Class A and Class C numerical predictions of the deformation of an embankment on soft ground

2018 ◽  
Vol 93 ◽  
pp. 191-203 ◽  
Author(s):  
Stephen Buttling ◽  
Robin Cao ◽  
Winston Lau ◽  
Dheavini Naicker
Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 42
Author(s):  
Jemal Jibril Muhammed ◽  
Priyantha W. Jayawickrama ◽  
Stephen Ekwaro-Osire

This paper presents the quantification of uncertainties in the prediction of settlements of embankments built on prefabricated vertical drains (PVDs) improved soft soil deposits based on data collected from two well-documented projects, located in Karakore, Ethiopia, and Ballina, Australia. For this purpose, settlement prediction biases and settlement distributions were statistically computed based on analyses conducted on two Class A and Class C numerical predictions made using PLAXIS 2D finite element modelling. From the results of prediction bias, Class C predictions agreed well with the field measured settlements at both sites. In Class C predictions, the computed settlements were biased to the measured values. For Class A predictions, the calculated settlement values were in the range of mean and mean minus 3SD (standard deviations) for Karakore clay, and they were within mean and mean minus 2SD limit for the Ballina soil. The contributing factors to the settlement uncertainties of the Karakore site may include variability within the soil profile of the alluvial deposit, particularly the presence of interbedded granular layer within the soft layers, and the high embankment fills, and the limited number of samples available for laboratory testing. At the Ballina test embankment site, the uncertainties may have been associated with the presence of transitional layers at the bottom of estuarine clay and sensitivity of soft soil to sample disturbances and limitations in representing all the site conditions.


2020 ◽  
Vol 29 (1) ◽  
pp. 81-88
Author(s):  
Virendra Kumar Verma ◽  
Nishant Mittal ◽  
Ramesh Chandra

AbstractWe present an investigation of halo coronal mass ejections (HCMEs) kinematics and other facts about the HCMEs. The study of HCMEs is very important because HCMEs are regarded as the main causes of heliospheric and geomagnetic disturbances. In this study, we have investigated 313 HCMEs observed during 1996-2012 by LASCO, coronal holes, and solar flares. We find that HCMEs are of two types: accelerated HCMEs and decelerated HCMEs. The mean space speed of HCMEs is 1283 km/s while the mean speed of decelerated HCMEs and accelerated HCMEs is 1349 km/s and 1174 km/s, respectively. The investigation shows that 1 (0.3%) HCME was associated with class A SXR, 14 (4.7%) HCMEs were associated with class B SXR-flares, 87 (29.4%) HCMEs were associated with class C SXR-flares, 125 (42.2%) HCMEs were associated with class M SXR-flares and 69 (23.3%) HCMEs were associated with class X SXR-flares. The speed of HCMEs increases with the importance of solar SXR-flares. The various results obtained in the present analysis are discussed in the light of the existing scenario of heliospheric physics.


2011 ◽  
Vol 114 (3) ◽  
pp. 842-849 ◽  
Author(s):  
Robert F. Spetzler ◽  
Francisco A. Ponce

Object The authors propose a 3-tier classification for cerebral arteriovenous malformations (AVMs). The classification is based on the original 5-tier Spetzler-Martin grading system, and reflects the treatment paradigm for these lesions. The implications of this modification in the literature are explored. Methods Class A combines Grades I and II AVMs, Class B are Grade III AVMs, and Class C combines Grades IV and V AVMs. Recommended management is surgery for Class A AVMs, multimodality treatment for Class B, and observation for Class C, with exceptions to the latter including recurrent hemorrhages and progressive neurological deficits. To evaluate whether combining grades is warranted from the perspective of surgical outcomes, the 3-tier system was applied to 1476 patients from 7 surgical series in which results were stratified according to Spetzler-Martin grades. Results Pairwise comparisons of individual Spetzler-Martin grades in the series analyzed showed the fewest significant differences (p < 0.05) in outcomes between Grades I and II AVMs and between Grades IV and V AVMs. In the pooled data analysis, significant differences in outcomes were found between all grades except IV and V (p = 0.38), and the lowest relative risks were found between Grades I and II (1.066) and between Grades IV and V (1.095). Using the pooled data, the predictive accuracies for surgical outcomes of the 5-tier and 3-tier systems were equivalent (receiver operating characteristic curve area 0.711 and 0.713, respectively). Conclusions Combining Grades I and II AVMs and combining Grades IV and V AVMs is justified in part because the differences in surgical results between these respective pairs are small. The proposed 3-tier classification of AVMs offers simplification of the Spetzler-Martin system, provides a guide to treatment, and is predictive of outcome. The revised classification not only simplifies treatment recommendations; by placing patients into 3 as opposed to 5 groups, statistical power is markedly increased for series comparisons.


