84 research outputs found
Accessing default risk of a public company with structural models : AcF 706 : CFA-Stream dissertation
There are various ways to evaluate the credit risk of a public company using both
market data as well as accounting data. This paper focuses on applying two structural
models, Merton (1974) and Leland (1994), to access the default risk of a public
company, Thomas Cook Group plc. With estimated default probabilities higher than
90% during 2011 to 2012, it is shown that both models can predict bankruptcy, which
is in the form of debt restructuring and capital refinancing in early 2013. The Leland
model also suggests that there exists an optimal capital structure that could minimize
the credit spread
NETWORK DEVICE SYSTEM LOGGING SUMMARIZATION BASED ON LOW-RANK ADAPTATION AND CONTRASTIVE LEARNING
Techniques are presented herein that support the automatic generation of refined and summarized text from a system logging (syslog) message sequence. Aspects of the presented techniques employ an abstractive syslog summarization large language model (LLM) that is trained with contrastive learning and then fine-tuned using a Low-Rank Adaptation (LoRA) methodology. Under further aspects of the presented techniques, auxiliary text (such as network incident reports and application incident reports) is added to the prompt of the input of the LLM model to help the model generate a richer syslog summarization
Activating mu-opioid receptors in the spinal cord mediates the cardioprotective effect of remote preconditioning of trauma
Background: Remote precoditioning of trauma (RPCT) confers cardioprotective effects against myocardial ischemia/reperfusion injury, which are mediated by spinal opioid receptors. The aim of this study was to identify the roles of opioid receptor subtypes in the cardioprotective effect of RPCT and possible mechanisms.
Methods: In this study, 192 Sprague-Dawley rats were allocated to 12 groups. Except for the sham group, rats in all groups were subjected to myocardial ischemia reperfusion. Rats in the ischemia precondition (IPC) group were treated with IPC. In the RPCT groups, an abdominal incision was made 15 min before inducing ischemia. The selective delta-, kappa-, and mu-opioid receptor antagonists were administered to groups of animals receiving RPCT, respectively. Data were collected for myocardial infarct size, intercellular adhesion molecule 1 (ICAM-1), plasma cardiac troponin I (cTnI) concentrations, activation of protein kinase C epsilon (PKCe) in myocardial cell membranes, and adenosine release in the spinal cord.
Results: Compared with the control groups, infarct size, plasma concentrations of cTnI, and myocardial ICAM-1 expression were significantly lower, while adenosine release and PKCe activation were enhanced in the IPC and RPCT groups. Compared with the RPCT group, infarct size, plasma cTnI concentration, and myocardial ICAM-1 expression were greater and adenosine release and PKCe activation were reduced in the mu-opioid receptor antagonist plus RPCT group.
Conclusions: The spinal mu-opioid receptor mediated the cardiac protective effect of RPCT. The mechanism may be enhanced by adenosine release in the spinal cord and PKCe activation in the myoÂcardium, thereby inhibiting inflammation induced by ischemia/reperfusion injury
Recommended from our members
Survivin overexpression is potentially associated with pituitary adenoma invasiveness
Background and objective Survivin is an inhibitor of apoptosis. Its role in guiding the treatment of neoplasms, making diagnosis and predicting prognosis has been reported. However, there is little information on the implications and uses of survivin in predicting pituitary adenoma (PA) invasiveness. Existing information is unclear and controversial. We thus conducted this meta-analysis to explore whether the surviving expression levels in invasive PAs (IPA) and regular PAs are different or not. We considered both non-secreting and secreting tumors together. Methods: A global search strategy was systematically applied among five databases including Cochrane Library, Embase, PubMed, Web of Science, and Chinese National Knowledge Infrastructure (CNKI) up to June 18th, 2017. With a specially designed form including PAsâ invasive features, etc., data was collected. The included studies should present the data representing the surviving levels in IPA groups and regular PA groups, respectively. Differences were expressed as standard mean differences (SMDs) or odds ratios (ORs) with 95% confidence interval (CI). To estimate the heterogeneities, I2 test, Cochran's Q-test and Galbr figure were all conducted. A sensitivity-analysis and potential-publication bias were also performed. Results: In the present meta-analysis, 9 studies containing 489 patients were included. Seven studies with dichotomous-data showed that survivin over-expression in PA tissue was closely associated with a high invasive tendency (OR 6.226, 95% CI 3.970, 9.765; P<0.001), but 2 continuous-data studies revealed that there was no significant association (SMD â5.043, 95% CI-10.965, 0.878; p=0.095). A sensitivity-analysis suggested a statistically stable result. We did not find publication bias. Conclusion: We suggest that survivin overexpression is potentially associated with PA invasiveness. More research based on medical big data is needed to confirm this finding
Does Abnormal Preoperative Coagulation Status Lead to More Perioperative Blood Loss in Spinal Deformity Correction Surgery?
