Labour Demand and Labour-saving Options: A Case of Groundnut Crop in India

Groundnut is a labour-intensive crop, especially for operations like sowing, weeding, harvesting, and drying. But, of-late, due to timely unavailability of labour, many farmers are not able to exercise timely operations resulting in low yield realization. The present study conducted in two major groundnut-growing states, viz. Gujarat and Andhra Pradesh, has revealed that farmers employ more human labour in weeding and harvesting operations in groundnut than in other operations. The practise of manual decortication and stripping is followed by a larger number of farmers in Andhra Pradesh than in Gujarat, indicating less mechanization in the former. For weeding, though, the human labour-use in weedicide + bullock intercultivation + hand weeding technique is almost half of that of the bullock inter-cultivation + hand weeding, only 13 per cent of the farmers practise this labour-saving technique and hence this method should be disseminated in both the regions to reduce human-labour demand. In Andhra Pradesh, for all the operations in groundnut cultivation except harvesting, the cost as well as labour-use has been reduced substantially due to use of partial/complete mechanization methods. Hence, the necessary infrastructure (labour-saving machineries) should be created at the village or block level to reduce the human-labour demand.Labour demand, Groundnut cultivation, Labour-saving techniques, Agricultural and Food Policy, J23, J21,

Metal complexes used as anti-inflammatory agents: Synthesis, characterization and anti-inflammatory action of VO(II)-complexes

AbstractThe anti-inflammatory activity of the vanadium complexes has been studied using the carrageenan induced hind paw oedema method in albino rats (Wister strain). The coordination complexes of VO (II) with the Schiff base derived from 4-aminoacetophenone, 1-acetonaphthone and 4-methoxybenzaldehyde with 2-imino 4-thiobiuret; 3-acetoxypyridine with 2-amino 4-benzathiazol and 4-chloro aniline with salicylaldehyde have been synthesized and characterized by micro analytical data, FT-IR, electronic spectra and FAB-mass spectral studies. The Schiff base ligands behave as bidentated. The stoichiometry of the complexes is in 1:2 and 1:1 (M:L) ratio. The oxovanadium complexes in general show maximum inhibition percentage at about 1h. After 1h it goes on reducing and reaches a minimum at about 5h. Complex-3 (91.17%) and Complex-5 (85.30%) are most potent in in vivo experiment and exhibited promising anti-inflammatory activity in 0.5h

Rice allelopathy in weed management : an integrated approach

The intensive use of pesticides with low biodegradability and high persistence in soil, surface and ground waters, represents a considerable environmental risk, especially under high weed pressure conditions. Furthermore, the number of herbicide-resistant weeds is increasing. Against this background, the investigation of alternative weed control strategies has taken on considerable importance. Among these, allelopathy as a negative effect of one plant on another due to the direct or indirect (including microorganisms) release of chemicals in the environment can be a useful tool for the integrated management of weeds in agroecosystems. In particular, the paddies have been considered in this work by reviewing the data both on rice allelopathy and rice weed agronomic control methods developed to improve the crop yield

Antibacterial potential of Saussurea obvallata petroleum ether extract: A spiritually revered medicinal plant

Uttarakhand Himalayan region holds Asteraceae or Compositae as the largest family of flowering, medicinal and aromatic plants. Species belonging to this family rises from low altitude to the alpine region. Among Asteraceae, Saussurea obvallata (DC.) Edgew. is widely used in several indigenous systems of medicine. Flowers, leaves and rhizomes of S. obvallata are used for several traditional, religious, therapeutic and ornamental purposes. Aim of this study was to determine the chemical composition and antibacterial efficacy of petroleum ether extract (PEE) of S. obvallata. Gas chromatography-mass spectrometry (GC-MS) analysis was used for identifying phytochemicals present in the plant extract. Furthermore, the PEE was assessed for in-vitro antibacterial activity against selected Gram positive and negative strains. Structure of squalene and \u3b1-linolenic acid methyl ester were identified in PEE by GC-MS analysis, by comparing the results obtained with NIST library and literature reports. PEE exhibited significant activity against Staphylococcus aureus, Escherichia coli, Bacillus cereus, Bacillus subtilis with IC50 value of 87.2 \ub1 1.6, 98.4 \ub1 1.1 and 90.2 \ub1 1.8 \u3bcg/ml, respectively. These results showed that squalene and a-linolenic acid derivative identified in S. obvallata may be responsible for the observed antibacterial activity. To the best of our knowledge, this is the first report focused on the chemical composition and antibacterial activity of S. obvallata

