scholarly journals Some kinematics of halo coronal mass ejections

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.

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


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.


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.


1931 ◽  
Vol 5 (2) ◽  
pp. 208-218 ◽  
Author(s):  
J. B. Harrington

The relationship between the degree of plumpness of F2 seeds and the type of the resulting F2 plants was studied in the cross Vernal (T. dicoccum) × Marquis (T. vulgare). A random sample of F2 seeds was divided into three classes based upon kernel plumpness, viz. plump (Class A), slightly shrunken (Class B), and shrunken (Class C). In these there were by number 55.5, 41.0 and 3.5% of seeds respectively. Emergence of F2 plants in the field was 64, 58 and 36% for Classes A, B and C. The F2 plants were studied for 13 morphological characters. Comparing the populations for all characters combined, Class A was more dicoccum-like than Class B, and Class B much more dicoccum-like than Class C. The proportion of vulgare-like character was 16, 20 and 32% for Classes A, B and C, respectively. Considering the character of the individual plants, the ratios of dicoccum-like to vulgare-like were 12.1:1, 5.3:1, and 2.2:1 for classes A, B and C, respectively. Furthermore, the vulgare-like plants of classes A and B were less vulgare-like than those of Class C. There were present, however, in Classes A and B some plants that were fully as vulgare-like as any in Class C. These results indicate that, in an interspecific wheat cross, the breeder should give special attention to the shrunken F2 seeds if he has very limited nursery space and a large amount of seed; whereas if he has plenty of space for a large population, special care of shrunken F2 seeds does not seem warranted.


1989 ◽  
Vol 104 (2) ◽  
pp. 239-242
Author(s):  
V.K. Verma ◽  
M.C. Pande

AbstractThe coronal mass ejection (CME) data and the data for coronal holes for the period 1979-1982 are compared locationwise. Out of 79 CMEs whose locations and spans are known, 48 (61%) CMEs are associated with coronal holes. We make a tentative suggestion that probably the mass ejected during solar flares and active prominences may move along the open magnetic field of the coronal holes and appear as CMEs.


2014 ◽  
Vol 21 (06) ◽  
pp. 1222-1226
Author(s):  
Muhammad Amjad Kalhoro ◽  
Irfan Murtaza Shahwani ◽  
Mashooque Ali Dasti ◽  
Syed Zulfiquar Ali Shah ◽  
Faisal Shahab ◽  
...  

Objective: To determine the frequency of hepatocellular carcinoma in different Child-Pugh classes based on Alfa fetoprotein level. Study design: Case series study. Period: Six months Setting: Medical Unit-I of Liaquat University Hospital, Hyderabad Sindh Pakistan. Patients & Methods: A total of 100 patients admitted (inpatients) in Medical Unit I with the diagnosis of cirrhosis were enrolled in the study. Patients with cirrhosis of liver (more than six month duration) of either gender were included. If patients had metastatic lesion of the liver, liver abscess, or acute liver failure then they were excluded. Child-Pugh score was calculated which included ascites, encephalopathy, prothrombin time, albumin and serum bilirubin. The levels of α-fetoprotein were measured and HCC was diagnosed. The primary outcome variable was presence of HCC in cirrhotic patients. Results: The proportion of males (53%) was higher as compared to females (47%). The mean age of the study patients was 40.47 years with a standard deviation of 11.5. At the beginning patients were categorized according to Child Pugh Classes (A= up to 6, B=7-9 and C=10-11), age groups (15-30 years, 31-50 years and 51-70 years respectively). The mean Child Pugh score was 6.83 with ± 1.8 S.D. The majority of the cases of HCC (75.61%) occurred in the Child Class A, whereas 21.95% occurred in Child Class B and finally only one case of HCC (2.44%) was present in Child Class C. Conclusions: This study comprehensively demonstrated that hepatocellular carcinoma (HCC) is far more common in compensated cirrhosis (Child Pugh Class A) vs. decompensated cirrhosis (Child Pugh Class B and C).


