224 research outputs found

    Somatic Embryogenesis in Musa Spp.

    Get PDF
    Embryogenesis competent material (scalp) was initiated from shoot tip of Musa spp. cultivar Mas (AA), Berangan (AAA), Intan (AAA), Raja (AAB) and Tanduk (AAB). Somatic embryogenesis were investigated from four explant sources viz., scalps, male flower primordia, in vitro corm slices and immature ovules of Musa acuminata cv. Mas. Scalp formation was optimal on Murashige and Skoog (MS) medium with modified vitamins supplemented with 100 /lM BAP and 1.0 /lM IAA. Among the cultivars investigated, cv. Mas was the most responsive for scalp formation whereby 40% of the shoot tips formed scalps by the 7th month of culture. Cultivar Mas was also the most responsive for meristematic globule formation from scalps attaining 100% meristematic globule formation by week 7 of culture of scalps in Z medium. Cells with embryogenic potential were released from the meristematic globules of cv . Mas after 10 to 12 months of culture of the meristematic globules in Z medium . The embryogenic cell suspension was transferred to liquid S medium and formed globular embryos after 3 to 4 months in culture. Matured globular embryos upon transfer to liquid S regeneration medium supplemented with 0, 1.0, 5.0, 10, 20, 40 and 80 /lM BAP germinated to form roots but without shoots

    日本鶏におけるメラノコルチン1受容体遺伝子(MC1R)多型ならびに同多型が羽装色に及ぼす影響

    Get PDF
    内容の要約広島大学(Hiroshima University)博士(学術)Doctor of Philosophydoctora

    Automatic inductive theorem proving and program construction methods using program transformation

    Get PDF
    We present new approaches to prove universally and existentially quantified conjectures and to construct programs from the resulting proofs. These theorem proving and program construction techniques make use of the distillation algorithm to transform input conjectures into a normalised form which we call distilled form. The proof rules are applied to the resulting distilled program. Our theorem proving and program construction techniques have been implemented in a theorem prover which we call Poitin. We give an overview of the distillation algorithm, and then present the proof and program construction techniques implemented in Poitin. Our implementation of the proof and program construction techniques used in Poitin is then presented. The soundness of the proof technique is shown with respect to a logical proof system using sequent calculus. We show that the constructed programs are correct with respect to their specification. The main contributions of this thesis can be summarised as follows. First, we present fully automatic, and efficient inductive theorem proving techniques. Second, we present a novel program construction technique to construct correct programs. Third, we have shown how automatic program transformation can be used in a novel way in an inductive theorem prover. Finally, the use of distillation to obtain a normal form of the input program reduces over-generalization and generation of non-theorems. We have implemented the theorem prover and demonstrated it on some examples. The use of distillation in the framework of Poitin has eased the automation of the proof and program construction techniques in a reduced search space to make it fully automatic and efficient

    Planning for scanning in construction : optimizing 3D laser scanning operations using building information modelling and a novel specification on surface scanning completeness.

