5,293 research outputs found

    Response of Banana "Williams Hybrid" to Nitrogen, Phosphorus and Potassium Fertilization

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    Field experiments were conducted at the National Institute for Promotion of Horticultural Exports (NIPHE) research farm during the period of 2001 to 2002 to determine the effects of nitrogen, phosphorus and potassium levels on growth parameters, earliness, nutrient uptake, yield and yield components of "William's hybrid" banana cultivar. Treatments included 5 N levels (0, 69, 138, 207 and 276g N/mat/year), 2 P levels (0 and 20 g P/mat/year) and 2 K levels (0 and 41 g K/mat/year) . The treatments were arranged in a randomized complete block design with 3 replications. Banana growth, yield and yield components were significantly increased by N and K application. The highest vegetative growth parameters, yield and yield components were obtained with the application of 207 g N/mat/year in combination with 41 g K/mat/year. Application of N in combination with K also resulted in a significant reduction in the period from plant-ing to shooting and from shooting to fruit maturation. The shortest number of days to shooting were obtained with the application of 276 g N/mat/year. Application of N, P and K also resulted in increased leaf N, P and K contents. Application of P alone or in combinations with N and K had no significant effects on growth or yield parameters

    Biochemical characterization and DNA repair pathway interactions of Mag1-mediated base excision repair in Schizosaccharomyces pombe

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    The Schizosaccharomyces pombe mag1 gene encodes a DNA repair enzyme with sequence similarity to the AlkA family of DNA glycosylases, which are essential for the removal of cytotoxic alkylation products, the premutagenic deamination product hypoxanthine and certain cyclic ethenoadducts such as ethenoadenine. In this paper, we have purified the Mag1 protein and characterized its substrate specificity. It appears that the substrate range of Mag1 is limited to the major alkylation products, such as 3-mA, 3-mG and 7-mG, whereas no significant activity was found towards deamination products, ethenoadducts or oxidation products. The efficiency of 3-mA and 3-mG removal was 5–10 times slower for Mag1 than for Escherichia coli AlkA whereas the rate of 7-mG removal was similar to the two enzymes. The relatively low efficiency for the removal of cytotoxic 3-methylpurines is consistent with the moderate sensitivity of the mag1 mutant to methylating agents. Furthermore, we studied the initial steps of Mag1-dependent base excision repair (BER) and genetic interactions with other repair pathways by mutant analysis. The double mutants mag1 nth1, mag1 apn2 and mag1 rad2 displayed increased resistance to methyl methanesulfonate (MMS) compared with the single mutants nth1, apn2 and rad2, respectively, indicating that Mag1 initiates both short-patch (Nth1-dependent) and long-patch (Rad2-dependent) BER of MMS-induced damage. Spontaneous intrachromosomal recombination frequencies increased 3-fold in the mag1 mutant suggesting that Mag1 and recombinational repair (RR) are both involved in repair of alkylated bases. Finally, we show that the deletion of mag1 in the background of rad16, nth1 and rad2 single mutants reduced the total recombination frequencies of all three double mutants, indicating that abasic sites formed as a result of Mag1 removal of spontaneous base lesions are substrates for nucleotide excision repair, long- and short-patch BER and RR

    Sex distribution of offspring-parents obesity: Angel's hypothesis revisited

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    This study, which is based on two cross sectional surveys' data, aims to establish any effect of parental obesity sex distribution of offspring and to replicate the results that led to the hypothesis that obesity may be associated with sex-linked recessive lethal gene. A representative sample of 4,064 couples living in Renfrew/Paisley, Scotland was surveyed 1972-1976. A total of 2,338 offspring from 1,477 of the couples screened in 1972-1976, living in Paisley, were surveyed in 1996. In this study, males represented 47.7% among the total offspring of the couples screened in 1972-1976. In the first survey there was a higher male proportion of offspring (53%, p < 0.05) from parents who were both obese, yet this was not significant after adjustment for age of parents. Also, there were no other significant differences in sex distribution of offspring according to body mass index, age, or social class of parents. The conditions of the original 1949 study of Angel (1949) (which proposed a sex-linked lethal recessive gene) were simulated by selecting couples with at least one obese daughter. In this subset, (n = 409), obesity in fathers and mothers was associated with 26% of offspring being male compared with 19% of offspring from a non-obese father and obese mother. Finally we conclude that families with an obese father have a higher proportion of male offspring. These results do not support the long-established hypotheses of a sex-linked recessive lethal gene in the etiology of obesity

