These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

[Major domestication traits in Asian rice].  

PubMed

Rice (Oryza sativa L.) is an excellent model plant in elucidation of cereal domestication. Loss of seed shattering, weakened dormancy, and changes in plant architecture were thought to be three key events in the rice domestication and creating the high-yield, uniform-germinating, and densely-planting modern rice. Loss of shattering is considered to be the direct morphological evidence for identifying domesticated rice. Two major shattering QTLs, Sh4 and qSH1, have displayed different domestication histories. Weakened seed dormancy is essential for synchronous germination in agricultural production. Genes Sdr4, qSD7-1, and qSD12 impose a global and complementary adaptation strategies in controlling seed dormancy. The prostate growth habit of wild rice is an adaptation to disturbed habitats, while the erect growth habit of rice cultivars meet the needs of compact planting, and such a plant architecture is mainly controlled by PROG1. The outcrossing habit of wild rice promotes propagation of domestication genes among different populations, while the self-pollinating habit of cultivated rice facilitates fixation of domestication genes. Currently, the researches on rice domestication mainly focus on individual genes or multiple neutral markers, and much less attention has been paid to the evolution of network controlling domestication traits. With the progress in functional genomics research, the molecular mechanism of domestication traits is emerging. Rice domestication researches based on network will be more comprehensive and better reflect rice domestica-tion process. Here, we reviewed most progresses in molecular mechanisms of rice domestication traits, in order to provide the new insights for rice domestication and molecular breeding. PMID:23208135

Ou, Shu-Jun; Wang, Hong-Ru; Chu, Cheng-Cai

2012-11-01

2

Transgenic Bacillus thuringiensis (Bt) Rice Is Safer to Aquatic Ecosystems than Its Non-Transgenic Counterpart  

PubMed Central

Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt) have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt) significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems. PMID:25105299

Li, Guangsheng; Wang, Yongmo; Liu, Biao; Zhang, Guoan

2014-01-01

3

Residues of cyantraniliprole and its metabolite J9Z38 in rice field ecosystem.  

PubMed

A simple and reliable analytical method was developed to detect cyantraniliprole (HGW86) and its metabolite J9Z38 in rice straw, paddy water, brown rice, and paddy soil. The fate of cyantraniliprole and its metabolite J9Z38 in rice field ecosystem was also studied. The target compounds were extracted using acetonitrile, cleaned up on silicagel or strong anion exchange column, and analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The average recoveries of cyantraniliprole and J9Z38 in rice straw, paddy water, brown rice, and paddy soil ranged from 79.0% to 108.6%, with relative standard deviations of 1.1-10.6%. The limits of quantification of cyantraniliprole and J9Z38 were 18 and 39?gkg(-1) for rice straw, 2.8 and 5.0?gkg(-1) for paddy water, 4.3 and 6.3?gkg(-1) for brown rice, and 3.9 and 5.3?gkg(-1) for paddy soil. The trial results showed that the half-lives of cyantraniliprole were 3.2, 4.4, and 6.3d in rice straw and 4.9, 2.0, and 6.2d in paddy water in Zhejiang, Hunan, and Shandong, respectively. The respective final residues of cyantraniliprole and J9Z38 in brown rice were lower than 0.05 and 0.02mgkg(-1) after 14d of pre-harvest interval. The maximum residue limit of cyantraniliprole at 0.1mgkg(-1) and dosage of 100g a.i.hm(-2), which could be considered safe to human beings and animals, were recommended. PMID:23800585

Zhang, Changpeng; Hu, Xiuqing; Zhao, Hua; Wu, Min; He, Hongmei; Zhang, Chunrong; Tang, Tao; Ping, Lifeng; Li, Zhen

2013-09-01

4

Differences in CH4 and N2O emissions between rice nurseries in Chinese major rice cropping areas  

NASA Astrophysics Data System (ADS)

Studies on greenhouse gas (GHG) emissions from paddy field have primarily focused on the post-transplanting period, however, recent researches raise new concerns about GHGs emission from rice nursery. In this study, CH4 and N2O fluxes were determined from different nurseries under major rice cropping systems in China. The tested nurseries included flooded nursery (FN), moist nursery (MN) and dry nursery (DN). Methane emissions from FN were significantly higher than those from MN and DN under all the rice cropping systems. When comparing with FN, MN decreased total CH4 emissions by 74.2%, 72.1% and 49.6% under the rice-upland rotation cropping system (RUR), and the double rice cropping system for the early rice (EDR) and the late rice (LDR), respectively. DN decreased CH4 emissions by 99.2%, 92.0%, 99.0% and 78.6% compared to FN under the single rice cropping system (SR), RUR, EDR and LDR, respectively. When comparing with FN, MN and DN increased N2O emissions by 58.1-134.1% and 28.2-332.7%, respectively. Ultimately, compared with FN across the cropping systems, MN and DN decreased net global warming potentials (GWPs) of CH4 and N2O by 33-68% and 43-86%, respectively. The mitigating effect of MN and DN on total GWPs varied greatly across the systems, ranging from 30.8% in the LDR to 86.5% in the SR. Chinese actual emission from rice nurseries was reduced to 956.66 × 103 t CO2 eq from the theoretical estimate of 2242.59 × 103 t CO2 eq if under the flooded nursery scenario in 2012. Taking into account the large rice nursery area (2032.52 × 103 ha) in China, the results of this study clearly indicate the importance to estimate and mitigate GHGs emission from flooded rice nursery. Being effective to reduce GHG emissions and increase rice yield, dry nursery technique is a promising candidate for climate smart rice cropping.

Zhang, Yi; Li, Zhijie; Feng, Jinfei; Zhang, Xin; Jiang, Yu; Chen, Jin; Zhang, Mingqian; Deng, Aixing; Zhang, Weijian

2014-10-01

5

Identification of major rice allergen and their clinical significance in children  

PubMed Central

Purpose Recently, an increase in the number of patients sensitized to rice allergen with or without clinical symptoms has been reported. This study was designed to determine the major allergens in rice and their clinical significance. Methods Twenty-four children (15 boys and 9 girls; mean age, 16.3 months) with allergic disease, who were sensitized to rice antigen (by UniCAP) in the Pediatric Allergy Respiratory Center at Soonchunhyang University Hospital, were enrolled in this study. The allergenicity of various types of rice (raw, cooked, and heat-treated, simulated gastric fluid [SGF], and simulated intestinal fluid [SIF]) was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoglobulin E (IgE) immunoblots. The patients' medical records, including laboratory data and allergy symptoms after ingestion of rice were reviewed. Results Patients were sensitized to an average of 13.5 food antigens and their mean total IgE was 6,888.7 kU/L. In SDS-PAGE, more than 16 protein bands were observed in the raw rice, whereas only 14-16 kDa and 31-35 kDa protein bands were observed in cooked rice. The common SDS-PAGE protein bands observed in SGF-, SIF-, and heat-treated rice were 9, 14, and 31 kDa. In a heated-rice IgE immunoblot, protein bands of 9, 14, and 31-33 kDa were found in 27.8%, 38.9%, and 38.9% of all sera, respectively, and in 50%, 50%, and 75%, of ser a from the 4 symptomatic patients, respectively. Conclusion The 9-, 14-, and 31-kDa protein bands appeared to be the major allergens responsible for rice allergy symptoms. PMID:22232624

Jeon, You Hoon; Oh, Se Jo; Yang, Hyeon Jong; Lee, Soo Young

2011-01-01

6

Identification of RAPD markers linked to a major blast resistance gene in rice  

Microsoft Academic Search

Rice blast, caused byPyricularia grisea, is a major production constraint in many parts of the world. The Korean rice variety Tongil showed high levels of resistance for about six years when widely planted under highly disease-conducive conditions, before becoming susceptible. Tongil was found to carry a single dominant gene, designatedPi-10t, conferring resistance to isolate 106 of the blast pathogen from

Naweed I. Naqvi; J. Michael Bonman; David J. Mackill; Rebecca J. Nelson; Bharat B. Chattoo

1995-01-01

7

Major Ecosystems in China: Dynamics and Challenges for Sustainable Management  

NASA Astrophysics Data System (ADS)

Ecosystems, though impacted by global environmental change, can also contribute to the adaptation and mitigation of such large scale changes. Therefore, sustainable ecosystem management is crucial in reaching a sustainable future for the biosphere. Based on the published literature and publicly accessible data, this paper discussed the status and trends of forest, grassland, and wetland ecosystems in China that play important roles in the ecological integrity and human welfare of the nation. Ecological degradation has been observed in these ecosystems at various levels and geographic locations. Biophysical (e.g., climate change) and socioeconomic factors (e.g., intensive human use) are the main reasons for ecosystem degradation with the latter factors serving as the dominant driving forces. The three broad categories of ecosystems in China have partially recovered from degradation thanks to large scale ecological restoration projects implemented in the last few decades. China, as the largest and most populated developing nation, still faces huge challenges regarding ecosystem management in a changing and globalizing world. To further improve ecosystem management in China, four recommendations were proposed, including: (1) advance ecosystem management towards an application-oriented, multidisciplinary science; (2) establish a well-functioning national ecological monitoring and data sharing mechanism; (3) develop impact and effectiveness assessment approaches for policies, plans, and ecological restoration projects; and (4) promote legal and institutional innovations to balance the intrinsic needs of ecological and socioeconomic systems. Any change in China's ecosystem management approach towards a more sustainable one will benefit the whole world. Therefore, international collaborations on ecological and environmental issues need to be expanded.

Lü, Yihe; Fu, Bojie; Wei, Wei; Yu, Xiubo; Sun, Ranhao

2011-07-01

8

Major QTLs Control Resistance to Rice Hoja Blanca Virus and Its Vector Tagosodes orizicolus  

PubMed Central

Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

Romero, Luz E.; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J.; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C.; Martinez, Cesar P.; Calvert, Lee; Lorieux, Mathias

2013-01-01

9

Major QTLs control resistance to rice hoja blanca virus and its vector Tagosodes orizicolus.  

PubMed

Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

Romero, Luz E; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C; Martinez, César P; Calvert, Lee; Lorieux, Mathias

2014-01-01

10

Days to heading 7, a major quantitative locus determining photoperiod sensitivity and regional adaptation in rice.  

PubMed

Success of modern agriculture relies heavily on breeding of crops with maximal regional adaptability and yield potentials. A major limiting factor for crop cultivation is their flowering time, which is strongly regulated by day length (photoperiod) and temperature. Here we report identification and characterization of Days to heading 7 (DTH7), a major genetic locus underlying photoperiod sensitivity and grain yield in rice. Map-based cloning reveals that DTH7 encodes a pseudo-response regulator protein and its expression is regulated by photoperiod. We show that in long days DTH7 acts downstream of the photoreceptor phytochrome B to repress the expression of Ehd1, an up-regulator of the "florigen" genes (Hd3a and RFT1), leading to delayed flowering. Further, we find that haplotype combinations of DTH7 with Grain number, plant height, and heading date 7 (Ghd7) and DTH8 correlate well with the heading date and grain yield of rice under different photoperiod conditions. Our data provide not only a macroscopic view of the genetic control of photoperiod sensitivity in rice but also a foundation for breeding of rice cultivars better adapted to the target environments using rational design. PMID:25378698

Gao, He; Jin, Mingna; Zheng, Xiao-Ming; Chen, Jun; Yuan, Dingyang; Xin, Yeyun; Wang, Maoqing; Huang, Dongyi; Zhang, Zhe; Zhou, Kunneng; Sheng, Peike; Ma, Jin; Ma, Weiwei; Deng, Huafeng; Jiang, Ling; Liu, Shijia; Wang, Haiyang; Wu, Chuanyin; Yuan, Longping; Wan, Jianmin

2014-11-18

11

LETTER Herbivory makes major contributions to ecosystem carbon and nutrient cycling in tropical forests  

E-print Network

, ecosystem biogeochemistry, net primary productivity, nitrogen cycle, plant­soil feedbacks, soil phosphorus by influencing cycles of C, nitrogen (N) and phosphorus (P) (Huntly 1991; Feeley & Terborgh 2005LETTER Herbivory makes major contributions to ecosystem carbon and nutrient cycling in tropical

Malhi, Yadvinder

12

Marine viruses--major players in the global ecosystem.  

PubMed

Viruses are by far the most abundant 'lifeforms' in the oceans and are the reservoir of most of the genetic diversity in the sea. The estimated 10(30) viruses in the ocean, if stretched end to end, would span farther than the nearest 60 galaxies. Every second, approximately 10(23) viral infections occur in the ocean. These infections are a major source of mortality, and cause disease in a range of organisms, from shrimp to whales. As a result, viruses influence the composition of marine communities and are a major force behind biogeochemical cycles. Each infection has the potential to introduce new genetic information into an organism or progeny virus, thereby driving the evolution of both host and viral assemblages. Probing this vast reservoir of genetic and biological diversity continues to yield exciting discoveries. PMID:17853907

Suttle, Curtis A

2007-10-01

13

Agriculture, Ecosystems and Environment 95 (2003) 289296 Effects of foraging waterfowl in winter flooded rice fields  

E-print Network

flooded rice fields on weed stress and residue decomposition J.W. van Groenigena,, E.G. Burnsb, J quantifies the agronomic benefits of foraging waterfowl in winter flooded rice fields in the Sacramento Valley of California (US). Fifteen winter flooded rice fields along a 105 km long transect, each

van Kessel, Chris

14

Nramp5 is a major transporter responsible for manganese and cadmium uptake in rice.  

PubMed

Paddy rice (Oryza sativa) is able to accumulate high concentrations of Mn without showing toxicity; however, the molecular mechanisms underlying Mn uptake are unknown. Here, we report that a member of the Nramp (for the Natural Resistance-Associated Macrophage Protein) family, Nramp5, is involved in Mn uptake and subsequently the accumulation of high concentrations of Mn in rice. Nramp5 was constitutively expressed in the roots and encodes a plasma membrane-localized protein. Nramp5 was polarly localized at the distal side of both exodermis and endodermis cells. Knockout of Nramp5 resulted in a significant reduction in growth and grain yield, especially when grown at low Mn concentrations. This growth reduction could be partially rescued by supplying high concentrations of Mn but not by the addition of Fe. Mineral analysis showed that the concentration of Mn and Cd in both the roots and shoots was lower in the knockout line than in wild-type rice. A short-term uptake experiment revealed that the knockout line lost the ability to take up Mn and Cd. Taken together, Nramp5 is a major transporter of Mn and Cd and is responsible for the transport of Mn and Cd from the external solution to root cells. PMID:22589467

Sasaki, Akimasa; Yamaji, Naoki; Yokosho, Kengo; Ma, Jian Feng

2012-05-01

15

Arsenic concentrations in paddy soil and rice and health implications for major rice-growing regions of Cambodia.  

PubMed

Despite the global importance of As in rice, research has primarily focused on Bangladesh, India, China, and the United States with limited attention given to other countries. Owing to both indigenous As within the soil and the possible increases arising from the onset of irrigation with groundwater, an assessment of As in rice within Cambodia is needed, which offers a "base-case" comparison against sediments of similar origin that comprise rice paddy soils where As-contaminated water is used for irrigation (e.g., Bangladesh). Here, we evaluated the As content of rice from five provinces (Kandal, Prey Veng, Battambang, Banteay Meanchey, and Kampong Thom) in the rice-growing regions of Cambodia and coupled that data to soil-chemical factors based on extractions of paddy soil collected and processed under anoxic conditions. At total soil As concentrations ranging 0.8 to 18 ?g g(-1), total grain As concentrations averaged 0.2 ?g g(-1) and ranged from 0.1 to 0.37 with Banteay Meanchey rice having significantly higher values than Prey Veng rice. Overall, soil-extractable concentrations of As, Fe, P, and Si and total As were poor predictors of grain As concentrations. While biogeochemical factors leading to reduction of As(V)-bearing Fe(III) oxides are likely most important for predicting plant-available As, husk and straw As concentrations were the most significant predictors of grain-As levels among our measured parameters. PMID:24712677

Seyfferth, Angelia L; McCurdy, Sarah; Schaefer, Michael V; Fendorf, Scott

2014-05-01

16

[Controlling effects of multiple species coexistence on rice diseases, pests and weeds in paddy field ecosystem].  

PubMed

Establishing a species-diversified cropping system to control crop diseases, insect pests and weeds is an important approach to sustainable agricultural development. This paper reviewed the researches on paddy field species-diversified cropping systems at home and abroad, and discussed the controlling effects and mechanisms of multiple species coexistence on rice diseases, pests and weeds control. The multiple species coexistence models such as rice-fish, rice-duck, rice-azolla-fish and rice-azolla-duck had effective controlling effects on Thanatephorus cucumeris (Frank) Donk, Nilaparata lugens Stal, Chaphalocrocis medinalis Gueneeand, and weeds. Other models like intercropping rice with Zizania caduciflora L. and with other wetland crops also had effective effects in controlling the occurrence and spread of Pyricularia grisea. It was suggested that further studies should be strengthened from the viewpoints of crop culture, molecular biology, and chemical ecolo- PMID:17650871

Wang, Han; Tang, Jian-jun; Xie, Jian; Chen, Xin

2007-05-01

17

Rice is the staple food source of nutrients for both humans and livestock throughout the world. The major proteins in rice seeds  

E-print Network

control, but protein content is too low. Rice is a major staple food source and as a source of dietary-I (3, 4, 5). On the other hand, glutelin makes up 60-80% of the protein content in endosperm (6, 2, 7 in their active GTP fixed form (10). Through their effectors, Rab GTPases regulate vesicle formation, actin

Collins, Gary S.

18

Diversity of Gram negative bacteria antagonistic against major pathogens of rice from rice seed in the tropic environment.  

PubMed

With the use of a seed washing technique, more than 4000 Gram negative bacteria were isolated by two improved isolation methods from 446 batches of 1 kg rice seed samples obtained from 22 provinces in the Philippines. They were initially characterized on the basis of colony morphology and results of biochemical and pathogenicity tests. Six hundred and fifty-two strains were further identified by Biolog, from which 133 were selected for fatty acid methylester (FAME) analysis together with 80 standard reference strains. Sixteen species or types of Pseudomonas and 17 genera of non-pseudomonads were identified, more than one third of which have not been recorded in rice. The most predominant species observed were P.putida and P. fulva. About 17% of the strains of Pseudomonas and 2% of the non pseudomonads were antagonistic to one or more fungal or bacterial pathogens of rice. Rice seed is an important source of biological control agents. PMID:12861624

Xie, Guan-Lin; Soad, Algam; Swings, J; Mew, T W

2003-01-01

19

Assessment of toxicity risk of insecticides used in rice ecosystem on Trichogramma japonicum, an egg parasitoid of rice lepidopterans.  

PubMed

Both chemical and biological methods are essential for control of insects, for example, lepidopterans, on rice. Thus, it is important to know the effect of chemicals on the biological control agents. In this study, we assessed the toxicity of commonly used insecticides on a biological control agent, Trichogramma japonicum Ahmead (an egg parasitoid of rice lepidopterans) by using a dry film residue method. Results showed that thirty insecticides from seven chemical classes exhibited various degree of toxicity to this parasitoid. Among the seven classes of chemicals tested, organophosphates (chlorpyrifos, fenitrothion, phoxim, profenofos, and triazophos) and carbamates (carbaryl, carbsulfan, isoprocarb, metolcarb, and promecarb) exhibited the highest intrinsic toxicity to T. japponicum, with an LC50 of 0.035 (0.029-0.044) to 0.49 (0.34-0.87) mg active ingredient (a.i.) L(-1), followed by antibiotics (abamectin, emamectin benzoate, and ivermectin), phenylpyrazoles (butane-fipronil, ethiprole, and fipronil), pyrethroids (cyhalthrin, cypermethrin, fenpropathrin, and lambda-cyhaothrin), and neonicotinoids (acetamiprid, imidacloprid, imidaclothiz, nitenpyram, thiacloprid, and thiamethoxam). Moreover, the insect growth regulator insecticides (chlorfluazuron, fufenozide, hexaflumuron and tebufenozide) exhibited the lowest toxicity to the wasps with an LC50 of 3,383 (2406-5499) to 30206 (23107-41008) mg ai. L(-1). Risk quotient analysis showed that phenylpyrazoles, pyrethroids, insect growth regulators, neonicotinoids (with the exception of thiamethoxam), and antibiotics (with the exception of abamectin) are classified as safe agents to the parasitoid, while organophosphates and carbamates are classified as slightly, moderately, or highly toxic agents to the parasitoid. The data presented in this paper provided useful information on the selection of compatible insecticides with T. japonicum. PMID:22420260

Zhao, Xueping; Wu, Changxing; Wang, Yanhua; Cang, Tao; Chen, Liping; Yu, Ruixian; Wang, Qiang

2012-02-01

20

Two alanine aminotranferases link mitochondrial glycolate oxidation to the major photorespiratory pathway in Arabidopsis and rice.  

PubMed

The major photorespiratory pathway in higher plants is distributed over chloroplasts, mitochondria, and peroxisomes. In this pathway, glycolate oxidation takes place in peroxisomes. It was previously suggested that a mitochondrial glycolate dehydrogenase (GlcDH) that was conserved from green algae lacking leaf-type peroxisomes contributes to photorespiration in Arabidopsis thaliana. Here, the identification of two Arabidopsis mitochondrial alanine:glyoxylate aminotransferases (ALAATs) that link glycolate oxidation to glycine formation are described. By this reaction, the mitochondrial side pathway produces glycine from glyoxylate that can be used in the glycine decarboxylase (GCD) reaction of the major pathway. RNA interference (RNAi) suppression of mitochondrial ALAAT did not result in major changes in metabolite pools under standard conditions or enhanced photorespiratroy flux, respectively. However, RNAi lines showed reduced photorespiratory CO(2) release and a lower CO(2) compensation point. Mitochondria isolated from RNAi lines are incapable of converting glycolate to CO(2), whereas simultaneous overexpression of GlcDH and ALAATs in transiently transformed tobacco leaves enhances glycolate conversion. Furthermore, analyses of rice mitochondria suggest that the side pathway for glycolate oxidation and glycine formation is conserved in monocotyledoneous plants. It is concluded that the photorespiratory pathway from green algae has been functionally conserved in higher plants. PMID:22268146

Niessen, Markus; Krause, Katrin; Horst, Ina; Staebler, Norma; Klaus, Stephanie; Gaertner, Stefanie; Kebeish, Rashad; Araujo, Wagner L; Fernie, Alisdair R; Peterhansel, Christoph

2012-04-01

21

Identification and characterization of the major mitochondrial Fe transporter in rice  

PubMed Central

The uptake, translocation and compartmentalization of Fe are essential for plant cell function and life cycle. Despite rapid progress in our understanding of Fe homeostasis in plants, Fe transport from the cytoplasm to mitochondria was, until recently, poorly understood. The screening of 3,993 mutant lines for symptoms of Fe deficiency resulted in the identification and characterization of a major mitochondrial Fe transporter (MIT) in rice. MIT was found to localize to mitochondria and to complement the growth of a yeast strain defective in mitochondrial Fe transport. The knockout of MIT resulted in a lethal phenotype, and in knock-down plants, several agronomic characteristics were compromised, such as plant height, average number of tillers, days to flower, fertility and yield. Changes in the expression of genes involved in Fe transport suggested a disturbance of cellular Fe transport. Furthermore, the mitochondrial Fe concentration and the activity of the mitochondrial Fe-S enzyme aconitase were significantly reduced compared with wild-type plants. The identification of MIT is a significant advance in the field of plant Fe nutrition and should facilitate the cloning of paralogs from other plant species. PMID:21921696

Bashir, Khurram; Ishimaru, Yasuhiro

2011-01-01

22

Herbivory makes major contributions to ecosystem carbon and nutrient cycling in tropical forests.  

PubMed

The functional role of herbivores in tropical rainforests remains poorly understood. We quantified the magnitude of, and underlying controls on, carbon, nitrogen and phosphorus cycled by invertebrate herbivory along a 2800 m elevational gradient in the tropical Andes spanning 12°C mean annual temperature. We find, firstly, that leaf area loss is greater at warmer sites with lower foliar phosphorus, and secondly, that the estimated herbivore-mediated flux of foliar nitrogen and phosphorus from plants to soil via leaf area loss is similar to, or greater than, other major sources of these nutrients in tropical forests. Finally, we estimate that herbivores consume a significant portion of plant carbon, potentially causing major shifts in the pattern of plant and soil carbon cycling. We conclude that future shifts in herbivore abundance and activity as a result of environmental change could have major impacts on soil fertility and ecosystem carbon sequestration in tropical forests. PMID:24372865

Metcalfe, Daniel B; Asner, Gregory P; Martin, Roberta E; Silva Espejo, Javier E; Huasco, Walter Huaraca; Farfán Amézquita, Felix F; Carranza-Jimenez, Loreli; Galiano Cabrera, Darcy F; Baca, Liliana Durand; Sinca, Felipe; Huaraca Quispe, Lidia P; Taype, Ivonne Alzamora; Mora, Luzmila Eguiluz; Dávila, Angela Rozas; Solórzano, Marlene Mamani; Puma Vilca, Beisit L; Laupa Román, Judith M; Guerra Bustios, Patricia C; Revilla, Norma Salinas; Tupayachi, Raul; Girardin, Cécile A J; Doughty, Christopher E; Malhi, Yadvinder

2014-03-01

23

Assessing Major Ecosystem Types and the Challenge of Sustainability in Turkey  

NASA Astrophysics Data System (ADS)

In recent years, Turkey has experienced rapid economic and population growth coupled with both an equally rapid increase in energy consumption and a vast disparity in welfare between socioeconomic groups and regions. In turn, these pressures have accelerated the destruction of productive, assimilative, and regenerative capacities of the ecosystems, which are essential for the well-being of the people and the economy. This paper describes the structure and function of major ecosystem types in Turkey and discusses the underlying causes of environmental degradation in the framework of economy, energy, environment, and ethics. From a national perspective, this paper suggests three sustainability-based policies necessary for Turkey's long-term interests that balance economic, environmental, and energy goals: (1) decoupling economic growth from energy consumption growth through the development of energy-efficient and renewable energy technologies; (2) linking economic efficiency and distributive justice of wealth and power through distributive and participatory public policies; and (3) integrating the economic and ecological systems through the internalization of externalities and ecosystem rehabilitation.

Evrendilek, Fatih; Doygun, Hakan

2000-11-01

24

Development of pyramidal lines with two major QTLs conferring resistance to sheath blight in rice (Oryza sativa L.)  

NASA Astrophysics Data System (ADS)

Sheath blight is an emerging threat in rice cultivation. It is animportant disease caused by the soil-borne necrotrophic pathogenic fungus, Rhizoctonia solani Kühn. However, to date neither known major genes for quantitative resistance, nor any rice lines immune to this disease has been identified. The disease resistance is quantitative in nature. Numerous genes are involved in this resistance process. There are few quantitative trait loci (QTLs) detected conferring improved resistance against the disease. Teqing and Tetepshowimproved resistance having QTLs, qSB-9 and qSBR11-1, respectively. Since, these QTLs demonstrates additive effects, pyramiding of these QTLs might be an option to increase the sheath blight resistance in rice. Nine rice cultivars were screened at greenhouse conditions. Results showed that Tetep and Teqing had the lowest disease ratings. UKMRC2a new high yielding cultivar was as recipient parent. Crosses between UKMRC2 and Teqing, and UKMRC2 and Tetep were made and confirmed. Subsequently 4-way crosses between the two F1s were performed to develop pyramidal lines.

Hossain, Md Kamal; Jena, Kshirod; Bhuiyan, Md Atiqur Rahman; Ratnam, Wickneswari

2014-09-01

25

Dro1, a major QTL involved in deep rooting of rice under upland field conditions.  

PubMed

Developing a deep root system is an important strategy for avoiding drought stress in rice. Using the 'basket' method, the ratio of deep rooting (RDR; the proportion of total roots that elongated through the basket bottom) was calculated to evaluate deep rooting. A new major quantitative trait locus (QTL) controlling RDR was detected on chromosome 9 by using 117 recombinant inbred lines (RILs) derived from a cross between the lowland cultivar IR64, with shallow rooting, and the upland cultivar Kinandang Patong (KP), with deep rooting. This QTL explained 66.6% of the total phenotypic variance in RDR in the RILs. A BC(2)F(3) line homozygous for the KP allele of the QTL had an RDR of 40.4%, compared with 2.6% for the homozygous IR64 allele. Fine mapping of this QTL was undertaken using eight BC(2)F(3) recombinant lines. The RDR QTL Dro1 (Deeper rooting 1) was mapped between the markers RM24393 and RM7424, which delimit a 608.4 kb interval in the reference cultivar Nipponbare. To clarify the influence of Dro1 in an upland field, the root distribution in different soil layers was quantified by means of core sampling. A line homozygous for the KP allele of Dro1 (Dro1-KP) and IR64 did not differ in root dry weight in the shallow soil layers (0-25 cm), but root dry weight of Dro1-KP in deep soil layers (25-50 cm) was significantly greater than that of IR64, suggesting that Dro1 plays a crucial role in increased deep rooting under upland field conditions. PMID:21212298

Uga, Yusaku; Okuno, Kazutoshi; Yano, Masahiro

2011-05-01

26

Earthworms change the abundance and community structure of nematodes and protozoa in a maize residue amended rice–wheat rotation agro-ecosystem  

Microsoft Academic Search

The influence of earthworms on nematodes and protozoan communities was determined during the wheat phase of a six year rice–wheat rotation agro-ecosystem. Experimental plots in the rotation had five treatments, i.e. incorporation or mulching of maize residues with or without added earthworms and a control. The addition of maize residues to soil strongly affected the abundance and community structure of

Jun Tao; Xiaoyun Chen; Manqiang Liu; Feng Hu; Bryan Griffiths; Huixin Li

2009-01-01

27

Molecular Genetic Diversity of Major Indian Rice Cultivars over Decadal Periods  

PubMed Central

Genetic diversity in representative sets of high yielding varieties of rice released in India between 1970 and 2010 was studied at molecular level employing hypervariable microsatellite markers. Of 64 rice SSR primer pairs studied, 52 showed polymorphism, when screened in 100 rice genotypes. A total of 184 alleles was identified averaging 3.63 alleles per locus. Cluster analysis clearly grouped the 100 genotypes into their respective decadal periods i.e., 1970s, 1980s, 1990s and 2000s. The trend of diversity over the decadal periods estimated based on the number of alleles (Na), allelic richness (Rs), Nei’s genetic diversity index (He), observed heterozygosity (Ho) and polymorphism information content (PIC) revealed increase of diversity over the periods in year of releasewise and longevitywise classification of rice varieties. Analysis of molecular variance (AMOVA) suggested more variation in within the decadal periods than among the decades. Pairwise comparison of population differentiation (Fst) among decadal periods showed significant difference between all the pairs except a few. Analysis of trends of appearing and disappearing alleles over decadal periods showed an increase in the appearance of alleles and decrease in disappearance in both the categories of varieties. It was obvious from the present findings, that genetic diversity was progressively on the rise in the varieties released during the decadal periods, between 1970s and 2000s. PMID:23805204

Deborah, Dondapati Annekitty; Vipparla, Abhilash; Anuradha, Ghanta; Siddiq, Ebrahimali Abubacker; Vemireddy, Lakshminarayana Reddy

2013-01-01

28

Constitutive expression of a cowpea trypsin inhibitor gene, CpTi , in transgenic rice plants confers resistance to two major rice insect pests  

Microsoft Academic Search

The gene encoding a cowpea trypsin inhibitor (CpTI), which confers insect resistance in trangenic tobacco, was introduced into rice. Expression of the CpTi gene driven by the constitutively active promoter of the rice actin 1 gene (Act1) leads to high-level accumulation of the CpTI protein in transgenic rice plants. Protein extracts from transgenic rice plants exhibit a strong inhibitory activity

Deping Xu; Qingzhong Xue; David McElroy; Yogesh Mawal; Vaughan A. Hilder; Ray Wu

1996-01-01

29

Ecosystems  

NSDL National Science Digital Library

This self-contained module on ecosystems includes a range of fun activities that students can perform in the classroom and at home with family members. They impart important concepts such as observation, identification, measurement, and differentiation.

Science, Houghton M.

30

Mutation of a major CG methylase in rice causes genome-wide hypomethylation, dysregulated genome expression, and seedling lethality.  

PubMed

Cytosine methylation at CG sites ((m)CG) plays critical roles in development, epigenetic inheritance, and genome stability in mammals and plants. In the dicot model plant Arabidopsis thaliana, methyltransferase 1 (MET1), a principal CG methylase, functions to maintain (m)CG during DNA replication, with its null mutation resulting in global hypomethylation and pleiotropic developmental defects. Null mutation of a critical CG methylase has not been characterized at a whole-genome level in other higher eukaryotes, leaving the generality of the Arabidopsis findings largely speculative. Rice is a model plant of monocots, to which many of our important crops belong. Here we have characterized a null mutant of OsMet1-2, the major CG methylase in rice. We found that seeds homozygous for OsMet1-2 gene mutation (OsMET1-2(-/-)), which directly segregated from normal heterozygote plants (OsMET1-2(+/-)), were seriously maldeveloped, and all germinated seedlings underwent swift necrotic death. Compared with wild type, genome-wide loss of (m)CG occurred in the mutant methylome, which was accompanied by a plethora of quantitative molecular phenotypes including dysregulated expression of diverse protein-coding genes, activation and repression of transposable elements, and altered small RNA profiles. Our results have revealed conservation but also distinct functional differences in CG methylases between rice and Arabidopsis. PMID:25002488

Hu, Lanjuan; Li, Ning; Xu, Chunming; Zhong, Silin; Lin, Xiuyun; Yang, Jingjing; Zhou, Tianqi; Yuliang, Anzhi; Wu, Ying; Chen, Yun-Ru; Cao, Xiaofeng; Zemach, Assaf; Rustgi, Sachin; von Wettstein, Diter; Liu, Bao

2014-07-22

31

Nramp5 Is a Major Transporter Responsible for Manganese and Cadmium Uptake in Rice[C][W  

PubMed Central

Paddy rice (Oryza sativa) is able to accumulate high concentrations of Mn without showing toxicity; however, the molecular mechanisms underlying Mn uptake are unknown. Here, we report that a member of the Nramp (for the Natural Resistance-Associated Macrophage Protein) family, Nramp5, is involved in Mn uptake and subsequently the accumulation of high concentrations of Mn in rice. Nramp5 was constitutively expressed in the roots and encodes a plasma membrane–localized protein. Nramp5 was polarly localized at the distal side of both exodermis and endodermis cells. Knockout of Nramp5 resulted in a significant reduction in growth and grain yield, especially when grown at low Mn concentrations. This growth reduction could be partially rescued by supplying high concentrations of Mn but not by the addition of Fe. Mineral analysis showed that the concentration of Mn and Cd in both the roots and shoots was lower in the knockout line than in wild-type rice. A short-term uptake experiment revealed that the knockout line lost the ability to take up Mn and Cd. Taken together, Nramp5 is a major transporter of Mn and Cd and is responsible for the transport of Mn and Cd from the external solution to root cells. PMID:22589467

Sasaki, Akimasa; Yamaji, Naoki; Yokosho, Kengo; Ma, Jian Feng

2012-01-01

32

Soil organic carbon (SOC) is an indicator of ecosystem quality and plays a major role in the biogeochemical cycles of major  

E-print Network

), directly influences the physical, chemical, and biological properties and processes in the soil. Carbon, the stabilization of soil aggregates and structure, and the regulation of microbial activity, ultimately affecting923 Soil organic carbon (SOC) is an indicator of ecosystem quality and plays a major role

Grunwald, Sabine

33

OsNRAMP5, a major player for constitutive iron and manganese uptake in rice.  

PubMed

Manganese (Mn) and iron (Fe) are essential mineral micronutrients for plants and their deficiency and or toxicity represents a serious agricultural problem. In rice the information about genes involved in Mn uptake from soil is scarce. Recently, we showed that OsNRAMP5 is a plasma membrane protein involved in Mn and Fe transport. The concentration of Mn in roots, shoots and xylem sap of OsNRAMP5 RNAi (OsNRAMP5i) plants was significantly reduced compared with WT plants. The expression of OsNRAMP5 is not controlled by Fe deficiency in root and was also observed in pistil, ovary, lemma and palea. These data show that rice would utilize OsNRAMP5 for constitutive Fe and Mn uptake, while OsNRAMP5 would also play a role in Fe and Mn transport during flowering and seed development. PMID:22751306

Ishimaru, Yasuhiro; Bashir, Khurram; Nakanishi, Hiromi; Nishizawa, Naoko K

2012-07-01

34

Ecosystems  

NSDL National Science Digital Library

This "Ecosystems" module has four units of instruction. The units include: natural selection, population balance, exchange cycles, and environmental protection. Each module has a "Hazards" link that leads to a menu of study units on various environmental hazards (such as oil spills, farm runoff, insecticides, and so on).

Klemm, W. R.

2002-01-01

35

A process-based model of N2O emission from a rice-winter wheat rotation agro-ecosystem: Structure, validation and sensitivity  

NASA Astrophysics Data System (ADS)

In order to numerically simulate daily nitrous oxide (N2O) emission from a rice-winter wheat rotation cropping system, a process-based site model was developed (referred to as IAP-N-GAS) to track the movement and transformation of several forms of nitrogen in the agro-ecosystem, which is affected by climate, soil, crop growth and management practices. The simulation of daily N2O fluxes, along with key daily environmental variables, was validated with three-year observations conducted in East China. The validation demonstrated that the model simulated well daily solar radiation, soil temperature and moisture, and also captured the dynamics and magnitude of accumulated rice aboveground biomass and mineral nitrogen in the soil. The simulated daily N2O emissions over all three years investigated were generally in good agreement with field observations. Particularly well simulated were the peak N2O emissions induced by fertilizations, rainfall events or mid-season drainages. The model simulation also represented closely the inter-annual variation in N2O emission. These validations imply that the model has the capability to capture the general characteristics of N2O emission from a typical rice-wheat rotation agro-ecosystem. Sensitivity analyses revealed that the simulated N2O emission is most sensitive to the fertilizer application rate and the soil organic matter content, but it is much less sensitive to variations in soil pH and texture, temperature, precipitation and crop residue incorporation rate under local conditions.

Zhou, Zaixing; Zheng, Xunhua; Xie, Baohua; Han, Shenghui; Liu, Chunyan

2010-01-01

36

MucoRice-cholera toxin B-subunit, a rice-based oral cholera vaccine, down-regulates the expression of ?-amylase/trypsin inhibitor-like protein family as major rice allergens.  

PubMed

To develop a cold chain- and needle/syringe-free rice-based cholera vaccine (MucoRice-CTB) for human use, we previously advanced the MucoRice system by introducing antisense genes specific for endogenous rice storage proteins and produced a molecularly uniform, human-applicable, high-yield MucoRice-CTB devoid of plant-associated sugar. To maintain the cold chain-free property of this vaccine for clinical application, we wanted to use a polished rice powder preparation of MucoRice-CTB without further purification but wondered whether this might cause an unexpected increase in rice allergen protein expression levels in MucoRice-CTB and prompt safety concerns. Therefore, we used two-dimensional fluorescence difference gel electrophoresis and shotgun MS/MS proteomics to compare rice allergen protein expression levels in MucoRice-CTB and wild-type (WT) rice. Both proteomics analyses showed that the only notable change in the expression levels of rice allergen protein in MucoRice-CTB, compared with those in WT rice, was a decrease in the expression levels of ?-amylase/trypsin inhibitor-like protein family such as the seed allergen protein RAG2. Real-time PCR analysis showed mRNA of RAG2 reduced in MucoRice-CTB seed. These results demonstrate that no known rice allergens appear to be up-reregulated by genetic modification of MucoRice-CTB, suggesting that MucoRice-CTB has potential as a safe oral cholera vaccine for clinical application. PMID:23763241

Kurokawa, Shiho; Nakamura, Rika; Mejima, Mio; Kozuka-Hata, Hiroko; Kuroda, Masaharu; Takeyama, Natsumi; Oyama, Masaaki; Satoh, Shigeru; Kiyono, Hiroshi; Masumura, Takehiro; Teshima, Reiko; Yuki, Yoshikazu

2013-07-01

37

Evolutionary responses by native species to major anthropogenic changes to their ecosystems: Pacific salmon in the Columbia River hydropower system  

Microsoft Academic Search

The human footprint is now large in all the Earth's ecosystems, and construction of large dams in major river basins is among the anthropogenic changes that have had the most profound ecological consequences, particularly for migratory fishes. In the Columbia River basin of the western USA, considerable effort has been directed toward evaluating demo- graphic effects of dams, yet little

ROBIN S. WAPLES; RICHARD W. ZABEL; MARK D. SCHEUERELL; BETH L. SANDERSON

2007-01-01

38

Ecosystems  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on biodiversity within ecosystems and within species. Students visit a local area and collect leaves to demonstrate how diverse life can exist within a small area. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

2007-12-12

39

Genetic Analysis of Drought Resistance in Rice by Molecular Markers: Association between Secondary Traits and Field Performance  

Microsoft Academic Search

Genetic improvement of adaptation to drought is addressed through the conventional approach by se- Drought stress is the major constraint to rice (Oryza sativa L.) lecting for yield and its stability over locations and years. production and yield stability in rainfed ecosystems. Identifying geno- mic regions contributing to drought resistance will help develop rice Such selection programs are slow in

R. Chandra Babu; Bay D. Nguyen; Varapong Chamarerk; P. Shanmugasundaram; P. Chezhian; P. Jeyaprakash; S. K. Ganesh; A. Palchamy; S. Sadasivam; S. Sarkarung; L. J. Wade; Henry T. Nguyen

40

Diversity and population dynamics of pests and predators in irrigated rice fields with treated and untreated pesticide.  

PubMed

The monitoring of rice pests and their predators in pesticide untreated and treated rice fields was conducted at the southern of Thailand. Twenty-two species in 15 families and 6 orders of rice pests were sampled from untreated rice field. For treated rice field, 22 species in 14 families and 5 orders of rice pest were collected. Regardless of treatment type, dominant species and individual number of rice pest varied to physiological stage of rice. Lepidopteran pests had highest infestation during the vegetative stage of rice growth, while hemipteran pests composed of hopper species (Hemipetra: Auchenorrhyncha) and heteropteran species (Hemiptera: Heteroptera) were dominant groups during the reproductive stage and grain formation and ripening stage of rice growth. In contrast, dominant species of predator did not change throughout rice growing season. There were 35 species in 25 families and seven orders and 40 species in 29 families and seven orders of predators collected from untreated and treated rice field, respectively. Major predators of both rice fields were Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae), Tetragnatha sp. (Araneae: Tetragnathidae) and Agriocnemis pygmaea Rambur (Odonata: Agrionidae). The population dynamic of predators were not related with rice pest population in both treatments. However, the fluctuation of population pattern of rice pests in the untreated treatment were more distinctly synchronized with their predators than that of the treated treatment. There were no significant differences in the total number of rice pest and predator between two treatments at vegetative and reproductive stages of rice growth. Untreated rice field had a higher population number of predator and a lower population number of rice pest than that of treated rice field during grain formation and ripening stages. These results indicated the ago-ecosystem balance in rice fields could be produced through minimal pesticide application, in order to allow the natural balance between pests and their predators to be restored and maintained. PMID:23885426

Rattanapun, W

2012-01-01

41

Development of sustainable groundwater extraction practices for a major superficial aquifer supporting a groundwater dependent ecosystem  

Microsoft Academic Search

Throughout Australia many groundwater dependent ecosystems have been adversely affected by unsympathetic water abstraction practices. In Western Australia, the largest single supply of drinking water for the city of Perth is a superficial aquifer known as the Gnangara Groundwater Mound, located over an area of approximately 2200 km2 within and to the north of the city on the coastal plain.

K. R. Smettem; R. Froend; M. Davies; B. Stock; M. Martin; C. Robertson; D. Eamus

2010-01-01

42

Gene Expression Analysis of Rice Seedling under Potassium Deprivation Reveals Major Changes in Metabolism and Signaling Components  

PubMed Central

Plant nutrition is one of the important areas for improving the yield and quality in crops as well as non-crop plants. Potassium is an essential plant nutrient and is required in abundance for their proper growth and development. Potassium deficiency directly affects the plant growth and hence crop yield and production. Recently, potassium-dependent transcriptomic analysis has been performed in the model plant Arabidopsis, however in cereals and crop plants; such a transcriptome analysis has not been undertaken till date. In rice, the molecular mechanism for the regulation of potassium starvation responses has not been investigated in detail. Here, we present a combined physiological and whole genome transcriptomic study of rice seedlings exposed to a brief period of potassium deficiency then replenished with potassium. Our results reveal that the expressions of a diverse set of genes annotated with many distinct functions were altered under potassium deprivation. Our findings highlight altered expression patterns of potassium-responsive genes majorly involved in metabolic processes, stress responses, signaling pathways, transcriptional regulation, and transport of multiple molecules including K+. Interestingly, several genes responsive to low-potassium conditions show a reversal in expression upon resupply of potassium. The results of this study indicate that potassium deprivation leads to activation of multiple genes and gene networks, which may be acting in concert to sense the external potassium and mediate uptake, distribution and ultimately adaptation to low potassium conditions. The interplay of both upregulated and downregulated genes globally in response to potassium deprivation determines how plants cope with the stress of nutrient deficiency at different physiological as well as developmental stages of plants. PMID:23922980

Shankar, Alka; Singh, Amarjeet; Kanwar, Poonam; Srivastava, Ashish Kumar; Pandey, Amita; Suprasanna, Penna; Kapoor, Sanjay; Pandey, Girdhar K.

2013-01-01

43

Assessing Major Ecosystem Types and the Challenge of Sustainability in Turkey  

Microsoft Academic Search

In recent years, Turkey has experienced rapid economic and population growth coupled with both an equally rapid increase in\\u000a energy consumption and a vast disparity in welfare between socioeconomic groups and regions. In turn, these pressures have\\u000a accelerated the destruction of productive, assimilative, and regenerative capacities of the ecosystems, which are essential\\u000a for the well-being of the people and the

Fatih Evrendilek; Hakan Doygun

2000-01-01

44

Major Disturbance Events in Terrestrial Ecosystems Detected using Global Satellite Data Sets  

E-print Network

contribute to the current rise of carbon dioxide (CO2) levels in the atmosphere (Potter, 1999; Schimel et al., 2001). Because major `pulses' of CO2 from terrestrial biomass loss can be emitted to the atmosphere biogenic sources of CO2 have global implications for climatic change, which can in turn affect a vast

Kumar, Vipin

45

Influence of the Asian Monsoon on net ecosystem carbon exchange in two major plant functional types in Korea  

NASA Astrophysics Data System (ADS)

Considering the feedback loops in radiation, temperature, and soil moisture with alterations in rainfall patterns, the influence of the changing monsoon on net ecosystem CO2 exchange can be critical to the estimation of carbon balance in Asia. In this paper, we examined the eddy covariance CO2 fluxes observed from 2004 to 2008 in two major plant functional types in KoFlux, i.e., the Gwangneung deciduous forest (GDK) site and the Haenam farmland (HFK) site. The objectives of the study were to (1) quantify the net ecosystem CO2 exchange (NEE), ecosystem respiration (RE), and gross primary production (GPP), (2) examine their interannual patterns, and (3) assess the mechanism for the coupling of carbon and water exchange associated with the summer monsoon. The GDK site, which had a maximum leaf area index (LAI) of ~5, was on average a relatively weak carbon sink with NEE of -84 gC m-2 y-1, RE of 1028 gC m-2 y-1, and GPP of 1113 gC m-2 y-1. Despite about 20% larger GPP (of 1321 gC m-2 y-1) in comparison with the GDK site, the HFK site (with the maximum LAI of 3 to 4) was a weaker carbon sink with NEE of -58 gC m-2 y-1 because of greater RE of 1263 gC m-2 y-1. In both sites, the annual patterns of NEE and GPP had a striking "mid-season depression" each year with two distinctive peaks of different timing and magnitude, whereas RE did not. The mid-season depression at the GDK site occurred typically from early June to late August, coinciding with the season of summer monsoon when the solar radiation decreased substantially due to frequent rainfalls and cloudiness. At the HFK site, the mid-season depression began earlier in May and continued until the end of July due to land use management (e.g., crop rotation) in addition to such disturbances as summer monsoon and typhoons. Other flux observation sites in East Asia also show a decline in radiation but with a lesser degree during the monsoon season, resulting in less pronounced depression in NEE. In our study, however, the observed depression in NEE changed the forest and farmland from a carbon sink to a source in the middle of the growing season. Consequently, the annually integrated values of NEE lies on the low end of the range reported in the literature. Such a delicate coupling between carbon and water cycles may turn these ecosystems into a stronger carbon sink with the projected trends of less frequent but more intensive rainfalls in this region.

