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991.
992.
Ratnam Wickneswari M. A. R. Bhuiyan Sabu Kalluvettankuzhy K. Li Sze Lim Michael J. Thomson Md. Kairudin Narimah Md. Zain Abdullah 《Plant Molecular Biology Reporter》2012,30(4):929-939
A backcross breeding strategy was used to identify quantitative trait loci (QTLs) associated with 14 traits in a BC2F2 population derived from a cross between MR219, an indica rice cultivar and an accession of Oryza rufipogon (IRGC 105491). A total of 261 lines were genotyped with 96 microsatellite markers and evaluated for plant morphology, yield components and growth period. The genetic linkage map generated for this population with an average interval size of 16.2?cM, spanning 1,553.4?cM (Kosambi) of the rice genome. Thirty-eight QTLs were identified with composite interval mapping (CIM), whereas simple interval mapping (SIM) resulted in 47 QTLs (LOD >3.0). The O. rufipogon allele was favourable for 59% of QTLs detected through CIM. Of 261 BC2F2 families, 26 advanced backcross breeding lines (BC2F5) were used for QTL validation. These lines were selected on the basis of the yield traits potentiality in BC2F3 and BC2F4 generations. The field trial was conducted at three different locations in Malaysia using randomized complete block design with three replications. Trait based marker analysis was done for QTL determination. Twenty-five QTLs were detected in BC2F5 generation whereas 29 QTLs were detected in BC2F2 generation of the same population. Two QTLs (qPL-1 and qSPL-7) were not considered for validation due to their low R 2 values and two QTLs (qPSS-3-2 and qGW-3-2) were not detected in the BC2F5 population. Fifteen QTLs showed the beneficial effect to enhance the trait value of the breeding lines. QTL validation aided to select the promising lines for further utilization. 相似文献
993.
On the performance of adaptive preprocessing technique in analyzing high‐dimensional censored data 下载免费PDF全文
Md Hasinur Rahaman Khan 《Biometrical journal. Biometrische Zeitschrift》2018,60(4):687-702
Preprocessing for high‐dimensional censored datasets, such as the microarray data, is generally considered as an important technique to gain further stability by reducing potential noise from the data. When variable selection including inference is carried out with high‐dimensional censored data the objective is to obtain a smaller subset of variables and then perform the inferential analysis using model estimates based on the selected subset of variables. This two stage inferential analysis is prone to circularity bias because of the noise that might still remain in the dataset. In this work, I propose an adaptive preprocessing technique that uses sure independence screening (SIS) idea to accomplish variable selection and reduces the circularity bias by some popularly known refined high‐dimensional methods such as the elastic net, adaptive elastic net, weighted elastic net, elastic net‐AFT, and two greedy variable selection methods known as TCS, PC‐simple all implemented with the accelerated lifetime models. The proposed technique addresses several features including the issue of collinearity between important and some unimportant covariates, which is often the case in high‐dimensional setting under variable selection framework, and different level of censoring. Simulation studies along with an empirical analysis with a real microarray data, mantle cell lymphoma, is carried out to demonstrate the performance of the adaptive pre‐processing technique. 相似文献
994.