    Participatory plant breeding: a way to arrive at better-adapted onion varieties

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    The search for varieties that are better adapted to organic farming is a current topic in the organic sector. Breeding programmes specific for organic agriculture should solve this problem. Collaborating with organic farmers in such programmes, particularly in the selection process, can potentially result in varieties better adapted to their needs. Here, we assume that organic farmers' perceptive of plant health is broader than that of conventional breeders. Two organic onion farmers and one conventional onion breeder were monitored in their selection activities in 2004 and 2005 in order to verify whether and in which way this broader view on plant health contributes to improvement of organic varieties. They made selections by positive mass selection in three segregating populations under organic conditions. The monitoring showed that the organic farmers selected in the field for earliness and downy mildew and after storage for bulb characteristics. The conventional breeder selected only after storage. Farmers and breeder applied identical selection directions for bulb traits as a round shape, better hardness and skin firmness. This resulted in smaller bulbs in the breeders’ populations, while the bulbs in the farmer populations were bigger than in the original population. In 2006 and 2007 the new onion populations will be compared with each other and the original populations to determine the selection response

    Effect of cultivar, packaging treatments and temperature on post-harvest quality of okra

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    ABSTRACT    Okra is one of the most popular vegetable crops in Sudan. The introduced cultivars such as Pusa Swani and Clemson Spineless have smooth pods and more adapted to the winter conditions of central Sudan. However, the local cultivar, Khartoumia, has hairy pods and not acceptable in international markets. Okra pods are highly perishable and subject to shriveling especially under the hot arid conditions of central Sudan. Therefore, the objective of this study was to determine the effect of packaging and temperature on the shelf life of okra pods of three introduced cultivars. Treatments consisted of three okra cultivars, namely, Clemson Spineless, Pusa Swani and Mahyco (hybrid); packaging treatments consisted of packing okra pods in cartons lined with intact polyethylene film, perforated polyethylene film or in cartons only and storage temperatures were 140C and 320C. Results showed that pods of the  cultivar Mahyco had the lowest weight loss, retained good colour and had the least decay and rot. Packaging of okra pods in intact or perforated polyethylene film and storing at 140C reduced weight loss and resulted in the best pod colour compared to the control. Packaging in perforated polyethylene film and storing at 140C resulted in the lowest incidence of decay and rot and best overall quality of pods. It is recommended to package okra pods in perforated polyethylene film and ship them to markets at 140C

    Production and characterization of antimicrobial active substance from some macroalgae collected from Abu- Qir bay (Alexandria) Egypt

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    The antimicrobial activity of three different macroalgal species [Jania rubens (Linnaeus) Lamouroux; Ulva fasciata Delile and Sargassum vulgare C. Agardh] belonging to Rhodophyta, Chlorophyta and Phaeophyceae, respectively, were collected seasonally in 2007 to 2008 from Abu-Qir bay (Alexandria, Egypt). The different macroalgal species were tested against pathogenic microbes such as Bacillus subtilis, Staphylococcus aureus and Streptococcus aureus as gram-positive bacteria, Escherichia coli, Salmonella typhi and Klebsiella pneumoniae as gram-negative bacteria and one yeast strain, Candida albicans. The influence of sampling season on the antimicrobial activity of the collected seaweeds showed strong activity in spring followed by winter, summer and autumn, respectively. However, the strongest antimicrobial activity was recorded in 70% acetone extract of U. fasciata collected during winter against all the tested microorganisms. This extract was purified using column chromatography (CC) and thin layer chromatography (TLC). The nature of this purified antimicrobial material was detected using different chemical analysis (UV, IR,1H NMR and MS) which indicated that it is an aromatic compound and has different active groups (-NH2, -C=O, -NO2, phenyl ring and -CH3). The molecular weight of the compound was determined (662) and its structure was characterized as a derivative of phthalate ester [(E)-1-(10-acetamido-2-nitrodec-9-enyl) 2-(10-acetamido-2-nitrodecyl) 4-methylphthalate]. This is the first evidence of the isolation of phthalate esters derivative from green seaweeds (U. fasciata) that has broad antimicrobial activity.Key words: Antimicrobial, pathogenic microbes, season, seaweeds

    Multi-level Multi-objective Quadratic Fractional Programming Problem with Fuzzy Parameters: A FGP Approach

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    The motivation behind this paper is to present multi-level multi-objective quadratic fractional programming (ML-MOQFP) problem with fuzzy parameters in the constraints. ML-MOQFP problem is an important class of non-linear fractional programming problem. These type of problems arise in many fields such as production planning, financial and corporative planning, health care and hospital planning. Firstly, the concept of the -cut and fuzzy partial order relation are applied to transform the set of fuzzy constraints into a common crisp set. Then, the quadratic fractional objective functions in each level are transformed into non-linear objective functions based on a proposed transformation. Secondly, in the proposed model, separate non-linear membership functions for each objective function of the ML-MOQFP problem are defined. Then, the fuzzy goal programming (FGP) approach is utilized to obtain a compromise solution for the ML-MOQFP problem by minimizing the sum of the negative deviational variables. Finally, an illustrative numerical example is given to demonstrate the applicability and performance of the proposed approach

    Acute effects of active isolated stretching on vertical jump performance in active university students

