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Weed management is the major challenge to the success of boro rice (rice grown during Dec–Jan to May–Jun, also known as summer rice) in Southern Asia. Herbicide seems to be a cost effective and strategic tool from an agronomic view point to control weeds; however, herbicide application can potentially interfere with soil enzyme activity and microbial biomass carbon (MBC). A field study was conducted in 2012/13 and 2013/14 to evaluate the performance of sole and combined application of different pre-emergence herbicides in comparison to manual weeding in boro rice. Lowest weed density, biomass and highest weed control efficiency (~83%) were recorded with the pyrazosulfuron ethyl, causing higher grain yield (6.7 Mg ha−1 in 2012/13 and 4.5 Mg ha−1 in 2013/14) than treatments with chlorimuron + metsulfuron-methyl, bensulfuron methyl + pretilachlor, butachlor fb 2,4D, butachlor and cono-weeder. Among, the herbicidal treatments butachlor caused lower grain yield and higher weed density and biomass when compared to the others. Although grain yield was highest in weed-free treatments but net returns and (B:C) benefit cost ratio was highest for pyrazosulfuron ethyl due to high cost of hand weeding. After 15 days of herbicide application, lowest microbial biomass carbon was recorded with bensulfuron methyl + pretilachlor, whereas lower values of dehydrogenase and fluorescein diacetate activities were observed with the application of chlorimuron + metsulfuron-methyl at 15 days after herbicide application. Our results suggest that pyrazosulfuron ethyl is one broad-spectrum and economically effective herbicide for controlling weeds as an alternative to labour consuming hand weeding in boro rice cultivation.
In recent years, the government of Bangladesh has encouraged private sector involvement in producing mid-level health cadres including Medical Assistants (MAs). The number of MAs produced has increased significantly. We assessed students’ characteristics, educational services, competencies and perceived attitudes towards health service delivery in rural areas.
We used a mixed method approach using quantitative (questionnaire survey) and qualitative (key informant interviews and roundtable discussion) methods. Altogether, five public schools with 238 students and 30 private schools with 732 students were included. Statistical analyses were performed using STATA v-12. Qualitative data were analyzed thematically.
The majority of the students in both public (66%) and private medical assistant training schools (MATS) (61%) were from rural backgrounds. They spent the majority of their time in classroom learning (public 45% versus private 42%) and the written essay exam was the common form of a students’ performance assessment. Compared with students of public MATS, students of private MATS were more confident in different aspects of educational areas, including managing emerging health needs (P<0.001); evidence-based practice (P=0.002); critical thinking and problem solving (P=0.02), and use of IT/computer skills (P<0.001). Students were aware of not having adequate facilities in rural areas (public 71%, private 65%), but they perceived working in rural areas will offer several benefits, including use of learnt skills; friendly rural people; and opportunities for real-life problem solving, etc.
This study provides a current picture of MATS students’ characteristics, educational services, competencies and perception towards working in rural areas. The MA students in both private and public sectors showed a greater level of willingness to serve in rural health facilities. The results are promising to improve health service delivery, particularly in rural and hard-to-reach areas of Bangladesh.
Large areas of rainfed lowlands of Asia annually experienced flash flooding during the rice-growing season, which is an important abiotic stress that adversely affect grain yield of rice (Oryza sativa L.) crop. Submergence stress is a common environmental challenge for agriculture sustainability in these areas because lack of high-yielding, flood-tolerant cultivars. In this study, IR64-Sub1 and IR64 were compared for their tolerance to submergence at active tillering (AT), panicle initiation (PI) and heading (H) stages with nitrogen and phosphorus application time. We evaluated the role of cultivars, stage of submergence and N and P application on phenology, leaf senescence (LS), photosynthetic (Pn) rate, yield attributes and yield. Under non-submerged conditions, no difference was observed in phenology, Pn rate and yield of both cultivars. Submergence substantially reduced biomass, Pn rate, yields attributes and yield across cultivars with more drastic reduction in IR64. Submergence at H stage proves to be most detrimental. Nitrogen application after desubmergence with basal P improved the Pn rate resulting in significantly higher yield and yield components. Nitrogen application before submergence resulted in increased LS and ethylene accumulation in shoots leading to drastic reduction in growth, Pn rate and yield. Crop establishment and productivity could therefore be enhanced in areas where untimely flooding is anticipated by avoiding N application before submergence and applying N after desubmergence with basal P (phosphorus).