Kwon, H.; Kim, J.; Hong, J.

2009-11-01

46

Rice monoculture and integrated rice-fish farming in the Mekong Delta, Vietnam—economic and ecological considerations  

Microsoft Academic Search

This study is a survey of agriculture practices and pest management strategies among rice and rice-fish farmers in the Mekong Delta. Based on an economic comparison between different farmer categories, it is argued that rice-fish farming provides a sustainable alternative to rice monoculture, if the farmer takes full advantage of the natural productivity of the rice field ecosystem. The aim

Håkan Berg

2002-01-01

47

The usage of rice straw as a major substrate for the production of surfactin by Bacillus amyloliquefaciens XZ-173 in solid-state fermentation.  

PubMed

Agro-industrial byproducts, especially rice straw, are potential resources. This work was aimed to utilize raw materials to produce value-added biosurfactant in solid-state fermentation (SSF). Rice straw and soybean flour were found efficient and selected as major substrates for surfactin production. The results of Plackett-Burman design indicated that glycerol, water content, inoculum size and temperature were the significant variables identified in the screen of nine total variables. The optimum values for the four significant variables were determined by the Box-Behnken design. The optimal surfactin production was obtained when the medium contained 5 g soybean flour, 4 g rice straw, 2% (w/w) maltose and 2.65% (w/w) glycerol, pH 7.0. The ideal growth conditions for surfactin production consisted of a moisture content of 62.8% (v/w) and growth supplemented with 15.96% inoculum size in 250 mL flasks at 26.9 °C for 48 h. Under optimal conditions, a surfactin yield of 15.03 mg/gds was attained in 1000-fold scale-up fermentation in a 50 L fermenter, thereby validating the accuracy of this approach. This study proposed an eco-friendly and economical way to convert agro-industrial byproducts into biosurfactant. PMID:23685270

Zhu, Zhen; Zhang, Fengge; Wei, Zhong; Ran, Wei; Shen, Qirong

2013-09-30

48

Survey of major capsid genes ( g23) of T4-type bacteriophages in rice fields in Northeast China  

Microsoft Academic Search

We surveyed the capsid genes (g23) of T4-type bacteriophages in DNA extracted from fifteen rice field soils in Northeast China using primers MZIA1bis and MZIA6. Denaturing gradient gel electrophoresis (DGGE) was performed to separate PCR-amplified g23 products. In total, 53 DGGE bands were identified as g23 clones, nine of which belonged to a novel, Northeast China-specific group. In addition, four

Guanghua Wang; Jian Jin; Susumu Asakawa; Makoto Kimura

2009-01-01

49

Changes in major capsid genes ( g23 ) of T4-type bacteriophages with soil depth in two Japanese rice fields  

Microsoft Academic Search

Although microbial communities in soil are well known to change with soil depth, the changes in viral communities with soil\\u000a depth have not been documented. This study examined the soil depth profiles of T4-type phage communities in two Japanese rice\\u000a fields from g23 clones in soil DNA extracts to a depth of 1 m. T4-type phage communities changed with soil depth,

Guanghua Wang; Jun Murase; Katsutoshi Taki; Yoshinori Ohashi; Nanako Yoshikawa; Susumu Asakawa; Makoto Kimura

2009-01-01

50

Rice MAPKs.  

PubMed

Mitogen-activated protein kinase (MAPK) cascades are evolutionary conserved from unicellular to complex eukaryotic organisms, and constitute one of the major signalling pathways involved in regulating a wide range of cellular activities from growth and development to cell death. MAPKs of rice (Oryza sativa L.), the most important of all food crops and an established monocot plant research model, have seen considerable progress mainly on their identification and characterization during the past one year alone. These studies have provided new information on the response and regulation of rice MAPKs, in particular on their possible role/function in the rice self-defense pathways. It is believed that further work on MAPK cascades in rice will widen our understanding of the MAPK signalling pathways, and may lead to the establishment of a biological model on this critical early signalling event in monocots. In this review, we bring together all the recent developments in rice MAPKs and discuss their significance and future direction in light of the present data and the progress made in dicot model plants. PMID:12604328

Agrawal, Ganesh K; Iwahashi, Hitoshi; Rakwal, Randeep

2003-03-01

51

Transcriptome Profiling and Physiological Studies Reveal a Major Role for Aromatic Amino Acids in Mercury Stress Tolerance in Rice Seedlings  

PubMed Central

Mercury (Hg) is a serious environmental pollution threat to the planet. The accumulation of Hg in plants disrupts many cellular-level functions and inhibits growth and development, but the mechanism is not fully understood. To gain more insight into the cellular response to Hg, we performed a large-scale analysis of the rice transcriptome during Hg stress. Genes induced with short-term exposure represented functional categories of cell-wall formation, chemical detoxification, secondary metabolism, signal transduction and abiotic stress response. Moreover, Hg stress upregulated several genes involved in aromatic amino acids (Phe and Trp) and increased the level of free Phe and Trp content. Exogenous application of Phe and Trp to rice roots enhanced tolerance to Hg and effectively reduced Hg-induced production of reactive oxygen species. Hg induced calcium accumulation and activated mitogen-activated protein kinase. Further characterization of the Hg-responsive genes we identified may be helpful for better understanding the mechanisms of Hg in plants. PMID:24840062

Trinh, Ngoc Nam; Huang, Li-Yao; Chen, Ying-Chih; Cheng, Kai-Teng; Huang, Tsai-Lien; Lin, Chung-Yi; Huang, Hao-Jen

2014-01-01

52

Identification of qRL7, a major quantitative trait locus associated with rice root length in hydroponic conditions  

PubMed Central

Root system development is an important target for improving yield in rice. Active roots that can take up nutrients more efficiently are essential for improving grain yield. In this study, we performed quantitative trait locus (QTL) analyses using 215 recombinant inbred lines derived from a cross between Xieqingzao B (XB), a maintainer line with short roots and R9308, a restorer line with long roots. Only a QTLs associated with root length were mapped on chromosomes 7. The QTL, named qRL7, was located between markers RM3859 and RM214 on chromosome 7 and explained 18.14–18.36% of the total phenotypic variance evaluated across two years. Fine mapping of qRL7 using eight BC3F3 recombinant lines mapped the QTL to between markers InDel11 and InDel17, which delimit a 657.35 kb interval in the reference cultivar Nipponbare. To determine the genotype classes for the target QTL in these BC3F3 recombinants, the root lengths of their BC3F4 progeny were investigated, and the result showed that qRL7 plays a crucial role in root length. The results of this study will increase our understanding of the genetic factors controlling root architecture, which will help rice breeders to breed varieties with deep, strong and vigorous root systems. PMID:24273421

Wang, Huimin; Xu, Xiaoming; Zhan, Xiaodeng; Zhai, Rongrong; Wu, Weiming; Shen, Xihong; Dai, Gaoxing; Cao, Liyong; Cheng, Shihua

2013-01-01

53

qDTY1.1, a major QTL for rice grain yield under reproductive-stage drought stress with a consistent effect in multiple elite genetic backgrounds  

PubMed Central

Background Drought is one of the most important abiotic stresses causing drastic reductions in yield in rainfed rice environments. The suitability of grain yield (GY) under drought as a selection criterion has been reported in the past few years. Most of the quantitative trait loci (QTLs) for GY under drought in rice reported so far has been in the background of low-yielding susceptible varieties. Such QTLs have not shown a similar effect in multiple high- yielding drought-susceptible varieties, thus limiting their use in marker-assisted selection. Genetic control of GY under reproductive-stage drought stress (RS) in elite genetic backgrounds was studied in three F3:4 mapping populations derived from crosses of N22, a drought-tolerant aus cultivar, with Swarna, IR64, and MTU1010, three high-yielding popular mega-varieties, with the aim to identify QTLs for GY under RS that show a consistent effect in multiple elite genetic backgrounds. Three populations were phenotyped under RS in the dry seasons (DS) of 2009 and 2010 at IRRI. For genotyping, whole-genome scans for N22/MTU1010 and bulked segregant analysis for N22/Swarna and N22/IR64 were employed using SSR markers. Results A major QTL for GY under RS, qDTY1.1, was identified on rice chromosome 1 flanked by RM11943 and RM431 in all three populations. In combined analysis over two years, qDTY1.1 showed an additive effect of 29.3%, 24.3%, and 16.1% of mean yield in N22/Swarna, N22/IR64, and N22/MTU1010, respectively, under RS. qDTY1.1 also showed a positive effect on GY in non-stress (NS) situations in N22/Swarna, N22/IR64 over both years, and N22/MTU1010 in DS2009. Conclusions This is the first reported QTL in rice with a major and consistent effect in multiple elite genetic backgrounds under both RS and NS situations. Consistency of the QTL effect across different genetic backgrounds makes it a suitable candidate for use in marker-assisted breeding. PMID:22008150

2011-01-01

54

Sustainable Rice Production Through Farming Systems Approach  

Microsoft Academic Search

Field experiments were conducted for three years (from 1999 to 2002) at ICAR Research Complex for Goa, Old Goa, Goa, India, to identify a productive and sustainable cropping system with rice. Three major cropping systems common to the coastal region of India (rice–groundnut, rice–cowpea, and rice–vegetables) were compared with rice–fallow and rice–green manure (sunnhemp) systems. The experiment was conducted in

B. L. Manjunath; V. S. Korikanthimath

2009-01-01

55

Plant community dynamics in a semi-arid ecosystem in relation to nutrient addition following a major disturbance  

Microsoft Academic Search

Effects of annual additions of mineral N and P (100 kg ha-1) on plant species composition and annual aboveground net primary production (ANPP) were investigated during the first three years following disturbance in a semi-arid ecosystem. Additions of N reduced richness of perennial plant species during years 2 and 3, while P reduced the number of perennial species only in

Alan T. Carpenter; John C. Moore; Edward F. Redente; John C. Stark

1990-01-01

56

Effects of tillage during the nonwaterlogged period on nitrous oxide and nitric oxide emissions in typical Chinese rice-wheat rotation ecosystems  

NASA Astrophysics Data System (ADS)

Tillage practices result in major changes to soil environmental conditions and to the distribution of crop residues and nutrients in the soil profile, which may consequently affect the biogenic production and emission of N trace gases. To investigate the effects of tillage during the nonwaterlogged period on nitric oxide (NO) and nitrous oxide (N2O) emissions in rice-wheat rotation systems, we performed field experiments at three sites (Suzhou, Wuxi, and Jiangdu) in the Yangtze River Delta using static chamber techniques. The results showed that the effect of tillage on the emissions of both gases differed among the three field sites due to differences in agricultural management and soil texture. At the site with a light soil texture (Jiangdu: sandy loam), no tillage resulted in reduced NO emissions (0.5 kg N ha-1) as compared to conventionally tilled fields (0.9 kg N ha-1; p < 0.05). Regarding N2O, the no tillage plots showed significantly higher emissions (p < 0.05) in comparison to the tilled plots (3.9 versus 2.2 kg N ha-1) when the fields were merely amended with synthetic N fertilizers. However, this effect was not significant when wheat straw was used in addition to synthetic N fertilizers during the preceding rice season. In the clay loam soils (Wuxi), no tillage resulted in lower NO and higher N2O emissions from either N fertilized or unfertilized fields even though these results were not statistically significant. In the silty clay loam soils (Suzhou), which showed the highest soil organic carbon contents and the highest rates of N trace gas emissions in all three of the investigated sites, reduced tillage resulted in much higher NO emissions, whereas N2O emissions were not obviously influenced by tillage practices (reduced tillage versus tillage: NO, 9.5 versus 5.4 kg N ha-1; N2O, 10.6 versus 9.0 kg N ha-1). Similar effects of tillage were observed for the direct emission factors of the applied N during the wheat season. The observed emission factors for the different sites ranged from 0.3% to 2.4% for N2O (mean: 1.0%) and from 0.1% to 4.0% (mean: 0.9%) for NO, respectively. The observed site-to-site differences in emission factors are most likely the results of variations in soil properties (such as texture and pH) and agricultural practices (such as tillage and crop residue management) or in the amount and pattern of precipitation.

Yao, Zhisheng; Zhou, Zaixing; Zheng, Xunhua; Xie, Baohua; Liu, Chunyan; Butterbach-Bahl, Klaus; Zhu, Jianguo

2010-03-01

57

Predominant rice weeds in Nigeria  

Microsoft Academic Search

In a survey conducted in the four major rice ecological zones in Nigeria the predominant weeds of the flora growing in association with both direct?seeded and transplanted rice (Oryza sativa L.) were determined. Most of the predominant weed species differed with differing rice ecologies. Among the predominant broadleaved species, Ageratum conyzoides L., Sphenochlea zeylanica Gaertn, Tridax procumbens L., Portulaca oleracea

L. I. Okafor

1986-01-01

58

Texas Rice Production Guidelines  

E-print Network

wide crosses between elite Texas variet- ies and Oryza glaberrima as a potential source for major yield increases in Texas varieties beyond indica/japonica hybrids. Project Title: Plant Physiology Research. Texas Rice Ratoon Crop Management... wide crosses between elite Texas variet- ies and Oryza glaberrima as a potential source for major yield increases in Texas varieties beyond indica/japonica hybrids. Project Title: Plant Physiology Research. Texas Rice Ratoon Crop Management...

Way, M. O.; Cockrell, Jay

2008-03-11

59

EFFECTS OF CO2 ON COMPETITION BETWEEN RICE AND BARNYARDGRASS  

EPA Science Inventory

The atmospheric CO2 concentration is increasing. ffects of elevated CO2 on rice production could occur not only through direct impacts to rice, but also indirectly via ecosystem responses. hanged competitiveness with elevated CO2 could occur between rice hich has the C3 type of p...

60

Rice Distillers Dried Grain Is a Promising Ingredient as a Partial Replacement of Plant Origin Sources in the Diet for Juvenile Red Seabream (Pagrus major)  

PubMed Central

This study was designed to test the effects of dietary distillers dried grain (DDG) level on the growth performance, feed utilization, body composition and antioxidant activity of juvenile red seabream (Pagrus major). Six isonitrogenous and isocaloric diets were formulated to contain 0%, 5%, 10%, 15%, 20%, and 25% DDG from rice (designated as DDG0, DDG5, DDG10, DDG15, DDG20, and DDG25), respectively. Juvenile red seabream averaging 10.1±0.05 g were randomly distributed into 400-L tanks in a flow through systems. Three replicate groups of fish were fed one of the experimental diets to visual satiation two times a day for 10 weeks. Survival, weight gain, feed efficiency, protein efficiency ratio and hepatosomatic index of fish were not affected by dietary DDG levels (p>0.05). Proximate and amino acid composition of whole body in juvenile red seabream were not affected by dietary DDG levels (p>0.05). Plasma content of total protein, glucose, cholesterol, glutamic-pyruvic transaminase, phospholipid and triglyceride were not affected by dietary DDG levels (p>0.05). 1, 1-Diphenyl-2-picryl-hydrazyl radical and alkyl radical scavenging activities in plasma and liver of fish were not affected by dietary DDG levels (p>0.05). The results of this experiment suggest that DDG has the potential to replace plant origin ingredients such as wheat flour and corn gluten meal and could be used up to 25% in diet without incurring negative effects on the growth performance of juvenile red seabream. PMID:25358367

Choi, Jin; Rahman, Md Mostafizur; Lee, Sang-Min

2014-01-01

61

Rice Distillers Dried Grain Is a Promising Ingredient as a Partial Replacement of Plant Origin Sources in the Diet for Juvenile Red Seabream (Pagrus major).  

PubMed

This study was designed to test the effects of dietary distillers dried grain (DDG) level on the growth performance, feed utilization, body composition and antioxidant activity of juvenile red seabream (Pagrus major). Six isonitrogenous and isocaloric diets were formulated to contain 0%, 5%, 10%, 15%, 20%, and 25% DDG from rice (designated as DDG0, DDG5, DDG10, DDG15, DDG20, and DDG25), respectively. Juvenile red seabream averaging 10.1±0.05 g were randomly distributed into 400-L tanks in a flow through systems. Three replicate groups of fish were fed one of the experimental diets to visual satiation two times a day for 10 weeks. Survival, weight gain, feed efficiency, protein efficiency ratio and hepatosomatic index of fish were not affected by dietary DDG levels (p>0.05). Proximate and amino acid composition of whole body in juvenile red seabream were not affected by dietary DDG levels (p>0.05). Plasma content of total protein, glucose, cholesterol, glutamic-pyruvic transaminase, phospholipid and triglyceride were not affected by dietary DDG levels (p>0.05). 1, 1-Diphenyl-2-picryl-hydrazyl radical and alkyl radical scavenging activities in plasma and liver of fish were not affected by dietary DDG levels (p>0.05). The results of this experiment suggest that DDG has the potential to replace plant origin ingredients such as wheat flour and corn gluten meal and could be used up to 25% in diet without incurring negative effects on the growth performance of juvenile red seabream. PMID:25358367

Choi, Jin; Rahman, Md Mostafizur; Lee, Sang-Min

2014-12-01

62

Survey of arsenic and its speciation in rice products such as breakfast cereals, rice crackers and Japanese rice condiments  

Microsoft Academic Search

Rice has been demonstrated to be one of the major contributors to arsenic (As) in human diets in addition to drinking water, but little is known about rice products as an additional source of As exposure. Rice products were analyzed for total As and a subset of samples were measured for arsenic speciation using high performance liquid chromatography interfaced with

Guo-Xin Sun; Paul N. Williams; Yong-Guan Zhu; Claire Deacon; Anne-Marie Carey; Andrea Raab; Joerg Feldmann; Andrew A. Meharg

2009-01-01

63

Advances in Drought Resistance of Rice  

Microsoft Academic Search

Water deficit is a serious environmental stress and the major constraint to rice productivity. Losses in rice yield due to water shortage probably exceed losses from all other causes combined and the extent of the yield loss depends on both the severity and duration of the water stress. Drought affects rice at morphological, physiological, and molecular levels such as delayed

Muhammad Farooq; Abdul Wahid; Dong-Jin Lee; Osamu Ito; Kadambot H. M. Siddique

2009-01-01

64

Arsenic burden of cooked rice: Traditional and modern methods  

Microsoft Academic Search

Arsenic contamination of rice by irrigation with contaminated groundwater and secondarily increased soil arsenic compounds the arsenic burden of populations dependent on subsistence rice-diets. The arsenic concentration of cooked rice is known to increase with the arsenic concentration of the cooking water but the effects of cooking methods have not been defined. We tested the three major rice cooking procedures

M. K. Sengupta; M. A. Hossain; A. Mukherjee; S. Ahamed; B. Das; B. Nayak; A. Pal; D. Chakraborti

2006-01-01

65

Effects of UV-B and global climate change on rice production: The EPA\\/IRRI Cooperative Research Plan  

Microsoft Academic Search

The US Environmental Protection Agency and International Rice Research Institute are initiating a cooperative program on the effects of UV-B and global climate change (increased COâ and temperature) on rice. Rice is the world's most important food crop and responds both to UV-B and climate change. The project will determine: (1) the effects of these stresses on the rice ecosystem,

D. M. Olszyk; K. T. Ingram

1990-01-01

66

Candidacy of a chitin-inducible gibberellin-responsive gene for a major locus affecting plant height in rice that is closely linked to Green Revolution gene sd1.  

PubMed

Appropriate plant height is crucial for lodging resistance to improve the rice crop yield. The application of semi-dwarf 1 led to the green revolution in the 1960s, by predominantly increasing the rice yield. However, the frequent use of single sd1 gene sources may cause genetic vulnerability to pests and diseases. Identifying useful novel semi-dwarf genes is important for the genetic manipulation of plant architecture in practical rice breeding. In this study, introgression lines derived from two parents contrasting in plant height, Zhenshan 97 and Pokkali were employed to locate a gene with a large effect on plant height by the bulk segregant analysis method. A major gene, ph1, was mapped to a region closely linked to sd1 on chromosome 1; the additive effects of ph1 were more than 50 cm on the plant height and 2 days on the heading date in a BC(4)F(2) population and its progeny. ph1 was then fine mapped to BAC AP003227. Gene annotation indicated that LOC_OS01g65990 encoding a chitin-inducible gibberellin-responsive protein (CIGR), which belongs to the GRAS family, might be the right candidate gene of ph1. Co-segregation analysis of the candidate gene-derived marker finally confirmed its identity as the candidate gene. A higher expression level of the CIGR was detected in all the tested tissues in tall plants compared to those of short plants, especially in the young leaf sheath containing elongating tissues, which indicated its importance role in regulating plant height. ph1 showed a tremendous genetic effect on plant height, which is distinct from sd1 and could be a new resource for breeding semi-dwarf varieties. PMID:21637999

Kovi, Mallikarjuna Rao; Zhang, Yushan; Yu, Sibin; Yang, Gaiyu; Yan, Wenhao; Xing, Yongzhong

2011-09-01

67

Ecosystem Explorations  

NSDL National Science Digital Library

The Ecosystem Explorations curriculum includes eleven classroom lessons. The lessons are divided into two sections--Understanding Ecosystems and Human Connections to Ecosystems. The curriculum incorporates scientific inquiry skills, cooperative l

Gunckel, Kristen L.

1999-09-01

68

Leaching behavior of nitrogen in a long-term experiment on rice under different N management systems.  

PubMed

The leaching behavior of nitrogen was studied in single rice paddy production ecosystems in Tsukuba, Japan after 75 years of consistent fertilization regimes (no fertilizer, ammonium sulfate, a combination of composted rice straw with soybean cake, and fresh clover). During the 75-year period, management was unchanged with respect to rice planting density, irrigation, and net N fertilization for each field to which an N-source was added. Percolation water was collected, from May 2001 to April 2002, using porous suction cups installed in the fields at depths of 15, 40, and 60 cm. All water samples were taken to the laboratory for the measurement of both NH(4) (?+?)-N and NO(3) (?-?)-N concentrations using a continuous-flow nitrogen analyzer. The result indicated that there were significant differences in N leaching losses between treatments during the rice growing season. Total N leaching was significantly lower with the application of composted rice straw plus soybean cake (0.58 kg N ha(?-?1)) than with ammonium sulfate (2.41 kg N ha(?-?1)), which resulted in N leaching at a similar level to that with the fresh clover treatment (no significant difference). The majority of this N leaching was not due to NO(3) (?-?)-N loss, but to that of NH(4) (?+?)-N. The mean N leaching for all fertilizer treatments during the entire rice growing season was 1.58 kg N ha(?-?1). Composted rice straw plus soybean cake produced leaching losses which were 65-75% lower than those with the application of fresh clover and ammonium sulfate. N accumulation resulting from nitrification in the fallow season could be a key source of nitrate-N leaching when fields become re-flooded before rice transplanting in the following year; particular attention should be paid to this phenomenon. PMID:20676930

Luo, Liang-Guo; Itoh, Sumio; Zhang, Qing-Wen; Yang, Shi-Qi; Zhang, Qing-Zhong; Yang, Zheng-Li

2011-06-01

69

TITLE: Ecosystem Services: An Interdisciplinary Conversation and More HOSTS: Steven Wolf and Alex Flecker  

E-print Network

TITLE: Ecosystem Services: An Interdisciplinary Conversation and More HOSTS: Steven Wolf and Alex Flecker DATE: September 17, 12-1pm, 300 Rice Hall Abstract: The concept of ecosystem services of the ecosystem services concept are contested. On one hand, expressing the significance of ecosystems in terms

Angenent, Lars T.

70

Energy flow through an Apatani village ecosystem of Arunachal Pradesh in northeast India  

Microsoft Academic Search

The energy flow through the ecosystem of a typical Apatani village in Arunachal Pradesh in northeastern India was studied. The energy and economic efficiency of the rice agro-ecosystem of this region is exceptionally high, and rice is exported after meeting local needs. The cropping pattern varies depending upon the amount of organic residues recycled into the system. Where recycling is

Anil Kumar I; P. S. Ramakrishnan

1990-01-01

71

Antarctica: A Cold Desert Ecosystem  

NSDL National Science Digital Library

This Antarctica lesson has students locate the continent on a globe and on a map, describe and illustrate major Antarctic ecosystems, and explain relationships between those ecosystems. They will also construct a rough map of Antarctic ecosystems and explore relationships among the creatures that populate them. This lesson can be adapted to focus on other regions, including the one in which students live.

72

Interaction of beggiatoa and rice plant: detoxification of hydrogen sulfide in the rice rhizosphere.  

PubMed

Beggiatoa was obtained from six habitats, including four water-saturated soils from rice fields. The isolate of Beggiatoa from Bernard clay, when reinoculated into soil treatments from pure culture, significantly reduced hydrogen sulfide levels in soils and increased oxygen release from rice plants. Rice plants significantly increased Beggiatoa survival in flooded soils. Some hydrogen sulfide was necessary for survival of the Bernard clay isolate; high concentrations of hydrogen sulfide killed the Bernard clay isolate but were tolerated by a Crowley silt loam isolate from Eagle Lake, Texas. The results suggest that Beggiatoa may be an element of wetlands plant ecosystems. PMID:17844038

Joshi, M M; Hollis, J P

1977-01-14

73

Phylogenetic diversity and assemblage of major capsid genes (g23) of T4-type bacteriophages in paddy field soils during rice growth season in Northeast China  

Microsoft Academic Search

Although bacteriophages (phages) are ubiquitous and the most abundant biological entities on Earth, the genetic information on their diversity and community composition in natural environments, particularly in soils, is limited. This study elucidated the diversity and composition of T4-type phages by analyzing partial major capsid gene (g23) sequences in DNA extracts from five paddy field soils in Northeast China during

Junjie Liu; Guanghua Wang; Qiang Wang; Judong Liu; Jian Jin; Xiaobing Liu

2012-01-01

74

ASSESSMENT OF THE EFFECT OF CLIMATE CHANGE ON BORO RICE PRODUCTION IN BANGLADESH USING CERES-RICE MODEL  

Microsoft Academic Search

Effect of climate change on yield of two varieties of boro rice has been assessed using the CERES- Rice model of the DSSAT modeling system. The yield of BR3 and BR14 boro varieties for the years 2008, 2030, 2050 and 2070 have been simulated for 12 locations (districts) of Bangladesh, which were selected from among the major rice growing areas

Jayanta Kumar Basak; M. Ashraf Ali

75

The role of momilactones in rice allelopathy.  

PubMed

Large field screening programs and laboratory experiments in many countries have indicated that rice is allelopathic and releases allelochemical(s) into its environment. A number of compounds, such as phenolic acids, fatty acids, phenylalkanoic acids, hydroxamic acids, terpenes, and indoles, have been identified as potential rice allelochemicals. However, the studies reviewed here demonstrate that the labdane-related diterpenoid momilactones are the most important, with momilactone B playing a particularly critical role. Rice plants secrete momilactone B from their roots into the neighboring environments over their entire life cycle at phytotoxic levels, and momilactone B seems to account for the majority of the observed rice allelopathy. In addition, genetic studies have shown that selective removal of the momilactones only from the complex mixture found in rice root exudates significantly reduces allelopathy, demonstrating that these serve as allelochemicals, the importance of which is reflected in the presence of a dedicated momilactone biosynthetic gene cluster in the rice genome. PMID:23385366

Kato-Noguchi, Hisashi; Peters, Reuben J

2013-02-01

76

A simulation model for investigating the effects of rice paddy fields on the runoff system  

Microsoft Academic Search

Rice production in Taiwan is likely to decrease because of two major threats: an increase in the industrial demand on water resources and cheaper imported rice resulting from the free trade policy which will be enforced when Taiwan joins the World Trade Organization. A shrinkage in rice paddy acreage raises environmental concerns, especially in relation to water conservation. Besides rice

Ray-Shyan Wu; Wen-Ray Sue; Chuan-Bin Chien; Ching-Ho Chen; Jia-Shien Chang; Kuei-Miao Lin

2001-01-01

77

Suppression of rice methane emission by sulfate deposition in simulated acid rain  

E-print Network

from rice agriculture may be similarly affected by acid rain, a major and increasing pollution problem from rice agriculture. Emissions from rice plants treated with simulated acid rain at levels of SO4 2Ã? with respect to water management and fertilizer use change [Khalil and Shearer, 2006]. In rice agro

Gauci, Vincent

78

Australian Wild Rice Reveals Pre-Domestication Origin of Polymorphism Deserts in Rice Genome  

PubMed Central

Background Rice is a major source of human food with a predominantly Asian production base. Domestication involved selection of traits that are desirable for agriculture and to human consumers. Wild relatives of crop plants are a source of useful variation which is of immense value for crop improvement. Australian wild rices have been isolated from the impacts of domestication in Asia and represents a source of novel diversity for global rice improvement. Oryza rufipogon is a perennial wild progenitor of cultivated rice. Oryza meridionalis is a related annual species in Australia. Results We have examined the sequence of the genomes of AA genome wild rices from Australia that are close relatives of cultivated rice through whole genome re-sequencing. Assembly of the resequencing data to the O. sativa ssp. japonica cv. Nipponbare shows that Australian wild rices possess 2.5 times more single nucleotide polymorphisms than in the Asian wild rice and cultivated O. sativa ssp. indica. Analysis of the genome of domesticated rice reveals regions of low diversity that show very little variation (polymorphism deserts). Both the perennial and annual wild rice from Australia show a high degree of conservation of sequence with that found in cultivated rice in the same 4.58Mbp region on chromosome 5, which suggests that some of the ‘polymorphism deserts’ in this and other parts of the rice genome may have originated prior to domestication due to natural selection. Conclusions Analysis of genes in the ‘polymorphism deserts’ indicates that this selection may have been due to biotic or abiotic stress in the environment of early rice relatives. Despite having closely related sequences in these genome regions, the Australian wild populations represent an invaluable source of diversity supporting rice food security. PMID:24905808

Krishnan S., Gopala; Waters, Daniel L. E.; Henry, Robert J.

2014-01-01

79

Florida Ecosystems  

NSDL National Science Digital Library

Provided by FICUS (the Florida Internet Center for Understanding Sustainability) and the University of South Florida, this gem of a site covers Florida's native upland, freshwater, and marine ecosystems. Streamlined in organization but solid in content, Florida Ecosystems offers introductory information and photographic images of a dozen ecosystems, ranging from Pine Flatwoods and Dry Prairies to Mangrove Swamps and Coral Reefs. For students and educators interested in subtropical ecosystems, this is a nice place to start.

80

GE540 Ecosystem Services Spring Semester 2012  

E-print Network

1 GE540 ­ Ecosystem Services Spring Semester 2012 TR 2:00­3:30 (STO 465) Professor: Dana Bauer-353-7555 or by appointment bauer@bu.edu Course Description: Ecosystems provide a variety of valuable services that improve human well-being. The Millennium Ecosystem Assessment defines four major categories of ecosystem

Bauer, Dana Marie

81

Rice Varieties.  

E-print Network

and family Gramineae. Most cultivated varieties are the species Oryza sativa L., although varieties of the species O. glaberrima are cultivated in Africa. O. sativa is an annual but when moisture and temperature are optimum and diseases are absent..., plants have survived and produced grain for 20 years or more. All rice varieties grown in the United States are in the species O. sativa L. Commercial varieties are classified according to length of growing season, size and shape of grain...

Hodges, R. J.; Bollich, C. N.; Marchetti, M. A.; Webb, B. D.

1979-01-01

82

Ecosystem Jenga!  

ERIC Educational Resources Information Center

To give students a tangible model of an ecosystem and have them experience what could happen if a component of that ecosystem were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced ecosystem through a modification of the popular game Jenga. This activity can be…

Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.

2009-01-01

83

Ecosystem Journalism  

ERIC Educational Resources Information Center

If the organisms in a prairie ecosystem created a newspaper, what would it look like? What important news topics of the ecosystem would the organisms want to discuss? Imaginative and enthusiastic third-grade students were busy pondering these questions as they tried their hands at "ecosystem journalism." The class had recently completed a study of…

Robertson, Amy; Mahlin, Kathryn

2005-01-01

84

Characterization of paralogous protein families in rice  

E-print Network

Background: High gene numbers in plant genomes reflect polyploidy and major gene duplication events. Oryza sativa, cultivated rice, is a diploid monocotyledonous species with a ~390 Mb genome that has undergone segmental ...

Lin, Haining

85

Candidacy of a chitin-inducible gibberellin-responsive gene for a major locus affecting plant height in rice that is closely linked to Green Revolution gene sd1  

Microsoft Academic Search

Appropriate plant height is crucial for lodging resistance to improve the rice crop yield. The application of semi-dwarf 1 led to the green revolution in the 1960s, by predominantly increasing the rice yield. However, the frequent use of single\\u000a sd1 gene sources may cause genetic vulnerability to pests and diseases. Identifying useful novel semi-dwarf genes is important\\u000a for the genetic

Mallikarjuna Rao Kovi; Yushan Zhang; Sibin Yu; Gaiyu Yang; Wenhao Yan; Yongzhong Xing

86

The complete sequence of the rice ( Oryza sativa ) chloroplast genome: Intermolecular recombination between distinct tRNA genes accounts for a major plastid DNA inversion during the evolution of the cereals  

Microsoft Academic Search

Summary  The entire chloroplast genome of the monocot rice (Oryza sativa) has been sequenced and comprises 134525 bp. Predicted genes have been identified along with open reading frames (ORFs) conserved\\u000a between rice and the previously sequenced chloroplast genomes, a dicot, tobacco (Nicotiana tabacum), and a liverwort (Marchantia polymorpha). The same complement of 30 tRNA and 4 rRNA genes has been conserved

Junzou Hiratsuka; Hiroaki Shimada; Robert Whittier; Takashi Ishibashi; Masahiro Sakamoto; Masao Mori; Chihiro Kondo; Yasuko Honji; Chong-Rong Sun; Bing-Yuan Meng; Yu-Qing Li; Akira Kanno; Yoko Nishizawa; Atsushi Hirai; Kazuo Shinozaki; Masahiro Sugiura

1989-01-01

87

Mapping of seed shattering loci provides insights into origin of weedy rice and rice domestication.  

PubMed

Seed shattering is an important trait that distinguishes crop cultivars from the wild and weedy species. The genetics of seed shattering was investigated in this study to provide insights into rice domestication and the evolution of weedy rice. Quantitative trait locus (QTL) analysis, conducted in 2 recombinant inbred populations involving 2 rice cultivars and a weedy rice accession of the southern United States, revealed 3-5 QTLs that controlled seed shattering with 38-45% of the total phenotypic variation. Two QTLs on chromosomes 4 and 10 were consistent in both populations. Both cultivar and weedy rice contributed alleles for increased seed shattering. Genetic backgrounds affected both QTL number and the magnitude of QTL effects. The major QTL qSH4 and a minor QTL qSH3 were validated in near-isogenic lines, with the former conferring a significantly higher degree of seed shattering than the latter. Although the major QTL qSH4 overlapped with the sh4, the presence of the nonshattering single nucleotide polymorphism allele in the weedy rice accession suggested involvement of a linked locus or an alternative molecular genetic mechanism. Overlapping of several QTLs with those from earlier studies indicated that weedy rice may have been derived from the wild species Oryza rufipogon. Natural hybridization of rice cultivars with the highly variable O. rufipogon present in different geographic regions might be responsible for the evolution of a wide range of phenotypic and genotypic variabilities seen in weedy rice populations worldwide. PMID:24336929

Subudhi, Prasanta K; Singh, Pradeep K; DeLeon, Teresa; Parco, Arnold; Karan, Ratna; Biradar, Hanamareddy; Cohn, Marc A; Sasaki, Takuji

2014-01-01

88

The Rice Genome Knowledgebase (RGKbase): an annotation database for rice comparative genomics and evolutionary biology.  

PubMed

Over the past 10 years, genomes of cultivated rice cultivars and their wild counterparts have been sequenced although most efforts are focused on genome assembly and annotation of two major cultivated rice (Oryza sativa L.) subspecies, 93-11 (indica) and Nipponbare (japonica). To integrate information from genome assemblies and annotations for better analysis and application, we now introduce a comparative rice genome database, the Rice Genome Knowledgebase (RGKbase, http://rgkbase.big.ac.cn/RGKbase/). RGKbase is built to have three major components: (i) integrated data curation for rice genomics and molecular biology, which includes genome sequence assemblies, transcriptomic and epigenomic data, genetic variations, quantitative trait loci (QTLs) and the relevant literature; (ii) User-friendly viewers, such as Gbrowse, GeneBrowse and Circos, for genome annotations and evolutionary dynamics and (iii) Bioinformatic tools for compositional and synteny analyses, gene family classifications, gene ontology terms and pathways and gene co-expression networks. RGKbase current includes data from five rice cultivars and species: Nipponbare (japonica), 93-11 (indica), PA64s (indica), the African rice (Oryza glaberrima) and a wild rice species (Oryza brachyantha). We are also constantly introducing new datasets from variety of public efforts, such as two recent releases-sequence data from ?1000 rice varieties, which are mapped into the reference genome, yielding ample high-quality single-nucleotide polymorphisms and insertions-deletions. PMID:23193278

Wang, Dapeng; Xia, Yan; Li, Xinna; Hou, Lixia; Yu, Jun

2013-01-01

89

Rice Diseases.  

E-print Network

for different disease-causing organisms. Sclerotia of Rhizoctonia solani (the fungus that causes sheath blight) survive an average of 12 to 18 months in the soil. Kernel smut fungus spores (Neouossia horrida) can remain alive more than 10 years. As a result... chart (table 1) for specific recommendations. SOUTHERN BLIGHT (fungus - Sclerotium ro lIs ii) Southern blight can attack rice in the one- to three leaf stage and may kill large numbers of plants when weather is warm and moist. A white cottony mold...

Jones, Roger K.

1987-01-01

90

Antioxidants and antioxidant activity of several pigmented rice brans.  

PubMed

This study investigated the antioxidant content and activity of phenolic acids, anthocyanins, ?-tocopherol and ?-oryzanol in pigmented rice (black and red rice) brans. After methanolic extraction, the DPPH free radical scavenging activity and antioxidant activity were measured. The pigmented rice bran extract had a greater reducing power than a normal rice bran extract from a long grain white rice. All bran extracts were highly effective in inhibiting linoleic acid peroxidation (60-85%). High-performance liquid chromatography (HPLC) analysis of antioxidants in rice bran found that ?-oryzanol (39-63%) and phenolic acids (33-43%) were the major antioxidants in all bran samples, and black rice bran also contained anthocyanins 18-26%. HPLC analysis of anthocyanins showed that pigmented bran was rich in cyanidin-3-glucoside (58-95%). Ferulic acid was the dominant phenolic acid in the rice bran samples. Black rice bran contained gallic, hydroxybenzoic, and protocatechuic acids in higher contents than red rice bran and normal rice bran. Furthermore, the addition of 5% black rice bran to wheat flour used for making bread produced a marked increase in the free radical scavenging and antioxidant activity compared to a control bread. PMID:21141962

Laokuldilok, Thunnop; Shoemaker, Charles F; Jongkaewwattana, Sakda; Tulyathan, Vanna

2011-01-12

91

Morphology based field rice density detection from rice transplant stage to rice jointing stage  

NASA Astrophysics Data System (ADS)

Rice yield estimation is an important aspect in the agriculture research field. For the rice yield estimation, rice density is one of its useful factors. In this paper, we propose a new method to automatically detect the rice density from the rice transplanting stage to rice jointing stage. It devotes to detect rice planting density by image low-level features of the rice image sequences taken in the fields. Moreover, a rice jointing stage automatic detection method is proposed so as to terminate the rice density detection algorithm. The validities of the proposed rice density detection method and the rice jointing stage automatic detection method are proved in the experiment.

Bai, X. D.; Cao, Z. G.; Wang, Y.; Ye, M. N.; Yu, Z. H.; Li, Y. N.

2013-10-01

92

Freshwater Ecosystems  

NSDL National Science Digital Library

In this activity, learners create a freshwater ecosystem in a large plastic bottle. Learners cut and prepare bottles, then fill with water, aquatic plants, snails and fish. Learners observe their mini-ecosystem over time to see what changes--such as the color of the water, the water temperature, plant growth, and behavior and/or population of the snails or fish. The activity serves as a model for larger freshwater ecosystems such as ponds, lakes, rivers, streams, wetlands, reservoirs and groundwater.

Jersey, New; Center, Liberty S.; Coalition, New J.

2006-01-01

93

Coral Ecosystems  

NSDL National Science Digital Library

Why study coral ecosystems? Having survived millions of years, coral reefs are among the oldest and most diverse ecosystems on earth. Learning about coral ecosystems encompasses many of the 9-12 grade science curriculum standards. Life cycles of organisms, biological structure and function of organisms, and the behaviors and adaptations of organisms to their environment are all topics easily studied through a focus on coral reefs. All populations in this ecosystem are interdependent and part of a global food web. Healthy coral ecosystems are important to the humans, plants, fish, and other organisms that depend on them. However, the increasing impact of climate changes and human activities is endangering the very survival of these ecosystems. Pollution, habitat loss, invasive species, and diseases are all threats to the survival of coral ecosystems around the globe. Learning about them- "their fragility and value"- will help students understand what is needed to protect them. This SciGuide highlights outstanding NOAA resources, such as online tutorials and complete, hands-on, inquiry based lesson plans from the National Ocean Services. These resources address three areas. First, students can study the biology of the coral organism, learning about types of coral and where they are found. Next, resources focus on the populations, habitat, and dynamics of coral ecosystems. Finally, teachers and students, through online data sources and activities, learn about conservation of our coral ecosystems. Natural threats, human disturbances, and the benefits of coral protection focus students on the real world importance of science learning.

National Science Teachers Association (NSTA)

2006-06-01

94

The impact of herbicide-resistant rice technology on phenotypic diversity and population structure of United States weedy rice.  

PubMed

The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. PMID:25122473

Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D; Huang, Zhongyun; Hyma, Katie E; Gealy, David R; Caicedo, Ana L

2014-11-01

95

Silicate fertilization in no-tillage rice farming for mitigation of methane emission and increasing rice productivity  

Microsoft Academic Search

Agricultural practices mostly influence methane (CH4) emissions from rice field, which must be controlled for maintaining the ecosystem balance. No-tillage farming with chemical amendments having electron acceptors could be an effective mitigation strategy in CH4 emissions from irrigated rice (Oryza sativa L.) field. An experiment was conducted in Korean paddy field under tillage and no-tillage farming practices with silicate iron

Muhammad Aslam Ali; Chang Hoon Lee; Yong Bok Lee; Pil Joo Kim

2009-01-01

96

Investigations of methane emissions from rice cultivation in Indian context.  

PubMed

The increasing demand of the growing population requires enhancement in the production of rice. This has a direct bearing on the global environment since the rice cultivation is one of the major contributors to the methane emissions. As the rice cultivation is intensified with the current practices and technologies, the methane fluxes from paddy fields will substantially rise. Improved high yielding rice varieties together with efficient cultivation techniques will certainly contribute to the curtailment of the methane emission fluxes. In this paper, the system dynamic approach is used for estimating the methane emissions from rice fields in India till the year 2020. Mitigation options studied for curtailing the methane emissions include rice production management, use of low methane emitting varieties of rice, water management and fertilizer amendment. The model is validated quantitatively and sensitivity tests are carried out to examine the robustness of the model. PMID:15788188

Anand, Shalini; Dahiya, R P; Talyan, Vikash; Vrat, Prem

2005-05-01

97

AQUATIC ECOSYSTEMS,  

EPA Science Inventory

Aquatic ecosystems are a vital part of the urban water cycle (and of urban areas more broadly), and, if healthy, provide a range of goods and services valued by humans (Meyer 1997). For example, aquatic ecosystems (e.g., rivers, lakes, wetlands) provide potable water, food resou...

98

Integrated management to reduce rodent damage to lowland rice crops in Indonesia  

E-print Network

Integrated management to reduce rodent damage to lowland rice crops in Indonesia Grant R. Singletona,*, Sudarmajib , J. Jacoba , C.J. Krebsa a CSIRO Sustainable Ecosystems, G.P.O. Box 284, Canberra, A.C.T. 2601, Australia b Indonesian Institute for Rice Research, Jl Raya No. 9, Sukamandi

Krebs, Charles J.

99

Isolation of rice allergenic cDNA clones from a rice cDNA library by immunoscreening with a polyclonal antibody specific to 16 kD rice allergenic protein  

Microsoft Academic Search

Clinical cases of type-1 hypersensitive reaction to rice (Oryza sativa) have been reported in western countries as well as in Japan. Among rice proteins, 14-16 kD globulin proteins encoded by multiple gene family have been identified as major rice allergens. In this study, a rice cDNA library was constructed using ? ? ? ? UniZap vector and screened with a

Nam-il Kim; Woo-chang Kim; Sang-mi Lee; Hee-kyeong Lee; Hae-ik Rhee; Yong-soon Choi; Yeon-ho Jung; Sang-hoon Cha

100

Texas Rice, Volume IV, Number 6  

E-print Network

explorations, and for formulating strategies to ge- netically modify this major cereal crop to form an intimate symbiosis with rhizobia. In a 2001 report to the Rural Industries Research and Development Corporation of Australia, Dr. B.G. Rolfe described his... findings regarding rice cultivars and endophytic bacteria. Rolfe postulated that the pos- sibility of establishing a more effective type of Rhizo- bium-non-legume interaction is potentially available in rice because many of the plant compounds that could...

101

Shelf-sea ecosystems  

SciTech Connect

An analysis of the food chain dynamics of the Oregon, Alaskan, and New York shelves is made with respect to differences in physical forcing of these ecosystems. The world's shelves are 10% of the area of the ocean, yield 99% of the world's fish catch, and may be a major sink in the global CO/sub 2/ budget.

Walsh, J J

1980-01-01

102

Effects on aquatic ecosystems  

Microsoft Academic Search

Regarding the effects of UV-B radiation on aquatic ecosystems, recent scientific and public interest has focused on marine primary producers and on the aquatic web, which has resulted in a multitude of studies indicating mostly detrimental effects of UV-B radiation on aquatic organisms. The interest has expanded to include ecologically significant groups and major biomass producers using mesocosm studies, emphasizing

D.-P. Häder; H. D. Kumar; R. C. Smith; R. C. Worrest

1998-01-01

103

[Vaginal ecosystem].  

PubMed

The vagina is original biotype with its own ecosystem, according to medical ecology science. This ecosystem has dynamic, but very unstable equilibrium. Disturb equilibrium is known as a disbiosys. It was discussed different components of this ecosystem: morphology of vaginal walls, vaginal liquidity, lacto-acid and residental flora, "invader" microorganisms, vaginal acidity, immune processes. It was shared our own experience with medicine Polygynax, remedy of Laboratoire Innotech International (Paris, France). Polygynax has such an advantage - rapidly restore disturbed ecological equlibrium in case of bacterial vulvovaginitis, caused mainly of intestine pathogenic flora. PMID:15673027

Karag'ozov, I; Shopova, E; Andreeva, P

2004-01-01

104

Direct and reverse pollen-mediated gene flow between GM rice and red rice weed  

PubMed Central

Potential risks of genetically modified (GM) crops must be identified before their commercialization, as happens with all new technologies. One of the major concerns is the proper risk assessment of adventitious presence of transgenic material in rice fields due to cross-pollination. Several studies have been conducted in order to quantify pollen-mediated gene flow from transgenic rice (Oryza sativa) to both conventional rice and red rice weed (O. sativa f. spontanea) under field conditions. Some of these studies reported GM pollen-donor rice transferring GM traits to red rice. However, gene flow also occurs in the opposite direction, in a phenomenon that we have called reverse gene flow, resulting in transgenic seeds that have incorporated the traits of wild red rice. We quantified reverse gene flow using material from two field trials. A molecular analysis based on amplified fragment length polymorphisms was carried out, being complemented with a phenotypic identification of red rice traits. In both field trials, the reverse gene flow detected was greater than the direct gene flow. The rate of direct gene flow varied according to the relative proportions of the donor (GM rice) and receptor (red rice) plants and was influenced by wind direction. The ecological impact of reverse gene flow is limited in comparison with that of direct gene flow because non-shattered and non-dormant seeds would be obtained in the first generation. Hybrid seed would remain in the spike and therefore most of it would be removed during harvesting. Nevertheless, this phenomenon must be considered in fields used for elite seed production and in developing countries where farmers often keep some seed for planting the following year. In these cases, there is a higher risk of GM red rice weed infestation increasing from year to year and therefore a proper monitoring plan needs to be established.

