15 research outputs found
Role of fish in enhancing ricefield ecology and in integrated pest management: summary report
Summary report of the Third Asian Regional Rice-Fish Farming Research and Development Workshop, Indonesia, 1993. Includes sessions on ricefield ecology and fish; integrated pest management (IPM); research methodology; and IPM adoption.Rice-fish aquaculture, Culture effects, Pest control, Integrated farming
Thermal expansion and pressure effect in MnWO4
MnWO4 has attracted attention because of its ferroelectric property induced
by frustrated helical spin order. Strong spin-lattice interaction is necessary
to explain ferroelectricity associated with this type of magnetic order.We have
conducted thermal expansion measurements along the a, b, c axes revealing the
existence of strong anisotropic lattice anomalies at T1=7.8 K, the temperature
of the magnetic lock-in transition into a commensurate low-temperature
(reentrant paraelectric) phase. The effect of hydrostatic pressure up to 1.8
GPa on the FE phase is investigated by measuring the dielectric constant and
the FE polarization. The low- temperature commensurate and paraelectric phase
is stabilized and the stability range of the ferroelectric phase is diminished
under pressure.Comment: 2 pages, 3 figures. SCES conference proceedings, houston, TX, 2007.
to be published in Physica
Rice-fish research and development in Asia
Joint proceedings of two international workshops on rice-fish farming systems research and development û one held in Ubon, Thailand, on 23-27 October 1988; and the other on 23-27 October 1989 in Nueva Ecija, Philippines; gathering country overviews, production systems, economic and biological interactions, research and extension programs, and on-station and on-farm research activities from Bangladesh, China, India, Indonesia, Korea, Malaysia, the Philippines, Thailand and Vietnam.Rice-fish culture, Integrated farming, Conferences, Asia,
Microscopic mechanisms of spin-dependent electric polarization in 3d oxides
We present a short critical overview of different microscopic models for
nonrelativistic and relativistic magnetoelectric coupling including the
so-called "spin current scenario", ab-initio calculations, and several recent
microscopic approaches to a spin-dependent electric polarization in 3d oxides.Comment: 8 pages, 3 figure
Double-exchange model study of multiferroic MnO perovskites
In this proceeding, recent theoretical investigations by the authors on the
multiferroic MnO perovskites are briefly reviewed at first. Using the
double-exchange model, the realistic spiral spin order in undoped manganites
such as TbMnO and DyMnO is well reproduced by incorporating a weak
next-nearest neighbor superexchange ( of nearest neighbor
superexchange) and moderate Jahn-Teller distortion. The phase transitions from
the A-type antiferromagnet (as in LaMnO), to the spiral phase (as in
TbMnO), and finally to the E-type antiferromagnet (as in HoMnO), with
decreasing size of the ions, were also explained. Moreover, new results of
phase diagram of the three-dimensional lattice are also included. The
ferromagnetic tendency recently discovered in the LaMnO and TbMnO thin
films is explained by considering the substrate stress. Finally, the
relationship between our double-exchange model and a previously used
-- model is further discussed from the perspective of spin wave
excitations.Comment: 6 pages, 3 figures; Proceeding of the Workshop on Magnetoelectric
Interaction Phenomena in Crystals (MEIPIC-6); To be appeared in European
Physical Journal
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
Trophic models of aquatic ecosystems
Le riz et le poisson constituent la base du régime alimentaire des populations asiatiques. Des travaux récents indiquent que l'intégration de la pisciculture dans les rizières (une technologie actuellement trés peu répandue) peut permettre d'augmenter les rendements en riz de 15% et produire jusqu'à 500 kg de poisson par hectare et par cycle cultural. Cette pratique devrait égalemnt permettre de réduire les applications d'insecticides et de remplacer une partie des apports d'engrais azotés par des sous-produits agricoles destinés à l'alimentation du poisson. Afin d'améliorer les connaissances sur le cycle de l'azote en présence et en absence de pisciculture dans les rizières, nous avons utilisé le programme ECOPATH II pour construire des modèles des deux écosystèmes. En raison du manque de données quantitatives pour un certain nombre de composants de l'écosystème rizière, ces modèles sont préliminaires. Ils permettent toutefois de déterminer les indicateurs importants pour l'étude de l'écosystème. Des modèles ultérieurs devraient permettre de préciser les conditions optimale pour la gestion de la pisciculture en rizière. (Résumé d'auteur