This Summary for Policymakers presents key findings from the Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). The SREX approaches the topic by assessing the scientific literature on issues that range from the relationship between climate change and extreme weather and climate events (‘climate extremes’) to the implications of these events for society and sustainable development. The assessment concerns the interaction of climatic, environmental, and human factors that can lead to impacts and disasters, options for managing the risks posed by impacts and disasters, and the important role that non-climatic factors play in determining impacts. Box SPM.1 defines concepts central to the SREX.
The character and severity of impacts from climate extremes depend not only on the extremes themselves but also on exposure and vulnerability. In this report, adverse impacts are considered disasters when they produce widespread damage and cause severe alterations in the normal functioning of communities or societies. Climate extremes, exposure, and vulnerability are influenced by a wide range of factors, including anthropogenic climate change, natural climate variability, and socioeconomic development (Figure SPM.1). Disaster risk management and adaptation to climate change focus on reducing exposure and vulnerability and increasing resilience to the potential adverse impacts of climate extremes, even though risks cannot fully be eliminated (Figure SPM.2). Although mitigation of climate change is not the focus of this report, adaptation and mitigation can complement each other and together can significantly reduce the risks of climate change. [SYR AR4, 5.3]
We have performed x-ray photon correlation spectroscopy (XPCS) measurements on a polymer-bilayer system comprised of 100 nm polystyrene film on top of an 80 nm polybromostyrene film, supported on a Si substrate. In order to distinguish the dynamics at the top interface from that at the polymer-polymer interface we have performed the measurement at grazing incidence. In this geometry, a standing wave is set up in the film. We derive a relation for the intensity of the standing wave and the resulting diffuse scattering. This model is compared with the measured diffuse scattering from which we extract a value of 0.7±0.4 dyne/cm for the surface tension between PS and PBrS at 180C. XPCS was then measured in each of two standing wave conditions, first where diffuse scattering only occurs at the polymer-vacuum interface and then where it only occurs at the interior polymer-polymer interface. The measured time correlation functions for each of the two interfaces show clear differences, with the polymer-polymer interface exhibiting much slower dynamics.
There is considerable controversy surrounding the optimum treatment of advanced hypopharyngeal cancers. Curative radiotherapy with surgical salvage in reserve is an accepted protocol as is also a combined treatment of surgery and radiotherapy. The present study is a retrospective analysis of the survival results of 195 cases treated in a single centre. The combined surgery and radiotherapy group comprised a greater number of pyriform fossa and post-cricoid tumours whereas, the curative radiotherapy group had a higher proportion of posterior pharyngeal wall tumours. Actuarial two-year disease-free survival rates were significantly better with combined treatment when results of stage III and IV lesions (164 patients) of all sites are taken together, as compared to those obtained with curative radiotherapy without salvage (p = 0.000) or radiotherapy with surgical salvage for residual/recurrent tumours (p = 0.0021).
Lithium niobate single crystal is an excellent material for various optical applications such as frequency conversion, optical switches, optical modulators and others. An automatic diameter control Czochralski crystals growth system has been designed and fabricated. A brief description of the entire system along with software developed has been described. With optimized growth parameters, pure and Fe/Mn doped crystals have been successfully grown using this system. Preliminary characterizations of these crystals have also been presented.
