Steroidi i poliketidi iz kore biljke Uvaria hamiltonii

Two known steroids, stigmasterol and 6beta-hydroxystigmasta-4,22-dien-3-one (1) and two unusual polyketides, cis-4-hydroxymellein (2) and trans-4-hydroxymellein (3) were isolated from the stem bark of Uvaria hamiltonii. The structures of the compounds were elucidated independently by high-resolution 2D-NMR techniques and confirmed by comparison with previously reported values.Dva poznata steroida, stigmasterol i 6-hidroksistigmasta-4,22-dien-3-on (1) i dva neuobičajena poliketida, cis-4-hidroksimelein (2) i trans-4-hidroksimelein (3) izolirana su iz kore biljke Uvaria hamiltonii. Strukture spojeva određene su neovisno 2D-NMR spektroskopijom visoke rezolucije i usporedbom s literaturnim podacima

Highly conserved type 1 pili promote enterotoxigenic E. coli pathogen-host interactions

Enterotoxigenic Escherichia coli (ETEC), defined by their elaboration of heat-labile (LT) and/or heat-stable (ST) enterotoxins, are a common cause of diarrheal illness in developing countries. Efficient delivery of these toxins requires ETEC to engage target host enterocytes. This engagement is accomplished using a variety of pathovar-specific and conserved E. coli adhesin molecules as well as plasmid encoded colonization factors. Some of these adhesins undergo significant transcriptional modulation as ETEC encounter intestinal epithelia, perhaps suggesting that they cooperatively facilitate interaction with the host. Among genes significantly upregulated on cell contact are those encoding type 1 pili. We therefore investigated the role played by these pili in facilitating ETEC adhesion, and toxin delivery to model intestinal epithelia. We demonstrate that type 1 pili, encoded in the E. coli core genome, play an essential role in ETEC virulence, acting in concert with plasmid-encoded pathovar specific colonization factor (CF) fimbriae to promote optimal bacterial adhesion to cultured intestinal epithelium (CIE) and to epithelial monolayers differentiated from human small intestinal stem cells. Type 1 pili are tipped with the FimH adhesin which recognizes mannose with stereochemical specificity. Thus, enhanced production of highly mannosylated proteins on intestinal epithelia promoted FimH-mediated ETEC adhesion, while conversely, interruption of FimH lectin-epithelial interactions with soluble mannose, anti-FimH antibodies or mutagenesis of fimH effectively blocked ETEC adhesion. Moreover, fimH mutants were significantly impaired in delivery of both heat-stable and heat-labile toxins to the target epithelial cells in vitro, and these mutants were substantially less virulent in rabbit ileal loop assays, a classical model of ETEC pathogenesis. Collectively, our data suggest that these highly conserved pili play an essential role in virulence of these diverse pathogens

Steroidi i poliketidi iz kore biljke Uvaria hamiltonii

Two known steroids, stigmasterol and 6beta-hydroxystigmasta-4,22-dien-3-one (1) and two unusual polyketides, cis-4-hydroxymellein (2) and trans-4-hydroxymellein (3) were isolated from the stem bark of Uvaria hamiltonii. The structures of the compounds were elucidated independently by high-resolution 2D-NMR techniques and confirmed by comparison with previously reported values.Dva poznata steroida, stigmasterol i 6-hidroksistigmasta-4,22-dien-3-on (1) i dva neuobičajena poliketida, cis-4-hidroksimelein (2) i trans-4-hidroksimelein (3) izolirana su iz kore biljke Uvaria hamiltonii. Strukture spojeva određene su neovisno 2D-NMR spektroskopijom visoke rezolucije i usporedbom s literaturnim podacima

Small-Scale Turkey Farming in Bangladesh: Farming Practices, Profitability and Supply Chain Mapping

The study was conducted to know the existing turkey production system, supply chain mapping, and identifying the prospects and problems of turkey rearing in some selected areas of Bangladesh during October 2019 to December 2019. A total of 100 turkey raisers were surveyed following convenience method of sampling technique. The primary data were collected, analyzed accordingly and tabular presentation method was applied with the help of simple descriptive statistical measures e.g. frequency distributions, percentage, sum and means to illustrating the results. Profitability analysis was done on the basis of variable cost, fixed cost, return by using arithmetic means and percentages. The study revealed that 87 male and 13 female respondents were surveyed, of them cent percent found educated. About 56% turkey keeper’s main occupation was business, 27% service and 12% in farming while 88.57% involved with farming as secondary sources of income. Average landholding for homestead, cultivable and non-cultivable was 24.40, 129.71 and 29.47 decimal, respectively. About 59% farms started for commercial purpose, 32% for non-commercial purpose and 9% for both. About 60% respondents kept less than 50 turkeys and only 2% kept 501-1000 turkeys. Among the surveyed farms55% stopped their operation and 45% farms found running their business. Among the running farms cent percent were small-scale group. The average feed intake was 192.13 grams per day per bird at 20 weeks of age. Turkey laid on an average 139 eggs a year irrespective of variety and for hatching poults, the fertility and hatchability rate found between 65 to 100% and 50 to 90%, respectively. About 28% farmers experienced the deaths of turkey because of Cold, Pox, Ranikhet, Bird flu and unknown cases and 69.47% farmers took veterinary advice from Upazila Livestock Hospital and rest from other sources. Farmers to consumers were the most common and widely used marketing channel for egg, chick and adult turkey. The market intermediaries of turkey farm carried out different marketing functions e.g. buying and selling, pricing, transportation, sorting, distribution and market information. The average net return and benefit-cost ratio was BDT 127838.04 and 1.38, respectively for 50 turkeys per year. In the study, turkey rearing found some comparative benefit over chicken and ducks e.g. higher weight gain, forage eater, lower diseases rate and suitability for the country. The main problem of turkey rearing identified as market instability, lack of quality turkey feed, higher feed price, lack of proper marketing facility and training on turkey farming. In conclusion, the small-scale turkey farming could be a viable source of income for the rural people of Bangladesh after taking some remedial steps by the Government of Bangladesh for the aforesaid hindrances faced by the turkey farmers

