932 research outputs found

    Advances in the identification of novel factors required in soybean nodulation, a process critical to sustainable agriculture and food security

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    Nodulation is a process of organogenesis that results from a symbiotic relationship between legume plants and soil-dwelling, nitrogen-fixing bacteria, called rhizobia. The rhizobia are housed in newly formed structures on the host roots, called nodules. Within nodules, the rhizobia fix atmospheric N2 into useable forms of nitrogen for the plant. This process is highly important to agriculture, as nitrogen is critical for plant growth and development and is typically the main component of fertilizers. Although fertilizers are effective, they are expensive and often pollute, making biological alternatives, such as legume nodulation, attractive for use in agriculture. Nodulation is regulated by the auto regulation of nodulation (AON) pathway, which enables the host plant to balance its needs between nitrogen acquisition and energy expenditure. Current research is elucidating the nodule development and AON signalling networks. Recent technological advances, such as RNA-sequencing, are revolutionizing the discovery of genes that are critical to nodulation. The discovery of such genes not only enhances our knowledge of the nodulation signalling network, but may help to underpin future work to isolate superior legume crops via modern breeding and engineering practices. Here, recent advances using the cutting-edge technique of RNA sequencing to identify new nodulation genes in soybean are discussed

    Integrasi Bahasa Inggris ke Bahasa Indonesia Berbasis Media Komunikasi Elektronik Komputer.

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    This study has two purposes. (1) Describe the design of the development model of English integration theory into Indonesian based on electronic computer communication media. (2) To describe factors causing the integration of English into Indonesian based on electronic computer communication media. This study used descriptive qualitative method. The data in this research is a word that contains the integration of English into Indonesian based electronic communication media computer. Data collection techniques in this study is the method refer and the method of record. The method of referring to the use of language in the computer electronic communication media to identify data about the integration of English into Indonesian language. Record technique used by researchers to record data in the form of words that contain integration of English into Indonesian language based on computer communication media. The results of this study indicate that the design of the development model of English integration theory into Indonesian based electronic computer communication media is grouped into two processes. (1) direct translation and (2) interpretation of concepts. Factors causing the integration of English into Indonesian-based electronic computer communication media is due to (1) the speaker's bilingualism and (2) the development of Science and Technology. Keywords: integration, electronic computer communication media

    Maternal circulating leukocytes display early chemotactic responsiveness during late gestation

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    Abstract Background Parturition has been widely described as an immunological response; however, it is unknown how this is triggered. We hypothesized that an early event in parturition is an increased responsiveness of peripheral leukocytes to chemotactic stimuli expressed by reproductive tissues, and this precedes expression of tissue chemotactic activity, uterine activation and the systemic progesterone/estradiol shift. Methods Tissues and blood were collected from pregnant Long-Evans rats on gestational days (GD) 17, 20 and 22 (term gestation). We employed a validated Boyden chamber assay, flow cytometry, quantitative real time-polymerase chain reaction, and enzyme-linked immunosorbent assays. Results We found that GD20 maternal peripheral leukocytes migrated more than those from GD17 when these were tested with GD22 uterus and cervix extracts. Leukocytes on GD20 also displayed a significant increase in chemokine (C-C motif) ligand 2 (Ccl2) gene expression and this correlated with an increase in peripheral granulocyte proportions and a decrease in B cell and monocyte proportions. Tissue chemotactic activity and specific chemokines (CCL2, chemokine (C-X-C motif) ligand 1/CXCL1, and CXCL10) were mostly unchanged from GD17 to GD20 and increased only on GD22. CXCL10 peaked on GD20 in cervical tissues. As expected, prostaglandin F2α receptor and oxytocin receptor gene expression increased dramatically between GD20 and 22. Progesterone concentrations fell and estradiol-17β concentrations increased in peripheral serum, cervical and uterine tissue extracts between GD20 and 22. Conclusion Maternal circulating leukocytes display early chemotactic responsiveness, which leads to their infiltration into the uterus where they may participate in the process of parturition

    Age-related mitochondrial DNA depletion and the impact on pancreatic beta cell function

