175 research outputs found

    Effect of Palladium Thickness and Extended Isothermal Aging on the Reliability of Solder Interconnects Formed on ENEPIG Surface Finish

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    Surface finishes for copper on printed wiring boards play an important role in the reliability of electrical interconnects. Electroless Nickel/Electroless Palladium/Immersion Gold (ENEPIG), developed in the mid-1990s to alleviate the "black-pad" problem created by Electroless Nickel/Immersion Gold (ENIG) surface finish, has gained interest for critical system applications. This thesis investigates the effect of palladium layer thickness and extended isothermal aging on the reliability of both tin-lead and tin silver copper solder interconnects under temperature cycling, vibration cycling, and drop loading conditions. Chip array ball grid array (CABGA) packages soldered onto ENEPIG-finished PCBs are subjected to the three previously listed conditions. Reliability and failure analyses are conducted to determine the overall effect of palladium layer thickness and isothermal aging on the reliability of these solder interconnects

    MicroRNA-122-dependent and -independent replication of Hepatitis C Virus in Hep3B human hepatoma cells

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    AbstractThe study of Hepatitis C Virus (HCV) has benefitted from the use of the Huh7 cell culture system, but until recently there were no other widely used alternatives to this cell line. Here we render another human hepatoma cell line, Hep3B, permissive to the complete virus life cycle by supplementation with the liver-specific microRNA miR-122, known to aid HCV RNA accumulation. When supplemented, Hep3B cells produce J6/JFH-1 virus titres indistinguishable from those produced by Huh7.5 cells. Interestingly, we were able to detect and characterize miR-122-independent replication of di-cistronic replicons in Hep3B cells. Further, we show that Argonaute-2 (Ago2) is required for miR-122-dependent replication, but dispensable for miR-122-independent replication, confirming Ago2's role in mediating the activity of miR-122. Thus Hep3B cells are a model system for the study of HCV, and miR-122 independent replication is a model to identify proteins involved in the function of miR-122

    Towards Standardized, Safe and Efficacious Screening Approaches to Patients with Lower Extremity Peripheral Arterial Disease in the setting of Lower Extremity Arthroplasty

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    INTRODUCTION: Peripheral arterial disease (PAD) impedes recovery from lower extremity arthroplasties (LEA) and increases risk of complications/mortality, yet there aren’t standards for screening PAD patients pre-LEA. This review proposes some. METHODS: This review searched databases for articles containing relevant terms. Non-English articles, those unrelated to LEA, and duplicates were excluded. Articles were cross-referenced to find other relevant papers for a total of 111. RESULTS: Up to 49.2% of PAD patients have CAD. Wagner grade III/IV ulcers increase amputations and decrease wound closures. The Wound, Ischemia, and Foot Infection (WIfI) system provides more accurate, and therefore actionable, assessment. Overlooking PAD in surgery patients is linked to sequelae from tourniquets. Arterial calcification increases risk of perioperative blood loss from vascular compression, anemia, and critical limb ischemia. Compounding risk factors for PAD (diabetes, smoking, etc.) increase likelihood of future PAD diagnosis. If SBP\u3e180 or DBP\u3e110 mmHg, forgo elective surgery. Non-cardiac surgery patients with hypertension should receive a beta-blocker one day pre-surgery and perioperatively. Smoking cessation four weeks preoperatively and abstinence four weeks postoperatively may halve wound complications. Absent/asymmetrical pulses should prompt vascular referral pre-LEA. ABI may be falsely normal in asymptomatics with moderate aortoiliac stenosis. Risk of hematoma formation and LEA infection suggests waiting one year while continuing antiplatelet therapy. DISCUSSION/CONCLUSIONS: Adequate blood flow is imperative peri- and postoperatively for optimal healing from LEA. Before orthopedic surgery, we suggest meticulous history and assessment to identify PAD risk factors and determine tolerance for surgical intervention. Patients should be stratified for amputation risk and revascularization benefit using the WIfI system. ABI should be performed to assess severity of vascular stenosis. Patients \u3c0.9 should receive vascular consultation, then reassessment. These recommendations could help clinicians assign vascular intervention pre-LEA, minimize complications/reoperations, truncate spending, and improve patient satisfaction/well-being

