254 research outputs found
Pathogenic variability in Exserohilum turcicum and identification of resistant sources to turcicum leaf blight of maize (Zea mays L.)
Turcicum leaf blight of maize incited by Exserohilum turcicum (Pass.) Leonard and Suggs is the major limiting factor of maize production in temperate agro-ecologies. Disease management through host plant resistance is the most effective strategy. In the present study among 26 maize genotypes which were initially screened for resistance against E. turcicum under field conditions, 8 genotypes viz., PS 39, CML 451, CML 470, CML 472, VL 1030, VL 1018140, VL1018527 and SMI178-1 were found resistant when screened against twelve isolates of E. turcicum under artificial epiphytotic conditions. Eight genotypes viz., PS45, CML165, CML459, VL1249, VL0536, SMC-5, SMC-3 and KDL 211 were found moderately resistant with disease grade ranged from 2.1-2.5. These maize genotypes possess resistance to turcicum leaf blight can be used successfully in developing high yielding early maturing varieties for high altitude temperate agro-ecologies. The fungus E. turcicum is highly variable in nature. Variability studies on pathogenicity were conducted on twelve isolates of E. turcicum on eleven putative differential maize lines. During the present study a wide pathogenic variation was observed among the twelve isolates of E. turcicum. Cluster analysis on the basis of similarity or dissimilarity in reaction types exhibited by the differential hosts, clustered the isolates into 6 pathogenic groups. The isolates belonged to higher altitudes (Kti 10, Kti11, Kti5) were found to be more aggressive as compared to the isolates of low altitude areas
Management of diseases and insect-pests of French bean in Northwestern Indian Himalayan region using integrated approaches
French bean (Phaseolus vulgaris L.) production is adversely affected by many pathogens and insect-pests worldwide. In the present investigation, effect of different bio-fortified composts, organic amendments, botanicals and pesticides were evaluated against diseases and insect- pests of french bean. The results showed that seed treatment and drenching with Trichoderma harzianum strain 11, followed by soil application of fortified farmyard manure resulted in the lowest root rot incidence, highest germination, vigour and yield in french bean. In another set of experiment, soil incorporation of Parthenium hysterophorus, Urtica dioicaandLantana camarawere found to reduce root rot incidence with high germination and pod yield. Among the bioproducts and botanicals tested, foliar spray of cow dung extract (50%) reduced angular leaf spot, rust and bacterial blight severity by 51, 69 and 25 per cent, respectively. Among the fungicides, foliar application of azoxystrobin 23 SC (0.1%) and difenoconazole 25EC (0.025%), also reduced angular leaf spot and rust severity by 93 and 90 per cent, respectively. Among different insect pest management strategies under field conditions, cartap hydrochloride and batain seed extract registered low sucking bug (Chauliops choprai) population. Integrated approaches including bio-agents, botanicals along with chemicals for managing these diseases and insect-pests were found appropriate options. Out of six different IPM modules evaluated, seed treatment with carbendazim along with foliar spray of 0.1% azoxystrobin and cartap hydrochloride resulted in lowest root rot, rust, angular leaf spot, bacterial blight and Chaulopsis choprai bug population in French bean
Sensors for Harsh Environment: Radiation Resistant FBG Sensor System
This paper presents radiation resistant characteristics of fibre Bragg grating (FBG) sensors written in a photosensitive fiber and connected to a silica core radiation resistant optical fibre, aiming to develop a sensor system suitable for both sensing and data transmission in harsh environment. The silica core fluorine-down-doped clad optical fibre has been specifically designed and fabricated for this study using the modified chemical vapor deposition technique. Key waveguide parameters, including the width of the fluorine doped inner cladding have been optimized to obtain a low loss (<;0.2 dB/km) at the operating wavelength region of 1550 nm. The fibre fabrication process, mainly the deposition condition, has also been optimized to achieve smooth deposition and sintering of silica core layers, to minimize radiation induced absorption. As a result, radiation induced absorption of ~2.2 dB/km at 1550 nm under accumulated dose of 25 MRad at dose rate of 0.39 MRad/hr has been successfully achieved. To create an effective sensor system for harsh environmental conditions, this specialty fibre is connected to a number of FBGs (sensors) fabricated in photosensitive fibres prior to their extensive evaluations by being exposed to different accumulated dose of gamma radiation. Their corresponding Bragg wavelength shifts (BWS) and peak amplitudes were continuously monitored. It was found that the radiation induced BWS can be greatly reduced by shielding the sensors using stainless steel tubing. The temperature sensitivity and peak amplitude were found to be largely unchanged before and after exposure to Gamma radiation of 25 MRad which shows their potential use for temperature measurements in radiation environments with an uncertainty of around 0.1 °C
Biplot analysis of genotype × environment interactions and identification of stable sources of resistance to Ascochyta blight in chickpea (Cicer arietinum L.)