Magnetic Phases of Electron-Doped Manganites

We study the anisotropic magnetic structures exhibited by electron-doped manganites using a model which incorporates the double-exchange between orbital ly degenerate $e_{g}$ electrons and the super-exchange between $t_{2g}$ electrons with realistic values of the Hund's coupling($J_H$), the super-exchange coupling($J_{AF}$), and the bandwidth($W$). We look at the relative stabilities of the G, C and A type antiferromagnetic ph ases. In particular we find that the G-phase is stable for low electron doping as seen in experiments. We find good agreement with the experimentally observed magnetic phase diagrams of electron-doped manganites ($x > 0.5$) such as Nd$_{1-x}$Sr$_{x}$MnO$_{3}$, Pr$_{1-x}$Sr$_{x}$MnO$_{3}$, and Sm$_{1-x}$Ca$_{x}$MnO$_{3}$. We can also explain the experimentally observed orbital structures of the C a nd A phases. We also extend our calculation for electron-doped bilayer manganites of the form R$_{2-2x}$A$_{1+2x}$Mn$_2$O$_7$ and predict that the C-phase will be absent in t hese systems due to their reduced dimensionality.Comment: 7 .ps files included. To appear in Phys. Rev. B (Feb 2001

Stability of the monoclinic phase in the ferroelectric perovskite PbZr(1-x)TixO3

Recent structural studies of ferroelectric PbZr(1-x)TixO3 (PZT) with x= 0.48, have revealed a new monoclinic phase in the vicinity of the morphotropic phase boundary (MPB), previously regarded as the the boundary separating the rhombohedral and tetragonal regions of the PZT phase diagram. In the present paper, the stability region of all three phases has been established from high resolution synchrotron x-ray powder diffraction measurements on a series of highly homogeneous samples with 0.42 <=x<= 0.52. At 20K the monoclinic phase is stable in the range 0.46 <=x<= 0.51, and this range narrows as the temperature is increased. A first-order phase transition from tetragonal to rhombohedral symmetry is observed only for x= 0.45. The MPB, therefore, corresponds not to the tetragonal-rhombohedral phase boundary, but instead to the boundary between the tetragonal and monoclinic phases for 0.46 <=x<= 0.51. This result provides important insight into the close relationship between the monoclinic phase and the striking piezoelectric properties of PZT; in particular, investigations of poled samples have shown that the monoclinic distortion is the origin of the unusually high piezoelectric response of PZT.Comment: REVTeX file, 7 figures embedde

First order transition and phase separation in pyrochlores with colossal-magnetoresistance

Tl$_{2}$Mn$_{2}$O$_{7}$ pyrochlores present colossal magnetoresistance (CMR) around the long range ferromagnetic ordering temperature (T$_{C}$). The character of this magnetic phase transition has been determined to be first order, by purely magnetic methods, in contrast to the second order character previously reported by Zhao et al. (Phys. Rev. Lett. 83, 219 (1999)). The highest CMR effect, as in Tl$_{1.8}$Cd$_{0.2}$Mn$_{2}$O$_{7}$, corresponds to a stronger first order character. This character implies a second type of magnetic interaction, besides the direct superexchange between the Mn$^{4+}$ ions, as well as a phase coexistence. A model is proposed, with a complete Hamiltonian (including superexchange and an indirect interaction), which reproduce the observed phenomenology.Comment: 6 pages. Figures include

