2,409 research outputs found
Non-Linear Langevin and Fractional Fokker-Planck Equations for Anomalous Diffusion by Levy Stable Processes
The~numerical solutions to a non-linear Fractional Fokker--Planck (FFP)
equation are studied estimating the generalized diffusion coefficients. The~aim
is to model anomalous diffusion using an FFP description with fractional
velocity derivatives and Langevin dynamics where L\'{e}vy fluctuations are
introduced to model the effect of non-local transport due to fractional
diffusion in velocity space. Distribution functions are found using numerical
means for varying degrees of fractionality of the stable L\'{e}vy distribution
as solutions to the FFP equation. The~statistical properties of the
distribution functions are assessed by a generalized normalized expectation
measure and entropy and modified transport coefficient. The~transport
coefficient significantly increases with decreasing fractality which is
corroborated by analysis of experimental data.Comment: 20 pages 7 figure
Nutritional & Colorectal Health
Kentucky has the highest incidence and mortality rate of all site cancers, and Kentuckians residing in the Appalachian region often have worse outcomes, where cancer is a leading cause of death. Focusing on colorectal cancer (CRC) specifically, Kentucky ranks first nationwide for incidence (50 cases per 100,000 people) and fifth for mortality (about 17 deaths per 100,000 people). The Kentucky Colon Cancer Screening Program increased screening rates and reduced mortality since its launch. Yet, CRC remains a leading cause of death for Kentuckians. Risk factors for CRC include increasing age as well as a history of inflammatory bowel disease (IBD) and genetics. But what about nutrition? This article will discuss the role of specific nutrients as they relate to CRC risk and development
The importance of phase dynamics in generation of coherent structures
In magnetically confined plasmas (MCP), the transport of heat and particles is determined by collisional and anomalous processes caused by turbulence. A collective effort has been put into modelling the turbulent transport in plasmas using various drift wave (DW) models. However, it is evident that large-scale phenomena have a significant impact on overall transport. Heat transport can be mediated by coherent structures such as streamers and blobs through the formation of avalanche-like events that are intermittent in nature, i.e., localized in time but of large amplitude. Furthermore, at the same time, there are structures such as zonal flows (ZF) and GAMs that are non-linearly generated and mitigate turbulent transport by shearing turbulent eddies. A common denominator for these large-scale structures is the synchronization of smaller scale modes or events to a coherent structure, where phases align in a localized region of space and time. Interestingly, phase synchronization is prevalent in many other fields, such as biological clocks, physiological organisms, and chemical reactors. The dynamical evolution of amplitude and phases have been investigated through simplified equations derived from the Hasegawa - Wakatani (HW) system, where effects of synchronization are studied.Theoretical studies often deal with the amplitudes of the fluctuating quantities and assume that the phases are randomly distributed according to the random phase approximation (RPA) and thus disregard the dynamics of the phases [1,2]. In this approximation, dynamical amplitudes have a slow variation compared to the rapid change of the phases, which are distributed uniformly over a interval [3]. There have been a few general approaches to the randomness in turbulence: the RPA, the diagrammatic method by Wyld and the cumulant expansions, with the aim of systematically characterizing intermittent behavior. Unless a specific case is studied, the diagrammatic method has a drawback since there is no consistent small expansion parameter and no normalization procedure available. Moreover, the intuitive picture of the RPA approach is tempting and is thus widely adopted in turbulence theory. The underlying assumption of randomness in the RPA for the phases of Fourier modes in nonlinearly interacting waves cannot be justified since the phases as well as the amplitudes evolve due to non-linear interactions that act on the same time scales for both. Thus, the phases cannot be randomized faster than the amplitudes, see further discussion in Refs. [4,5]. Understanding the generation of coherent structures and the effects of these structures on transport and turbulence is therefore of crucial importance. In regard to plasma dynamics, simplified models are of interest, assuming an expansion of the state in amplitude and phase, i.e., , the basic dynamical equations yield one dynamical equation for the amplitude and one for the phase for each field in the model. In previous papers, models using the passive advected scalar [6] and the Burgers equation [1] where it was found that under certain conditions, the RPA assumption can be invalidated using a phase dependent force and the locking of phases may increase the energy transfer to other modes. The assumption of a fully stochastic phase state of the turbulence is more relevant for high values of scale separation with the energy spectrum following a decay rate. The dynamic of the three-body interactions between the phases in the non-linear Burgers’ turbulence shows that the phases lock intermittently. This is due to the k dependence of the coupling strength in the non-linear term which reduces strongly for high-k range due to the dampening effect of the dissipation which does not allow locking of the phases of the small scales. For lower scale dependence the asynchronized and synchronized phases differ significantly, and one could expect the formation of coherent modulations in the latter case. Moreover, the HW have been studied [7] and the work on the predator-prey model of DW – ZF dynamics, it is observed that synchronization may be transferred between the two populations [8].In this work, we investigate the role of phase dynamics for turbulent fluctuations in a set of direct numerical simulation (DNS) of homogeneous Taylor-Green driven turbulence, simple 2D rotating turbulence flow. The model is the forced incompressible magnetohydrodynamic (MHD) equations. It should be noted that in the study of coupled oscillators describing chemical reactors, the Kuramoto model has been established, and it has been shown that synchronization occurs when a certain threshold is exceeded. In this case the system is strongly forced to generate a vortex and where the phase locking between close neighbours can be quantified
The discrepancy between admission and discharge diagnoses: Underlying factors and potential clinical outcomes in a low socioeconomic country
Objective: The discrepancy between admission and discharge diagnosis can lead to possible adverse patient outcomes. There are gaps in integrated studies, and less is understood about its characteristics and effects. Therefore, this study was conducted to determine the frequency, characteristics, and outcomes of diagnostic discrepancies at admission and discharge.Design and data sources: This retrospective study reviewed the admitting and discharge diagnoses of adult patients admitted at Aga Khan University Hospital (AKUH), Internal Medicine Department between October 2018 and February 2019. The frequency and outcomes of discrepancies in patient diagnoses were noted among Emergency Department (ED) physician versus admitting physician, admitting physician versus discharge physician, and ED physician versus discharge physician for the full match, partial match, and mismatch diagnoses. The studied outcomes included interdepartmental transfer, Intensive Care Unit (ICU) transfer, in-hospital mortality, readmission within 30 days, and the length of stay. For simplicity, we only analyzed the factors for the discrepancy among ED physicians and discharge physicians.Results: Out of 537 admissions, there were 25.3-27.2% admissions with full match diagnoses while 18.6-19.4% and 45.3-47.9% had mismatch and partial match diagnoses respectively. The discrepancy resulted in an increased number of interdepartmental transfers (5-5.8%), ICU transfers (5.6-8.7%), in-hospital mortality (8-11%), and readmissions within 30 days in ED (14.4%-16.7%). A statistically significant difference was observed for the ward\u27s length of stay with the most prolonged stay in partially matched diagnoses (6.3 ± 5.4 days). Among all the factors that were evaluated for the diagnostic discrepancy, older age, multi-morbidities, level of trainee clerking the patient, review by ED faculty, incomplete history, and delay in investigations at ED were associated with significant discrepant diagnoses.Conclusions: Diagnostic discrepancies are a relevant and significant healthcare problem. Fixed patient or physician characteristics do not readily predict diagnostic discrepancies. To reduce the diagnostic discrepancy, emphasis should be given to good history taking and thorough physical examination. Patients with older age and multi-morbidity should receive significant consideration
Comparison Of Naproxen And Diacerein In The Treatment Of Knee Joint Osteoarthritis
Background: Knee osteoarthritis is a common disease in older age. Pain and limitation of movement are the main symptoms of knee osteoarthritis. Many pharmacological options are available for symptomatic relief but NSAIDs are mostly prescribed. Diacerein is also prescribed for osteoarthritis but data regarding its efficacy is still controversial. Moreover, studies regarding the comparison of diacerein with NSAIDs are deficient in Pakistan.
Objective: The objective of the study was to compare the clinical efficacy of naproxen (NSAID) with diacerein in treating knee osteoarthritis.
