252 research outputs found
Pre-breeding of wheat (Triticum aestivum L.) for Biomass allocation and drought tolerance.
Doctoral Degree. University of KwaZulu-Natal, Pietermaritzburg.Bread wheat (Triticum aestivum L., 2n=6x=42) is the third most important cereal crop globally after maize and rice. However, its production and productivity is affected by recurrent drought and declining soil fertility. Wheat cultivars with a well-balanced biomass allocation and improved root systems have better water- and nutrient-use efficiency and, hence, increased productivity under dry-land farming systems. The overall objective of this study was to develop breeding populations of wheat with enhanced drought tolerance and biomass allocation under water-limited conditions. The specific objectives of the study were: (i) to evaluate agronomic performance and quantify biomass production and allocation between roots and shoots in selected wheat genotypes in response to different soil water levels to select promising genotypes for breeding for drought tolerance and carbon (C) sequestration, (ii) to determine variance components and heritability of biomass allocation and grain yield related traits among 99 genotypes of bread wheat and triticale (Triticosecale Wittmack) to optimize biomass partitioning for drought tolerance, (iii) to deduce the population structure and genome-wide marker-trait association of yield and biomass allocation traits in wheat to facilitate marker-assisted selection for drought tolerance and C sequestration, and (iv) to estimate the combining ability of selected wheat genotypes and their progenies for agronomic traits, biomass allocation and yield under drought-stressed and non-stressed conditions for future breeding and genetic advancement for drought tolerance and C sequestration. To achieve these objectives, different experiments were conducted.
In the first study, 99 wheat genotypes and one triticale accession were evaluated under drought-stressed and non-stressed conditions in the field and greenhouse using a 10Ă—10 alpha lattice design with two replications. Data on the following phenotypic traits were collected: days to heading (DTH), number of productive tillers per plant (NPT), plant height (PH), days to maturity (DTM), spike length (SL), thousand kernel weight (TKW), root and shoot biomass (RB and SB), root to shoot ratio (RS) and grain yield (GY). There was significant (p<0.05) genotypic variation for grain yield and biomass production. The highest grain yield of 247.3 g m-2 was recorded in the genotype LM52 and the least was in genotype Sossognon with 30 g m-2. Shoot biomass ranged from 830g m-2 (genotype Arenza) to 437 g m-2 (LM57), whilst root biomass ranged between 140 g m-2 for LM15 and 603 g m-2 for triticale. Triticale also recorded the highest RS of 1.2, while the least was 0.30 for LM18. Water stress reduced total biomass production by 35% and RS by 14%. Genotypic
variation existed for all measured traits useful for improving drought tolerance, while the calculated RS values can improve accuracy in estimating C sequestration potential of wheat. The following genotypes: BW140, BW141, BW152, BW162, LM26, LM47, LM48, LM71, LM70 and LM75 were selected for further development based on their high grain and biomass production, low drought sensitivity and marked genetic diversity.
In the second study, data obtained from the above experiment were subjected to analyses of variance to calculate variance components, heritability and genetic correlations. Significant (p≤0.05) genetic and environmental variation were observed for all the traits except for spike length. Drought stress decreased the heritability of RS from 47 to 28% and GY from 55 to 17%. The genetic correlations between RS with PH, NPT, SL, SB and GY were weaker under drought-stress (r ≤ - 0.50; p70%) for RS observed in this population constitute several bottlenecks for improving GY and RS simultaneously. However, indirect selection for DTH, PH, RB, and TKW, could help optimize RS and simultaneously improve drought tolerance and yield under drought-stressed condition.
In the third study, the 99 wheat genotypes and one triticale accession were genotyped using 28,356 DArTseq derived single nucleotide polymorphism (SNPs) markers. Phenotypic and genomic data were subjected to genome wide association study (GWAS). Population structure analysis revealed seven clusters with a mean polymorphic information content of 0.42, showing a high degree of diversity. A total of 54 significant marker-trait associations (MTAs) were identified. Twenty-one of the MTAs were detected under drought-stressed condition and 11% were on the genomic loci where quantitative trait loci (QTLs) for GY and RB were previously identified, while the remainder are new events providing information on biomass allocation. There were four genetic markers, two under each water treatment, with pleiotropic genetic effect on RB and SB that may serve as a means for simultaneous selection. Significant MTAs observed in this study will be useful in devising strategies for marker-assisted breeding to improve drought tolerance and to enhance C sequestration capacity of wheat.
