The sustainability of Suranga irrigation in South Karnataka and northern Kerala, India

This paper reports the preliminary findings from an on-going research project that is exploring the resilience and sustainability of suranga irrigation technology found in the Western Ghats of south Karnataka and northern Kerala, India. The suranga are traditional adit water harvesting systems that tap ground waters. They have been constructed mainly by individual land owners to provide both drinking and irrigation water. This paper compares traditional suranga irrigation technology with that of more modern irrigation technology, first introduced during the green revolution, in terms of their impacts on livelihood strategies and water use efficiency. The paper also describes some of the recent adaptations made by farmers to suranga systems based on response to new crop growing opportunities and the availability of new conveyance and distribution technologies and materials. The paper concludes by exploring the resilience and sustainability of the traditional system from a catchment based perspective as the region faces the duel pressures of population increase and climate change.Submitted Versio

Defective linear and circular RNAs biogenesis in Huntington’s disease: CAG repeat expansion hijacks neuronal splicing

Alternative splicing (AS) appears to be altered in Huntington’s disease (HD), but its significance for early, pre-symptomatic disease stages has not been inspected. Here, taking advantage of Htt CAG knock-in mouse in vitro and in vivo models, we demonstrate a strong correlation between Htt CAG repeat length and increased aberrant linear AS, specifically affecting neural progenitors and, in vivo, the striatum prior to overt behavioral phenotypes stages. Remarkably, expanded Htt CAG repeats reflect on a previously neglected, global impairment of back-splicing, leading to decreased circular RNAs production in neural progenitors. Though the mechanisms of this dysregulation remain uncertain, our study unveils network of transcriptionally altered micro-RNAs and RNA-binding proteins (CELF, hnRNPS, PTBP, SRSF) which, in turn, might influence the AS machinery, primarily in neural cells. We suggest that this unbalanced expression of linear and circular RNAs might result in altered neural fitness, contributing to HD striatal vulnerability

Molecular basis of disease resistance in banana progenitor Musa Balbisiana against Xanthomonas Campestris pv. Musacearum

Open Access JournalBanana Xanthomonas wilt disease, caused by Xanthomonas campestris pv. musacearum (Xcm), is a major threat to banana production in east Africa. All cultivated varieties of banana are susceptible to Xcm and only the progenitor species Musa balbisiana was found to be resistant. The molecular basis of susceptibility and resistance of banana genotypes to Xcm is currently unknown. Transcriptome analysis of disease resistant genotype Musa balbisiana and highly susceptible banana cultivar Pisang Awak challenged with Xcm was performed to understand the disease response. The number of differentially expressed genes (DEGs) was higher in Musa balbisiana in comparison to Pisang Awak. Genes associated with response to biotic stress were up-regulated in Musa balbisiana. The DEGs were further mapped to the biotic stress pathways. Our results suggested activation of both PAMP-triggered basal defense and disease resistance (R) protein-mediated defense in Musa balbisiana as early response to Xcm infection. This study reports the first comparative transcriptome profile of the susceptible and resistant genotype of banana during early infection with Xcm and provide insights on the defense mechanism in Musa balbisiana, which can be used for genetic improvement of commonly cultivated banana varieties

Interacting RNA polymerase motors on DNA track: effects of traffic congestion and intrinsic noise on RNA synthesis

RNA polymerase (RNAP) is an enzyme that synthesizes a messenger RNA (mRNA) strand which is complementary to a single-stranded DNA template. From the perspective of physicists, an RNAP is a molecular motor that utilizes chemical energy input to move along the track formed by a DNA. In many circumstances, which are described in this paper, a large number of RNAPs move simultaneously along the same track; we refer to such collective movements of the RNAPs as RNAP traffic. Here we develop a theoretical model for RNAP traffic by incorporating the steric interactions between RNAPs as well as the mechano-chemical cycle of individual RNAPs during the elongation of the mRNA. By a combination of analytical and numerical techniques, we calculate the rates of mRNA synthesis and the average density profile of the RNAPs on the DNA track. We also introduce, and compute, two new measures of fluctuations in the synthesis of RNA. Analyzing these fluctuations, we show how the level of {\it intrinsic noise} in mRNA synthesis depends on the concentrations of the RNAPs as well as on those of some of the reactants and the products of the enzymatic reactions catalyzed by RNAP. We suggest appropriate experimental systems and techniques for testing our theoretical predictions.Comment: 13 pages, including 6 EPS figures; accepted for publication in Physical Review