Kay O. Johswich Shannon E. McCaw Epshita Islam Anna Sintsova Angel Gu John E. Shively Scott D. Gray-Owen 《PLoS pathogens》2013,9(7)
Neisseria meningitidis (Nme) asymptomatically colonizes the human nasopharynx, yet can initiate rapidly-progressing sepsis and meningitis in rare instances. Understanding the meningococcal lifestyle within the nasopharyngeal mucosa, a phase of infection that is prerequisite for disease, has been hampered by the lack of animal models. Herein, we compare mice expressing the four different human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) that can bind the neisserial Opa protein adhesins, and find that expression of human CEACAM1 is necessary and sufficient to establish intranasal colonization. During infection, in vivo selection for phase variants expressing CEACAM1-specific Opa proteins occurs, allowing mucosal attachment and entry into the subepithelial space. Consistent with an essential role for Opa proteins in this process, Opa-deficient meningococci were unable to colonize the CEACAM1-humanized mice. While simple Opa-mediated attachment triggered an innate response regardless of meningococcal viability within the inoculum, persistence of viable Opa-expressing bacteria within the CEACAM1-humanized mice was required for a protective memory response to be achieved. Parenteral immunization with a capsule-based conjugate vaccine led to the accumulation of protective levels of Nme-specific IgG within the nasal mucus, yet the sterilizing immunity afforded by natural colonization was instead conferred by Nme-specific IgA without detectable IgG. Considered together, this study establishes that the availability of CEACAM1 helps define the exquisite host specificity of this human-restricted pathogen, displays a striking example of in vivo selection for the expression of desirable Opa variants, and provides a novel model in which to consider meningococcal infection and immunity within the nasopharyngeal mucosa. 相似文献
995.
Benter IF Juggi JS Khan I Yousif MH Canatan H Akhtar S 《Molecular and cellular biochemistry》2005,268(1-2):175-183
It is well established that brief episodes of ischemia/reperfusion (I/R) [preconditioning (PC)] protect the myocardium from the damage induced by subsequent more prolonged I/R. However, the signaling pathways activated during PC or I/R are not well characterized. In this study, the role of Ras-GTPase, tyrosine kinases (TKs), epidermal growth factor receptor (EGFR) and Ca2 +/calmodulin-dependent protein kinase II (CaMK II) in mediating PC in a perfused rat heart model was investigated. A 40-min episode of global ischemia in perfused rat hearts produced significantly impaired cardiac function, measured as left ventricular developed pressure (Pmax) and left ventricular end-diastolic pressure (LVEDP), and impaired coronary hemodynamics, measured as coronary flow (CF) and coronary vascular resistance (CVR). PC significantly enhanced cardiac recovery after I/R. Combination of PC and FPT III (Ras-GTPase inhibitor FPT III; 232 ng/min for 6 days) treatment did not produce any additive benefits as compared to PC alone. In contrast, PC-induced improvements in cardiac function after I/R were significantly attenuated by pretreatment with genistein (1mg/kg/day for 6 days), a broad-spectrum inhibitor of TKs, or AG1478 (1mg/kg/day for 6 days), a specific inhibitor of EGFR tyrosine kinase or KN-93 (578 ng/min for 6 days), a CaMK II inhibitor, before PC. These observations suggest that PC and FPT III pretreatment may produce cardioprotection via similar mechanisms. Present results also indicate that activation of TKs and specifically activation of EGFR-mediated TKs and CaMK II-mediated regulation of calcium homeostasis are part of the PC mechanisms that improve recovery after I/R. (Mol Cell Biochem 268: 175–183, 2005) 相似文献
996.
Validity of the Remote Food Photography Method Against Doubly Labeled Water Among Minority Preschoolers 下载免费PDF全文
997.
Quynh NT Islam MS Islam SM Florén A Bartfai T Langel U Ostenson CG 《Biochemical and biophysical research communications》2005,328(1):213-220
Galanin is a neurotransmitter peptide that suppresses insulin secretion. The present study aimed at investigating how a non-peptide galanin receptor agonist, galnon, affects insulin secretion from isolated pancreatic islets of healthy Wistar and diabetic Goto-Kakizaki (GK) rats. Galnon stimulated insulin release potently in isolated Wistar rat islets; 100 microM of the compound increased the release 8.5 times (p<0.001) at 3.3 mM and 3.7 times (p<0.001) at 16.7 mM glucose. Also in islet perifusions, galnon augmented several-fold both acute and late phases of insulin response to glucose. Furthermore, galnon stimulated insulin release in GK rat islets. These effects were not inhibited by the presence of galanin or the galanin receptor antagonist M35. The stimulatory effects of galnon were partly inhibited by the PKA and PKC inhibitors, H-89 and calphostin C, respectively, at 16.7 but not 3.3 mM glucose. In both Wistar and GK rat islets, insulin release was stimulated by depolarization of 30 mM KCl, and 100 microM galnon further enhanced insulin release 1.5-2 times (p<0.05). Cytosolic calcium levels, determined by fura-2, were increased in parallel with insulin release, and the L-type Ca2+-channel blocker nimodipine suppressed insulin response to glucose and galnon. In conclusion, galnon stimulates insulin release in islets of healthy rats and diabetic GK rats. The mechanism of this stimulatory effect does not involve galanin receptors. Galnon-induced insulin release is not glucose-dependent and appears to involve opening of L-type Ca2+-channels, but the main effect of galnon seems to be exerted at a step distal to these channels, i.e., at B-cell exocytosis. 相似文献
998.
