530 research outputs found
Quantum Curves and Asymptotic Hodge Theory
This dissertation explores a 2015 conjecture of Codesido-Grassi-Marino in topologicalstring theory that relates the enumerative invariants of toric CY 3-folds to the spectra of operators attached to their mirror curves. In the maximally supersymmetric case, our first theorem relates zeroes of the higher normal function associated to an integral K2-class on the mirror curve to the spectra of the operators for curves of genus one, and suggests a new link between analysis and arithmetic geometry. On the other hand in the ât Hooft limit, [KM, MZ] deduced from the [CGM] conjecture that the limiting values of the local mirror map at the maximal conifold point are given by values of the Bloch-Wigner dilogarithm at algebraic arguments. Our second theorem establishes these assertions by calculating regulator periods on the mirror curves attached to 3-term operators coming from triangles. As a consequence numerous series identities involving the Bloch-Wigner dilogarithm are demonstrated
Climate-driven differences in growth performance of cohabitant fir and birch in a subalpine forest in Dhorpatan Nepal
Himalayan Silver Fir (Abies spectabilis) and Himalayan Birch (Betula utilis) are tree species often found coexisting in sub-alpine forests of the Nepal Himalayas. To assess species-specific growth performances of these species, tree-ring samples were collected from the subalpine forest in the Dhorpatan Hunting Reserve, Nepal. Standard ring width chronologies of both species were correlated with climatic variables in both static and running windows. Differential and contrasting temporal responses of radial growth of these species to climate were found. Warmer and drier springs appeared to limit birch radial growth. Whereas radial growth of fir showed weakened climate sensitivity. Moving correlation analyses revealed divergent influences of spring climate on both fir and birch. Significant warming that occurred in the 1970s coincided with growth declines in birch and an increase in fir, as indicated by basal area increment. In summary, recent warming has been unfavorable for birch, and favorable to fir radial growth.publishedVersio
Low castes have poor access to visceral leishmaniasis treatment in Bihar, India
Objectivesâ Bihar, the poorest state in India, concentrates most of the visceral leishmaniasis (VL) cases in the country. A large proportion of the poor rural communities where VL is endemic are marginalized by their socio-economic status, intrinsically related to the caste system. In this study, we evaluated whether people from low socio-economic strata had difficulties accessing VL treatment in Bihar. As a secondary outcome, we evaluated whether people delaying their VL treatment had poorer clinical indicators at admission. Methodsâ Data on 2187 patients with VL treated by MĂ©decins Sans FrontiĂšres (MSF) in Vaishali district from July 2007 to December 2008 were analysed. Patients who reported having onset of symptoms â„8âweeks before admission were defined as 'late presenters'. Logistic regression models were used to evaluate whether low castes had higher risk to be 'late presenters' compared to the rest of castes and whether 'late presenters' had poorer indicators at admission (i.e. haemoglobin level, spleen size). Resultsâ After adjusting for age, gender and distance to VL treatment facility, Mushars (the lowest caste in Bihar) had twice the odds to be 'late presenters' compared to the rest of castes (OR 2.05, 95% CI: 1.24-2.38). Subjects that had VL symptoms for â„8âweeks had a larger spleen and lower haemoglobin level than those that were treated earlier. Conclusionâ Low castes have poor access to VL treatment in Bihar, and late presenters have poorer clinical indicators at admission. These findings have implications at individual and community levels and should stimulate targeted VL control programmes to ensure that marginalized communities in Bihar are properly treated
New and improved method of bamboo cultivation in semi arid areas of Indian Thar desert
Bamboo (Dendrocalamus strictus Roxb.) is widely utilized in construction, pulp and paper, furniture, food and medicine, fuel and handicrafts for a long time. Due to its wider application, a field experiment was carried out to check its cultivation requirements besides its success rate in semi arid area of Indian Thar desert. In the present work, Guggul (Commiphora wightii Arnott.) which is a resident plant of Thar desert has been proved as a potential intercrop in bamboo cultivation. Improved growth was observed in bamboo with plant height (8.92 to 20.74 feet), number of culms (19 to 38), culm diameter (2.2 to 4.3 cm) during intercropping of guggul. Among different methods of irrigation, highest growth was recorded in drip irrigated plants where 50% recommended N:P:K and organic manure were given in combination followed by N:P:K sole. This study indicates that Guggul may play a role in microclimate development in the bamboo cultivation. This is the first report on successful bamboo cultivation in semi arid area of desert using an intercrop.Key words: Dendrocalamus, soil enzymes, fertilization, guggul, nitrogen
Post COVID-19 multisystem inflammatory syndrome in adults: a new clinical challenge
The spectrum of novel coronavirus disease (COVID-19) continues to evolve since its outbreak in November 2019. Although COVID-19 most commonly causes substantial respiratory pathology, it can also result in several extra pulmonary manifestations. Association between COVID-19 disease and a multisystem inflammatory syndrome in children (MIS-C) and adolescents has now been well defined. However, case reports describing a similar phenomenon in adults are sparse. We presented a case of 42 year old male who presented 3 weeks after initial COVID-19 infection with acute ST elevation myocardial infarction, splenic artery thrombosis, generalized anasarca, with hepatic and renal dysfunction, but minimal respiratory symptoms. He had a turbulent hospital course. However timely suspicion of presence of multisystem inflammatory syndrome in adult (MIS-A) and use of hemoadsorption filters helped to save his life
Synthesis and in vitro evaluation of hydrazinyl phthalazines against malaria parasite, Plasmodium falciparum.
