211 research outputs found

    Ecogeographical Amplitude and Habitat of Two Species of the Genus- Terminalia (Combretaceae) In the Central Niger Delta Areas in Rivers State

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    A systematic study involving phytogeography was carried out on two species of the genus-Terminalia in the Central Niger Delta Areas in River State. This research was aimed at establishing their biodynamic distribution and habitat in the study areas using the simple random sampling method based on standard procedure for ecological assessment. Result shows that both species are successfully adapted to the area as mesophytes but are distinct in all aspect, thus have marked preference for and /or by displaying restricted occurrence in certain ecological habitat. Terminalia ivorensis does occur wildly and in abundant in the forest than T. catappa, which is frequently cultivated around homes and residential areas, though occurred more in fresh water ecozone. Both species are deciduous with annual foliar senescence. Both species were also observed to be utilized for different purposes such as environmental conservation, beautification, parks and habitat and as shade creating plants and domestic source of fuel in the Central Niger Delt

    Irrigation and drainage in the new millennium

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    Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.Includes bibliographical references.A field study was conducted at Mashtul Pilot Area MPA (260 feddans' 1 feddan = 4200 m2) situated at north Zagazig to evaluate the performance of the long term constructed subsurface drainage system. The evaluation of grades, alignment and clogging of drain lines can give an indication of the system performance and efficiency. Three drainage units served by the same collector were selected. Four 30 m interval PVC lateral pipes were installed at different depths. The results revealed that, the collector drain slopes were either steep or flat while the overall slope of the collector drain was considered steep for about 45.50% of the sections and flat for the rest. On the other hand, some sections showed an inverse slope which can cause a decrease in the discharge rate. The regularity was classified as good for about 82% of the sections and moderate for the rest. The slope of the lateral drains was correct for 41.7% of those under study (12 lateral drains), steep for 16.60%, and flat for the rest, and the regularity was classified as poor except lateral number 71 which had moderate regularity in the first approach while, in the second approach 41.67% had moderate regularity and poor for the rest. Also the deviation of the drain pipes from the straight line was generally larger than pipe diameter. Consequently, air entrapment and sedimentation resulted. The results also indicated that, the average height of sedimentation inside lateral drains was 12.70 mm (618.30 gm/m drain length) while for collector drains, sediment was in 22.88% of pipe diameter. The average reduction in discharge capacity due to sedimentation for laterals and collectors upstream and downstream parts were 17.17%, 32.80% and 17.60% respectively. Also using Manning, Visser and Wesseling equations leads to different safety factors

    Determination of longitudinal aerodynamic derivatives using flight data from an icing research aircraft

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    A flight test was performed with the NASA Lewis Research Center's DH-6 icing research aircraft. The purpose was to employ a flight test procedure and data analysis method, to determine the accuracy with which the effects of ice on aircraft stability and control could be measured. For simplicity, flight testing was restricted to the short period longitudinal mode. Two flights were flown in a clean (baseline) configuration, and two flights were flown with simulated horizontal tail ice. Forty-five repeat doublet maneuvers were performed in each of four test configurations, at a given trim speed, to determine the ensemble variation of the estimated stability and control derivatives. Additional maneuvers were also performed in each configuration, to determine the variation in the longitudinal derivative estimates over a wide range of trim speeds. Stability and control derivatives were estimated by a Modified Stepwise Regression (MSR) technique. A measure of the confidence in the derivative estimates was obtained by comparing the standard error for the ensemble of repeat maneuvers, to the average of the estimated standard errors predicted by the MSR program. A multiplicative relationship was determined between the ensemble standard error, and the averaged program standard errors. In addition, a 95 percent confidence interval analysis was performed for the elevator effectiveness estimates, C sub m sub delta e. This analysis identified the speed range where changes in C sub m sub delta e could be attributed to icing effects. The magnitude of icing effects on the derivative estimates were strongly dependent on flight speed and aircraft wing flap configuration. With wing flaps up, the estimated derivatives were degraded most at lower speeds corresponding to that configuration. With wing flaps extended to 10 degrees, the estimated derivatives were degraded most at the higher corresponding speeds. The effects of icing on the changes in longitudinal stability and control derivatives were adequately determined by the flight test procedure and the MSR analysis method discussed herein