Lastly, 10 better performing and genetically diverse wheat genotypes selected during the first experiment were crossed using a half diallel mating design to generate F1 families. The parents and crosses were evaluated using a completely randomized block design with 2 replications under a controlled environment condition. Significant (p<0.05) genotype by water regime interaction effects were recorded for RB, SB, RS and GY. Root and shoot biomass were reduced by 48 and 37%, respectively, due to drought stress hindering biomass allocation patterns and hence C sequestration potential of the tested genotypes. Further, drought stress reduced RS and GY by 18 and 28%, respectively compared with the non-stressed treatment. Analysis of variance showed that both general combining ability (GCA) and specific combining ability (SCA) effects were significant (p<0.05) in conditioning the inheritance of grain yield and related traits and biomass allocation. Non-additive gene effects were more important in controlling the inheritance of the measured traits under drought-stressed and non-stressed conditions. Parental genotypes LM47 and BW140 had significant and positive GCA effects for root and shoot biomass and GY under drought-stressed conditions. These are recommended for recurrent selection programs to improve the respective traits. The crosses BW141Ă—LM48 and LM47Ă—LM75 were good specific combiners for biomass allocation and GY under drought stress, while BW141Ă—LM48 and LM48Ă—LM47 were good combiners under non-stressed condition. These families are selected for advanced breeding to develop pure line cultivars. The preliminary results suggest that simultaneous improvement of grain yield and root biomass can be realized to improve drought tolerance and C sequestration ability in wheat.
Overall, the study detected marked phenotypic and genetic variation among diverse set of wheat genetic resources and candidate crosses for drought tolerance and biomass allocation through field and greenhouse based experiments and genomic analyses. The selected parents and novel crosses are useful for wheat breeding to enhance drought tolerance, yield and yield components and biomass allocation for C sequestration. This is the first study that evaluated biomass allocation in wheat as a strategy to improve drought tolerance and carbon sequestration
Sign language recognition using Kinect sensor based on color stream and skeleton points
This paper presents a sign language recognition system based on color stream and skeleton points. Several approaches have been established to address sign language recognition problems. However, most of the previous approaches still have poor recognition accuracy. The proposed approach uses Kinect sensor based on color stream and skeleton points from the depth stream to improved recognition accuracy. Techniques within this approach use hand trajectories and hand shapes in combating sign recognition challenges. Therefore, for a particular sign a representative feature vector is extracted, which consists of hand trajectories and hand shapes. A sparse dictionary learning algorithm, Label Consistent K-SVD (LC-KSVD) is applied to obtain a discriminative dictionary. Based on that, the system was further developed to a new classification approach for better results. The proposed system was fairly evaluated based on 21 sign words including one-handed signs and two-handed signs. It was observed that the proposed system gets high recognition accuracy of 98.25%, and obtained an average accuracy of 95.34% for signer independent recognition.
