655 research outputs found
Review of sensing methodologies for estimation of combustion metrics
For reduction of engine-out emissions and improvement of fuel economy, closed-loop control of the combustion process has been explored and documented by many researchers. In the closed-loop control, the engine control parameters are optimized according to the estimated instantaneous combustion metrics provided by the combustion sensing process. Combustion sensing process is primarily composed of two aspects: combustion response signal acquisition and response signal processing. As a number of different signals have been employed as the response signal and the signal processing techniques can be different, this paper did a review work concerning the two aspects: combustion response signals and signal processing techniques. In-cylinder pressure signal was not investigated as one of the response signals in this paper since it has been studied and documented in many publications and also due to its high cost and inconvenience in the application
Cerium oxide nanoparticle treatment ameliorates peritonitis-induced diaphragm dysfunction
The severe inflammation observed during sepsis is thought to cause diaphragm dysfunction, which is associated with poor patient prognosis. Cerium oxide (CeO2) nanoparticles have been posited to exhibit anti-inflammatory and antioxidative activities suggesting that these particles may be of potential use for the treatment of inflammatory disorders. To investigate this possibility, Sprague Dawley rats were randomly assigned to the following groups: sham control, CeO2 nanoparticle treatment only (0.5 mg/kg iv), sepsis, and sepsis+CeO2 nanoparticles. Sepsis was induced by the introduction of cecal material (600 mg/kg) directly into the peritoneal cavity. Nanoparticle treatment decreased sepsis-associated impairments in diaphragmatic contractile (Po) function (sham: 25.6Âą1.6 N/cm2 vs CeO2: 23.4Âą0.8 N/cm2, vs Sep: 15.9Âą1.0 N/cm2 vs Sep+CeO2: 20.0Âą1.0 N/cm2, P2 nanoparticles may improve diaphragmatic function in the septic laboratory rat
Diabetes Alters Contraction-Induced Mitogen Activated Protein Kinase Activation in the Rat Soleus and Plantaris
The prescription of anaerobic exercise has recently been advocated for the management of diabetes; however exercise-induced signaling in diabetic muscle remains largely unexplored. Evidence from exercise studies in nondiabetics suggests that the extracellular-signal-regulated kinases (Erk1/2), p38, and c-JUN NH2-terminal kinase (Jnk) mitogen-activated protein kinases (MAPKs) are important regulators of muscle adaptation. Here, we compare the basal and the in situ contraction-induced phosphorylation of Erk1/2- p38- and Jnk-MAPK and their downstream targets (p90rsk and MAPKAP-K2) in the plantaris and soleus muscles of normal and obese (fa/fa) Zucker rats. Compared to lean animals, the time course and magnitude of Erk1/2, p90rsk and p38 phosphorylation to a single bout of contractile stimuli were greater in the plantaris of obese animals. Jnk phosphorylation in response to contractile stimuli was muscle-type dependent with greater increases in the plantaris than the soleus. These results suggest that diabetes alters intramuscular signaling processes in response to a contractile stimulus
Predicting the Onset of Cavitation in Automotive Torque ConvertersâPart II: A Generalized Model
The objective of this investigation was to develop a dimensionless model for predicting the
onset of cavitation in torque converters applicable to general converter designs. Dimensional analysis was
applied to test results from a matrix of torque converters that ranged from populations comprised of strict
geometric similitude to those with more relaxed similarities onto inclusion of all the torque converters
tested. Stator torque thresholds at the onset of cavitation for the stall operating condition were experimentally
determined with a dynamometer test cell using nearfield acoustical measurements. Cavitation torques, design
parameters, and operating conditions were resolved into a set of dimensionless quantities for use in the
development of dimensionless empirical models. A systematic relaxation of the fundamental principle of
dimensional analysis, geometric similitude, was undertaken to present empirical models applicable to torque
converter designs of increasingly diverse design parameters. A stepwise linear regression technique coupled
with response surface methodology was utilized to produce an empirical model capable of predicting stator
torque at the onset of cavitation with less than 7% error for general automotive
torque converter designs
Capicua regulates neural stem cell proliferation and lineage specification through control of Ets factors
Capicua (Cic) is a transcriptional repressor mutated in the brain cancer oligodendroglioma. Despite its cancer link, little is known of Cicâs function in the brain. We show that nuclear Cic expression is strongest in astrocytes and neurons but weaker in stem cells and oligodendroglial lineage cells. Using a new conditional Cic knockout mouse, we demonstrate that forebrain-specific Cic deletion increases proliferation and self-renewal of neural stem cells. Furthermore, Cic loss biases neural stem cells toward glial lineage selection, expanding the pool of oligodendrocyte precursor cells (OPCs). These proliferation and lineage effects are dependent on de-repression of Ets transcription factors. In patient-derived oligodendroglioma cells, CIC re-expression or ETV5 blockade decreases lineage bias, proliferation, self-renewal, and tumorigenicity. Our results identify Cic as an important regulator of cell fate in neurodevelopment and oligodendroglioma, and suggest that its loss contributes to oligodendroglioma by promoting proliferation and an OPC-like identity via Ets overactivity
Economic burden of illness of acute coronary syndromes: medical and productivity costs