Isolates of Cryptosporidium muris and C. serpentis were characterized from different hosts using nucleotide sequence
analysis of the rDNA 18S and ITS1 regions, and the heat-shock (HSP-70) gene. Phylogenetic analysis confirmed
preliminary evidence that C. muris is not a uniform species. Two distinct genotypes were identified within C. muris; (1)
C. muris genotype A; comprising bovine and camel isolates of C. muris from different geographical locations, and (2) C.
muris genotype B comprising C. muris isolates from mice, a hamster, a rock hyrax and a camel from the same enclosure.
These 2 genotypes may represent separate species but further biological and molecular studies are required for
In this work the effect of grain size and magnetic switching volume on media noise due to intergranular coupling for CoCrTaPt/Cr thin film media deposited at substrate temperature of 160 and 260°C are investigated. The film deposited at substrate temperature of 260°C showed weaker intergranular interaction and lower media noise compared to the film deposited at 160°C. The magnetic switching volume (V*) is an important consideration for thermal stability and media noise in high density recording media. The magnetic switching volume V* for the film deposited at 160 and 260°C was calculated to be 3.7 x 10-18 and 3.2 x 10-18 cm3 respectively. The magnetic switching volume is correlated to the average Co-alloy grain size, media noise and the interactions between the grains.
Thin hydrogenated amorphous silicon carbide (a-SiC:H) films were grown at substrate temperatures ranging from 200 K to 600 K by remote ECR plasma-enhanced CVD. Mono- and trimethylsilane were used as single source precursors. The films grown using both precursors were compared as a function of temperature by in situ multiple internal reflection Fourier transform infrared (MIR-FTIR) spectroscopy. The difference in growth temperature leads to changes in both the hydrogen content and the composition of the film. At low growth temperature, films incorporate high concentrations of intact methyl group and a mixture of SiHx (x=1–3) groups, with a polysilane-like structure. At higher temperatures, the hydrogen content decreases. This decrease is observed in two different ways: (1) a loss of highly hydrogenated SiHx groups (SiH3 or SiH2); and (2) a shift from methyl groups to CH2 and CH bonding. However, the temperature dependence of each functional group is found to be different for the two precursors.
The nature of the disordered state of hydrogenated amorphous silicon is examined for the first time by measurement of anelastic relaxation behavior. It is demonstrated that local structural units and their modifications control the relaxations in these films under different conditions of deposition, aging, and light exposure. Specifically, the light-induced state in this material is shown to be characterized by four distinct relaxations.
A field experiment conducted for two cropping seasons (1976–7 and 1977–8) showed that a fodder crop of Egyptian clover (Trifolium alexandrinum) increased the grain yield of a subsequently grown maize crop. Lathyrus (Lathyrus sativus) and peas (Pisum sativum) were less effective in this regard.
Field experiments made for 4 years between 1976–7 and 1979–80 in a semi-arid environment of north-west India showed that the productivity of dryland unirrigated wheat can be increased considerably by adjusting the date of sowing to conducive atmospheric temperatures. Sowing in the middle of November when daily mean temperatures ranged between 19 and 21 °C produced yields ranging between 2·6and 3·5t/ha (averaged over the 4 years) compared with 1·4–3·3 t/ha obtained from the crop sown by mid-October when the daily mean temperature ranged between 24 and 26 °C. The tall cultivar C 306, a derivative of winter x spring wheat cross, could withstand sowing at higher temperatures (mid-October) more than the spring wheats. High temperatures prevailing during the seedling stage of spring wheats shortened their vegetative growth and initiated early differentiation. Night temperatures above 13 °C coupled with day temperatures of 33–35 °C in the last fortnight of October adversely affected the tillering of spring wheats sown on 15 October and produced smaller spikes with few fertile spikelets.
