A Group Theoretical Identification of Integrable Equations in the Li\'enard Type Equation x¨+f(x)x˙+g(x)=0\ddot{x}+f(x)\dot{x}+g(x) = 0 : Part II: Equations having Maximal Lie Point Symmetries

In this second of the set of two papers on Lie symmetry analysis of a class of Li\'enard type equation of the form $\ddot {x} + f(x)\dot {x} + g(x)= 0$, where over dot denotes differentiation with respect to time and $f(x)$ and $g(x)$ are smooth functions of their variables, we isolate the equations which possess maximal Lie point symmetries. It is well known that any second order nonlinear ordinary differential equation which admits eight parameter Lie point symmetries is linearizable to free particle equation through point transformation. As a consequence all the identified equations turn out to be linearizable. We also show that one can get maximal Lie point symmetries for the above Li\'enard equation only when $f_{xx} =0$ (subscript denotes differentiation). In addition, we discuss the linearising transformations and solutions for all the nonlinear equations identified in this paper.Comment: Accepted for publication in Journal of Mathematical Physic

Singularity Structure, Symmetries and Integrability of Generalized Fisher Type Nonlinear Diffusion Equation

In this letter, the integrability aspects of a generalized Fisher type equation with modified diffusion in (1+1) and (2+1) dimensions are studied by carrying out a singularity structure and symmetry analysis. It is shown that the Painlev\'e property exists only for a special choice of the parameter ($m=2$). A B\"acklund transformation is shown to give rise to the linearizing transformation to the linear heat equation for this case ($m=2$). A Lie symmetry analysis also picks out the same case ($m=2$) as the only system among this class as having nontrivial infinite dimensional Lie algebra of symmetries and that the similarity variables and similarity reductions lead in a natural way to the linearizing transformation and physically important classes of solutions (including known ones in the literature), thereby giving a group theoretical understanding of the system. For nonintegrable cases in (2+1) dimensions, associated Lie symmetries and similarity reductions are indicated.Comment: 8 page

Bilateral hypertrophic olivary nucleus degeneration on magnetic resonance imaging in children with Leigh and Leigh-like syndrome

Objective: Bilateral hypertrophic olivary degeneration on brain MRI has been reported in a few metabolic, genetic and neurodegenerative disorders, including mitochondrial disorders. In this report, we sought to analyse whether bilateral symmetrical inferior olivary nucleus hypertrophy is specifically associated with mitochondrial disorders in children. Methods: This retrospective study included 125 children (mean age, 7.6  ±  5 years; male:female, 2.6:1) diagnosed with various metabolic and genetic disorders during 2005–2012. The routine MRI sequences (T1 weighted, T2 weighted and fluid-attenuated inversion–recovery sequences) were analysed for the presence of bilateral symmetrical olivary hypertrophy and central tegmental tract or dentate nuclei signal changes. The other imaging findings and the final diagnoses were noted. Results: The cohort included patients with Leigh and Leigh-like syndrome (n = 25), other mitochondrial diseases (n = 25), Wilson disease (n = 40), Type 1 glutaric aciduria (n = 14), maple syrup urine disease (n = 13), giant axonal neuropathy (n = 5) and L-2 hydroxy glutaric aciduria (n = 3). Bilateral inferior olivary nucleus hypertrophy was noted in 10 patients, all of whom belonged to the Leigh and Leigh-like syndrome group. Conclusion: Bilateral hypertrophic olivary degeneration on MRI is relatively often, but not routinely, seen in children with Leigh and Leigh-like syndrome. Early detection of this finding by radiologists and physicians may facilitate targeted metabolic testing in these children

The Role of Palliative Care Consultation in Withdrawal of Life-Sustaining Treatment among ICU Patients Receiving Veno-Venous Extracorporeal Membrane Oxygenation (VV-ECMO): A Retrospective Case-Control Study

