Multiwavelength operation of erbium-doped fiber lasers by periodic filtering and phase modulation

This paper explains the principles behind multiwavelength operation of an erbium-doped fiber laser (EDFL) under the combined effect of cavity phase modulation and periodic wavelength filtering. A mathematical model is developed to simulate the behaviour of the multiwavelength EDFL, both in time and frequency domains. The effects of various parameters such as pump power, filter channel spacing, modulation index and frequency are observed and explained. An all-fiber EDFL was constructed, using a piezo-transducer-based phase modulator and a Sagnac loop periodic filter, to validate the theoretical results. The effects of pump power, modulation frequency and modulation index were monitored experimentally, justifying the theoretical explanation. The multiwavelength EDFL has several potential applications in fiber sensing due to its flexible all-fiber design

Larval rearing and fry raising of Pangasius sutchi(Fowler)

Pangasius sutchi were artificially bred for determining the hatching success and larval growth response to live food in relation to varying stocking densities. The fertilized eggs were hatched out with successful hatching rates ranging between 60 and 63%. Newly hatched larvae of 4.4 mm average length were reared using Tubifex as live food in metallic trays with water temperature of 27 to 29.5°C and dissolved oxygen level of 3.88 to 6.22 mg/1 for 6-day with an average survival rate of75.56±13.25%. The P. sutchifry of9- day old were further reared using Tubifex in the polythene covered metallic trays at the stocking densities of 2-7 fry per litre of water for a period of 14 day. P. sutchi fry raising at 4 individual per litre of water for 14 day gives better results in terms of survival and growth

Identification of arsenic hyperaccumulating plants for the development of phytomitigation technology

Out of 35 plant samples collected from different districts of Bangladesh, only 14 species were arsenic (As) hyper accumulating. Species identified as hyperaccumulating were barnyard grass, water cress, cockle bur, Azolla, rice, water lettuce, water taro, taro, fern, water hyacinth and alligator weed. Maximum accumulation of As was in barnyard grass at 61.3 ppm, 67.9 ppm and 67.8 ppm in root, shoot and grain, respectively. From the chemical analysis of 35 naturally grown plants barnyard grass can mitigate soil As contamination. Water hyacinth, water cress, water lettuce and Azolla were able to absorb As from contaminated stagnant water. From this study an idea for phytoremediation of As by naturally grown plants has been found

Raspodjela pp\u27DDT u nekim dijelovima mozga u štakora tretiranih diazinonom

The effect of diazinon, given intraperitoneally, on the distribution of pp\u27DDT was determined in certain brain regions of rats. pp\u27DDT concentration expressed per gram of wet weight was highest in the corpus striatum (2575 ng/g) followed by those in the cerebellum (1850 ng/g) and in the cortex (990 ng/g). Pretreatment with diazinon increased pp\u27DDT accumulation in various brain regions by about 20 per cent (corpus striatum 2995 ng/g; cerebellum 2240 ng/g and cortex 1245 ng/g) and reduced cholinesterase activity by 50 - 70 per cent.Određivan je učinak intraperitonealno davanog diazinona na raspodjelu pp\u27DDT u nekim dijelovima mozga u štakora. Koncentracija pp\u27DDT po gramu težine mozga bila je najviša u korpusu strijatumu (2575 ng/g), zatim malom mozgu (1850 ng/g) i kori velikog mozga (990 ng/g). Prethodni tretman diazinonom povećao je akumulaciju pp\u27DDT u regijama mozga štakora za oko 20% (korpus strijatum 2995 ng/g, mali mozak 2240 ng/g, kora velikog mozga 1245 ng/g). Aktivnost acetilkolinesteraze mozga smanjila se za 50 do 70%

Ionic Toxicity Assessment of Water Sources and their Suitability for Irrigation, Drinking, Livestock and Industrial Purposes