The historicity of the two Indian epics, viz., the Mahābhārata and the Rāmāyana, has been the subject of heated debate ever since these epics attracted the attention of scholars, both in India and abroad. Thus, while there are some who hold that every event mentioned in these epics is historically true, there are others who regard them as mere figments of the imagination. Apart from the possibility that ‘orthodoxy’ and ‘reactionary attitude’ may respectively be partly responsible for such extremely divergent views, the confusion seems to arise from the fact that these epics are neither contemporary documentation of the episodes concerned nor have their texts remained immune from large-scale interpolations.
The growth of crystals from solution is greatly influenced by buoyancy driven convection. In a low-g environment, convection is greatly suppressed and diffusion becomes the predominant mechanism for thermal and mass transport. An experiment to grow TGS crystals by solution technique during the orbital Spacelab III mission has been designed. Crystals are grown by a new and unique technique of extracting heat from the crystal through a sting. The cooling at the sting tip is responsible for the desired supersaturation near the growing crystal. Calculations indicate that the cooled sting technique for solution crystal growth is necessary in low-g to maintain a maximum growth rate of 1 mm/day. Results of groundbased work in support of the flight experiment are discussed.
As late as 1920 it was believed that civilization on the Indian subcontinent dated back only to the time of Alexander's invasion in the 4th century b.c. and that everything before that was “dark”. This assumption was made in spite of the fact that literary evidence pointed to the contrary. However, in 1921 the “belief” received its first blow when Daya Ram Sahni discovered the site of Harappa; the second one came just a year later when R. D. Banerji discovered Mohenjo-daro. Subsequent excavations at these two sites and at another site called Chanhu-daro, respectively by M. S. Vats, John Marshall, and E. J. H. Mackay, brought to light fuller details of the civilization which encompassed the Indus valley in the 3rd millennium b.c. The more recent work at Amri, Damb Sadaat, Gumla, Jalilpur, Kalibangan, Kot Diji, Lothal, Sarai Khola, and Surkotda has added new dimensions to our knowledge of this civilization.
The production rates of bacteria have been measured in the rumen of zebu calves and buffalo calves. The animals were fed green oat continuously at 2 h intervals. [35S]sodium sulphate was fed to the animals for 5 days at 2 h intervals by mixing in the feed. On the sixth day the radioactive feed was stopped and replaced by non-radioactive feed. The decline in the specific radioactivity of bacterial cells in the rumen as a function of time was taken for calculating t/2. Simultaneously rumen volume was determined and pool size of bacterial cells was calculated in the rumen. A mathematical equation was applied to calculate the production rates of bacteria. The production rates of bacteria, on average, were 100·5 and 72·3 mg/min for buffalo calves and zebu calves, respectively.
The nymphs that are here described belong to those species the biology of which has been discussed in a previous paper (Lal, 1934 b). The plan followed was the one originally adopted by Ferris (1923), in which descriptions and illustrations of all morphological features important in the identification of the species of the nymph, apart from the adult, were prepared from careful examination of specimens mounted for microscopic observation. The importance of such a study has been increasingly appreciated in the last decade, both from the economic and the systematic points of view. Harmful species of Psyllidæ are mainly injurious because of the feeding activities of their immature stages, and there are but two species known, Psyllia pyricola Först. and Paratrioza cockerelli Sulc., in which the adults have also been found to be capable of causing injury. On the other hand, the specific determination of immature stages has been rendered difficult owing to the fact (first) that the published descriptions of individual species of nymphs are often found to be applicable to species other than those to which the particular description refers; and (second) that sometimes the nymphs of two closely allied species are distinguished by such marked differences as to warrant the adults being assigned to different genera and even subfamilies. Such cases have been mentioned by Crawford (1919), Ferris (1928 a), Husain and Nath (1927), and have been summarised by Rahman (1932) in the introductory part of his paper. The present descriptions have, therefore, been prepared with the avowed objects of facilitating the determination of individual species, where comparison with allied species is impossible owing to lack of available material, and also of assessing the value of the various nymphal characters with a view to establishing a classification based on these as contrasted with one based upon the characters of the adults.