Serrat, X.; Esteban, R.; Peñas, G.; Català, M. M.; Melé, E.; Messeguer, J.

2013-01-01

105

Ecosystem Valuation  

NSDL National Science Digital Library

Developed as a collaborative project of the US Department of Agriculture, Natural Resource Conservation Service, US Department of Commerce, NOAA-Sea Grant Office, and University of Maryland, Center for Environmental Science, this new Website examines how economists attempt to assign values to ecosystem services. The site is well organized and outlines general and specific topics under the following sections: The Big Picture, Essentials of Ecosystem Valuation, Dollar-based Ecosystem Valuation Methods, Ecosystem Benefit Indicators, and Links. Topics are explained in terms that laypersons will understand (a glossary is also provided) but without compromising the quality of information. Anyone interested in learning more about this controversial but increasingly important area will find this site an excellent starting point.

106

The Recursion . . . Extended Rice . . .  

E-print Network

application, we get a very short proof of Rice's Theorem. Let C be such that PC = and PC = N, and let j PCThe Recursion . . . Extended Rice . . . Creative and . . . Home Page Title Page Page 388 of 405 Go . . . Extended Rice . . . Creative and . . . Home Page Title Page Page 389 of 405 Go Back Full Screen Close Quit

Gallier, Jean

107

ECOSYSTEM HEALTH: ENERGY INDICATORS  

EPA Science Inventory

1. Ecosystem Health and Ecological Integrity 2. Historical Background on Ecosystem Health 3. Energy Systems Analysis, Health and Emergy 4. Energy and Ecosystems 5. Direct Measures of Ecosystem Health 6. Indirect Measures of Ecosystem Health...

108

Monitoring fire activities in the boreal ecosystem  

Microsoft Academic Search

Forest fire is a major disturbance to the boreal ecosystem and may interact with climate change. Unfortunately, we have relatively little knowledge regarding fire activities in the boreal ecosystem. This study investigates the extent and dynamics of the forest fires occurred in and around the Boreal Ecosystem-Atmosphere Study (BOREAS) region during summer 1994, an active fire season on record. The

Zhanqing Li; Josef Cihlar; Louis Moreau; Fengting Huang; Bryan Lee

1997-01-01

109

Texas Rice, Highlights in Research  

E-print Network

industry for the devel- opment and registration of experimental herbicides in weed control systems, and for expansion of uses of presently labeled herbicides. The research has played a major role in the development and introduction of Arrosolo, Basagran... involved in two projects. In one project, she is examining control of red rice using a combination of herbicide treatment and water management. She is also working on a novel strategy to enhance ratoon yield by manipulation of nitrogen metabolism using GMO...

2002-01-01

110

Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA  

PubMed Central

The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta) found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH), suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s) required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta), not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing. PMID:22043312

Lee, Seonghee; Jia, Yulin; Jia, Melissa; Gealy, David R.; Olsen, Kenneth M.; Caicedo, Ana L.

2011-01-01

111

Modelling the impacts of climate change and methane emission reductions on rice production: a review  

Microsoft Academic Search

Rice agriculture is not only affected by climate change, but also contributes to global warming through the release of methane into the atmosphere. In 1989, a major research project was initiated at the International Rice Research Institute in the Philippines to investigate relationships between climate change and rice production. A second project started in 1993 to investigate, in more detail,

Robin Matthews; Reiner Wassmann

2003-01-01

112

Speciation And Distribution Of Arsenic And Localization Of Nutrients In Rice Grains  

EPA Science Inventory

Arsenic (As) contamination of rice grains and the generally low concentration of micronutrients in rice have been recognized as a major concern for human health. Here, we investigated the speciation and localization of As and the distribution of (micro)nutrients in rice grains b...

113

Characterizing the Saltol Quantitative Trait Locus for Salinity Tolerance in Rice  

E-print Network

Characterizing the Saltol Quantitative Trait Locus for Salinity Tolerance in Rice Michael J for areas with higher salt stress. Keywords Allelic variation . MABC . Near isogenic lines . Rice . Salt stress . Saltol QTL Introduction Salt stress is a major constraint across many rice production areas

Blumwald, Eduardo

114

Habitat use, migration pattern and population dynamics of chevron snakehead Channa striata in a rainfed rice  

E-print Network

in a rainfed rice farming landscape E. AMILHAT* AND K. LORENZEN Division of Biology, Imperial College London Channa striata in a rainfed rice farming landscape of north-east Thailand were studied through a tagging dry season, and in the beginning and at the end of the wet season. Rice fields provided the major wet

Lorenzen, Kai

115

Characterizing the Saltol Quantitative Trait Locus for Salinity Tolerance in Rice  

E-print Network

Characterizing the Saltol Quantitative Trait Locus for Salinity Tolerance in Rice Michael J with higher salt stress. Keywords Allelic variation . MABC . Near isogenic lines . Rice . Salt stress . Saltol QTL Introduction Salt stress is a major constraint across many rice production areas because

Blumwald, Eduardo

116

Levels and Patterns of Nucleotide Variation in Domestication QTL Regions on Rice Chromosome 3  

E-print Network

and selective basis for domestication between these two Asian rice varietal groups. Citation: Xie X, Molina JLevels and Patterns of Nucleotide Variation in Domestication QTL Regions on Rice Chromosome 3 of America Abstract Oryza sativa or Asian cultivated rice is one of the major cereal grass species

Purugganan, Michael D.

117

Development of drought-resistant cultivars using physiomorphological traits in rice  

Microsoft Academic Search

Drought is a major problem for rice grown under rainfed lowland and upland conditions, but progress in breeding to improve drought resistance has been slow. This paper describes patterns of water-stress development in rice fields, reviews genetic variation in physio-morphological traits for drought resistance in rice, and suggests how knowledge of stress physiology can contribute to plant breeding programmes that

S. Fukai; M. Cooper

1995-01-01

118

Characterization of paralogous protein families in rice  

PubMed Central

Background High gene numbers in plant genomes reflect polyploidy and major gene duplication events. Oryza sativa, cultivated rice, is a diploid monocotyledonous species with a ~390 Mb genome that has undergone segmental duplication of a substantial portion of its genome. This, coupled with other genetic events such as tandem duplications, has resulted in a substantial number of its genes, and resulting proteins, occurring in paralogous families. Results Using a computational pipeline that utilizes Pfam and novel protein domains, we characterized paralogous families in rice and compared these with paralogous families in the model dicotyledonous diploid species, Arabidopsis thaliana. Arabidopsis, which has undergone genome duplication as well, has a substantially smaller genome (~120 Mb) and gene complement compared to rice. Overall, 53% and 68% of the non-transposable element-related rice and Arabidopsis proteins could be classified into paralogous protein families, respectively. Singleton and paralogous family genes differed substantially in their likelihood of encoding a protein of known or putative function; 26% and 66% of singleton genes compared to 73% and 96% of the paralogous family genes encode a known or putative protein in rice and Arabidopsis, respectively. Furthermore, a major skew in the distribution of specific gene function was observed; a total of 17 Gene Ontology categories in both rice and Arabidopsis were statistically significant in their differential distribution between paralogous family and singleton proteins. In contrast to mammalian organisms, we found that duplicated genes in rice and Arabidopsis tend to have more alternative splice forms. Using data from Massively Parallel Signature Sequencing, we show that a significant portion of the duplicated genes in rice show divergent expression although a correlation between sequence divergence and correlation of expression could be seen in very young genes. Conclusion Collectively, these data suggest that while co-regulation and conserved function are present in some paralogous protein family members, evolutionary pressures have resulted in functional divergence with differential expression patterns. PMID:18284697

Lin, Haining; Ouyang, Shu; Egan, Amy; Nobuta, Kan; Haas, Brian J; Zhu, Wei; Gu, Xun; Silva, Joana C; Meyers, Blake C; Buell, C Robin

2008-01-01

119

Microsatellite markers reveal multiple origins for Italian weedy rice  

PubMed Central

Weedy rice (Oryza sativa L.) is one of the major issues of rice cultivation worldwide. In Italy, it infests about 70% of the total rice area. Different Weedy Rice populations can be distinguished based on variable morphological and physiological traits; however, little is known about genetic differentiation and origin of Italian weedy rice populations. The objective of this study was to genetically and morphologically characterize and compare different Italian weedy rice populations selected on the basis of different phenotypes. The main Italian rice territory was divided into 10 geographical areas in which 40 weedy rice populations were collected and grouped according to the awn traits. All the individuals of the populations were morphologically characterized according to plant and seed traits. Genetic characterization was performed using 19 SSR markers on all the collected accessions, and several rice cultivars, including some very old (late 19th century), nowadays are no longer cultivated. ANOVA showed that morphological plant and seed traits were significantly affected by the collection area and awnedness group. The importance of the awn morphology was also reflected in the Bayesian clustering where, despite a relatively low genetic diversity, the clusters displayed different awn types. An UPGMA dendrogram confirmed the clusters detected in STRUCTURE analysis and also revealed a grouping of certain old cultivars with the weedy rice, suggesting a common origin. PMID:24363904

Grimm, Annabelle; Fogliatto, Silvia; Nick, Peter; Ferrero, Aldo; Vidotto, Francesco

2013-01-01

120

Insect Pest Management in Tropical Asian Irrigated Rice  

Microsoft Academic Search

Abundant natural enemies in tropical Asian irrigated rice usually pre- vent significant insect pest problems. Integrated pest management (IPM) extension education of depth and quality is required to discourage unnecessary insecticide use that upsets this natural balance, and to empower farmers as expert managers of a healthy paddy ecosystem. Farmers' skill and collaboration will be particularly impor- tant for sustainable

P. C. Matteson

2000-01-01

121

Moisture levels at which rice grains will not fissure from moisture adsorption  

E-print Network

Adsorption Effect Of Fissured Grains In Rice Processing 5 7 7 9 12 15 III MATERIALS AND METHODS 18 Equipment Systems To Produce Relative Humidity Procedures Preparation Of The Rice Samples Moisture Contents At Which Grains Will Not Fissure Rate... and head rice yields were the major causes of year to year variations in the price of rough rice. In crop production, proper cultural practices must be followed if high yields are to be realized. Effective control of pests and diseases will lead...

Kamau, John Mugeto

2012-06-07

122

Comparative analysis of panicle proteomes of two upland rice varieties upon hyper-osmotic stress  

Microsoft Academic Search

Drought is a major environmental factor that limits the yield of rice dramatically. Upland rice is now regarded as a promising\\u000a rice cultivar in water saving agriculture. Two varieties of upland rice Zhonghan 3 and IR29 were used to compare the physiological\\u000a and proteomic responses to hyper-osmotic stress induced by 15% polyethyleneglycol (PEG) at the reproductive stage. Osmotic\\u000a stress affected

Wei Huang; Ting Bi; Weining Sun

2010-01-01

123

Arctic Ecosystems  

NSDL National Science Digital Library

Scientists predict that the climate in most parts of the world will warm dramatically in the next century, with change expected to occur earliest and be most pronounced in polar regions. In light of this, there is an urgent need to understand different aspects of the Earth's climate system, including the role that Arctic ecosystems play in regulating the Earth's climate and how food webs are affected by the changing climate. This module explores the Arctic Ocean ecosystem through interaction with a model that simulates how phytoplankton and zooplankton interact and respond to changes in season, sea ice, and nutrients.

Byrd, Greg

2010-01-01

124

Proteomic changes in rice leaves during development of field-grown rice plants.  

PubMed

Of the numerous factors affecting rice yield, how solar radiation is transformed into biomass through rice leaves is the most important. We have analyzed proteomic changes in rice leaves collected from six different developing stages (vegetative to ripening). We studied protein expression profiles of rice leaves by running two-dimensional gel electrophoresis. Differential protein expression among the six phases were analyzed by image analysis, which allowed the identification of 49 significantly different gel spots. The spots were further verified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, in which 89.8% of them were confirmed to be rice proteins. Finally, we confirmed some of the interesting rice proteins by immunoblotting. Three major conclusions can be drawn from these experimental results. (i) Protein expression in rice leaves, at least for high or middle abundance proteins, is attenuated during growth (especially some chloroplast proteins). However, the change is slow and the expression profiles are relatively stable during rice development. (ii) Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), a major protein in rice leaves, is expressed at constant levels at different growth stages. Interestingly, a high ratio of degradation of the RuBisCO large subunit was found in all samples. This was confirmed by two approaches, mass spectrometry and immunoblotting. The degraded fragments are similar to other digested products of RuBisCO mediated by free radials. (iii) The expression of antioxidant proteins such as superoxide dismutase and peroxidase decline at the early ripening stage. PMID:15712239

Zhao, Caifeng; Wang, Jingqiang; Cao, Mengliang; Zhao, Kang; Shao, Jianmin; Lei, Tingting; Yin, Jianning; Hill, Gradford G; Xu, Ningzhi; Liu, Siqi

2005-03-01

125

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 47, NO. 2, FEBRUARY 2009 517 Monitoring of the Rice Cropping System in the  

E-print Network

of the world rice area (1.57 million km2 in 2007 [2]). To monitor changes in the rice production area, Thuy Le Toan, and Nguyen Lam-Dao Abstract--The rice cropping system in Asia is undergoing major changes to cope with increasing demography and changing cli- mate, making rice monitoring a critical issue. Past

Boyer, Edmond

126

Rice proteome database: a step toward functional analysis of the rice genome.  

PubMed

The technique of proteome analysis using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) has the power to monitor global changes that occur in the protein complement of tissues and subcellular compartments. In this study, the proteins of rice were cataloged, a rice proteome database was constructed, and a functional characterization of some of the identified proteins was undertaken. Proteins extracted from various tissues and subcellular compartments in rice were separated by 2D-PAGE and an image analyzer was used to construct a display of the proteins. The Rice Proteome Database contains 23 reference maps based on 2D-PAGE of proteins from various rice tissues and subcellular compartments. These reference maps comprise 13129 identified proteins, and the amino acid sequences of 5092 proteins are entered in the database. Major proteins involved in growth or stress responses were identified using the proteome approach. Some of these proteins, including a beta-tubulin, calreticulin, and ribulose-1,5-bisphosphate carboxylase/oxygenase activase in rice, have unexpected functions. The information obtained from the Rice Proteome Database will aid in cloning the genes for and predicting the function of unknown proteins. PMID:16217611

Komatsu, Setsuko

2005-09-01

127

Ecosystem type affects interpretation of soil nematode community measures  

E-print Network

Ecosystem type affects interpretation of soil nematode community measures D.A. Neher a,*, J. Wu b understanding of performance among major ecosystem types is necessary before nematode community indices can and agricultural ecosystems; (2) compare nematode community composition among and within ecosystem types and report

Neher, Deborah A.

128

Digital Ecosystems: Ecosystem-Oriented Architectures  

Microsoft Academic Search

We view Digital Ecosystems to be the digital counterparts of biological ecosystems. Here, we are concerned with the creation\\u000a of these Digital Ecosystems, exploiting the self-organising properties of biological ecosystems to evolve high-level software\\u000a applications. Therefore, we created the Digital Ecosystem, a novel optimisation technique inspired by biological ecosystems,\\u000a where the optimisation works at two levels: a first optimisation, migration

Gerard Briscoe; Suzanne Sadedin; Philippe De Wilde

2011-01-01

129

SFRSF: Our Coastal Ecosystems  

NSDL National Science Digital Library

This South Florida Restoration Science Forum (SFRSF) page highlights the coastal ecosystems of southern Florida. Research displayed from poster presentations covers the coastal area habitats, sustaining and enhancing coastal waters, major coastal challenges, restoring and enhancing estuaries, and using science for effective resource management. The six estuaries discussed are the Caloosahatchee, Southwest Florida, Biscayne Bay, Florida Bay, Florida Keys, and St. Lucie estuaries. Specific issues concerning each estuary are covered, and links are provided for additional information.

130

Standard Review Genetic engineering, ecosystem change, and agriculture: an update  

E-print Network

Genetically modified organisms (GMOs), alternatively called biotech crops, dominate soybean and cotton production and are rapidly increasing their fraction of market share for maize and rice in the U.S. Engineered canola is important in Canada, soybeans are dominant in Argentina and Brazil, and cotton is prominent in China and India. Adoption is much slower elsewhere, in large part due to concerns for potential ecosystem effects that may occur through development of weedy plants, by selection of herbicide resistant weeds and by effects of insecticidal proteins on nontarget insects. The precautionary principle is invoked by critics concerned that one must know in advance the effects of GMOs before releasing them. Alteration of weed species composition of agricultural fields is well documented to occur under herbicide selection pressure. Gene flow to wild relatives of crop plants can be shown under herbicide selection, and one instance (sunflower) is provided for insect resistance transfer leading to increased seed production by a weedy relative. Detailed stewardship programs have been developed by seed producers to minimize risks of gene flow. Although herbicides and insecticides are known to have major effects on agroecosystems, the ecosystem impacts of GMOs per se, thus far appear to be small.

Lawrence C. Davis

2006-01-01

131

rice boulevard Tennis Stadium  

E-print Network

rice boulevard Jake Hess Tennis Stadium Reckling Park Tennis Courts Practice Field Intramural Field Hess Tennis Stadium, Jake ............34 Holloway Field .................................35 Wendel D

Richards-Kortum, Rebecca

132

The use of rice seeds to produce human pharmaceuticals for oral therapy.  

PubMed

Rice (Oryza sativa L.) is the major staple food consumed by half of the world's population. Rice seeds have gained recent attention as bioreactors for the production of human pharmaceuticals such as therapeutic proteins or peptides. Rice seed production platforms have many advantages over animal cell or microbe systems in terms of cost-effectiveness, scalability, safety, product stability and productivity. Rice seed-based human pharmaceuticals are expected to become innovative therapies as edible drugs. Therapeutic proteins can be sequestered within natural cellular compartments in rice seeds and protected from harsh gastrointestinal environments. This review presents the state-of-the-art on the construction of gene cassettes for accumulation of pharmaceutical proteins or peptides in rice seeds, the generation of transgenic rice plants, and challenges involved in the use of rice seeds to produce human pharmaceuticals. PMID:24092672

Wakasa, Yuhya; Takaiwa, Fumio

2013-10-01

133

The Impact of Herbicide-Resistant Rice Technology on Phenotypic Diversity and Population Structure of United States Weedy Rice1[W][OPEN  

PubMed Central

The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. PMID:25122473

Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D.; Huang, Zhongyun; Hyma, Katie E.; Gealy, David R.; Caicedo, Ana L.

2014-01-01

134

Fat-soluble bioactive components in colored rice varieties.  

PubMed

Abstract Bioactive components in rice vary depending on the variety and growing condition. Fat-soluble components such as ?-oryzanol, tocopherols, tocotrienols, carotenoids, and fatty acids were analyzed in brown, sugary brown, red, and black rice varieties using established high-performance liquid chromatography (HPLC) and GC methodologies. In addition, these colored rice varieties were further analyzed using a high-resolution liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) (LTQ-Orbitrap XL) to identify the [M-H](-) ions of ?-oryzanol, ranging from m/z 573.3949 to 617.4211. The highest content of tocopherols (?-, 1.5; ?-, 0.5?mg/100?g) and carotenoids (lutein 244; trans-? carotene 25 ?g/100?g) were observed in black rice; tocotrienols (?-, 0.07; ?-, 0.14?mg/100?g) in red rice, and ?-oryzanol (115?mg/100?g) in sugary brown rice. In all colored rice varieties, the major fatty acids were palmitic (16:0), oleic (18:1n-9), and linoleic (18:2n-6) acids. When the ?-oryzanol components were further analyzed by LC-MS/MS, 3, 10, 8, and 8 triterpene alcohols or sterol ferulates were identified in brown, sugary brown, red, and black rice varieties, respectively. Such structural identification can lead to the elucidation of biological function of each component at the molecular level. Consumption of colored rice rich in beneficial bioactive compounds may be a useful dietary strategy for achieving optimal health. PMID:25162990

Minatel, Igor Otavio; Han, Sang-Ik; Aldini, Giancarlo; Colzani, Mara; Matthan, Nirupa R; Correa, Camila Renata; Fecchio, Denise; Yeum, Kyung-Jin

2014-10-01

135

Marine Ecosystems  

NSDL National Science Digital Library

In the wild, small crustaceans known as brine shrimp live in marine habitats such as saltwater lakes. In this activity, learners create a saltwater or marine ecosystem that becomes an experimental brine shrimp hatchery. Learners observe the brine shrimp life cycle and test the effect of salinity (salt content) on brine shrimp eggs and larvae, as well as consider the potential impact of other variables such as water temperature and pollution.

Jersey, New; Center, Liberty S.; Coalition, New J.

2006-01-01

136

Long-Term Ecosystem Response to the Exxon Valdez Oil Spill  

E-print Network

Long-Term Ecosystem Response to the Exxon Valdez Oil Spill Charles H. Peterson,1 * Stanley D. Rice The ecosystem response to the 1989 spill of oil from the Exxon Valdez into Prince William Sound, Alaska, shows long-term risks and impacts. B efore the Exxon Valdez oil spill, infor- mation available

137

Diversity of Global Rice Markets and the Science Required for Consumer-Targeted Rice Breeding  

PubMed Central

With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a ‘one size fits all’ crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market. PMID:24454799

Calingacion, Mariafe; Laborte, Alice; Nelson, Andrew; Resurreccion, Adoracion; Concepcion, Jeanaflor Crystal; Daygon, Venea Dara; Mumm, Roland; Reinke, Russell; Dipti, Sharifa; Bassinello, Priscila Zaczuk; Manful, John; Sophany, Sakhan; Lara, Karla Cordero; Bao, Jinsong; Xie, Lihong; Loaiza, Katerine; El-hissewy, Ahmad; Gayin, Joseph; Sharma, Neerja; Rajeswari, Sivakami; Manonmani, Swaminathan; Rani, N. Shobha; Kota, Suneetha; Indrasari, Siti Dewi; Habibi, Fatemeh; Hosseini, Maryam; Tavasoli, Fatemeh; Suzuki, Keitaro; Umemoto, Takayuki; Boualaphanh, Chanthkone; Lee, Huei Hong; Hung, Yiu Pang; Ramli, Asfaliza; Aung, Pa Pa; Ahmad, Rauf; Wattoo, Javed Iqbal; Bandonill, Evelyn; Romero, Marissa; Brites, Carla Moita; Hafeel, Roshni; Lur, Huu-Sheng; Cheaupun, Kunya; Jongdee, Supanee; Blanco, Pedro; Bryant, Rolfe; Thi Lang, Nguyen; Hall, Robert D.; Fitzgerald, Melissa

2014-01-01

138

Diversity of global rice markets and the science required for consumer-targeted rice breeding.  

PubMed

With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a 'one size fits all' crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market. PMID:24454799

Calingacion, Mariafe; Laborte, Alice; Nelson, Andrew; Resurreccion, Adoracion; Concepcion, Jeanaflor Crystal; Daygon, Venea Dara; Mumm, Roland; Reinke, Russell; Dipti, Sharifa; Bassinello, Priscila Zaczuk; Manful, John; Sophany, Sakhan; Lara, Karla Cordero; Bao, Jinsong; Xie, Lihong; Loaiza, Katerine; El-hissewy, Ahmad; Gayin, Joseph; Sharma, Neerja; Rajeswari, Sivakami; Manonmani, Swaminathan; Rani, N Shobha; Kota, Suneetha; Indrasari, Siti Dewi; Habibi, Fatemeh; Hosseini, Maryam; Tavasoli, Fatemeh; Suzuki, Keitaro; Umemoto, Takayuki; Boualaphanh, Chanthkone; Lee, Huei Hong; Hung, Yiu Pang; Ramli, Asfaliza; Aung, Pa Pa; Ahmad, Rauf; Wattoo, Javed Iqbal; Bandonill, Evelyn; Romero, Marissa; Brites, Carla Moita; Hafeel, Roshni; Lur, Huu-Sheng; Cheaupun, Kunya; Jongdee, Supanee; Blanco, Pedro; Bryant, Rolfe; Thi Lang, Nguyen; Hall, Robert D; Fitzgerald, Melissa

2014-01-01

139

Legislation Affecting the Rice Industry, 1933-56.  

E-print Network

. ment in the national economy. This publication reviews major legislation pertaining to rice since the 1933 Agriculture Adjust- ment Act. It cites the major legislative actions taken by the government toward establishing a level of income to rice..., surplus supplies totaled slightly ( over 7 billion pounds from August 1, 1953 to August 1, 1955. The carryover on August 1, 1955 was 23 ' times greater than the carryover of 150 million pounds on August 1, 1952. I The 1956 Agriculture Act represents...

Kincannon, John A.

1956-01-01

140

Characterization of paralogous protein families in rice  

Microsoft Academic Search

BACKGROUND: High gene numbers in plant genomes reflect polyploidy and major gene duplication events. Oryza sativa, cultivated rice, is a diploid monocotyledonous species with a ~390 Mb genome that has undergone segmental duplication of a substantial portion of its genome. This, coupled with other genetic events such as tandem duplications, has resulted in a substantial number of its genes, and

Haining Lin; Shu Ouyang; Amy Egan; Kan Nobuta; Brian J Haas; Wei Zhu; Xun Gu; Joana C Silva; Blake C Meyers; C Robin Buell

2008-01-01

141

Project RICE (Responsive Inner City Education).  

ERIC Educational Resources Information Center

Project RICE (Responsive Inner City Education) prepared a cadre of 36 teachers drawn from majority and minority populations in 3 inner-city schools in Buffalo (New York) to complement mastery of subject matter with appropriate pedagogical styles. The project was designed to test the hypothesis that minority students in inner-city schools do not…

Mattai, P. Rudy

142

Rice University General Announcements  

E-print Network

, to correctorotherwisechangeanyinformationwithoutnotice.Amorerecentversion of this publication is available on the university's website. The information opportunity in education and employment. It is the policy of Rice University to attract qualified individuals of diverse backgrounds to its faculty, staff, and student body. Rice University does not discriminate against

Richards-Kortum, Rebecca

143

Fine-mapping of qRL6.1, a major QTL for root length of rice seedlings grown under a wide range of NH4+ concentrations in hydroponic conditions  

PubMed Central

Root system development is an important target for improving yield in cereal crops. Active root systems that can take up nutrients more efficiently are essential for enhancing grain yield. In this study, we attempted to identify quantitative trait loci (QTL) involved in root system development by measuring root length of rice seedlings grown in hydroponic culture. Reliable growth conditions for estimating the root length were first established to renew nutrient solutions daily and supply NH4+ as a single nitrogen source. Thirty-eight chromosome segment substitution lines derived from a cross between ‘Koshihikari’, a japonica variety, and ‘Kasalath’, an indica variety, were used to detect QTL for seminal root length of seedlings grown in 5 or 500 ?M NH4+. Eight chromosomal regions were found to be involved in root elongation. Among them, the most effective QTL was detected on a ‘Kasalath’ segment of SL-218, which was localized to the long-arm of chromosome 6. The ‘Kasalath’ allele at this QTL, qRL6.1, greatly promoted root elongation under all NH4+ concentrations tested. The genetic effect of this QTL was confirmed by analysis of the near-isogenic line (NIL) qRL6.1. The seminal root length of the NIL was 13.5–21.1% longer than that of ‘Koshihikari’ under different NH4+ concentrations. Toward our goal of applying qRL6.1 in a molecular breeding program to enhance rice yield, a candidate genomic region of qRL6.1 was delimited within a 337 kb region in the ‘Nipponbare’ genome by means of progeny testing of F2 plants/F3 lines derived from a cross between SL-218 and ‘Koshihikari’. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1328-3) contains supplementary material, which is available to authorized users. PMID:20390245

Tamura, Wataru; Ebitani, Takeshi; Yano, Masahiro; Sato, Tadashi; Yamaya, Tomoyuki

2010-01-01

144

Rice bran: a novel functional ingredient.  

PubMed

Rice (Oryza sativa) is the most important staple food for a large part of the world's human population, especially in East and South Asia, the Middle East, Latin America, and the West Indies. It provides more than one fifth of the calories consumed worldwide by the human. It is the second leading cereal crop and staple food of half of the world's population. It is grown in at least 114 countries with global production of 645 million tons; share of Asian farmers is about 90% of the total produce. Rice bran, brown outer layer of rice kernel, is mainly composed of pericarp, aleurone, subaleurone layer, and germ. It contains appreciable quantities of nutrients like protein, fat, and dietary fiber. Furthermore, it contains substantial amount of minerals like K, Ca, Mg, and Fe. Presence of antioxidants like tocopherols, tocotrienols, and ?-oryzanol also brighten prospects of rice bran utilization for humans as functional ingredient to mitigate the life-threatening disorders. Moreover, in the developing countries, budding dilemma of food crisis, arising due to lower crop yields and escalating population, needs to utilize each pent of available resources. To provide enough food to all people, there is the holistic approach of using the by-products generated during food processing and preparations. Rice is being processed in well-established industry, but the major apprehension is the utilization of its by-products; rice bran (5-8%) and polishing (2-3%) that are going as waste. Rice processing or milling produces several streams of materials including milled rice, bran, and husk. In developing countries, rice bran is considered as a by-product of the milling process and commonly used in animal feed or discarded as a waste. The potential of producing rice bran at the global level is 29.3 million tons annually, whereas the share of Pakistan is worked out to be 0.5 million tons. In present paper, attempt has been made to highlight the significance of these valuable but neglected ingredients under various headings. PMID:24345050

Sharif, Mian Kamran; Butt, Masood Sadiq; Anjum, Faqir Muhammad; Khan, Saima Hafiz

2014-01-01

145

The LANSCE RICE Control System Upgrade.  

SciTech Connect

The LANSCE (Los Alamos Neutron Science Center) control system upgrade program continues with the impending replacement of the RICE (Remote Instrumentation and Control Equipment) subsystem. The RICE subsystem upgrade is a challenge because of its technology (late 1960’s), number of channels (>10,000), and unique characteristics (all-modules data takes, timed/flavored data takes). The plan is to replace at least the non-timed data and the command portions of the subsystem with Programmable Logic Controllers (PLCs). We discuss motivations, technological challenges, proofof- principle, and planning. The boundary condition, as usual, is that we must implement these major changes on a running accelerator.

Oothoudt, Michael; Bjorklund, Eric; Burns, Mary; Carr, Gary; Faucett, John; Hayden, David; Lusk, Matthew; Merl, Robert; Potter, Jerry; Reynolds, Jerome; Romero, Dolores

2003-04-24

146

The LANSCE RICE control system upgrade.  

SciTech Connect

The LANSCE (Los Alamos Neutron Science Center) control system upgrade program continues with the impending replacement of the RICE (Remote Instrumentation and Control Equipment) subsystem. The RICE subsystem upgrade is a challenge because of its technology (late 1960s), number of channels (>10,000), and unique characteristics (all-modules data takes, timed/flavored data takes). The plan is to replace at least the non-timed data and the command portions of the subsystem with Programmable Logic Controllers (PLCs). We discuss motivations, technological challenges, proof-of-principle, and planning. The boundary condition, as usual, is that we must implement these major changes on a running accelerator.

Oothoudt, Michael; Schaller, S. (Stuart); Bjorklund, E. A. (Eric A.); Burns, M. J. (Mary J.); Carr, G. (Gary); Carr, G. (Gary); Faucett, John Allen,; Hayden, D. J. (David J.); Lusk, M. D. (Matthew D.); Merl, R. B. (Robert B.); Potter, J. M. (Jerry M.); Reynolds, J. A. (Jerome A.); Romero, D. B. (Dolores B.); Shelley, F. E. (Fred E.)

2003-01-01

147

Actual and potential salt-related soil degradation in an irrigated rice scheme in the Sahelian zone of Mauritania  

Microsoft Academic Search

Salt-related soil degradation due to irrigation activities is considered a major threat to the sustainability of rice cropping under semi-arid conditions in West Africa. Rice productivity problems related to soil salinity, alkalinity and topographic position were observed in an irrigated rice scheme in southern central Mauritania. Detailed study of soils in a toposequence revealed that highest topsoil salinity and alkalinity

Asten van P. J. A; L. Barbi'ro; M. C. S. Wopereis; J. L. Maeght; Zee van der S. E. A. T. M

2003-01-01

148

Climate change: implications for the yield of edible rice.  

PubMed

Global warming affects not only rice yield but also grain quality. A better understanding of the effects of climate factors on rice quality provides information for new breeding strategies to develop varieties of rice adapted to a changing world. Chalkiness is a key trait of physical quality, and along with head rice yield, is used to determine the price of rice in all markets. In the present study, we show that for every ?1% decrease in chalkiness, an increase of ?1% in head rice yield follows, illustrating the dual impact of chalk on amount of marketable rice and its value. Previous studies in controlled growing conditions report that chalkiness is associated with high temperature. From 1980-2009 at IRRI, Los Baños, the Philippines, annual minimum and mean temperatures, and diurnal variation changed significantly. The objective of this study was to determine how climate impacts chalkiness in field conditions over four wet and dry seasons. We show that low relative humidity and a high vapour pressure deficit in the dry season associate with low chalk and high head rice yield in spite of higher maximum temperature, but in the opposite conditions of the wet season, chalk is high and head rice yield is low. The data therefore suggest that transpirational cooling is a key factor affecting chalkiness and head rice yield, and global warming per se might not be the major factor that decreases the amount and quality of rice, but other climate factors in combination, that enable the crop to maintain a cool canopy. PMID:23776635

Zhao, Xiangqian; Fitzgerald, Melissa

2013-01-01

149

Rice transgene flow: its patterns, model and risk management.  

PubMed

Progress has been made in a 12 year's systemic study on the rice transgene flow including (i) with experiments conducted at multiple locations and years using up to 21 pollen recipients, we have elucidated the patterns of transgene flow to different types of rice. The frequency to male sterile lines is 10(1) and 10(3) higher than that to O. rufipogon and rice cultivars. Wind speed and direction are the key meteorological factors affecting rice transgene flow. (ii) A regional applicable rice gene flow model is established and used to predict the maximum threshold distances (MTDs) of gene flow during 30 years in 993 major rice producing counties of southern China. The MTD0.1% for rice cultivars is basically ?5 m in the whole region, despite climate differs significantly at diverse locations and years. This figure is particularly valuable for the commercialization and regulation of transgenic rice. (iii) The long-term fate of transgene integrated into common wild rice was investigated. Results demonstrated that the F1 hybrids of transgenic rice/O. rufipogon gradually disappeared within 3-5 years, and the Bt or bar gene was not detectable in the mixed population, suggesting the O. rufipogon may possess a strong mechanism of exclusiveness for self-protection. (iv) The flowering time isolation and a 2-m-high cloth-screen protection were proved to be effective in reducing transgene flow. We have proposed to use a principle of classification and threshold management for different types of rice. PMID:25431202

Jia, Shirong; Yuan, Qianhua; Pei, Xinwu; Wang, Feng; Hu, Ning; Yao, Kemin; Wang, Zhixing

2014-12-01

150

Leadership Rice The mission of Leadership Rice is to help Rice University undergraduates from  

E-print Network

189 Leadership Rice The mission of Leadership Rice is to help Rice University undergraduates from all disciplines build their leadership capacities to create and manage change ef- fectively. Leadership Rice explores how heart and mind, theory and practice, and ideas and actions come together

Richards-Kortum, Rebecca

151

Leadership Rice Leadership Rice exists to encourage and equip Rice students to obtain  

E-print Network

Leadership Rice Leadership Rice exists to encourage and equip Rice students to obtain leadership roles at Rice and beyond. We provide leadership development opportunities to undergraduates from every ambition for leadership. We seek to accomplish our mission through a blend of curricular and co

Richards-Kortum, Rebecca

152

Methylated arsenic species in rice: geographical variation, origin, and uptake mechanisms.  

PubMed

Rice is a major source of inorganic arsenic (iAs) in the human diet because paddy rice is efficient at accumulating As. Rice As speciation is dominated by iAs and dimethylarsinic acid (DMA). Here we review the global pattern in rice As speciation and the factors causing the variation. Rice produced in Asia shows a strong linear relationship between iAs and total As concentration with a slope of 0.78. Rice produced in Europe and the United States shows a more variable, but generally hyperbolic relationship with DMA being predominant in U.S. rice. Although there is significant genotypic variation in grain As speciation, the regional variations are primarily attributed to environmental factors. Emerging evidence also indicates that methylated As species in rice are derived from the soil, while rice plants lack the As methylation ability. Soil flooding and additions of organic matter increase microbial methylation of As, although the microbial community responsible for methylation is poorly understood. Compared with iAs, methylated As species are taken up by rice roots less efficiently but are transported to the grain much more efficiently, which may be an important factor responsible for the spikelet sterility disorder (straight-head disease) in rice. DMA is a weak carcinogen, but the level of ingestion from rice consumption is much lower than that of concern. Questions that require further investigations are identified. PMID:23521218

Zhao, Fang-Jie; Zhu, Yong-Guan; Meharg, Andrew A

2013-05-01

153

Soil respiration, labile carbon pools, and enzyme activities as affected by tillage practices in a tropical rice-maize-cowpea cropping system.  

PubMed

In order to identify the viable option of tillage practices in rice-maize-cowpea cropping system that could cut down soil carbon dioxide (CO2) emission, sustain grain yield, and maintain better soil quality in tropical low land rice ecology soil respiration in terms of CO2 emission, labile carbon (C) pools, water-stable aggregate C fractions, and enzymatic activities were investigated in a sandy clay loam soil. Soil respiration is the major pathway of gaseous C efflux from terrestrial systems and acts as an important index of ecosystem functioning. The CO2-C emissions were quantified in between plants and rows throughout the year in rice-maize-cowpea cropping sequence both under conventional tillage (CT) and minimum tillage (MT) practices along with soil moisture and temperature. The CO2-C emissions, as a whole, were 24 % higher in between plants than in rows, and were in the range of 23.4-78.1, 37.1-128.1, and 28.6-101.2 mg m(-2) h(-1) under CT and 10.7-60.3, 17.3-99.1, and 17.2-79.1 mg m(-2) h(-1) under MT in rice, maize, and cowpea, respectively. The CO2-C emission was found highest under maize (44 %) followed by rice (33 %) and cowpea (23 %) irrespective of CT and MT practices. In CT system, the CO2-C emission increased significantly by 37.1 % with respect to MT on cumulative annual basis including fallow. The CO2-C emission per unit yield was at par in rice and cowpea signifying the beneficial effect of MT in maintaining soil quality and reduction of CO2 emission. The microbial biomass C (MBC), readily mineralizable C (RMC), water-soluble C (WSC), and permanganate-oxidizable C (PMOC) were 19.4, 20.4, 39.5, and 15.1 % higher under MT than CT. The C contents in soil aggregate fraction were significantly higher in MT than CT. Soil enzymatic activities like, dehydrogenase, fluorescein diacetate, and ?-glucosidase were significantly higher by 13.8, 15.4, and 27.4 % under MT compared to CT. The soil labile C pools, enzymatic activities, and heterotrophic microbial populations were in the order of maize?>?cowpea?>?rice, irrespective of the tillage treatments. Environmental sustainability point of view, minimum tillage practices in rice-maize-cowpea cropping system in tropical low land soil could be adopted to minimize CO2-C emission, sustain yield, and maintain soil health. PMID:24609455

Neogi, S; Bhattacharyya, P; Roy, K S; Panda, B B; Nayak, A K; Rao, K S; Manna, M C

2014-07-01

154

Introducing non-flooded crops in rice-dominated landscapes: Impact on carbon, nitrogen and water budgets  

NASA Astrophysics Data System (ADS)

Rice production consumes about 30% of all freshwater used worldwide and 45% in Asia. Turning away from permanently flooded rice cropping systems for mitigating future water scarcity and reducing methane emissions, however, will alter a variety of ecosystem services with potential adverse effects to both the environment and agricultural production. Moreover, implementing systems that alternate between flooded and non-flooded crops increases the risk of disruptive effects. The multi-disciplinary DFG research unit ICON aims at exploring and quantifying the ecological consequences of altered water regimes (flooded vs. non-flooded), crop diversification (irrigated rice vs. aerobic rice vs. maize), and different fertilization strategies (conventional, site-specific, and zero N fertilization). ICON particularly focuses on the biogeochemical cycling of carbon and nitrogen, green-house gas (GHG) emissions, water balance, soil biotic processes and other important ecosystem services. The overarching goal is to provide the basic process understanding that is necessary for balancing the revenues and environmental impacts of high-yield rice cropping systems while maintaining their vital ecosystem services. To this aim, a large-scale field experiment has been established at the experimental farm of the International Rice Research Institute (IRRI, Philippines). Ultimately, the experimental results are analyzed in the context of management scenarios by an integrated modeling of crop development (ORYZA), carbon and nitrogen cycling (MoBiLE-DNDC), and water fluxes (CMF), providing the basis for developing pathways to a conversion of rice-based systems towards higher yield potentials under minimized environmental impacts. In our presentation, we demonstrate the set-up of the controlled large-scale field experiment for simultaneous assessment of carbon and nitrogen fluxes and water budgets. We show and discuss first results for: - Quantification and assessment of the net-fluxes of CH4, N2O and CO2 from rice-rice and rice-maize rotations. The conversion of flooded to non-flooded cropping systems resulted in pollution swapping of greenhouse gas emissions, shifting from CH4 under wet conditions to N2O under dry conditions. - Quantification and assessment of water budgets and nutrient loss in rice-rice and rice-maize rotations. Switching from rice-rice dominated growing systems to upland rice or maize-rice cropping systems resulted in reduced water use efficiency and increased nitrogen loss. - Quantification and assessment of soil functions affected by soil fauna community structure in flooded and non-flooded cropping rotations. In contrast to temperate soils, earthworms reduced the peaks of microbial C and N decomposition depending on soil water content.

Jauker, Frank; Wassmann, Reiner; Amelung, Wulf; Breuer, Lutz; Butterbach-Bahl, Klaus; Conrad, Ralf; Ekschmitt, Klemens; Goldbach, Heiner; He, Yao; John, Katharina; Kiese, Ralf; Kraus, David; Reinhold-Hurek, Barbara; Siemens, Jan; Weller, Sebastian; Wolters, Volkmar

2013-04-01

155

Effect of Rice Cultivation Systems on Indigenous Arbuscular Mycorrhizal Fungal Community Structure  

PubMed Central

Arbuscular mycorrhizal fungi (AMF) in an agricultural ecosystem are necessary for proper management of beneficial symbiosis. Here we explored how the patterns of the AMF community in rice roots were affected by rice cultivation systems (the system of rice intensification [SRI] and the conventional rice cultivation system [CS]), and by compost application during growth stages. Rice plants harvested from SRI-managed plots exhibited considerably higher total biomass, root dry weight, and seed fill than those obtained from conventionally managed plots. Our findings revealed that all AMF sequences observed from CS plots belonged (only) to the genus Glomus, colonizing in rice roots grown under this type of cultivation, while rice roots sown in SRI showed sequences belonging to both Glomus and Acaulospora. The AMF community was compared between the different cultivation types (CS and SRI) and compost applications by principle component analysis. In all rice growth stages, AMF assemblages of CS management were not separated from those of SRI management. The distribution of AMF community composition based on T-RFLP data showed that the AMF community structure was different among four cultivation systems, and there was a gradual increase of Shannon-Weaver indices of diversity (H?) of the AMF community under SRI during growth stages. The results of this research indicated that rice grown in SRI-managed plots had more diverse AMF communities than those grown in CS plots. PMID:23719585

Watanarojanaporn, Nantida; Boonkerd, Nantakorn; Tittabutr, Panlada; Longtonglang, Aphakorn; Young, J. Peter W.; Teaumroong, Neung

2013-01-01

156

Modeling the rice phenology and production in China with SIMRIW: sensitivity analysis and parameter estimation  

NASA Astrophysics Data System (ADS)

Crop models are robust tools for simulating the impact of climate change on rice development and production, but are usually designed for specific stations and varieties. This study focuses on a more adaptable model called Simulation Model for Rice-Weather Relations (SIMRIW). The model was calibrated and validated in major rice production regions over China, and the parameters that most affect the model's output were determined in sensitivity analyses. These sensitive parameters were estimated in different ecological zones. The simulated results of single and double rice cropping systems in different ecological zones were then compared. The accuracy of SIMRIW was found to depend on a few crucial parameters. Using optimized parameters, SIMRIW properly simulated the rice phenology and yield in single and double cropping systems in different ecological zones. Some of the parameters were largely dependent on ecological zone and rice type, and may reflect the different climate conditions and rice varieties among ecological zones.

Zhang, Shuai; Tao, Fulu; Shi, Runhe

2014-11-01

157

The Potential of Polarimetric and Compact SAR Data in Rice Identification  

NASA Astrophysics Data System (ADS)

Rice is a major food staple in the world, and provides food for more than one-third of the global population. The monitoring and mapping of paddy rice in a timely and efficient manner is very important for governments and decision makers. Synthetic Aperture Radar (SAR) has been proved to be a significant data source in rice monitoring. In this study, RADARSAT-2 polarimetric data were used to simulate compact polarimetry data. The simulated compact data and polarimetric data were then used to evaluate the information content for rice identification. The results indicate that polarimetric SAR can be used for rice identification based on the scattering mechanisms. The compact polarization RH and the RH/RL ratio are very promising for the discrimination of transplanted rice and direct-sown rice. These results require verification in further research.

Shao, Y.; Li, K.; Brisco, B.; Liu, L.; Yang, Z.

2014-03-01

158

Herbivory by resident geese: The loss and recovery of wild rice along the tidal Patuxent River  

USGS Publications Warehouse

Well known for a fall spectacle of maturing wild rice (Zizania aquatica) and migrant waterbirds, the tidal freshwater marshes of the Patuxent River, Maryland, USA, experienced a major decline in wild rice during the 1990s. We conducted experiments in 1999 and 2000 with fenced exclosures and discovered herbivory by resident Canada geese (Branta canadensis). Grazing by geese eliminated rice outside exclosures, whereas protected plants achieved greater size, density, and produced more panicles than rice occurring in natural stands. The observed loss of rice on the Patuxent River reflects both the sensitivity of this annual plant to herbivory and the destructive nature of an overabundance of resident geese on natural marsh vegetation. Recovery of rice followed 2 management actions: hunting removal of approximately 1,700 geese during a 4-year period and reestablishment of rice through a large-scale fencing and planting program.

Haramis, G. M.; Kearns, G.D.

2007-01-01

159

Terrestrial Ecosystem Adaptation  

E-print Network

Terrestrial Ecosystem Adaptation Steven W. Running and L. Scott Mills RFF REPORT ............................... 16 Expected Future Ecosystem Trends ................................................................................................................................................................ 27 #12; RUNNING AND MILLS 1 Terrestrial Ecosystem Adaptation Steven W. Running and L. Scott

Mills, L. Scott

160

Measuring the Human Footprint on Ecosystem Function  

Microsoft Academic Search

Major questions for the biogeosciences concern the consequences of human transformation of landscapes for biogeochemical cycling and other ecosystem functions. While it is clear that the footprint of humans extends to almost all corners of the world, there is no single measure of the anthropogenic effect on ecosystems. Unlike the \\

R. S. DeFries

2001-01-01

161

The Belgian sandy beach ecosystem: a review  

Microsoft Academic Search

This paper reviews the available knowledge on sedimentology, hydrodynamics and five major ecosystem components (microphytobenthos, vascular plants, terrestrial arthropods, zoobenthos, and avifauna) of Belgian sandy beaches. It covers the area from the foredunes to the lower foreshore, takes an ecosystem approach to beaches of this specific geographic area. Morphodynamically, Bel- gian beaches are (ultra-)dissipative, macrotidal, and wide. Characteristic grain sizes

Jeroen Speybroeck; Dries Bonte; Wouter Courtens; Tom Gheskiere; Patrick Grootaert; Jean-Pierre Maelfait; Sam Provoost; Koen Sabbe; Eric W. M. Stienen; Vera Van Lancker; Wouter Van Landuyt; Magda Vincx; Steven Degraer

2008-01-01

162

Weed Management in Rice?Based Cropping Systems in Africa  

Microsoft Academic Search

Weed competition is a major constraint in all the rice production systems in Africa. In addition to the costs of weed control, weeds account for yield losses estimated to be at least 2.2 million tons per year in sub?Saharan Africa, valued at $1.45 billion, and equating to approximately half the current total imports of rice to this region. Important weeds

J. Rodenburg; D. E. Johnson

2009-01-01

163

Leadership Rice The mission of Leadership RiceistohelpRiceUniversityundergraduates  

E-print Network

189 Leadership Rice The mission of Leadership RiceistohelpRiceUniversityundergraduates fromalldisciplinesbuildtheirleadershipcapacitiestocreateandmanage changeeffectively.LeadershipRiceexploreshowheartandmind,theoryand practice,andideasandactionscometogethertofacilitatechange. Theintroductorycourse,LEAD309Leadership: Theory to Practice (formerly UNIV309),isrequiredtoapplyforparticipationinthe

Richards-Kortum, Rebecca

164

Resequencing rice genomes: an emerging new era of rice genomics.  