Background: Extracorporeal membrane oxygenation (ECMO) has extended the survivability of critically ill patients beyond their unsupported prognosis and has widened the timeframe for making an informed decision about the goal of care. However, an extended time window for survival does not necessarily translate into a better outcome and the sustaining treatment is ultimately withdrawn in many patients. Emerging evidence has implicated the determining role of palliative care consult (PCC) in direction of the care that critically ill patients receive. Objective: To evaluate the impact of PCC in withdrawal of life-sustaining treatment (WOLST) among critically ill patients, who were placed on venovenous ECMO (VV-ECMO) at the intensive care unit (ICU) of a tertiary care hospital. Methods: In a retrospective observational study, electronic medical records of 750 patients admitted to the ICU of our hospital between January 1, 2015, and October 31, 2021, were reviewed. Data was collected for patients on VV-ECMO, for whom WOLST was withdrawn during the ICU stay. Clinical characteristics and the underlying reasons for WOLST were compared between those who received PCC (PCC group) and those who did not (non-PCC group). Results: A total of 95 patients were included in our analysis, 63 in the PCC group and 32 in the non-PCC group. The average age of the study population was 48.8 ± 12.6 years, and 64.2% were male. There was no statistically significant difference between the two groups in terms of demographics or clinical characteristics at the time of ICU admission. The average duration of ICU stay and VV-ECMO were 14.1 ± 19.9 days and 9.4 ± 16.6 days, respectively. The number of PCC visits was correlated with the length of ICU stay. The average duration of ICU stay (40.3 ± 33.2 days vs 27.8 ± 19.3 days, P = .05) and ECMO treatment (31.9 ± 27 days vs 18.6 ± 16.1 days, P = .01) were significantly longer in patients receiving PCC than those not receiving PCC. However, the frequency of life sustaining measures or the underlying reasons for WOLST did not significantly differ between the two groups (P \u3e .05). Conclusion: Among ICU patients requiring ECMO support, longer duration of ICU stay and treatment with a higher number of life-sustaining measures seemed to be correlated with the number of PCC visits. The underlying reasons for WOLST seem not to be affected by PCC

The Role of Palliative Care Consultation in Withdrawal of Life-Sustaining Treatment among ICU Patients Receiving Veno-Venous Extracorporeal Membrane Oxygenation (VV-ECMO): A Retrospective Case-Control Study

Background: Extracorporeal membrane oxygenation (ECMO) has extended the survivability of critically ill patients beyond their unsupported prognosis and has widened the timeframe for making an informed decision about the goal of care. However, an extended time window for survival does not necessarily translate into a better outcome and the sustaining treatment is ultimately withdrawn in many patients. Emerging evidence has implicated the determining role of palliative care consult (PCC) in direction of the care that critically ill patients receive. Objective: To evaluate the impact of PCC in withdrawal of life-sustaining treatment (WOLST) among critically ill patients, who were placed on venovenous ECMO (VV-ECMO) at the intensive care unit (ICU) of a tertiary care hospital. Methods: In a retrospective observational study, electronic medical records of 750 patients admitted to the ICU of our hospital between January 1, 2015, and October 31, 2021, were reviewed. Data was collected for patients on VV-ECMO, for whom WOLST was withdrawn during the ICU stay. Clinical characteristics and the underlying reasons for WOLST were compared between those who received PCC (PCC group) and those who did not (non-PCC group). Results: A total of 95 patients were included in our analysis, 63 in the PCC group and 32 in the non-PCC group. The average age of the study population was 48.8 ± 12.6 years, and 64.2% were male. There was no statistically significant difference between the two groups in terms of demographics or clinical characteristics at the time of ICU admission. The average duration of ICU stay and VV-ECMO were 14.1 ± 19.9 days and 9.4 ± 16.6 days, respectively. The number of PCC visits was correlated with the length of ICU stay. The average duration of ICU stay (40.3 ± 33.2 days vs 27.8 ± 19.3 days, P = .05) and ECMO treatment (31.9 ± 27 days vs 18.6 ± 16.1 days, P = .01) were significantly longer in patients receiving PCC than those not receiving PCC. However, the frequency of life sustaining measures or the underlying reasons for WOLST did not significantly differ between the two groups (P \u3e .05). Conclusion: Among ICU patients requiring ECMO support, longer duration of ICU stay and treatment with a higher number of life-sustaining measures seemed to be correlated with the number of PCC visits. The underlying reasons for WOLST seem not to be affected by PCC

Performance characteristics of positive and negative delayed feedback on chaotic dynamics of directly modulated InGaAsP semiconductor lasers