Ascochyta blight (AB) caused by Ascochyta rabei (Pass.) Labr. is one of the most important constraints that limits the productivity of chickpea (Cicer arietinum L.). The absence of high levels of stable resistant sources to the pathogen has necessitated the continued search and identification of new sources of resistance. The main aim of this work was to identify new sources of resistance to AB and validate their stability across multi-environments. A collection of 424 elite chickpea genotypes were evaluated for AB resistance under controlled environmental conditions in 2005–2006 at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India. Fifty-one genotypes with AB severity ≤3.0 (based on the 1–9 scale) were selected for a second round of evaluation in 2006–2007 at ICRISAT. Based on the results obtained during both years, an Ascochyta Blight Nursery (ABN) was established to evaluate the selected 29 chickpea genotypes, including 4 germplasm lines, 24 breeding lines and a highly susceptible line. The nursery was evaluated at 3 locations (Almora, Dhaulakuan and Ludhiana) in India over three crop seasons (2007–2008, 2008–2009 and 2009–2010) and under controlled environment conditions at ICRISAT to further confirm the stable performance of these genotypes. Analysis of variance revealed highly significant effects of year, location (year), genotype and genotype × location (year) interaction. The genotype and genotype × environment (GGE) biplot analyses of multi-environment data showed that resistance of five genotypes (EC 516934, ICCV 04537, ICCV 98818, EC 516850 and EC 516971) had mean disease severity ≤3.0 on the 1–9 scale and the reactions were consistent across the environments. Genotype EC 516934 was found resistant to AB at the seedling stage in the controlled environment at ICRISAT. The remaining genotypes showed moderately resistant reaction (3.0–5.0) to AB under controlled environment conditions. A significant positive correlation was found between the performance of the genotypes under controlled environment and field screening conditions (r = 0.70; P < 0.01). The resistant genotypes identified in the present study would be useful in breeding programs as stable resistant donors to evolve agronomically desirable AB resistant varietie
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Driving factors of aerosol properties over the foothills of central Himalayas based on 8.5 years continuous measurements
This study presents analysis of in situ measurements conducted over the period 2005–2014 in the Indian Himalayas to give a thorough overview of the factors and causes that drive aerosol properties. Aerosol extensive properties (namely, particle number concentration, scattering coefficient, equivalent black carbon, PM2.5, and PM10) have 1.5–2 times higher values in the early to late afternoon than during the night, and a strong seasonality. The interannual variability is ±20% for both PM2.5 and total particle number concentration. Analysis of the data shows statistically significant decreasing trends of −2.3 μg m−3 year−1 and −2.7 μg m−3 year−1 for PM2.5 and PM10, respectively, over the study period. The mountainous terrain site (Mukteshwar, MUK) is primarily under the influence of air from the plains. This is due to convective transport processes that are enhanced by local and mesoscale topography, leading to pronounced valley/mountain winds and consequently to atmospheric boundary layer air lifting from the plains below. The transport from plains is evident in seasonal‐diurnal patterns observed at MUK. The timing of the patterns corresponds with changes in turbulence and water vapor (q). According to our analysis, using these as proxies is a viable method for examining boundary layer influence in the absence of direct atmospheric boundary layer height measurements. Comparing the measurements with climate models shows that even regional climate models have problems capturing the orographic influence accurately at MUK, highlighting the importance of long‐term direct measurements at multiple points to understand aerosol behavior in mountainous areas
Correction for a measurement artifact of the Multi-Angle Absorption Photometer (MAAP) at high black carbon mass concentration levels
The Multi-Angle Absorption Photometer (MAAP) is a widely-used instrument for aerosol black carbon (BC) measurements. In this paper, we show correction methods for an artifact found to affect the instrument accuracy in environments characterized by high black carbon concentrations. The artifact occurs after a filter spot change – as BC mass is accumulated on a fresh filter spot, the attenuation of the light (raw signal) is weaker than anticipated. This causes a sudden decrease, followed by a gradual increase in measured BC concentration. The artifact is present in the data when the BC concentration exceeds ~3 μg m<sup>−3</sup> at the typical MAAP flow rate of 16.7 L min<sup>−1</sup> or 1 m<sup>3</sup> h<sup>−1</sup>. The artifact is caused by erroneous dark counts in the photodetector measuring the transmitted light, in combination with an instrument internal averaging procedure of the photodetector raw signals. It was found that, in addition to the erroneous temporal response of the data, concentrations higher than 9 μg m<sup>−3</sup> (at the flow rate of 16.7 L min<sup>−1</sup>) are underestimated by the MAAP. The underestimation increases with increasing BC accumulation rate. At a flow rate of 16.7 L min<sup>−1</sup> and concentration of about 24 μg m<sup>−3</sup> (BC accumulation rate ~0.4 μg min<sup>−1</sup>), the underestimation is about 30%. There are two ways of overcoming the MAAP artifact. One method is by logging the raw signal of the 165° photomultiplier measuring the reflected light from the filter spot. As this signal is not affected by the artifact, it can be converted to approximately correct absorption and BC values. However, as the typical print formats of the MAAP do not give the reflected signal as an output, a semi-empirical correction method was developed based on laboratory experiments to correct for the results in the post-processing phase. The correction function was applied to three MAAP datasets from Gual Pahari (India), Beijing (China), and Welgegund (South Africa). In Beijing, the results could also be compared against a photoacoustic spectrometer (PAS). The correction improved the quality of all three MAAP datasets substantially, even though the individual instruments operated at different flow rates and in different environments
