A Multi-Plane Block-Coordinate Frank-Wolfe Algorithm for Training Structural SVMs with a Costly max-Oracle

Structural support vector machines (SSVMs) are amongst the best performing models for structured computer vision tasks, such as semantic image segmentation or human pose estimation. Training SSVMs, however, is computationally costly, because it requires repeated calls to a structured prediction subroutine (called \emph{max-oracle}), which has to solve an optimization problem itself, e.g. a graph cut. In this work, we introduce a new algorithm for SSVM training that is more efficient than earlier techniques when the max-oracle is computationally expensive, as it is frequently the case in computer vision tasks. The main idea is to (i) combine the recent stochastic Block-Coordinate Frank-Wolfe algorithm with efficient hyperplane caching, and (ii) use an automatic selection rule for deciding whether to call the exact max-oracle or to rely on an approximate one based on the cached hyperplanes. We show experimentally that this strategy leads to faster convergence to the optimum with respect to the number of requires oracle calls, and that this translates into faster convergence with respect to the total runtime when the max-oracle is slow compared to the other steps of the algorithm. A publicly available C++ implementation is provided at http://pub.ist.ac.at/~vnk/papers/SVM.html

A New Goodness-of-Fit Test for Item Response Theory

Chi-square techniques for testing goodness-of-fit in item response theory are shown to give incorrect results. A new measure, CB, based on cumulants is proposed which avoids the arbitrary nature of interval creation found in chi-square techniques. The distribution of CB is estimated using Monte Carlo techniques and critical values for testing goodness-of-fit are given

Split Inteins: From Mechanistic Studies to Novel Protein Engineering Technologies

Inteins are auto-processing protein domains that carry out a post-translational process known as protein splicing. This process is characterized by excision of the intein (intervening protein) domain from within a larger polypeptide sequence with concomitant ligation of the flanking extein ( external protein) regions through a native peptide bond. Remarkably, a small subset of all inteins are naturally transcribed and translated as two fragments that efficiently associate and carry out the same biochemical process in trans, and these split inteins are potentially powerful tools for protein engineering. Recently, a split intein from the cyanobacterium Nostoc punctiforme (Npu) was discovered that can carry out protein splicing with a half-life of one minute, as opposed to hours as seen for previously characterized split and contiguous inteins. Inspired by the apparent uniqueness of this “ultrafast” splicing activity and its practical implications, we characterized several orthologous split inteins from the same family as Npu. Surprisingly, many of these inteins splice as quickly as Npu, and biochemical characterization of this family divulged sequence-activity correlations that provided insights into the molecular determinants for fast protein trans-splicing. Importantly, several of these inteins are extraordinarily efficient in their first auto-processing step, peptide bond cleavage coupled to thioester formation. Harnessing this property, along with efficient fragment association, a streamlined iteration of Expressed Protein Ligation (EPL), the most prevalent protein semi-synthesis technique, was developed. Further insights into protein splicing were obtained by the development of a novel kinetic assay that allowed for quantitative observation of a crucial intermediate in the protein splicing pathway, the branched intermediate (BI). Using this assay, BI resolution was unambiguously identified as the rate limiting step for Npu splicing. Furthermore, the roles of extein residues in individual steps along the splicing pathway were teased apart. Using protein semi-synthesis, kinetic measurements, and structural techniques, C-extein composition was found to be intimately linked to active-site dynamics and BI resolution kinetics. In addition to chemical reactivity, the fragment assembly of Npu was also characterized. Mutation of charged residues at the binding interface demonstrated that split intein binding affinity was dominated by intermolecular electrostatic interactions. By swapping charged residues between the intein fragments, a new split intein was engineered with orthogonal binding and reactivity to the wild-type Npu split intein. The wild-type and charges wapped inteins could be used in protein semi-synthesis endeavors requiring parallel selective splicing reactions in one pot. Finally, using a combination of biophysical techniques, the mechanism of split intein assembly was elucidated. Our analyses indicated that the assembly follows a unique trajectory comprised of coupled binding and folding of disordered regions of each fragment followed by a collapse of the structure into a stable functional domain. Collectively, these structural and functional studies not only provide insights into the inner workings of inteins but will also continue to aid in the development of important protein engineering technologies

Functional requirements for onboard management of space shuttle consumables, volume 1

A study was conducted to determine the functional requirements for onboard management of space shuttle consumables. A generalized consumable management concept was developed for application to advanced spacecraft. The subsystems and related consumables selected for inclusion in the consumables management system are: (1) propulsion, (2) power generation, and (3) environmental and life support