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    The purpose of the study was to determine the acute effects of active isolated stretching on muscular peak power production. Sixty healthy, physically active volunteers (aged 18-28) participated as subjects in this study. Subjects were randomly assigned to two groups; the control group and the experimental group. Subjects performed pre and posttest measures of vertical jump test. The subjects in the control group were asked to perform a certain number of jumps with no stretching routine, while the subjects in the experimental group were asked to perform a set of jumps with active isolated stretching routine. The results calculated for this study did show to have a statistically significant difference in vertical jump performance between subjects who are put through an active isolated stretching regimen and subjects who do not perform any stretching exercises. Results showed that performing active isolated stretching prior to vertical jump performance resulted in significant drop in jumping height.Keywords: Active isolated stretching; vertical jump performance; stretch-shortening cycl

    Effects of nitrogen source and effective micro-organisms on vegetative growth of shrubs of selected grapefruit (Citrus paradisi Macf) cultivars

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       Grapefruit (Citrus Paradisi Macf.) is one of the most important citrus fruits in the Sudan. It can be successfully grown throughout the country where there are suitable soils and sufficient water to sustain tree growth. The objectives of this study were to find out the effects of different nitrogen sources, effective microorganisms (EM) and their combinations on the vegetative growth of shrubs of selected grapefruit cultivars. A field experiment was carried out at Umbarona, Wad Medani, Gezira State, Sudan, latitude 14.38 N, longitude 33.48 E and altitude 409 masl, in June 2012. Treatments consisted of three grapefruit cultivars: Marsh Seedless, Red Blush and Shamber. Fertilizer treatments were urea (100%), chicken manure (100%), urea with chicken manure (50% each), urea with EM, chicken manure with EM, urea (50%)+ chicken manure (50%)+ EM and unfertilized control. All fertilizer treatments were applied at the rate of 43 kg N/ha. Treatments were arranged in a split- plot design with two replicates. Grapefruit cultivars were allotted to the main plots and fertilizer treatments to the sub-plots. Data were collected on plant height (cm), stem diameter (cm), number of new branches, length of new branches (cm) and diameter of new branches (cm). Results showed that Marsh Seedless cultivar had the most vigorous vegetative growth compared to the other two cultivars. The results showed that the combination of urea, chicken manure and EM significantly gave the highest vegetative growth values, followed by chicken manure with EM, urea with chicken manure, urea with EM, urea alone, chicken manure alone and the least values of growth parameters were recorded for the unfertilized control. It is recommended to grow Marsh Seedless grapefruit cultivar and fertilize it with a combination of urea, chicken manure and EM.         يعتبر القريب فروت من أهم ثمار الحمضيات في السودان ويمكن زراعته بنجاح في جميع أنحاء البلاد حيثما توفرت التربة المناسبة والمياه الكافية لنمو الأشجار. أجريت تجربة حقلية في ام بارونة، واد مدنى ولاية الجزيرة، السودان. تهدف هذه التجربة لمعرفة تأثير مصادر النتروجين المختلفة والكائنات الحية الدقيقة الفعالة ومزجها مع بعضها البعض على النمو الخضري لشجيرات أصناف منتخبة من القريب فروت. تضمنت المعاملات ثلاثة أصناف من القريب فروت وهي مارش  ورد بلش وشامبر وسبعة معاملات أسمدة وهي  اليوريا، وزرق الدواجن، يوريا مع زرق الدواجن، يوريا مع الكائنات الحية الدقيقة الفعالة، زرق الدواجن مع الكائنات الحية الدقيقة الفعالة، يوريا مع زرق الدواجن مع الكائنات الحية الدقيقة الفعالة والشاهد. تمت إضافة الأسمدة لكل المعاملات بمعدل 43 كجم نتروجين للهكتار. صممت التجارب بطريقة القطع المنشقة بحيث كانت أصناف القريب فروت هي القطع الرئيسة ومعاملات النتروجين هي القطع الثانوية. جمعت بيانات عن طول النبات (سم) وقطر الساق (سم) وعدد الأفرع الجديدة وطول الفرع (سم) وقطر الفرع (سم). أوضحت النتائج أن الصنف مارش أعطى أعلى نمو خضري مقارنة بالصنفين رد بلش وشامبر. الخليط بين سماد اليوريا وزرق الدواجن و الكائنات الحية الدقيقة الفعالة  أعطت أعلى معدل للنمو الخضري ويليه زرق الدواجن والكائنات الحية الدقيقة الفعالة ثم اليوريا والكائنات الحية الدقيقة الفعالة ثم اليوريا وزرق الدواجن ثم زرق الدواجن لوحده ثم اليوريا لوحده وأدنى معدلات  النمو كانت في الشاهد .  يوصى بزراعة الصنف قريب فروت مارش وتسميده بخليط من اليوريا وزرق الدواجن والكائنات الحية الدقيقة الفعالة
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