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    Type 2 diabetes is characterised by an age-related decline in insulin secretion. We previously identified a 50% age-related decline in mitochondrial DNA (mtDNA) copy number in isolated human islets. The purpose of this study was to mimic this degree of mtDNA depletion in MIN6 cells to determine whether there is a direct impact on insulin secretion. Transcriptional silencing of mitochondrial transcription factor A, TFAM, decreased mtDNA levels by 40% in MIN6 cells. This level of mtDNA depletion significantly decreased mtDNA gene transcription and translation, resulting in reduced mitochondrial respiratory capacity and ATP production. Glucose-stimulated insulin secretion was impaired following partial mtDNA depletion, but was normalised following treatment with glibenclamide. This confirms that the deficit in the insulin secretory pathway precedes K+ channel closure, indicating that the impact of mtDNA depletion is at the level of mitochondrial respiration. In conclusion, partial mtDNA depletion to a degree comparable to that seen in aged human islets impaired mitochondrial function and directly decreased insulin secretion. Using our model of partial mtDNA depletion following targeted gene silencing of TFAM, we have managed to mimic the degree of mtDNA depletion observed in aged human islets, and have shown how this correlates with impaired insulin secretion. We therefore predict that the age-related mtDNA depletion in human islets is not simply a biomarker of the aging process, but will contribute to the age-related risk of type 2 diabetes

    Magnetic Ordering in V-Layers of the Superconducting System of Sr2VFeAsO3

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    Results of transport, magnetic, thermal, and 75As-NMR measurements are presented for superconducting Sr2VFeAsO3 with an alternating stack of FeAs and perovskite-like block layers. Although apparent anomalies in magnetic and thermal properties have been observed at ~150 K, no anomaly in transport behaviors has been observed at around the same temperature. These results indicate that V ions in the Sr2VO3-block layers have localized magnetic moments and that V-electrons do not contribute to the Fermi surface. The electronic characteristics of Sr2VFeAsO3 are considered to be common to those of other superconducting systems with Fe-pnictogen layers.Comment: 4 pages, 4 figures, To appear in JPSJ 79 (2010) 12371

    Fitness versus Fatness and Insulin Resistance in U.S. Adolescents

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    Background. The present study examined the relationship between insulin resistance and both waist circumference and cardiorespiratory fitness in U.S. adolescents. Methods. NHANES assessed a nationally representative sample of U.S. adolescents (12–18 yrs) between 1999–2002. Abdominal adiposity was estimated by waist circumference, overall adiposity by BMI, and cardiorespiratory fitness (maximal oxygen uptake (VO2max) from a treadmill exercise test). Insulin resistance was estimated from fasting insulin and glucose using the homeostatic model assessment method (i.e., HOMA) and was log-transformed. Results. 1078 adolescents were included in the study. Positive correlations existed between lnHOMA and waist circumference (r = 0.59; r = 0.54) for boys and girls, respectively. lnHOMA and VO2max were inversely related in boys (r = −0.29) but not girls (r = −0.06). Gender-specific analyses by BMI category showed that the significant inverse relationship in lnHOMA and VO2max was primarily present in obese boys. Conclusion. Among adolescents, important gender and BMI differences exist in the relationship between insulin resistance and fitness. While waist circumference and BMI are important predictors in all children, fitness appears especially important in obese boys. These findings may have important implications for gender-specific interventions to prevent adult obesity and diabetes mellitus

    Exploring the source of TYLCV resistance in Nicotiana benthamiana

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    Tomato Yellow Leaf Curl Virus (TYLCV) is one of the most devastating pathogens of tomato, worldwide. It is vectored by the globally prevalent whitefly, Bemisia tabaci, and is asymptomatic in a wide range of plant species that act as a virus reservoir. The most successful crop protection for tomato in the field has been from resistance genes, of which five loci have been introgressed fromwild relatives. Of these, the Ty-1/Ty-3 locus, which encodes an RNA-dependent RNA polymerase 3 (RDR3), has been the most effective. Nevertheless, several TYLCV strains that break this resistance are beginning to emerge, increasing the need for new sources of resistance. Here we use segregation analysis and CRISPR-mediated gene dysfunctionalisation to dissect the differential response of two isolates of Nicotiana benthamiana to TYLCV infection. Our study indicates the presence of a novel non-RDR3, but yet to be identified, TYLCV resistance gene in a wild accession of N. benthamiana. This gene has the potential to be incorporated into tomatoes
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