A study was conducted to assess of the degree of ionic toxicity on the basis of standard criteria for irrigation, drinking, livestock, poultry, aquaculture and industrial purposes of 20 ground water sources in Kushtia, Bangladesh. The chemical analysis included pH, electrical conductivity (EC), total dissolved solids (TDS) and major ionic constituents like Ca, Mg, K, Na, Fe, Mn, B, As, Cu, PO4, CO3, HCO3, SO4 and Cl. sodium adsorption ratio(SAR), soluble sodium percentage (SSP), residual sodium carbonate(RSC) and hardness(HT) were also calculated. The pH (6.93 to 7.63) showed slightly acidic to neutral.Ca (23.8 to 100.2 mg L-1), Mg (20.3 to 57 mg L-1), Na (16.49 to 52.30 mg L-1), K (0.36 to 5.76 mg L-1), HCO3 (132.51 to 347.30 mg L-1) and Cl- (36.9 to 76.2 mg L-1) were predominant along with Mn, Cu and B in lesser amounts. Fe, As, PO4, SO4 and CO3 were found trace to little amounts. The TDS was rated as ‘fresh water’. EC and SAR were ‘medium’ and ‘high salinity’ (C2 and C3) classes and ‘low alkali hazard’ (S1) class, combinedly expressed as C2S1 and C3S1. SSP was of ‘excellent’, ‘good’ and ‘permissible’ categories. Waters were free from RSC and belonged to ‘suitable’ category for irrigation. The waters were classified as ‘hard’, ‘very hard’ and ‘medium hard’ based on hardness (HT).The toxicities of B, Mn and Cl were not found in the study area for irrigation but HCO3, CO3, Fe and As toxicities were found in some sources. Iron content of 7 samples was ‘unsuitable’ for drinking, livestock, poultry and 7 samples were unsuitable for aquaculture usage. Manganese content of all samples was ‘suitable’ for drinking and livestock consumption. Both Fe and Mn content of all samples were ‘problematic’ for industrial usage. Arsenic status of 9 water samples was ‘suitable’ for drinking. Chloride content most of the samples was ‘toxic’ for livestock but all samples were ‘unfit’ for aquaculture. Sulphate of all samples was ‘suitable’ for drinking, livestock, poultry, aquaculture and industrial usage

Mass spectrometry based metabolomics comparison of liver grafts from donors after circulatory death (DCD) and donors after brain death (DBD) used in human orthotopic liver transplantation

Use of marginal liver grafts, especially those from donors after circulatory death (DCD), has been considered as a solution to organ shortage. Inferior outcomes have been attributed to donor warm ischaemic damage in these DCD organs. Here we sought to profile the metabolic mechanisms underpinning donor warm ischaemia. Non-targeted Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry metabolomics was applied to biopsies of liver grafts from donors after brain death (DBD; n = 27) and DCD (n = 10), both during static cold storage (T1) as well as post-reperfusion (T2). Furthermore 6 biopsies from DBD donors prior to the organ donation (T0) were also profiled. Considering DBD and DCD together, significant metabolic differences were discovered between T1 and T2 (688 peaks) that were primarily related to amino acid metabolism, meanwhile T0 biopsies grouped together with T2, denoting the distinctively different metabolic activity of the perfused state. Major metabolic differences were discovered between DCD and DBD during cold-phase (T1) primarily related to glucose, tryptophan and kynurenine metabolism, and in the post-reperfusion phase (T2) related to amino acid and glutathione metabolism. We propose tryptophan/kynurenine and S-adenosylmethionine as possible biomarkers for the previously established higher graft failure of DCD livers, and conclude that the associated pathways should be targeted in more exhaustive and quantitative investigations

Higher education is associated with a lower risk of dementia after a stroke or TIA

__Background:__ Higher education is associated with a lower risk of dementia, possibly because of a higher tolerance to subclinical neurodegenerative pathology. Whether higher education also protects against dementia after clinical stroke or transient ischemic attack (TIA) remains unknown. __Methods:__ Within the population-based Rotterdam Study, 12,561 participants free of stroke, TIA and dementia were followed for occurrence of stroke, TIA and dementia. Across the levels of education, associations of incident stroke or TIA with subsequent development of dementia and differences in cognitive decline following stroke or TIA were investigated. __Results:__ During 124,862 person-years, 1,463 persons suffered a stroke or TIA, 1,158 persons developed dementia, of whom 186 developed dementia after stroke or TIA. Risk of dementia after a stroke or TIA, compared to no stroke or TIA, was highest in the low education category (hazards ratio [HR] 1.46, 95% CI 1.18-1.81) followed by intermediate education category (HR 1.36, 95% CI 1.03-1.81). No significant association was observed in the high education category (HR 0.62, 95% CI 0.25-1.54). In gender stratified analyses, decrease in risk of dementia with increasing education was significant only in men. __Conclusion:__ Higher education is associated with a lower risk of dementia after stroke or TIA, particularly in men, which might be explained by a higher cognitive reserve