    Get PDF
    Application of Terrestrial Laser Scanning (TLS) technology in the Architectural Engineering and Construction (AEC) industry is gaining popularity because the technology uniquely offers the means to create as-built three-dimensional (3D) models of existing facilities, and conduct construction project progress and dimensional quality measurements. An open challenge with regard to the use TLS for such applications is to efficiently generate effective scanning plans that satisfy pre-defined point cloud quality specifications. Two such specifications are currently commonly used: Level of Accuracy (LOA) that focuses on individual point precision, and Level of Detail (LOD) that focuses on point density. Given such specifications, current practice sees professionals manually prepare scanning plans using existing 2D CAD drawings, some ad-hoc rules (of thumb), and their experience. Yet, it is difficult to manually generate and analyse laser scanning plans to ensure they satisfy scanning quality specifications such as those above. Manually-defined plans may easily lead to over-scanning, or worse under-scanning with incomplete data (which may require the team to go back on site to acquire complementary data). To minimize the risk of producing inadequate scanning plans, some semi-automated and automated methods have been proposed by researchers that use the 3D (BIM) model generated during the design stage. These methods take consideration for LOA and LOD. However, these are point-based specifications that do not guarantee that a sufficient amount of the surface of each object is covered by the acquired data, despite this aspect being important to many of the applications for which TLS is employed (e.g. modelling existing facilities). Therefore, this research uniquely proposes a novel planning for scanning quality specification, called Level of Surface Completeness (LOC) that assesses point cloud quality in terms of surface completeness. In addition, an approach is proposed for automatic planning for scanning in the AEC industry that takes both LOA and LOC specifications into account. The approach is ‘generic’ in the sense that it can be employed for any type of project. It is designed to generate automatic laser scanning plans using as input: (1) the facility’s 3D BIM model; (2) the scanner’s characteristics; and (3) the LOA and LOC specifications. The output is the smallest set of scanning locations necessary to achieve those requirements. The optimal solution is found by formulating the problem as a binary integer programming optimization problem, which is easily solved using a branch-and-cut algorithm. To assess the performance of the approach, experiments are conducted using a simple concrete structural model, a more complex structural model, and a section of the latter extended with Mechanical Electrical and Plumbing (MEP) components. The overall performance of the proposed approach for automatic planning for scanning is encouraging, showing that it is possible to take surface-based specifications into account in automated planning-for-scanning algorithms. However, the experimental results also highlight a significant weakness of the approach presented here which is that it does not take into account the overlapping of surfaces covered from different scanning locations and thus may inaccurately assess covered surfaces

    Crop growth and water-use from saline water tables

    Get PDF
    PhD ThesisHow much water can a crop abstract from below a saline water table and how does the salinity affect yield? These questions are important because shallow groundwater may represent a substantial resource in flat, low-lying areas, but may also represent a threat to sustainability where salinity is high. A series of experiments in a glasshouse aimed to elucidate irrigation management practice under salinity conditions and to develop a root uptake model under both osmotic and matric stresses. The extraction of soil water and groundwater by lettuce and perennial ryegrass crops were measured in three instrumented lysimeters. Water table depths were 0.6,0.9 and 1.2 rn below the soil surface. The lysimeters were initially saturated with saline water (electrical conductivity 4.5 dS m- 1 for lettuce, 9.4 dS m- I for the first crop of ryegrass and 0.4,7.5 & 15.0 dS m-1 for the second crop of ryegrass) and drained until an equilibrium soil water profile was attained. Water with the same electrical conductivity was then supplied by Marione siphons to maintain the constant water table. The water table contribution was recorded and water losses from the soil profile were estimated from daily readings of soil water potential using tensiometersa; nd gypsum blocks. Solute samples were extracted periodically for salinity measurement. The cropping period of lettuce was 90 days from sowing and the lst & 2nd cropping periods of ryegrass were 223 & 215 days respectively. The first ryegrass experiment showed that the water table depth (60,90 and 120 cm) did not have significant contribution (37,36 and 36 mm) on either total soil moisture use or groundwater contribution. Similar results were found for total soil moisture use for lettuce, though the groundwater contribution varied significantly. The second ryegrass experiment showed that salinity at the water table strongly influenced total soil moisture use, but the total groundwater contribution varied only slightly. The overall crop experiments show that the groundwater contribution was within the range of 25-30% of the total water use, except for the 15 dS m7l treatment where the contribution was greater than the soil moisture use. Groundwater contribution rate was higher when the plants were subjected to more osmotic and matric stresses. Yield component data show that increasing salinity leads to a reduction in total yield, but the drymatter proportion was higher. Higher salinities occurred in the upper 15 cm of the root zone, because of the greater soil moisture depletion. Below that depth the salinization rate was smaller, because of the greater groundwater contribution in the later part of the season. There is reasonable agreement between measured and estimated (based on convective transport theory) values soil salinity. Salinities increased in the root zone by about 3-fold of initial salinity for lettuce and around 4-fold for ryegrass in the top 5 cm depth, but below 15 cm depth it was less than 2 fold. Finally, a simplified model was developed to describe the interaction of root-zone salinity and water uptake, considering salinity and water stress as additive. The model shows that the higher the root-zone salinity stress, the higher the predicted water uptake while plant uptake considered -1.5 MPa. This variation is ranged from 4 to 17% for 0.4 to 9.4 dS m-1 and 30 % for 15 dS m-1. The model was developed in a climate with low atmospheric demand, but needs testing in a more severe environment.Bangladesh Agricultural Research Council (BARC) / IDA, World Bank

