A Split by Any Other Name ...

We applaud the contribution that the Commission on Structural Alternatives for the Federal Courts of Appeals (White Commission) has made to the public debate regarding how the federal courts of appeals can cope with the demands of ever increasing caseloads and no new judicial resources. The White Commission has conscientiously discharged its challenging assignment in the very brief period which Congress allotted. We believe, however, that a careful review of the Commission\u27s research reveals no significant evidence of dysfunction in any court of appeals, and certainly none sufficiently severe to warrant its ultimate recommendation to restructure the Ninth Circuit Court of Appeals into three autonomous adjudicative divisions. We submit that the Commission has not met its burden of persuasion for such sweeping change. Therefore, we urge Congress to authorize the Ninth Circuit, which has been the acknowledged national leader in experimenting with innovative methods of resolving large caseloads, to continue and expand upon that record of successful experimentation. In this article, we suggest that those who propose to change a successful, century-old institution must bear the burden of persuasion regarding the need for modification. In the first section of this article, we explore some of the principal concerns that the members of the Commission, as well as certain observers of the Ninth Circuit, have raised during the study process. In the second section, we show that, by standard measures of judicial administration and performance, the Ninth Circuit Court of Appeals is operating as well as or better than the other courts of appeals which were not the focus of the White Commission\u27s recommendations. The next section reviews how the untested restructuring proposed by the Commission will cause more problems than it was intended to fix. Finally, in the fourth section, we offer a constructive alternative approach that the Ninth Circuit has already implemented. We examine the work of the Ninth Circuit\u27s Evaluation Committee, which is developing innovative solutions to address many of the same concerns that the Commission sought to alleviate through its restructuring proposal. Through more modest modifications to court operations, the Ninth Circuit will be able to maintain its flexibility and adaptability in order to meet the caseload demands of the next millennium. We conclude by suggesting that Congress authorize the Ninth Circuit to continue experimenting with measures that promise to enhance court operations

System Level Synthesis Beyond Finite Impulse Response Using Approximation by Simple Poles

Optimal linear feedback control design is valuable but challenging. The system level synthesis approach uses a reparameterization to expand the class of problems that can be solved using convex reformulations, among other benefits. However, to solve system level synthesis problems prior work relies on finite impulse response approximations that lead to deadbeat control, and that can experience infeasibility and increased suboptimality, especially in systems with large separation of time scales. This work develops a new technique by combining system level synthesis with a new approximation based on simple poles. The result is a new design method which does not result in deadbeat control, is convex and tractable, always feasible, can incorporate prior knowledge, and works well for systems with large separation of time scales. A general suboptimality result is provided which bounds the approximation error based on the geometry of the pole selection. The bound is then specialized to a particularly interesting pole selection to obtain a non-asymptotic convergence rate. An example demonstrates superior performance of the method.Comment: 25 page

Motor Adaptations to Pain during a Bilateral Plantarflexion Task: Does the Cost of Using the Non-Painful Limb Matter?

During a force-matched bilateral task, when pain is induced in one limb, a shift of load to the non-painful leg is classically observed. This study aimed to test the hypothesis that this adaptation to pain depends on the mechanical efficiency of the non-painful leg. We studied a bilateral plantarflexion task that allowed flexibility in the relative force produced with each leg, but constrained the sum of forces from both legs to match a target. We manipulated the mechanical efficiency of the non-painful leg by imposing scaling factors: 1, 0.75, or 0.25 to decrease mechanical efficiency (Decreased efficiency experiment: 18 participants); and 1, 1.33 or 4 to increase mechanical efficiency (Increased efficiency experiment: 17 participants). Participants performed multiple sets of three submaximal bilateral isometric plantarflexions with each scaling factor during two conditions (Baseline and Pain). Pain was induced by injection of hypertonic saline into the soleus. Force was equally distributed between legs during the Baseline contractions (laterality index was close to 1; Decreased efficiency experiment: 1.16±0.33; Increased efficiency experiment: 1.11±0.32), with no significant effect of Scaling factor. The laterality index was affected by Pain such that the painful leg contributed less than the non-painful leg to the total force (Decreased efficiency experiment: 0.90±0.41, P<0.001; Increased efficiency experiment: 0.75±0.32, P<0.001), regardless of the efficiency (scaling factor) of the non-painful leg. When compared to the force produced during Baseline of the corresponding scaling condition, a decrease in force produced by the painful leg was observed for all conditions, except for scaling 0.25. This decrease in force was correlated with a decrease in drive to the soleus muscle. These data highlight that regardless of the overall mechanical cost, the nervous system appears to prefer to alter force sharing between limbs such that force produced by the painful leg is reduced relative to the non-painful leg

Influence of experimental pain on the perception of action capabilities and performance of a maximal single-leg hop

Changes in an individual's state - for example, anxiety/chronic pain - can modify the perception of action capabilities and physical task requirements. In parallel, considerable literature supports altered motor performance during both acute and chronic pain. This study aimed to determine the effect of experimental pain on perception of action capabilities and performance of a dynamic motor task. Performance estimates and actual performance of maximal single-leg hops were recorded for both legs in 13 healthy participants before, during, and after an episode of acute pain induced by a single bolus injection of hypertonic saline into vastus lateralis of 1 leg, with the side counterbalanced among participants. Both estimation of performance and actual performance were smaller (

Predicting the Risk and Trajectory of Intensive Care Patients Using Survival Models