Origin and pressure dependence of ferromagnetism in A2Mn2O7 pyrochlores (A=Y, In, Lu, and Tl)

Non-conventional mechanisms have been recently invoked in order to explain the ferromagnetic ground state of A2Mn2O7 pyrochlores (A=Y, In, Lu and Tl) and the puzzling decrease of their Curie temperatures with applied pressure. Here we show, using a perturbation expansion in the Mn-O hopping term, that both features can be understood within the superexhange model, provided that the intra-atomic oxygen interactions are properly taken into account. An additional coupling between the Mn ions mediated by the In(5s)/Tl(6s) bands yields the higher Tc's of these two compounds, this mechamism enhancing their ferromagnetism for higher pressures.Comment: 7 pages and 2 figures submitted to Phys. Rev. B, missing text adde

Satyrium nepalense, a high altitude medicinal orchid of Indian Himalayan region : chemical profile and biological activities of tuber extracts

The present study investigated antioxidant and antibacterial activities of 5 different extracts and derived fractions from the S. nepalense tubers. Identification of the most active fractions, their phytochemical characterization, total phenolic and flavonoid contents, and biological activities were also evaluated. Petroleum ether, chloroform, ethyl acetate, methanol, water extracts and methanol fractions were screened for their antibacterial activity at 10, 50 and 100 mg/mL doses against ten Gram-negative and Gram-positive bacterial strains by disc diffusion method. Their total antioxidant activity was measured by DPPH and ABTS assays. Identification of the main compounds was performed by LC-MS/MS. Methanol extract exhibited the highest antioxidant (IC50= 30.79 \u3bcg/mL and 24.53 \u3bcg/mL for DPPH and ABTS, respectively) and antibacterial (MIC 71.5 to &gt; 100 \u3bcg/mL) activities in comparison with the other extracts. Levels of phenolics and flavonoids were also the highest in the same extract, i.e. 19.2 mg GAE/g and 11.20 mg QE/g, respectively. Phytochemical investigation of the active fractions of the methanol extract led to the isolation of gallic acid (19.04 mg/g) and quercetin (23.4 mg/g). Therefore, methanol extract showed an interesting potential for both antioxidant and antibacterial activities, thus deserving attention for future applications in the fields of medicinal plants and food supplements

A spatially-VSL gravity model with 1-PN limit of GRT

A scalar gravity model is developed according the 'geometric conventionalist' approach introduced by Poincare (Einstein 1921, Poincare 1905, Reichenbach 1957, Gruenbaum1973). In principle this approach allows an alternative interpretation and formulation of General Relativity Theory (GRT), with distinct i) physical congruence standard, and ii) gravitation dynamics according Hamilton-Lagrange mechanics, while iii) retaining empirical indistinguishability with GRT. In this scalar model the congruence standards have been expressed as gravitationally modified Lorentz Transformations (Broekaert 2002). The first type of these transformations relate quantities observed by gravitationally 'affected' (natural geometry) and 'unaffected' (coordinate geometry) observers and explicitly reveal a spatially variable speed of light (VSL). The second type shunts the unaffected perspective and relates affected observers, recovering i) the invariance of the locally observed velocity of light, and ii) the local Minkowski metric (Broekaert 2003). In the case of a static gravitation field the model retrieves the phenomenology implied by the Schwarzschild metric. The case with proper source kinematics is now described by introduction of a 'sweep velocity' field w: The model then provides a hamiltonian description for particles and photons in full accordance with the first Post-Newtonian approximation of GRT (Weinberg 1972, Will 1993).Comment: v1: 11 pages, GR17 conf. paper, Dublin 2004, v2: WEP issue solved, section on acceleration transformation added, text improved, more references, same results, v3: typos removed, footnotes, added and references updated, v4: appendix added, improved tex