2017 ◽  
Vol 7 (2) ◽  
pp. 182-199 ◽  
Author(s):  
Rebecca D. Folkerth ◽  
Jacqueline Nunez ◽  
Zhanna Georgievskaya ◽  
Declan McGuone

In infants and toddlers (less than four years of age), determination of cause and manner of death often requires a complete autopsy. Few evidence-based guidelines exist regarding optimum nervous system sectioning in this population. Over a six-month interval and using a comprehensive section protocol, we categorized cases having neuropathological findings that were critical (Class A), contributory (Class B), or noncontributory (Class C) to the final cause and manner of death. We further evaluated which sections helped make this determination. Among 53 cases (44 infants, 9 toddlers; 26 girls, 27 boys), Class A neuropathology was noted in nine (16.9%). Seven infants had meningoencephalitis (2/7, 28.6%), craniospinal trauma (3/7, 42.8%), brainstem necrosis suggesting Leigh Disease (1/7, 14.3%), and hydrocephalus in Dandy-Walker malformation (1/7, 14.3%); two toddlers had inflicted craniospinal trauma (2/2, 100%). Class B factors were identified in 11/53 (20.8%), including recent hypoxic-ischemic lesions (2/11, 18.2%), meningitis or dural venous sinus thrombosis in systemic sepsis (2/11, 18.2%), multicystic encephalopathy following peripartum asphyxia (2/11, 18.2%), and microcephaly and delayed myelination (Cri-du-Chat Syndrome) (1/11, 9.09%). Class B also included three toddlers (3/11, 27.2%) with features of hippocampal dysgenesis, two in the setting of febrile seizures. Class C comprised normal brains (3/53, 5.7%), and those with findings of uncertain significance, such as white matter and brainstem gliosis (30/53, 56.6%). The sections most valuable for detection of relevant pathology, and thus recommended for routine sampling, were: 1) bilateral hippocampus; 2) cerebral cortex and leptomeninges; and 3) pons or medulla.


2009 ◽  
Vol 75 (13) ◽  
pp. 4277-4288 ◽  
Author(s):  
Ihab Habib ◽  
Rogier Louwen ◽  
Mieke Uyttendaele ◽  
Kurt Houf ◽  
Olivier Vandenberg ◽  
...  