PubMed

Rice is a model system for crop genomics studies. Much of the early work on rice genomics focused on analyzing genome-wide genetic variation to further understand rice gene functions in agronomic traits and to generate data and resources for rice research. The advent of next-generation high-throughput DNA sequencing technologies and the completion of high-quality reference genome sequences have enabled the development of sequencing-based genotyping and genome-wide association studies (GWAS) that have significantly advanced rice genetics research. This has led to the emergence of a new era of rice genomics aimed at bridging the knowledge gap between genotype and phenotype in rice. These technologies have also led to pyramid breeding through genomics-assisted selection, which will be useful in breeding elite varieties suitable for sustainable agriculture. Here, we review the recent advances in rice genomics and discuss the future of this line of research. PMID:23295340

Huang, Xuehui; Lu, Tingting; Han, Bin

2013-04-01

165

What it will take to feed 5.0 billion rice consumers in 2030.  

PubMed

Major advances have occurred in rice production due to adoption of green revolution technology. Between 1966 and 2000, the population of densely populated low income countries grew by 90% but rice production increased by 130% from 257 million tons in 1966 to 600 million tons in 2000. However, the population of rice consuming countries continues to grow and it is estimated that we will have to produce 40 more rice in 2030. This increased demand will have to be met from less land, with less water, less labor and fewer chemicals. To meet the challenge of producing more rice from suitable lands we need rice varieties with higher yield potential and greater yield stability. Various strategies for increasing the rice yield potential being employed include: (1) conventional hybridization and selection procedures, (2) ideotype breeding, (3) hybrid breeding, (4) wide hybridization and (5) genetic engineering. Various conventional and biotechnology approach are being employed to develop durable resistance to diseases and insect and for tolerance to abiotic stresses. The availability of the rice genome sequence will now permit identification of the function of each of 60,000 rice genes through functional genomics. Once the function of a gene is identified, it will be possible to develop new rice varieties by introduction of the gene through traditional breeding in combination with marker aided selection or direct engineering of genes into rice varieties. PMID:16217597

Khush, Gurdev S

2005-09-01

166

Astronomical Ecosystems  

NASA Astrophysics Data System (ADS)

Just as quetzals and jaguars require specific ecological habitats to survive, so too must planets occupy a tightly constrained astronomical habitat to support life as we know it. With this theme in mind we relate the transferable features of our elementary astronomy course, "The Astronomical Basis of Life on Earth." Over the last five years, in a team-taught course that features a spring break field trip to Costa Rica, we have introduced astronomy through "astronomical ecosystems," emphasizing astronomical constraints on the prospects for life on Earth. Life requires energy, chemical elements, and long timescales, and we emphasize how cosmological, astrophysical, and geological realities, through stabilities and catastrophes, create and eliminate niches for biological life. The linkage between astronomy and biology gets immediate and personal: for example, studies in solar energy production are followed by hikes in the forest to examine the light-gathering strategies of photosynthetic organisms; a lesson on tides is conducted while standing up to our necks in one on a Pacific beach. Further linkages between astronomy and the human timescale concerns of biological diversity, cultural diversity, and environmental sustainability are natural and direct. Our experience of teaching "astronomy as habitat" strongly influences our "Astronomy 101" course in Oklahoma as well. This "inverted astrobiology" seems to transform our student's outlook, from the universe being something "out there" into something "we're in!" We thank the SNU Science Alumni support group "The Catalysts," and the SNU Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica, for their support.

Neuenschwander, D. E.; Finkenbinder, L. R.

2004-05-01

167

ECOSYSTEM ECOLOGY -ORIGINAL PAPER Increasing donor ecosystem productivity decreases terrestrial  

E-print Network

ECOSYSTEM ECOLOGY - ORIGINAL PAPER Increasing donor ecosystem productivity decreases terrestrial Abstract Because nutrient enrichment can increase ecosystem productivity, it may enhance resource flows to adjacent ecosystems as organisms cross ecosystem bound- aries and subsidize predators in recipient

Rosemond, Amy Daum

168

Rice University Department of Bioengineering  

E-print Network

Page | 1 Rice University Department of Bioengineering Graduate Degree Requirements.D./Ph.D. is offered between the Rice Department of Bioengineering and Baylor College of Medicine. Few students ...............................................................................8 J. Acceptance of Thesis

Richards-Kortum, Rebecca

169

A draft sequence of the rice ( Oryza sativa ssp. indica ) genome  

Microsoft Academic Search

The sequence of the rice genome holds fundamental information for its biology, including physiology, genetics, development,\\u000a and evolution, as well as information on many beneficial phenotypes of economic significance. Using a “whole genome shotgun”\\u000a approach, we have produced a draft rice genome sequence ofOryza sativa ssp.indica, the major crop rice subspecies in China and many other regions of Asia. The

Jun Yu; Songnian Hu; Jun Wang; Songgang Li; Ka-Shu Gane Wong; Bin Liu; Yajun Deng; Li Dai; Yan Zhou; Xiuqing Zhang; Mengliang Cao; Jing Liu; Jiandong Sun; Jiabin Tang; Yanjiong Chen; Xiaobing Huang; Wei Lin; Chen Ye; Wei Tong; Lijuan Cong; Jianing Geng; Yujun Han; Lin Li; Wei Li; Guangqiang Hu; Xiangang Huang; Wenjie Li; Jian Li; Zhanwei Liu; Long Li; Jianping Liu; Qiuhui Qi; Jinsong Liu; Li Li; Xuegang Wang; Hong Lu; Tingting Wu; Miao Zhu; Peixiang Ni; Hua Han; Wei Dong; Xiaoyu Ren; Xiaoli Feng; Peng Cui; Xianran Li; Hao Wang; Xin Xu; Wenxue Zhai; Zhao Xu; Jinsong Zhang; Sijie He; Jianguo Zhang; Jichen Xu; Kunlin Zhang; Xianwu Zheng; Jianhai Dong; Wanyong Zeng; Lin Tao; Xuewei Chen; Jun He; Daofeng Liu; Wei Tian; Chaoguang Tian; Hongai Xia; Gang Li; Hui Gao; Ping Li; Wei Chen; Xudong Wang; Yong Zhang; Jianfei Hu; Jing Wang; Song Liu; Jian Yang; Guangyu Zhang; Yuqing Xiong; Zhijie Li; Long Mao; Chengshu Zhou; Zhen Zhu; Runsheng Chen; Bailin Hao; Weimou Zheng; Shouyi Chen; Wei Guo; Guojie Li; Siqi Liu; Guyang Huang; Ming Tao; Jian Wang; Lihuang Zhu; Longping Yuan; Huanming Yang

2001-01-01

170

Rheological properties of rice-blackgram batter while replacing white rice with brown rice.  

PubMed

Rice-blackgram batter is a raw material for many traditional convenience foods in Asia. Reformulation of traditional convenience food by replacing white rice with whole rice (brown rice) is a novel method to reduce the consumption of refined grain and increase the intake of whole grain in our diet. In this study, rheological properties of rice-blackgram batter was investigated while replacing white rice with brown rice at five levels (T1--0% replacement (control), T2--25% replacement, T3--50% replacement, T4--75% replacement, and T5--100% replacement). The shear stress versus shear rate plot indicates that the rice-blackgram batter exhibited non-Newtonian fluid behavior (shear thinning property) even after 100% replacement of white rice with brown rice. The rheological characteristics of rice-blackgram batters fitted reasonably well in Cassan (r2 = 0.8521-0.9856) and power law (r2 = 0.8042-0.9823) models. Brown rice replacement at all levels did not affect the flow behavior index, yield stress, consistency coefficient, and apparent viscosity of batter at 25 degrees C. However, at higher temperature, the viscosity was greater for T4 and T5 (no difference between them) than T1, T2, and T3 (no difference between them) batters. Further research is required to determine the sensory attributes and acceptability of the cooked products with brown rice-blended batter. PMID:23751544

Manickavasagan, Annamalai; Al-Marhubi, Insaaf Mohd; Dev, Satyanarayan

2014-06-01

171

Ecosystem element cycling Introduction  

E-print Network

Ecosystem element cycling Introduction An ecosystem consists of all the biological organisms and the physical environments they occupy together within a defined area [1]. The actual boundaries of an ecosystem are generally defined by researchers studying the ecosystem, who are usually interested in understanding

Ickert-Bond, Steffi

172

Internet Geography: Ecosystems  

NSDL National Science Digital Library

This site about ecosystems and biomes contains a map of different ecosystems, and provides rainfall statistics for each biome. There are sections on tropical rainforest, taiga (or boreal forest), savanna, desert, and tundra ecosystems. Each section describes the biome and its origins, where it is found, and how humans impact it. In some cases, sustainable development of the ecosystem is explained.

173

Mammoth ecosystem: Climatic areal, animal's density and cause of extinctions  

Microsoft Academic Search

During the last glaciations Mammoth Ecosystem (ME) occupied territory from present-day France to Canada and from the Arctic islands to China. This ecosystem played major role in global carbon cycle and human settling around the planet. Causes of extinction of this ecosystem are debatable. Analyses of hundreds of radiocarbon dates of ME animal fossil remains showed that warming and moistening

S. Zimov; N. Zimov; G. Zimova; S. F. Chapin

2008-01-01

174

Cooking with Rice (not instant)  

E-print Network

(6 servings). To make rice, mix the following ingredients in a medium saucepan: 1 cup uncooked rice 1 tablespoon margarine (if you like) 2 cups water ? teaspoon salt (if you like) Bring the contents to a boil and stir once or twice. Reduce... or washed before cooking. Rice Salad (makes 6 servings) What you need 3 cups cooked rice, cooled 2 hard-cooked eggs, chopped ? cup mayonnaise-type salad dressing ? cup finely chopped green onions...

Anding, Jenna

2008-12-09

175

Red Rice Research and Control.  

E-print Network

Physiology, Louisiana State University, Baton Rouge. Baldwin, Ford L., University of Arkansas Cooperative Extension Service, Little Rock. Bourgeois, W. J., Department of Plant Pathology and Crop Physiology, Louisiana State University, Baton Rouge. Cox... ...................................... 10 E. A. Sonnier RED RICE CONTROL IN ALTERNATE CROPS ................................ 16 F. L. Baldwin ..# RED RICE CONTROL ..................................................lg B. A. Huey and F. L. Baldwin RED RICE HERBICIDE SCREENING TESTS...

Baker, John B.; Baldwin, Ford L.; Bourgeois, W.J.; Cox, Clodis H.; Craigmiles, Julian P.; Dishman, William D.; Eastin, E. Ford; Helpert, Charles W.; Hill, Lewis C.; Huey, Bobby A.; Klosterboer, Arlen D.; Sonnier, Earl A.

1980-01-01

176

Climate Feedback on Methane Emissions From Terrestrial Ecosystems  

NASA Astrophysics Data System (ADS)

Terrestrial ecosystems are one of the important components of the climate system that are bound to change and cause feedbacks with global warming. One major mechanism of this feedback is the response of biological processes, mostly bacteria, that produce or consume greenhouse gases such as carbon dioxide (CO2) and methane (CH4). Here we are concerned with the emissions of CH4 which is considered the most important non-CO2 greenhouse gas because it has more than doubled during the last century and is about 20 times more potent per kilogram once emitted to the atmosphere. Methane is produced by anaerobic methanogens in wetland soils and rice paddies, and is consumed by methanotrophic bacteria in aerobic and upland soils. Together these sources account for about 40-60% of global methane emissions. Properly accounting for the feedback of CH4 emissions with temperature in Earth Systems Models (ESMs) remains an open challenge in part due to the lack of experimental data. Reported Q10 values (factor by which reaction rate increases for a 10°C rise in temperature) of CH4 flux from wetlands and rice agriculture vary over an order of magnitude for reasons that are not well known contributing to this uncertainty. We report here a suite of experimental measurements to determine the Q10 of CH4 flux from rice agriculture and to understand how it depends on the temperature responses of its underlying processes. Since processes may have different Q10 values it is essential that these are properly represented in ESMs. We grew rice plants in temperature-controlled mesocosms at 20, 24, 28 and 32°C over two seasons (years 2009 - 2010) and measured flux, production and oxidation rates, at regular intervals using static chambers, soil core incubations, and carbon isotopes (?13C-CH4), respectively. In addition we used qPCR techniques to measure methyl coenzyme M reductase (mcrA) and particulate methane monooxygenase (pmoA) genes from mesocosm soil cores to establish the temperature response of methanogen and methanotroph populations. We used a simple box model to relate the flux Q10 with the Q10 values for production, oxidation, and plant-mediated transport. Among other results, we found that flux Q10 values varied between 1 and 20 on a day-to-day basis throughout the growing season, with the largest values occurring at the beginning of the season when fluxes were low. This variation could in part be explained by differences in rates of plant-mediated transport brought about by the different plant growth rates at different temperatures. The seasonally-averaged flux Q10 was ~2, which was lower than the average production Q10 of ~3, indicating that the temperature response of CH4 oxidation in part offsets the increased emissions expected from enhanced production at higher temperatures. This has important implications for how CH4 emissions from terrestrial ecosystems will respond to global warming.

Butenhoff, C. L.; Sithole, A.; Khalil, A. K.; Rice, A. L.; Shearer, M. J.

2012-12-01

177

The State of Ecosystems  

NSDL National Science Digital Library

The recent Millennium Ecosystem Assessment has illustrated that human actions have significantly transformed many of Earths ecosystems. The main findings describe how: humans changed ecosystems dramatically over the past 50 years, changes to ecosystem services may get worse in the next 50 years, global action at all levels can reverse the degradation, and how ecosystem degradation increases risks of sudden changes and reduces benefits for future generations.

ChristiÃÂán Samper (National Museum of Natural History of the Smithsonian Institution;)

2005-08-01

178

Biorefining of high acid rice bran oil  

Microsoft Academic Search

Rice bran oil with a high free fatty acid content (FFA) after degumming and dewaxing can be converted into edible quality\\u000a oil of satisfactory refining characteristics by first adopting the biorefining process to reduce the major portion of the\\u000a FFA by converting them into neutral glycerides with the aid of 1,3-specific lipase under optimum conditions and later deacidifying\\u000a the residual

S. Bhattacharyya; D. K. Bhattacharyya

1989-01-01

179

Leadership Rice The mission of Leadership Rice is to help Rice University undergraduates  

E-print Network

194 Leadership Rice The mission of Leadership Rice is to help Rice University undergraduates from all disciplines build their leadership capacities to create and manage change effectively. Leadership to facilitate change. The introductory course, LEAD 309 Leadership: Theory to Practice (formerly UNIV 309

Richards-Kortum, Rebecca

180

Development of a microarray for two rice subspecies: characterization and validation of gene expression in rice tissues  

PubMed Central

Background Rice is one of the major crop species in the world helping to sustain approximately half of the global population’s diet especially in Asia. However, due to the impact of extreme climate change and global warming, rice crop production and yields may be adversely affected resulting in a world food crisis. Researchers have been keen to understand the effects of drought, temperature and other environmental stress factors on rice plant growth and development. Gene expression microarray technology represents a key strategy for the identification of genes and their associated expression patterns in response to stress. Here, we report on the development of the rice OneArray® microarray platform which is suitable for two major rice subspecies, japonica and indica. Results The rice OneArray® 60-mer, oligonucleotide microarray consists of a total of 21,179 probes covering 20,806 genes of japonica and 13,683 genes of indica. Through a validation study, total RNA isolated from rice shoots and roots were used for comparison of gene expression profiles via microarray examination. The results were submitted to NCBI’s Gene Expression Omnibus (GEO). Data can be found under the GEO accession number GSE50844 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE50844). A list of significantly differentially expressed genes was generated; 438 shoot-specific genes were identified among 3,138 up-regulated genes, and 463 root-specific genes were found among 3,845 down-regulated genes. GO enrichment analysis demonstrates these results are in agreement with the known physiological processes of the different organs/tissues. Furthermore, qRT-PCR validation was performed on 66 genes, and found to significantly correlate with the microarray results (R?=?0.95, p?rice OneArray® 22 K microarray, the first rice microarray, covering both japonica and indica subspecies was designed and validated in a comprehensive study of gene expression in rice tissues. The rice OneArray® microarray platform revealed high specificity and sensitivity. Additional information for the rice OneArray® microarray can be found at http://www.phalanx.com.tw/index.php. PMID:24398116

2014-01-01

181

Large scale germplasm screening for identification of novel rice blast resistance sources  

PubMed Central

Rice is a major cereal crop that contributes significantly to global food security. Biotic stresses, including the rice blast fungus, cause severe yield losses that significantly impair rice production worldwide. The rapid genetic evolution of the fungus often overcomes the resistance conferred by major genes after a few years of intensive agricultural use. Therefore, resistance breeding requires continuous efforts of enriching the reservoir of resistance genes/alleles to effectively tackle the disease. Seed banks represent a rich stock of genetic diversity, however, they are still under-explored for identifying novel genes and/or their functional alleles. We conducted a large-scale screen for new rice blast resistance sources in 4246 geographically diverse rice accessions originating from 13 major rice-growing countries. The accessions were selected from a total collection of over 120,000 accessions based on their annotated rice blast resistance information in the International Rice Genebank. A two-step resistance screening protocol was used involving natural infection in a rice uniform blast nursery and subsequent artificial infections with five single rice blast isolates. The nursery-resistant accessions showed varied disease responses when infected with single isolates, suggesting the presence of diverse resistance genes/alleles in this accession collection. In addition, 289 accessions showed broad-spectrum resistance against all five single rice blast isolates. The selected resistant accessions were genotyped for the presence of the Pi2 resistance gene, thereby identifying potential accessions for isolation of allelic variants of this blast resistance gene. Together, the accession collection with broad spectrum and isolate specific blast resistance represent the core material for isolation of previously unknown blast resistance genes and/or their allelic variants that can be deployed in rice breeding programs.

Vasudevan, Kumar; Vera Cruz, Casiana M.; Gruissem, Wilhelm; Bhullar, Navreet K.

2014-01-01

182

[Submergence tolerance and Sub1 locus in rice].  

PubMed

Great progresses have been made in understanding of both submergence tolerance in rice (Oryza sativa L.) and the molecular mechanism of tolerance over 4 years. Tolerance of rice plants to submergence is controlled by Submergence-1 (Sub1) locus. Sub1 regulates ethylene- and GA-mediated responsiveness, leading to restriction in carbohydrate consumption and quiescence in shoot elongation during submergence and subsequently causing submergence tolerance. This article reviewed two strategies adopted by rice plants to cope with flooding stress, major physiological factors affecting submergence tolerance, and physical mapping of Sub1 locus, as well as the mechanisms of submergence tolerance, and assessed the prospects of the use of Sub1 in hybrid rice production. PMID:20870609

Xiong, Huai-Yang; Li, Yang-Sheng

2010-09-01

183

Rice Insect Management.  

E-print Network

more severe during cold, wet springs. Grasshoppers Several grasshopper species attack rice. The most common and abundant is a meadow grasshopper, ConocephalllS fasciatus (DeGeer). This green insect, 7/ 8- to I 1/ 8-inches long, feeds on leaves... more severe during cold, wet springs. Grasshoppers Several grasshopper species attack rice. The most common and abundant is a meadow grasshopper, ConocephalllS fasciatus (DeGeer). This green insect, 7/ 8- to I 1/ 8-inches long, feeds on leaves...

Drees, Bastiaan M.

1983-01-01

184

Southern rice black-streaked dwarf virus: a white-backed planthopper-transmitted fijivirus threatening rice production in Asia  

PubMed Central

Southern rice black-streaked dwarf virus (SRBSDV), a non-enveloped icosahedral virus with a genome of 10 double-stranded RNA segments, is a novel species in the genus Fijivirus (family Reoviridae) first recognized in 2008. Rice plants infected with this virus exhibit symptoms similar to those caused by Rice black-streaked dwarf virus. Since 2009, the virus has rapidly spread and caused serious rice losses in East and Southeast Asia. Significant progress has been made in recent years in understanding this disease, especially about the functions of the viral genes, rice–virus–insect interactions, and epidemiology and control measures. The virus can be efficiently transmitted by the white-backed planthopper (WBPH, Sogatella furcifera) in a persistent circulative propagative manner but cannot be transmitted by the brown planthopper (Nilaparvata lugens) and small brown planthopper (Laodelphax striatellus). Rice, maize, Chinese sorghum (Coix lacryma-jobi) and other grass weeds can be infected via WBPH. However, only rice plays a major role in the virus infection cycle because of the vector’s preference. In Southeast Asia, WBPH is a long-distance migratory rice pest. The disease cycle can be described as follows: SRBSDV and its WBPH vector overwinter in warm tropical or sub-tropical areas; viruliferous WBPH adults carry the virus from south to north via long-distance migration in early spring, transmit the virus to rice seedlings in the newly colonized areas, and lay eggs on the infected seedlings; the next generation of WBPHs propagate on infected seedlings, become viruliferous, disperse, and cause new disease outbreaks. Several molecular and serological methods have been developed to detect SRBSDV in plant tissues and individual insects. Control measures based on protection from WBPH, including seedbed coverage, chemical seed treatments, and chemical spraying of seedlings, have proven effective in China. PMID:24058362

Zhou, Guohui; Xu, Donglin; Xu, Dagao; Zhang, Maoxin

2013-01-01

185

Molecular evolution of shattering loci in U.S. weedy rice  

PubMed Central

Cultivated rice fields worldwide are plagued with weedy rice, a conspecific weed of cultivated rice (Oryza sativa L.). The persistence of weedy rice has been attributed, in part, to its ability to shatter (disperse) seed prior to crop harvesting. In the United States, separately evolved weedy rice groups have been shown to share genomic identity with exotic domesticated cultivars. Here, we investigate the shattering phenotype in a collection of U.S. weedy rice accessions, as well as wild and cultivated relatives. We find that all U.S. weedy rice groups shatter seeds easily, despite multiple origins, and in contrast to a decrease in shattering ability seen in cultivated groups. We assessed allelic identity and diversity at the major shattering locus, sh4, in weedy rice; we find that all cultivated and weedy rice, regardless of population, share similar haplotypes at sh4, and all contain a single derived mutation associated with decreased seed shattering. Our data constitute the strongest evidence to date of an evolution of weeds from domesticated backgrounds. The combination of a shared cultivar sh4 allele and a highly shattering phenotype, suggests that U.S. weedy rice have re-acquired the shattering trait after divergence from their progenitors through alternative genetic mechanisms. PMID:20584132

Thurber, Carrie S.; Reagon, Michael; Gross, Briana L.; Olsen, Kenneth M.; Jia, Yulin; Caicedo, Ana L.

2010-01-01

186

[Effects of phosphorus-containing substances on arsenic uptake by rice].  

PubMed

The disodium hydrogen phosphate (DSP) and hydroxyapatite (HAP) were added into arsenic contaminated soil, then rice pot experiment was conducted to study the effects of phosphorus (P)-containing substances on arsenic (As) uptake by rice. The results showed that: DSP and HAP significantly increased soil pH and the contents of available P in soil (P < 0.05), activating soil arsenic. And DSP was stronger than HAP in improving the migration ability of As in soil. DSP and HAP treatments both significantly reduced the contents of total As in root, as well as total As and inorganic As in brown rice. But HAP significantly increased total As contents in stem. DSP and HAP treatments had better reducing effects on inorganic As than on total As in brown rice. And DSP had the same reducing effects as HAP on total As and inorganic As in brown rice. Analysis results showed that the contents of As in rice were affected by the antagonism between P and As and the increase of As bio-availability in soil. The antagonism played the major role in this study and it was clearly exhibited in both root and rice. Lower dosage (< or = 0.12 g x kg(-1)) of DSP and HAP increased total biomass of rice and brown rice yield, but with the increase of P addition, the two kinds of P-containing substances obviously inhibited the growth of rice, and inhibition by HAP was relatively light. PMID:25338392

Lei, Ming; Zeng, Min; Liao, Bo-Han; Hu, Li-Qiong; Zhou, Hang; Long, Shui-Bo

2014-08-01

187

Baltimore Ecosystem Study  

NSDL National Science Digital Library

Many ecologists work to understand how various parts of a given ecological system work or function with other systems in their vicinity, but relatively few attempt to bring together all of this work with major urban areas. One such impressive project is the Baltimore Ecosystem Study, which aims to understand metropolitan Baltimore as an ecological system; and in doing so, bring together researchers from the biological, physical and social sciences to work on this formidable task that is truly interdisciplinary. At the site, visitors can learn about the staff of the project and read about its various thematic areas of inquiry, including biodiversity, education, soil, stream and watershed studies, and vegetation. A good place to start before diving into the numerous research projects would be the research area, which explains the basic goals of the project, the theories that the research team is drawing on, and the central questions of its work. The Baltimore Ecosystem Study has also been approved for use in classrooms by the American Association for the Advancement of Science, and educators will find materials that they can draw on to teach various concepts and ideas here as well.

188

Profits and Losses from On-farm Drying and Storage of Rice in Texas.  

E-print Network

less than, EFFECT OF ON-FARM DRYING A STORAGE ON QUALITY i A major consideration in using on-farm dry ing and storage for rice is the effect this methocl has on quality. Although the cost for on-farm drying and storage may be very low, the rice... grower will suffer a loss in income unless quality can be maintained. The price of rough rice is affected by variety, milling yield and grade. On-farm drying. and I storage affect the value of rice only in terms of its effect on milling yield...

Sorenson, J.W. Jr.; Hildreth, R.J.

1957-01-01

189

75 FR 65501 - Minnesota; Major Disaster and Related Determinations  

Federal Register 2010, 2011, 2012, 2013

...this major disaster: Blue Earth, Cottonwood, Dodge, Faribault, Freeborn, Goodhue, Jackson, Lincoln, Lyon, Martin, Mower, Murray, Olmsted, Pipestone, Rice, Rock, Steele, Wabasha, Waseca, Watonwan, and Winona Counties for Public...

2010-10-25

190

Stable isotope analysis of aquatic invertebrate communities in irrigated rice fields cultivated under different management regimes  

Microsoft Academic Search

In this study we have used stable isotope analysis to identify major food resources driving food webs in commercial rice agroecosystems and to examine the effects of agricultural management practices on the trophic structure of these food webs. Potential carbon sources and aquatic macroinvertebrate consumers were collected from large-scale rice farms in south-eastern Australia cultivated under three different crop management

A. L. Wilson; D. S. Ryder; R. J. Watts; M. M. Stevens

2005-01-01

191

Genetic diversity and classification of Oryza sativa with emphasis on Chinese rice germplasm.  

PubMed

Despite extensive studies on cultivated rice, the genetic structure and subdivision of this crop remain unclear at both global and local scales. Using 84 nuclear simple sequence repeat markers, we genotyped a panel of 153 global rice cultivars covering all previously recognized groups and 826 cultivars representing the diversity of Chinese rice germplasm. On the basis of model-based grouping, neighbour-joining tree and principal coordinate analysis, we confirmed the widely accepted five major groups of rice cultivars (indica, aus, aromatic, temperate japonica and tropical japonica), and demonstrated that rayada rice was unique in genealogy and should be treated as a new (the sixth) major group of rice germplasm. With reference to the global classification of rice cultivars, we identified three major groups (indica, temperate japonica and tropical japonica) in Chinese rice germplasm and showed that Chinese temperate japonica contained higher diversity than that of global samples, whereas Chinese indica and tropical japonica maintained slightly lower diversity than that present in the global samples. Particularly, we observed that all seasonal, drought-tolerant and endosperm types occurred within each of three major groups of Chinese cultivars, which does not support previous claims that seasonal differentiation exists in Indica and drought-tolerant differentiation is present in Japonica. It is most likely that differentiation of cultivar types arose multiple times stemming from artificial selection for adaptation to local environments. PMID:24326293

Wang, C-H; Zheng, X-M; Xu, Q; Yuan, X-P; Huang, L; Zhou, H-F; Wei, X-H; Ge, S

2014-05-01

192

Suppression of rice methane emission by sulfate deposition in simulated acid rain  

Microsoft Academic Search

Sulfate in acid rain is known to suppress methane (CH4) emissions from natural freshwater wetlands. Here we examine the possibility that CH4 emissions from rice agriculture may be similarly affected by acid rain, a major and increasing pollution problem in Asia. Our findings suggest that acid rain rates of SO4 2- deposition may help to reduce CH4 emissions from rice

Vincent Gauci; Nancy B. Dise; Graham Howell; Meaghan E. Jenkins

2008-01-01

193

Suppression of rice methane emission by sulfate deposition in simulated acid rain  

Microsoft Academic Search

Sulfate in acid rain is known to suppress methane (CH4) emissions from natural freshwater wetlands. Here we examine the possibility that CH4 emissions from rice agriculture may be similarly affected by acid rain, a major and increasing pollution problem in Asia. Our findings suggest that acid rain rates of SO42? deposition may help to reduce CH4 emissions from rice agriculture.

Vincent Gauci; Nancy B. Dise; Graham Howell; Meaghan E. Jenkins

2008-01-01

194

Field water management to save water and increase its productivity in irrigated lowland rice  

Microsoft Academic Search

Rice production in Asia needs to increase to feed a growing population whereas water for irrigation is getting scarcer. Major challenges are to (i) save water; (ii) increase water productivity and (iii) produce more rice with less water. This study analyzes the ways in which water-saving irrigation can help to meet these challenges at the field level. The analyses are

B. A. M. Bouman; T. P. Tuong

2001-01-01

195

Opportunities to increasing dry season rice productivity in low temperature affected areas  

E-print Network

Opportunities to increasing dry season rice productivity in low temperature affected areas Sipaseuth a , J. Basnayake b,*, S. Fukai b , T.C. Farrell b , M. Senthonghae a , Sengkeo a , S. Phamixay March 2007 Abstract Rice is a major source of food for more than 2.7 billion people and planted

van Kessel, Chris

196

Insect-Resistant GM Rice in Farmers' Fields: Assessing Productivity and Health Effects in China  

Microsoft Academic Search

Although no country to date has released a major genetically modified (GM) food grain crop, China is on the threshold of commercializing GM rice. This paper studies two of the four GM varieties that are now in farm-level preproduction trials, the last step before commercialization. Farm surveys of randomly selected farm households that are cultivating the insect-resistant GM rice varieties,

Jikun Huang; Ruifa Hu; Scott Rozelle; Carl Pray

2005-01-01

197

Novel insights into rice innate immunity against bacterial and fungal pathogens.  

PubMed

Rice feeds more than half of the world's population. Rice blast, caused by the fungal pathogen Magnaporthe oryzae, and bacterial blight, caused by the bacterial pathogen Xanthomonas oryzae pv. oryzae, are major constraints to rice production worldwide. Genome sequencing and extensive molecular analysis has led to the identification of many new pathogen-associated molecular patterns (PAMPs) and avirulence and virulence effectors in both pathogens, as well as effector targets and receptors in the rice host. Characterization of these effectors, host targets, and resistance genes has provided new insight into innate immunity in plants. Some of the new findings, such as the binding activity of X. oryzae transcriptional activator-like (TAL) effectors to specific rice genomic sequences, are being used for the development of effective disease control methods and genome modification tools. This review summarizes the recent progress toward understanding the recognition and signaling events that govern rice innate immunity. PMID:24906128

Liu, Wende; Liu, Jinling; Triplett, Lindsay; Leach, Jan E; Wang, Guo-Liang

2014-01-01

198

Arsenic, Organic Foods, and Brown Rice Syrup  

PubMed Central

Background: Rice can be a major source of inorganic arsenic (Asi) for many sub-populations. Rice products are also used as ingredients in prepared foods, some of which may not be obviously rice based. Organic brown rice syrup (OBRS) is used as a sweetener in organic food products as an alternative to high-fructose corn syrup. We hypothesized that OBRS introduces As into these products. Objective: We determined the concentration and speciation of As in commercially available brown rice syrups and in products containing OBRS, including toddler formula, cereal/energy bars, and high-energy foods used by endurance athletes. Methods: We used inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography coupled to ICP-MS to determine total As (Astotal) concentrations and As speciation in products purchased via the Internet or in stores in the Hanover, New Hampshire, area. Discussion: We found that OBRS can contain high concentrations of Asi and dimethyl-arsenate (DMA). An “organic” toddler milk formula containing OBRS as the primary ingredient had Astotal concentrations up to six times the U.S. Environmental Protection Agency safe drinking water limit. Cereal bars and high-energy foods containing OBRS also had higher As concentrations than equivalent products that did not contain OBRS. Asi was the main As species in most food products tested in this study. Conclusions: There are currently no U.S. regulations applicable to As in food, but our findings suggest that the OBRS products we evaluated may introduce significant concentrations of Asi into an individual’s diet. Thus, we conclude that there is an urgent need for regulatory limits on As in food. PMID:22336149

Taylor, Vivien F.; Karagas, Margaret R.; Punshon, Tracy; Cottingham, Kathryn L.

2012-01-01

199

Narendra Anand Rice University  

E-print Network

Researcher, Networking and Communications Lab Prototyped hybrid Software Defined Radio platform. Began of components, and creating an option comprised of 802.11b Radio, low-power FPGA, and ARM 9 microcontroller mobile devices. AwardsAcademic Honors · Rice University Hershel M. Rich Invention Award Spring 2012

200

RICE UNIVERSITY COUNSELING RECORD  

E-print Network

Employee Assistance Referral Suspension With Pay; Reassignment of Job Duties Termination of Employment Written Reprimand Employee Assistance Referral Suspension With Pay; Reassignment of Job Duties TerminationRICE UNIVERSITY COUNSELING RECORD Employee Name Date Issued Employee ID # Job Title Work Location

201

visitor parking rice village  

E-print Network

, CONTROLLER'S OFFICE, ADMINISTRATIVE SYSTEMS) university boulevard greenbriar chaucer rice boulevard campanile road whitley shepherd wilton hazard kent ashby cherokee alumnidrive sunset boulevard remington main, Engineering and Planning Lot G Greenbriar Lot GA Greenbriar Annex H Hess Court Lot K Keck Lot L Lovett Lot N

Alvarez, Pedro J.

202

Landscape ecosystems of the University of Michigan Biological Station: Ecosystem diversity and ground-cover diversity  

SciTech Connect

The aim of this research is to provide an understanding of the three-dimensional (air-earth-organism) units of the landscape of the University of Michigan Biological Station (UMBS) that the author calls landscape ecosystem types, or simply ecosystems. Specifically, he has focused on the kinds, spatial location and patterns, and composition (physiography, soil, vegetation) of the local landscape ecosystem types of UMBS and Colonial Point. Future research on the functioning of these ecosystems together with inventories of their plant and animal life will add significantly to the landscape ecology research that has been initiated. A major reason for this research is to provide the conceptual basis and baseline data for understanding ecosystem change. Although it is popular to speak of climate change, entire ecosystems change; some components change faster than others.

Pearsall, D.R.

1995-12-31

203

A rice phenomics study—phenotype scoring and seed propagation of a T-DNA insertion-induced rice mutant population  

Microsoft Academic Search

With the completion of the rice genome sequencing project, the next major challenge is the large-scale determination of gene\\u000a function. As an important crop and a model organism, rice provides major insights into gene functions important for crop growth\\u000a or production. Phenomics with detailed information about tagged populations provides a good tool for functional genomics analysis.\\u000a By a T-DNA insertional

Chyr-Guan Chern; Ming-Jen Fan; Su-May Yu; Po-Chang Lu; Yao-Cheng Lin; Fu-Jin Wei; Sheng-Chung Huang; Shu Chen; Ming-Hsing Lai; Ching-Shan Tseng; Hsing-Mu Yen; Woei-Shyuan Jwo; Chen-Chia Wu; Tung-Lung Yang; Lung-Sheng Li; Yih-Cheng Kuo; Su-Mien Li; Charng-Pei Li; Chiu-Kai Wey; Arunee Trisiriroj; Hsing-Fang Lee; Yue-Ie C. Hsing

2007-01-01

204

MOBILE PROXIMITY PAYMENT: ECOSYSTEM  

E-print Network

MOBILE PROXIMITY PAYMENT: ECOSYSTEM AND OVERVIEW OF NFC TECHNOLOGY 1. Introduction Handsets confirm and heterogeneous. The Mobile Payment ecosystem involves a number of partners, such as: · banks; · Mobile Network

Shamos, Michael I.

205

Evaluation of potential effects of soil available phosphorus on soil arsenic availability and paddy rice inorganic arsenic content.  

PubMed

The transfer of arsenic from paddy field to rice is a major exposure route of the highly toxic element to humans. The aim of our study is to explore the effects of soil available phosphorus on As uptake by rice, and identify the effects of soil properties on arsenic transfer from soil to rice under actual field conditions. 56 pairs of topsoil and rice samples were collected. The relevant parameters in soil and the inorganic arsenic in rice grains were analyzed, and then all the results were treated by statistical methods. Results show that the main factors influencing the uptake by rice grain include soil pH and available phosphorus. The eventual impact of phosphorus is identified as the suppression of As uptake by rice grains. The competition for transporters from soil to roots between arsenic and phosphorus in rhizosphere soil has been a dominant feature. PMID:24598788

Jiang, Wei; Hou, Qingye; Yang, Zhongfang; Zhong, Cong; Zheng, Guodong; Yang, Zhiqiang; Li, Jie

2014-05-01

206

Consideration of Ecosystem for ICME  

SciTech Connect

As the Integrated Computational Materials Engineering (ICME) emerges as a hot topic, computation, experimentation, and digital database are identified as its three major components. Efforts are being actively made from various aspects to bring ICME to reality. However, many factors that would affect ICEM development still remain vague. This paper is an attempt to discuss the needs for establishing a database centered ecosystem to facilitate ICEM development.

Ren, Weiju [ORNL

2013-01-01

207

Biogeochemical Processes in Microbial Ecosystems  

NASA Technical Reports Server (NTRS)

The hierarchical organization of microbial ecosystems determines process rates that shape Earth's environment, create the biomarker sedimentary and atmospheric signatures of life, and define the stage upon which major evolutionary events occurred. In order to understand how microorganisms have shaped the global environment of Earth and, potentially, other worlds, we must develop an experimental paradigm that links biogeochemical processes with ever-changing temporal and spatial distributions of microbial populations and their metabolic properties. Additional information is contained in the original extended abstract.

DesMarais, David J.

2001-01-01

208

Ecosystem Health: Energy Indicators.  

EPA Science Inventory

Just as for human beings health is a concept that applies to the condition of the whole organism, the health of an ecosystem refers to the condition of the ecosystem as a whole. For this reason, the study and characterization of ecosystems is fundamental to establishing accurate ...

209

The polluted ecosystem game  

Microsoft Academic Search

Purpose – The purpose of this paper is to address the issue of optimal management of ecosystems by developing a dynamic model of strategic behavior by users\\/communities of an ecosystem such as a lake, which is subject to pollution resulting from the users. More specifically, it builds a model of two ecosystems that are spatially connected. Design\\/methodology\\/approach – The paper

W. A. Brock; W. D. Dechert

2008-01-01

210

I Spy an Ecosystem  

NSDL National Science Digital Library

We hear the word ecosystems in the news and at school but just what are ecosystems? It turns out there are lots of ecosystems. You might even learn you have some inside you! Also in: Français | Español

Biology

2009-09-22

211

The Ecosystem Science Center  

E-print Network

The Ecosystem Science Center 2010-2011 Annual report Photo, by graduate student Alex of the Ecosystem Science Center for the period July 1, 2010 July 1, 2011 Introduction to ESC ­ A Message from .......................................... 40 1 #12;A Message from the ESC Director The Ecosystem Science Center has now completed its

212

The Ecosystem Science Center  

E-print Network

1 The Ecosystem Science Center 2011-2012 Annual report #12;2 Table of Contents This document summarizes the activities of the Ecosystem Science Center for the period from July 1, 2011 July 1, 2012 of the Ecosystem Science Center who supported this research project in Calumet watershed with a graduate research

213

Emergy and ecosystem complexity  

Microsoft Academic Search

The question “What drives complexity?” is addressed in this paper. To answer this question, we explore the way energy and material resources of different quality flow through ecosystems and support, directly and indirectly, ecosystems growth and development. Processes of resource transformation throughout the ecosystem build order, cycle materials, generate and sustain information. Energy drives all these processes and energetic principles

Sergio Ulgiati; Mark T. Brown

2009-01-01

214

Localization and speciation of mercury in brown rice with implications for pan-Asian public health.  

PubMed

Cultivation of paddy rice for human consumption is a dominant agricultural activity throughout Asia. High levels of mercury (Hg) in rice grain pose a potential threat to human health, although the extent of risk is dependent on the chemical speciation of Hg inside the grain. We have investigated the speciation and localization of Hg in three fractions of rice grain (hull, bran, and white rice) collected from a Hg-contaminated region in China. On a mass basis, the majority of inorganic mercury (IHg) in a rice grain is found in hull and bran. However, the majority of the more toxic species methyl mercury (MeHg) is found in edible white rice. Our data show that during grain processing, most of the IHg (?78%) is eliminated, but the majority of the MeHg remains in the food product (?80%). Synchrotron radiation microscopic X-ray fluorescence (SR-?XRF) mapping shows strong localization of Hg at the surface of brown rice grains, corresponding to the pericarp and aleurone layer. We infer that this Hg is predominantly IHg absorbed from the atmosphere. Based on X-ray absorption near-edge spectroscopy (XANES) data we propose that IHg in bran is primarily bound to cysteine, and is associated with phytochelatins. Consequently, IHg is largely immobile and restricted to the outer layers of rice grain. MeHg in bran is primarily bound to cysteine and is associated with proteins. However, this MeHg-cysteine association behaves like a mobile nutrient and is actively transported to the endosperm during seed ripening. Concentration of MeHg-cysteine in white rice has implications for public health. There is growing evidence for Hg contamination of rice throughout Asia due to point and diffuse sources of Hg pollution. The magnitude of the associated risk must be quantified through better understanding of the localization and speciation of mercury in rice. Our work makes an effort to contribute to this understanding. PMID:24925231

Meng, Bo; Feng, Xinbin; Qiu, Guangle; Anderson, Christopher W N; Wang, Jianxu; Zhao, Lei

2014-07-15

215

Texas Rice, Volume IV, Number 2  

E-print Network

interest in high quality long grain rice from the United States. Their visit will be sponsored by the Foreign Agricultural Service of the U.S. Department of Agriculture with cooperation from the US Rice Producers Association, the USA Rice Federation... interest in high quality long grain rice from the United States. Their visit will be sponsored by the Foreign Agricultural Service of the U.S. Department of Agriculture with cooperation from the US Rice Producers Association, the USA Rice Federation...

216

Major depression  

MedlinePLUS

... major; Depression - clinical; Clinical depression; Unipolar depression; Major depressive disorder ... Doctors do not know the exact causes of depression. It is believed ... responsible. This may be due to a problem with your genes. Or ...

217

Genetic Differentiation Revealed by Selective Loci of Drought-Responding EST-SSRs between Upland and Lowland Rice in China  

PubMed Central

Upland and lowland rice (Oryza sativa L.) represent two of the most important rice ecotypes adapted to ago-ecosystems with contrasting soil-water conditions. Upland rice, domesticated in the water-limited environment, contains valuable drought-resistant characters that can be used in water-saving breeding. Knowledge about the divergence between upland and lowland rice will provide valuable cues for the evolution of drought-resistance in rice. Genetic differentiation between upland and lowland rice was explored by 47 Simple Sequence Repeats (SSRs) located in drought responding expressed sequence tags (ESTs) among 377 rice landraces. The morphological traits of drought-resistance were evaluated in the field experiments. Different outlier loci were detected in the japonica and indica subspecies, respectively. Considerable genetic differentiation between upland and lowland rice on these outlier loci was estimated in japonica (Fst?=?0.258) and indica (Fst?=?0.127). Furthermore, populations of the upland and lowland ecotypes were clustered separately on these outlier loci. A significant correlation between genetic distance matrices and the dissimilarity matrices of drought-resistant traits was determined, indicating a certain relationship between the upland-lowland rice differentiation and the drought-resistance. Divergent selections occur between upland and lowland rice on the drought-resistance as the Qsts of some drought-resistant traits are significantly higher than the neutral Fst. In addition, the upland- and lowland-preferable alleles responded differently among ecotypes or allelic types under osmotic stress. This shows the evolutionary signature of drought resistance at the gene expression level. The findings of this study can strengthen our understanding of the evolution of drought-resistance in rice with significant implications in the improvement of rice drought-resistance. PMID:25286109

Xia, Hui; Zheng, Xiaoguo; Chen, Liang; Gao, Huan; Yang, Hua; Long, Ping; Rong, Jun; Lu, Baorong; Li, Jiajia; Luo, Lijun

2014-01-01

218

Conservation and Management of Tropical Coastal Ecosystems  

Microsoft Academic Search

All major coastal ecosystems in the tropics are being degraded. The problems include losses of biodiversity, reduced ecosystem\\u000a functions, and costs to coastal human societies. Declines in species’ abundances, and habitat loss and modification are the\\u000a result of the demands for aquaculture, port construction, trawling, excessive nutrient loads, overfishing and collecting,\\u000a sedimentation from catchment activities, invasive species, and climate change.

William Gladstone

219

Methylmercury Bioaccumulation in Rice and Wetland Biota: employing integrated indices of processes that drive methylmercury risk  

NASA Astrophysics Data System (ADS)

Wetlands often are associated with elevated methylmercury (MeHg) production and food web bioaccumulation, making them potentially important sources of Hg to surrounding waters and to wetland-dependent fish and wildlife. However, the cycling of MeHg through wetlands can vary markedly with wetland type. Agricultural wetlands such as rice fields can exhibit particularly pronounced MeHg concentrations and bioaccumulation because their biogeochemical, hydrological, and ecological characteristics facilitate the conversion of inorganic mercury (Hg) to MeHg. Rice fields are characterized by a series of seasonal extreme wetting and drying cycles, sulfate-containing fertilizers, and high levels of labile organic carbon, all of which are key processes in the Hg cycle. Rice fields comprise approximately 20% of freshwater habitats and 11% of cultivated land area globally, providing critical wildlife habitat while offering substantial economic, human health, and ecosystem benefits. Thus, there is strong impetus to better understand the drivers of Hg cycling in rice fields and to develop useful management approaches for minimizing Hg risk associated with rice agriculture without compromising rice production. We examined the role of rice wetlands on MeHg bioaccumulation through foodwebs by employing biosentinel caged fish as integrators of MeHg cycling processes. With experimental field studies in California's Central Valley, we placed biosentinel fishes into nine rice wetlands that were subjected to three different harvest strategies, and into nine managed wetlands that encompassed three different hydrological regimes. We simultaneously measured a suite of biogeochemical processes in surface water, sediment, and pore water in order to link the response in fish Hg bioaccumulation with within-field processes that regulate MeHg cycling. Our preliminary results indicate that fish Hg concentrations were 1.6 times higher in rice wetlands than in managed wetlands. Additionally, fish Hg concentrations increased across rice fields from inlets to outlets indicating that in situ processes enhanced MeHg production rice fields, whereas concentrations decreased from inlets to outlets in managed wetlands. Finally, our preliminary results suggest organic carbon associated with rice plants was an important contributor to fish Hg concentrations, whereas plants in managed wetlands were not strongly linked to fish Hg concentrations. Our preliminary findings suggest that there are strong linkages between biogeochemical processes inherent in rice wetlands and MeHg cycling and bioaccumulation, which are further described in a companion presentation by Windham-Myers (this session). These results have important implications for managing MeHg risk in areas with extensive rice agriculture.

Eagles-Smith, C.; Ackerman, J.; Windham-Myers, L.; Fleck, J.

2013-12-01

220

Drying Rough Rice in Storage.  

E-print Network

undried riff' with an initial moisture content of 18 to 19 perce a' for 9 days without grade loss from discolored kc I" nels. t l i r Aeration was effective in maintaining the ca ic dition of rice after it was dried to a safe stora! h level. Rice...- ment needs, air flow requirements and operating schedules for drying and storing rice. It includes information on the relationship of drying time to the drying air temperature, moisture content and depth of rice. Information on the effects...