    Critical Insights in Choosing Approaches to Feedback in Second Language (L2) Writing: Catering Individual Needs

    Get PDF
    Although there is a debate as to whether or not feedback in writing helps second language learners, this research indicates that learners improve in writing with having feedback from their instructors. However, in correcting learners’ errors, especial care should be rendered to learners’ individual needs as all the learners do not like a single approach to feedback. Apart from indicating the importance of feedback, in what this study contributes to the existing literature is the suggestion that learners’ choice of the approaches to feedback varies more because of learners’ ‘individual needs’ than their ‘cultural differences’. Key Words: Writing Errors, Formative Feedback, Summative Feedback, Direct Feedback, Indirect Feedbac

    Design and Implementation of Automated Ankle Foot Orthosis for Foot Drop Patients Using Gait Cycle EMG Analysis

    Get PDF
    Foot drop is known as gait abnormality in which the dropping of the forefoot happens due to the weakness of Tibialis Anterior Muscle for the damage of the common fibular nerve in the anterior portion of the lower leg. In this research, those patients are considered who have foot drop for Guillain–Barré syndrome (GBS). GBS is a peripheral nerve disorder for which bilateral foot drop happens to the patients. So, the aim of this research is to develop an automated Ankle Foot Orthosis (AFO) which will aid the GBS patients in their gait cycle while walking. For the development of this AFO, an EMG analysis has been conducted on both normal people (20 persons, Male 20-45 years) and GBS patients (10 patients, Male 20-45 years) and compared to find out the deviation of the patient’s one from the normal people. The findings of the EMG study show that the stance phase of the gait cycle is not affected by the GBS as correlation coefficient values are in between 0.95 to 1 where the swing phase very much deviates from the normal pattern as the coefficient values are in between 0.6 to 0.7 as well as short swing phase and no heel strike during walking. Considering these, automated AFO has been developed and implemented to test the feasibility and effectiveness on patients. The experimental results show that the effect of GBS on swing phase can be lessened as the value of correlation coefficient increases to 0.85 to 0.9 with long swing phase and proper heel strike on terminal swing phase

    Exploring the potential of non-timber forest products: the case of Ethiopian honey export to Denmark

    Get PDF
    Its diverse agroecology has endowed Ethiopia with enormous honey production potential in Africa. Nevertheless, due to the undeveloped production system and poor market linkage with the global arena, the country could not fetch proportional benefits from this resource. To enhance better understanding on the problem and recommend appropriate improvement measures for the sector, prevailing opportunities and constraints were explored in relation to honey export to Denmark. Major honey stakeholders were contacted to assess the opportunities and constraints of Ethiopian honey export. Semi-structured interview, participatory appraisal technique and short questionnaire interview were adopted for data collection. The results show improving opportunities for exporting companies through creating conducive policy and support from the government of Ethiopia and NGOs. On the other hand, current supply of honey by producers in terms of quantity and quality are major constraints for the exporters. In relation to importer, there are growing demands for Ethiopian honey due to its organic source. Similarly, consumers. survey showed that the demand for organic honey has the highest priority in contrast to origin and price. However, most consumers lack information and have concern over Ethiopian honey; especially in terms of quality and characteristics. Development strategy that improves smallholder honey production capacity, better business communication with potential Danish honey importers and promotion of organic honey to consumers may make a significant contribution to enhance Ethiopian honey export to Denmark.Non-timber Forest Products; Ethiopia; honey; export; markets; Denmark
    corecore