861 research outputs found
Targeting groundwater potential zones using Electrical resistivity and GIS techniques in Kadavanar Sub-basin, South India
Geographical Information System techniques are widely used to determine suitable sites for groundwater recharge through artificial recharge techniques. The present research work is to identify suitable locations for constructing artificial recharge structures in the Kadavanar Sub-basin, South India. People in the Sub-basin mainly depend on the groundwater resources for drinking and irrigation purposes. Groundwater resources are often overexploited in many parts of this Sub-basin to meet the water demand leading to groundwater consumption. A lot of surfaces and sub-surface information and criteria are required for mapping the groundwater recharge zone. This is where the geographic information system [GIS] provides the right impetus besides the groundwater prospective zone to harness multilayered spatial data so that multi-criteria analysis is possible. This analysis integrates historic rainfall data analysis, groundwater level fluctuation, stream network, aquifer thickness, land use/land cover and basin slope. Drainage map, slope map and land use/land cover maps were prepared from satellite imageries. Vertical electrical sounding (VES) geophysical survey with Schlumberger electrode configuration was also conducted in the basin at 50 locations to map the aquifer thickness. Spatial variation maps for groundwater level and aquifer thickness were generated using GIS. Weighted aggregation method was used in this study to obtain groundwater recharge maps. Finally, multi-criteria analysis has been carried out to identify and assess the potential sites for groundwater recharge according to the associated weightages. It is established that GIS is best suited for the mapping of groundwater recharge zones. A similar study can be extended to any other hard-rock region facing water crises
Identifying inhibitors of epithelial–mesenchymal plasticity using a network topology-based approach
Metastasis is the cause of over 90% of cancer-related deaths. Cancer cells undergoing metastasis can switch dynamically between different phenotypes, enabling them to adapt to harsh challenges, such as overcoming anoikis and evading immune response. This ability, known as phenotypic plasticity, is crucial for the survival of cancer cells during metastasis, as well as acquiring therapy resistance. Various biochemical networks have been identified to contribute to phenotypic plasticity, but how plasticity emerges from the dynamics of these networks remains elusive. Here, we investigated the dynamics of various regulatory networks implicated in Epithelial-mesenchymal plasticity (EMP)-an important arm of phenotypic plasticity-through two different mathematical modelling frameworks: a discrete, parameter-independent framework (Boolean) and a continuous, parameter-agnostic modelling framework (RACIPE). Results from either framework in terms of phenotypic distributions obtained from a given EMP network are qualitatively similar and suggest that these networks are multi-stable and can give rise to phenotypic plasticity. Neither method requires specific kinetic parameters, thus our results emphasize that EMP can emerge through these networks over a wide range of parameter sets, elucidating the importance of network topology in enabling phenotypic plasticity. Furthermore, we show that the ability to exhibit phenotypic plasticity correlates positively with the number of positive feedback loops in a given network. These results pave a way toward an unorthodox network topology-based approach to identify crucial links in a given EMP network that can reduce phenotypic plasticity and possibly inhibit metastasis-by reducing the number of positive feedback loops
Development, characterization and analysis of auxetic structures from braided composites and study the influence of material and structural parameters
Auxetic materials are gaining special interest in technical sectors due to their attractive mechanical behaviour.
This paper reports a systematic investigation on missing rib design based auxetic structures produced
from braided composites for civil engineering applications. The influence of various structural
and material parameters on auxetic and mechanical properties was thoroughly investigated. The basic
structures were also modified with straight longitudinal rods to enhance their strengthening potential
in structural elements. Additionally, a new analytical model was proposed to predict Poisson’s ratio
through a semi empirical approach. Auxetic and tensile behaviours were also predicted using finite element
analysis. The auxetic and tensile behaviours were observed to be more strongly dependent on their
structural parameters than the material parameters. The developed analytical models could well predict
the auxetic behaviour of these structures except at very low or high strains. Good agreement was also
observed between the experimental results and numerical analysis.University of Minho – UMINHO/BI/146/2012, under the scheme of ‘‘Strategic plan of
school of engineering – Agenda 2020: Multidisciplinary projects.
Hypocone Reduction and Carabelli’s Traits in Contemporary Jordanians and the Association between Carabelli’s Trait and the Dimensions of the Maxillary First Permanent Molar
The objective of this study is to determine the prevalence of expression and bilateralism of two dental morphological
traits in contemporary Jordanians: The hypocone reduction trait on the maxillary second permanent molar and Carabelli’s
trait on maxillary permanent first and second molars. Furthermore, inter-trait correlation and the relationship
of Carabelli’s traits with upper first molar dimensions were investigated. Three hundred subjects of school children at
their 10th grade and of an average age of 15.5±0.4 years were involved. Alginate impressions for the maxillary arch were
taken, dental casts were reproduced. The selected accurate casts were of 132 male- and 155 female-students. The frequencies
of hypocone reduction trait on the maxillary second molar and Carabelli’s trait on the maxillary molars were examined.
Buccolingual and mesiodistal diameters of the maxillary first molar were measured and recorded. Paired Sample t
test and Nonparametric Correlation analysis were used for data analysis. Hypocone reduction trait on the maxillary second
molar was found in 29.8 % of the examined students. Positive forms of Carabelli’s trait on first and second molars
were observed in 65.0 % and 3.8 %, respectively. Nonparametric correlation analysis revealed positive association between
Carabelli’s trait on first molar and hypocone reduction trait on the maxillary second molar. The presence of Carabelli’s
trait on first molar was strongly associated with the increase of buccolingual, but not the mesiodistal, diameter.