Sorenson, J. W. Jr.; Crane, L. E.

1960-01-01

221

RICE UNIVERSITY CONGRUENCY EFFECTS WITH  

E-print Network

RICE UNIVERSITY CONGRUENCY EFFECTS WITH DYNAMIC AUDITORY STIMULI by BRUCE N. WALKER A THESIS of Psychology ____________________________________ David M. Lane, Associate Professor Department of Psychology

222

Anti-oxidative analysis, and identification and quantification of anthocyanin pigments in different coloured rice.  

PubMed

Anthocyanin pigments in coloured rice cultivars were isolated and identified using high-performance liquid chromatography techniques. Two black rice cultivars (Asamurasaki, Okunomurasaki) contained three major anthocyanins: cyanidin-3-glucoside, peonidin-3-glucoside and malvidin. Chinakuromai (black) rice additionally contained a fourth anthocyanin, petunidin-3-glucoside. Four red rice cultivars contained only malvidin. The total anthocyanin content varied greatly among black rice cultivars (79.5-473.7 mg/100g), but was lower in red rice (7.9-34.4 mg/100g). Total phenolic content was similar between red (460.32-725.69 mg/100g) and black (417.11-687.24 mg/100g) rice. The oxygen radical absorbing capacity was ranked as follows: red (69.91-130.32 ?mol Trolox/g)>black (55.49-64.85 ?mol Trolox/g)>green (35.32 ?mol Trolox/g)>white (21.81 ?mol Trolox/g) rice. The antioxidant capacity resulted mainly from the seed capsule, not the endosperm. The anthocyanin pigments contributed little to the total antioxidant capacity of red (0.03-0.1%) and black (0.5-2.5%) rice cultivars. Hence, the antioxidant capacity is derived mainly from other phenolic compounds. PMID:22980872

Chen, Xiao Qiong; Nagao, Norio; Itani, Tomio; Irifune, Kohei

2012-12-15

223

Rice proteomics: a model system for crop improvement and food security.  

PubMed

Rice proteomics has progressed at a tremendous pace since the year 2000, and that has resulted in establishing and understanding the proteomes of tissues, organs, and organelles under both normal and abnormal (adverse) environmental conditions. Established proteomes have also helped in re-annotating the rice genome and revealing the new role of previously known proteins. The progress of rice proteomics had recognized it as the corner/stepping stone for at least cereal crops. Rice proteomics remains a model system for crops as per its exemplary proteomics research. Proteomics-based discoveries in rice are likely to be translated in improving crop plants and vice versa against ever-changing environmental factors. This review comprehensively covers rice proteomics studies from August 2010 to July 2013, with major focus on rice responses to diverse abiotic (drought, salt, oxidative, temperature, nutrient, hormone, metal ions, UV radiation, and ozone) as well as various biotic stresses, especially rice-pathogen interactions. The differentially regulated proteins in response to various abiotic stresses in different tissues have also been summarized, indicating key metabolic and regulatory pathways. We envision a significant role of rice proteomics in addressing the global ground level problem of food security, to meet the demands of the human population which is expected to reach six to nine billion by 2040. PMID:24323464

Kim, Sun Tae; Kim, Sang Gon; Agrawal, Ganesh Kumar; Kikuchi, Shoshi; Rakwal, Randeep

2014-03-01

224

Study of chemical pretreatment and enzymatic saccharification for producing fermentable sugars from rice straw.  

PubMed

This study evaluated a cost-effective approach for the conversion of rice straw into fermentable sugars. The composition of rice straw pretreated with 1 % sulfuric acid or 1 % sodium hydroxide solution was compared to rice straw with no chemical pretreatment. Enzymatic saccharification experiments on non-pretreated rice straw (NPRS), pretreated rice straw (PRS), and pretreated rice straw with acid hydrolysate (PRSAH) were conducted in a series of batch reactors. The results indicated that pretreating the rice straw with dilute acid and base increased the cellulose content from 38 % to over 50 %. During enzymatic saccharification, straight aliphatic cellulose was hydrolyzed before branched hemicellulose, and glucose was the major hydrolysis product. The glucose yield was 0.52 g glucose/g for NPRS and was comparable to the yields of 0.50 g glucose/g for PRS and 0.58 g glucose/g for PRSAH. The hydrolysis of rice straw to produce glucose can be described by a first-order reaction with a rate constant of 0.0550 d(-1) for NPRS, 0.0653 d(-1) for PRSAH, and 0.0654 d(-1) for PRS. Overall, the production of fermentable sugars from ground rice straw will be more cost effective if the straw is not pretreated with chemicals. PMID:24346765

Chen, Wen-Hsing; Chen, Yi-Chun; Lin, Jih-Gaw

2014-07-01

225

Neglecting Rice Milling Yield and Quality Underestimates Economic Losses from High-Temperature Stress  

PubMed Central

Future increases in global surface temperature threaten those worldwide who depend on rice production for their livelihoods and food security. Past analyses of high-temperature stress on rice production have focused on paddy yield and have failed to account for the detrimental impact of high temperatures on milling quality outcomes, which ultimately determine edible (marketable) rice yield and market value. Using genotype specific rice yield and milling quality data on six common rice varieties from Arkansas, USA, combined with on-site, half-hourly and daily temperature observations, we show a nonlinear effect of high-temperature stress exposure on yield and milling quality. A 1°C increase in average growing season temperature reduces paddy yield by 6.2%, total milled rice yield by 7.1% to 8.0%, head rice yield by 9.0% to 13.8%, and total milling revenue by 8.1% to 11.0%, across genotypes. Our results indicate that failure to account for changes in milling quality leads to understatement of the impacts of high temperatures on rice production outcomes. These dramatic losses result from reduced paddy yield and increased percentages of chalky and broken kernels, which together decrease the quantity and market value of milled rice. Recently published estimates show paddy yield reductions of up to 10% across the major rice-producing regions of South and Southeast Asia due to rising temperatures. The results of our study suggest that the often-cited 10% figure underestimates the economic implications of climate change for rice producers, thus potentially threatening future food security for global rice producers and consumers. PMID:23991056

Lyman, Nathaniel B.; Jagadish, Krishna S. V.; Nalley, L. Lanier; Dixon, Bruce L.; Siebenmorgen, Terry

2013-01-01

226

Neglecting rice milling yield and quality underestimates economic losses from high-temperature stress.  

PubMed

Future increases in global surface temperature threaten those worldwide who depend on rice production for their livelihoods and food security. Past analyses of high-temperature stress on rice production have focused on paddy yield and have failed to account for the detrimental impact of high temperatures on milling quality outcomes, which ultimately determine edible (marketable) rice yield and market value. Using genotype specific rice yield and milling quality data on six common rice varieties from Arkansas, USA, combined with on-site, half-hourly and daily temperature observations, we show a nonlinear effect of high-temperature stress exposure on yield and milling quality. A 1 °C increase in average growing season temperature reduces paddy yield by 6.2%, total milled rice yield by 7.1% to 8.0%, head rice yield by 9.0% to 13.8%, and total milling revenue by 8.1% to 11.0%, across genotypes. Our results indicate that failure to account for changes in milling quality leads to understatement of the impacts of high temperatures on rice production outcomes. These dramatic losses result from reduced paddy yield and increased percentages of chalky and broken kernels, which together decrease the quantity and market value of milled rice. Recently published estimates show paddy yield reductions of up to 10% across the major rice-producing regions of South and Southeast Asia due to rising temperatures. The results of our study suggest that the often-cited 10% figure underestimates the economic implications of climate change for rice producers, thus potentially threatening future food security for global rice producers and consumers. PMID:23991056

Lyman, Nathaniel B; Jagadish, Krishna S V; Nalley, L Lanier; Dixon, Bruce L; Siebenmorgen, Terry

2013-01-01

227

Water management affects arsenic and cadmium accumulation in different rice cultivars.  

PubMed

Paddy rice (Oryza sativa L.) is a staple food and one of the major sources of dietary arsenic (As) and cadmium (Cd) in Asia. A field experiment was conducted to investigate the effects of four water management regimes (aerobic, intermittent irrigation, conventional irrigation and flooding) on As and Cd accumulation in seven major rice cultivars grown in Zhejiang province, east China. With increasing irrigation from aerobic to flooded conditions, the soil HCl-extractable As concentrations increased significantly and the HCl-extractable Cd concentrations decreased significantly. These trends were consistent with the As and Cd concentrations in the straw, husk and brown rice. Water management both before and after the full tillering stage affected As and Cd accumulation in the grains. The intermittent and conventional treatments produced higher grain yields than the aerobic and flooded treatments. Cd concentrations in brown rice varied 13.1-40.8 times and As varied 1.75-8.80 times among the four water management regimes. Cd and As accumulation in brown rice varied among the rice cultivars, with Guodao 6 (GD6) was a low Cd but high-As-accumulating cultivar while Indonesia (IR) and Yongyou 9 (YY9) were low As but high-Cd-accumulating cultivars. Brown rice Cd and As concentrations in the 7 cultivars were significantly negatively correlated. The results indicate that As and Cd accumulated in rice grains with opposite trends that were influenced by both water management and rice cultivar. Production of 'safe' rice with respect to As and Cd might be possible by balancing water management and rice cultivar according to the severity of soil pollution. PMID:23719663

Hu, Pengjie; Huang, Jiexue; Ouyang, Younan; Wu, Longhua; Song, Jing; Wang, Songfeng; Li, Zhu; Han, Cunliang; Zhou, Liqiang; Huang, Yujuan; Luo, Yongming; Christie, Peter

2013-12-01

228

Arsenic levels in rice grain and assessment of daily dietary intake of arsenic from rice in arsenic-contaminated regions of Bangladesh--implications to groundwater irrigation.  

PubMed

Chronic exposure to arsenic (As) causes significant human health effects, including various cancers and skin disorders. Naturally elevated concentrations of As have been detected in the groundwater of Bangladesh. Dietary intake and drinking water are the major routes of As exposure for humans. The objectives of this study were to measure As concentrations in rice grain collected from households in As-affected villages of Bangladesh where groundwater is used for agricultural irrigation and to estimate the daily intake of As consumed by the villagers from rice. The median and mean total As contents in 214 rice grain samples were 131 and 143 microg/kg, respectively, with a range of 2-557 microg/kg (dry weight, dw). Arsenic concentrations in control rice samples imported from Pakistan and India and on sale in Australian supermarkets were significantly lower (p < 0.001) than in rice from contaminated areas. Daily dietary intake of As from rice was 56.4 microg for adults (males and females) while the total daily intake of As from rice and from drinking water was 888.4 and 706.4 microg for adult males and adult females, respectively. From our study, it appears that the villagers are consuming a significant amount of As from rice and drinking water. The results suggest that the communities in the villages studied are potentially at risk of suffering from arsenic-related diseases. PMID:19142738

Rahman, Mohammad Mahmudur; Owens, Gary; Naidu, Ravi

2009-04-01

229

Weed management in dry-seeded rice ( Oryza sativa) cultivated in the furrow-irrigated raised-bed planting system  

Microsoft Academic Search

Dry seeding of rice (Oryza sativa L.) in the furrow-irrigated raised-bed planting system (FIRBS) represents a major shift in the production practices for attaining optimal water productivity in the rice–wheat system in the Indo-Gangetic Plains of South Asia. Information on weed management in dry-seeded rice in the FIRBS is lacking. Two experiments were conducted for 2 years, with an objective

Samar Singh; Lav Bhushan; J. K. Ladha; R. K. Gupta; A. N. Rao; B. Sivaprasad

2006-01-01

230

Root development of F1 rice hybrid and parents as affected by nitrogen concentration of culture solution  

Microsoft Academic Search

Nitrogen (N) nutrition is the major factor involved in attaining high yield in rice (Oryza sativa L.). This study was conducted to elucidate the relationship between the ammonium-N concentration of the culture solution and the root system development of F1 rice hybrid and parents. The rice plants were grown in culture solutions at 0.2, 2, and 20 mg L of

Hiroshi Hasegawa; Tadao Kon; Yasuhiro Kono

1994-01-01

231

Global climate change, rice productivity and methane emissions: comparison of simulated and experimental results  

Microsoft Academic Search

Irrigated rice production is a major food source for a large portion of the world’s population, and a major anthropogenic source of the greenhouse gas methane (CH4). Potential impacts of global climate change [elevated carbon dioxide (CO2) and\\/or elevated temperature] on rice can be predicted with simulation models, but experiments are necessary to determine how well these models mimic the

D. M Olszyk; H. G. S Centeno; L. H Ziska; J. S Kern; R. B Matthews

1999-01-01

232

Coral Reef Ecosystems  

NSDL National Science Digital Library

The Coral Reef Ecosystems SciPack explores the unique and diverse ecosystem of the coral reef. The focus is on Standards and Benchmarks related to populations and ecosystems using coral reefs and their immediate environment as an example. Because the Standards and Benchmarks present the concepts of populations and ecosystems generically, without reference to a specific ecosystem or the organisms in the system, coral reefs are used to provide the context through which concepts in a marine ecosystem are explored.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:� Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. � Access to one-on-one support via e-mail to content "Wizards".� Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Coral Reef Ecosystems: The Living Reef� Identify coral polyp structures and describe their functions.� Describe photosynthesis in the coral environment.� Describe the evolution of a typical reef system.� Use the shape of an individual coral to identify its common name, and classify entire coral reef ecosystems based on shape and location. � Describe the process of coral polyp reproduction and growth.� Identify how the features and/or behavioral strategies of coral reef inhabitants enable them to survive in coral reef environments.Coral Reef Ecosystems: The Abiotic Setting� Identify the characteristics of an ecosystem, and describe the interdependence between biotic and abiotic features in an ecosystem.� Describe how the following abiotic factors provide coral with the energy needed to survive and grow within their ecosystem: sunlight, water, oxygen, and carbon dioxide.� Describe the optimal environmental conditions for coral reef growth, and explain the process of coral reef development (including the role of available sunlight and calcium).� Explain how the following environmental factors might affect coral ecosystems: increase in dissolved CO2, changes in global temperatures, increase in ocean water turbidity through water pollution.Coral Reef Ecosystems: Interdependence� Identify and label key components of food chains and food webs in a coral reef ecosystem.� Describe key relationships among plants and animals in the coral reef ecosystem: predator and prey relationships, producer and consumer relationships, and symbiotic relationships (mutualism, commensalisms, parasitism).� Recognize the direction that energy travels through food chains and food webs.� Explain that materials (chemical elements) and natural resources are recycled in coral reef ecosystems and reappear in different forms.� Describe the primary ecological succession events within a typical coral reef ecosystem.Coral Reef Ecosystems: Ecosystems in Crisis� Describe ways in which human activities directly impact coral reef ecosystems (resource and recreational uses).� Describe ways in which human activities indirectly impact coral reef ecosystems (by changing the physical conditions, pollution, changes in the water chemistry, etc.).� Explain how human activity may decrease the reefs ability to recover from natural occurrences. � Explain the effects of increased predation or disease on a reef ecosystem.� Describe the effect of habitat loss on the reef ecosystem.� Describe the effects of weather and climate change on a healthy and weakened reef ecosystem.

National Science Teachers Association (NSTA)

2007-03-28

233

Ethylene—A key regulator of submergence responses in rice  

Microsoft Academic Search

Ethylene is a major regulator of submergence responses in rice (Oryza sativa). This gaseous phytohormone rapidly accumulates in tissues of submerged plants due to physical entrapment and active biosynthesis during the stress, triggering a range of acclimation responses including shoot elongation, adventitious root formation and carbohydrate metabolism. In addition, ethylene coordinates the balance of gibberellic acid (GA) and abscisic acid

Takeshi Fukao; Julia Bailey-Serres

2008-01-01

234

Simultaneous Process Reengineering and System Replacement at Rice University.  

ERIC Educational Resources Information Center

Describes how Rice University (Texas) simultaneously developed a streamlined client-responsive set of student services while replacing an antiquated information system. Emphasis is on how proper management and careful staging of major changes can result in extremely positive, cost-effective results. (Author/DB)

Hochstettler, Thomas J.; McFarland, Barry P.; Martin, Andrea; Watters, Joseph A., Jr.

1999-01-01

235

SOLID MECHANICS James R. Rice  

E-print Network

1 SOLID MECHANICS James R. Rice School of Engineering and Applied Sciences, and Department of Earth: February 2010 Downloadable at: http://esag.harvard.edu/rice/e0_Solid_Mechanics_94_10.pdf TABLE OF CONTENTS well below those of the application or phenomenon of interest. Solid mechanics is concerned

236

RICE UNIVERSITY Effective Static Debugging  

E-print Network

RICE UNIVERSITY Effective Static Debugging via Componential Set­Based Analysis by Cormac Flanagan of Computer Science J. E. Dennis Noah Harding Professor of Computational and Applied Mathematics Houston on my committee. My research environment at Rice was valuably enriched by my collogues

237

Advances in Transgenic Rice Biotechnology  

Microsoft Academic Search

Rice is the most amenable crop plant for genetic manipulation amongst monocots due to its small genome size, enriched genetic map, availability of entire genome sequence, and relative ease of transformation. Improvement in agronomic traits of rice is bound to affect a sizeable population since it is a primary source of sustenance. Recent advances like use of ‘clean gene’ technology

Hitesh Kathuria; Jitender Giri; Himani Tyagi; Akhilesh K. Tyagi

2007-01-01

238

Rice Boulevard Track/Soccer  

E-print Network

Timeline Banners: A walking history tour The university has installed 100 banners around the campus Tudor Fieldhouse #12;Rice University Centennial Timeline Banners: A walking history tour 1891 Benefactor The first Rice football team is formed. 1913 The first baseball team is formed. 1914 Renowned Oxford

Mellor-Crummey, John

239

Emergy and ecosystem complexity  

NASA Astrophysics Data System (ADS)

The question "What drives complexity?" is addressed in this paper. To answer this question, we explore the way energy and material resources of different quality flow through ecosystems and support, directly and indirectly, ecosystems growth and development. Processes of resource transformation throughout the ecosystem build order, cycle materials, generate and sustain information. Energy drives all these processes and energetic principles explain much of what is observed, including energy degradation according to the laws of thermodynamics. Emergy, a quantitative measure of the global environmental work supporting ecosystem dynamics, is used here in order to provide a deeper understanding of complexity growth and decline in ecosystems. Ecosystem complexity is discussed in this paper in relation to changes in structure, organization and functional capacity, as explained by changes in emergy, empower, and transformity.

Ulgiati, Sergio; Brown, Mark T.

2009-01-01

240

Multiple states in river and lake ecosystems.  

PubMed Central

Nonlinear models of ecosystem dynamics that incorporate positive feedbacks and multiple, internally reinforced states have considerable explanatory power. However, linear models may be adequate, particularly if ecosystem behaviour is primarily controlled by external processes. In lake ecosystems, internal (mainly biotic) processes are thought to have major impacts on system behaviour, whereas in rivers, external (mainly physical) factors have traditionally been emphasized. We consider the hypothesis that models that exhibit multiple states are useful for understanding the behaviour of lake ecosystems, but not as useful for understanding stream ecosystems. Some of the best-known examples of multiple states come from lake ecosystems. We review some of these examples, and we also describe examples of multiple states in rivers. We conclude that the hypothesis is an oversimplification; the importance of physical forcing in rivers does not eliminate the possibility of internal feedbacks that create multiple states, although in rivers these feedbacks are likely to include physical as well as biotic processes. Nonlinear behaviour in aquatic ecosystems may be more common than current theory indicates. PMID:12079525

Dent, C Lisa; Cumming, Graeme S; Carpenter, Stephen R

2002-01-01

241

Ecosystem Services - Water Purification  

NSDL National Science Digital Library

This lesson, provided by Science NetLinks, teaches students the importance of healthy ecosystems by investigating the example of natural water purification. Students will learn how ecosystems remove pollution from the water and how much it costs humans to do this artificially once ecosystems are no longer healthy. The class will then create a "River Newspaper" reporting on the condition of the local environment.

Science Netlinks;

2002-06-30

242

Baltic Ecosystem Adaptive Management  

E-print Network

1 Baltic Ecosystem Adaptive Management �stersjöforskning för en hållbar förvaltning av havet #12;2 Baltic Ecosystem Adaptive Management, BEAM, är ett tvärvetenskapligt forskningsprogram med målet att vårt unika innanhav beror mycket på hur vi väljer att vårda det. Baltic Ecosystem Adaptive Management

243

Photodegradation of Imidacloprid and Fipronil in Rice–Paddy Water  

Microsoft Academic Search

Photodegradation of insecticides, imidacloprid and fipronil, in rice–paddy water under the ambient temperature was investigated.\\u000a The initial concentrations were set at 58.8 and 3.1 ?g\\/L for imidacloprid and fipronil, respectively, according to their reported\\u000a initial concentrations in the rice–paddy field. The half-lives (DT50) of imidacloprid and fipronil were 24.2 and 36.7 h, respectively. Fipronil desulfinyl was detected as a major metabolite\\u000a and

Dang Quoc Thuyet; Hirozumi Watanabe; Kenichi Yamazaki; Kazuhiro Takagi

2011-01-01

244

Major Programs  

Cancer.gov

The Division of Cancer Prevention supports major scientific collaborations and research networks at more than100 sites across the United States; investigator-initiated grants; postdoctoral training; and specialized resources for researchers.

245

Impact of agronomic practices on arsenic accumulation and speciation in rice grain.  

PubMed

Rice is a major source of dietary arsenic (As). The effects of paddy water management, straw incorporation, the applications of nitrogen fertilizer or organic manure, and the additions of biochar on arsenic accumulation and speciation in rice grain were investigated under field conditions over four cropping seasons in Hunan, China. Treatments that promoted anaerobic conditions in the soil, including continuous flooding and straw incorporation, significantly increased the concentration of As, especially methylated As species, in rice grain, whereas N application rate and biochar additions had little or inconsistent effect. Continuous flooding and straw incorporation also increased the abundance of the arsenite methyltransferase gene arsM in the soil, potentially enhancing As methylation in the soil and the uptake of methylated As by rice plants. Intermittent flooding was an effective method to decrease As accumulation in rice grain. PMID:25150455

Ma, Rui; Shen, Jianlin; Wu, Jinshui; Tang, Zhong; Shen, Qirong; Zhao, Fang-Jie

2014-11-01

246

Rice-Map: a new-generation rice genome browser  

PubMed Central

Background The concurrent release of rice genome sequences for two subspecies (Oryza sativa L. ssp. japonica and Oryza sativa L. ssp. indica) facilitates rice studies at the whole genome level. Since the advent of high-throughput analysis, huge amounts of functional genomics data have been delivered rapidly, making an integrated online genome browser indispensable for scientists to visualize and analyze these data. Based on next-generation web technologies and high-throughput experimental data, we have developed Rice-Map, a novel genome browser for researchers to navigate, analyze and annotate rice genome interactively. Description More than one hundred annotation tracks (81 for japonica and 82 for indica) have been compiled and loaded into Rice-Map. These pre-computed annotations cover gene models, transcript evidences, expression profiling, epigenetic modifications, inter-species and intra-species homologies, genetic markers and other genomic features. In addition to these pre-computed tracks, registered users can interactively add comments and research notes to Rice-Map as User-Defined Annotation entries. By smoothly scrolling, dragging and zooming, users can browse various genomic features simultaneously at multiple scales. On-the-fly analysis for selected entries could be performed through dedicated bioinformatic analysis platforms such as WebLab and Galaxy. Furthermore, a BioMart-powered data warehouse "Rice Mart" is offered for advanced users to fetch bulk datasets based on complex criteria. Conclusions Rice-Map delivers abundant up-to-date japonica and indica annotations, providing a valuable resource for both computational and bench biologists. Rice-Map is publicly accessible at http://www.ricemap.org/, with all data available for free downloading. PMID:21450055

2011-01-01

247

Comparative cytological and transcriptomic analysis of pollen development in autotetraploid and diploid rice.  

PubMed

Autotetraploid rice has greater genetic variation and higher vigor than diploid rice, but low pollen fertility is one of the major reasons for low yield of autotetraploid rice. Very little is known about the molecular mechanisms of low pollen fertility of autotetraploid rice. In this study, cytological observations and microarray analysis were used to assess the genetic variation during pollen development in autotetraploid and diploid rice. Many abnormal chromosome behaviors, such as mutivalents, lagged chromosomes, asynchronous cell division, and so on, were found during meiosis in autotetraploid. Microsporogenesis and microgametogenesis in autotetraploid rice was similar to diploid rice, but many different kinds of abnormalities, including microspores degeneration, multi-aperture, and abnormal cell walls, were found in autotetraploid rice. Compared with diploid rice, a total of 1,251 genes were differentially expressed in autotetraploid rice in pollen transcriptome, among them 1,011 and 240 genes were up-regulated and down-regulated, respectively. 124 and 6 genes were co-up-regulated and co-down-regulated during three pollen development stages, respectively. These results suggest that polyploidy induced up-regulation for most of the genes during pollen development. Quantitative RT-PCR was done to validate 12 differentially expressed genes selected from functional categories based on the gene ontology analysis. These stably expressed genes not only related to the pollen development genes, but also involved in cell metabolism, cell physiology, binding, catalytic activity, molecular transducer activity, and transcription regulator activity. The present study suggests that differential expression of some key genes may lead to complex gene regulation and abnormal pollen development in autotetraploid rice. PMID:25262386

Wu, Jinwen; Shahid, Muhammad Qasim; Guo, Haibin; Yin, Wei; Chen, Zhixiong; Wang, Lan; Liu, Xiangdong; Lu, Yonggen

2014-12-01

248

Parallel Computing for Terrestrial Ecosystem Carbon Modeling  

SciTech Connect

Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO{sub 2}. The influence of terrestrial ecosystems on atmospheric CO{sub 2} can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO{sub 2} concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO{sub 2} uptake and respiratory CO{sub 2} release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change impact analysis.

Wang, Dali [ORNL; Post, Wilfred M [ORNL; Ricciuto, Daniel M [ORNL; Berry, Michael [University of Tennessee, Knoxville (UTK)

2011-01-01

249

Coral Reef Ecosystems  

NASA Astrophysics Data System (ADS)

Coral reefs are geological structures of significant dimensions, constructed over millions of years by calcifying organisms. The present day reef-builders are hard corals belonging to the order Scleractinia, phylum Cnidaria. The greatest concentrations of coral reefs are in the tropics, with highest levels of biodiversity situated in reefs of the Indo-West Pacific region. These ecosystems have provided coastal protection and livelihood to human populations over the millennia. Human activities have caused destruction of these habitats, the intensity of which has increased alarmingly since the latter decades of the twentieth century. The severity of this impact is directly related to exponential growth rates of human populations especially in the coastal areas of the developing world. However, a more recently recognized phenomenon concerns disturbances brought about by the changing climate, manifested mainly as rising sea surface temperatures, and increasing acidification of ocean waters due to greater drawdown of higher concentrations of atmospheric carbon dioxide. Management efforts have so far not kept pace with the rates of degradation, so that the spatial extent of damaged reefs and the incidences of localized extinction of reef species are increasing year after year. The major management efforts to date consist of establishing marine protected areas and promoting the active restoration of coral habitats.

Yap, Helen T.

250

[Exposure degree of important non-target arthropods to Cry2Aa in Bt rice fields].  

PubMed

Based on the principle of "risk = hazard x exposure", the selected representative nontarget organisms in the assessment of the potential effects of insect-resistant genetically modified (GM) crops on non-target arthropods in laboratory are generally the arthropod species highly exposed to the insecticidal proteins expressed by the GM crops in farmland ecosystem. In order to understand the exposure degree of the important arthropod species to Cry proteins in Bt rice fields, and to select the appropriate non-target arthropods in the risk assessment of insect-resistant GM crops, the enzyme-linked immunosorbent assay (ELISA) was conducted to measure the Cry2Aa protein concentration in the arthropods collected from the cry2Aa rice fields at different rice growth stages. The results showed that there was a significant difference in the Cry2Aa content protein concentration in different arthropod species. Some species did not contain Cry2Aa protein, while some species contained larger amounts of Cry2Aa protein. Relative to the arthropods colleted after rice anthesis, the arthropods colleted in rice anthesis contained relative higher concentrations of Cry2Aa protein, especially for the predacious arthropods. No Cry proteins were detected in parasitic arthropods. This study provided references for the laboratory assessment of the effects of GM rice on nontarget arthropods. PMID:24066553

Zhang, Qing-Ling; Li, Yun-He; Hua, Hong-Xia; Yang, Chang-Ju; Wu, Hong-Jin; Peng, Yu-Fa

2013-06-01

251

Expressing ScACR3 in rice enhanced arsenite efflux and reduced arsenic accumulation in rice grains.  

PubMed

Arsenic (As) accumulation in rice grain poses a serious health risk to populations with high rice consumption. Extrusion of arsenite [As(III)] by ScAcr3p is the major arsenic detoxification mechanism in Saccharomyces cerevisiae. However, ScAcr3p homolog is absent in higher plants, including rice. In this study, ScACR3 was introduced into rice and expressed under the control of the Cauliflower mosaic virus (CaMV) 35S promoter. In the transgenic lines, As concentrations in shoots and roots were about 30% lower than in the wild type, while the As translocation factors were similar between transgenic lines and the wild type. The roots of transgenic plants exhibited significantly higher As efflux activities than those of the wild type. Within 24 h exposure to 10 ?M arsenate [As(V)], roots of ScACR3-expressing plants extruded 80% of absorbed As(V) to the external solution as As(III), while roots of the wild type extruded 50% of absorbed As(V). Additionally, by exposing the As-containing rice plants to an As-lacking solution for 24 h, about 30% of the total As derived from pre-treatment was extruded to the external solution by ScACR3-expressing plants, while about 15% of As was extruded by wild-type plants. Importantly, ScACR3 expression significantly reduced As accumulation in rice straws and grains. When grown in flooded soil irrigated with As(III)-containing water, the As concentration in husk and brown rice of the transgenic lines was reduced by 30 and 20%, respectively, compared with the wild type. This study reports a potential strategy to reduce As accumulation in the food chain by expressing heterologous genes in crops. PMID:22107880

Duan, Guilan; Kamiya, Takehiro; Ishikawa, Satoru; Arao, Tomohito; Fujiwara, Toru

2012-01-01

252

International Consortium of Rice Mutagenesis: resources and beyond  

PubMed Central

Rice is one of the most important crops in the world. The rice community needs to cooperate and share efforts and resources so that we can understand the functions of rice genes, especially those with a role in important agronomical traits, for application in agricultural production. Mutation is a major source of genetic variation that can be used for studying gene function. We will present here the status of mutant collections affected in a random manner by physical/chemical and insertion mutageneses. As of early September 2013, a total of 447, 919 flanking sequence tags from rice mutant libraries with T-DNA, Ac/Ds, En/Spm, Tos17, nDART/aDART insertions have been collected and publicly available. From these, 336,262 sequences are precisely positioned on the japonica rice chromosomes, and 67.5% are in gene interval. We discuss the genome coverage and preference of the insertion, issues limiting the exchange and use of the current collections, as well as new and improved resources. We propose a call to renew all mutant populations as soon as possible. We also suggest that a common web portal should be established for ordering seeds. PMID:24341871

2013-01-01

253

Rice crop duration and leaf appearance rate in a variable thermal environment. III. Heritability of photothermal traits  

Microsoft Academic Search

In arid, irrigated, rice environments, crop duration is highly variable, resulting in uncertain crop calendars for double cropping. The main causes of this variability are varying temperature and daylength. Breeding for stable crop duration in such environments might make a major contribution to rice production. A previous study established genetic differences in phenological responses to temperature and photoperiod, based on

M Sié; M Dingkuhn; M. C. S Wopereis; K. M Miezan

1998-01-01

254

Ecosystems, Teacher's Guide.  

ERIC Educational Resources Information Center

The Science Curriculum Improvement Study has developed this teacher's guide to "Ecosystems," the sixth part of a six unit life science curriculum sequence. The six basic units, emphasizing organism-environment interactions, are organisms, life cycles, populations, environments, communities, and ecosystems. They make use of scientific and…

California Univ., Berkeley. Science Curriculum Improvement Study.

255

Exploring virtual ecosystems  

Microsoft Academic Search

Browsing In Time & Space (BITS) is an interface designed to explore virtual ecosystems. A virtual ecosystem includes a three dimensional terrain model background, collections of man-made and natural objects, and behavior and interaction rules between the objects and the background. BITS is based on a virtual notepad and pen metaphor and is inspired in the concept of logging. Physical

Antão Vaz Almada; António Eduardo Dias; João Pedro Silva; Emanuel Marques dos Santos; Pedro José Pedrosa; António Sousa Câmara

1996-01-01

256

Graduate studies Ecosystem Science  

E-print Network

Graduate studies in Ecosystem Science and Management Ph.D. M.S. M.Agr. or Natural Resources Development MNRD Department of Ecosystem Science and Management College of Agriculture and Life Sciences. The thesisbased Master of Science and Ph.D. degrees are designed for research or academic careers

257

Earth on Edge : Ecosystems  

NSDL National Science Digital Library

This site provides information about the six ecosystems on which life on Earth most heavily depends: agricultural, forest, freshwater, grassland, coastal, and urban. It is part of a Public Broadcasting System (PBS) project, which includes a discussion guide. Ecosystems are described as communities of interacting organisms and the physical environment in which they live. The goods and services that ecosystems provide are said to form the foundation of human economies. Ecosystems purify air and water, help to control climate, and produce valuable soil-services. Site users may access a discussion guide to accompany the broadcast of the video/television program, which can be used in colleges, secondary schools, and in community groups. Case studies are taken from the companion book, World Resources 2000-2001: Ecosystems and People: The Fraying Web of Life, and from Pilot Analysis of Global Ecosystems: Agroecosystems (World Resources Institute). This online text includes profiles, case studies, and ecosystem assessments with references to ecosystems around the world. A list of additional resources includes links to environmental organizations, books, and periodicals.

Mock, Gregory; Vanasselt, Wendy

2000-01-01

258

The Library as Ecosystem  

ERIC Educational Resources Information Center

Ecology is the study of interactions between organisms and their environment, and the academic library could be considered to be an ecosystem, i.e., a "biological organization" in which multiple species must interact, both with one another and with their environment. The metaphor of the library as ecosystem is flexible enough to be applied not…

Walter, Scott

2008-01-01

259

Ecosystems, externalities, and economies  

Microsoft Academic Search

This paper incorporates an ecosystem model into a model of a simple economy. The decisionmaking agents in the ecosystem are individual organisms aggregated to the species level. A species may provide utility directly to humans, or it may provide utility indirectly because it is used either as a raw material in goods fabrication or as sustenance for other species. We

Thomas D. Crocker; John Tschirhart

1992-01-01

260

SAR Agriculture Rice Production Estimation (SARPE)  

NASA Astrophysics Data System (ADS)

The study of SAR Agriculture Rice Production Estimation (SARPE) was held in Indonesia on 2012, as part of Asia-Rice Crop Estimation & Monitoring (Asia-RiCE), which is a component for the GEO Global Agricultural Monitoring (GEOGLAM) initiative. The study was expected to give a breakthrough result, by using radar technology and paradigm shift of the standard production estimation system from list frame to area frame approach. This initial product estimation system is expected to be refined (fine tuning) in 2013, by participating as part of Technical Demonstration Site (Phase -1A) of Asia-RICE. The implementation period of this initial study was from the date of March 12 to December 10, 2012. The implementation of the study was done by following the approach of the BIMAS-21 framework, which has been developed since 2008. The results of this study can be briefly divided into two major components, namely: Rice-field Baseline Mapping (PESBAK - Peta Sawah Baku) and Crop Growth Monitoring. Rice-fields were derived from the mapping results of the Ministry of Agriculture (Kemtan), and validated through Student Extension Campaign of the Faculty of Agriculture, Bogor Agricultural University (IPB). While for the crop growth, it was derived from the results of image analysis process. The analysis was done, either on radar/Radarsat-2 (medium resolution) or optical/ MODIS (low resolution), based on the Planting Calendar (KATAM) of Kemtan. In this case, the planting season II/2012-2013 of rice production centers in West Java Province (Karawang, Subang and Indramayu counties). The selection of crop season and county were entirely dependent on the quality of the available PESBAK and procurement process of radar imagery. The PESBAK is still in the form of block instead of fields, so it can not be directly utilized in this study. Efforts to improve the PESBAK can not be optimal because the provided satellite image (ECW format) is not the original one. While the procurement process of SAR imageries, determine the target planting season to be linked. In this case the radar image only acquired two time series: the date of 26/10/2012 (stripmap) and 10/31/2012 (scanSAR) for series-1, and the date of 19/11/2012 (stripmap) and 11/24/2012 ( scanSAR) for series-2. The end result of this study is a model of crop growth status at the village, district and county level compared to KATAM. The County of Subang was used as a pilot exercise, and then was replicated into the two other counties (Karawang and Indramayu). Status of plant growth is divided into five phases: fallow wet, young vegetation, old vegetation, generative (pre-harvest), and dry fallow. The process of plant growth status was started with the determination of the majority in each rice field as a benchmark. This was followed by the creation of status recapitulation at the village, district, and ultimately at the county level. The county results were then compared with KATAM. Further replication to the rest of the other counties in the West Java Province, can only be done after the related PESBAK was improved in accordance to the area base standard requirement.

Raimadoya, M.

2013-12-01

261

An SNP Caused Loss of Seed Shattering During Rice Domestication  

Microsoft Academic Search

Loss of seed shattering was a key event in the domestication of major cereals. We revealed that the qSH1 gene, a major quantitative trait locus of seed shattering in rice, encodes a BEL1-type homeobox gene and demonstrated that a single-nucleotide polymorphism (SNP) in the 5' regulatory region of the qSH1 gene caused loss of seed shattering owing to the absence

Saeko Konishi; Takeshi Izawa; Shao Yang Lin; Kaworu Ebana; Yoshimichi Fukuta; Takuji Sasaki; Masahiro Yano

2006-01-01

262

Isotopic disequilibrium between carbon assimilated and respired in a rice paddy as influenced by methanogenesis from CO2  

Microsoft Academic Search

Temporal variability in the carbon isotope composition of ecosystem respiration (?R) has been closely related to environmental variables that influence photosynthetic isotope discrimination (?). We show that belowground methanogenesis has a strong impact on ?R and leads to a partial decoupling between ?R and ?. The ?R, observed in a Japanese rice paddy, varied from ?26.3‰ to ?22.8‰ over the

G. H. Han; H. Yoshikoshi; H. Nagai; T. Yamada; K. Ono; M. Mano; A. Miyata

2007-01-01

263

Ecosystem Viable Yields  

E-print Network

The World Summit on Sustainable Development (Johannesburg, 2002) encouraged the application of the ecosystem approach by 2010. However, at the same Summit, the signatory States undertook to restore and exploit their stocks at maximum sustainable yield (MSY), a concept and practice without ecosystemic dimension, since MSY is computed species by species, on the basis of a monospecific model. Acknowledging this gap, we propose a definition of "ecosystem viable yields" (EVY) as yields compatible i) with biological viability levels for all time and ii) with an ecosystem dynamics. To the difference of MSY, this notion is not based on equilibrium, but on viability theory, which offers advantages for robustness. For a generic class of multispecies models with harvesting, we provide explicit expressions for the EVY. We apply our approach to the anchovy--hake couple in the Peruvian upwelling ecosystem between the years 1971 and 1981.

De Lara, Michel; Oliveros-Ramos, Ricardo; Tam, Jorge

2011-01-01

264

Allelic diversities in rice starch biosynthesis lead to a diverse array of rice eating and cooking qualities  

PubMed Central

More than half of the world's population uses rice as a source of carbon intake every day. Improving grain quality is thus essential to rice consumers. The three main properties that determine rice eating and cooking quality—amylose content, gel consistency, and gelatinization temperature—correlate with one another, but the underlying mechanism of these properties remains unclear. Through an association analysis approach, we found that genes related to starch synthesis cooperate with each other to form a fine regulating network that controls the eating and cooking quality and defines the correlation among these three properties. Genetic transformation results verified the association findings and also suggested the possibility of developing elite cultivars through modification with selected major and/or minor starch synthesis-related genes. PMID:20018713

Tian, Zhixi; Qian, Qian; Liu, Qiaoquan; Yan, Meixian; Liu, Xinfang; Yan, Changjie; Liu, Guifu; Gao, Zhenyu; Tang, Shuzhu; Zeng, Dali; Wang, Yonghong; Yu, Jianming; Gu, Minghong; Li, Jiayang

2009-01-01

265

Ecosystem Restoration through Interdisciplinary Exchange  

E-print Network

Ecosystem Restoration through Interdisciplinary Exchange David M. Blersch dblersch Shade of Blue and You 21 September 2010 #12;National Science Foundation Ecosystem Restoration through;National Science Foundation Ecosystem Restoration through Interdisciplinary Exchange UB's ERIE Program www

Sachs, Frederick

266

SEVEN PILLARS OF ECOSYSTEM MANAGEMENT  

EPA Science Inventory

Ecosystem management is widely proposed in the popular and professional literature as the modern and preferred way of managing natural resources and ecosystems. Advocates glowingly describe ecosystem management as an approach that will protect the environment, maintain healthy ec...

267

Major depression.  

PubMed

Major depression is a common, disabling condition seen frequently in primary care practices. Non-psychiatrist ambulatory providers are increasingly responsible for diagnosing, and primarily managing patients suffering from major depressive disorder (MDD). The goal of this review is to help primary care providers to understand the natural history of MDD, identify practical tools for screening, and a thoughtful approach to management. Clinically challenging topics like co-morbid conditions, treatment resistant depression and pharmacotherapy selection with consideration to side effects and medication interactions, are also covered. PMID:25134869

Bentley, Susan M; Pagalilauan, Genevieve L; Simpson, Scott A

2014-09-01

268

Habitat scale mapping of fisheries ecosystem services values in estuaries  

EPA Science Inventory

Little is known about the variability of ecosystem service values at spatial scales most relevant to local decision makers. Competing definitions of ecosystem services, the paucity of ecological and economic information and the lack of standardization in methodology are major ob...

269

Trophic cascades across ecosystems Tiffany M. Knight1,2  

E-print Network

histories often shift habitats during their life cycles7 and provide potent conduits coupling ecosystems5 of a cascade of species interactions, mediated by dragonflies switching during their life history between ecosystem bound- aries can have major consequences for community dynamics5,6 . Species with complex life

Gottgens, Hans

270

Assessing the functional implications of soil biodiversity in ecosystems  

Microsoft Academic Search

Soil communities are among the most species-rich components of terrestrial ecosystems. A major challenge for soil ecologists is to formulate feasible research strategies that will preserve and capitalize on the biodiversity resources of the soil. This article considers the role of soil organism diversity by concentrating on: (i) the relationship between soil biodiversity and ecosystem function; (ii) what issues need

Thomas Hefin Jones; Mark Alexander Bradford

2001-01-01

271

Increasing herbicide selectivity between rice and red rice  

E-print Network

and lower organic matter of the soil used by Eastin could have effectively increased the herbi- cide concentration available in the soil which could have caused the high level of injury. NA has been shown to protect rice against several herbicides... and lower organic matter of the soil used by Eastin could have effectively increased the herbi- cide concentration available in the soil which could have caused the high level of injury. NA has been shown to protect rice against several herbicides...

Koetz, Paul Howard

2012-06-07

272

Coral Reef Ecosystems: Interdependence  

NSDL National Science Digital Library

This Science Object is the third of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the interdependent relationships between species in the coral reef ecosystem. All populations in the reef ecosystem are a part of and depend on a global food web (a connected set of food chains) through which energy flows in one direction, from the sun into organism and eventually dissipating into the environment as heat. This food web includes ocean plants, the animals that feed on them, and the animals that feed on those animals. Energy is transferred between organisms and their environment along the way. Energy concentration diminishes at each step. The cycles of life continue indefinitely because organisms decompose after death and return food materials to the environment. Learning Outcomes:� Identify and label key components of food chains and food webs in a coral reef ecosystem.� Describe key relationships among plants and animals in the coral reef ecosystem: predator and prey relationships, producer and consumer relationships, and symbiotic relationships (mutualism, commensalisms, parasitism).� Recognize the direction that energy travels through food chains and food webs.� Explain that materials (chemical elements) and natural resources are recycled in coral reef ecosystems and reappear in different forms.� Describe the primary ecological succession events within a typical coral reef ecosystem.

National Science Teachers Association (NSTA)

2006-11-01

273

Role of fungi in marine ecosystems  

Microsoft Academic Search

Marine fungi are an ecological rather than a taxonomic group and comprise an estimated 1500 species, excluding those that form lichens. They occur in most marine habitats and generally have a pantropical or pantemperate distribution. Marine fungi are major decomposers of woody and herbaceous substrates in marine ecosystems. Their importance lies in their ability to aggressively degrade lignocellulose. They may

Kevin D. Hyde; E. B. Gareth Jones; Eduardo Leaño; Stephen B. Pointing; Asha D. Poonyth; Lilian L. P. Vrijmoed

1998-01-01

274

Relevance of antarctic microbial ecosystems to exobiology  

NASA Technical Reports Server (NTRS)

Antarctic microbial ecosystems which provide biological and physical analogs that can be used in exobiology are studied. Since the access to extraterrestrial habitats is extremely difficult, terrestrial analogs represent the best opportunity for both formulation and preliminary testing of hypothesis about life. Antarctica, as one of few suitable environments on earth is considered to be a major locus of progress in exobiology.

Mckay, Christopher P.

1993-01-01

275

MERCURY IN LAKE MICHIGAN ECOSYSTEM COMPONENTS  

EPA Science Inventory

Mercury is a toxic bioaccumulative substance in aquatic ecosystems. National fish advisories for mercury increased 115% from 1993 to 2001 and fish consumption is now a major health concern. The Lake Michigan Mass Balance Study measured the concentrations of mercury in the atmosph...

276

El Niño effects on the dynamics of terrestrial ecosystems.  

PubMed

New studies are showing that the El Niño Southern Oscillation (ENSO) has major implications for the functioning of different ecosystems, ranging from deserts to tropical rain forests. ENSO-induced pulses of enhanced plant productivity can cascade upward through the food web invoking unforeseen feedbacks, and can cause open dryland ecosystems to shift to permanent woodlands. These insights suggest that the predicted change in extreme climatic events resulting from global warming could profoundly alter biodiversity and ecosystem functioning in many regions of the world. Our increasing ability to predict El Niño effects can be used to enhance management strategies for the restoration of degraded ecosystems. PMID:11165707

Holmgren, M; Scheffer, M; Ezcurra, E; Gutiérrez, J R.; Mohren, G M.J.

2001-02-01

277

Interactions among rice ORC subunits.  

PubMed

The origin recognition complex (ORC) is composed of six subunits and plays an important role in DNA replication in all eukaryotes. The ORC subunits OsORC6 as well as the other five ORC subunits in rice were experimentally isolated and sequenced. It indicated that there also exist six ORC subunits in rice. Results of RT-PCR indicated that expression of all the rice ORC genes are no significant difference under 26°C and 34°C. Yeast two hybridization indicated that OsORC2, -3, -5 interact with each other. OsORC5 can then bind OsORC4 to form the OsORC2, -3,-4,-5 core complex. It suggested that the basic interactions have been conserved through evolution. No binding of OsORC1 and OsORC6 with the other subunits were observed. A model of ORC complex in rice is proposed. PMID:23733064

Tan, Deyong; Lv, Qundan; Chen, Xinai; Shi, Jianghua; Ren, Meiyan; Wu, Ping; Mao, Chuanzao

2013-08-01

278

Interactions among rice ORC subunits  

PubMed Central

The origin recognition complex (ORC) is composed of six subunits and plays an important role in DNA replication in all eukaryotes. The ORC subunits OsORC6 as well as the other five ORC subunits in rice were experimentally isolated and sequenced. It indicated that there also exist six ORC subunits in rice. Results of RT-PCR indicated that expression of all the rice ORC genes are no significant difference under 26°C and 34°C. Yeast two hybridization indicated that OsORC2, -3, -5 interact with each other. OsORC5 can then bind OsORC4 to form the OsORC2, -3,-4,-5 core complex. It suggested that the basic interactions have been conserved through evolution. No binding of OsORC1 and OsORC6 with the other subunits were observed. A model of ORC complex in rice is proposed. PMID:23733064

Tan, Deyong; Lv, Qundan; Chen, Xinai; shi, Jianghua; Ren, Meiyan; Wu, Ping; Mao, Chuanzao

2013-01-01

279

National Geographic Education: Ecosystems  

NSDL National Science Digital Library

The National Geographic Education website has a number of sections dedicated to different areas within the natural sciences. This particular section brings together all manner of educational resources related to ecosystems. On the site, visitors can dive in via the Latest Updates for Ecosystems. Here they can learn how to explore the profiled ecosystems via a range of GIS tools. Visitors can use the filters on the site to look over the resources by Type, Grades & Ages, Intended Audience, and Subjects. Visitors shouldn't miss looking over features like the Amazon Gold Mine, Back to the Bottom, and African Savanna.