Hybrid Generators-based AC Microgrid Performance Assessment in Island Mode

Achieving an accurate steady-state averaged active power sharing between parallel inverters in islanded AC microgrids could be realized by a traditional droop control. For identical inverters having the same droop gains, it is assumed that the transient average power responses will be similar, and no circulating current will flow between the units. However, different line impedances could influence the instantaneous power significantly and thus circulating power flows among the inverters particularly during sudden disturbances such as load changes. This power, if absorbed by an inverter, will lead the DC link voltage to rise abruptly and trip the inverter, thus, degrading the performance of the whole microgrid. The problem becomes worse when hybrid generators are serving as unidirectional power source. This paper assesses the performance of hybrid generators within an islanded microgrid against the mismatch in line impedances. Two schemes to stabilize the microgrid are proposed. In addition, a participation factor analysis is developed to select the most effective controller scheme to bound the DC link voltage and minimize the circulating power. Simulation and experimental results are presented to verify the analysis and the capability of the proposed controller

JMJD5 is a human arginyl C-3 hydroxylase.

Oxygenase-catalysed post-translational modifications of basic protein residues, including lysyl hydroxylations and Nε-methyl lysyl demethylations, have important cellular roles. Jumonji-C (JmjC) domain-containing protein 5 (JMJD5), which genetic studies reveal is essential in animal development, is reported as a histone Nε-methyl lysine demethylase (KDM). Here we report how extensive screening with peptides based on JMJD5 interacting proteins led to the finding that JMJD5 catalyses stereoselective C-3 hydroxylation of arginine residues in sequences from human regulator of chromosome condensation domain-containing protein 1 (RCCD1) and ribosomal protein S6 (RPS6). High-resolution crystallographic analyses reveal overall fold, active site and substrate binding/product release features supporting the assignment of JMJD5 as an arginine hydroxylase rather than a KDM. The results will be useful in the development of selective oxygenase inhibitors for the treatment of cancer and genetic diseases

Understanding the information landscape in agricultural communities in rural Bangladesh

Knowledge sharing in rural agricultural communities is vital to the success of farmers and sustaining high yields. A range of actors in the knowledge landscape participate in knowledge sharing, and with this, a variety of complexities are introduced. In this paper, we report on a set of field visits, interviews and focus groups in various settings to understand this complex nature of the knowledge landscape. Our study was set within multiple locations within 20 miles North-East of Dhaka, the capital city of Bangladesh. Our findings highlight the high level of interconnectedness of different actors in the agricultural communities and the complexities involved in establishing trust of information. We report on the importance of fostering successful relationships within the communities and the growing strains of climate change

The effect of umbilical cord cleansing with chlorhexidine on omphalitis and neonatal mortality in community settings in developing countries: a meta-analysis.

BACKGROUND: There is an increased risk of serious neonatal infection arising through exposure of the umbilical cord to invasive pathogen in home and facility births where hygienic practices are difficult to achieve. The World Health Organization currently recommends 'dry cord care' because of insufficient data in favor of or against topical application of an antiseptic. The primary objective of this meta-analysis is to evaluate the effects of application of chlorhexidine (CHX) to the umbilical cord to children born in low income countries on cord infection (omphalitis) and neonatal mortality. Standardized guidelines of Child Health Epidemiology Reference Group (CHERG) were followed to generate estimates of effectiveness of topical chlorhexidine application to umbilical cord for prevention of sepsis specific mortality, for inclusion in the Lives Saved Tool (LiST). METHODS: Systematic review and meta-analysis. Data sources included Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, PubMed, CINHAL and WHO international clinical trials registry. Only randomized trials were included. Studies of children in hospital settings were excluded. The comparison group received no application to the umbilical cord (dry cord care), no intervention, or a non-CHX intervention. Primary outcomes were omphalitis and all-cause neonatal mortality. RESULTS: There were three cluster-randomised community trials (total participants 54,624) conducted in Nepal, Bangladesh and Pakistan that assessed impact of CHX application to the newborn umbilical cord for prevention of cord infection and mortality. Application of any CHX to the umbilical cord of the newborn led to a 23% reduction in all-cause neonatal mortality in the intervention group compared to control [RR 0.77, 95 % CI 0.63, 0.94; random effects model, I2=50 %]. The reduction in omphalitis ranged from 27 % to 56 % compared to control group depending on severity of infection. Based on CHERG rules, effect size for all-cause mortality was used for inclusion to LiST model as a proxy for sepsis specific mortality. CONCLUSIONS: Application of CHX to newborn umbilical cord can significantly reduce incidence of umbilical cord infection and all-cause mortality among home births in community settings. This inexpensive and simple intervention can save a significant number of newborn lives in developing countries