Bilateralism was found highly significant in the tested traits and both genders (p<0.001). This finding might be a sign
of relatively low environmental stresses in the living Jordanian population and/or great ability of its individuals to
buffer the adverse effects of such stresses
Is it worth treating category I failure patients with category II regimen?
Background: Very little information is available on the drug susceptibility profile among patients who are treated with
standardized short-course chemotherapy regimens under programme conditions.
Methods: Sputum samples were collected from new sputum smear-positive patients declared ‘failure’ after treatment with
Category I regimen under tuberculosis control programme using DOTS strategy from a rural area of Tamil Nadu.
Results: Of 1463 patients started on Category I regimen between May1999 and December 2002, 74 cases were declared
as ‘failures’ (smear positive at 5/6 months of treatment). We collected sputum samples from 60 (81%) of 74 ‘failures’ and
27% (16 of 60) of them were culture-negative for M tuberculosis and 17% (10 of 60) had organisms resistant to Isoniazid
and Rifampicin (MDR TB).
Conclusion: Based on the drug susceptibility profile at the time of ‘failure’, treating Category I ‘failures’ with Category
II regimen with close monitoring appears to be justified
Managing Congestion in Vehicular Networks Using Tabu Search
© 2018, Springer Nature Switzerland AG. In this era of communication, exponentially growing networks bring a lot of challenges to address for smoother network functionalities. Among them is efficiency in handling packet traffic to avoid and control congestion. A particular case is applicable to Vehicular Ad-hoc Networks, which are known with unbalanced resource utilisation, communication overheads, high transmission delay and least transmission capacity. This paper aims to minimise the delay and jitter for enhancing the Quality of Service (QoS) in Vehicular Adhoc Networks (VANET) using tabu search algorithm with multi-channel allocation capability. We proposed a scheme that prioritises each message considering the basis of message type or its substances, such as crisis, reference point, and administration oriented etc., and uses tabu search for scheduling the transmission of queued messages in order to enhance the efficiency, security, and durability of VANET. A comprehensive simulation is conducted to validate the proposed scheme and to evaluate the performances in comparison with other state-of-the-art approaches
Evaluation of System of Rice Intensification (SRI) in rice (Oryza sativa) - groundnut (Arachis hypogaea) system under Island ecosystem
Field experiment was conducted during wet and dry seasons of 2007-09 at Field Crops Research Farm of Central Island Agricultural Research Institute, Port Blair, Andaman and Nicobar Islands to evaluate System of Rice Intensification (SRI) in rice and its residual effect on groundnut in rice (Oryza sativa L.) – groundnut (Arachis hypogaea L.) systems. Time of planting, spacing and nitrogen practices evaluated significantly influenced the yield attributes and yield of rice, while the residual effect of N management practices had a positive influence on the yield attributes and yield of succeeding groundnut. Early planting in second fortnight of June with 20 cm × 20 cm spacing recorded higher panicles/m2 (9.1 %), higher number of filled grains/ panicle (108), higher grain yield (4 678 kg/ha), about 3% higher REY, productivity (26.8 kg/ha/day), and total profitability (` 62 882/ha) compared to the same time of planting with wider spacing (25 cm × 25 cm). Though application of 100% Recommended Dose of Nitrogen (RDN) through urea recorded highest grain yield (4 465 kg/ha) of rice, it was comparable with 50% RDN through Gliricidia + 50% RDN through urea and 75% RDN through Gliricidia + 25% RDN through urea. Application of 50% RDN through Gliricidia + 50% RDN recorded nearly 6% higher REY and ` 6 565/ha more profitability higher output energy in rice-groundnut sequence compared to application of 100% RDN through urea. N management practices of rice, in the crop sequence of rice- groundnut were found to improve the soil nitrogen status. Early planting of rice in second fortnight of June at 20 cm × 20 cm with the application of 50% RDN through Gliricidia + 50% RDN through urea can be recommended for achieving higher productivity, profitability and energy use efficiency of rice - groundnut system in Island ecosystem
Development and characterization of novel auxetic structures based on re-entrant hexagon design produced from braided composites
This paper reports the first attempt of developing macro-scale auxetic structures based on re-entrant
hexagon design from braided composite materials for civil engineering applications. Braided composite
rods (BCRs) were produced and arranged as longitudinal and horizontal elements to produce three
types of auxetic structures: (1) basic re-entrant hexagon structure, (2) basic structure modified by adding
straight longitudinal elements and (3): structure-2 modified by changing structural angle. The influence
of various material and structural parameters as well as structure type on Poisson's ratio and tensile
properties was thoroughly investigated. The auxetic behaviour was found to strongly depend on the
structural angle and straight elements, resulting in lower auxeticity with lower angles and in presence of
straight elements. Material parameters influenced the auxetic behaviour to a lesser extent and a decrease
in auxetic behaviour was noticed with increase in core fibre linear density and using stiffer fibres such as
carbon. The reverse effect was observed in case of tensile strength and work of rupture. Among these
structures, structure-3 exhibited good auxetic behaviour, balanced tensile properties, and high energy
absorption capacity and their auxetic behaviour could be well predicted with the developed analytical
model. Therefore, these novel structures present good potential for strengthening of civil structures.The authors gratefully acknowledge the financial support for carrying out this research work from University of Minho, under the scheme of "Strategic plan of school of engineering - Agenda 2020: Multidisciplinary projects.
- …