999.
One of the major impacts of climate change has been the marked rise in global temperature. Recently, we demonstrated that high temperatures (1-week exposure) disrupt prooxidant-antioxidant homeostasis and promote cellular apoptosis in the American oyster. In this study, we evaluated the effects of seasonal sea surface temperature (SST) on tissue morphology, extrapallial fluid (EPF) conditions, heat shock protein-70 (HSP70), dinitrophenyl protein (DNP, an indicator of reactive oxygen species, ROS), 3-nitrotyrosine protein (NTP, an indicator of RNS), catalase (CAT), superoxide dismutase (SOD) protein expressions, and cellular apoptosis in gills and digestive glands of oysters collected on the southern Texas coast during the winter (15 °C), spring (24 °C), summer (30 °C), and fall (27 °C). Histological observations of both tissues showed a notable increase in mucus production and an enlargement of the digestive gland lumen with seasonal temperature rise, whereas biochemical analyses exhibited a significant decrease in EPF pH and protein concentration. Immunohistochemical analyses showed higher expression of HSP70 along with the expression of DNP and NTP in oyster tissues during summer. Intriguingly, CAT and SOD protein expressions exhibited significant upregulation with rising seasonal temperatures (15 to 27 °C), which decreased significantly in summer (30 °C), leaving oysters vulnerable to oxidative and nitrative damage. qRT-PCR analysis revealed a significant increase in HSP70 mRNA levels in oyster tissues during the warmer seasons. In situ TUNNEL assay showed a significant increase in apoptotic cells in seasons with high temperature. These results suggest that elevated SST induces oxidative/nitrative stress through the overproduction of ROS/RNS and disrupts the antioxidant system which promotes cellular apoptosis in oysters.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12192-021-01232-2. 相似文献
1000.
The discovery of natural and natural-based compounds has resulted in its application as an alternative to synthetic algicides to control harmful algae in aquatic systems. Of the many natural-product-based algicides, sorgoleone, a natural plant product from Sorghum bicolor root exudates has been investigated for its controlling effect on different algal species and its acute fish toxicity. Growth of the blue green algal species Microcystis aeruginosa Kützing was completely inhibited by the crude methanol extract of sorghum root at 20 μg mL−1. The most noticeable inhibition was observed in the bioassay of n-hexane soluble extract, where 98% growth inhibition occurred in M. aeruginosa at the concentration of 1.25 μg mL−1. Sorgoleone very effectively controlled blue green algae inhibiting 97% of M. aeruginosa at 0.5 μg mL−1 and 99% of Anabaena affinis Lemmermann at 4 μg mL−1. In contrast, inhibition of the green algae species Chlorella vulgaris Beijerinck and Scenedensmus spp. at 16 μg mL−1 sorgoleone was 87 and 68%, respectively. There were no mortalities or adverse effects observed in any of the fish exposed to water control, solvent control, and a nominal concentration of 1 μg mL−1 during the test period. The no observed effect concentration (NOEC) value was 1.5 μg mL−1 for the tested fish (O. latipes). Sorgoleone can be considered as an effective and an ecologically and environmentally sustainable approach to controlling harmful algae. 相似文献