In this report, we describe the synthesis of 1-(Phthalazin-4-yl)-hydrazine using bronsted acidic ionic liquids and demonstrate their ability to inhibit asexual stage development of human malaria parasite, Plasmodium falciparum. Through computational studies, we short-listed chemical scaffolds with potential binding affinity to an essential parasite protein, dihydroorotate dehydrogenase (DHODH). Further, these compounds were synthesized in the lab and tested against P. falciparum. Several compounds from our library showed inhibitory activity at low micro-molar concentrations with minimal cytotoxic effects. These results indicate the potential of hydralazine derivatives as reference scaffolds to develop novel antimalarials
tRNA epitranscriptomics and biased codon are linked to proteome expression in
Among components of the translational machinery, ribonucleoside modifications on tRNAs are emerging as critical regulators of cell physiology and stress response. Here, we demonstrate highly coordinated behavior of the repertoire of tRNA modifications of Plasmodium falciparum throughout the intra-erythrocytic developmental cycle (IDC). We observed both a synchronized increase in 22 of 28 modifications from ring to trophozoite stage, consistent with tRNA maturation during translational up-regulation, and asynchronous changes in six modifications. Quantitative analysis of ~2,100 proteins across the IDC revealed that up- and down-regulated proteins in late but not early stages have a marked codon bias that directly correlates with parallel changes in tRNA modifications and enhanced translational efficiency. We thus propose a model in which tRNA modifications modulate the abundance of stage-specific proteins by enhancing translation efficiency of codon-biased transcripts for critical genes. These findings reveal novel epitranscriptomic and translational control mechanisms in the development and pathogenesis of Plasmodium parasites.Singapore. National Research FoundationSingapore-MIT Alliance (Graduate Fellowship
Salicylic acid enhances resistance in cowpea against Meloidogyne incognita
Salicylic acid (10 mM) sprayed on cowpea leaves inoculated with Meloidogyne incognita reduced nematode
infection and promoted plant growth. Salicylic acid did not kill nematodes in an in vitro test and induced expression
and accumulation of pathogenesis related-1 protein in the leaves of sprayed plants. The presence of Tween-20
enhanced the effect of salicylic acid on the accumulation of pathogenesis related-1 protein
Beneficial Effects of Temperate Forage Legumes that Contain Condensed Tannins
The two temperate forage legumes containing condensed tannins (CT) that promote ruminant production are birdsfoot trefoil (Lotus corniculatus L.; BFT) and sainfoin (Onobrychis viciifolia Scop.; SF). Both are well-adapted to the cool-temperate climate and alkaline soils of the Mountain West USA. Condensed tannins comprise a diverse family of bioactive chemicals with multiple beneficial functions for ruminants, including suppression of internal parasites and enteric methane. Birdsfoot trefoil contains 10 to 40 g·CT·kgâ1 dry matter (DM), while SF contains 30 to 80 g·CT·kgâ1 DM. Our studies have focused on these two plant species and have demonstrated consistently elevated rates of gain for beef calves grazing both BFT and SF. Novel results from our BFT research include carcass dressing percentages and consumer sensory evaluations equivalent to feedlot-finished steers and significantly greater than grass-finished steers, but with omega-3 fatty acid concentrations equal to grass-finished beef. We have further demonstrated that ruminants fed BFT or SF will consume more endophyte-infected tall fescue (Schedonorus arundinaceus (Schreb.) Dumort.) forage or seed than ruminants fed a non-CT forage legume. There is great potential value for sustainable livestock production in the use of highly digestible, nitrogen-fixing legumes containing tannins demonstrated to improve ruminant productivity
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