2013-06-13

280

Syrtis Major  

NASA Astrophysics Data System (ADS)

A prominent dark, triangular albedo feature (dark by contrast with its surroundings) on the Martian equator, centered approximately at 10 °N, 70 °E. It takes its name from the historical name for the larger of two quicksands off the North African coast. Syrtis Major is prominent in telescopic views of the planet, and was in fact the first feature of Mars ever to be recorded, in a sketch made by C...

Murdin, P.

2000-11-01

281

Molecular mapping of rice chromosomes  

Microsoft Academic Search

We report the construction of an RFLP genetic map of rice (Oryza sativa) chromosomes. The map is comprised of 135 loci corresponding to clones selected from a PstI genomic library. This molecular map covers 1,389 cM of the rice genome and exceeds the current classical maps by more than 20%. The map was generated from F2 segregation data (50 individuals)

S. R. McCouch; G. Kochert; Z. H. Yu; Z. Y. Wang; G. S. Khush; W. R. Coffman; S. D. Tanksley

1988-01-01

282

Texas Rice, Highlights in Research  

E-print Network

herbicide technology that selec- tively removes red rice from commercial rice without harming the crop. Previously research has indicated that first generation Clearfield cultivars displayed minimal tolerance to Newpath therefore a second generation... was developed and displayed increased tolerance. As new cultivars are developed, research testing tolerance continues to be important. This year we are looking at four new or existing culti- vars, CL-XL745, CL-XL730, CL-XL729, CL171-R, and CL161 testing...

2007-01-01

283

Effects of water management, connectivity, and surrounding land use on habitat use by frogs in rice paddies in Japan.  

PubMed

In Japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. However, since the 1950s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. It is urgently necessary to evaluate rice paddies as habitats for conservation. Among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed the influence of environmental factors on their habitat use. We found four frog species and one subspecies (Hyla japonica, Pelophylax nigromaculatus, Glandirana rugosa, Lithobates catesbeianus, and Pelophylax porosa brevipoda) at our study sites in Shiga prefecture. For all but L. catesbeianus, we analyzed the influence of environmental factors related to rice paddy structure, water management and availability, agrochemical use, connectivity, and land use on breeding and non-breeding habitat use. We constructed generalized additive mixed models with survey date as the smooth term and applied Akaike's information criterion to choose the bestranked model. Because life histories and biological characteristics vary among species, the factors affecting habitat use by frogs are also expected to differ by species. We found that both breeding and non-breeding habitat uses of each studied species were influenced by different combinations of environmental factors and that in most cases, habitat use showed seasonality. For frog conservation in rice paddies, we need to choose favorable rice paddy in relation to surrounding land use and apply suitable management for target species. PMID:22943781

Naito, Risa; Yamasaki, Michimasa; Lmanishi, Ayumi; Natuhara, Yosihiro; Morimoto, Yukihiro

2012-09-01

284

Phenolic profiles and antioxidant activity of black rice bran of different commercially available varieties.  

PubMed

Increased consumption of whole grains has been associated with reduced risk of developing major chronic diseases. These health benefits have been attributed in part to their unique phytochemicals. Previous studies on black rice mainly focused on anthocyanins. Little is known about the phytochemical profiles and antioxidant activities of different black rice varieties. The objective of this study was to determine the phytochemical profiles and antioxidant activity of rice bran samples from 12 diverse varieties of black rice. The free, bound, and total phenolic contents of black rice bran samples ranged from 2086 to 7043, from 221.2 to 382.7, and from 2365 to 7367 mg of gallic acid equiv/100 g of dry weight (DW), respectively. The percentage contribution of free phenolics to the total ranged from 88.2 to 95.6%. The average values of free, bound, and total phenolic contents of black rice bran were 8, 1.5, and 6 times higher than those of white rice bran, respectively (p < 0.05). The free, bound, and total flavonoid contents of black rice bran samples ranged from 3462 to 12061, from 126.7 to 386.9, and from 3596 to 12448 mg of catechin equiv/100 g of DW, respectively. The percentage contribution of free flavonoids to the total ranged from 96.3 to 97.6%. The average values of free, bound, and total flavonoid contents of black rice bran were 7.4, 1.9, and 6.7 times higher than those of white rice bran, respectively (p < 0.05). The free, bound, and total anthocyanin contents of black rice bran samples ranged from 1227 to 5096, from 4.89 to 8.23, and from 1231 to 5101 mg of cyanidin-3-glucoside equiv/100 g of DW, respectively. The percentage contribution of free anthocyanins to the total ranged from 99.5 to 99.9%. Cyanidin-3-glucoside, cyanidin-3-rutinoside, and peonidin-3-glucoside were detected in black rice bran samples and ranged from 736.6 to 2557, from 22.70 to 96.62, and from 100.7 to 534.2 mg/100 g of DW, respectively. The free, bound, and total antioxidant activities of black rice bran samples ranged from 476.9 to 180, from 47.91 to 79.48, and from 537.5 to 1876 mumol of Trolox equiv/g of DW, respectively. The percentage contribution of free antioxidant activity to the total ranged from 88.7 to 96.0%. The average values of free, bound, and total antioxidant activity of black rice bran were more than 8, 1.5, and 6 times higher than those of white rice bran, respectively (p < 0.05). The total antioxidant activity of black rice bran was correlated to the content of total phenolics, total flavonoids, and total anthocyanins and also was significantly correlated to the contents of cyanidin-3-glucoside, cyanidin-3-rutinoside, and peonidin-3-glucoside. These results indicate that there are significant differences in phytochemical content and antioxidant activity among the different black rice varieties. Black rice bran has higher content of phenolics, flavonoids, and anthocyanins and has higher antioxidant activity when compared to white rice bran. Interestingly, the phenolics, flavonoids, and anthocyanins of black rice bran are mainly present in free form. Knowing the phytochemical profile and antioxidant activity of black rice bran gives insights to its potential application to promote health. PMID:20521821

Zhang, Ming Wei; Zhang, Rui Feng; Zhang, Fang Xuan; Liu, Rui Hai

2010-07-14

285

Expansins in deepwater rice internodes.  

PubMed

Cell walls of deepwater rice (Oryza sativa L.) internodes undergo long-term extension (creep) when placed under tension in acidic buffers. This is indicative of the action of the cell wall-loosening protein expansin. Wall extension had a pH optimum of around 4.0 and was abolished by boiling. Acid-induced extension of boiled cell walls could be reconstituted by addition of salt-extracted rice or cucumber cell wall proteins. Cucumber expansin antibody recognized a single protein band of 24.5-kD apparent molecular mass on immunoblots of rice cell wall proteins. Expansins were partially purified by concanavalin A affinity chromatography and sulfopropyl (SP) cation-exchange chromatography. The latter yielded two peaks with extension activity (SP20 and SP29), and immunoblot analysis showed that both of these active fractions contained expansin of 24.5-kD molecular mass. The N-terminal amino acid sequence of SP20 expansin is identical to that deduced from the rice expansin cDNA Os-EXP1. The N-terminal amino acid sequence of SP29 expansin matches that deduced from the rice expansin cDNA Os-EXP2 in six of eight amino acids. Our results show that two expansins occur in the cell walls of rice internodes and that they may mediate acid-induced wall extension. PMID:9112771

Cho, H T; Kende, H

1997-04-01

286

Expansins in deepwater rice internodes.  

PubMed Central

Cell walls of deepwater rice (Oryza sativa L.) internodes undergo long-term extension (creep) when placed under tension in acidic buffers. This is indicative of the action of the cell wall-loosening protein expansin. Wall extension had a pH optimum of around 4.0 and was abolished by boiling. Acid-induced extension of boiled cell walls could be reconstituted by addition of salt-extracted rice or cucumber cell wall proteins. Cucumber expansin antibody recognized a single protein band of 24.5-kD apparent molecular mass on immunoblots of rice cell wall proteins. Expansins were partially purified by concanavalin A affinity chromatography and sulfopropyl (SP) cation-exchange chromatography. The latter yielded two peaks with extension activity (SP20 and SP29), and immunoblot analysis showed that both of these active fractions contained expansin of 24.5-kD molecular mass. The N-terminal amino acid sequence of SP20 expansin is identical to that deduced from the rice expansin cDNA Os-EXP1. The N-terminal amino acid sequence of SP29 expansin matches that deduced from the rice expansin cDNA Os-EXP2 in six of eight amino acids. Our results show that two expansins occur in the cell walls of rice internodes and that they may mediate acid-induced wall extension. PMID:9112771

Cho, H T; Kende, H

1997-01-01

287

Broader perspective on ecosystem sustainability: Consequences for decision making  

PubMed Central

Although the concept of ecosystem sustainability has a long-term focus, it is often viewed from a static system perspective. Because most ecosystems are dynamic, we explore sustainability assessments from three additional perspectives: resilient systems; systems where tipping points occur; and systems subject to episodic resetting. Whereas foundations of ecosystem resilience originated in ecology, recent discussions have focused on geophysical attributes, and it is recognized that dynamic system components may not return to their former state following perturbations. Tipping points emerge when chronic changes (typically anthropogenic, but sometimes natural) push ecosystems to thresholds that cause collapse of process and function and may become permanent. Ecosystem resetting occurs when episodic natural disasters breach thresholds with little or no warning, resulting in long-term changes to environmental attributes or ecosystem function. An example of sustainability assessment of ecosystem goods and services along the Gulf Coast (USA) demonstrates the need to include both the resilient and dynamic nature of biogeomorphic components. Mountain road development in northwest Yunnan, China, makes rivers and related habitat vulnerable to tipping points. Ecosystems reset by natural disasters are also presented, emphasizing the need to understand the magnitude frequency and interrelationships among major disturbances, as shown by (i) the 2011 Great East Japan Earthquake and resulting tsunami, including how unsustainable urban development exacerbates geodisaster propagation, and (ii) repeated major earthquakes and associated geomorphic and vegetation disturbances in Papua New Guinea. Although all of these ecosystem perturbations and shifts are individually recognized, they are not embraced in contemporary sustainable decision making. PMID:23686583

Sidle, Roy C.; Benson, William H.; Carriger, John F.; Kamai, Toshitaka

2013-01-01

288

Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation?  

E-print Network

COMMENTARY Is Net Ecosystem Production Equal to Ecosystem Carbon Accumulation? Gary M. Lovett,* Jonathan J. Cole, and Michael L. Pace Institute of Ecosystem Studies, Millbrook, New York 12545, USA ABSTRACT Net ecosystem production (NEP), defined as the difference between gross primary production

Pace, Michael L.

289

Breeding high-yielding drought-tolerant rice: genetic variations and conventional and molecular approaches.  

PubMed

The increased occurrence and severity of drought stress have led to a high yield decline in rice in recent years in drought-affected areas. Drought research at the International Rice Research Institute (IRRI) over the past decade has concentrated on direct selection for grain yield under drought. This approach has led to the successful development and release of 17 high-yielding drought-tolerant rice varieties in South Asia, Southeast Asia, and Africa. In addition to this, 14 quantitative trait loci (QTLs) showing a large effect against high-yielding drought-susceptible popular varieties were identified using grain yield as a selection criterion. Six of these (qDTY 1.1 , qDTY 2.2 , qDTY 3.1 , qDTY 3.2 , qDTY 6.1 , and qDTY 12.1 ) showed an effect against two or more high-yielding genetic backgrounds in both the lowland and upland ecosystem, indicating their usefulness in increasing the grain yield of rice under drought. The yield of popular rice varieties IR64 and Vandana has been successfully improved through a well-planned marker-assisted backcross breeding approach, and QTL introgression in several other popular varieties is in progress. The identification of large-effect QTLs for grain yield under drought and the higher yield increase under drought obtained through the use of these QTLs (which has not been reported in other cereals) indicate that rice, because of its continuous cultivation in two diverse ecosystems (upland, drought tolerant, and lowland, drought susceptible), has benefited from the existence of larger genetic variability than in other cereals. This can be successfully exploited using marker-assisted breeding. PMID:25205576

Kumar, Arvind; Dixit, Shalabh; Ram, T; Yadaw, R B; Mishra, K K; Mandal, N P

2014-11-01

290

Breeding high-yielding drought-tolerant rice: genetic variations and conventional and molecular approaches  

PubMed Central

The increased occurrence and severity of drought stress have led to a high yield decline in rice in recent years in drought-affected areas. Drought research at the International Rice Research Institute (IRRI) over the past decade has concentrated on direct selection for grain yield under drought. This approach has led to the successful development and release of 17 high-yielding drought-tolerant rice varieties in South Asia, Southeast Asia, and Africa. In addition to this, 14 quantitative trait loci (QTLs) showing a large effect against high-yielding drought-susceptible popular varieties were identified using grain yield as a selection criterion. Six of these (qDTY 1.1, qDTY 2.2, qDTY 3.1, qDTY 3.2, qDTY 6.1, and qDTY 12.1) showed an effect against two or more high-yielding genetic backgrounds in both the lowland and upland ecosystem, indicating their usefulness in increasing the grain yield of rice under drought. The yield of popular rice varieties IR64 and Vandana has been successfully improved through a well-planned marker-assisted backcross breeding approach, and QTL introgression in several other popular varieties is in progress. The identification of large-effect QTLs for grain yield under drought and the higher yield increase under drought obtained through the use of these QTLs (which has not been reported in other cereals) indicate that rice, because of its continuous cultivation in two diverse ecosystems (upland, drought tolerant, and lowland, drought susceptible), has benefited from the existence of larger genetic variability than in other cereals. This can be successfully exploited using marker-assisted breeding. PMID:25205576

Kumar, Arvind; Dixit, Shalabh; Ram, T.; Yadaw, R. B.; Mishra, K. K.; Mandal, N. P.

2014-01-01

291

Analyzing an Ecosystem  

NSDL National Science Digital Library

In this interactive activity adapted from the University of Alberta, identify the living and nonliving things in an ecosystem. Then look further at the living things to identify the producers, the consumers, and examples of mimicry.

Foundation, Wgbh E.

2007-08-09

292

Ecosystems in the Laboratory  

ERIC Educational Resources Information Center

Describes the materials and laboratory techniques for the study of food chains and food webs, pyramids of numbers and biomass, energy pyramids, and oxygen gradients. Presents a procedure for investigating the effects of various pollutants on an entire ecosystem. (GS)

Madders, M.

1975-01-01

293

Genetic engineering approaches to improve the bioavailability and the level of iron in rice grains  

Microsoft Academic Search

Iron deficiency is the most widespread micronutrient deficiency world-wide. A major cause is the poor absorption of iron from\\u000a cereal and legume-based diets high in phytic acid. We have explored three approaches for increasing the amount of iron absorbed\\u000a from rice-based meals. We first introduced a ferritin gene from Phaseolus vulgaris into rice grains, increasing their iron content up to

P. Lucca; R. Hurrell; I. Potrykus

2001-01-01

294

Potential Paddy Rice Yields for Rainfed and Irrigated Agriculture in China and Korea  

Microsoft Academic Search

YIELD, a water-balance and crop-yield model that calculates production and water consumption variables for a variety of major crops, was applied specifically for wetland rice to China and Korea in order to estimate the region's potential and actual yields for irrigated and rainfed rice production. A network of 241 stations provided the climatic data averaged over approximately a 25-year period.

W. H. Terjung; J. T. Hayes; H. Y. Ji; P. E. Todhunter; P. A. ORourke

1985-01-01

295

Natural rice rhizospheric microbes suppress rice blast infections  

PubMed Central

Background The natural interactions between plant roots and their rhizospheric microbiome are vital to plant fitness, modulating both growth promotion and disease suppression. In rice (Oryza sativa), a globally important food crop, as much as 30% of yields are lost due to blast disease caused by fungal pathogen Magnaporthe oryzae. Capitalizing on the abilities of naturally occurring rice soil bacteria to reduce M. oryzae infections could provide a sustainable solution to reduce the amount of crops lost to blast disease. Results Naturally occurring root-associated rhizospheric bacteria were isolated from California field grown rice plants (M-104), eleven of which were taxonomically identified by16S rRNA gene sequencing and fatty acid methyl ester (FAME) analysis. Bacterial isolates were tested for biocontrol activity against the devastating foliar rice fungal pathogen, M. oryzae pathovar 70–15. In vitro, a Pseudomonas isolate, EA105, displayed antibiosis through reducing appressoria formation by nearly 90% as well as directly inhibiting fungal growth by 76%. Although hydrogen cyanide (HCN) is a volatile commonly produced by biocontrol pseudomonads, the activity of EA105 seems to be independent of its HCN production. During in planta experiments, EA105 reduced the number of blast lesions formed by 33% and Pantoea agglomerans isolate, EA106 by 46%. Our data also show both EA105 and EA106 trigger jasmonic acid (JA) and ethylene (ET) dependent induced systemic resistance (ISR) response in rice. Conclusions Out of 11 bacteria isolated from rice soil, pseudomonad EA105 most effectively inhibited the growth and appressoria formation of M. oryzae through a mechanism that is independent of cyanide production. In addition to direct antagonism, EA105 also appears to trigger ISR in rice plants through a mechanism that is dependent on JA and ET signaling, ultimately resulting in fewer blast lesions. The application of native bacteria as biocontrol agents in combination with current disease protection strategies could aid in global food security. PMID:24884531

2014-01-01

296

Allelopathy in Forested Ecosystems  

Microsoft Academic Search

In the context of forestry, the concept of allelopathy has recently been expanded from a plant to plant interference phenomenon\\u000a to an ecosystem-level phenomenon that is influenced by ecosystem disturbance. This chapter reviews the latest development\\u000a in our understanding of forest allelopathy and the ways in which this new knowledge can be used in sustainable forest management.\\u000a Allelopathic effects of

Azim U. Mallik

297

Limiting Factors in Ecosystems  

NSDL National Science Digital Library

This unit, designed to span two class periods, helps students understand that physical factors, particularly temperature and precipitation, limit the growth of plant ecosystems. The activity begins with a discussion in which students develop their own ideas about the role of temperature, precipitation, and environment on plant growth. They will then examine X-Y graphs of vegetation growth, temperature, and precipitation versus month for four diverse ecosystems to determine which climatic factor is limiting growth. A worksheet and scoring rubric are provided.

298

Agglomeration characteristics of silica sand-rice husk ash mixtures at elevated temperatures  

SciTech Connect

Rice husk, a major by-product of the rice milling process, can be a significant energy resource in rice producing countries because of its high energy content. Fluidized bed gasifiers have been proposed for the recovery of energy from rice husk. The major advantage of fluidized bed gasifiers over fixed bed gasifiers is the high mass and heat transfer capability due to very high percentage of inert bed material such as silica sand. In addition, the vigorous mixing and agitation of solid particles in fluidized beds promote a uniform temperature distribution and a high conversion efficiency. However, attempts to utilize rice husk as a feed in fluidized bed gasifiers have been unsuccessful because of the high ash content of rice husk that may result in the agglomeration of inert bed materials at high temperatures. In this work, the effect of rice husk ash content on the agglomeration characteristics of silica sand was investigated at various temperatures using a muffle furnace. A light microscope, an environmental scanning electron microscope, and an energy dispersive X-ray analyzer were used to characterize the structural changes and elemental makeup of the samples. There was no indication of agglomeration below 850 C, but at temperatures of 850--1,000 C the silica sand loosely agglomerated in the presence of rice husk ash at all levels of ash content. The effect was more pronounced at 1,000 C. The chemical interaction of the SiO{sub 2} and the low melting temperature mineral oxides present in notably low concentrations in rice husk ash, appeared to be the mechanism resulting in the formation of the loose agglomerates.

Mansaray, K.G.; Ghaly, A.E. [Technical Univ. of Nova Scotia, Halifax (Canada). Agricultural Engineering Dept.

1998-08-01

299

A Historical Analysis of the Relationship Between Rice Production and PDSI Values in Sri Lanka  

NASA Astrophysics Data System (ADS)

As world population grows, there are ever increasing demands being placed on the food production systems throughout the world. Climate change is complicating these stressors even further through more frequent severe weather events. In the developing world, where there are fewer resources to mitigate the effects of climate change, the combination of these two factors can have drastic consequences. In Sri Lanka, farmers in major rice production areas of the country are already struggling to produce enough rice, a staple food of the local diet, and a severe wet or dry spell could be ruinous. Faced with a changing climate and a growing demand for rice, it is important to be able to anticipate how climatic changes will affect rice production. By examining how extreme wet and dry spells have historically affected rice production, decision makers may be better able to predict and prepare for potential food shortages. We conducted an analysis of historic temperature, precipitation, and rice production statistics in order to determine the effects of extreme wet and dry spells on rice production. We also created a timeline of major developments in Sri Lankan agriculture in order to compare effects on rice production due to changes in agricultural practices with meteorological changes. Historical temperature and precipitation data were used to calculate the Palmer Drought Severity Index (PDSI) for a number of stations distributed throughout the Mahaweli river basin. The basin, the largest in the country, contains three different climatic regions - dry, intermediate, and wet - that all receive different amounts of annual precipitation. The PDSI values were used to quantify drought and wetness during the Yala (April-September) and Maha (October-March) growing seasons. Analysis of historical PDSI values, agricultural advances, and rice production statistics shows great promise for anticipating and mitigating future food shortages.

Jacobi, J. H.; Hornberger, G. M.

2011-12-01

300

Urban Ecosystem Design Bedrich Benes  

E-print Network

Urban Ecosystem Design Bedrich Benes Michel Abdul Massih Philip Jarvis Purdue University Daniel G. Aliaga Carlos A. Vanegas a) b) c) Figure 1: This example demonstrates the need for urban ecosystems and the ecosystem is chaotic with no control. The image c) shows the managed urban ecosystem that has areas

Aliaga, Daniel G.

301

Ecosystem Management Strategies Katy Ransone  

E-print Network

Ecosystem Management Strategies Katy Ransone Biol 379- Dr. Dever 11/14/13 How we should manage as ecosystem management. The term 'ecosystem' is one that is somewhat loosely defined. In general, it includes all of the biotic (living) and abiotic (non-living) factors in a specified area. With the ecosystem

Dever, Jennifer A.

302

INTRODUCTION Coral reef ecosystems are among the most biologically diverse and  

E-print Network

1 INTRODUCTION Coral reef ecosystems are among the most biologically diverse and complex marine ecosystems worldwide. In addition to their biological and ecological importance, coral reefs support major to as zooxanthellae (Lesser, 2004). Because of global climate change and anthropogenic pressure, coral reef ecosystems

Paris-Sud XI, Université de

303

Analysis of Rice Act1 5[prime] Region Activity in Transgenic Rice Plants  

Microsoft Academic Search

The 5' region of the rice actin 1 gene (Actl) has been developed as an efficient regulator of foreign gene expression in transgenic rice plants. To determine the pattern and level of rice Actl 5' region activity, transgenic rice plants containing the Actl 5' region fused to a bacterial 8-glucuronidase (Gus) coding sequence were generated. Two independent clonal lines of

Wanggen Zhang; David McElroy; Ray WU

1991-01-01

304

Syrtis Major  

NASA Technical Reports Server (NTRS)

(Released 1 May 2002) The Science This image is from the region of Syrtis Major, which is dominated by a low-relief shield volcano. This area is believed to be an area of vigorous aeolian activity with strong winds in the east-west direction. The effects of these winds are observed as relatively bright streaks across the image, extending from topographic features such as craters. The brighter surface material probably indicates a smaller relative particle size in these areas, as finer particles have a higher albedo. The bright streaks seen off of craters are believed to have formed during dust storms. A raised crater rim can cause a reduction in the wind velocity directly behind it, which results in finer particles being preferentially deposited in this location. In the top half of the image, there is a large bright streak that crosses the entire image. There is no obvious topographic obstacle, therefore it is unclear whether it was formed in the same manner as described above. This image is located northwest of Nili Patera, a large caldera in Syrtis Major. Different flows from the caldera eruptions can be recognized as raised ridges, representing the edge of a flow lobe. The Story In the 17th century, Holland was in its Golden Age, a time of cultural greatness and immense political and economic influence in the world. In that time, lived a inquisitive person named Christian Huygens. As a boy, he loved to draw and to figure out problems in mathematics. As a man, he used these talents to make the first detailed drawings of the Martian surface - - only 50 years or so after Galileo first turned his telescope on Mars. Mars suddenly became something other than a small red dot in the sky. One of the drawings Huygens made was of a dark marking on the red planet's surface named Syrtis Major. Almost 350 years later, here we are with an orbiter that can show us this place in detail. Exploration lives! It's great we can study this area up close. In earlier periods of history, scientists were fascinated with Syrtis Major because this dark region varied so much through the seasons and years. Some people thought it might be a changing sea, and others thought it might be vegetation. Early spacecraft like Mariner and Viking revealed for the first time that the changes were caused by the wind blowing dust and sand across the surface. What we can see in this image is exactly that: evidence of a lot of wind action. Bright dust patches streak across this image, formed through wind interference from craters and other landforms. These wispy, bright streaks are spread on the surface by a vigorous, east-west wind that kicked up huge dust storms, scattering the fine particles of sand and dust in an almost etherial pattern. The bright streaks in the top part of the image might have formed in a slightly different way, because there is no landform standing in the wind's way. Beneath the bright surface dust are raised ridges that mark the edges of earlier lava flows from Nili Patera, a Martian 'caldera.' A caldera is a collapsed, bowl-shaped depression at the top of a volcano cone. Can you imagine how Christian Huygens would feel if he lived today and could see all of this knowledge unfold? Or how it would feel to be the first person to stand in this dark volcanic and cratered region, knowing how many discovers had paved the way to that moment? Yes, exploration lives!

2002-01-01

305

Rice University Electrical and Computer Engineering Neuroengineering  

E-print Network

Rice University Electrical and Computer Engineering Neuroengineering Learn more at ece Electrical and Computer Engineering Neuroengineering Faculty Learn more at ece.rice.edu Caleb Kemere, Assistant Professor, Electrical and Computer Engineering Research Interests: Building interfaces with memory

306

Texas Rice, Volume II, Number 2  

E-print Network

. Researchers at the Louisiana State University were able to successfully cross these abnormal rice plants with commercial varieties, creating new variet- ies that can be treated with imi or Newpath herbicide without killing the rice. In the past, a rice... that would lead to his discovery of an imi tolerant rice. And actually, he started out screening with other contact herbicides, as the imi chemistry had not yet been devel- oped. At first Croughan tried cellular level selection in petri dishes, whereby...

307

Energy flow in an arctic aquatic ecosystem  

SciTech Connect

This project has been using natural isotope abundances to trace major pathways of energy flow to consumers in Imnavait Creek and the tundra ecosystem of the R4D watershed with comparative work in the coastal tundra. We are processing samples collected at the R4D intensive site over the past three years and are comparing these data with similar samples collected from the coastal plain. Our approach is to determine if carbon is accumulating in upland and coastal tundra; to determine the role of eroded peat carbon in the aquatic ecosystem; and to determine the distribution of carbon and nitrogen isotopes in the tundra-pond ecosystem to establish the feasibility of using natural differences as tracers.

Schell, D.M.

1993-01-01

308

Energy flow in an arctic aquatic ecosystem  

SciTech Connect

This project has been using natural isotope abundances to trace major pathways of energy flow to consumers in Imnavait Creek and the tundra ecosystem of the R4D watershed with comparative work in the coastal tundra. We are processing samples collected at the R4D intensive site over the past three years and are comparing these data with similar samples collected from the coastal plain. Our approach is to determine if carbon is accumulating in upland and coastal tundra; to determine the role of eroded peat carbon in the aquatic ecosystem; and to determine the distribution of carbon and nitrogen isotopes in the tundra-pond ecosystem to establish the feasibility of using natural differences as tracers.

Schell, D.M.

1993-05-01

309

Speciation and monitoring test for inorganic arsenic in white rice flour.  

PubMed

A monitoring test for arsenic species in white rice flour was developed and applied to flours made from 20 samples of polished rice collected from locations all over Japan. The arsenic species in white rice flour made from five samples each of four types of rice were analyzed by HPLC-ICP-MS after a heat-assisted aqueous extraction. The total arsenic and major and minor element concentrations in the white rice flours were measured by ICP-MS and ICP-OES after microwave-assisted digestion. 91 ± 1% of the arsenic in the flours was extractable. Concentrations of arsenite [As(III)], arsenate [As(V)], and dimethylarsinic acid (DMAA) were closely positively correlated with the total arsenic concentrations. The total arsenic concentration in flours made from rice collected around Japan was 0.15 ± 0.07 mg kg(-1) (highest, 0.32 mg kg(-1)), which is very low. It was thus confirmed that the white rice flour samples collected in this experiment were not suffered from noticeable As contamination. PMID:22224477

Narukawa, Tomohiro; Hioki, Akiharu; Chiba, Koichi

2012-02-01

310

Bioaccessibility of arsenic in various types of rice in an in vitro gastrointestinal fluid system.  

PubMed

Rice can be a major contributor to dietary arsenic exposure because of the relatively high total arsenic concentration compared to other grains, especially for people whose main staple is rice. This study employed in vitro gastrointestinal fluid digestion to determine bioaccessible or gastrointestinal fluid extractable arsenic concentration in rice. Thirty-one rice samples, of which 60 % were grown in the United States, were purchased from food stores in New York City. Total arsenic concentrations in these samples ranged from 0.090 ± 0.004 to 0.85 ± 0.03 mg/kg with a mean value of 0.275 ± 0.161 mg/kg (n = 31). Rice samples with relatively high total arsenic (>0.20 mg/kg, n = 18) were treated by in vitro artificial gastrointestinal fluid digestion, and the extractable arsenic ranged from 53 % to 102 %. The bioaccessibility of arsenic in rice decreases in the general order of extra long grain, long grain, long grain parboiled, to brown rices. PMID:22251206

He, Yi; Pedigo, Christopher E; Lam, Billion; Cheng, Zhongqi; Zheng, Yan

2012-01-01

311

Grain-filling problem in 'super' rice.  

PubMed

Modern rice (Oryza sativa L.) cultivars, especially the newly bred 'super' rice, have numerous spikelets on a panicle with a large yield capacity. However, these cultivars often fail to achieve their high yield potential due to poor grain-filling of later-flowering inferior spikelets (in contrast to the earlier-flowering superior spikelets). Conventional thinking to explain the poor grain-filling is the consequence of carbon limitation. Recent studies, however, have shown that carbohydrate supply should not be the major problem because they have adequate sucrose at their initial grain-filling stage. The low activities of key enzymes in carbon metabolism may contribute to the poor grain-filling. Proper field practices, such as moderate soil drying during mid- and late grain-filling stages, could solve some problems in poor grain-filling. Further studies are needed by molecular approaches to investigate the signal transport, the hormonal action, the gene expressions, and the biochemical processes in inferior spikelets. PMID:19959608

Yang, Jianchang; Zhang, Jianhua

2010-01-01

312

Adaptation to flooding during emergence and seedling growth in rice and weeds, and implications for crop establishment  

PubMed Central

Background and aims Direct seeding of rice is being adopted in rainfed and irrigated lowland ecosystems because it reduces labour costs in addition to other benefits. However, early flooding due to uneven fields or rainfall slows down seed germination and hinders crop establishment. Conversely, early flooding helps suppress weeds and reduces the costs of manual weeding and/or dependence on herbicides; however, numerous weed species are adapted to lowlands and present challenges for the use of flooding to control weeds. Advancing knowledge on the mechanisms of tolerance of flooding during germination and early growth in rice and weeds could facilitate the development of improved rice varieties and effective weed management practices for direct-seeded rice. Principal results Rice genotypes with a greater ability to germinate and establish in flooded soils were identified, providing opportunities to develop varieties suitable for direct seeding in flooded soils. Tolerance of flooding in these genotypes was mostly attributed to traits associated with better ability to mobilize stored carbohydrates and anaerobic metabolism. Limited studies were undertaken in weeds associated with lowland rice systems. Remaining studies compared rice and weeds and related weed species such as Echinochloa crus-galli and E. colona or compared ecotypes of the same species of Cyperus rotundus adapted to either aerobic or flooded soils. Conclusions Tolerant weeds and rice genotypes mostly developed similar adaptive traits that allow them to establish in flooded fields, including the ability to germinate and elongate faster under hypoxia, mobilize stored starch reserves and generate energy through fermentation pathways. Remarkably, some weeds developed additional traits such as larger storage tubers that enlarge further in deeper flooded soils (C. rotundus). Unravelling the mechanisms involved in adaptation to flooding will help design management options that will allow tolerant rice genotypes to adequately establish in flooded soils while simultaneously suppressing weeds. PMID:22957137

Ismail, Abdelbagi M.; Johnson, David E.; Ella, Evangelina S.; Vergara, Georgina V.; Baltazar, Aurora M.

2012-01-01

313

Global climate changes and rice food security  

Microsoft Academic Search

Reducing hunger and poverty are the key United Nations Millenium Development Goals. This was the main reason for the UN declaration of the International Year of Rice 2004. In 2002, rice was the source of more than 500 calories per person per day for over 3 billion people (FAOSTAT). Furthermore, rice cultivation is the principal activity and source of income

N. V. Nguyen

314

Rice MBA Admissions Online Chat Transcript  

E-print Network

25061a: hi lmurrah(MBA Admissions Lolita): Hello Welcome to the Rice MBA Chat Session. We will begin in about 10 more minutes. lmurrah(MBA Admissions Lolita): Hello Welcome to the Rice MBA Chat Session. We Lolita): Hello Welcome to the Rice MBA Chat Session. We will begin in about 10 more minutes. lmurrah

315

Sequence and analysis of rice chromosome 4  

Microsoft Academic Search

Rice is the principal food for over half of the population of the world. With its genome size of 430 megabase pairs (Mb), the cultivated rice species Oryza sativa is a model plant for genome research. Here we report the sequence analysis of chromosome 4 of O. sativa, one of the first two rice chromosomes to be sequenced completely. The

Qi Feng; Yujun Zhang; Pei Hao; Shengyue Wang; Gang Fu; Yucheng Huang; Ying Li; Jingjie Zhu; Yilei Liu; Xin Hu; Peixin Jia; Yu Zhang; Qiang Zhao; Kai Ying; Shuliang Yu; Yesheng Tang; Qijun Weng; Lei Zhang; Ying Lu; Jie Mu; Yiqi Lu; Lei S. Zhang; Zhen Yu; Danlin Fan; Xiaohui Liu; Tingting Lu; Yongrui Wu; Tongguo Sun; Haiyan Lei; Tao Li; Hao Hu; Jianping Guan; Mei Wu; Runquan Zhang; Bo Zhou; Zehua Chen; Ling Chen; Zhaoqing Jin; Rong Wang; Haifeng Yin; Zhen Cai; Shuangxi Ren; Gang Lv; Wenyi Gu; Genfeng Zhu; Yuefeng Tu; Jia Jia; Yi Zhang; Jie Chen; Hui Kang; Xiaoyun Chen; Chunyan Shao; Yun Sun; Qiuping Hu; Xianglin Zhang; Wei Zhang; Lijun Wang; Chunwei Ding; Haihui Sheng; Jingli Gu; Shuting Chen; Lin Ni; Fenghua Zhu; Wei Chen; Lefu Lan; Ying Lai; Zhukuan Cheng; Minghong Gu; Jiming Jiang; Jiayang Li; Guofan Hong; Yongbiao Xue; Bin Han

2002-01-01

316

LASER SAFETY MANUAL 2012 RICE UNIVERSITY 1  

E-print Network

LASER SAFETY MANUAL 2012 RICE UNIVERSITY 1 Rice University Laser Safety Manual Environmental Health and Safety MS 123 P.O. Box 1892 Houston, TX 77251-1892 December 2012 #12;LASER SAFETY MANUAL 2012 RICE, and general procedures to aid those individuals working in the laser laboratory environment. It is intended

Natelson, Douglas

317

RADIATION SAFETY MANUAL 2012 RICE UNIVERSITY 1  

E-print Network

RADIATION SAFETY MANUAL 2012 RICE UNIVERSITY 1 Rice University Radiation Safety Manual Environmental Health and Safety MS 123 P.O. Box 1892 Houston, TX 77251-1892 February 2013 #12;RADIATION SAFETY MANUAL 2012 RICE UNIVERSITY 2 INTRODUCTION The goal of the Radiation Safety Manual is to assist lab

Natelson, Douglas

318

Red yeast rice: a new hypolipidemic drug  

Microsoft Academic Search

Red yeast rice is a source of fermented pigment with possible bioactive effect. Evidence shows that fermented red yeast rice lowers cholesterol levels moderately compared to other statin drugs, but with the added advantage of causing less adverse effects. A review of the body of evidence surrounding the properties of red yeast rice underscores its potential as a new alternative

Mélanie Journoud; Peter J. H Jones

2004-01-01

319

Enzymatic hydrolysis of pretreated rice straw  

Microsoft Academic Search

California rice straw is being evaluated as a feedstock for production of power and fuel. This paper examines the initial steps in the process: pretreatment of rice straw and enzymatic hydrolysis of the polysaccharides in the pretreated material to soluble sugars. Rice straw was subjected to three distinct pretreatment procedures: acid-catalyzed steam explosion (Swan Biomass Company), acid hydrolysis (U.S. DOE

E. Yu. Vlasenko; H. Ding; J. M. Labavitch; S. P. Shoemaker

1997-01-01

320

Satellite remote sensing of wild rice  

Microsoft Academic Search

Wild rice (Zizania aquatica) is a primary staple for Native Americans in the northern United States and there is a strong need to timely map and monitor its production on American Indian Reservations. This paper describes a methodology for the detection and classification of wild rice using satellite remote sensing. Landsat-7 data were used to map and estimate wild rice

R. C. Frohn

2001-01-01

321

Decomposition of rice residue in tropical soils  

Microsoft Academic Search

Nitrogen uptake by rice plants from rice straw incorporated, fertilizer (ammonium sulfate), and soil was investigated using N as a tracer in pot experiments conducted in the greenhouse of the International Rice Research Institute in the Philippines. The nitrogen from fertilizer was rapidly absorbed in an early growth stage. The nitrogen from straw was absorbed in an early growth stage

Tadakatsu Yoneyama; Tomio Yoshida

1977-01-01

322

Decomposition of rice residue in tropical soils  

Microsoft Academic Search

The decomposition processes of intact rice residue (leaf blades) in Maahas soil of the Philippines were investigated by incubation experiments at 30°C. The experiments dealt with nitrogen immobilization by rice residue under lowland and upland conditions. Rice residue which is low in nitrogen. absorbed nitrogen from the soil and from the added fertilizer (ammonium sulfate) during its decomposition under both

Tadakatsu Yoneyama; Tomio Yoshida

1977-01-01

323

Revised 7/10 1 RICE UNIVERSITY  

E-print Network

that opportunities or events may come up that cause you to leave Rice University to pursue other career or personal: _____________________ * Medical benefits - Your Rice medical benefits will end on: __________________________ * Vesting in the 401, and Benefits to discuss and enroll in retiree health benefits, if desired. ADDITIONAL RESOURCES: * Rice Human

324

Efficacy of Aquatain, a Monomolecular Film, for the Control of Malaria Vectors in Rice Paddies  

PubMed Central

Background Rice paddies harbour a large variety of organisms including larvae of malaria mosquitoes. These paddies are challenging for mosquito control because their large size, slurry and vegetation make it difficult to effectively apply a control agent. Aquatain, a monomolecular surface film, can be considered a suitable mosquito control agent for such breeding habitats due to its physical properties. The properties allow Aquatain to self-spread over a water surface and affect multiple stages of the mosquito life cycle. Methodology/Principal Findings A trial based on a pre-test/post-test control group design evaluated the potential of Aquatain as a mosquito control agent at Ahero rice irrigation scheme in Kenya. After Aquatain application at a dose of 2 ml/m2 on rice paddies, early stage anopheline larvae were reduced by 36%, and late stage anopheline larvae by 16%. However, even at a lower dose of 1 ml/m2 there was a 93.2% reduction in emergence of anopheline adults and 69.5% reduction in emergence of culicine adults. No pupation was observed in treated buckets that were part of a field bio-assay carried out parallel to the trial. Aquatain application saved nearly 1.7 L of water in six days from a water surface of 0.2 m2 under field conditions. Aquatain had no negative effect on rice plants as well as on a variety of non-target organisms, except backswimmers. Conclusions/Significance We demonstrated that Aquatain is an effective agent for the control of anopheline and culicine mosquitoes in irrigated rice paddies. The agent reduced densities of aquatic larval stages and, more importantly, strongly impacted the emergence of adult mosquitoes. Aquatain also reduced water loss due to evaporation. No negative impacts were found on either abundance of non-target organisms, or growth and development of rice plants. Aquatain, therefore, appears a suitable mosquito control tool for use in rice agro-ecosystems. PMID:21738774

Bukhari, Tullu; Takken, Willem; Githeko, Andrew K.; Koenraadt, Constantianus J. M.

2011-01-01

325

Measuring the Human Footprint on Ecosystem Function  

NASA Astrophysics Data System (ADS)

Major questions for the biogeosciences concern the consequences of human transformation of landscapes for biogeochemical cycling and other ecosystem functions. While it is clear that the footprint of humans extends to almost all corners of the world, there is no single measure of the anthropogenic effect on ecosystems. Unlike the "Keeling curve" representing anthropogenic carbon dioxide emissions in a single atmospheric measurement, the spatial and temporal heterogeneity of ecosystems and the patchy nature of human activities on the landscape make such a measurement impossible. Here we present two approaches for assessing the consequences of human modification of the landscape on ecosystem processes: the effects of past and future land use change on net primary production at the global scale and analysis of satellite observations over the past 18 years to quantify the carbon dioxide emissions from tropical land use change. Key issues for quantifying human influences on ecosystem function include accounting for natural variability on a variety of time scales and incorporating spatial heterogeneity in landscape-level analysis.

DeFries, R. S.; DeFries, R. S.

2001-12-01

326

Methane production in rice soil is inhibited by cyanobacteria.  

PubMed

The present study was aimed at understanding the role of cyanobacteria and Azolla in methane production and oxidation in laboratory simulation experiments using soil samples from rice fields. All the seven cyanobacterial strains tested effected a significant decrease in the headspace concentration of methane in flooded soil, incubated under light. Synechocystis sp. was the most effective in retarding methane concentration by 10-20 fold over that in controls without cyanobacteria. The decrease in the headspace concentration of methane was negligible in nonsterile soil samples, inoculated with Synechocystis sp. and then incubated under dark. Moist soil cores (0-5 cm depth), collected from rice fields that had been treated with urea in combination with a cyanobacterial mixture, Azolla microphylla, or cyanobacterial mixture plus A. microphylla, effected distinctly more rapid decrease in the headspace concentration of methane added at 200 microl(-1) than did the soil cores from plots treated with urea alone (30, 60, 90 and 120 kg N ha(-1)), irrespective of the rate of chemical nitrogen applied to rice fields. Besides, soil cores from plots treated with urea alone at 60, 90 and 120 kg N ha(-1) oxidised methane more rapidly than did the core samples from plots treated with urea alone at 30kg N ha(-1). Cyanobacteria and A. microphylla, applied to flood water, appear to play a major role in mitigation of methane emission from rice fields-through enhanced methane oxidation. PMID:11911608

Prasanna, Radha; Kumar, Vinod; Kumar, Sushil; Yadav, Ashok Kumar; Tripathi, Upasana; Singh, Atul Kumar; Jain, M C; Gupta, Prabhat; Singh, P K; Sethunathan, N

2002-01-01

327

Identification and quantification of anthocyanin pigments in colored rice  

PubMed Central

Anthocyanin pigments from varieties of black, red and wild rice were identified and quantified to evaluate their potential as nutritional function, natural colorants or functional food ingredients. Anthocyanin extraction was conducted with acidified methanol with 0.1M HCl (85:15, v/v) and identification of anthocyanin, aglycone and sugar moieties was conducted by comparison with purified standards by HPLC, Ultraviolet-Visible absorption spectrophotometer and paper chromatography. Black and wild rice showed three different types of pigments by HPLC whereas red rice variety did not show any anthocyanins. Out of three pigments detected, one (peak 2) was characterized as cyanidin-3-glucoside (C3G) by comparison of spectroscopic and chromatographic properties with an authentic standard, and another (peak 3) was tentatively identified as cyanidin-fructoside on the basis of spectroscopic properties with ?max of aglycone in 1% HCl methanol at 537 nm, electrospray ionization mass spectra with major ions at 449 and 287 m/z and chromatographic properties. But another pigment (peak 1) has not been characterized. The most abundant anthocyanin in black and wild rice was C3G. PMID:20126365

Kim, Min-Kyoung; Kim, Han-ah; Koh, Kwangoh; Lee, Young Sang; Kim, Yong Ho

2008-01-01

328

Effect of rice cultivars on root-associated methanotrophic communities  

NASA Astrophysics Data System (ADS)

Rice agriculture represents a major source of the greenhouse gas methane. However, a large amount of methane is oxidized by methanotrophic bacteria before being released to the atmosphere. Methanotrophs are characterized by their unique ability to use methane as sole source for carbon and energy. They are located at oxic-anoxic interfaces where methane and oxygen are present, such as the rhizosphere. Although they have been studied extensively in the past, only little is known about natural or anthropogenic factors influencing their large diversity. In this study, we investigated the effect of 20 different rice cultivars on methanotrophic communities associated with the roots of rice plants. The pmoA gene encoding a subunit of the particulate methane monooxygenase (catalyzing the first step of methane oxidation) was used as a functional and phylogenetic marker and analyzed using two different fingerprinting methods. The well established terminal restriction fragment length polymorphism (T-RFLP) analysis was compared to results obtained using a diagnostic pmoA microarray. Both methods indicated that type Ib (Methylococcus/Methylocaldum) and type II (Methylosinus/Methylocystis) were the predominat methanotrophs located on rice roots. Interestingly, analysis of pmoA transcripts suggested Methylobacter/Methylomonas (type Ia) to present the actively methane oxidizing population in this environment.

Lüke, C.; Frenzel, P.

2009-04-01

329

Ecological, Economic and Policy Alternatives for Texas Rice Agriculture  

E-print Network

to decline in Texas within this new policy climate, barring significant Institute for Science, Technology and Public Policy ii executive summary changes in markets, production methods, or policy. Indeed, our survey shows that a majority of rice producers... of the problem. However, the formation of farm policy is also influenced by more than the current understanding of the problem. It is also subject to U.S. and foreign agreements as well as world market activity, political climate, the strength of special interest...

Wui, Yong-Suhk; Tierce, Kelly; Nicholson, Jill; Mizell, Kelly; Krohn, Michelle R.; Kennedy, Elizabeth; Henry, April; Harris, Jeanine; Cowman, Deborah F.; Torres -Conkey, April Ann; Canzoneri, Nicole; Franklin, James C.; Woodward, Richard T.; Vedlitz, Arnold; Slack, R. Douglas; Lacher, Thomas E.; Alston, Letitia T.

2000-09-25

330

Sea ice ecosystems.  

PubMed

Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters. PMID:24015900

Arrigo, Kevin R

2014-01-01

331

Herbivore- and elicitor-induced resistance in rice to the rice water weevil (Lissorhoptrus oryzophilus Kuschel) in the laboratory and field.  

PubMed

Feeding by herbivores can change plants in ways that make them more resistant to subsequent herbivory. Such induced responses are better-studied in a number of model dicots than in rice and other cereals. In a series of greenhouse and field experiments, we assessed the effects of prior herbivory by the fall armyworm, Spodoptera frugiperda (J.E. Smith) and of exogenous applications of jasmonic acid (JA) on the resistance of rice plants to the rice water weevil, Lissorhoptrus oryzophilus (Kuschel), the major pest of rice in the United States. Prior feeding by S. frugiperda and treatment of plants with exogenous JA resulted in increases in the resistance of plants to the weevil. Increases in resistance were manifested as reduced numbers of eggs and first-instars associated with armyworm-injured or JA-treated plants relative to control plants. In field experiments, there was a transient but significant reduction in the number of immature L. oryzophilus on JA-treated plants relative to untreated plants. To our knowledge, this is the first example of direct induced resistance in rice demonstrated in small-plot field experiments. We discuss the potential for the use of elicitor induced resistance in rice. PMID:20151182

Hamm, Jason C; Stout, Michael J; Riggio, Rita M

2010-02-01

332

Phosphate starvation signaling in rice.  