SM thesisUsing artificial intelligence to assist physicians in patient care has received sustained interest over the past several decades. Recently, with automated systems at most bedsides, the amount of patient information collected continues to increase, providing specific impetus for intelligent systems that can interpret this information. In fact, the large set of sensors and test results, often measured repeatedly over long periods of time, make it challenging for caregivers to quickly utilize all of the data for optimal patient treatment.This research focuses on predicting the survival of ICU patients throughout their stay. Unlike traditional static mortality models, this survival prediction is explored as an indicator of patient state and trajectory. Using survival analysis techniques and machine learning, models are constructed that predict individual patient survival probabilities at fixed intervals in the future. These models seek to help physicians interpret the large amount of data available in order to provide optimal patient care.We find that the survival predictions from our models are comparable to survival predictions using the SAPS score, but are available throughout the patient's ICU course instead of only at 24 hours after admission. Additionally, we demonstrate effective prediction of patient mortality over fixed windows in the future

Crystal structure of Caulobacter crescentus polynucleotide phosphorylase reveals a mechanism of RNA substrate channelling and RNA degradosome assembly

Polynucleotide phosphorylase (PNPase) is an exoribonuclease that cleaves single-stranded RNA substrates with 3′–5′ directionality and processive behaviour. Its ring-like, trimeric architecture creates a central channel where phosphorolytic active sites reside. One face of the ring is decorated with RNA-binding K-homology (KH) and S1 domains, but exactly how these domains help to direct the 3′ end of single-stranded RNA substrates towards the active sites is an unsolved puzzle. Insight into this process is provided by our crystal structures of RNA-bound and apo Caulobacter crescentus PNPase. In the RNA-free form, the S1 domains adopt a ‘splayed’ conformation that may facilitate capture of RNA substrates. In the RNA-bound structure, the three KH domains collectively close upon the RNA and direct the 3′ end towards a constricted aperture at the entrance of the central channel. The KH domains make non-equivalent interactions with the RNA, and there is a marked asymmetry within the catalytic core of the enzyme. On the basis of these data, we propose that structural non-equivalence, induced upon RNA binding, helps to channel substrate to the active sites through mechanical ratcheting. Structural and biochemical analyses also reveal the basis for PNPase association with RNase E in the multi-enzyme RNA degradosome assembly of the α-proteobacteria

Predicting the risk and trajectory of intensive care patients using survival models

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (p. 119-126).Using artificial intelligence to assist physicians in patient care has received sustained interest over the past several decades. Recently, with automated systems at most bedsides, the amount of patient information collected continues to increase, providing specific impetus for intelligent systems that can interpret this information. In fact, the large set of sensors and test results, often measured repeatedly over long periods of time, make it challenging for caregivers to quickly utilize all of the data for optimal patient treatment. This research focuses on predicting the survival of ICU patients throughout their stay. Unlike traditional static mortality models, this survival prediction is explored as an indicator of patient state and trajectory. Using survival analysis techniques and machine learning, models are constructed that predict individual patient survival probabilities at fixed intervals in the future. These models seek to help physicians interpret the large amount of data available in order to provide optimal patient care. We find that the survival predictions from our models are comparable to survival predictions using the SAPS score, but are available throughout the patient's ICU course instead of only at 24 hours after admission. Additionally, we demonstrate effective prediction of patient mortality over fixed windows in the future.by Caleb W. Hug.S.M

Detecting hazardous intensive care patient episodes using real-time mortality models

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 229-237).The modern intensive care unit (ICU) has become a complex, expensive, data-intensive environment. Caregivers maintain an overall assessment of their patients based on important observations and trends. If an advanced monitoring system could also reliably provide a systemic interpretation of a patient's observations it could help caregivers interpret these data more rapidly and perhaps more accurately. In this thesis I use retrospective analysis of mixed medical/surgical intensive care patients to develop predictive models. Logistic regression is applied to 7048 development patients with several hundred candidate variables. These candidate variables range from simple vitals to long term trends and baseline deviations. Final models are selected by backward elimination on top cross-validated variables and validated on 3018 additional patients. The real-time acuity score (RAS) that I develop demonstrates strong discrimination ability for patient mortality, with an ROC area (AUC) of 0.880. The final model includes a number of variables known to be associated with mortality, but also computationally intensive variables absent in other severity scores. In addition to RAS, I also develop secondary outcome models that perform well at predicting pressor weaning (AUC=0.825), intraaortic balloon pump removal (AUC=0.816), the onset of septic shock (AUC=0.843), and acute kidney injury (AUC=0.742). Real-time mortality prediction is a feasible way to provide continuous risk assessment for ICU patients. RAS offers similar discrimination ability when compared to models computed once per day, based on aggregate data over that day.(cont.) Moreover, RAS mortality predictions are better at discrimination than a customized SAPS II score (Day 3 AUC=0.878 vs AUC=0.849, p < 0.05). The secondary outcome models also provide interesting insights into patient responses to care and patient risk profiles. While models trained for specifically recognizing secondary outcomes consistently outperform the RAS model at their specific tasks, RAS provides useful baseline risk estimates throughout these events and in some cases offers a notable level of predictive utility.by Caleb Wayne Hug.Ph.D

Experimental measurement of stress at a four-domain junction in lead zirconate titanate

A junction between two lamellar bands of ferroelectric domains in a lead zirconate titanate (PZT) ceramic is analysed using Kikuchi diffraction patterns in the transmission electron microscope. Indexing of the diffraction patterns allowed the determination of the 3D relative orientation of the 4 different domains at the junction and thus the characterisation of the domain boundaries. The local c/a ratio could also be determined from the misorientations at the domain boundaries. Analysis of the data showed that large stresses were concentrated at the junction, and that this is inevitable at such band junctions. Such stress concentrations could act as nuclei for cracking of the ceramic under additional loading in service, perhaps particularly as a consequence of extended electromechanical cycling. Moreover, the stresses would increase with increasing c/a making the issues all the more serious for Ti-rich compositions having larger c/a ratios