Precedence-type Test based on Progressively Censored Samples

In this paper, we introduce precedence-type tests for testing the hypothesis that two distribution functions are equal, which is an extension of the precedence life-test rst proposed by Nelson (1963), when the two samples are progressively Type-II censored. The null distributions of the test statistics are derived. Critical values for some combination of sample sizes and censoring schemes for the proposed tests are presented. Then, we present the exact power functions under the Lehmann alternative, and compare the exact power as well as simulated power (under location-shift) of the proposed precedence test based on nonparametric estimates of CDF with other precedence-type tests. We then examine the power properties of the proposed test procedures through Monte Carlo simulations. Two examples are presented to illustrate all the test procedures discussed here. Finally, we make some concluding remarks.Precedence test; Product-limit estimator; Type-II progressive censoring; Life-testing; level of significance; power; Lehmann alternative; Monte Carlo simulations

Investigation of ion induced bending mechanism for nanostructures

Ion induced bending is a promising controlled technique for manipulating nanoscale structures. However, the underlying mechanism of the process is not well understood. In this letter, we report a detailed study of the bending mechanism of Si nanowires (NWs) under Ga+ irradiation. The microstructural changes in the NW due to ion beam irradiation are studied and molecular dynamics simulations are used to explore the ion–NW interaction processes. The simulation results are compared with the microstructural studies of the NW. The investigations inform a generic understanding of the bending process in crystalline materials, which we suggest to be feasible as a versatile manipulation and integration technique in nanotechnology

Nuclear magnetic resonance probes for the Kondo scenario for the 0.7 feature in semiconductor quantum point contact devices

We propose a probe based on nuclear relaxation and Knight shift measurements for the Kondo scenario for the "0.7 feature" in semiconductor quantum point contact (QPC) devices. We show that the presence of a bound electron in the QPC would lead to a much higher rate of nuclear relaxation compared to nuclear relaxation through exchange of spin with conduction electrons. Furthermore, we show that the temperature dependence of this nuclear relaxation is very non-monotonic as opposed to the linear-T relaxation from coupling with conduction electrons. We present a qualitative analysis for the additional relaxation due to nuclear spin diffusion (NSD) and study the extent to which NSD affects the range of validity of our method. The conclusion is that nuclear relaxation, in combination with Knight shift measurements, can be used to verify whether the 0.7 feature is indeed due to the presence of a bound electron in the QPC.Comment: Published version. Appears in a Special Section on the 0.7 Feature and Interactions in One-Dimensional Systems. 16 page

Potential Explosive Device on a Commuter Train: What drives train drivers to deviate from the security procedure?

Explosives pose a major threat to urban metro rail systems. Train drivers are therefore expected to regularly perform security procedures in response to reports of suspicious items on the train. This study was conducted to develop a multi-factorial account of deviation from one such security procedure by train drivers. By analysing data from focus group interviews with 30 train drivers, observation in a rail simulator, actual cab rides, and training material four major themes emerged to explain why drivers may deliberately deviate from following normative procedures designed by their managers. This included perceived pressure from safety and service goals, stress and fatigue during peak hours of operation, and workload created by security tasks. The results are organised in a succinct model that draws a link between drivers’ perceived pressure from multiple goals, and the changing driving conditions in which they perform. The study proposes ways for managers of urban commuter rail networks to understand the pressures that their drivers face in performing security tasks that are not part of their conventional job profile. The findings can inform changes in training methods, encourage drivers to discuss their reasons for deliberate rule violation, and support the design of security procedures more likely to be implemented