PubMed

Phosphorus is one of the most essential and limiting macronutrients for plants. Phosphate (Pi) deficiency could affect crop productivity seriously in agriculture. How to cope with this problem? Unveiling the molecular mechanism behind the Pi starvation responses of plants will be helpful to solve this issue. Rice is one of the most important crops, which feeds over one-third of the people in the world. In this review, we summarize the recent progress on Pi starvation signaling in rice with the intention to provide a further insight into the molecular mechanism of Pi starvation responses in rice and to give a new research direction to design transgenic plants with high Pi efficiency. PMID:21617375

Hu, Bin; Chu, Chengcai

2011-07-01

333

Biogeochemical Processes in Microbial Ecosystems  

NASA Technical Reports Server (NTRS)

The hierarchical organization of microbial ecosystems determines process rates that shape Earth's environment, create the biomarker sedimentary and atmospheric signatures of life and define the stage upon which major evolutionary events occurred. In order to understand how microorganisms have shaped the global environment of Earth and potentially, other worlds, we must develop an experimental paradigm that links biogeochemical processes with ever-changing temporal and spatial distributions of microbial population, and their metabolic properties. Photosynthetic microbial mats offer an opportunity to define holistic functionality at the millimeter scale. At the same time, their Biogeochemistry contributes to environmental processes on a planetary scale. These mats are possibly direct descendents of the most ancient biological communities; communities in which oxygenic photosynthesis might have been invented. Mats provide one of the best natural systems to study how microbial populations associate to control dynamic biogeochemical gradients. These are self-sustaining, complete ecosystems in which light energy absorbed over a diel (24 hour) cycle drives the synthesis of spatially-organized, diverse biomass. Tightly-coupled microorganisms in the mat have specialized metabolisms that catalyze transformations of carbon, nitrogen. sulfur, and a host of other elements.

DesMarais, David J.; DeVincenzi, Donald L. (Technical Monitor)

2001-01-01

334

Stability and retention of micronutrients in fortified rice prepared using different cooking methods.  

PubMed

Fortified rice holds great potential for bringing essential micronutrients to a large part of the world population. However, it is unknown whether differences in cooking methods or in production of rice premix affect the final amount of micronutrient consumed. This paper presents a study that quantified the losses of five different micronutrients (vitamin A, iron, zinc, folic acid, and vitamin B12) in fortified rice that was produced using three different techniques (hot extrusion, cold extrusion, and coating) during cooking and five different cooking methods (absorption method with or without soaking, washing before cooking, cooking in excess water, and frying rice before cooking). Fortified rice premix from six different producers (two for each technique) was mixed with normal rice in a 1:100 ratio. Each sample was prepared in triplicate, using the five different cooking methods, and retention of iron, zinc, vitamin A, vitamin B12, and folic acid was determined. It was found that the overall retention of iron, zinc, vitamin B12, and folic acid was between 75% and 100% and was unaffected by cooking method, while the retention of vitamin A was significantly affected by cooking method, with retention ranging from 0% (excess water) to 80% (soaking), depending on the cooking method and producer of the rice premix. No systematic differences between the different production methods were observed. We conclude that different cooking methods of rice as used in different regions of the world do not lead to a major loss of most micronutrients, with the exception of vitamin A. The factors involved in protecting vitamin A against losses during cooking need to be identified. All production techniques of rice premix yielded similar results, showing that coating is not inferior to extrusion techniques. Standard overages (50%) for vitamin B12 and folic acid are too high. PMID:25134849

Wieringa, Frank T; Laillou, Arnaud; Guyondet, Christophe; Jallier, Vincent; Moench-Pfanner, Regina; Berger, Jacques

2014-09-01

335

Iron Biofortification of Myanmar Rice  

PubMed Central

Iron (Fe) deficiency elevates human mortality rates, especially in developing countries. In Myanmar, the prevalence of Fe-deficient anemia in children and pregnant women are 75 and 71%, respectively. Myanmar people have one of the highest per capita rice consumption rates globally. Consequently, production of Fe-biofortified rice would likely contribute to solving the Fe-deficiency problem in this human population. To produce Fe-biofortified Myanmar rice by transgenic methods, we first analyzed callus induction and regeneration efficiencies in 15 varieties that are presently popular because of their high-yields or high-qualities. Callus formation and regeneration efficiency in each variety was strongly influenced by types of culture media containing a range of 2,4-dichlorophenoxyacetic acid concentrations. The Paw San Yin variety, which has a high-Fe content in polished seeds, performed well in callus induction and regeneration trials. Thus, we transformed this variety using a gene expression cassette that enhanced Fe transport within rice plants through overexpression of the nicotianamine synthase gene HvNAS1, Fe flow to the endosperm through the Fe(II)-nicotianamine transporter gene OsYSL2, and Fe accumulation in endosperm by the Fe storage protein gene SoyferH2. A line with a transgene insertion was successfully obtained. Enhanced expressions of the introduced genes OsYSL2, HvNAS1, and SoyferH2 occurred in immature T2 seeds. The transformants accumulated 3.4-fold higher Fe concentrations, and also 1.3-fold higher zinc concentrations in T2 polished seeds compared to levels in non-transgenic rice. This Fe-biofortified rice has the potential to reduce Fe-deficiency anemia in millions of Myanmar people without changing food habits and without introducing additional costs. PMID:23750162

Aung, May Sann; Masuda, Hiroshi; Kobayashi, Takanori; Nakanishi, Hiromi; Yamakawa, Takashi; Nishizawa, Naoko K.

2013-01-01

336

Mapping QTLs for traits related to salinity tolerance at seedling stage of rice (Oryza sativa L.): an agrigenomics study of an Iranian rice population.  

PubMed

Rice (Oryza sativa L.) is one of the most important food crops in the world, especially in Asian countries, and salinity is a major constraint to the sustainability and expansion of rice cultivation. Genetically improving salt tolerance of rice is a highly important objective of rice breeding programs. Traits such as salt tolerance are quantitatively inherited. Hence, mapping quantitative trait loci (QTL) with molecular markers can be very helpful to plant breeders in the field of agricultural genomics (AgriGenomics). In this investigation, QTL analysis of physiological traits related to salt tolerance was carried out using F2:4 population of rice derived from a cross between a salt-tolerant variety, Gharib (indica), and a salt-sensitive variety, Sepidroud (indica). A linkage map based on 148 F2 individuals was constructed with 131 SSR markers and 105 AFLP markers, covering 2475.7 cM of rice genome with an average distance of 10.48?cM between flanking markers. A total of 41 QTLs for twelve physiological traits under salinity stress were detected distributed on all rice chromosomes, some of them being reported for the first time. Also, overlapping of QTLs related to salt tolerance were observed in this study. Some of the identified QTLs on specific chromosomal regions explaining high phenotypic variance could be used for marker-assisted selection (MAS) programs. New QTLs retrieved in this study play an important role in growth of rice at seedling stage in an Iranian local population under high salinity conditions. PMID:23638881

Ghomi, Khadijeh; Rabiei, Babak; Sabouri, Hossein; Sabouri, Atefeh

2013-05-01

337

Anti-complement activity of essential oils from red and black rice bran.  

PubMed

The volatile essential oils from red and black rice bran were obtained by hydrodistillation using a clevenger-type apparatus, and the components of that oil were analyzed by capillary gas chromatography-mass spectroscopy (GC-MS). The present study involved characterizing the chemical compositions, their amounts and the anti-complement activities of red and black rice bran. The red rice bran essential oils yield was 0.031%, and GC-MS analysis revealed that its major constituents were (E)-?-ocimene (3.12%), nonanal (11.32%), (2E, 4E)-decadienal (2.54%), myristic acid (41.32%), geranyactone (2.41%) and methyl oleate (2.46%). The black rice bran essential oils yield was 0.053%, and GC-MS analysis revealed that its major constituents were nonanal (8.31%), acrylic acid (3.21%), 2-hydroxy-6-methylbenzaldehyde (2.81%), pelargonic acid (4.21%) and myrisitc acid (28.07%). The essential oils showed inhibitory activity against complement system with 50% inhibitory concentrations (IC(50)) values of 246 ppm (red rice bran) and 193 ppm (black rice bran). Also, myristic acid, nonanal, (E)-?-ocimene and pelargonic acid were tested against complement system. Pelargonic acid was shown to moderate activity (50% inhibitory concentration = 132 ?M). PMID:20673187

Chung, Ill-Min; Yeo, Min-A; Kim, Sun-Jin; Moon, Hyung-In

2011-05-01

338

Suppression of rice methane emission by sulfate deposition in simulated acid rain  

NASA Astrophysics Data System (ADS)

Sulfate in acid rain is known to suppress methane (CH4) emissions from natural freshwater wetlands. Here we examine the possibility that CH4 emissions from rice agriculture may be similarly affected by acid rain, a major and increasing pollution problem in Asia. Our findings suggest that acid rain rates of SO42- deposition may help to reduce CH4 emissions from rice agriculture. Emissions from rice plants treated with simulated acid rain at levels of SO42- consistent with the range of deposition in Asia were reduced by 24% during the grain filling and ripening stage of the rice season which accounts for 50% of the overall CH4 that is normally emitted in a rice season. A single application of SO42- at a comparable level reduced CH4 emission by 43%. We hypothesize that the reduction in CH4 emission may be due to a combination of effects. The first mechanism is that the low rates of SO42- may be sufficient to boost yields of rice and, in so doing, may cause a reduction in root exudates to the rhizosphere, a key substrate source for methanogenesis. Decreasing a major substrate source for methanogens is also likely to intensify competition with sulfate-reducing microorganisms for whom prior SO42- limitation had been lifted by the simulated acid rain S deposition.

Gauci, Vincent; Dise, Nancy B.; Howell, Graham; Jenkins, Meaghan E.

2008-09-01

339

Grays Lake Ecosystem  

NSDL National Science Digital Library

This case study looks at the marsh ecosystem of Grays Lake in southeast Idaho, and is hosted by the Northern Prairie Wildlife Research Center (NPWRC). Grays Lake has been the focus of numerous research studies to understand factors affecting breeding water birds, habitat management practices, populations, and geological factors. This report gives general information about the Grays Lake ecosystem, including climate, habitats, plant communities, wildlife, water, and geology. More specific details are given through flora and fauna lists, historical and cultural overviews, details about the Grays Lake National Wildlife Refuge, and research information on management of wetlands.

340

Energy flow in an arctic aquatic ecosystem  

SciTech Connect

Natural isotope abundances to trace major pathways of energy flow to consumers in Imnavait Creek and the tundra ecosystem of the R4D watershed with comparative work in the coastal tundra. Our overall goals are to a determine if carbon is accumulating in upland and coastal tundra; determine the role of eroded peat carbon in the aquatic ecosystem; and to determine the distribution of carbon and nitrogen isotopes in the tundra-pond ecosystem to establish the feasibility of using natural differences as tracers. Past work on fishes, birds, and the prey species of insects and aquatic crustaceans has shown that peat carbon is very important in the energy supply supporting the food webs over the course of the year. Obligate freshwater fishes from the coastal lakes and Colville River have been shown to contain up to 60 percent peat carbon at the end of the winter season. In contrast, migratory shorebirds and passerines contained much smaller radiocarbon abundances in summer, indicating a major shift to recent in situ primary production in pond and stream ecosystems in summer months. For the past two years, we have narrowed our focus to the processes supplying carbon to the beaded stream system at MS-117 and have concentrated on determining the transfer and accumulation rates of carbon in the watershed.

Schell, D.M.

1988-12-31

341

Energy flow in an arctic aquatic ecosystem  

SciTech Connect

Natural isotope abundances to trace major pathways of energy flow to consumers in Imnavait Creek and the tundra ecosystem of the R4D watershed with comparative work in the coastal tundra. Our overall goals are to a determine if carbon is accumulating in upland and coastal tundra; determine the role of eroded peat carbon in the aquatic ecosystem; and to determine the distribution of carbon and nitrogen isotopes in the tundra-pond ecosystem to establish the feasibility of using natural differences as tracers. Past work on fishes, birds, and the prey species of insects and aquatic crustaceans has shown that peat carbon is very important in the energy supply supporting the food webs over the course of the year. Obligate freshwater fishes from the coastal lakes and Colville River have been shown to contain up to 60 percent peat carbon at the end of the winter season. In contrast, migratory shorebirds and passerines contained much smaller radiocarbon abundances in summer, indicating a major shift to recent in situ primary production in pond and stream ecosystems in summer months. For the past two years, we have narrowed our focus to the processes supplying carbon to the beaded stream system at MS-117 and have concentrated on determining the transfer and accumulation rates of carbon in the watershed.

Schell, D.M.

1988-01-01

342

Fertilizers for Rice in Texas.  

E-print Network

was needed more than phosphoric acid. During the thirteen years of the experiment, the application of 100 pounds of sulphate of ammonia per acre made the largest average yield of rice, 2,353 pounds per acre, or 553 pounds per acre more than the yield... sources of nitrogen as sulphate of ammonia. The use of 150 pounds of 16 per cent superphosphate per acre increased the yield of rice 239 pounds per acre a year during the thirteen years of the experiment. The treat- ment of 150 pounds of superphosphate...

Reynolds, E. B. (Elbert Brunner); Wyche, R. H. (Robert Henry)

1929-01-01

343

Texas Rice, Highlights in Research  

E-print Network

focuses on measuring main and ratoon continued on next page L to R: Mike Jund, Research Associate, Dr. Fred Turner, Professor of Soil and Plant Nutrition, and Darrell Hagler, Technician II. Figure 1 Nitr ogen in Plant (lbs/A) Texas Rice Special Section.... Performance results from previous tests will be handed-out at field day. The four types of rice being evaluated are Semidwarf (Cocodrie, Cheniere, Jefferson and TX 9092); Taller than semidwarf (Cybonnet and Banks); Hybrid (XP723); and Herbicide resistant...

2004-01-01

344

Differentially Expressed Genes Distributed Over Chromosomes and Implicated in Certain Biological Processes for Site Insertion Genetically Modified Rice Kemingdao  

PubMed Central

Release of genetically modified (GM) plants has sparked off intensive debates worldwide partly because of concerns about potential adverse unintended effects of GM plants to the agro system and the safety of foods. In this study, with the aim of revealing the molecular basis for unintended effects of a single site insertion GM Kemingdao (KMD) rice transformed with a synthetic cry1Ab gene, and bridging unintended effects of KMD rice through clues of differentially expressed genes, comparative transcriptome analyses were performed for GM KMD rice and its parent rice of Xiushui11 (XS11). The results showed that 680 differentially expressed transcripts were identified from 30-day old seedlings of GM KMD rice. The absolute majority of these changed expression transcripts dispersed and located over all rice chromosomes, and existed physical distance on chromosome from the insertion site, while only two transcripts were found to be differentially expressed within the 21 genes located within 100 kb up and down-stream of the insertion site. Pathway and biology function analyses further revealed that differentially expressed transcripts of KMD rice were involved in certain biological processes, and mainly implicated in two types of pathways. One type was pathways implicated in plant stress/defense responses, which were considerably in coordination with the reported unintended effects of KMD rice, which were more susceptible to rice diseases compared to its parent rice XS11; the other type was pathways associated with amino acids metabolism. With this clue, new unintended effects for changes in amino acids synthesis of KMD rice leaves were successfully revealed. Such that an actual case was firstly provided for identification of unintended effects in GM plants by comparative transciptome analysis. PMID:22811617

Liu, Zhi; Li, Yunhe; Zhao, Jie; Chen, Xiuping; Jian, Guiliang; Peng, Yufa; Qi, Fangjun

2012-01-01

345

A rice-based soluble form of a murine TNF-specific llama variable domain of heavy-chain antibody suppresses collagen-induced arthritis in mice.  

PubMed

Tumor necrosis factor alpha (TNF) plays a pivotal role in chronic inflammatory diseases such as rheumatoid arthritis and Crohn's disease. Although anti-TNF antibody therapy is now commonly used to treat patients suffering from these inflammatory conditions, the cost of treatment continues to be a concern. Here, we developed a rice transgenic system for the production of a llama variable domain of a heavy-chain antibody fragment (VHH) specific for mouse TNF in rice seeds (MucoRice-mTNF-VHH). MucoRice-mTNF-VHH was produced at high levels in the rice seeds when we used our most recent transgene-overexpression system with RNA interference technology that suppresses the production of major rice endogenous storage proteins while enhancing the expression of the transgene-derived protein. Production levels of mTNF-VHH in rice seeds reached an average of 1.45% (w/w). Further, approximately 91% of mTNF-VHH was released easily when the powder form of MucoRice-mTNF-VHH was mixed with PBS. mTNF-VHH purified by means of single-step gel filtration from rice PBS extract showed high neutralizing activity in an in vitro mTNF cytotoxicity assay using WEHI164 cells. In addition, purified mTNF-VHH suppressed progression of collagen-induced arthritis in mice. These results show that this rice-expression system is useful for the production of neutralizing VHH antibody specific for mTNF. PMID:24548461

Abe, Michiyo; Yuki, Yoshikazu; Kurokawa, Shiho; Mejima, Mio; Kuroda, Masaharu; Park, Eun Jeong; Scheller, Jürgen; Nakanishi, Ushio; Kiyono, Hiroshi

2014-04-10

346

Predicting toxicity in aquatic ecosystems  

SciTech Connect

Ash leachates and other utility wastes that may enter lakes or streams contain mixtures of chemicals that include several kinds of toxicants. The toxic properties of these mixtures vary with the chemical form and concentration of their constituents. EPRI is developing a general toxicity model (GTM) to simulate environmental conditions in bodies of water where toxicants are present, and to predict the effects of toxicants on aquatic life-forms and ecosystems. To date, scientists have developed analytical methods to measure ambient concentrations of the major species of trace elements (selenium, arsenic, and mercury) and a model to describe the biogeochemical role of selenium. Recent studies of selenium cycling through the aquatic food web support GTM development.

Porcella, D. (Electric Power Research Inst., Palo Alto, CA (United States))

1992-03-01

347

Ecosystem approach to management I. "dynamic" ecosystem management v.  

E-print Network

parts of it, ecosystem structure and function is the focus of management Considers the effects = long term Ecosystem management Considers humans and all living components as one interacting system of the community #12;4 Sustainable management at an ecosystem level will only succeed when human welfare

Dever, Jennifer A.

348

New insights into the complex and coordinated transcriptional regulation networks underlying rice seed development through cDNA chip-based analysis  

Microsoft Academic Search

Transcription factors (TFs) are major, crucial factors for developmental control. To elucidate the effects of TFs on rice seed development, we generated a cDNA chip containing 325 rice cDNA clones, which are from flowering stage and encode known or putative TFs belonging to 12 different families, and used this chip for expression profiling at 8 continuous seed developmental stages. The

Ke Duan; Yong-Hai Luo; Da Luo; Zhi-Hong Xu; Hong-Wei Xue

2005-01-01

349

Rice growth, yield and water productivity responses to irrigation scheduling prior to the delayed application of continuous flooding in south-east Australia  

Microsoft Academic Search

The majority of rice grown in south-east Australia is continuously flooded for much of its growing season, but reduced irrigation water availability brought about by a combination of drought and environmental flow legislation has presented a need to maintain (or even increase) rice production with less irrigation water. Delaying the application of continuous flooding until prior to panicle initiation can

B. W. Dunn; D. S. Gaydon

2011-01-01

350

DECOMPOSITION IN FRESHWATER ECOSYSTEMS  

Microsoft Academic Search

This review examines the sources and composition of organic matter and the decomposition of particulate and dissolved organic matter (POM and DOM) in freshwater ecosystems. The main points to emerge from the review are listed below.1. Terrestrial plant material is an important source of allochthonous POM in lotlc systems.2. In lentic systems important autochthonous sources of DOM are the algae

R. D. Robarts

1986-01-01

351

The Global Ecosystem  

NSDL National Science Digital Library

This site contains 11 questions on the topic of ecosystems, which covers food chains and organism characteristics. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit an answer and are provided immediate verification.

Heaton, Timothy

352

TERRESTRIAL ECOSYSTEM SIMULATOR  

EPA Science Inventory

The Terrestrial Habitats Project at the Western Ecology Division (Corvallis, OR) is developing tools and databases to meet the needs of Program Office clients for assessing risks to wildlife and terrestrial ecosystems. Because habitat is a dynamic condition in real-world environm...

353

Resistance of cultivated rice varieties to Cnaphalocrocis medinalis (Lepidoptera: Pyralidae).  

PubMed

Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae) is a major pest in rice, Oryza sativa L. (Graminales: Poaceae), in Asia. The current study investigated the resistance of 17 rice varieties or lines to C. medinalis and behavioral responses of the insect to varieties of different corrected damage ratings (CDRs) and damaged leaves scales (DLSs). The results showed that most varieties (or lines) commonly cultured in rice production were susceptible (DLS 3 and 5) to damage caused by C. medinalis; Yangjing 9538, 91SP, and TN1 were the most susceptible (DLS 7 and 9). A significant positive correlation was observed between CDR and leaf width and chlorophyll content in rice leaves, whereas no significant correlations between resistance and plant height and leaf length were found. The number of eggs laid by C. medinalis adult females significantly increased with CDR. There was a significant difference in the number of eggs laid for varieties of different DLSs. The number laid on varieties of DLS 9 was 44.4, 134.5, and 466.7% greater than DLS 7, 5 and 3, respectively; the number laid on varieties of DLS 7 was 65.5% greater than DLS 5 and 300% greater than DLS 3; and the number laid on those of DLS 5 was 141.7% greater than DLS 3. Developmental duration (day) of larvae, the body length of fifth instar larvae and pupae weight also significantly increased with CDR. A significant difference of to excised leaves was also found among different DLSs with a higher proportion of both first and third instars settled on the leaves of high DLS. Dispersal experiments of larvae on excised leaves showed that the number of first instars that remained settled gradually increased with DLSs. These findings suggested that rice of higher DLS are more suitable for feeding and settling of larvae. PMID:20857724

Xu, Jie; Wang, Qi-Xiang; Wu, Jin-Cai

2010-08-01

354

Ecosystem Restoration Research at GWERD  

EPA Science Inventory

Ground Water and Ecosystems Restoration Division, Ada, OK Mission: Conduct research and technical assistance to provide the scientific basis to support the development of strategies and technologies to protect and restore ground water, surface water, and ecosystems impacted b...

355

Introduction Ecosystem management has been  

E-print Network

65(2) 1 Introduction Ecosystem management has been vigorously debated at many meetings, conferences, and workshops (Inter- agency Ecosystem Management Task Force, 1995; Malone, 1995; Stanley, 1995; Christensen et

356

Rice University Electrical and Computer Engineering Computer Engineering  

E-print Network

Rice University Electrical and Computer Engineering Computer Engineering Learn more at ece.rice.edu The Computer Engineering group at Rice University has a long track record of innovative research in physical sub-8psec impulses. Developed at Rice. #12;Rice University Electrical and Computer Engineering

357

Novel Phr1 mutations and the evolution of phenol reaction variation in US weedy rice (Oryza sativa)  

PubMed Central

Summary Red rice, a major agricultural weed, is phenotypically diverse and possesses traits that are similar to both wild and cultivated rice. The genetic resources available for rice make it possible to examine the molecular basis and evolution of traits characterizing this weed. Here, we assess the phenol reaction – a classical trait for distinguishing among cultivated rice varieties – in red rice at the phenotypic and molecular levels.We phenotyped more than 100 US weed samples for the phenol reaction and sequenced the underlying Phr1 locus in a subset of samples. Data were analyzed in combination with previously published Phr1 data for cultivated rice.Most weed accessions (96.3%) are positive for the phenol reaction, and samples with a negative response carry loss-of-function alleles that are rare or heretofore undocumented. One such allele may have evolved through mutational convergence of a 1-bp frameshift insertion. Haplotype sharing between red rice and US cultivars suggests occasional crop–weed hybridization.Our discovery of previously undocumented nonfunctional phr1 alleles suggests that there are likely to be other loss-of-function mutations segregating in Oryza sativa around the world. Red rice may provide a useful study system for understanding the adaptive significance of Phr1 variation in agricultural settings. PMID:19674331

Gross, Briana L.; Skare, Karl J.; Olsen, Kenneth M.

2010-01-01

358

LSCHL4 from Japonica Cultivar, Which Is Allelic to NAL1, Increases Yield of Indica Super Rice 93-11  

PubMed Central

The basic premise of high yield in rice is to improve leaf photosynthetic efficiency and coordinate the source–sink relationship in rice plants. Quantitative trait loci (QTLs) related to morphological traits and chlorophyll content of rice leaves were detected at the stages of heading to maturity, and a major QTL (qLSCHL4) related to flag leaf shape and chlorophyll content was detected at both stages in recombinant inbred lines constructed using the indica rice cultivar 93-11 and the japonica rice cultivar Nipponbare. Map-based cloning and expression analysis showed that LSCHL4 is allelic to NAL1, a gene previously reported in narrow leaf mutant of rice. Overexpression lines transformed with vector carrying LSCHL4 from Nipponbare and a near-isogenic line of 93-11 (NIL-9311) had significantly increased leaf chlorophyll content, enlarged flag leaf size, and improved panicle type. The average yield of NIL-9311 was 18.70% higher than that of 93-11. These results indicate that LSCHL4 had a pleiotropic function. Exploring and pyramiding more high-yield alleles resembling LSCHL4 for super rice breeding provides an effective way to achieve new breakthroughs in raising rice yield and generate new ideas for solving the problem of global food safety. PMID:24795339

Zhang, Guang-Heng; Li, Shu-Yu; Wang, Li; Ye, Wei-Jun; Zeng, Da-Li; Rao, Yu-Chun; Peng, You-Lin; Hu, Jiang; Yang, Yao-Long; Xu, Jie; Ren, De-Yong; Gao, Zhen-Yu; Zhu, Li; Dong, Guo-Jun; Hu, Xing-Ming; Yan, Mei-Xian; Guo, Long-Biao; Li, Chuan-You; Qian, Qian

2014-01-01

359

Investigating the impact of rice blast disease on the livelihood of the local farmers in greater Mwea region of Kenya.  

PubMed

Rice is the most important cereal crop in Kenya coming third after maize and wheat. It forms a very important diet for a majority of families in Kenya. The demand for rice in Kenya has seen a dramatic increase over the last few years while production has remained low. This is because rice production has been faced by serious constraints notably plant diseases of which the most devastating is rice blast. Rice blast is known to cause approximately 60% -100% yield losses. It is caused by an Ascomycete fungus called Magnaporthe Oryzae. The aim of this study was to investigate the impact of rice blast disease on the livelihood of the local farmers in Greater Mwea region and develop a rice blast disease distribution map using GIS approach. The study methodology employed a questionnaire survey which were subjected to sample population of households in the 7 sections with 70 blocks within Mwea region. The collected data was analysed using SAS Version 9.1. Descriptive statistics were used to summarize the household characteristics, the farm characteristics and the farmers' perceptions of rice blast disease. In the questionnaire, farmers' response on whether they had been affected by rice blast disease and the total production per acreage was used to develop an attribute table with GPS points. The GPS points were interpolated to create a geographical distribution map of rice blast disease. From the research findings almost all the farmers' had awareness and knowledge of rice blast disease, 98% of the farmers interviewed were aware of rice blast disease. Out of the 98% with knowledge and awareness 76% have been affected by the disease, while 24% have never been affected. Farmers attributed rice blast disease to a range of different causes, including excessive use of nitrogen fertilizer, water shortage, lack of proper drainage canal and due to climate change. Majority of the farmers interviewed (72%) did not engage themselves in any other socio-economic activity even after being affected by the rice blast disease. 15% opted to growing horticultural crops, 7% engaged in trading activities while 2% started livestock raring, wage earning and Boda boda business. PMID:23888278

Kihoro, Joseph; Bosco, Njoroge J; Murage, Hunja; Ateka, Elijah; Makihara, Daigo

2013-12-01

360

MENU NEW! CHICKEN RICE BOWL  

Microsoft Academic Search

We started offering a Rice Bowl bar in our high schools this fall and it got rave reviews from students and staff. So our elementary and middle school cafeteria supervisors asked if they could serve it too! We tested this popular entrée at Ramsey Junior High and Franklin Elementary School and asked kids what they thought. The con- sensus? A

Sloppy Joe; Chicken Patty Sandwich; Steak Fries

361

Agriculture Education. Soybeans and Rice.  

ERIC Educational Resources Information Center

This curriculum guide is designed for group instruction of secondary students enrolled in one or two semester-long courses in agricultural education. The guide presents units of study in the following areas: (1) soybeans, (2) rice, and (3) orientation. Each of the 17 units of instruction follows a typical format: terminal objective, specific…

Stuttgart Public Schools, AR.

362

Bruce N. Walker RICE UNIVERSITY  

E-print Network

Copyright Bruce N. Walker 2000 #12;RICE UNIVERSITY Magnitude Estimation of Conceptual Data OF THE REQUIREMENTS FOR THE DEGREE Doctor of Philosophy APPROVED, THESIS COMMITTEE: David M. Lane, Associate Professor like to acknowledge the contribution of my advisor, David M. Lane, who granted me the freedom

363

WEB FREE RICE Yuhei YAMAUCHI  

E-print Network

;12 4 Monogatari 10 Monogatari Conomi WEB Monogatari IC 2 TV TV #12;13 200 WEB FREE RICE 1 10 ? ? 2009):955-62. 5.Monti,M.M.,D.N.Osherson,M.J.Martinez,and L.M.Parsons.2007. "FunctionalNeuroanatomy of Deductive

Miyashita, Yasushi

364

Methane emission from rice paddies  

Microsoft Academic Search

Methane release rates from rice paddies have been measured in Andalusia, Spain, during almost a complete vegetation period in 1982 using the static box system. The release rates ranged between 2 and 14 mg\\/m2\\/h and exhibited a strong seasonal variation with low values during the tillering stage and shortly before harvest, while maximum values were observed at the end of

W. Seiler; A. Holzapfel-Pschorn; R. Conrad; D. Scharffe

1983-01-01

365

Huajian Gao James R. Rice  

E-print Network

Shear Stress Intensity Factors for a Planar Crack With Slightly Curved Front Recent work (Rice, 1985a elasticfull space. That work also indicated the relation of such calculations to a three-dimensional weight function theoryfor crack analysis and derived an expression for the distribution of the tensile mode stress

366

Epigenetic Inheritance in Rice Plants  

PubMed Central

Background and Aims Epigenetics is defined as mechanisms that regulate gene expression without base sequence alteration. One molecular basis is considered to be DNA cytosine methylation, which reversibly modifies DNA or chromatin structures. Although its correlation with epigenetic inheritance over generations has been circumstantially shown, evidence at the gene level has been limited. The present study aims to find genes whose methylation status directly correlates with inheritance of phenotypic changes. Methods DNA methylation in vivo was artificially reduced by treating rice (Oryza sativa ssp. japonica) seeds with 5-azadeoxycytidine, and the progeny were cultivated in the field for > 10 years. Genomic regions with changed methylation status were screened by the methylation-sensitive amplified polymorphysm (MSAP) method, and cytosine methylation was directly scanned by the bisulfite mapping method. Pathogen infection with Xanthomonas oryzae pv. oryzae, race PR2 was performed by the scissors-dip method on mature leaf blades. Key Results The majority of seedlings were lethal, but some survived to maturity. One line designated as Line-2 showed a clear marker phenotype of dwarfism, which was stably inherited by the progeny over nine generations. MSAP screening identified six fragments, among which two were further characterized by DNA blot hybridization and direct methylation mapping. One clone encoding a retrotransposon gag–pol polyprotein showed a complete erasure of 5-methylcytosines in Line-2, but neither translocation nor expression of this region was detectable. The other clone encoded an Xa21-like protein, Xa21G. In wild-type plants, all cytosines were methylated within the promoter region, whereas in Line-2, corresponding methylation was completely erased throughout generations. Expression of Xa21G was not detectable in wild type but was constitutive in Line-2. When infected with X. oryzae pv. oryzae, against which Xa21 confers resistance in a gene-for-gene manner, the progeny of Line-2 were apparently resistant while the wild type was highly susceptible without Xa21G expression. Conclusions These results indicated that demethylation was selective in Line-2, and that promoter demethylation abolished the constitutive silencing of Xa21G due to hypermethylation, resulting in acquisition of disease resistance. Both hypomethylation and resistant trait were stably inherited. This is a clear example of epigenetic inheritance, and supports the idea of Lamarckian inheritance which suggested acquired traits to be heritable. PMID:17576658

Akimoto, Keiko; Katakami, Hatsue; Kim, Hyun-Jung; Ogawa, Emiko; Sano, Cecile M.; Wada, Yuko; Sano, Hiroshi

2007-01-01

367

Teaching about Ecosystems. ERIC Digest.  

ERIC Educational Resources Information Center

Ecosystems are available to educators as interactive units and as such the National Science Education Standards (NSES) and the Excellence in Environmental Education: Guidelines for Learning (EEE) put considerable emphasis on ecosystems. This ERIC Digest describes the NSES and EEE guidelines for grades 5-8 and 9-12 to provide a basic ecosystem…

Haury, David L.

368

Investigating Ecosystems in a Biobottle  

ERIC Educational Resources Information Center

Biobottles are miniature ecosystems made from 2-liter plastic soda bottles. They allow students to explore how organisms in an ecosystem are connected to each other, examine how biotic and abiotic factors influence plant and animal growth and development, and discover how important biodiversity is to an ecosystem. This activity was inspired by an…

Breene, Arnica; Gilewski, Donna

2008-01-01

369

Evolution of Continental Aquatic Ecosystems  

Microsoft Academic Search

Ecosystem evolution still remains the least under- stood part of evolutionary theory. Discussions of eco- system evolution almost inevitably digress to biotic components, often to a single group of organisms. Cer- tainly, biotic components evolve with ecosystems, but the focus should not be displaced from ecosystem char- acters as such, the trophic and, more generally speak- ing, the information links

A. G. Ponomarenko

1996-01-01

370

Ecosystem services and water economics  

E-print Network

Ecosystem services and water economics Florida Agricultural Commodity & Policy Outlook Conference, Food & Resource Economics Department, University of Florida/IFAS · Part II. Markets for Ecosystem preferences o Technological changes o Market competition o Recent: · Water availability · Ecosystem service

Hill, Jeffrey E.

371

Ecosystem Task Force Meeting Minutes  

E-print Network

Ecosystem Task Force Meeting Minutes Date: April 28, 2011 Title of Meeting: Monthly Meeting. A focus on planning helps ground the Task Force because of the complexity of ecosystems. UNH-862-0785 sustainability.info@unh.edu http://www.sustainableunh.unh.edu/ #12;3.1. Ecosystem work has no defined parameters

New Hampshire, University of

372

Ecosystem Services and Environmental Benefits  

E-print Network

Ecosystem Services and Environmental Benefits of the UC San Diego Campus Forest 10 February 2009 #12;2 #12;3 Ecosystem Services and Environmental Benefits of the UC San Diego Campus Forest 10 of the University of California, San Diego (UCSD), is a rich and varied ecosystem stretching from the Pacific Ocean

Tsien, Roger Y.

373

1, 275309, 2004 Net ecosystem  

E-print Network

BGD 1, 275­309, 2004 Net ecosystem exchange of carbondioxide and water A. J. Dolman et al. Title Discussions Biogeosciences Discussions is the access reviewed discussion forum of Biogeosciences Net ecosystem.dolman@geo.falw.vu.nl) 275 #12;BGD 1, 275­309, 2004 Net ecosystem exchange of carbondioxide and water A. J. Dolman et al

Paris-Sud XI, Université de

374

Gene-based modelling for rice: an opportunity to enhance the simulation of rice growth and development?  

PubMed

Process-based crop simulation models require employment of new knowledge for continuous improvement. To simulate growth and development of different genotypes of a given crop, most models use empirical relationships or parameters defined as genetic coefficients to represent the various cultivar characteristics. Such a loose introduction of different cultivar characteristics can result in bias within a simulation, which could potentially integrate to a high simulation error at the end of the growing season when final yield at maturity is predicted. Recent advances in genetics and biomolecular analysis provide important opportunities for incorporating genetic information into process-based models to improve the accuracy of the simulation of growth and development and ultimately the final yield. This improvement is especially important for complex applications of models. For instance, the effect of the climate change on the crop growth processes in the context of natural climatic and soil variability and a large range of crop management options (e.g., N management) make it difficult to predict the potential impact of the climate change on the crop production. Quantification of the interaction of the environmental variables with the management factors requires fine tuning of the crop models to consider differences among different genotypes. In this paper we present this concept by reviewing the available knowledge of major genes and quantitative trait loci (QTLs) for important traits of rice for improvement of rice growth modelling and further requirements. It is our aim to review the assumption of the adequacy of the available knowledge of rice genes and QTL information to be introduced into the models. Although the rice genome sequence has been completed, the development of gene-based rice models still requires additional information than is currently unavailable. We conclude that a multidiscipline research project would be able to introduce this concept for practical applications. PMID:17915256

Bannayan, Mohammad; Kobayashi, Kazuhiko; Marashi, Hassan; Hoogenboom, Gerrit

2007-12-01

375

ORIGINAL ARTICLE A major effect quantitative trait locus for whirling  

E-print Network

and freshwater ecosystems (Bartholomew and Reno, 2002). Whirling disease has negatively impacted survival ratesORIGINAL ARTICLE A major effect quantitative trait locus for whirling disease resistance identified disease, caused by the pathogen Myxobolus cerebralis, leads to skeletal deformation, neurological

May, Bernie

376

MULTILEVEL SELECTION THEORY AND MAJOR EVOLUTIONARY TRANSITIONS  

E-print Network

, species, and ecosystems as if there was no need to distinguish among levels of the biological hierarchy1 MULTILEVEL SELECTION THEORY AND MAJOR EVOLUTIONARY TRANSITIONS: IMPLICATIONS FOR PSYCHOLOGICAL levels of the biological hierarchy. When between-group selection dominates within-group selection

Wilson, David. S.

377

Sample careers for majors The Career Center  

E-print Network

will continue to grow. Students in our Ecosystem Science and Sustainability major learn to integrate science responsibly. We provide students with a broad base of experiential and collaborative learning opportunities in seasonal and voluntary work, intern- ships, and cooperative education opportunities will enhance your

378

Sample careers for majors The Career Center  

E-print Network

sustainably will continue to grow. Students in our Ecosystem Science and Sustainability major learn resources responsibly. We provide students with a broad base of experiential and collaborative learning in seasonal and voluntary work, intern- ships, and cooperative education opportunities will enhance your

379

Top 10 principles for designing healthy coastal ecosystems  

USGS Publications Warehouse

Like other coastal zones around the world, the inland sea ecosystem of Washington (USA) and British Columbia (Canada), an area known as the Salish Sea, is changing under pressure from a growing human population, conversion of native forest and shoreline habitat to urban development, toxic contamination of sediments and species, and overharvest of resources. While billions of dollars have been spent trying to restore other coastal ecosystems around the world, there still is no successful model for restoring estuarine or marine ecosystems like the Salish Sea. Despite the lack of a guiding model, major ecological principles do exist that should be applied as people work to design the Salish Sea and other large marine ecosystems for the future. We suggest that the following 10 ecological principles serve as a foundation for educating the public and for designing a healthy Salish Sea and other coastal ecosystems for future generations: (1) Think ecosystem: political boundaries are arbitrary; (2) Account for ecosystem connectivity; (3) Understand the food web; (4) Avoid fragmentation; (5) Respect ecosystem integrity; (6) Support nature's resilience; (7) Value nature: it's money in your pocket; (8) Watch wildlife health; (9) Plan for extremes; and (10) Share the knowledge.

Gaydos, Joseph K.; Dierauf, Leslie; Kirby, Grant; Brosnan, Deborah; Gilardi, Kirsten; Davis, Gary E.

2008-01-01

380

Terrestrial ecosystem responses to global change: A research strategy  

SciTech Connect

Uncertainty about the magnitude of global change effects on terrestrial ecosystems and consequent feedbacks to the atmosphere impedes sound policy planning at regional, national, and global scales. A strategy to reduce these uncertainties must include a substantial increase in funding for large-scale ecosystem experiments and a careful prioritization of research efforts. Prioritization criteria should be based on the magnitude of potential changes in environmental properties of concern to society, including productivity; biodiversity; the storage and cycling of carbon, water, and nutrients; and sensitivity of specific ecosystems to environmental change. A research strategy is proposed that builds on existing knowledge of ecosystem responses to global change by (1) expanding the spatial and temporal scale of experimental ecosystem manipulations to include processes known to occur at large scales and over long time periods; (2) quantifying poorly understood linkages among processes through the use of experiments that manipulate multiple interacting environmental factors over a broader range of relevant conditions than did past experiments; and (3) prioritizing ecosystems for major experimental manipulations on the basis of potential positive and negative impacts on ecosystem properties and processes of intrinsic and/or utilitarian value to humans and on feedbacks of terrestrial ecosystems to the atmosphere.

NONE

1998-09-01

381

20-Apr-12 Rice 2032: April 23, 2012 Last name First name Email address School  

E-print Network

@rice.edu Natural Sciences Colvin Vicky colvin@rice.edu Administration Kirby Kevin kevin@rice.edu Engineering Achard Michel achard@rice.edu Humanities DeConick April adeconick@rice.edu Humanities O'Callahan

Alvarez, Pedro J.

382

Ecosystem theory and the unexpected: implications for environmental toxicology  

SciTech Connect

The necessity of considering in research, the components of ecosystems as parts of the dynamic whole is emphasized. Certainly a major focus of toxic substance programs should be understanding effects on the state of the whole ecosystem. In the first section the notion of the system as it emerges from hierarchy theory is developed. The next section emphasizes the ecosystem as a biogeochemical system. Next the focus is placed explicitly on the system-component problem, and ecological examples of problems involved in extrapolating from component measurements to system behaviors are given. Recommendations for toxic substances research are included.

O'Neill, R.V.; Waide, J.B.

1980-01-01

383

Legitimizing Fluvial Ecosystems as Users of Water: An Overview  

Microsoft Academic Search

We suggest that fluvial ecosystems are legitimate users of water and that there are basic ecological principles guiding the\\u000a maintenance of long-term ecological vitality. This article articulates some fundamental relationships between physical and\\u000a ecological processes, presents basic principles for maintaining the vitality of fluvial ecosystems, identifies several major\\u000a scientific challenges and opportunities for effective implementation of the basic ecological principles,

ROBERT J. NAIMAN; STUART E. BUNN; CHRISTER NILSSON; GEOFF E. PETTS; GILLES PINAY; LISA C. THOMPSON

2002-01-01

384

The Ecosystem Services Framework and Natural Capital Conservation  

Microsoft Academic Search

Work at the interface of ecology and economics has inspired a major transformation in the way people think about the environment.\\u000a Increasingly, ecosystems are seen as capital assets, with the potential to generate a stream of vital life-support services\\u000a meriting careful evaluation and investment. We first present the concepts underpinning the ecosystem services framework (ESF),\\u000a laying out the scope and

R. K. Turner; G. C. Daily

2008-01-01

385

Mitigation options for methane emissions from rice fields in the Philippines  

SciTech Connect

The contribution of Philippine rice production to global methane emission and breakthroughs in methane emission studies conducted in the country are presented in this paper. A significant impact in the reduction of GHG emissions from agriculture can be achieved if methane emissions from ricefields can be abated. This study presents the contribution of Philippine rice cultivation to global methane emission and breakthroughs in methane emission studies in the country which address the issue of mitigation. Using the derived emission factors from local measurements, rice cultivation contributes 566.6 Gg of methane emission in the Philippines. This value is 62% of the total methane emitted from the agriculture sector. The emission factors employed which are 78% of the IPCC value for irrigated rice and 95% for rainfed rice were derived from measurements with an automatic system taken during the growth duration in the respective ecosystems. Plots drained for 2 weeks at midtillering and before harvest gave a significant reduction in methane emission as opposed to continuously flooded plots and plots drained before harvest. The cultivar Magat reduced methane emission by 50% as compared to the check variety IR72. The application of ammonium sulfate instead of urea reduced methane emission by 10% to 34%. Addition of 6 t ha{sup {minus}1} phosphogypsum in combination with urea reduced emission by 74% as opposed to plots applied with urea alone. It is also from the results of such measurements that abatement strategies are based as regards to modifying treatments such as water management, fertilization, and choice of rice variety. It is not easy to identify and recommend mitigation strategies that will fit a particular cropping system. However, the identified mitigation options provide focus for the abatement of methane emission from ricefields.

Lantin, R.S.; Buendia, L.V.; Wassmann, R. [International Rice Research Institute, Laguna (Philippines)] [and others

1996-12-31

386

Applied Physics Graduate Program The Rice Quantum Institute  

E-print Network

divisions at Rice, overseen by the Rice Quantum Institute (RQI),theApplied Physics Program (APP87 Applied Physics Graduate Program The Rice Quantum Institute Participating Faculty This program is open to faculty from physics and astronomy, chemistry, mechanicalengineeringandmaterialsscience

Richards-Kortum, Rebecca

387

Building an Ecosystem  

NSDL National Science Digital Library

This activity is designed to follow our students from grade 7 - 12. Each year adds to or builds upon previous years. The project is centered around a 400 gallon, 4 tank system which is placed in sunlight in the lobby of our science building. It was seeded with water from nearby rivers, lakes, ponds, and creeks. The only mechanical part is a pump which returns water from tank 4 back to tank 1. This aquatic ecosystem is a constant, woven through the curriculum as students progress through science. At the end of 3-5 science courses students have greater awareness of the role of detritivores and decomposers in the cycling of matter and understand how human activities may upset the balance in an ecosystem. One goal is for students to see the relationship between what is studied in a classroom and the real world; another is for them to understand the role of wetlands in making water suitable to sustain life.

BEGIN:VCARD VERSION:2.1 FN:Charlotte C. Freeman N:C. Freeman;Charlotte ORG:Girls Preparatory School REV:2005-04-08 END:VCARD

1995-06-30

388

[Identification and classification of rice leaf blast based on multi-spectral imaging sensor].  

PubMed

Site-specific variable pesticide application is one of the major precision crop production management operations. Rice blast is a severe threat for rice production. Traditional chemistry methods can do the accurate crop disease identification, however they are time-consuming, require being executed by professionals and are of high cost. Crop disease identification and classification by human sight need special crop protection knowledge, and is low efficient. To obtain fast, reliable, accurate rice blast disease information is essential for achieving effective site-specific pesticide applications and crop management. The present paper describes a multi-spectral leaf blast identification and classification image sensor, which uses three channels of crop leaf and canopy images. The objective of this work was to develop and evaluate an algorithm under simplified lighting conditions for identifying damaged rice plants by the leaf blast using digital color images. Based on the results obtained from this study, the seed blast identification accuracy can be achieved at 95%, and the leaf blast identification accuracy can be achieved at 90% during the rice growing season. Thus it can be concluded that multi-spectral camera can provide sufficient information to perform reasonable rice leaf blast estimation. PMID:20038048

Feng, Lei; Chai, Rong-Yao; Sun, Guang-Ming; Wu, Di; Lou, Bing-Gan; He, Yong

2009-10-01

389

The effects of climate change on United States rice yields and California wheat yields  

SciTech Connect

The USA produces 7.9 million tons of rice (Oryza sativa L.), 28% of which is exported to developing countries. Rice is one of the most important grain crops both in the USA and the world. Therefore it is important to understand the impact of weather and climate change on rice yields and production. In the USA rice is produced in California and the Gulf Coast states. It is anticipated that global climate change will have a major influence on agricultural practices and crop selection in these states. This study uses simulation techniques to quantify the potential magnitude of this influence. In addition, the impact of climate change on fall planted dryland spring wheat (Triticum aestivum L.) in California is evaluated. Results indicate that rice yields decrease by between 14 and 24% in the Gulf Coast states and between 11 and 21% in California. In both regions the decrease in rice yields were due primarily to the large increase in summer temperatures. On the other hand, dryland fall planted spring wheat yields in California increase by 62 and 125%. This is because of the increased rainfall and temperatures during the winter months in California.

