70 research outputs found

    MOLECULAR BIOLOGY AND PHYSIOLOGY Genotypic Variation in Physiological Strategies For Attaining Cotton Lint Yield Production

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    ABSTRACT The quality and quantity of cotton (Gossypium hirsutum L.) lint produced are complex traits controlled by multiple processes. The physiology behind yield and quality variations is not completely understood. Objectives for this research were to document the physiological strategies diverse cotton genotypes take to achieve their yield and fiber quality. The genotypes 'DPL 444BR', 'DPL 555BR', 'FM 800BR', 'MD 9', 'MD 15-OP', 'MD 29', 'MD 51 normal', 'MD 51 okra', 'PM 1218BR', and 'ST 4892BR' were grown in the field from 2005-2008. Dry matter partitioning, leaf photosynthesis, chlorophyll concentration, root hydraulic conductance, lint yield, yield components, and fiber quality data were collected. Lint yields ranged from 1675 to 1119 kg ha -1 among the genotypes. The size of the available carbon assimilate pool generated by a genotype appeared to be related to lint yield production. Genotypes used different strategies to generate this carbon assimilate pool, i.e. through improved photosynthetic rates and/ or solar radiation interception, and then convert that carbon into lint production. Fiber quality variations, however, could not easily be explained by just variations in the plants ability to produce carbon assimilates. Beyond just the quantity of carbon assimilates, it is the manner in which the plant assembles these carbon skeletons into the cellular matrix that determines the quality of the fiber produced. These research findings can be utilized to meet the challenge of future yield and fiber quality improvements

    MOLECULAR BIOLOGY AND PHYSIOLOGY Genotypic Variation in Physiological Strategies For Attaining Cotton Lint Yield Production

    Get PDF
    ABSTRACT The quality and quantity of cotton (Gossypium hirsutum L.) lint produced are complex traits controlled by multiple processes. The physiology behind yield and quality variations is not completely understood. Objectives for this research were to document the physiological strategies diverse cotton genotypes take to achieve their yield and fiber quality. The genotypes 'DPL 444BR', 'DPL 555BR', 'FM 800BR', 'MD 9', 'MD 15-OP', 'MD 29', 'MD 51 normal', 'MD 51 okra', 'PM 1218BR', and 'ST 4892BR' were grown in the field from 2005-2008. Dry matter partitioning, leaf photosynthesis, chlorophyll concentration, root hydraulic conductance, lint yield, yield components, and fiber quality data were collected. Lint yields ranged from 1675 to 1119 kg ha -1 among the genotypes. The size of the available carbon assimilate pool generated by a genotype appeared to be related to lint yield production. Genotypes used different strategies to generate this carbon assimilate pool, i.e. through improved photosynthetic rates and/ or solar radiation interception, and then convert that carbon into lint production. Fiber quality variations, however, could not easily be explained by just variations in the plants ability to produce carbon assimilates. Beyond just the quantity of carbon assimilates, it is the manner in which the plant assembles these carbon skeletons into the cellular matrix that determines the quality of the fiber produced. These research findings can be utilized to meet the challenge of future yield and fiber quality improvements

    The association of urinary cadmium with sex steroid hormone concentrations in a general population sample of US adult men

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    <p>Abstract</p> <p>Background</p> <p>Studies investigating the association of cadmium and sex steroid hormones in men have been inconsistent, but previous studies were relatively small.</p> <p>Methods</p> <p>In a nationally representative sample of 1,262 men participating in the morning examination session of phase I (1998–1991) of the third National Health and Nutrition Examination Survey, creatinine corrected urinary cadmium and serum concentrations of sex steroid hormones were measured following a standardized protocol.</p> <p>Results</p> <p>After adjustment for age and race-ethnicity, higher cadmium levels were associated with higher levels of total testosterone, total estradiol, sex hormone-binding globulin, estimated free testosterone, and estimated free estradiol (each p-trend < 0.05). After additionally adjusting for smoking status and serum cotinine, none of the hormones maintained an association with urinary cadmium (each p-trend > 0.05).</p> <p>Conclusion</p> <p>Urinary cadmium levels were not associated with sex steroid hormone concentrations in a large nationally representative sample of US men.</p

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    A multi-stage genome-wide association study of bladder cancer identifies multiple susceptibility loci.

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    We conducted a multi-stage, genome-wide association study of bladder cancer with a primary scan of 591,637 SNPs in 3,532 affected individuals (cases) and 5,120 controls of European descent from five studies followed by a replication strategy, which included 8,382 cases and 48,275 controls from 16 studies. In a combined analysis, we identified three new regions associated with bladder cancer on chromosomes 22q13.1, 19q12 and 2q37.1: rs1014971, (P = 8 × 10⁻¹²) maps to a non-genic region of chromosome 22q13.1, rs8102137 (P = 2 × 10⁻¹¹) on 19q12 maps to CCNE1 and rs11892031 (P = 1 × 10⁻⁷) maps to the UGT1A cluster on 2q37.1. We confirmed four previously identified genome-wide associations on chromosomes 3q28, 4p16.3, 8q24.21 and 8q24.3, validated previous candidate associations for the GSTM1 deletion (P = 4 × 10⁻¹¹) and a tag SNP for NAT2 acetylation status (P = 4 × 10⁻¹¹), and found interactions with smoking in both regions. Our findings on common variants associated with bladder cancer risk should provide new insights into the mechanisms of carcinogenesis

    Tracking down carbon inputs underground from an arid zone Australian calcrete.

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    Freshwater ecosystems play a key role in shaping the global carbon cycle and maintaining the ecological balance that sustains biodiversity worldwide. Surficial water bodies are often interconnected with groundwater, forming a physical continuum, and their interaction has been reported as a crucial driver for organic matter (OM) inputs in groundwater systems. However, despite the growing concerns related to increasing anthropogenic pressure and effects of global change to groundwater environments, our understanding of the dynamics regulating subterranean carbon flows is still sparse. We traced carbon composition and transformations in an arid zone calcrete aquifer using a novel multidisciplinary approach that combined isotopic analyses of dissolved organic carbon (DOC) and inorganic carbon (DIC) (δ13CDOC, δ13CDIC, 14CDOC and 14CDIC) with fluorescence spectroscopy (Chromophoric Dissolved OM (CDOM) characterisation) and metabarcoding analyses (taxonomic and functional genomics on bacterial 16S rRNA). To compare dynamics linked to potential aquifer recharge processes, water samples were collected from two boreholes under contrasting rainfall: low rainfall ((LR), dry season) and high rainfall ((HR), wet season). Our isotopic results indicate limited changes and dominance of modern terrestrial carbon in the upper part (northeast) of the bore field, but correlation between HR and increased old and 13C-enriched DOC in the lower area (southwest). CDOM results show a shift from terrestrially to microbially derived compounds after rainfall in the same lower field bore, which was also sampled for microbial genetics. Functional genomic results showed increased genes coding for degradative pathways-dominated by those related to aromatic compound metabolisms-during HR. Our results indicate that rainfall leads to different responses in different parts of the bore field, with an increase in old carbon sources and microbial processing in the lower part of the field. We hypothesise that this may be due to increasing salinity, either due to mobilisation of Cl- from the soil, or infiltration from the downstream salt lake during HR. This study is the first to use a multi-technique assessment using stable and radioactive isotopes together with functional genomics to probe the principal organic biogeochemical pathways regulating an arid zone calcrete system. Further investigations involving extensive sampling from diverse groundwater ecosystems will allow better understanding of the microbiological pathways sustaining the ecological functioning of subterranean biota
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