313 research outputs found

    The Irrigation Efficiency Trap: Rational Farm-Scale Decisions Can Lead to Poor Hydrologic Outcomes at the Basin Scale

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    Agricultural irrigation practices have changed through time as technology has enabled more efficient conveyance and application. In some agricultural regions, irrigation can contribute to incidental aquifer recharge important for groundwater return flows to streams. The Henrys Fork Snake River, Idaho (United States) overlies a portion of the Eastern Snake Plain Aquifer, where irrigated agriculture has occurred for over a century. Using irrigator interviews, aerial and satellite imagery, and statistical streamflow analysis, we document the impact of farm-scale decisions on basin-scale hydrology. Motivated to improve economic efficiency, irrigators began converting from surface to center-pivot sprinkler irrigation in the 1950s, with rapid adoption of center-pivot sprinklers through 2000. Between 1978–2000 and 2001–2022, annual surface-water diversion decreased by 311 Mm3 (23%) and annual return flow to the river decreased by 299 Mm3 over the same period. Some reaches that gained water during 1978–2000 lost water to the aquifer during the later period. We use an interdisciplinary approach to demonstrate how individual farm-scale improvements in irrigation efficiency can cumulatively affect hydrology at the landscape scale and alter groundwater-surface water relationships. Return flows are an important part of basin hydrology in irrigated landscapes and we discuss how managed and incidental aquifer recharge can be implemented to recover return flows to rivers

    Application of Enzymes in Regioselective and Stereoselective Organic Reactions

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    Nowadays, biocatalysts have received much more attention in chemistry regarding their potential to enable high efficiency, high yield, and eco-friendly processes for a myriad of applications. Nature’s vast repository of catalysts has inspired synthetic chemists. Furthermore, the revolutionary technologies in bioengineering have provided the fast discovery and evolution of enzymes that empower chemical synthesis. This article attempts to deliver a comprehensive overview of the last two decades of investigation into enzymatic reactions and highlights the effective performance progress of bio-enzymes exploited in organic synthesis. Based on the types of enzymatic reactions and enzyme commission (E.C.) numbers, the enzymes discussed in the article are classified into oxidoreductases, transferases, hydrolases, and lyases. These applications should provide us with some insight into enzyme design strategies and molecular mechanisms

    RNA-seq transcriptome analysis of male and female zebra finch cell lines

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    AbstractThe derivation of stably cultured cell lines has been critical to the advance of molecular biology. We profiled gene expression in the first two generally available cell lines derived from the zebra finch. Using Illumina RNA-seq, we generated ~93 million reads and mapped the majority to the recently assembled zebra finch genome. Expression of most Ensembl-annotated genes was detected, but over half of the mapped reads aligned outside annotated genes. The male-derived G266 line expressed Z-linked genes at a higher level than did the female-derived ZFTMA line, indicating persistence in culture of the distinctive lack of avian sex chromosome dosage compensation. Although these cell lines were not derived from neural tissue, many neurobiologically relevant genes were expressed, although typically at lower levels than in a reference sample from auditory forebrain. These cell lines recapitulate fundamental songbird biology and will be useful for future studies of songbird gene regulation and function

    The variability of song variability in zebra finch (Taeniopygia guttata) populations

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    Birdsong is a classic example of a learned social behaviour. Song behaviour is also influenced by genetic factors, and understanding the relative contributions of genetic and environmental influences remains a major goal. In this study, we take advantage of captive zebra finch populations to examine variation in a population-level song trait: song variability. Song variability is of particular interest in the context of individual recognition and in terms of the neuro-developmental mechanisms that generate song novelty. We find that the Australian zebra finch Taeniopygia guttata castanotis (TGC) maintains higher song diversity than the Timor zebra finch T. g. guttata (TGG) even after experimentally controlling for early life song exposure, suggesting a genetic basis to this trait. Although wild-derived TGC were intermediate in song variability between domesticated TGC populations and TGG, the difference between domesticated and wild TGC was not statistically significant. The observed variation in song behaviour among zebra finch populations represents a largely untapped opportunity for exploring the mechanisms of social behaviour