    DERIVATION OF THE LORENTZ-EINSTEIN TRANSFORMATION VIA ONE OBSERVER

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    Lorentz-Einstein transformation derived by Einstein in his theory of special relativity. Physical laws and principles are invariant in all Galilean reference frames under this transformation. The transformation in every day use in a host of contexts as in free solution of the Dirac equation in the modern field of heavy ion in atomic physics. Most books on theoretical physics and special theory of relativity and all research papers have derived the Eorentz-Einstein transformation using various propositions and employing two observers each located in Galilean system with relative motion receding the same events in the space-time manifold. This paper derives Lorentz-Einstein transformation by proposing just one observer using local coordinates of two Galilean system with relative motion following the track of a spherical pulse of light, which to our knowledge is not found in the literature

    Ecogeographical Amplitude and Habitat of Two Species of the Genus- Terminalia ( Combretaceae )In the Central Niger Delta Areas in Rivers State.

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    A systematic study involving phytogeography was carried out on two species of the genus- Terminalia in the Central Niger Delta Areas in River State. This research was aimed at establishing their biodynamic distribution and habitat in the study areas using the simple random sampling method based on standard procedure for ecological assessment. Result shows that both species are successfully adapted to the area as mesophytes but are distinct in all aspect, thus have marked preference for and /or by displaying restricted occurrence in certain ecological habitat. Terminalia ivorensis does occur wildly and in abundant in the forest than Terminalia catappa , which is frequently cultivated around homes and residential areas, though occurred more in fresh water ecozone. Both species are deciduous with annual foliar senescence. Both species were also observed to be utilized for different purposes such as environmental conservation, beautification, parks and habitat and as shade creating plants and domestic source of fuel in the Central Niger Delta. \ua9 JASE

    Co-producing an intervention for tobacco cessation and improvement of oral health among diabetic patients in Bangladesh

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    Abstract Background Tobacco consumption is a major risk factor for many diseases including diabetes and has deleterious effects on oral health. Diabetic patients are vulnerable to developing certain oral conditions. So far, no studies have attempted to co-develop a tobacco cessation intervention to be delivered in dental clinics for people with diabetes in Bangladesh. Aim To co-produce a tobacco cessation intervention for people with diabetes for use in dental clinics in Bangladesh. Objectives To assess: (1) tobacco use (patterns) and perceptions about receiving tobacco cessation support from dentists among people with diabetes attending the dental department of Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM) who smoke or use smokeless tobacco (ST) (2) current tobacco cessation support provision by the dentists of the dental department of BIRDEM (3) barriers and facilitators of delivering a tobacco cessation intervention at a dental clinic, and (4) to co-produce a tobacco cessation intervention with people with diabetes, and dentists to be used in the proposed context. Methods The study was undertaken in two stages in the dental department of BIRDEM, which is the largest diabetic hospital in Bangladesh. Stage 1 (July–August 2019) consisted of a cross-sectional survey among people with diabetes who use tobacco to address objective 1, and a survey and workshop with dentists working in BIRDEM, and consultations with patients to address objectives 2 and 3. Stage 2 (January 2020) consisted of consultations with patients attending BIRDEM, and a workshop with dentists to co-produce the intervention. Result All survey participants (n = 35) were interested in receiving tobacco cessation support from their dentist. We identified important barriers and facilitators to deliver tobacco cessation intervention within dental services. Barriers reported by dentists included lack of a structured support system and lack of training. As a facilitator, we identified that dentists were willing to provide support and it would be feasible to deliver tobacco cessation intervention if properly designed and embedded in the routine functioning of the dental department of BIRDEM. Through the workshops and consultations at stage 2, a tobacco cessation intervention was co-developed. The intervention included elements of brief cessation advice (using a flipbook and a short video on the harmful effects of tobacco) and pharmacotherapy. Conclusion Incorporation of tobacco cessation within dental care for people with diabetes was considered feasible and would provide a valuable opportunity to support this vulnerable group in quitting tobacco

    Improving the measurement of oral health-related quality of life: Rasch model of the oral health impact profile-14