Keywords: Sign language, Color stream, Skeleton points, Kinect sensor, Discriminative dictionary
Spatially Coherent RANSAC for Multi-Model Fitting
RANSAC [15, 38, 1] is a reliable method for fitting parametric models to sparse data with many outliers. Originally designed for extracting a single model, RANSAC also has variants for fitting multiple models when supported by data. Our main insight is that, in practice, inliers for each model are often spatially coherent — all previous RANSAC-based methods ignore this. Our new method fits an unspecified number of models to data by combining ideas of random sampling and spatial regularization. As in basic RANSAC, we randomly sample data points to generate a set of proposed models (labels). We formulate model selection and inlier classification as a single problem — labeling of triangulated data points. Geometric fit errors and spatial coherence are combined in one MRF-based energy. In contrast to basic RANSAC, inlier classification does not depend on a fixed threshold. Moreover, our optimization framework allows iterative re-estimation of models/inliers with a clear stopping criteria and convergence guarantees. We show that our new method, SCO- RANSAC, can significantly improve results on synthetic and real data supporting multiple linear, affine, and homographic models
RANCANG BANGUN ALAT PENGUPAS KULIT TELUR PUYUH SEMI OTOMATIS DILENGKAPI DENGAN AUTOWASHER GUNA MENINGKATKAN PRODUKTIVITAS DAN EFEKTIVITAS DALAM PENGUPASAN KULIT TELUR PUYUH
Di Indonesia, telur puyuh rata-rata diolah dengan berbagai bentuk makanan, sehingga membutuhkan proses pengupasan. Lama pengupasan kulit telur puyuh dengan cara manual rata-rata 10 detik/butir, jika dalam jumlah banyak harus diperlukan suatu alat pengupas. Dari permasalahan tersebut penulis membuat “ Alat Pengupaas Kulit Telur Puyuh Semi Otomatis Dilengkapi dengan Autowasher Guna Meningkatkan Produktifitas dan Efektifitas Dalam Pengupasan Kulit Telur Puyuh”. Dalam perencanaan alat pengupas kulit telur puyuh semi otomatis dilengkapi dengan autowasher ini dimulai dari memperhitungkan perencanaan daya motor listrik, perancangan sistem transmisi pada alat, memperhitungkan sabuk V, Pulley, dan diameter Poros. Perhitungan kapasitas produksi berdasarkan putaran screew pengupas berbeban. Berdasarkan perancangan didapatkan spesifikasi alat menggunakan motor listrik ¼ HP 1430 rpm dengan daya 200 watt, diameter poros 20 mm, dengan sistem transmisi menggunakan pulley dengan sabuk V tipe A, kecepatan putar reduser 286 rpm, spinner 62 rpm, screew pengupas 100,5 rpm. kapasitas produksi diperoleh melalui putaran screew pengupas berbeban dengan kecepatan 63 rpm dengan kapasitas produksi 42 kg/h. Kata Kunci: Rancang Bangun, Pengupas Kulit Telur Puyu
Review of current medical literature on root resorption in orthodontics.
Root resorption is a common iatrogenic consequence of orthodontic treatment, although it can also be seen in the absence of orthodontic treatment. It may occur at any time during orthodontic treatment and compromise prognosis of the tooth involved and also the stability of treatment results. Orthodontics is the only branch which actually uses the inflammatory process as a tool for solving esthetic and functional problems. Therefore, every orthodontist should know the risk factors of root resorption involved in the process and plan treatment with an aim to reduce its possibility. The severity and degree of root resorption related with orthodontic treatment are multifactorial, involving environmental factors and host factors. A proper medical history, an assessment of predisposing factors, radiographic evaluation of alterations in root morphology and careful planning and execution of orthodontic mechanics may reduce the incidence of root resorption. The current review is aimed at providing clinicians and academics with an insight into the mechanical and biological aspects in the process of root resorption, the methods of identification during its early stages and intervention at the right time to reduce its severity.Root resorption is a common iatrogenic consequence of orthodontic treatment, although it can also be seen in the absence of orthodontic treatment. It may occur at any time during orthodontic treatment and compromise prognosis of the tooth involved and also the stability of treatment results. Orthodontics is the only branch which actually uses the inflammatory process as a tool for solving esthetic and functional problems. Therefore, every orthodontist should know the risk factors of root resorption involved in the process and plan treatment with an aim to reduce its possibility. The severity and degree of root resorption related with orthodontic treatment are multifactorial, involving environmental factors and host factors. A proper medical history, an assessment of predisposing factors, radiographic evaluation of alterations in root morphology and careful planning and execution of orthodontic mechanics may reduce the incidence of root resorption. The current review is aimed at providing clinicians and academics with an insight into the mechanical and biological aspects in the process of root resorption, the methods of identification during its early stages and intervention at the right time to reduce its severity
Energy Based Multi-Model Fitting and Matching Problems
Feature matching and model fitting are fundamental problems in multi-view geometry. They are chicken-&-egg problems: if models are known it is easier to find matches and vice versa. Standard multi-view geometry techniques sequentially solve feature matching and model fitting as two independent problems after making fairly restrictive assumptions. For example, matching methods rely on strong discriminative power of feature descriptors, which fail for stereo images with repetitive textures or wide baseline. Also, model fitting methods assume given feature matches, which are not known a priori. Moreover, when data supports multiple models the fitting problem becomes challenging even with known matches and current methods commonly use heuristics.