Bardet-Biedl syndrome with end-stage kidney disease in a four-year-old Romanian boy: a case report
<p>Abstract</p> <p>Background</p> <p>Bardet-Biedl syndrome is a significant genetic cause of chronic kidney disease in children. Kidney abnormalities are a major cause of morbidity and mortality in Bardet-Biedl syndrome, but the onset of end-stage renal disease at an early age and continuous ambulatory peritoneal dialysis, however, are not commonly mentioned in the literature.</p> <p>Case presentation</p> <p>We present the case of a four-year-old Romanian boy who presented to our department with 'febrile seizures'. After an initial evaluation, we diagnosed our patient as having hypertension, severe anemia and end-stage renal disease. He met the major and minor criteria for the diagnosis of Bardet-Biedl syndrome and underwent continuous ambulatory peritoneal dialysis.</p> <p>Conclusions</p> <p>Close follow-up for renal involvement in patients with Bardet-Biedl syndrome and Alström syndrome from an early age is highly recommended to prevent end-stage renal disease and so renal replacement therapy can be started immediately.</p
An overview of the first decade of PollyNET : an emerging network of automated Raman-polarization lidars for continuous aerosol profiling
© Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 LicenseA global vertically resolved aerosol data set covering more than 10 years of observations at more than 20 measurement sites distributed from 63° N to 52° S and 72° W to 124° E has been achieved within the Raman and polarization lidar network PollyNET. This network consists of portable, remote-controlled multiwavelength-polarization-Raman lidars (Polly) for automated and continuous 24/7 observations of clouds and aerosols. PollyNET is an independent, voluntary, and scientific network. All Polly lidars feature a standardized instrument design with different capabilities ranging from single wavelength to multiwavelength systems, and now apply unified calibration, quality control, and data analysis. The observations are processed in near-real time without manual intervention, and are presented online at http://polly.tropos.de/. The paper gives an overview of the observations on four continents and two research vessels obtained with eight Polly systems. The specific aerosol types at these locations (mineral dust, smoke, dust-smoke and other dusty mixtures, urban haze, and volcanic ash) are identified by their Ångström exponent, lidar ratio, and depolarization ratio. The vertical aerosol distribution at the PollyNET locations is discussed on the basis of more than 55 000 automatically retrieved 30 min particle backscatter coefficient profiles at 532 nm as this operating wavelength is available for all Polly lidar systems. A seasonal analysis of measurements at selected sites revealed typical and extraordinary aerosol conditions as well as seasonal differences. These studies show the potential of PollyNET to support the establishment of a global aerosol climatology that covers the entire troposphere.Peer reviewe
Characterisation of neonicotinoid insecticides in the cocoa-producing Owena River basin of Nigeria by a QuEChERS method coupled to liquid chromatography-tandem mass spectrometry
Spatial distributions and seasonal cycles of aerosol climate effects in India seen in a global climate-aerosol model
Climate-aerosol interactions in India are studied by employing the global climate-aerosol model ECHAM5-HAM and the GAINS inventory for anthropogenic aerosol emissions. Model validation is done for black carbon surface concentrations in Mukteshwar and for features of the monsoon circulation. Seasonal cycles and spatial distributions of radiative forcing and the temperature and rainfall responses are presented for different model setups. While total aerosol radiative forcing is strongest in the summer, anthropogenic forcing is considerably stronger in winter than in summer. Local seasonal temperature anomalies caused by aerosols are mostly negative with some exceptions, e.g., parts of northern India in March-May. Rainfall increases due to the elevated heat pump (EHP) mechanism and decreases due to solar dimming mechanisms (SDMs) and the relative strengths of these effects during different seasons and for different model setups are studied. Aerosol light absorption does increase rainfall in northern India, but effects due to solar dimming and circulation work to cancel the increase. The total aerosol effect on rainfall is negative for northern India in the months of June-August, but during March-May the effect is positive for most model setups. These differences between responses in different seasons might help converge the ongoing debate on the EHPs and SDMs. Due to the complexity of the problem and known or potential sources for error and bias, the results should be interpreted cautiously as they are completely dependent on how realistic the model is. Aerosol-rainfall correlations and anticorrelations are shown not to be a reliable sole argument for deducing causality
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