Predictors and frequency of conduction disturbances after open-heart surgery

Introduction: The risk of developing conduction disturbances after coronary bypass grafting (CABG) or valvular surgery has been well established in previous studies, leading to permanent pacemaker implantation in about 2 to 3 of patients, and in 10 of patients undergoing repeat cardiac surgery. We sought to determine the incidence, features and predictors of conduction disorders in the immediate post-operative period of patients subjected to open-heart surgery, and the need for permanent pacemaker implantation. Material and Method: We prospectively studied 374 consecutive patients who underwent open-heart surgery in our institution: coronary artery bypass (CABG) (n=128), Mitral valve replacement(MVR) (n=18), aortic valve replacement(AVR) (n=21), MVR and AVR(n=56), repair of ventricular septal defect (VSD) (n=51), repair of tetralogy of Fallot (TOF) (n=57),CABG and valvular surgery (n=6), others (n=37). Results: Among 374 patients included in our study (mean age 34.46±25.68; 146 males), 192 developed new conduction disorders: symptomatic sinus bradycardia in 8, atrial fibrillation with slow ventricular response (AF) in 4.5, first-degree atrioventricular block (AVB)in 6.4, second-degree AVB in 0.3 third-degree AVB in 7, new right bundle branch block (RBBB) in 33, and new left bundle branch block (LBBB) in 2.1. In 5.6 patients, a permanent pacemaker was implanted, 47.6 of them underwent valvular surgery. In 44.1 of patients the conduction defects occurred in the first 48 hr. after surgery. In CABG group, 29.7 of patients developed new conduction disturbances; the most common of them was symptomatic sinus bradycardia. After valvular surgery 44.2 of patients developed conduction disturbances, of those the most common was atrial fibrillation with slow ventricular response. After VSD and TOF repair, the most common conduction disturbance was new RBBB. Perioperative myocardial infarction (MI) occurred in 1.9 of patients. The occurrence conduction disturbance was compared with patient age, sex, occurrence of perioperative MI, ejection fraction (EF), postoperative use of �-adernergic receptor blocking agents and digitalis and type of cardiac surgery. By regression analysis there was a correlation between type of surgery and new conduction defects, being significant for CABG and TOF repair. Only the occurrence of perioperative MI was related to PPM implantation. Conclusion: Irreversible AVB requiring a PPM is an uncommon complication after open-heart surgery. Peri-operative MI is a risk factor

Subnational inequalities in years of life lost and associations with socioeconomic factors in pre-pandemic Europe, 2009–19:an ecological study

Background: Health inequalities have been associated with shorter lifespans. We aimed to investigate subnational geographical inequalities in all-cause years of life lost (YLLs) and the association between YLLs and socioeconomic factors, such as household income, risk of poverty, and educational attainment, in countries within the European Economic Area (EEA) before the COVID-19 pandemic. Methods: In this ecological study, we extracted demographic and socioeconomic data from Eurostat for 1390 small regions and 285 basic regions for 32 countries in the EEA, which was complemented by a time-trend analysis of subnational regions within the EEA. Age-standardised YLL rates per 100 000 population were estimated from 2009 to 2019 based on methods from the Global Burden of Disease study. Geographical inequalities were assessed using the Gini coefficient and slope index of inequality. Socioeconomic inequalities were assessed by investigating the association between socioeconomic factors (educational attainment, household income, and risk of poverty) and YLLs in 2019 using negative binomial mixed models. Findings: Between Jan 1, 2009, and Dec 31, 2019, YLLs lowered in almost all subnational regions. The Gini coefficient of YLLs across all EEA regions was 14·2% (95% CI 13·6–14·8) for females and 17·0% (16·3 to 17·7) for males. Relative geographical inequalities in YLLs among women were highest in the UK (Gini coefficient 11·2% [95% CI 10·1–12·3]) and among men were highest in Belgium (10·8% [9·3–12·2]). The highest YLLs were observed in subnational regions with the lowest levels of educational attainment (incident rate ratio [IRR] 1·19 [1·13–1·26] for females; 1·22 [1·16–1·28] for males), household income (1·35 [95% CI 1·19–1·53]), and the highest poverty risk (1·25 [1·18–1·34]). Interpretation: Differences in YLLs remain within, and between, EEA countries and are associated with socioeconomic factors. This evidence can assist stakeholders in addressing health inequities to improve overall disease burden within the EEA. Funding: Research Council of Norway; Development, and Innovation Fund of Hungary; Norwegian Institute of Public Medicine; and COST Action 18218 European Burden of Disease Network.</p