Mechanisms Of Telomere Maintenance In Trypanosoma Brucei

Telomeres are a nucleoprotein structure at the end of the chromosome and are essential for genome integrity and chromosome stability. Telomere lengths are primarily maintained by a telomerase-mediated pathway but can be maintained by a homologous recombination-mediated pathway. However, detailed mechanisms of telomere maintenance are still unclear in many eukaryotes, including an important human pathogen, Trypanosoma brucei. Telomeres can be elongated by telomerase in T. brucei, a causative agent of fatal sleeping sickness in humans and nagana in cattle. T. brucei evades host immune response by regularly switching its major surface antigen, variant surface glycoprotein (VSG), a process known as antigenic variation. The telomere structure and telomere proteins play critical roles in T. brucei pathogenesis. In mammalian, yeast, and plant cells, ssDNA binding proteins with OB-fold domains play important roles in coordinating telomere G- and C-strand syntheses. However, no such protein has been described in T. brucei to be specifically associated with the telomere. We identified POLIE, an A-type DNA polymerase, as a crucial telomere complex component in T. brucei and essential in maintaining telomere integrity in T. brucei. Depletion of POLIE in T. brucei leads to an increased amount of DNA damage at telomere/subtelomere, increased frequency of gene conversion-mediated VSG switching, and an increased amount of the telomeric circles (T-circles), suggesting a potential role of POLIE in suppressing DNA recombination at the telomere and the subtelomere. However, I find that telomeric and subtelomeric DNA recombination is unlikely to be mediated by the increased telomeric R-loop level as the telomeric repeat-containing RNA (TERRA) level is significantly lower in POLIE-depleted cells. The telomere G-rich 3’overhangs are dramatically elongated in POLIE-depleted cells, indicating a potential role of POLIE to coordinate telomere G- and C-strand syntheses and suggesting that the long telomere 3’ overhang can induce more telomeric and subtelomeric recombination. In addition, I find that POLIE inhibits telomerase-dependent telomere G-strand extension, identifying POLIE as the first telomere protein that potentially suppresses telomerase in T. brucei. Moreover, depletion of POLIE greatly increases the amount of telomeric C-circles which can be derived from replication stress in the telomere C-strand. Importantly, the elongated telomere 3’ overhang and elevated telomeric C-circle level phenotypes are independent of the telomerase, which suggests that POLIE may promote the telomere C-strand synthesis. Therefore, we identified that POLIE plays a major role in suppressing telomere recombination, coordinating telomerase-mediated telomere G-strand extension, and telomere C-strand synthesis, and maintaining telomere integrity in T. brucei

Technical Efficiency of Freshwater Aquaculture and its Determinants in Tripura, India

Freshwater aquaculture is an important and promising sector of the economy of Tripura State. The biophysical potential for growth in freshwater aquaculture in the state is still far from exhaustion and a faster development is required to meet the growth in demand for fish. This paper has assessed the level of technical efficiency and its determinants of small-scale fish production in the West Tripura district of the state of Tripura, India. The study is based on the cross-sectional primary data collected from 101 fish farmers through a multi-stage random sampling method. The paper has employed stochastic production frontier approach, and has followed both one-stage and two-stage procedures to analyze the determinants of TE. The TE ranges between 0.21 and 0.96 with mean of 0.66 and median of 0.71. The study has revealed the Cobb-Douglas form of stochastic frontier production function is more dependable than that of translog form under the farming conditions in the West Tripura district of Tripura state. One-stage procedure with technical inefficiency model gives reliable estimates of coefficients of stochastic frontier production function than that of two-stage procedure. Seed quality has been found as an important determinant of TE. The study has suggested that the state government needs to play a role to ascertain the supply of quality fish fingerlings at adequate time and quantity to the farmers in the study area.Agricultural and Food Policy,

DEPRESSION IN PREGNANCY - CONSEQUENCES AND TREATMENT MODALITIES

Depression is a mood disorder which can affect 1 in every 4 women at some point of life even during pregnancy. Depression is most often not properly diagnosed during pregnancy as it is assumed by people to be just another type of imbalance in hormones. But this assumption can be very dangerous to the mother and the fetus. The health care professionals are very cautious about the treatment for depression in pregnancy as both uses of antidepressant and untreated depression in pregnancy can lead to risks for the unborn baby. This review focuses on the complications associated with both treated and untreated depression during pregnancy. In addition, if the treatment is inevitable, then factors such as teratogenesis, withdrawal symptoms, neurobehavioral effects, risk of untreated and risk of discontinuing the medication need to be considered before selecting the suitable therapy.Keywords: Pregnancy, Depression, Drug-therapy, Fetal toxicit

Studying the factors affecting urban dispersion in mashhad metropolis

In recent decades, urban population in the world, especially in southern countries, hasexceeded rural population that has brought about urban land expansion followed bydispersion phenomenon, the result of which has created problems in environmental,economic, social, and physical aspects including increased air pollution, potentialdeterioration within the city, and destruction of farms and open spaces. The aim of thisstudy is to investigate the roots of dispersion in Mashhad metropolis in order to identifysolutions to control this problem. The tools used in this research were GIS software formapping, quantitative methods of Holdren Model, urban primacy index, and area topopulation growth rate for review and analysis, and at first by examining area topopulation growth rate, Mashhad- developmental process map, Holdren model, andgross population-density dispersion model of this city was shown.Then the roots of dispersion including market failure (checking the price of land), technology, natural population-growth process, and migration were analyzed. To study the dispersion in Mashhad metropolis, Holdren model was used, according to which only 34% of dispersion is population growth, and 66% of urban growth is related to horizontal growth. This is indicative of the dispersion in Mashhad metropolis, and the most important reasons are low price of housing in the suburb, ignoring social costs arising from it, increasing percentage of car ownership, gradual population growth inMashhad due to political priority, and the concentration of facilities in it that are thereason of increase in immigration to this metropolis. To deal with this phenomenondispersion, it is proposed that patterns of sustainable development such as  transportbased development and compact city are used.Key words: urban dispersion, technology, roots of Mashhad dispersion, the price ofland, immigratio

The Effectiveness of Subgingival Scaling and Root Planing in Calculus Removal

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141524/1/jper0119.pd

Application of simultaneous active and reactive power modulation of SMES unit under unequal mode for power system stabilization

Vol.14, No. 2, May 199

Biofilter for generation of concentrated sulphuric acid from H2S

Biofilters are used for the conversion of odorous hydrogen sulphide to odourless sulphate in wastewater treatment plants under the right conditions of moisture and pH. One of the consequences of maintaining the suitable pH and moisture content is the production of large volumes of weakly acidic leachate. This paper presents a biofilter with a maximum H2S elimination capacity of 16.3 g m−3 h−1 and removal efficiency greater than 95 % which produces small volumes (1 mL of solution L−1 of reactor day−1) of sulphuric acid with a concentration greater than 5.5 M after 150 days of continuous operation. The concentrated sulphuric acid was produced by intermittently trickling a minimum amount of nutrient solution down the upflow biofilter which created a moisture and pH gradient within the biofilter resulting in an environment at the top for the bacterial conversion of H2S, while sulphuric acid was accumulated at the base. Genetic diversity profiling of samples taken from different sections of the biofilter confirms that the upper sections of the biofilter had the best environment for the bacteria to convert H2S to sulphate. The formation of concentrated sulphuric acid presents an opportunity for the recovery of sulphur from the waste stream as a usable product