2021 ◽  
Vol 22 (2) ◽  
pp. 100-106
Author(s):  
Tarana Yasmin ◽  
Sohely Sultana ◽  
Mahmuda Nusrat Ima ◽  
Md Quamrul Islam ◽  
Shyamal Kumar Roy ◽  
...  

Background: Cirrhosis is a common problem and is a leading cause of chronic liver disease. Early diagnosis with assessment of severity of diseases may help prevent the associated complications and patients’ sufferings. Now a days Hepatic venous Doppler can be a tool for diagnosis of cirrhosis and to assess correlation between waveform changes and severity of diseases. Objective: The purposes of this study was to determine the significance of hepatic vein waveform changes on doppler ultrasound in cirrhotic patients and to correlate with liver dysfunction. Materials and methods: This study was carried out in the department of Radiology and Imaging of Enam Medical College and Hospital during January 2017 to May 2018. Doppler waveforms were obtained from right hepatic vein in all the cases and classified as triphasic, biphasic and monophasic. Waveform comparisons were made among patients with differing grades of cirrhosis. Child- Pugh class was used to assess severity of cirrhosis. Doppler sonography was done in 80 patients suspecting of having liver cirrhosis. Data on clinical findings, B mode sonographic findings and hepatic vein doppler ultrasound findings were collected and documented in structured forms. Analysis was done using SPSS - 20. Results: Total of 80 patients who met the inclusion criteria are included in the study with mean age of 45.37±7.64 (range 25-75) years. Among these 57 (71%) were males while 23(29%) were females. On the basis of hepatic function 25 (31%) patients presented in Child-Pugh Class A, 31(39%) with Class B and 24(30%) patients had Class C. Hepatic venous waveform was triphasic in 22 (27.5%), biphasic in 28(35%), and monophasic in 30 (37.5%) cases. Our study revealed 88% (21) of Child- Pugh Class C, 23% (7) of Class B and 8% (2) of class A patients had monophasic HV waveform. The hepatic venous waveform progressively changed from triphasic to biphasic to monophasic with advancing grade of cirrhosis. The relationship of these waveforms change had significant relation with hepatic dysfunction (p < 0.022). Conclusion: Hepatic vein wave form changes reflects the change in hepatic circulation associated with progression of liver cirrhosis. It can be used as a new parameter in the assessment of severity of liver cirrhosis. Thus, alteration in hepatic venous blood flow pattern on doppler ultrasound can be a useful noninvasive tool for evaluating diseases severity in patients with cirrhosis. J MEDICINE 2021; 22: 100-106


2020 ◽  
Vol 9 (4) ◽  
pp. 499-511
Author(s):  
M. Ahied ◽  
L. K. Muharrami ◽  
A. Fikriyah ◽  
I. Rosidi

Scientific literacy is a capability to identify problems, analyze questions, and create solutions by applying scientific knowledge and integrating science with technology and society. This literacy needs to be improved so that students can develop their skills in identifying science phenomenon and addressing various solutions. Although the learning was conducted in distance since the current situation is still amid the COVID-19 pandemic, the literacy can be taught during the learning process. This study aims to improve students’ scientific literacy through distance learning with augmented reality-based multimedia amid the COVID-19 pandemic. The research included in a descriptive quantitative study with pre-test and post-test design. The distance learning was conducted in the lecture of anatomy and physiology of organism during even semester in May 2020, with 111 students from three classes in the 2018 academic year. The science content provided in online learning was supported by augmented-reality based multimedia on the topic of the human respiratory system. This multimedia was evaluated, also stated as valid and appropriate to be implemented in the learning process. Scientific literacy was measured using the online test form. The findings indicated that the students’ scientific literacy improved moderately both in class A and B, but low in class C. The improvement of scientific literacy in class A reached N-gain average score of 0.31, class B reached 0.38, and class C reached 0.22. Students also gave a positive response, showed by the percentages of students’ response at 89.1% in class A, 87.0% in class B, and 84.8% in class C, which was in the very strong category. Therefore, it can be concluded that students’ scientific literacy improved well through distance learning with augmented reality-based multimedia amid the COVID-19 pandemic.


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