    Granger causality and transfer entropy are equivalent for Gaussian variables

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    Granger causality is a statistical notion of causal influence based on prediction via vector autoregression. Developed originally in the field of econometrics, it has since found application in a broader arena, particularly in neuroscience. More recently transfer entropy, an information-theoretic measure of time-directed information transfer between jointly dependent processes, has gained traction in a similarly wide field. While it has been recognized that the two concepts must be related, the exact relationship has until now not been formally described. Here we show that for Gaussian variables, Granger causality and transfer entropy are entirely equivalent, thus bridging autoregressive and information-theoretic approaches to data-driven causal inference.Comment: In review, Phys. Rev. Lett., Nov. 200

    Review: The Journal of Dramaturgy, volume 22, issue 2

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    Contents include: Editor\u27s Note; Elliott Hayes Award Acceptance Speech From Denver to Gulu, With Thanks to Lynn Nottage; Learning to Speak American: A Writer\u27s Journey, Keynote Remarks Delivered at the Annual Conference of the Literary Managers and Dramturgs of the Americas, Alliance Theatre, Atlanta, GA June 28, 2012; Michael Mark Chemers\u27 Ghost Light: An Introductory Handbook for Dramaturgy; Creative Process in Theatrical Translation: An Interview with Adam Versenyi; Croisades in Quebec: On the Semiotics of Contemporary French Dramaturgie. Issue editors: Sydney Cheek-O\u27Donnell, Debra Cardona, Janine Sobeckhttps://soundideas.pugetsound.edu/lmdareview/1044/thumbnail.jp

    The CATH domain structure database: new protocols and classification levels give a more comprehensive resource for exploring evolution

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    We report the latest release (version 3.0) of the CATH protein domain database (). There has been a 20% increase in the number of structural domains classified in CATH, up to 86 151 domains. Release 3.0 comprises 1110 fold groups and 2147 homologous superfamilies. To cope with the increases in diverse structural homologues being determined by the structural genomics initiatives, more sensitive methods have been developed for identifying boundaries in multi-domain proteins and for recognising homologues. The CATH classification update is now being driven by an integrated pipeline that links these automated procedures with validation steps, that have been made easier by the provision of information rich web pages summarising comparison scores and relevant links to external sites for each domain being classified. An analysis of the population of domains in the CATH hierarchy and several domain characteristics are presented for version 3.0. We also report an update of the CATH Dictionary of homologous structures (CATH-DHS) which now contains multiple structural alignments, consensus information and functional annotations for 1459 well populated superfamilies in CATH. CATH is directly linked to the Gene3D database which is a projection of CATH structural data onto ∼2 million sequences in completed genomes and UniProt

    Arguing about causes in law: a semi-formal framework for causal arguments

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    In legal argumentation and liability attribution, disputes over causes play a central role. Legal discussions about causation often have difficulty with cause-in-fact in complex situations, e.g. overdetermination, preemption, omission. We first assess three theories of causation. Then we introduce a semi-formal framework to model causal arguments using both strict and defeasible rules. We apply the framework to the Althen vaccine injury case. Wrapping up the paper, we motivate a causal argumentation framework and propose to integrate current theories of causation

    FastBLAST: Homology Relationships for Millions of Proteins

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    BackgroundAll-versus-all BLAST, which searches for homologous pairs of sequences in a database of proteins, is used to identify potential orthologs, to find new protein families, and to provide rapid access to these homology relationships. As DNA sequencing accelerates and data sets grow, all-versus-all BLAST has become computationally demanding.Methodology/principal findingsWe present FastBLAST, a heuristic replacement for all-versus-all BLAST that relies on alignments of proteins to known families, obtained from tools such as PSI-BLAST and HMMer. FastBLAST avoids most of the work of all-versus-all BLAST by taking advantage of these alignments and by clustering similar sequences. FastBLAST runs in two stages: the first stage identifies additional families and aligns them, and the second stage quickly identifies the homologs of a query sequence, based on the alignments of the families, before generating pairwise alignments. On 6.53 million proteins from the non-redundant Genbank database ("NR"), FastBLAST identifies new families 25 times faster than all-versus-all BLAST. Once the first stage is completed, FastBLAST identifies homologs for the average query in less than 5 seconds (8.6 times faster than BLAST) and gives nearly identical results. For hits above 70 bits, FastBLAST identifies 98% of the top 3,250 hits per query.Conclusions/significanceFastBLAST enables research groups that do not have supercomputers to analyze large protein sequence data sets. FastBLAST is open source software and is available at http://microbesonline.org/fastblast
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