Decision-to-incision times and maternal and infant outcomes.

Journal ArticleOBJECTIVE: To measure decision-to-incision intervals and related maternal and neonatal outcomes in a cohort of women undergoing emergency cesarean deliveries at multiple university-based hospitals comprising the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. METHODS: All women undergoing a primary cesarean delivery at a Network center during a 2-year time span were prospectively ascertained. Emergency procedures were defined as those performed for umbilical cord prolapse, placental abruption, placenta previa with hemorrhage, nonreassuring fetal heart rate pattern, or uterine rupture. Detailed information regarding maternal and neonatal outcomes, including the interval from the decision time to perform cesarean delivery to the actual skin incision, was collected. RESULTS: Of the 11,481 primary cesarean deliveries, 2,808 were performed for an emergency indication. Of these, 1,814 (65%) began within 30 minutes of the decision to operate. Maternal complication rates, including endometritis, wound infection, and operative injury, were not related to the decision-to-incision interval. Measures of newborn compromise including umbilical artery pH less than 7 and intubation in the delivery room were significantly greater when the cesarean delivery was commenced within 30 minutes, likely attesting to the need for expedited delivery. Of the infants with indications for an emergency cesarean delivery who were delivered more than 30 minutes after the decision to operate, 95% did not experience a measure of newborn compromise. CONCLUSION: Approximately one third of primary cesarean deliveries performed for emergency indications are commenced more than 30 minutes after the decision to operate, and the majority were for nonreassuring heart rate tracings. In these cases, adverse neonatal outcomes were not increased. LEVEL OF EVIDENCE: II-2

Njihanje i upravljanje stabilnošću koturajućeg Acrobota

In this paper the Wheeled Acrobot (WAcrobot), a novel mechanical system consisting of an underactuated double inverted pendulum robot (Acrobot) equipped with actuated wheels, is described. This underactuated and highly nonlinear system has potential applications in mobile manipulators and leg-wheeled robots. It is also a testbed for researchers studying advanced methodologies in nonlinear control. The control system for swing-up of the WAcrobot based on collocated or non-collocated feedback linearisation to linearise the active or passive Degree Of Freedom (DOF) followed by Linear Quadratic Regulator (LQR) to stabilise the robot is discussed. The effectiveness of the proposed scheme is validated with numerical simulation. The numerical results are visualised by graphical simulation to demonstrate the correlation between the numerical results and the WAcrobot physical response.U članku je opisan koturajući Acrobot (WAcrobot), novi mehanički sustav koji se sastoji od podupravljanog robota u obliku dvostrukog inverznog njihala (Acrobot) opremljenog s aktuiranim kotačem. Ovaj podupravljani i izrazito nelinearni sustav ima potencijalnu primjenu u mobilnim manipulatorima i robotima na kotačima. Također služi kao testni model za istraživače koji proučavaju napredne metode nelinearnog upravljanja. U radu je opisan sustav upravljanja za podizanje WAcrobot-a u ispravan položaj baziran na metodama kolocirane i nekolocirane eksterne linearizacije za linearizaciju aktivnog ili pasivnog stupnja slobode, i linearnom kvadratičnom regulatoru za stabilizaciju robota. Učinkovitost predvi.ene metode je validirana simulacijskim rezultatima. Rezultati su prikazani u obliku animacije kako bi se demonstrirala korelacija izme.u simulacijskih odziva i fizičkog odziva WAcrobota-a

The Binding of Learning to Action in Motor Adaptation

In motor tasks, errors between planned and actual movements generally result in adaptive changes which reduce the occurrence of similar errors in the future. It has commonly been assumed that the motor adaptation arising from an error occurring on a particular movement is specifically associated with the motion that was planned. Here we show that this is not the case. Instead, we demonstrate the binding of the adaptation arising from an error on a particular trial to the motion experienced on that same trial. The formation of this association means that future movements planned to resemble the motion experienced on a given trial benefit maximally from the adaptation arising from it. This reflects the idea that actual rather than planned motions are assigned ‘credit’ for motor errors because, in a computational sense, the maximal adaptive response would be associated with the condition credited with the error. We studied this process by examining the patterns of generalization associated with motor adaptation to novel dynamic environments during reaching arm movements in humans. We found that these patterns consistently matched those predicted by adaptation associated with the actual rather than the planned motion, with maximal generalization observed where actual motions were clustered. We followed up these findings by showing that a novel training procedure designed to leverage this newfound understanding of the binding of learning to action, can improve adaptation rates by greater than 50%. Our results provide a mechanistic framework for understanding the effects of partial assistance and error augmentation during neurologic rehabilitation, and they suggest ways to optimize their use.Alfred P. Sloan FoundationMcKnight Endowment Fund for Neuroscienc

Effects of Ethanol and NAP on Cerebellar Expression of the Neural Cell Adhesion Molecule L1

The neural cell adhesion molecule L1 is critical for brain development and plays a role in learning and memory in the adult. Ethanol inhibits L1-mediated cell adhesion and neurite outgrowth in cerebellar granule neurons (CGNs), and these actions might underlie the cerebellar dysmorphology of fetal alcohol spectrum disorders. The peptide NAP potently blocks ethanol inhibition of L1 adhesion and prevents ethanol teratogenesis. We used quantitative RT-PCR and Western blotting of extracts of cerebellar slices, CGNs, and astrocytes from postnatal day 7 (PD7) rats to investigate whether ethanol and NAP act in part by regulating the expression of L1. Treatment of cerebellar slices with 20 mM ethanol, 10−12 M NAP, or both for 4 hours, 24 hours, and 10 days did not significantly affect L1 mRNA and protein levels. Similar treatment for 4 or 24 hours did not regulate L1 expression in primary cultures of CGNs and astrocytes, the predominant cerebellar cell types. Because ethanol also damages the adult cerebellum, we studied the effects of chronic ethanol exposure in adult rats. One year of binge drinking did not alter L1 gene and protein expression in extracts from whole cerebellum. Thus, ethanol does not alter L1 expression in the developing or adult cerebellum; more likely, ethanol disrupts L1 function by modifying its conformation and signaling. Likewise, NAP antagonizes the actions of ethanol without altering L1 expression