Methodology: Patients fulfilling inclusion criteria were included in the study. After written informed consent 60 patients of knee osteoarthritis were included in the study. They were divided randomly into two groups. Group A (n=30) was prescribed with tablet naproxen 500mg twice daily and group B (n=30) was given capsule diacerein 50mg twice daily for 12 weeks. Baseline VAS and WOMAC scores of the patients were noted. These scores were compared with scores achieved 12 weeks after intervention. Intra-group comparison of the scores was also carried out. SPSS version 23.0 was used for statistical analysis.
Results: WOMAC and VAS scores comparison of the two groups (A & B) before intervention showed an insignificant p-value that is 0.815 for the WOMAC score and 0.509 for the VAS score. After intervention means WOMAC score i.e.10.50 ± 2.46 of group A (treated with naproxen) was better than the mean 29.62 ± 7.03 of group B (treated with diacerein) showing significant p-value (< 0.001). Similarly mean VAS of group A 1.92 ± 0.58 improved more than the mean VAS of group B i.e 3.38 ± 0.75 with significant p-value (< 0.001). Intra-group comparison of the groups also showed a significant p-value.
Conclusion: Clinical efficacy of naproxen is better than diacerein in treating knee osteoarthritis
Performance of the TIMI risk score in predicting mortality after primary percutaneous coronary intervention in elderly women: Results from a developing country
Background: Despite women undergoing primary percutaneous coronary intervention (PPCI) having a higher rate of adverse outcomes than men, data evaluating prognostic risk scores, especially in elderly women, remains scarce. This study was conducted to validate the predictive value of Thrombolysis in Myocardial Infarction (TIMI) risk score in elderly female patients.
Materials and Methods: This was a retrospective analysis of elderly (\u3e65 years) female patients who underwent PPCI for ST-elevated myocardial infarction (STEMI) from October 2016 to September 2018. Patients\u27 demographic details and elements of TIMI risk score including age, co-morbidities, Killip classification; weight, anterior MI and total ischemic time were extracted from hospital records. The primary outcome was in-hospital mortality and post-discharge mortality reported on telephonic follow-up.
Results: A total of 404 elderly women with a median age of 70 years were included. The mean TIMI score was 5.25±1.45 with 40.3% (163) patients of TIMI score \u3e 5. In-hospital mortality rate was 6.4% (26) and was found to be associated with TIMI score (p\u3c0.001). The in-hospital mortality rate increased from 3.1% at TIMI score of 0-4 to 34.6% at the score of 8. On follow-up (16.43±7.40 months) of 211 (55.8%) patients, the overall mortality rate was 20.3%, and this was also associated with TIMI score (p\u3c0.001). The mortality rate increased from 5.6% at the score of 0-4 to 54.5% at the score of 8. The predictive values (area under the curve) of TIMI risk score for in-hospital and post-discharge mortality were 0.709 (95% CI 0.591-0.827; p \u3c0.001) and 0.689 (95% CI 0.608-0.770; p \u3c0.001), respectively.
Conclusion: Increased adverse outcomes were observed with higher TIMI risk score for in hospital and post-discharge follow-up. Therefore, the prognostic TIMI risk score is a robust tool in predicting both in-hospital as well as post-discharge mortality in elderly females
Antibiotic Sensitivity Patterns of Uropathogens in Children: The Current Trend
Background: The emergence of antibiotic-resistant infections has led to increased health care costs and mortality among children. The purpose of this study was to determine the causative organisms responsible for urinary tract infection and their antibiotic sensitivity pattern among pediatric patients of Rawalpindi/Islamabad.
Material and Methods: This cross-sectional study was carried out from June 2014 to June 2015, in the Department of Microbiology, Army Medical College, Rawalpindi, affiliated with the Military Hospital, Rawalpindi. About 270 urine samples of children with UTI were analyzed through Analytical Profile Index (API) 20E and biochemical test strips system. Their antibiotic susceptibility was determined by using standard techniques. Data were assessed and analyzed by SPSS version 17.
Results: Most common uropathogen was Escherichia coli (61.48%), followed by Proteus (15.5), Klebsiella (12.3%), Pseudomonas (4.5%), Enterococcus (3.7%) and Enterobacter (2.5%). Gram-negative rods, were most sensitive to imipenem (100%), Gentamycin (86%) and Amikacin (78.3%). They were least sensitive to Ampicillin (4.2%) and Norfloxacin (5.5%). Gram-positive cocci showed highest sensitivity for Vancomycin (100%) while displayed relatively less sensitivity for Nitrofurantoin (61.2%) and Gentamycin (48.7%). Cephalosporins also showed increased resistance with only 14% of gram-negative rods showing sensitivity to Cefotaxime. These organisms were highly resistant to Penicillin, showing a sensitivity of only 12.4%.
