Permutability graphs of subgroups of some finite non-abelian groups

In this paper, we study the structure of the permutability graphs of subgroups, and the permutability graphs of non-normal subgroups of the following groups: the dihedral groups $D_n$, the generalized quaternion groups $Q_n$, the quasi-dihedral groups $QD_{2^n}$ and the modular groups $M_{p^n}$. Further, we investigate the number of edges, degrees of the vertices, independence number, dominating number, clique number, chromatic number, weakly perfectness, Eulerianness, Hamiltonicity of these graphs.Comment: 35 pages, 1 figur

Health Risk Perceptions, Awareness and Handling Behaviour of Pesticides by Farm Workers

The level of awareness regarding pesticide use/ handling has been reported in the farms of Kerala and the same has been compared with the adoption pattern and experiences of health risk episodes, in a society with high level of literacy. The understanding on various aspects of pesticide-use has revealed better awareness in certain aspects and poor understanding in certain others. The workers have not been given adequate training to understand the toxicity level by looking at the colour code on the packet, though they have been found aware about the different options available in the market. Often their perceptions of toxicity level of chemicals they handle are not in conformity with the actual situation; they have been found handling toxic chemicals considering them to be safe ones. Despite a high literacy level, most of them do not care to read the instructions and follow them. The study has found that a majority of the respondents are of satisfactory health status by the body mass index values. The short-term health risk upon occupational exposure has been reported very common; its frequency increases as one gets more years of experience in the work. It has been attributed to their inadequate understanding of the toxicity levels, unscientific handling practices and poor personal protective mechanism. The study has highlighted the need for targeted trainings to farm labourers besides farmers on the scientific management of pesticides and undertaking of massive awareness generation programmes.Agricultural and Food Policy,

Classification of finite groups with toroidal or projective-planar permutability graphs

Let $G$ be a group. The permutability graph of subgroups of $G$, denoted by $\Gamma(G)$, is a graph having all the proper subgroups of $G$ as its vertices, and two subgroups are adjacent in $\Gamma(G)$ if and only if they permute. In this paper, we classify the finite groups whose permutability graphs are toroidal or projective-planar. In addition, we classify the finite groups whose permutability graph does not contain one of $K_{3,3}$, $K_{1,5}$, $C_6$, $P_5$, or $P_6$ as a subgraph.Comment: 30 pages, 8 figure

Is Irrigation Water only Used for Irrigation? An Enquiry into the Alternative Uses and an Attempt on Valuation

Irrigation sector investments in Kerala have been mounting since Independence, but the financial performance of these investments has been far from satisfactory. In an era of growing divergence in water supply and demand, the emergence of water markets is imminent. This calls for a realistic pricing strategy for water use, whether in agriculture or other sectors. The canal water though targeted at the agriculture sector, is often put to non-irrigation uses. This paper has discussed a method to quantify the non-irrigation uses of canal water and has assessed the value of the same, based on a sample study in Peechi Irrigation Command Area in Thrissur district of Kerala, India . The value has been assessed for the water used directly for irrigation from the canal system, water used through the recharge facility from the canal and non-irrigation uses (domestic).Agricultural and Food Policy,