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    Objectives: The 14-item Oral Health Impact Profile (OHIP-14) is the most frequently used instrument to measure oral health-related quality-of-life (OHRQoL) in adults. Despite its popularity, its psychometric properties have been predominantly investigated based on the classical test theory while the fundamental principles of measurement have not been fully assessed. Therefore, our aim was to investigate to what extent the OHIP-14 meets the fundamental requirments of measurements. Methods: We used the Rasch model to explore person-item-targeting, unidimensionality, local independence of items, invariance (differential-item-functioning, DIF), and the order of thresholds between response-options in the German version OHIP-14. We used data from osteoarthritis patients because hand disabilities and joint pain might influence oral hygiene. Furthermore, osteoarthritis in the temporomandibular-joint directly affects oral functioning. Results: Five-hundred sixteen patients were included (mean age 66.5 years [+/- 10.2; ranging from 34 to 89]; 71.3% [368] females). The OHIP-14 median total score was 0 (interquartile-range from 0 to 4), indicating a right-skewed distribution because many patients reported good OHRQoL. The instrument was found unidimensional. However, there was strong evidence of local dependency, disordered thresholds between responseoptions, and age-related DIF for item 5. A revised scoring scheme with three instead of five answer-options in all items and eliminating two items resolving local dependency, the newly adapted OHIP-12, showed better reliability and item-fit to the Rasch model than the original OHIP-14. Conclusions: This study assesses, for the first time, the OHIP-14 in terms of fundamental principles of measurement and proposes an item-reduced OHIP-12 as a psychometrically more accurate version of the instrument. Clinical significance: The Rasch model is essential to ensure instruments' precision and clinical meaningfulness when measuring OHRQoL in clinical practice and research. The OHIP-12, derived from the OHIP-14 by deleting two items due to local dependency, with a revised scoring scheme for all items distinguishing three answeroptions instead of five, represents a psychometrically improved version of the instrument.Clinical epidemiolog

    Limits of phytosanitation and host plant resistance towards the control of cassava viruses in Uganda

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    Published online: 30 Sept 2017Cassava (Manihot esculenta Crantz) and the viruses that infect it, notably cassava mosaic virus and cassava brown streak viruses, have a unique history of co-evolution and co-existence. While cassava originated in South America, both viruses and the diseases they cause have largely been limited to the East African region, where they have, and continue to be key yield-robbing stresses. For sustainable control, we assume that deployment of resistant varieties when carefully combined with phytosanitation will combat these viruses. We have thus generated empirical data and tested the limits, i.e., how long this strategy can last. This entailed the comparison of elite cassava varieties, one set of virus-indexed tissue culture plantlets, and the other set, re-cycled planting materials under farmer’s cyclic propagation for 6-23 years. Trials were established at diverse sites in Uganda. We observed that both officially-released and unofficially-released cassava varieties are common in farmer’s fields; these varieties have varying susceptibility levels to viruses. Worrisome was that some officially-released varieties like NASE 3 registered cassava mosaic disease (CMD) incidences of up to 71% (virus-indexed), which was not any different from its re-cycled counterparts. Other varieties like NASE 14 have maintained high levels of CMD resistance six years after official release. Predominant re-cycled cassava varieties notably TME 204, I92/0057, TME 14, and to a limited extent NASE 14, are key reservoirs for cassava brown streak disease (CBSD) associated viruses. These findings highlight the limits of phytosanitation, i.e., in areas like Kaberamaido associated with high CMD pressure, varieties NASE 1 and NASE 3 can not be recommended; on the contrary, these varieties can be deployed in Kalangala, where they can survive with phytosanitation. And for CBSD, the findings justify the urgent need for phytosanitation (community-led) and development of varieties with higher levels of resistance and/or tolerance, as no immune variety has so far been identified

    A resource for functional profiling of noncoding RNA in the yeast Saccharomyces cerevisiae

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    Eukaryotic genomes are extensively transcribed, generating many different RNAs with no known function. We have constructed 1502 molecular barcoded ncRNA gene deletion strains encompassing 443 ncRNAs in the yeast Saccharomyces cerevisiae as tools for ncRNA functional analysis. This resource includes deletions of small nuclear RNAs (snRNAs), transfer RNAs (tRNAs), small nucleolar RNAs (snoRNAs), and other annotated ncRNAs as well as the more recently identified stable unannotated transcripts (SUTs) and cryptic unstable transcripts (CUTs) whose functions are largely unknown. Specifically, deletions have been constructed for ncRNAs found in the intergenic regions, not overlapping genes or their promoters (i.e., at least 200 bp minimum distance from the closest gene start codon). The deletion strains carry molecular barcodes designed to be complementary with the protein gene deletion collection enabling parallel analysis experiments. These strains will be useful for the numerous genomic and molecular techniques that utilize deletion strains, including genome-wide phenotypic screens under different growth conditions, pooled chemogenomic screens with drugs or chemicals, synthetic genetic array analysis to uncover novel genetic interactions, and synthetic dosage lethality screens to analyze gene dosage. Overall, we created a valuable resource for the RNA community and for future ncRNA research
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