Impact of 4.0% chlorhexidine cleansing of the umbilical cord on mortality and omphalitis among newborns of Sylhet, Bangladesh: design of a community-based cluster randomized trial

<p>Abstract</p> <p>Background</p> <p>The World Health Organization recommends dry cord care for newborns but this recommendation may not be optimal in low resource settings where most births take place in an unclean environment and infections account for up to half of neonatal deaths. A previous trial in Nepal indicated that umbilical cord cleansing with 4.0% chlorhexidine could substantially reduce mortality and omphalitis risk, but policy changes await additional community-based data.</p> <p>Methods</p> <p>The Projahnmo Chlorhexidine study was a three-year, cluster-randomized, community-based trial to assess the impact of three cord care regimens on neonatal mortality and omphalitis. Women were recruited mid-pregnancy, received a basic package of maternal and neonatal health promotion messages, and were followed to pregnancy outcome. Newborns were visited at home by local village-based workers whose areas were randomized to either 1) single- or 2) 7-day cord cleansing with 4.0% chlorhexidine, or 3) promotion of dry cord care as recommended by WHO. All mothers received basic messages regarding hand-washing, clean cord cutting, and avoidance of harmful home-base applications to the cord. Death within 28 days and omphalitis were the primary outcomes; these were monitored directly through home visits by community health workers on days 1, 3, 6, 9, 15, and 28 after birth.</p> <p>Discussion</p> <p>Due to report in early 2010, the Projahnmo Chlorhexidine Study examines the impact of multiple or single chlorhexidine cleansing of the cord on neonatal mortality and omphalitis among newborns of rural Sylhet District, Bangladesh. The results of this trial will be interpreted in conjunction with a similarly designed trial previously conducted in Nepal, and will have implications for policy guidelines for optimal cord care of newborns in low resource settings in Asia.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov (NCT00434408)</p

Ribosomal oxygenases are structurally conserved from prokaryotes to humans

2-Oxoglutarate (2OG)-dependent oxygenases have important roles in the regulation of gene expression via demethylation of N-methylated chromatin components1,2 and in the hydroxylation of transcription factors3 and splicing factor proteins4. Recently, 2OG-dependent oxygenases that catalyse hydroxylation of transfer RNA5,6,7 and ribosomal proteins8 have been shown to be important in translation relating to cellular growth, TH17-cell differentiation and translational accuracy9,10,11,12. The finding that ribosomal oxygenases (ROXs) occur in organisms ranging from prokaryotes to humans8 raises questions as to their structural and evolutionary relationships. In Escherichia coli, YcfD catalyses arginine hydroxylation in the ribosomal protein L16; in humans, MYC-induced nuclear antigen (MINA53; also known as MINA) and nucleolar protein 66 (NO66) catalyse histidine hydroxylation in the ribosomal proteins RPL27A and RPL8, respectively. The functional assignments of ROXs open therapeutic possibilities via either ROX inhibition or targeting of differentially modified ribosomes. Despite differences in the residue and protein selectivities of prokaryotic and eukaryotic ROXs, comparison of the crystal structures of E. coli YcfD and Rhodothermus marinus YcfD with those of human MINA53 and NO66 reveals highly conserved folds and novel dimerization modes defining a new structural subfamily of 2OG-dependent oxygenases. ROX structures with and without their substrates support their functional assignments as hydroxylases but not demethylases, and reveal how the subfamily has evolved to catalyse the hydroxylation of different residue side chains of ribosomal proteins. Comparison of ROX crystal structures with those of other JmjC-domain-containing hydroxylases, including the hypoxia-inducible factor asparaginyl hydroxylase FIH and histone Nε-methyl lysine demethylases, identifies branch points in 2OG-dependent oxygenase evolution and distinguishes between JmjC-containing hydroxylases and demethylases catalysing modifications of translational and transcriptional machinery. The structures reveal that new protein hydroxylation activities can evolve by changing the coordination position from which the iron-bound substrate-oxidizing species reacts. This coordination flexibility has probably contributed to the evolution of the wide range of reactions catalysed by oxygenases