A Diagnosis of Biophysical and Socio-Economic Factors Influencing Farmers’ Choice to Adopt Organic or Conventional Farming Systems for Cotton Production

Organic agriculture is one of the most widely known alternative production systems advocated for its benefits to soil, environment, health and economic well-being of farming communities. Rapid increase in the market demand for organic products presents a remarkable opportunity for expansion of organic agriculture. A thorough understanding of the context specific motivations of farmers for adoption of organic farming systems is important so that appropriate policy measures are put in place. With an aim of understanding the social and biophysical motivations of organic and conventional cotton farmers for following their respective farming practices, a detailed farm survey was conducted in Nimar valley of Madhya Pradesh state in central India. The study area was chosen for being an important region for cotton production, where established organic and conventional farms operate under comparable circumstances. We found considerable variation among organic and conventional farmers for their social and biophysical motivations. Organic farmers were motivated by the sustainability of cotton production and growing safer food without pesticides, whereas conventional farmers were sensitive about their reputation in community. Organic farmers with larger holdings were more concerned about closed nutrient cycles and reducing their dependence on external inputs, whereas medium and small holding organic farmers were clearly motivated by the premium price of organic cotton. Higher productivity was the only important motivation for conventional farmers with larger land holdings. We also found considerable yield gaps among different farms, both under conventional and organic management, that need to be addressed through extension and training. Our findings suggest that research and policy measures need to be directed toward strengthening of extension services, local capacity building, enhancing availability of suitable inputs and market access for organic farmers

The high-pressure behavior of CaMoO4

We report a high-pressure study of tetragonal scheelite-type CaMoO4 up to 29 GPa. In order to characterize its high-pressure behavior, we have combined Raman and optical-absorption measurements with density-functional theory calculations. We have found evidence of a pressure-induced phase transition near 15 GPa. Experiments and calculations agree in assigning the high-pressure phase to a monoclinic fergusonite-type structure. The reported results are consistent with previous powder x-ray-diffraction experiments, but are in contradiction with the conclusions obtained from earlier Raman measurements, which support the existence of more than one phase transition in the pressure range covered by our studies. The observed scheelite-fergusonite transition induces significant changes in the electronic band gap and phonon spectrum of CaMoO4. We have determined the pressure evolution of the band gap for the low- and high-pressure phases as well as the frequencies and pressure dependences of the Raman-active and infrared-active modes. In addition, based upon calculations of the phonon dispersion of the scheelite phase, carried out at a pressure higher than the transition pressure, we propose a possible mechanism for the reported phase transition. Furthermore, from the calculations we determined the pressure dependence of the unit-cell parameters and atomic positions of the different phases and their room-temperature equations of state. These results are compared with previous experiments showing a very good agreement. Finally, information on bond compressibility is reported and correlated with the macroscopic compressibility of CaMoO4. The reported results are of interest for the many technological applications of this oxide.Comment: 36 pages, 10 figures, 8 table

High pressure studies on properties of FeGa3: role of on-site coulomb correlation

High pressure X-ray diffraction measurements have been carried out on the intermetallic semiconductor FeGa$_3$ and the equation of state for FeGa$_3$ has been determined. First principles based DFT calculations within the GGA approximation indicate that although the unit cell volume matches well with the experimentally obtained value at ambient pressure, it is significantly underestimated at high pressures and the difference between them increases as pressure increases. GGA + U calculations with increasing values of U$_{Fe(3d)}$ (on-site Coulomb repulsion between the Fe 3d electrons) at high pressures, correct this discrepancy. Further, the GGA+U calculations also show that along with U$_{Fe(3d)}$, the Fe 3d band width also increases with pressure and around a pressure of 4 GPa, a small density of states appear at the Fermi level. High pressure resistance measurements carried out on FeGa$_3$ also clearly show a signature of an electronic transition. Beyond the pressure of 19.7 GPa, the diffraction peaks reduce in intensity and are not observable beyond $\sim$ 26 GPa, leading to an amorphous state

Low temperature and high pressure Raman and x-ray studies of pyrochlore Tb2_2Ti2_2O7_7 : phonon anomalies and possible phase transition

We have carried out temperature and pressure-dependent Raman and x-ray measurements on single crystals of Tb$_2$Ti$_2$O$_7$. We attribute the observed anomalous temperature dependence of phonons to phonon-phonon anharmonic interactions. The quasiharmonic and anharmonic contributions to the temperature-dependent changes in phonon frequencies are estimated quantitatively using mode Gr\"{u}neisen parameters derived from pressure-dependent Raman experiments and bulk modulus from high pressure x-ray measurements. Further, our Raman and x-ray data suggest a subtle structural deformation of the pyrochlore lattice at $\sim$ 9 GPa. We discuss possible implications of our results on the spin-liquid behaviour of Tb$_2$Ti$_2$O$_7$.Comment: 10 figures, 26 pages. Appeared in Physical Review B, vol-79, pp-134112 (2009

What socially motivates farmers to grow organic cotton in central India?