Spacelab simulation using a Lear Jet aircraft: Mission no. 4 (ASSESS program)

The fourth ASSESS Spacelab simulation mission utilizing a Lear Jet aircraft featured trained experiment operators (EOs) in place of the participating scientists, to simulate the role and functions of payload specialists in Spacelab who may conduct experiments developed by other scientists. The experiment was a broadband infrared photometer coupled to a 30-cm, open port, IR telescope. No compromises in equipment design or target selection were made to simplify operator tasks; the science goals of the mission were selected to advance the mainline research program of the principle investigator (PI). Training of the EOs was the responsibility of the PI team and consisted of laboratory sessions, on-site training during experiment integration, and integrated mission training using the aircraft as a high-fidelity simulator. The EO permission experience in these several disciplines proved adequate for normal experiment operations, but marginal for the identification and remedy of equipment malfunctions. During the mission, the PI utilized a TV communication system to assist the EOs to overcome equipment difficulties; both science and operations were successfully implemented

Shuttle spacelab simulation using a Lear jet aircraft: Mission no. 3 (ASSESS program)

The third ASSESS mission using a Lear Jet aircraft conducted to continue the study of scientific experiment operations in a simulated Spacelab environment. Prior to the mission, research planning and equipment preparation were observed and documented. A flight readiness review for the experiment was conducted. Nine of the ten scheduled flights were completed during simulation mission and all major science objectives were accomplished. The equipment was well qualified for flight and gave little trouble; telescope malfunctions occurred early in the mission and were corrected. Both real-time and post-observation data evaluation were used to assess research progress and to plan subsequent flight observations for maximum effectiveness

A Sound Idea: A Theory-Based Synthesis and Explanadum Supporting the Use of Music in Marketing Strategy

A review and synthesis of research literature regarding the role and influence of music on advertising effectiveness and in-store shopper moods and behavior is presented. A conceptual model is presented, with strong theoretical support found in classical conditioning, information processing, involvement, and mood states literature. The authors posit that a retailer should use a dual, concomitant music strategy as a component of an overall advertising and in-store marketing promotion plan. This strategy is presented in what the authors refer to as the Music Affect Model. While using the positive affects of music on consumer purchasing behavior as its core source of potency, the proposed strategy should likely lead to enhanced sales outcomes

Improving The Impact Of Cause-Related Donation Exchanges Through Message Framing: A Conceptual Perspective

A conceptual framework is presented in support of a cause-related exchange model. Of interest is the possible effect of message framing on the likelihood of participating in a cause-related donation exchange. Framing the cause related marketing message concretely or abstractly, in regard to the dollar amount or percentage level of a cause-related purchase that will actually go to a designated cause, is posited to directly impact the likelihood of participating in a donation exchange. Furthermore, the level of cause support and the level of donation request are posited to mutually moderate the above-mentioned relationship. The cause support level is presented to have a central role, influencing both the effects of message framing on the likelihood of participating in a donation exchange and the level of donation request on the likelihood of participating in a donation exchange.  It is the authors’ intention that the presentation of this conceptual model will contribute to cause-related research literature, and concomitantly, attract practitioner interest as well

Role of cardiopulmonary interactions in development of ventilator-induced lung injury-Experimental evidence and clinical implications

Ventilator-induced lung injury (VILI) impacts outcomes in ARDS and optimization of ventilatory strategies improves survival. Decades of research has identified various mechanisms of VILI, largely focusing on airspace forces of plateau pressure, tidal volume and driving pressure. Experimental evidence indicates the role of adverse cardiopulmonary interaction during mechanical ventilation, contributing to VILI genesis mostly by modulating pulmonary vascular dynamics. Under passive mechanical ventilation, high transpulmonary pressure increases afterload on right heart while high pleural pressure reduces the RV preload. Together, they can result in swings of pulmonary vascular flow and pressure. Altered vascular flow and pressure result in increased vascular shearing and wall tension, in turn causing direct microvascular injury accompanied with permeability to water, proteins and cells. Moreover, abrupt decreases in airway pressure, may result in sudden overperfusion of the lung and result in similar microvascular injury, especially when the endothelium is stretched or primed at high positive end-expiratory pressure. Microvascular injury is universal in VILI models and presumed in the diagnosis of ARDS; preventing such microvascular injury can reduce VILI and impact outcomes in ARDS. Consequently, developing cardiovascular targets to reduce macro and microvascular stressors in the pulmonary circulation can potentially reduce VILI. This paper reviews the role of cardiopulmonary interaction in VILI genesis

Phenytoin Interaction with Enteral Feedings Administered through Nasogastric Tubes

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142072/1/jpen0513.pd