This study aims to analyze the potential association between the preoperative coagulation status and perioperative blood loss in spinal deformity correction surgery. The preoperative coagulation status and estimated blood loss (EBL) during operation, postoperative wound drainage, and allogeneic transfusion during and after operation were recorded and analyzed. Among the 164 patients, 26 had a longer prothrombin time (PT), 13 had a lower fibrinogen level, 55 had a longer activated partial thromboplastin time (APTT), and 2 had a longer thrombin time (TT), and the platelet count (PLT) was all normal or higher than the normal level. The mean EBL per surgical level was 77.8â
ml (range, 22â267â
ml), and the mean drainage per surgical level was 52.7â
ml (range, 7â168â
ml). Fifty-five patients and 12 patients underwent allogeneic transfusion during and after the operation, respectively. The differences in EBL per surgical level, mean drainage per surgical level, the occurrences of allogeneic transfusion during and after operation between the patients with a longer PT, lower fibrinogen level, longer APTT or longer TT, and the normal controls were not significant (all Pâsâ>â0.05). The Spearman correlation analysis showed that there was no correlation between PT, fibrinogen, APTT, TT or PLT with EBL per surgical level, mean drainage per surgical level, or allogeneic transfusion during and after the operation (all Pâsâ>â0.05). The abnormal preoperative coagulation status but not hemophilia does not lead to more perioperative blood loss or a higher rate of perioperative allogeneic transfusion in spinal deformity correction surgery
The complex hexaploid oilâCamellia genome traces back its phylogenomic history and multiâomics analysis of Camellia oil biosynthesis
Summary: OilâCamellia (Camellia oleifera), belonging to the Theaceae family Camellia, is an important woody edible oil tree species. The Camellia oil in its mature seed kernels, mainly consists of more than 90% unsaturated fatty acids, tea polyphenols, flavonoids, squalene and other active substances, which is one of the best quality edible vegetable oils in the world. However, genetic research and molecular breeding on oilâCamellia are challenging due to its complex genetic background. Here, we successfully report a chromosomeâscale genome assembly for a hexaploid oilâCamellia cultivar Changlin40. This assembly contains 8.80 Gb genomic sequences with scaffold N50 of 180.0 Mb and 45 pseudochromosomes comprising 15 homologous groups with three members each, which contain 135 868 genes with an average length of 3936 bp. Referring to the diploid genome, intragenomic and intergenomic comparisons of synteny indicate homologous chromosomal similarity and changes. Moreover, comparative and evolutionary analyses reveal three rounds of wholeâgenome duplication (WGD) events, as well as the possible diversification of hexaploid Changlin40 with diploid occurred approximately 9.06 million years ago (MYA). Furthermore, through the combination of genomics, transcriptomics and metabolomics approaches, a complex regulatory network was constructed and allows to identify potential key structural genes (SAD, FAD2 and FAD3) and transcription factors (AP2 and C2H2) that regulate the metabolism of Camellia oil, especially for unsaturated fatty acids biosynthesis. Overall, the genomic resource generated from this study has great potential to accelerate the research for the molecular biology and genetic improvement of hexaploid oilâCamellia, as well as to understand polyploid genome evolution
Sigma metrics for assessing the analytical quality of clinical chemistry assays: a comparison of two approaches
Introduction: Two approaches were compared for the calculation of coefficient of variation (CV) and bias, and their effect on sigma calculation,
when different allowable total error (TEa) values were used to determine the optimal method for Six Sigma quality management in the clinical laboratory.