India is the largest producer of ‘organic cotton’, as it contributes about three quarters (74%) to the global organic cotton production. The Nimar valley of Madhya Pradesh in central India is important region for organic cotton production. In general, cotton yields are low and variable in the Nimar valley and often do not reach the attainable levels on several farms of the region. With a steeply increasing demand for organic fibre, it is important to safeguard and increase the production of organic cotton in a sustainable manner. The precise understanding of social and biophysical motivations of different farmers for following their respective farming practices is of high importance for sustainable future of organic cotton in central India. The study of the facts related to adoption of organic cotton production systems in the Nimar valley is particularly valuable for policy makers, smallholder farmers and sourcing organizations

Rare Case of Buccal Exostosis in Edentulous Mandibular Body Region

Buccal exostoses are benign, broad-based surface masses of the facial aspect of the maxilla and less commonly, the mandible. It is believed that this is one way, bone responds to stresses applied to it. They begin to develop in the early adulthood and may slowly enlarge over the years. To the best of our knowledge, it is the second reported case of single buccal exostosis in mandibular molar region and first of its kind in edentulous mandible. The following paper presents a very rare and unique case of buccal-sided mandibular molar exostosis in an edentulous mandible of an old female and its surgical management

Realization of higher coordinated Er in high-pressure cotunnite phase of Er2_2Ti2_2O7_7

In this article we report the structural stability of Er$_2$Ti$_2$O$_7$ cubic pyrochlore with pressure using x-ray diffraction, Raman spectroscopy, photoluminescence, x-ray absorption and ab-initio calculations. Our studies establish a phase transformation in Er$_2$Ti$_2$O$_7$ from ambient cubic phase to high-pressure orthorhombic (cotunnite) phase, initiated at ~40 GPa. The transformation is sluggish and it does not complete even at the highest measured pressure in our study i.e. ~60.0 GPa. This is further supported by the first principle calculations which reveal that cotunnite phase is energetically more stable than the ambient phase above ~53 GPa. After complete release of pressure, the high-pressure cotunnite phase is retained while the fraction of untransformed pyrochlore phase becomes amorphous. Furthermore, the EXAFS data of the recovered sample at L3 edge of Er3+ ion show an increase in the coordination number of cations from eight at ambient to nine in the high-pressure phase. The mechanism of structural transformation is explained in terms of accumulation of cation antisite defects and subsequent disordering of cations and anions in their respective sublattice. The amorphization of the pyrochlore phase upon release is interpreted as the inability of accommodating the point defects at ambient conditions, which are formed in the pyrochlore lattice under compression

High pressure investigations on hydrous Magnesium Silicate-Phase A using first principles calculations, H---H repulsion and O-H bond compression

We have carried out first principles structural relaxation calculations on the hydrous magnesium silicate Phase A (Mg7Si2O8(OH)6) under high pressures. Our results show that phase A does not undergo any phase transition upto ~ 45 GPa. We find that nonbonded H---H distance reaches a limiting value of 1.85 Å at about 45 GPa. The H---H repulsive strain releasing mechanism in Phase A is found to be dramatically different from the hydrogen bond bending one that was proposed by Hofmeister et al1 for Phase B. It is based on the reduction of one of the O-H bond distances with compression

Ring chromosome 15 presenting as short stature, intellectual disability and café-au-lait spots

Ring Chromosome 15 results from loss of genetic material from both ends of chromosome 15 and joining of the ends to form ring. Only 50 cases are reported in literature with none from India. We report a case of 17 years old female approached us for short stature and low intelligence. On examination we noticed childish facial features, microcephaly and cafe-au-lait spots in significant number and size. Her karyotype result was 46xx r15. CONCLUSION: Ring chromosome 15 syndromes should be considered in a case having short stature with cafe-au-lait spots. Timely recognition and hereditary tendency counselling is required

Pressure-induced structural phase transitions in the chromium spinel LiInCr4O8 with breathing pyrochlore lattice

This study reports high-pressure structural and spectroscopic studies on polycrystalline cubic chromium spinel compound LiInCr4O8. According to pressure-dependent X-ray diffraction measurements, three structural phase transitions occur at ∼14 GPa, ∼19 GPa, and ∼36 GPa. The first high-pressure phase is indexed to the low-temperature tetragonal phase of the system which coexists with the ambient phase before transforming to the second high-pressure phase at ∼19 GPa. The pressure-dependent Raman and infrared spectroscopic measurements show a blue-shift of the phonon modes and the crystal field excitations and an increase in the bandgap under compression. During pressure release, the sample reverts to its ambient cubic phase, even after undergoing multiple structural transitions at high pressures. The experimental findings are compared to the results of first principles based structural and phonon calculations