Barry, T.A.; Geng, S. [Univ. of California, Davis, CA (United States)

1995-12-31

390

Phytoremediation of arsenic contaminated paddy soils with Pteris vittata markedly reduces arsenic uptake by rice.  

PubMed

Arsenic (As) accumulation in food crops such as rice is of major concern. To investigate whether phytoremediation can reduce As uptake by rice, the As hyperaccumulator Pteris vittata was grown in five contaminated paddy soils in a pot experiment. Over a 9-month period P. vittata removed 3.5-11.4% of the total soil As, and decreased phosphate-extractable As and soil pore water As by 11-38% and 18-77%, respectively. Rice grown following P. vittata had significantly lower As concentrations in straw and grain, being 17-82% and 22-58% of those in the control, respectively. Phytoremediation also resulted in significant changes in As speciation in rice grain by greatly decreasing the concentration of dimethylarsinic acid (DMA). In two soils the concentration of inorganic As in rice grain was decreased by 50-58%. The results demonstrate an effective stripping of bioavailable As from contaminated paddy soils thus reducing As uptake by rice. PMID:21840633

Ye, Wen-Ling; Khan, M Asaduzzaman; McGrath, Steve P; Zhao, Fang-Jie

2011-12-01

391

Potential of Rice Husk and Rice Husk Ash for Phenol Removal in Aqueous Systems  

Microsoft Academic Search

The potential of rice husk and rice husk ash for phenol adsorption from aqueous solution was studied. Batch kinetics and isotherm studies were carried out under varying experimental conditions of contact time, phenol concentration, adsorbent dose and pH. Adsorption equilibrium of rice husk and rice husk ash was reached within 6 hr for phenolic concentration 150-500 µg\\/L and 3 hr

A. H. Mahvi; A. Maleki; A. Eslami

2004-01-01

392

???????????????????????????????????????????????????????????????????????? EFFECT OF DRY AND WET-MILLING PROCESSES ON RICE FLOUR AND RICE NOODLE PROPERTIES  

Microsoft Academic Search

In this research, the chemical and physicochemical properties of low amylose (Pathum Thani 1), medium amylose (RD 7) and high amylose (Leuang 11) milled rices prepared from dry- and wet-milling processes were determined. Protein and fat contents of dry-milled rice flours were significantly higher (P?0.05) than those of wet-milled rice flours in all rice varieties. There was a higher degree

Anocha Suksomboon; Onanong Naivikul

393

Construction of a rice glycoside hydrolase phylogenomic database and identification of targets for biofuel research  

PubMed Central

Glycoside hydrolases (GH) catalyze the hydrolysis of glycosidic bonds in cell wall polymers and can have major effects on cell wall architecture. Taking advantage of the massive datasets available in public databases, we have constructed a rice phylogenomic database of GHs (http://ricephylogenomics.ucdavis.edu/cellwalls/gh/). This database integrates multiple data types including the structural features, orthologous relationships, mutant availability, and gene expression patterns for each GH family in a phylogenomic context. The rice genome encodes 437 GH genes classified into 34 families. Based on pairwise comparison with eight dicot and four monocot genomes, we identified 138 GH genes that are highly diverged between monocots and dicots, 57 of which have diverged further in rice as compared with four monocot genomes scanned in this study. Chromosomal localization and expression analysis suggest a role for both whole-genome and localized gene duplications in expansion and diversification of GH families in rice. We examined the meta-profiles of expression patterns of GH genes in twenty different anatomical tissues of rice. Transcripts of 51 genes exhibit tissue or developmental stage-preferential expression, whereas, seventeen other genes preferentially accumulate in actively growing tissues. When queried in RiceNet, a probabilistic functional gene network that facilitates functional gene predictions, nine out of seventeen genes form a regulatory network with the well-characterized genes involved in biosynthesis of cell wall polymers including cellulose synthase and cellulose synthase-like genes of rice. Two-thirds of the GH genes in rice are up regulated in response to biotic and abiotic stress treatments indicating a role in stress adaptation. Our analyses identify potential GH targets for cell wall modification. PMID:23986771

Sharma, Rita; Cao, Peijian; Jung, Ki-Hong; Sharma, Manoj K.; Ronald, Pamela C.

2013-01-01

394

Midday photoinhibition of two newly developed super-rice hybrids  

Microsoft Academic Search

Super-rice hybrids are two-line hybrid rice cultivars with 15 to 20 % higher yields than the raditional three-line hybrid rice cultivars. Response of photosynthetic functions to midday photoinhibition was compared between seedlings of the traditional hybrid rice (Oryza sativa L.) Shanyou63 and two super-rice hybrids, Hua-an3 and Liangyoupeijiu. Under strong midday sunlight, in comparison with Shanyou63, the two super-rice hybrids

Q. A. Wang; C. M. Lu; Q. D. Zhang

2005-01-01

395

PIXE analyses of cesium in rice grains  

NASA Astrophysics Data System (ADS)

The Fukushima nuclear power plant accident released vast amounts of radioactive material into the environment. For instance, 134Cs and 137Cs have half-lives of about 2 and 30 years, respectively, and emit many harmful gamma rays. In 2012, rice with radioactivity >100 Bq/kg was occasionally reported in Fukushima prefecture. To determine where and how cesium accumulates in rice, we grew rice in soil containing stable cesium and investigated the distribution of cesium in rice using particle-induced X-ray emission (PIXE). This study found that cesium is accumulated in bran and germ at high concentrations, and white rice contains 40% of the cesium found in brown rice.

Sugai, Hiroyuki; Ishii, Keizo; Matsuyama, Shigeo; Terakawa, Atsuki; Kikuchi, Yohei; Takahashi, Hiroaki; Ishizaki, Azusa; Fujishiro, Fumito; Arai, Hirotsugu; Osada, Naoyuki; Karahashi, Masahiro; Nozawa, Yuichiro; Yamauchi, Shosei; Kikuchi, Kosuke; Koshio, Shigeki; Watanabe, Koji

2014-01-01

396

Water consumption of agriculture and natural ecosystems at the Amu Darya in Lebap Province, Turkmenistan  

NASA Astrophysics Data System (ADS)

The Amu Darya is the main water source for whole Turkmenistan, but also for the regions Khorezm and Karakalpakistan in Uzbekistan. Due to the arid climate in the Amu Darya river basin, agriculture depends on irrigation with river water being the major source of water. Also the natural ecosystems depend on river water. Until end of the 1970s, the Amu Darya flew into the Aral Sea and, together with the Syr Darya, sustained its water level. From the 1960s until today the area under irrigation has been strongly enlarged. During Soviet Union times, mainly cotton was planted on the newly reclaimed land. After independence, new land was reclaimed, in order to grow wheat. In the course of this land reclamation, the downstream section of the Amu Darya, i.e. in Karakalpakistan faces severe water shortage. Today, the Amu Darya only occasionally reaches the previous shore line of the Aral Sea. Against this background, it is necessary that water consumption along the Amu Darya is limited and water is used efficiently, in order to ensure water supply for downstream water users. The province Lebap in Turkmenistan is located at the middle reaches of the Amu Darya. Thus, it is an example of an administrative unit, which consumes water from the Amu Darya and which should release a sufficient amount of water downstream. Furthermore, Lebap harbours one of the last near-natural riparian forests of Central Asia, i.e. the Amu Darya State Reserve, which also is a water consumer. Therefore, we estimate the water consumption of agriculture (cotton, wheat, rice, and house gardens) and the natural ecosystems within Lebap Province. Water consumption refers to the actual evapo-transpiration. We use Landsat ETM and TM satellite images, in order to produce maps of the actual evapo-transpiration. Afterwards, a land cover map is laid over the ETa maps, in order to retrieve the ETa of the different crops and natural ecosystems. These results are compared with the water norms and quotas given for Lebap Province.

Thevs, Niels; Ovezmuradov, Kurban

2013-04-01

397

Obscuring ecosystem function with application of the ecosystem services concept.  

PubMed

Conservationists commonly have framed ecological concerns in economic terms to garner political support for conservation and to increase public interest in preserving global biodiversity. Beginning in the early 1980s, conservation biologists adapted neoliberal economics to reframe ecosystem functions and related biodiversity as ecosystem services to humanity. Despite the economic success of programs such as the Catskill/Delaware watershed management plan in the United States and the creation of global carbon exchanges, today's marketplace often fails to adequately protect biodiversity. We used a Marxist critique to explain one reason for this failure and to suggest a possible, if partial, response. Reframing ecosystem functions as economic services does not address the political problem of commodification. Just as it obscures the labor of human workers, commodification obscures the importance of the biota (ecosystem workers) and related abiotic factors that contribute to ecosystem functions. This erasure of work done by ecosystems impedes public understanding of biodiversity. Odum and Odum's radical suggestion to use the language of ecosystems (i.e., emergy or energy memory) to describe economies, rather than using the language of economics (i.e., services) to describe ecosystems, reverses this erasure of the ecosystem worker. Considering the current dominance of economic forces, however, implementing such solutions would require social changes similar in magnitude to those that occurred during the 1960s. Niklas Luhmann argues that such substantive, yet rapid, social change requires synergy among multiple societal function systems (i.e., economy, education, law, politics, religion, science), rather than reliance on a single social sphere, such as the economy. Explicitly presenting ecosystem services as discreet and incomplete aspects of ecosystem functions not only allows potential economic and environmental benefits associated with ecosystem services, but also enables the social and political changes required to ensure valuation of ecosystem functions and related biodiversity in ways beyond their measurement on an economic scale. PMID:19659684

Peterson, Markus J; Hall, Damon M; Feldpausch-Parker, Andrea M; Peterson, Tarla Rai

2010-02-01

398

Incorporating Regional Rice Production Models in Rice Importation Simulation Model: a Stochastic Programming Approach  

Microsoft Academic Search

In the Philippines, importation has remained as one of the most feasible options for the government to meet the growing demand for rice. It is thus imperative for the government to develop a strategy that would ensure adequate supply and minimum importation costs. One of the critical factors in import decisionmaking is rice production. The Inter-Agency Committee on Rice and

Celia M Reyes; Rosalina G. de Guzman; Christian D. Mina; Jason Crean; Kevin Parton

2009-01-01

399

Rice University | Rice Facts Index Undergraduates Graduates Faculty & Researchers Staff Alumni  

E-print Network

Historical Facts Archives About OIR Rice News Feed Font Size Rice Facts Rice Culture Mission History about itself. This organizational intelligence function reflects the demand for increasingly and competitive environments. OIR uses a significant amount of time, resources and human capital in conducting

Richards-Kortum, Rebecca

400

Texas Rice, Volume VII, Number 1  

E-print Network

.......................10 Statement from Mexico on GMO Rice ................................ 10 United States, Brazil Cooperate on Biofuels ....................... 12 Cover Story: The Indica Revolution Welcome again to Tex- as Rice. This issue marks the beginning of our... guarantee accuracy or completeness. Suggestions, story ideas and comments are encouraged. Rice Crop Update During a visit to Brazil, on March 8, President Bush signed an agreement with his counterpart, President Luiz Inácio Lula da Silva, to strengthen...

401

Texas Rice, Volume V, Number 6  

E-print Network

surface with crop residue after planting (Texas Rice, 2005). Conservation tillage has proven to be an extremely efficient and effective tool for reducing erosion, protecting the quality of surface and ground wa- ter, and providing habitat for a variety... of wildlife species (Texas Rice, 2005). The potential benefits of conservation tillage include reduced labor, time and fuel use, reduced machinery wear, higher soil mois- ture, and reduced runoff (Texas Rice, 2005). Conser- vation tillage often reduces...

402

Physical properties of cryomilled rice starch  

Microsoft Academic Search

Cryomilling of rice starch was evaluated as a non-chemical way to modify starch structure and properties. Cryomilling in a liquid nitrogen bath (63–77.2K) was done to Quest (10.80% amylose) and Pelde (20.75% amylose) rice starch at five different time frames (0, 15, 30, 45, and 60min). The viscosity of the cryomilled rice starch decreased significantly (p<0.05) with increasing milling duration,

A. F. Devi; K. Fibrianto; P. J. Torley; B. Bhandari

2009-01-01

403

Meeting the challenges of global rice production  

Microsoft Academic Search

Rice is the second most widely grown cereal crop and the staple food for more than half the world's population. More than\\u000a 3 billion people consume more than 100 kg of rice per year. Rice is cultivated on 155.5 million ha with an average growth\\u000a rate of 0.39% a year, in the last 30 years. In the near future, the possibility

Nguu Van Nguyen; Aldo Ferrero

2006-01-01

404

Research on Rice Production in Texas.  

E-print Network

, Beaumont, Texas, during the past 10 years. These include the development and testing of new and superior varieties of rice; time, methods and rates of seeding; time, methods and rates of application of fertilizers; studies on irrigation; control of weeds...! lfate of ammonia, urea and cyanamid were better sources of nitrogen for rice than nitrate of soda. .rieties of rice of different maturity responded differently to dates of application of fertilizers. early and midseason varieties are to be grown...

Reynolds, E. B.

1954-01-01

405

Sorting of rice grains using Zernike moments  

Microsoft Academic Search

Two important factors that determine the efficiency and reliability of a rice sorting machine are the overall processing speed\\u000a and the classification accuracy. In this paper, an efficient rice sorting process which uses a subset of Zernike moments (ZM)\\u000a and a multilayer perceptron is presented. Since the falling rice grains during sorting process can be in any orientation,\\u000a a rotational

Chong-Yaw Wee; Paramesran Raveendran; Fumiaki Takeda

2009-01-01

406

Decomposition of rice residue in tropical soils  

Microsoft Academic Search

Nitrogen mineralization and immobilization of rice residue in Maahas clay soil under lowland and upland conditions were investigated by using N-labelled rice straw. The mineralization of residue-nitrogen was taking place even though the net mineralization was depressed by incorporation of rice residue.There were some significant differences in the pattern of nitrogen transformation between lowland and upland soil conditions. The nitrogen

Tadakatsu Yoneyama; Tomio Yoshida

1977-01-01

407

The effects of rice and soybean pesticides on the eggs of Psorophora columbiae (Dyar and Knab) (Diptera: Culicidae)  

E-print Network

THE EFFECTS OF RICE AND SOYBEAN PESTICIDES ON THE EGGS OF PSOROPHORA COLUMBIAE (DYAR AND KNAB) (DIPTERA: CULICIDAE) A Thesis by MARTIN CHARLES KLASS Submitted to the Graduate College of Texas ARM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1983 Major Subject: Entomology THE EFFECTS OF RICE AND SOYBEAN PESTICIDES ON THE EGGS OF PSOROPHORA COLUMBIAE (DYAR AND KNAB) (DIPTERA: CULICIDAE) A Thesis by MARTIN CHARLES KLASS Approved...

Klass, Martin Charles

2012-06-07

408

An analysis of the teaching methods and sources of information used in adopting improved practices in rice production in Texas  

E-print Network

AN ANALYSIS QF THE TEACHING METHODS AND SOURCES OF INFORMATION USED IN ADOPTING IMPROVED PRACTICES IN RICE PRODUCTION IN TEXAS A Thesis by A. K. M. Anwarul Kibria Submitted to the Graduate College of the Texas A&M University in partial... fulfillment of the requirments for tne degree of MASTER OF SCIENCE August 1967 Major Subject: Agricultural Education AN ANALYSIS OF THE TEACHING METHODS AND SOURCES QF INFORMATION USED IN ADOPTING IMPROVED PRACTICES IN RICE PRODUCTION IN TEXAS A Thesis...

Kibria, A. K. M. Anwarul

2012-06-07

409

Microbial community composition controls the effects of climate change on methane emission from rice paddies.  

PubMed

Rice paddies are one of the most important sources of CH4 emission from the terrestrial ecosystem. A Free-air CO2 Enrichment (FACE) experiment, which included a soil warming treatment, was conducted in a rice paddy at Shizukuishi, Japan. In this study, the changes in CH4 emission from a rice paddy, caused by global climate change, were explored in relation to the structural changes that have occurred in the methanogenic archaeal communities found in the soil and roots. The composition of the archaeal community was examined by terminal restriction fragment length polymorphism (T-RFLP) using the 16S rRNA gene, while its abundance was measured by real-time PCR using the methyl coenzyme M reductase (mcrA) gene. The archaeal community in the roots showed considerable change, characterized by the dominance of hydrogenotrophic methanogens and a corresponding decrease in acetoclastic methanogens. Seasonal changes in CH4 flux were closely related to the changes in methanogen abundance in the roots. Elevated CO2 caused an increase in root mass, which increased the abundance of methanogens leading to a rise in CH4 emissions. However, soil warming stimulated CH4 emissions by increasing CH4 production per individual methanogen. These results demonstrated that climate warming stimulates CH4 emission in a rice paddy by altering the abundance and activity of methanogenic archaea in the roots. PMID:23760936

Liu, Guang Cheng; Tokida, Takesi; Matsunami, Toshinori; Nakamura, Hirofumi; Okada, Masumi; Sameshima, Ryoji; Hasegawa, Toshihiro; Sugiyama, Shu-Ichi

2012-12-01

410

Bioethanol production from rice straw residues  

PubMed Central

A rice straw - cellulose utilizing mold was isolated from rotted rice straw residues. The efficient rice straw degrading microorganism was identified as Trichoderma reesei. The results showed that different carbon sources in liquid culture such as rice straw, carboxymethyl cellulose, filter paper, sugar cane bagasse, cotton stalk and banana stalk induced T. reesei cellulase production whereas glucose or Potato Dextrose repressed the synthesis of cellulase. T. reesei cellulase was produced by the solid state culture on rice straw medium. The optimal pH and temperature for T. reesei cellulase production were 6 and 25 °C, respectively. Rice straw exhibited different susceptibilities towards cellulase to their conversion to reducing sugars. The present study showed also that, the general trend of rice straw bioconversion with cellulase was more than the general trend by T. reesei. This enzyme effectively led to enzymatic conversion of acid, alkali and ultrasonic pretreated cellulose from rice straw into glucose, followed by fermentation into ethanol. The combined method of acid pretreatment with ultrasound and subsequent enzyme treatment resulted the highest conversion of lignocellulose in rice straw to sugar and consequently, highest ethanol concentration after 7 days fermentation with S. cerevisae yeast. The ethanol yield in this study was about 10 and 11 g.L?1. PMID:24159309

Belal, Elsayed B.

2013-01-01

411

Texas Rice, Volume III, Number 2  

E-print Network

results in these systems. Jackson County rice farmer Hal Koop has worked with Marvin for many years on various problems such as crown rot, stem rot and salt problems in his rice fields. According to Hal, Marvin has been a tremen- dous resource... results in these systems. Jackson County rice farmer Hal Koop has worked with Marvin for many years on various problems such as crown rot, stem rot and salt problems in his rice fields. According to Hal, Marvin has been a tremen- dous resource...

412

RICE UNIVERSITY Computational Modeling of Icon Search  

E-print Network

1 RICE UNIVERSITY Computational Modeling of Icon Search by Michael D. Fleetwood A THESIS SUBMITTED: ______________________________ Michael D. Byrne, Assistant Professor Psychology #12;2 ______________________________ David M. Lane

Byrne, Mike

413

Total arsenic in rice milk.  

PubMed

Rice milk and its by-products were tested for total arsenic concentration. Total arsenic concentration was determined using graphite-furnace atomic absorption spectrometry. The arsenic concentrations ranged from 2.7 ± 0.3 to 17.9 ± 0.5 µg L(-1). Rice milk and its by-products are not clearly defined as food, water or milk substitute. The US Environmental Protection Agency (EPA), the European Union (EU) and the World Health Organization (WHO) have set a level of 10 µg L(-1) for total arsenic concentrations in drinking water. The EU and the US regulatory agencies do not provide any guidelines on total arsenic concentrations in foods. This study provides us with a starting point to address this issue in the State of Mississippi, USA. PMID:24779982

Shannon, Ron; Rodriguez, Jose M

2014-03-01

414

Resilience, Integrity and Ecosystem Dynamics: Bridging Ecosystem Theory and Management  

NASA Astrophysics Data System (ADS)

In this paper different approaches to elucidate ecosystem dynamics are described, illustrated and interrelated. Ecosystem development is distinguished into two separate sequences, a complexifying phase which is characterized by orientor optimization and a destruction based phase which follows disturbances. The two developmental pathways are integrated in a modified illustration of the "adaptive cycle". Based on these fundamentals, the recent definitions of resilience, adaptability and vulnerability are discussed and a modified comprehension is proposed. Thereafter, two case studies about wetland dynamics are presented to demonstrate both, the consequences of disturbance and the potential of ecosystem recovery. In both examples ecosystem integrity is used as a key indicator variable. Based on the presented results the relativity and the normative loading of resilience quantification is worked out. The paper ends with the suggestion that the features of adaptability could be used as an integrative guideline for the analysis of ecosystem dynamics and as a well-suited concept for ecosystem management.

Müller, Felix; Burkhard, Benjamin; Kroll, Franziska

415

Resilience, Integrity and Ecosystem Dynamics: Bridging Ecosystem Theory and Management  

NASA Astrophysics Data System (ADS)

In this paper different approaches to elucidate ecosystem dynamics are described, illustrated and interrelated. Ecosystem development is distinguished into two separate sequences, a complexifying phase which is characterized by orientor optimization and a destruction based phase which follows disturbances. The two developmental pathways are integrated in a modified illustration of the “adaptive cycle”. Based on these fundamentals, the recent definitions of resilience, adaptability and vulnerability are discussed and a modified comprehension is proposed. Thereafter, two case studies about wetland dynamics are presented to demonstrate both, the consequences of disturbance and the potential of ecosystem recovery. In both examples ecosystem integrity is used as a key indicator variable. Based on the presented results the relativity and the normative loading of resilience quantification is worked out. The paper ends with the suggestion that the features of adaptability could be used as an integrative guideline for the analysis of ecosystem dynamics and as a well-suited concept for ecosystem management.

Müller, Felix; Burkhard, Benjamin; Kroll, Franziska

416

Genetic analysis of rice varietal diversity for rice blast control.  

PubMed

Two Indica hybrid rice of Shanyou63 (A) and Shanyou22 (B), two glutinous landraces of Huanghenuo (C) and Zinuo (D) and three improved Japonica rice of Hexi41 (E), Chujing12 (F) and 8126 (G) were selected and their genetic resistance relationship was estimated using resistance gene analogue (RGA). The results showed that there were similar genetic relationships between hybrid varieties at the genetic similarity (GS) of 0.86,and among improved Japonica varieties at the GS of 0.84, while highly genetic diversifications between traditional varieties, Indica and Japonica varieties, traditional and modern variety ( GS:0.45). The results also showed that clustering analysis based on RGA data were generally corresponded to known pedigrees and blast field resistances of the varieties. Based on varietal differences in RGA data and agronomic traits, plot experiments of five mixed-planting combinations of A/C, A/D, B/C, B/D and A/B and two combinations of E/C and E/F/G were conducted in Jianshui and Shiping counties ( Indica rice growing region) and Luxi County (warm Japonica region) in Yunnan Province in past two years, respectively. The results demonstrated that rice blast management was more effective in five mixed-planting combinations of varieties with different genetic backgrounds (GS: 0.45-0.77) than in two combinations with similar genetic relationships (GS: 0.84-0.90), compared with their monocultures. It is evident for the highly susceptible landraces in mixed-planting to achieve disease control, with significant decreases both in incidence and severity. The blast control efficiencies of landraces in different mixture combinations reached to 54.47%-92.18%. The control efficiencies of improved varieties varied from 15.12% to 25.54% in mixture combinations with closed genetic relationship. In addition,the total yield of 5 varietal combinations with distant genetic relationship increased 539.0-904.0 kg/ha in the mixed-planting plots, at increase rates of 5.6%-10.2%. Mixed rice varieties with similar genetic background did not achieve significant yield increase. Otherwise, the yield of E/F/G decreased 2.7%-4.0% compared with pure stand. The results can provide scientific basis of varietal combinations in diversification experiments for blast control. PMID:15473323

Zhu, You-Yong; Sun, Yan; Wang, Yun-Yue; Li, Yan; He, Yue-Qiu; He, Xia-Hong; Mundt, Christopher C; Mew, Tom W; Hei, Leung

2004-07-01

417

Development of disease-resistant rice using regulatory components of induced disease resistance  

PubMed Central

Infectious diseases cause huge crop losses annually. In response to pathogen attacks, plants activate defense systems that are mediated through various signaling pathways. The salicylic acid (SA) signaling pathway is the most powerful of these pathways. Several regulatory components of the SA signaling pathway have been identified, and are potential targets for genetic manipulation of plants’ disease resistance. However, the resistance associated with these regulatory components is often accompanied by fitness costs; that is, negative effects on plant growth and crop yield. Chemical defense inducers, such as benzothiadiazole and probenazole, act on the SA pathway and induce strong resistance to various pathogens without major fitness costs, owing to their ‘priming effect.’ Studies on how benzothiadiazole induces disease resistance in rice have identified WRKY45, a key transcription factor in the branched SA pathway, and OsNPR1/NH1. Rice plants overexpressing WRKY45 were extremely resistant to rice blast disease caused by the fungus Magnaporthe oryzae and bacterial leaf blight disease caused by Xanthomonas oryzae pv. oryzae (Xoo), the two major rice diseases. Disease resistance is often accompanied by fitness costs; however, WRKY45 overexpression imposed relatively small fitness costs on rice because of its priming effect. This priming effect was similar to that of chemical defense inducers, although the fitness costs were amplified by some environmental factors. WRKY45 is degraded by the ubiquitin–proteasome system, and the dual role of this degradation partly explains the priming effect. The synergistic interaction between SA and cytokinin signaling that activates WRKY45 also likely contributes to the priming effect. With a main focus on these studies, I review the current knowledge of SA-pathway-dependent defense in rice by comparing it with that in Arabidopsis, and discuss potential strategies to develop disease-resistant rice using signaling components.

Takatsuji, Hiroshi

2014-01-01

418

Texas Rice, Highlights in Research  

E-print Network

resources and a longer developmental period. In addition to unraveling the above effects, which lead to improved management schemes, we are evaluat- ing the timing of gibberellin applied at several days post-flowering to late grain fill. This treatment... tremendous success in using molecular markers, or “gene-tags”, to assist breeders in identifying and selecting breeding progeny containing desired blast resistance genes. Because single rice genes are known to confer clear and complete resistance to several...

2005-01-01

419

From genes to ecosystems: a genetic basis to ecosystem services  

Microsoft Academic Search

Ecosystems provide services, many of which are regulated through species interactions. Emerging research in the fields of\\u000a community and ecosystem genetics indicate that genetic variation in one species can influence species interactions and affect\\u000a subsequent patterns of energy flow and nutrient cycles. Because there can be a genetic basis to community- and ecosystem-level\\u000a processes, evolutionary processes that alter standing genetic

Joseph K. Bailey

2011-01-01

420

Proteomics of rice seed germination  

PubMed Central

Seed is a condensed form of plant. Under suitable environmental conditions, it can resume the metabolic activity from physiological quiescent status, and mobilize the reserves, biosynthesize new proteins, regenerate organelles, and cell membrane, eventually protrude the radicle and enter into seedling establishment. So far, how these activities are regulated in a coordinated and sequential manner is largely unknown. With the availability of more and more genome sequence information and the development of mass spectrometry (MS) technology, proteomics has been widely applied in analyzing the mechanisms of different biological processes, and proved to be very powerful. Regulation of rice seed germination is critical for rice cultivation. In recent years, a lot of proteomic studies have been conducted in exploring the gene expression regulation, reserves mobilization and metabolisms reactivation, which brings us new insights on the mechanisms of metabolism regulation during this process. Nevertheless, it also invokes a lot of questions. In this mini-review, we summarized the progress in the proteomic studies of rice seed germination. The current challenges and future perspectives were also discussed, which might be helpful for the following studies. PMID:23847647

He, Dongli; Yang, Pingfang

2013-01-01

421

Uncovering legumain genes in rice.  

PubMed

Legumains are Asn specific cysteine proteases physiologically related to the biosynthesis of vacuolar components, degradation of storage proteins and programmed cell death. The present work identifies and characterizes the genic family of legumains in rice (Oryza sativa), which comprises five different loci. Rice legumains (OsaLegs) were ubiquitously detected in all plant tissues analyzed. However, phylogenetic analyses and gene expression studies demonstrated greater association of OsaLeg2 and OsaLeg3 to seed-related legumains, whereas OsaLeg1, 4 and 5 would act as vegetative-related proteases. Additionally, OsaLeg1 mRNA is strongly induced in senescent leaves. All rice legumain genes respond in different ways to environmental conditions such as wounding, salt and abscisic acid treatments. Mainly, wounding is capable of inducing all the four expressed genes OsaLeg1, 2, 3 and 4. Alternative splicing isoforms, with potential to generate pre-activated OsaLeg1 and OsaLeg2 nonvacuolar enzymes under different environmental situations were also observed. PMID:24388520

Christoff, Ana Paula; Turchetto-Zolet, Andreia Carina; Margis, Rogerio

2014-02-01

422

Creation of resveratrol-enriched rice for the treatment of metabolic syndrome and related diseases.  

PubMed

Resveratrol has been clinically shown to possess a number of human health benefits. As a result, many attempts have been made to engineer resveratrol production in major cereal grains but have been largely unsuccessful. In this study, we report the creation of a transgenic rice plant that accumulates 1.9 µg resveratrol/g in its grain, surpassing the previously reported anti-metabolic syndrome activity of resveratrol through a synergistic interaction between the transgenic resveratrol and the endogenous properties of the rice. Consumption of our transgenic resveratrol-enriched rice significantly improved all aspects of metabolic syndrome and related diseases in animals fed a high-fat diet. Compared with the control animals, the resveratrol-enriched rice reduced body weight, blood glucose, triglycerides, total cholesterol, and LDL-cholesterol by 24.7%, 22%, 37.4%, 27%, and 59.6%, respectively. The resveratrol-enriched rice from our study may thus provide a safe and convenient means of preventing metabolic syndrome and related diseases without major lifestyle changes or the need for daily medications. These results also suggest that future transgenic plants could be improved if the synergistic interactions of the transgene with endogenous traits of the plant are considered in the experimental design. PMID:23483945

Baek, So-Hyeon; Shin, Woon-Chul; Ryu, Hak-Seung; Lee, Dae-Woo; Moon, Eunjung; Seo, Chun-Sun; Hwang, Eunson; Lee, Hyun-Seo; Ahn, Mi-Hyun; Jeon, Youngju; Kang, Hyeon-Jung; Lee, Sang-Won; Kim, Sun Yeou; D'Souza, Roshan; Kim, Hyeon-Jin; Hong, Seong-Tshool; Jeon, Jong-Seong

2013-01-01

423

Molecular aspect of good eating quality formation in Japonica rice.  

PubMed

The composition of amylopectin is the determinant of rice eating quality under certain threshold of protein content and the ratio of amylose and amylopectin. In molecular biology level, the fine structure of amylopectin is determined by relative activities of starch branching enzyme (SBE), granule-bound starch synthase (GBSS), and soluble starch synthase (SSS) in rice grain under the same ADP-Glucose level. But the underlying mechanism of eating quality in molecular biology level remains unclear. This paper reports the differences on major parameters such as SNP and insertion-deletion sites, RNA expressions, and enzyme activities associated with eating quality of japonica varieties. Eight japonica rice varieties with significant differences in various eating quality parameters such as palatability and protein content were used in this experiment. Association analysis between nucleotide polymorphism and eating quality showed that S12 and S13 loci in SBE1, S55 in SSS1, S58 in SSS2A were significantly associated with apparent amylose content, alkali digestion value, setback viscosity, consistency viscosity, pasting temperature, which explained most of the variation in apparent amylose content, setback viscosity, and consistency viscosity; and explained almost all variations in alkali digestion value and pasting temperature. Thirty-five SNPs and insertion-deletions from SBE1, SBE3, GBSS1, SSS1, and SSS2A differentiated high or intermediate palatability rice varieties from low palatability rice varieties. Correlation analysis between enzyme activities and eating quality properties revealed that SBE25 and SSS15/W15 were positively correlated with palatability, whereas GBSS10 and GBSS15 were negatively correlated. Gene expressions showed that SBE1 and SBE3 expressions in high palatability varieties tended to be higher than middle and low palatability varieties. Collectively, SBE1, SBE3, SSS1, and SSS2A, especially SBE1 and SBE3 could improve eating quality, but GBSS1 decreased eating quality. The results indicated the possibility of developing high palatability cultivars through modification of key genes related to japonica rice eating quality formation in starch biosynthesis. PMID:21494675

Sun, Ming-Mao; Abdula, Sailila E; Lee, Hye-Jung; Cho, Young-Chan; Han, Long-Zhi; Koh, Hee-Jong; Cho, Yong-Gu

2011-01-01

424

Towards an Analysis of the Rice Mitochondrial Proteome1  

PubMed Central

Purified rice (Oryza sativa) mitochondrial proteins have been arrayed by isoelectric focusing/polyacrylamide gel electrophoresis (PAGE), by blue-native (BN) PAGE, and by reverse-phase high-performance liquid chromatography (LC) separation (LC-mass spectrometry [MS]). From these protein arrays, we have identified a range of rice mitochondrial proteins, including hydrophilic/hydrophobic proteins (grand average of hydropathicity = ?1.27 to +0.84), highly basic and acid proteins (isoelectric point = 4.0–12.5), and proteins over a large molecular mass range (6.7–252 kD), using proteomic approaches. BN PAGE provided a detailed picture of electron transport chain protein complexes. A total of 232 protein spots from isoelectric focusing/PAGE and BN PAGE separations were excised, trypsin digested, and analyzed by tandem MS (MS/MS). Using this dataset, 149 of the protein spots (the products of 91 nonredundant genes) were identified by searching translated rice open reading frames from genomic sequence and six-frame translated rice expressed sequence tags. Sequence comparison allowed us to assign functions to a subset of 85 proteins, including many of the major function categories expected for this organelle. A further six spots were matched to rice sequences for which no specific function has yet been determined. Complete digestion of mitochondrial proteins with trypsin yielded a peptide mixture that was analyzed directly by reverse-phase LC via organic solvent elution from a C-18 column (LC-MS). These data yielded 170 MS/MS spectra that matched 72 sequence entries from open reading frame and expressed sequence tag databases. Forty-five of these were obtained using LC-MS alone, whereas 28 proteins were identified by both LC-MS and gel-based separations. In total, 136 nonredundant rice proteins were identified, including a new set of 23 proteins of unknown function located in plant mitochondria. We also report the first direct identification, to our knowledge, of PPR (pentatricopeptide repeat) proteins in the plant mitochondrial proteome. This dataset provides the first extensive picture, to our knowledge, of mitochondrial functions in a model monocot plant. PMID:12746528

Heazlewood, Joshua L.; Howell, Katharine A.; Whelan, James; Millar, A. Harvey

2003-01-01

425

[Extraction and purification method of rice DNA from rice powder containing Konjak flour].  

PubMed

Rice powder containing Konjak flour made with tuberous roots of Amorphophallus konjac is imported as a rice-processed product from China to Japan. An improved DNA purification method for the polymerase chain reaction (PCR) analysis of rice in such products is necessary, since Konjak flour constituents absorb the DNA purification buffer to form a gel, and cause problems in the subsequent purification steps. Here, we present a simple preparative system for isolation of the rice and a purification method of the rice DNA from the product. The purified DNA was confirmed to be a good template for both PCR and real-time PCR. PMID:21071909

Minematsu, Kazuhiko; Nakamura, Kosuke; Akiyama, Hiroshi; Harikai, Naoki; Nakajima, Osamu; Kitta, Kazumi; Teshima, Reiko; Iizuka, Tayoshi

2010-01-01

426

Growth in rice cells requires de novo purine biosynthesis by the blast fungus Magnaporthe oryzae  

PubMed Central

Increasing incidences of human disease, crop destruction and ecosystem perturbations are attributable to fungi and threaten socioeconomic progress and food security on a global scale. The blast fungus Magnaporthe oryzae is the most devastating pathogen of cultivated rice, but its metabolic requirements in the host are unclear. Here we report that a purine-requiring mutant of M. oryzae could develop functional appressoria, penetrate host cells and undergo the morphogenetic transition to elaborate bulbous invasive hyphae from primary hyphae, but further in planta growth was aborted. Invasive hyphal growth following rice cell ingress is thus dependent on de novo purine biosynthesis by the pathogen and, moreover, plant sources of purines are neither available to the mutant nor required by the wild type during the early biotrophic phase of infection. This work provides new knowledge about the metabolic interface between fungus and host that might be applicable to other important intracellular fungal pathogens. PMID:23928947

Fernandez, Jessie; Yang, Kuan Ting; Cornwell, Kathryn M.; Wright, Janet D.; Wilson, Richard A.

2013-01-01

427

[Energy flow in arctic aquatic ecosystems  

SciTech Connect

This study is aimed at determining the major pathways of energy flow in freshwater ecosystems of the Alaskan arctic coastal plain. Selected sites for study of the processes supplying energy to streams and lakes to verify the generality of past findings will be surveyed for collection of organisms including the Colville River drainage and the lake region around Teshekpuk Lake. Specific objectives are to collect food web apex organisms (fish and birds) from a variety of sites in the coastal plain to verify descriptive models of ecosystem structure and food web pathways and to compare the utilization rates by insect larvae of fresh litter and in situ primary production relative to more refractory peaty materials through seasonal sampling for isotopic analysis.

Schell, D.M.

1985-12-31

428

Organic carbon hidden in urban ecosystems  

PubMed Central

Urbanization is widely presumed to degrade ecosystem services, but empirical evidence is now challenging these assumptions. We report the first city-wide organic carbon (OC) budget for vegetation and soils, including under impervious surfaces. Urban soil OC storage was significantly greater than in regional agricultural land at equivalent soil depths, however there was no significant difference in storage between soils sampled beneath urban greenspaces and impervious surfaces, at equivalent depths. For a typical U.K. city, total OC storage was 17.6?kg m?2 across the entire urban area (assuming 0?kg m?2 under 15% of land covered by buildings). The majority of OC (82%) was held in soils, with 13% found under impervious surfaces, and 18% stored in vegetation. We reveal that assumptions underpinning current national estimates of ecosystem OC stocks, as required by Kyoto Protocol signatories, are not robust and are likely to have seriously underestimated the contributions of urban areas. PMID:23236585

Edmondson, Jill L.; Davies, Zoe G.; McHugh, Nicola; Gaston, Kevin J.; Leake, Jonathan R.

2012-01-01

429

Toward Understanding, Managing, and Protecting Microbial Ecosystems  

PubMed Central

Microbial communities are at the very basis of life on earth, catalyzing biogeochemical reactions driving global nutrient cycles. However, unlike for plants and animals, microbial diversity is not on the biodiversity–conservation agenda. The latter, however, would imply that microbial diversity is not under any threat by anthropogenic disturbance or climate change. This maybe a misconception caused by the rudimentary knowledge we have concerning microbial diversity and its role in ecosystem functioning. This perspective paper identifies major areas with knowledge gaps within the field of environmental microbiology that preclude a comprehension of microbial ecosystems on the level we have for plants and animals. Opportunities and challenges are pointed out to open the microbial black box and to go from descriptive to predictive microbial ecology. PMID:21747797

Bodelier, Paul L. E.

2011-01-01

430

The 3,000 rice genomes project  

PubMed Central

Background Rice, Oryza sativa L., is the staple food for half the world’s population. By 2030, the production of rice must increase by at least 25% in order to keep up with global population growth and demand. Accelerated genetic gains in rice improvement are needed to mitigate the effects of climate change and loss of arable land, as well as to ensure a stable global food supply. Findings We resequenced a core collection of 3,000 rice accessions from 89 countries. All 3,000 genomes had an average sequencing depth of 14×, with average genome coverages and mapping rates of 94.0% and 92.5%, respectively. From our sequencing efforts, approximately 18.9 million single nucleotide polymorphisms (SNPs) in rice were discovered when aligned to the reference genome of the temperate japonica variety, Nipponbare. Phylogenetic analyses based on SNP data confirmed differentiation of the O. sativa gene pool into 5 varietal groups – indica, aus/boro, basmati/sadri, tropical japonica and temperate japonica. Conclusions Here, we report an international resequencing effort of 3,000 rice genomes. This data serves as a foundation for large-scale discovery of novel alleles for important rice phenotypes using various bioinformatics and/or genetic approaches. It also serves to understand the genomic diversity within O. sativa at a higher level of detail. With the release of the sequencing data, the project calls for the global rice community to take advantage of this data as a foundation for establishing a global, public rice genetic/genomic database and information platform for advancing rice breeding technology for future rice improvement. PMID:24872877

2014-01-01

431

Unique Genotypic Differences Discovered among Indigenous Bangladeshi Rice Landraces  

PubMed Central

Bangladesh is a reservoir of diverse rice germplasm and is home to many landraces with unique, important traits. Molecular characterization of these landraces is of value for their identification, preservation, and potential use in breeding programs. Thirty-eight rice landraces from different regions of Bangladesh including some high yielding BRRI varieties were analyzed by 34 polymorphic microsatellite markers yielding a total of 258 reproducible alleles. The analysis could locate 34 unique identifiers for 21 genotypes, making the latter potentially amenable to identity verification. An identity map for these genotypes was constructed with all the 12 chromosomes of the rice genome. Polymorphism information content (PIC) scores of the 34 SSR markers were 0.098 to 0.89 where on average 7.5 alleles were observed. A dendogram constructed using UPGMA clustered the varieties into two major groups and five subgroups. In some cases, the clustering matched with properties like aromaticity, stickiness, salt tolerance, and photoperiod insensitivity. The results will help breeders to work towards the proper utilization of these landraces for parental selection and linkage map construction for discovery of useful alleles. PMID:25301195

Elias, Sabrina M.; Haque, Taslima; Mahbub Hasan, A. K. M.; Seraj, Zeba I.

2014-01-01

432

Tropical Ecosystem and Soil Development  

E-print Network

nutrient content and ecosystem development #12;How is soil generated from rocks? Weathering #12;SoilTropical Ecosystem and Soil Development Joost van Haren Ecology 596L 09/03/10 #12;Ecosystem biomass strongly dependent on soil Manaus, BDFF plots #12;0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 O ld oxisols

Saleska, Scott

433

Assessing risks to ecosystem quality  

SciTech Connect

Ecosystems are not organisms. Because ecosystems do not reproduce, grow old or sick, and die, the term ecosystem health is somewhat misleading and perhaps should not be used. A more useful concept is ``ecosystem quality,`` which denotes a set of desirable ecosystem characteristics defined in terms of species composition, productivity, size/condition of specific populations, or other measurable properties. The desired quality of an ecosystem may be pristine, as in a nature preserve, or highly altered by man, as in a managed forest or navigational waterway. ``Sustainable development`` implies that human activities that influence ecosystem quality should be managed so that high-quality ecosystems are maintained for future generations. In sustainability-based environmental management, the focus is on maintaining or improving ecosystem quality, not on restricting discharges or requiring particular waste treatment technologies. This approach requires management of chemical impacts to be integrated with management of other sources of stress such as erosion, eutrophication, and direct human exploitation. Environmental scientists must (1) work with decision makers and the public to define ecosystem quality goals, (2) develop corresponding measures of ecosystem quality, (3) diagnose causes for departures from desired states, and (4) recommend appropriate restoration actions, if necessary. Environmental toxicology and chemical risk assessment are necessary for implementing the above framework, but they are clearly not sufficient. This paper reviews the state-of-the science relevant to sustaining the quality of aquatic ecosystems. Using the specific example of a reservoir in eastern Tennessee, the paper attempts to define roles for ecotoxicology and risk assessment in each step of the management process.

Barnthouse, L.W. [Oak Ridge National Lab., TN (United States)

1995-12-31

434

Declining Birds in Grassland Ecosystems  

NSDL National Science Digital Library

This United States Geological Survey (USGS) publication discusses the grassland ecosystem with respect to declining bird species. This report is the effort of a number of agencies to develop a strategy for addressing grassland bird information needs. Grasslands are the most imperiled ecosystem worldwide, and birds associated with this ecosystem are on a decline. This report addresses monitoring issues, species in concern, and the effects of habitat and landscape on grassland birds.

435

THE HYDROLOGIC SYSTEM: GEOMORPHIC AND HYDROGEOLOGIC CONTROLS ON SURFACE AND SUBSURFACE FLOW REGIMES IN RIPARIAN MEADOW ECOSYSTEMS IN THE CENTRAL GREAT BASIN  

EPA Science Inventory

Riparian corridors in upland watersheds in the Great Basin of central Nevada contain the majority of the region's biodiversity. Water, in both surface and subsurface flow regimes, is an important resource sustaining these sensitive ecosystems and other similar riparian ecosystem...

436

Animal Ecosystem Engineers in Streams  

NSDL National Science Digital Library

This peer reviewed article from BioScience is about animal ecosystem engineers in streams. An impressive array of animals function as ecosystem engineers in streams through a variety of activities, ranging from nest digging by anadromous salmon to benthic foraging by South American fishes, from the burrowing of aquatic insects to the trampling of hippos. These ecosystem engineers have local impacts on benthic habitat and also strongly affect downstream fluxes of nutrients and other resources. The impacts of ecosystem engineers are most likely some function of their behavior, size, and population density, modulated by the abiotic conditions of the stream. In streams, subsidies often control the body size and density of ecosystem engineers, while hydrologic energy controls their distribution, density, and life-history attributes, the habitats they create, and the resources and organisms they affect. Because ecosystem engineers can profoundly affect stream ecosystems, and because they themselves can be significantly affected positively or negatively by human activities, understanding ecosystem engineering in streams is increasingly important for the management of these ecosystems.

JONATHAN W. MOORE (;)

2006-03-01

437

PSYCHOLOGY MAJORS --1 PSYCHOLOGY MAJORS --2  

E-print Network

and the world: Developmental Psychology, Social Psy- chology, Cognitive Psychology, Theories of PersonalityPSYCHOLOGY MAJORS -- 1 #12;PSYCHOLOGY MAJORS -- 2 Handbook for Undergraduate Psychology Majors......................................................................................................................................2 A. Psychology Program Goals and Purpose B. Declaration of Major C. History of Marquette University

Sanders, Matthew

438

Problems, Treatment, and Prevention of Paddy Rice Bacterial Disease of Leaf Spot in Kuangtung Province.  

National Technical Information Service (NTIS)

The bacterial paddy rice disease of leaf spot is widespread in Kuangtung Province. The loss in yield of the affected paddies is generally 5-25%, but when the disease is serious, the loss may reach above 30%. One of the major primary source of infection is...

H. Fan

1966-01-01

439

SUPPLEMENTAL ULTRAVIOLET-B RADIATION DOES NOT REDUCE GROWTH OR GRAIN YIELD IN RICE  

EPA Science Inventory

Negative effects of enhanced UV-B radiation have been demonstrated in plants, but impacts under realistic field conditions remain uncertain. Adverse impacts to major crops, such as rice (Oryza sativa L.), that are grown in areas with currently high ambient levels of UV-B, could h...

440

Radiation induced copolymerization of vinyl monomers onto husks and stems of rice cellulose. [Gamma rays  

Microsoft Academic Search

The husks and stems of grain are major products of agricultural processes and have not been very widely used in industry. The present work involves modification of their properties to form potentially useful products. A detailed study on the graft copolymerization of styrene and acrylonitrile on the husks and stems of rice was carried out using a ⁶°Co source as

F. Fazilat; S. H. Rostamie

1978-01-01

441

Radiation-Induced Copolymerization of Vinyl Monomers onto Husk and Stem of Rice Cellulose  

Microsoft Academic Search

The husks and stems of grain comprise major products of agriculture processes and not very widely used in industry. The present study deals with refining such materials to suitable products. A detailed study on the graft copolymerization of styrene and acrylonitrile onto husks and stems of rice cellulose was carried out, a Co-60 source being used as a means of

F. Fazilat; S. H. Rostamie

1979-01-01

442

Involvement of catalase in bacterial Blight disease development of rice caused by Xanthomonas oryzae pv. oryzae  

Microsoft Academic Search

We investigated the role of catalase in determining the virulence of Xanthomonas oryzae pv. oryzae isolates and the reaction of different rice cultivars to virulent isolates. Catalase, being an antioxidant enzyme, plays a major role in combating the toxic effect of reactive oxygen species (ROS) in plant cells. Among the 11 isolates studied, a variable level of catalase activity and

M. S. Choodamani; P. Hariprasad; M. K. Sateesh; S. Umesha

2009-01-01