Biomagnetic field measurements and their interpretation using the dipole in a sphere model.

Although biomagnetism has advanced considerably in the last twenty years in terms of instrumentation and application, the fundamental requirement of relating the detected field to the underlying sources still has to rely on simple models. Most often the current dipole in a conducting sphere model is used. The exact geometry of the system under study is often ignored and clinically crucial decisions may be taken without understanding the limitations of this model. The work described in this thesis assesses those limitations, first by analysis of physical model generated data using the dipole in a sphere model. Dipole location, orientation, strength and sphere centre location were parameters used to fit calculated data to real data iteratively. These calculations were fully corrected for detector coil size and geometry. The systems investigated included whole and partial spheres and gel filled skulls. Dipoles placed in close proximity to boundaries were more difficult to fit to the dipole in a sphere model than those further away. As the boundary itself became more distinctly non- spherical, this difficulty increased. A goodness of fit parameter (R) was defined indicating accuracy of signal fitting. Surprisingly, in some examples, a low K value could be obtained for a poor set of predicted dipole parameters. However, if the fitting procedure incorporates the model sphere centre position as additional fitting parameters and a search is made through model sphere centre parameter space the effect of these (fortuitously) low K values could be avoided. The second half of the work applies the lessons of the first half to real biological systems. Magnetic fields emanating from a developing chick egg change during development. The egg provides a convenient system to investigate ionic fluxes involved with development and to test the appropriateness of the single dipole in a conducting sphere model in determining the source generators. Finally the human visual evoked response was used to Investigate the retinotopic representation of the cortex. The source locations suggested by this work using magnetic fields support earlier work which used electrical potential measurements, though a significant temporal difference of peak power between the two sets of sources is predicted by analysis of the data available from the two techniques

Influence of Foliar Sprays of Thiourea and Sulfuric Acid against Frost Injury in Berseem

Berseem (Trifolium alexandrinum L.) is an important winter season fodder crop which occupies 2 million ha area in India (Kumar et al., 2013). Berseem is generally grown as pure stands or in mixture with annual grass species for feeding to the livestock. During severe winter month periods from December to February, berseem growth is slow due to low minimum air temperature or cold wave or frost occurrence which affects fodder availability to the livestock. To increase growth of berseem either in pure stand or in mixture, farmers generally use excessive urea which not only affects nodule development in roots of legumes but also pollute the environment (Dogra and Dudeja, 1993). Mixture of berseem clover with cereal crop enhances total dry matter yield, improves fodder quality, reduces fertilizer use and also increases subsequent crop yield (Ross et al., 2004). Farmer harvests 3-4 cuttings of berseem up to late mid April as fodder for livestock and then leave the crop for seed production. After 3-4 cuts as green fodder, berseem plants retain less foliage, poor flowering and finally low seed production (Kumar et al., 2013). It is very essential that berseem crop attains sufficient height and tillering capacity during initial cuts for obtaining high fodder yield during slow growth and later on crop left for seed production produces good quantity and quality of seed. So, keeping this objective in view, a field experiment was designed to know the effect of different chemical foliar sprays during early cuts on the growth of berseem grown as pure stand and in mixture against very low minimum air temperature/frost injury

Fodder Yield and Quality of Lucerne (\u3cem\u3eMedicago sativa\u3c/em\u3e) Grown as Pure Stands and in Mixture with Oats (\u3cem\u3eAvena sativa\u3c/em\u3e), Mustard (\u3cem\u3eBrassica campestris\u3c/em\u3e) and Ryegrass (\u3cem\u3eLolium perenne\u3c/em\u3e) under Different Cutting Managements

Legume-cereal mixtures are important protein and carbohydrate sources for livestock and provide a balanced chemical composition for livestock feeding along with higher green forage yields than the pure stands (Berdahl et al. 2001; Albayrak and Ekiz, 2005). Lucerne is the most important rabi legume crop of Punjab grown under limited irrigation conditions and provides succulent, palatable and nutritious fodder to dairy animals. The fodder yield of first cut of lucerne is very low so it is usually grown in mixture with oats and or mustard. The information on the mixtures of lucerne and suitable cutting times is scant. This study was conducted to assess fodder yield and quality of lucerne mixtures with ryegrass, oat and mustard along with the effects of cutting time

Growth, yield and quality of turmeric (Curcuma longa L.) as influenced by planting method, plant density and planting material