Materials and methods: Sigma metrics for routine clinical chemistry tests using three systems (Beckman AU5800, Roche C8000, Siemens Dimension)
were determined in June 2017 in the laboratory of Peking Union Medical College Hospital. Imprecision (CV%) and bias (bias%) were calculated
for ten routine clinical chemistry tests using a proficiency testing (PT)- or an internal quality control (IQC)-based approach. Allowable total error from
the Clinical Laboratory Improvement Amendments of 1988 and the Chinese Ministry of Health Clinical Laboratory Center Industry Standard (WS/
T403-2012) were used with the formula: Sigma = (TEa â bias) / CV to calculate the Sigma metrics (ÏCLIA, ÏWS/T) for each assay for comparative analysis.
Results: For the PT-based approach, eight assays on the Beckman AU5800 system, seven assays on the Roche C8000 system and six assays on the
Siemens Dimension system showed ÏCLIA > 3. For the IQC-based approach, ten, nine and seven assays, respectively, showed ÏCLIA > 3. Some differences
in Ï were therefore observed between the two calculation methods and the different TEa values.
Conclusions: Both methods of calculating Ï can be used for Six Sigma quality management. In practice, laboratories should evaluate Sigma multiple
times when optimizing a quality control schedule
Structural and mechanistic insights into the biosynthesis of CDP-archaeol in membranes
The divergence of archaea, bacteria and eukaryotes was a fundamental step in evolution. One marker of this event is a major difference in membrane lipid chemistry between these kingdoms. Whereas the membranes of bacteria and eukaryotes primarily consist of straight fatty acids ester-bonded to glycerol-3-phosphate, archaeal phospholipids consist of isoprenoid chains ether-bonded to glycerol-1-phosphate. Notably, the mechanisms underlying the biosynthesis of these lipids remain elusive. Here, we report the structure of the CDP-archaeol synthase (CarS) of Aeropyrum pernix (ApCarS) in the CTP- and Mg(2+)-bound state at a resolution of 2.4 Ă
. The enzyme comprises a transmembrane domain with five helices and cytoplasmic loops that together form a large charged cavity providing a binding site for CTP. Identification of the binding location of CTP and Mg(2+) enabled modeling of the specific lipophilic substrate-binding site, which was supported by site-directed mutagenesis, substrate-binding affinity analyses, and enzyme assays. We propose that archaeol binds within two hydrophobic membrane-embedded grooves formed by the flexible transmembrane helix 5 (TM5), together with TM1 and TM4. Collectively, structural comparisons and analyses, combined with functional studies, not only elucidated the mechanism governing the biosynthesis of phospholipids with ether-bonded isoprenoid chains by CTP transferase, but also provided insights into the evolution of this enzyme superfamily from archaea to bacteria and eukaryotes.Cell Research advance online publication 29 September 2017; doi:10.1038/cr.2017.122
Effects of Total Flavone from Rhododendron simsii Planch. Flower on Postischemic Cardiac Dysfunction and Cardiac Remodeling in Rats
This study investigated the effect of total flavone from Rhododendron simsii Planch. flower (TFR) on postischemic cardiac dysfunction and ventricular remodeling and was to test the hypothesis that TFR has an antiventricular remodeling effect through inhibition of urotensin-II receptor- (UTR-) mediated activation of RhoA-ROCK pathways. Twenty-four hours after ligation of the left anterior descending coronary artery, male Sprague-Dawley rats were randomized to receive 4-week treatment with saline (model group) or TFR. Compared to the model group, TFR treatment restored cardiac function, attenuated cardiomyocyte hypertrophy, and reduced interstitial fibrosis. Expression levels of several fibrosis-related factors, including alpha-smooth muscle actin, transforming growth factor-beta 1, matrix metalloproteinase-2, and collagen type I, were increased after MI. TFR treatment attenuated the upregulation of these factors, downregulated UTR expression, and markedly diminished the expression of RhoA and ROCK1/2. These results suggested that TFR could improve cardiac function and ameliorate ventricular remodeling through blocking UTR-mediated activation of RhoA-ROCK pathways in myocardial infarction rats
- âŠ