ABSTRACT Significant interest in studying the lipooligosaccharide (LOS) of Campylobacter jejuni has stemmed from its potential role in postinfection paralytic disorders. In this study we present the results of PCR screening of five LOS locus classes (A, B, C, D, and E) for a collection of 116 C. jejuni isolates from chicken meat (n = 76) and sporadic human cases of diarrhea (n = 40). We correlated LOS classes with clonal complexes (CC) assigned by multilocus sequence typing (MLST). Finally, we evaluated the invasion potential of a panel of 52 of these C. jejuni isolates for Caco-2 cells. PCR screening showed that 87.1% (101/116) of isolates could be assigned to LOS class A, B, C, D, or E. Concordance between LOS classes and certain MLST CC was revealed. The majority (85.7% [24/28]) of C. jejuni isolates grouped in CC-21 were shown to express LOS locus class C. The invasion potential of C. jejuni isolates possessing sialylated LOS (n = 29; classes A, B, and C) for Caco-2 cells was significantly higher (P < 0.0001) than that of C. jejuni isolates with nonsialylated LOS (n = 23; classes D and E). There was no significant difference in invasiveness between chicken meat and human isolates. However, C. jejuni isolates assigned to CC-206 (correlated with LOS class B) or CC-21 (correlated with LOS class C) showed statistically significantly higher levels of invasion than isolates from other CC. Correlation between LOS classes and CC was further confirmed by pulsed-field gel electrophoresis. The present study reveals a correlation between genotypic diversity and LOS locus classes of C. jejuni. We showed that simple PCR screening for C. jejuni LOS classes could reliably predict certain MLST CC and add to the interpretation of molecular-typing results. Our study corroborates that sialylation of LOS is advantageous for C. jejuni fitness and virulence in different hosts. The modulation of cell surface carbohydrate structure could enhance the ability of C. jejuni to adapt to or survive in a host.


2008 ◽  
Vol 53 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Susanne Paukner ◽  
Lars Hesse ◽  
Andrej Preželj ◽  
Tomaž Šolmajer ◽  
Uroš Urleb

ABSTRACT LK-157 is a novel tricyclic carbapenem with potent activity against class A and class C β-lactamases. When tested against the purified TEM-1 and SHV-1 enzymes, LK-157 exhibited 50% inhibitory concentrations (IC50s) in the ranges of the clavulanic acid and tazobactam IC50s (55 nM and 151 nM, respectively). Moreover, LK-157 significantly inhibited AmpC β-lactamase (IC50, 62 nM), as LK-157 was >2,000-fold more potent than clavulanic acid and approximately 28-fold more active than tazobactam. The in vitro activities of LK-157 in combination with amoxicillin, piperacillin, ceftazidime, cefotaxime, ceftriaxone, cefepime, cefpirome, and aztreonam against an array of Ambler class A (TEM-, SHV-, CTX-M-, KPC-, PER-, BRO-, and PC-type)- and class C-producing bacterial strains derived from clinical settings were evaluated in synergism experiments and compared with those of clavulanic acid, tazobactam, and sulbactam. In vitro MICs against ESBL-producing strains (except CTX-M-containing strains) were reduced 2- to >256-fold, and those against AmpC-producing strains were reduced even up to >32-fold. The lowest MICs (≤0.025 to 1.6 μg/ml) were observed for the combination of cefepime and cefpirome with a constant LK-157 concentration of 4 μg/ml, thus raising an interest for further development. LK-157 proved to be a potent β-lactamase inhibitor, combining activity against class A and class C β-lactamases, which is an absolute necessity for use in the clinical setting due to the worldwide increasing prevalence of bacterial strains resistant to β-lactam antibiotics.


2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Andrew Mack ◽  
Vijay Kumar ◽  
Magdalena Taracila ◽  
Malcolm Page ◽  
Robert Bonomo ◽  
...  
Keyword(s):  
Class A ◽  
Class C ◽  

2021 ◽  
Vol 15 (10) ◽  
pp. 2779-2782
Author(s):  
Saira Khalid ◽  
Nasir Shah ◽  
Yasir Abbas Zaidi ◽  
Muhammad Saleem Hasan ◽  
Saqib Jahangir ◽  
...  