Conclusion: Decreased sensitivity against penicillin and cephalosporins is seen in uropathogens causing UTI in children. High sensitivity towards Nitrofurantoin makes this drug an empirical treatment in UTI. Regular surveillance of the developing resistance in uropathogens due to inappropriate use of antibiotic is necessary to reduce complication in children with urinary tract infection
A Rare Cause of Abdominal Pain in Adults: Meckel’s Diverticulitis
A 42-year-old man presented to the emergency room with complaints of periumbilical abdominal pain. A contrast-enhanced computed tomography revealed mucosal thickening in the small bowel of the right abdomen. There was a fairly large small bowel diverticulum associated with this segment. Findings were suggestive of small bowel diverticulitis or possibly focal enteritis. A Meckel’s diverticulum scan was diagnostic of Meckel’s diverticulum. The patient was then immediately taken to the operating room for emergency laparotomy and was intra-operatively found to have a thickened Meckel’s diverticulitis with adjacent small bowel obstruction. Meckel’s diverticulectomy was performed in continuity with the adjacent inflamed small bowel. The patient had a stable postoperative course without any complications and was discharged within 10 days. At the 3-month follow-up, the patient was well and remained asymptomatic
Impact of Endoscopic Retrograde Cholangiopancreatography on Laparoscopic Cholecystectomy
Background: For Common Bile Duct (CBD) stones an Endoscopic Retrograde Cholangiopancreatography (ERCP) is done prior to cholecystectomy. However, the ideal timing of cholecystectomy following ERCP is still a matter of debate. The aim of the present study was to observe the possible impact of ERCP on subsequent laparoscopic cholecystectomy.Material and Methods: This case control study was carried out in the Department of Surgery Unit 1, Holy Family hospital, Rawalpindi, from January 2018 to March 2019. A total number of 300 patients of symptomatic gallstones presenting to outpatient department were enrolled. Two groups, A (control group) and B (case group) were made on the basis of absence or presence of CBD stones, respectively. Group A underwent laparoscopic cholecystectomy within three working days of admission. In group B, ERCP was performed prior to cholecystectomy. Primary operating surgeon filled structured questionnaires for each patient immediately after surgery to compare operative differences between both groups. The baseline demographic details, clinical characteristics, laboratory investigations and peri-operative findings of both groups were recorded. Means and percentages were calculated with P value <0.05 regarded as statistically significant.Results: Majority of patients in this study were females (81%) of middle age group (42.5+15 years). Biliary colic was most common presenting complaint in both groups (33%). Dissection in triangle of Calot (P=0.00) and removal of gallbladder from liver bed (P=0.00) was significantly more difficult in group B than A. Intra-abdominal lavage was also done more often in post ERCP group (P=0.00). However procedural time did not vary between the two groups (P=0.19).Conclusions: Preoperative ERCP increases difficulty in laparoscopic cholecystectomy but does not prolong procedural time.Key words: Choledocholithiasis, Endoscopic retrograde cholangiopancreatography, Laparoscopic cholecystectom
Can the word superiority effect be modulated by serial position and prosodic structure?
In this study, we examined the word superiority effect in Arabic and English, two languages with significantly different morphological and writing systems. Thirty-two Arabic-English bilingual speakers performed a post-cued letter-in-string identification task in words, pseudo-words, and non-words. The results established the presence of the word superiority effect in Arabic and a robust effect of context in both languages. However, they revealed that, compared to the non-word context, word and pseudo-word contexts facilitated letter identification more in Arabic than in English. In addition, the difference between word and pseudo-word contexts was smaller in Arabic compared to English. Finally, there was a consistent first-letter advantage in English regardless of the context, while this was more consistent only in the word and pseudo-word contexts in Arabic. We discuss these results in light of previous findings and argue that the differences between the patterns reported for Arabic and English are due to the qualitative difference between word morphophonological representations in the two languages.Open Access funding provided by the Qatar National Library
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