A study was carried out at Ludhiana (Punjab) to evaluate the effect of planting method,plant density and planting material on growth, yield and quality of turmeric (Curcuma longa).The experiment consisted of two planting methods (flat and ridge), three plant densities(1,66,667; 1,11,111 and 83,333 plants ha-1) and three types of planting material (mother, primaryand secondary rhizomes). Fresh rhizome yield of 164.8 and 160.3 q ha-1 (pooled data) wasproduced in flat and ridge method of planting but the differences were non-significant. Closerplant spacing or higher plant density produced highest fresh, dry and processed turmericyield and it decreased with decrease in plant density; whereas, number and weight of rhizomesincreased with decrease in plant density. Use of mother rhizome as planting material resultedin better emergence (86.6% and 83.1%), taller plants (49.6 and 50.0 cm) with more number ofleaves and leaf area index (4.4 and 3.8), more tillers plant-1 (2.7 and 3.1), higher number(17.09 and 23.89) and weight (136.96 and 227.66 g) of total rhizomes plant-1 as compared touse of primary and secondary fingers as planting material during 2003-04 and 2004-05,respectively. Planting of mother rhizomes produced highest fresh (207.7 q ha-1), dry (46.0 qha-1) and processed (44.1 q ha-1) turmeric yield and it decreased significantly with decrease inseed size. Curcumin content did not change due to different planting methods, plant densitiesand planting materials. &nbsp

Effect of method of planting and harvesting time on growth, yield and quality of turmeric (Curcuma longa L.)

An experiment was conducted at Ludhiana (Punjab) to study the influence of method ofplanting (flat and ridge planting) and harvesting time (10 November-12 March) on growth,yield and of quality turmeric (Curcuma longa). Planting methods did not influence growth,yield and quality of turmeric significantly. Harvesting on 12th March produced maximumfresh rhizome yield of 28.94 t ha-1 (mean yield) of turmeric which was statistically on parwith 20th February (27.61 t ha-1) and 30th January (26.78 t ha-1) harvesting, but was significantlybetter than all the earlier harvesting dates. A similar trend was observed in processed turmericyield. The number and weight of rhizomes improved significantly with delay in harvesting.The oil and curcumin content also increased with delay in harvesting. &nbsp

Insect and Pest Management for Sustaining Crop Production Under Changing Climatic Patterns of Drylands

Climate change is alarming, particularly for agriculturists as it severely impacts the development, distribution, and survival of insects and pests, affecting crop production globally. Over time, climate change is drastically tumbling the crop productivity in all the cropping systems, whereas the dryland agriculture with existing low productivity is immensely hit. While all the existing species in drylands, including humans, are coping with extreme climate variations for millennia, future climate change predictions put dryland agriculture in a threat zone. Drylands support 38% of the world’s population; therefore, climate change coupled with population growth and global food security draws the attention of scientists towards sustainable crop production under changing trends. The intermingling and intermixing of various biological, hydrological, and geographical systems plus the anthropogenic factors continuously amplify the changes in the dryland systems. All of this brings us to one challenge: developing pest management strategies suitable for changing climatic patterns. In this complex agrology framework, integrated pest management (IPM) strategies, especially those involving early monitoring of pests using prediction models, are a way to save the show. In this chapter, we will summarize the direct and indirect effects of climate change on crop production, the biology of insect pests, the changing pest scenarios, the efficacy of current pest management tactics, and the development of next-generation crop protection products. Finally, we will provide a perspective on the integration of best agronomic practices and crop protection measures to achieve the goal of sustainable crop production under changing climatic trends of drylands

Density duct formation in the wake of a travelling ionospheric disturbance: Murchison Widefield Array observations

©2016. American Geophysical Union. Geomagnetically aligned density structures with a range of sizes exist in the near-Earth plasma environment, including 10-100 km wide VLF/HF wave-ducting structures. Their small diameters and modest density enhancements make them difficult to observe, and there is limited evidence for any of the several formation mechanisms proposed to date. We present a case study of an event on 26 August 2014 where a travelling ionospheric disturbance (TID) shortly precedes the formation of a complex collection of field-aligned ducts, using data obtained by the Murchison Widefield Array (MWA) radio telescope. Their spatiotemporal proximity leads us to suggest a causal interpretation. Geomagnetic conditions were quiet at the time, and no obvious triggers were noted. Growth of the structures proceeds rapidly, within 0.5 h of the passage of the TID, attaining their peak prominence 1-2 h later and persisting for several more hours until observations ended at local dawn. Analyses of the next 2 days show field-aligned structures to be preferentially detectable under quiet rather than active geomagnetic conditions. We used a raster scanning strategy facilitated by the speed of electronic beamforming to expand the quasi-instantaneous field of view of the MWA by a factor of 3. These observations represent the broadest angular coverage of the ionosphere by a radio telescope to date

Structure-Activity Studies Of 7-Heteroaryl-3-Azabicyclo[3.3.1]Non-6-Enes: A Novel Class Of Highly Potent Nicotinic Receptor Ligands

The potential for nicotinic ligands with affinity for the α4β2 or α7 subtypes to treat such diverse diseases as nicotine addiction, neuropathic pain, and neurodegenerative and cognitive disorders has been exhibited clinically for several compounds while preclinical activity in relevant in vivo models has been demonstrated for many more. For several therapeutic programs, we sought nicotinic ligands with various combinations of affinity and function across both subtypes, with an emphasis on dual α4β2-α7 ligands, to explore the possibility of synergistic effects. We report here the structure-activity relationships (SAR) for a novel series of 7-heteroaryl-3-azabicyclo[3.3.1]non-6-enes and characterize many of the analogues for activity at multiple nicotinic subtypes. © 2012 American Chemical Society