inflammation. However, not all patients respond. In addition, response will be often lost when treatment is stopped. These clinical aspects indicate that other cytokines might be involved and we focus here on the role of IL-17. In addition, the chronic nature of joint inflammation may contribute to reduced response and enhanced chronicity. Therefore we studied the capacity of IL-17 to regulate synoviolin, an E3 ubiquitin ligase implicated in synovial hyperplasia in human rheumatoid arthritis (RA) FLS and in chronic reactivated streptococcal cell wall (SCW)-induced arthritis.<p></p> Methodology/Principal Findings: Chronic reactivated SCW-induced arthritis was examined in IL-17R deficient and wild-type mice. Synoviolin expression was analysed by real-time RT-PCR, Western Blot or immunostaining in RA FLS and tissue, and p53 assessed by Western Blot. Apoptosis was detected by annexin V/propidium iodide staining, SS DNA apoptosis ELISA kit or TUNEL staining and proliferation by PCNA staining. IL-17 receptor A (IL-17RA), IL-17 receptor C (IL-17-RC) or synoviolin inhibition were achieved by small interfering RNA (siRNA) or neutralizing antibodies. IL-17 induced sustained synoviolin expression in RA FLS. Sodium nitroprusside (SNP)-induced RA FLS apoptosis was associated with reduced synoviolin expression and was rescued by IL-17 treatment with a corresponding increase in synoviolin expression. IL-17RC or IL-17RA RNA interference increased SNP-induced apoptosis, and decreased IL-17-induced synoviolin. IL-17 rescued RA FLS from apoptosis induced by synoviolin knockdown. IL-17 and TNF had additive effects on synoviolin expression and protection against apoptosis induced by synoviolin knowndown. In IL-17R deficient mice, a decrease in arthritis severity was characterized by increased synovial apoptosis, reduced proliferation and a marked reduction in synoviolin expression. A distinct absence of synoviolin expressing germinal centres in IL-17R deficient mice contrasted with synoviolin positive B cells and Th17 cells in synovial germinal centre-like structures.<p></p> Conclusion/Significance: IL-17 induction of synoviolin may contribute at least in part to RA chronicity by prolonging the survival of RA FLS and immune cells in germinal centre reactions. These results extend the role of IL-17 to synovial hyperplasia.<p></p&gt

Maritime continent seasonal climate biases in AMIP experiments of the CMIP5 multimodel ensemble

The fidelity of 28 Coupled Model Intercomparison Project phase 5 (CMIP5) models in simulating mean climate over the Maritime Continent in the Atmospheric Model Intercomparison Project (AMIP) experiment is evaluated in this study. The performance of AMIP models varies greatly in reproducing seasonal mean climate and the seasonal cycle. The multi-model mean has better skill at reproducing the observed mean climate than the individual models. The spatial pattern of 850 hPa wind is better simulated than the precipitation in all four seasons. We found that model horizontal resolution is not a good indicator of model performance. Instead, a model’s local Maritime Continent biases are somewhat related to its biases in the local Hadley circulation and global monsoon. The comparison with coupled models in CMIP5 shows that AMIP models generally performed better than coupled models in the simulation of the global monsoon and local Hadley circulation but less well at simulating the Maritime Continent annual cycle of precipitation. To characterize model systematic biases in the AMIP runs, we performed cluster analysis on Maritime Continent annual cycle precipitation. Our analysis resulted in two distinct clusters. Cluster I models are able to capture both the winter monsoon and summer monsoon shift, but they overestimate the precipitation; especially during the JJA and SON seasons. Cluster II models simulate weaker seasonal migration than observed, and the maximum rainfall position stays closer to the equator throughout the year. The tropics-wide properties of these clusters suggest a connection between the skill of simulating global properties of the monsoon circulation and the skill of simulating the regional scale of Maritime Continent precipitation

Smooth-muscle-associated contractile protein in renal mesenchymal tumour cells and in transformed cells from DMN-injected rats.

Cryostat sections and established in vitro cultures of dimethylnitrosamine(DMN)-induced renal mesenchymal tumours and monolayer cultures of transformed kidney cells derived from rats treated with a carcinogenic dose of DMN were examined by indirect immunofluorescence with human serum containing smooth muscle antibody. Eight mesenchymal tumours examined showed filamentous cytoplasmic staining of spindle cells infiltrating between renal tubules, whilst in normal kidneys interstitial cells were only weakly positive. In established in vitro cultures from 6 mesenchymal tumours, different patterns of staining were observed in morphologically different cell forms, ranging from fine filamentous staining in giant cells to diffuse cytoplasmic fluorescence in small bipolar cells, and cell outline staining in polygonal cells. In addition filamentous staining of microvillous projections and nucleolar staining were observed in some tumour cells. Monolayer cultures of transformed kidney cells showed strong staining of coarse, randomly-orientated cytoplasmic filaments, whilst fibroblasts cultured from normal rat kidney demonstrated an ordered array of fine, parallel filaments. Specificity of the immunofluorescent staining reaction was established by failure to obtain staining with normal serum, with smooth muscle antibody serum neutralized by homogenates of smooth muscle or extracts containing actin derived from smooth muscle. These results indicate that there is an apparent increase of actin-like contractile microfilaments in transformed cells and in renal mesenchymal tumours. The cytoplasmic contracile microfilaments in these cells may play a role in tumour cell mobility and invasion