<p>Abstract</p> <p>Background</p> <p>The significant economic burden associated with acute coronary syndromes (ACS) provides a need to evaluate both medical costs and productivity costs, according to evolving guideline-driven ACS treatment strategies, medical management (MM), percutaneous coronary intervention (PCI), or coronary artery bypass graft (CABG).</p> <p>Methods</p> <p>Commercially insured individuals, aged 18-64, with an emergency room (ER) visit or hospitalization accompanied by an ACS diagnosis (index event) were identified from a large claims database between 01/2004 and 12/2005 with a 1-year follow-up period. Patients who had an ACS diagnosis in the 12 months prior to their index event were excluded. Patients were divided into 3 groups according to treatment strategies during the index event: MM, PCI, or CABG. A subset of patients was identified for the productivity cost analysis exploring short-term disability and absenteeism costs. Multivariate generalized linear models were performed to examine the ACS costs by 3 different treatment strategies.</p> <p>Results</p> <p>A total of 10,487 patients were identified for the medical cost analysis. The total 1-year medical costs (index event costs plus the 1-year follow-up costs) were lowest for MM patients (52,673) and CABG patients (17,335, 6,048, 9,221, $9,460, respectively).</p> <p>Conclusions</p> <p>Both total 1-year medical costs and 1-year productivity costs are substantial for working-aged individuals with ACS. These costs differ according to the type of treatment strategy, with CABG having higher costs compared to either PCI or MM.</p
Mutations in CIC and IDH1 cooperatively regulate 2-hydroxyglutarate levels and cell clonogenicity
The majority of oligodendrogliomas (ODGs) exhibit combined losses of chromosomes 1p and 19q and mutations of isocitrate dehydrogenase (IDH1-R132H or IDH2-R172K). Approximately 70% of ODGs with 1p19q co-deletions harbor somatic mutations in the Capicua Transcriptional Repressor (CIC) gene on chromosome 19q13.2. Here we show that endogenous long (CIC-L) and short (CIC-S) CIC proteins are predominantly localized to the nucleus or cytoplasm, respectively. Cytoplasmic CIC-S is found in close proximity to the mitochondria. To study wild type and mutant CIC function and motivated by the paucity of 1p19q co-deleted ODG lines, we created HEK293 and HOG stable cell lines ectopically co-expressing CIC and IDH1. Non-mutant lines displayed increased clonogenicity, but cells co-expressing the mutant IDH1-R132H with either CIC-S-R201W or -R1515H showed reduced clonogenicity in an additive manner, demonstrating cooperative effects in our assays. Expression of mutant CIC-R1515H increased cellular 2-Hydroxyglutarate (2HG) levels compared to wild type CIC in IDH1-R132H background. Levels of phosphorylated ATP-citrate Lyase (ACLY) were lower in cell lines expressing mutant CIC-S proteins compared to cells expressing wild type CIC-S, supporting a cytosolic citrate metabolism-related mechanism of reduced clonogenicity in our in vitro model systems. ACLY or phospho-ACLY were similarly reduced in CIC-mutant 1p19q co-deleted oligodendroglioma patient samples
Anticipating by Pigeons Depends on Local Statistical Information in a Serial Response Time Task.
Generalization Mediates Sensitivity to Complex Odor Features in the Honeybee
Animals use odors as signals for mate, kin, and food recognition, a strategy which appears ubiquitous and successful despite the high intrinsic variability of naturally-occurring odor quantities. Stimulus generalization, or the ability to decide that two objects, though readily distinguishable, are similar enough to afford the same consequence [1], could help animals adjust to variation in odor signals without losing sensitivity to key inter-stimulus differences. The present study was designed to investigate whether an animal's ability to generalize learned associations to novel odors can be influenced by the nature of the associated outcome. We use a classical conditioning paradigm for studying olfactory learning in honeybees [2] to show that honeybees conditioned on either a fixed- or variable-proportion binary odor mixture generalize learned responses to novel proportions of the same mixture even when inter-odor differences are substantial. We also show that the resulting olfactory generalization gradients depend critically on both the nature of the stimulus-reward paradigm and the intrinsic variability of the conditioned stimulus. The reward dependency we observe must be cognitive rather than perceptual in nature, and we argue that outcome-dependent generalization is necessary for maintaining sensitivity to inter-odor differences in complex olfactory scenes
Comparison of the clinical and economic outcomes between open and minimally invasive appendectomy and colectomy: evidence from a large commercial payer database
Background: Appendectomy and colectomy are commonly performed surgical procedures. Despite evidence demonstrating advantages with the minimally invasive surgical (MIS) approach, open procedures occur with greater prevalence. Therefore, there is still controversy as to whether the MIS approach is safer or more cost effective. Methods: A retrospective analysis was performed using a large commercial payer database. The data included information on 7,532 appendectomies and 2,745 colectomies. Data on the distribution of patient demographic and comorbidity characteristics associated with the MIS and open approaches were reviewed. The corresponding complication rates and expenditures were analyzed. Summary statistics were compared using chi-square tests, and generalized linear models were constructed to estimate expenditures while controlling for patient characteristics. Results: The patients undergoing MIS and open colectomy showed no significant variations in age distribution or marginal age differences for appendectomy. Significantly more patients experienced an infection postoperatively, and procedure-specific complications were more common in the open group for both procedures (PÂ <Â 0.05). The postsurgical hospital stay was longer for the patients treated using the open techniques, differing an average of half a day for appendectomies and significantly more (4Â days) for colectomy (PÂ <Â 0.05). Readmission rates differed little between the two approaches. Procedures performed through an MIS approach were associated with lower expenditures than for the open technique, with differences ranging from 15,200 for colectomy patients (PÂ < 0.05). Conclusions: Minimally invasive appendectomy and colectomy were associated with lower infection rates, fewer complications, shorter hospital stays, and lower expenditures than open surgery
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