One of the main contributions of this thesis is a joint formulation of fitting and matching problems. We are first to introduce an objective function combining both matching and multi-model estimation. We also propose an approximation algorithm for the corresponding NP-hard optimization problem using block-coordinate descent with respect to matching and model fitting variables. For fixed models, our method uses min-cost-max-flow based algorithm to solve a generalization of a linear assignment problem with label cost (sparsity constraint). Fixed matching case reduces to multi-model fitting subproblem, which is interesting in its own right. In contrast to standard heuristic approaches, we introduce global objective functions for multi-model fitting using various forms of regularization (spatial smoothness and sparsity) and propose a graph-cut based optimization algorithm, PEaRL. Experimental results show that our proposed mathematical formulations and optimization algorithms improve the accuracy and robustness of model estimation over the state-of-the-art in computer vision
Clinical Holistic Medicine: Factors Influencing The Therapeutic Decision-Making. From Academic Knowledge to Emotional Intelligence and Spiritual “Crazy” Wisdom
Scientific holistic medicine is built on holistic medical theory, on therapeutic and ethical principles. The rationale is that the therapist can take the patient into a state of salutogenesis, or existential healing, using his skills and knowledge. But how ever much we want to make therapy a science it remains partly an art, and the more developed the therapist becomes, the more of his/her decisions will be based on intuition, feeling and even inspiration that is more based on love and human concern and other spiritual motivations than on mental reason and rationality in a simple sense of the word. The provocative and paradoxal medieval western concept of the “truth telling clown”, or the eastern concepts of “crazy wisdom” and “holy madness” seems highly relevant here. The problem is how we can ethically justify this kind of highly “irrational” therapeutic behavior in the rational setting of a medical institution. We argue here that holistic therapy has a very high success rate and is doing no harm to the patient, and encourage therapists, psychiatrists, psychologist and other academically trained “helpers” to constantly measure their own success-rate. This paper discusses many of the important factors that influence clinical holistic decision-making. Sexuality could, as many psychoanalysts from Freud to Reich and Searles have believed, be the most healing power that exists and also the most difficult for the mind to comprehend, and thus the most “crazy-wise” tool of therapy
Dholuo Translations and the Complexity of Ambiguity: A Case of Tone in Dholuo Verbal System
The translation of texts from the other languages of the world into Dholuo presents both translators and their audiences/readers with a myriad of complexities in the comprehension of the intended messages. Of notable causes are the availability of multiple options in the translation of particular lexical items in the language(s) of the source text(s) (ST) and those of the target text(s) (TT). This is, notably, caused by the elements of borrowing from the languages of the ST even in instances where there already exist well-grounded lexical items that can serve as equivalents in the languages of the TT. While translators may find this communicatively appropriate, the unconventionality of the usage of such terminologies may actually render the comprehension of the TT difficult to the audience, especially, considering the similarities possibly expressed between the expressions of the ST and those of the TT. The motivation behind such usages of terminologies may imply, though not always, the inadequacy in the TT language usage on the part of the translator and must be of great interest to explore especially to those in the practice and their audiences. The perceived difficulties are furthered by the autosegmental mounting of tone in Dholuo expressions without any orthographic equivalents, making the translators’ work rather difficult and their audiences/readers, sometimes, struggling with the comprehension of the translated texts. This study relies on the contrastive analysis of particular excerpts in English and their translations into Dholuo. It, particularly, explores the place of tone in Dholuo grammar. Key Words: Tone, Text, Source Text, Target Text, Comprehension, Translation, Equivalent
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