The chaotic dynamics of directly modulated semiconductor lasers with delayed optoelectronic feedback is studied numerically. The effects of positive and negative delayed optoelectronic feedback in producing chaotic outputs from such lasers with nonlinear gain reduction in its optimum value range is investigated using bifurcation diagrams. The results are confirmed by calculating the Lyapunov exponents. A negative delayed optoelectronic feedback configuration is found to be more effective in inducing chaotic dynamics to such systems with nonlinear gain reduction factor in the practical value range.Comment: 18 pages, 16 figures. To appear In Pramana - journal of physic

Prevalence of marine litter along the Indian beaches : A preliminary account on its status and composition

Beach litter are man-made objects discarded directly or indirectly. This study brings out synoptic picture of status and composition of beach litter from 254 selected beaches along the maritime States of Peninsular coast of India as well as the Union Territories of Andaman and Lakshadweep Islands from the one time observation conducted between October 2013 and January 2014 for the first time. These beaches were classified and graded with colour codes according to the levels of beach litter. Beach litter from different maritime States and the UTs showed that Odisha coast has the lowest (0.31 g/m2) quantity and Goa coast (205.75 g/m2) the highest quantity of beach debris. Archipelagic coasts of Andamans as well as Lakshadweep recorded values higher than Kerala, Tamil Nadu, Andhra Pradesh, Odisha and West Bengal. Samples of debris collected from beaches revealed that all the items were domestic and anthropogenic discards. Plastic litters such as single use carry bags and sachets of soft drinks, edible oils, detergents, beverages, cases of cosmetics, toothpaste, PET bottles, ice cream containers etc., recorded highest mean of 25.47g/m2 from Goa coast and the lowest (0.08 g/m2) from Odisha. The relative percentage of mean values of plastic (B group) items in beach debris along the Indian coast registered highest mean percentage from Maharashtra (81 %) and the lowest mean from beaches of Andhra Pradesh (7%). The two island Union Territories registered 40% (Lakshadweep) and 47% (Andamans) of plastics over the total debris, while the national average was only 14%. Available online at: www.mbai.org.in doi: 10.6024/jmbai.2017.59.1.1953-03 Out of the total 254 beaches surveyed, 51 beaches were graded as very clean with green (<1 g/m2) colour, 122 beaches were graded as Clean and depicted by blue colour. Beaches of very clean grade (<1 g/m2) were found in Kerala (17), Maharashtra (12), Tamil Nadu (2), Andhra Pradesh (4), Odisha (7) and West Bengal (3). Whereas extremely littered beaches (>100 g/m2) were found in Karnataka (13), Goa, Gujarat, and Andaman Island. With reference to the coastal population and per capita share of beach debris, Goa registered highest values (40.97 kg/head) and the Odisha coast registered the lowest values (0.005 kg/head)

Targeted Deletion of Neuropeptide Y (NPY) Modulates Experimental Colitis

Neurogenic inflammation plays a major role in the pathogenesis of inflammatory bowel disease (IBD). We examined the role of neuropeptide Y (NPY) and neuronal nitric oxide synthase (nNOS) in modulating colitis.Colitis was induced by administration of dextran sodium sulphate (3% DSS) or streptomycin pre-treated Salmonella typhimurium (S.T.) in wild type (WT) and NPY (NPY(-/-)) knockout mice. Colitis was assessed by clinical score, histological score and myeloperoxidase activity. NPY and nNOS expression was assessed by immunostaining. Oxidative stress was assessed by measuring catalase activity, glutathione and nitrite levels. Colonic motility was assessed by isometric muscle recording in WT and DSS-treated mice.DSS/S.T. induced an increase in enteric neuronal NPY and nNOS expression in WT mice. WT mice were more susceptible to inflammation compared to NPY(-/-) as indicated by higher clinical & histological scores, and myeloperoxidase (MPO) activity (p<0.01). DSS-WT mice had increased nitrite, decreased glutathione (GSH) levels and increased catalase activity indicating more oxidative stress. The lower histological scores, MPO and chemokine KC in S.T.-treated nNOS(-/-) and NPY(-/-)/nNOS(-/-) mice supported the finding that loss of NPY-induced nNOS attenuated inflammation. The inflammation resulted in chronic impairment of colonic motility in DSS-WT mice. NPY -treated rat enteric neurons in vitro exhibited increased nitrite and TNF-alpha production.NPY mediated increase in nNOS is a determinant of oxidative stress and subsequent inflammation. Our study highlights the role of neuronal NPY and nNOS as mediators of inflammatory processes in IBD