Study Objectives: To determine the frequency of cirrhotic cardiomyopathy in patients with liver cirrhosis and to compare it across varying grades of cirrhosis on Child Turcotte Pugh classification. Study Design and Settings: It was a descriptive cross-sectional study carried at Department of Medicine, Lahore General Hospital Lahore over 1 year from Jan 2018 to Dec 2018. Patients and Methods: The present research involved 100 male and female patients aged between 16-70 years having liver cirrhosis diagnosed at least 6 months ago. These patients underwent echocardiographic screening of cardiomyopathy which was diagnosed by the presence of diastolic dysfunction (i.e. increased E/A ratio>1). An informed written consent was obtained from every patient. Results of the Study: There was a male predominance (M:F, 1.6:1) among cirrhotic patients with a mean age of 51.9±9.8 years. The mean BMI was 26.5±3.7 Kg/m2 while the mean duration of cirrhosis was 22.0±10.9 months. Majority (49.0%) of the patients belonged to CTP Class C followed by Class-B (39.0%) and Class-A (12.0%). Cirrhotic cardiomyopathy was observed in 41.0% patients with cirrhosis. There was statistically insignificant difference in the observed frequency of cirrhotic cardiomyopathy among various subgroups of cirrhotic patients depending upon patient’s age (p-value=0.928), gender (p-value=0.997), BMI (p-value=0.983) and duration of disease (p-value=0.782). However, it increased considerably with worsening of disease on CTP Classification; Class-A vs. Class-B vs. Class-C (8.3% vs. 35.9% vs. 53.1%; p-value=0.013). Conclusion: Cirrhotic cardiomyopathy was observed in a substantial proportion of cirrhotic patients and was more frequent in patients with more severe disease which warrants routine echocardiographic screening of cirrhotic patients so that timely recognition and anticipated treatment of this complication may improve the case outcome in future medical practice. Keywords: Cirrhosis, Cardiomyopathy, Child Turcotte Pugh Class


1987 ◽  
Vol 57 (4) ◽  
pp. 962-976 ◽  
Author(s):  
D. J. Surmeier ◽  
A. L. Towe

The intrinsic processes contributing to the three discharge patterns of proprioceptive cuneate neurons described by Surmeier and Towe were studied experimentally and with computer simulation. Examination of the alterations in excitability produced by antidromic activation suggested that a prolonged inhibition was a concomitant of discharge in proprioceptive cuneate neurons. Computer simulation was performed to test the possible roles of inhibitory hyperpolarizing processes in governing the observed discharge patterns. These simulations used two constant threshold models. The simplest model linearly integrated synaptic potentials until the spike threshold was reached. After the discharge, synaptic potentials that preceded the spike were ignored (i.e., the model was "reset"). The second model was similar to the first except that following a spike two hyperpolarizing processes were activated and preceding events continued to play a role in membrane potential. Simulation of class A spike trains that possessed positive correlations between nearby intervals was successful only with a resetting model. This suggested that class A neurons have fast, no-memory postspike conductance changes, which effectively shunt synaptic charge. Simulation of class B spike trains was possible with the nonresetting model. At least two periodic inputs, which evoked brief, relatively large EPSPs, were required. In addition, a prominent, fast, spike-dependent hyperpolarization and a small-amplitude, slow hyperpolarization were required. Simulation of class C spike trains was also possible with the nonresetting model. Several periodic inputs were required; one input had to evoke a slow suprathreshold EPSP. In contrast to class B simulations, class C spike train simulation required that a large-amplitude, slow hyperpolarization, as well as a brief hyperpolarization, following spike initiation. The results of class B and C simulations suggested that these two groups differed primarily in the amplitude of a slow, hyperpolarizing, postspike conductance. Some role may also be played by the time course of the driving EPSPs.


2016 ◽  
Vol 60 (5) ◽  
pp. 3183-3186 ◽  
Author(s):  
Sushmita D. Lahiri ◽  
Richard A. Alm

ABSTRACTCeftazidime-avibactam has activity againstPseudomonas aeruginosaandEnterobacteriaceaeexpressing numerous class A and class C β-lactamases, although the ability to inhibit many minor enzyme variants has not been established. Novel VEB class A β-lactamases were identified during characterization of surveillance isolates. The cloned novel VEB β-lactamases possessed an extended-spectrum β-lactamase phenotype and were inhibited by avibactam in a concentration-dependent manner. The residues that comprised the avibactam binding pocket were either identical or functionally conserved. These data demonstrate that avibactam can inhibit VEB β-lactamases.


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