    Design considerations in a clinical trial of a cognitive behavioural intervention for the management of low back pain in primary care : Back Skills Training Trial

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    Background Low back pain (LBP) is a major public health problem. Risk factors for the development and persistence of LBP include physical and psychological factors. However, most research activity has focused on physical solutions including manipulation, exercise training and activity promotion. Methods/Design This randomised controlled trial will establish the clinical and cost-effectiveness of a group programme, based on cognitive behavioural principles, for the management of sub-acute and chronic LBP in primary care. Our primary outcomes are disease specific measures of pain and function. Secondary outcomes include back beliefs, generic health related quality of life and resource use. All outcomes are measured over 12 months. Participants randomised to the intervention arm are invited to attend up to six weekly sessions each of 90 minutes; each group has 6–8 participants. A parallel qualitative study will aid the evaluation of the intervention. Discussion In this paper we describe the rationale and design of a randomised evaluation of a group based cognitive behavioural intervention for low back pain

    DNA Methylation Score as a Biomarker in Newborns for Sustained Maternal Smoking during Pregnancy

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    Background: Maternal smoking during pregnancy, especially when sustained, leads to numerous adverse health outcomes in offspring. Pregnant women disproportionately underreport smoking and smokers tend to have lower follow-up rates to repeat questionnaires. Missing, incomplete, or inaccurate data on presence and duration of smoking in pregnancy impairs identification of novel health effects and limits adjustment for smoking in studies of other pregnancy exposures. An objective biomarker in newborns of maternal smoking during pregnancy would be valuable. Objectives: We developed a biomarker of sustained maternal smoking in pregnancy using common DNA methylation platforms. Methods: Using a dimension reduction method, we developed and tested a numeric score in newborns to reflect sustained maternal smoking in pregnancy from data on cotinine, a short-term smoking biomarker measured mid-pregnancy, and Illumina450K cord blood DNA methylation from newborns in the Norwegian Mother and Child Cohort Study (MoBa). Results: This score reliably predicted smoking status in the training set (n = 1,057; accuracy = 96%, sensitivity = 80%, specificity = 98%). Sensitivity (58%) was predictably lower in the much smaller test set (n = 221), but accuracy (91%) and specificity (97%) remained high. Reduced birth weight, a well-known effect of maternal smoking, was as strongly related to the score as to cotinine. A three-site score had lower, but acceptable, performance (accuracytrain = 82%, accuracytest = 83%). Conclusions: Our smoking methylation score represents a promising novel biomarker of sustained maternal smoking during pregnancy easily calculated with Illumina450K or IlluminaEPIC data. It may help identify novel health impacts and improve adjustment for smoking when studying other risk factors with more subtle effects.publishedVersio

    Comparing the Consistency of Atom Probe Tomography Measurements of Small-Scale Segregation and Clustering between the LEAP 3000 and LEAP 5000 Instruments

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    The local electrode atom probe (LEAP) has become the primary instrument used for atom probe tomography measurements. Recent advances in detector and laser design, together with updated hit detection algorithms, have been incorporated into the latest LEAP 5000 instrument, but the implications of these changes on measurements, particularly the size and chemistry of small clusters and elemental segregations, have not been explored. In this study, we compare data sets from a variety of materials with small-scale chemical heterogeneity using both a LEAP 3000 instrument with 37% detector efficiency and a 532-nm green laser and a new LEAP 5000 instrument with a manufacturer estimated increase to 52% detector efficiency, and a 355-nm ultraviolet laser. In general, it was found that the number of atoms within small clusters or surface segregation increased in the LEAP 5000, as would be expected by the reported increase in detector efficiency from the LEAP 3000 architecture, but subtle differences in chemistry were observed which are attributed to changes in the way multiple hit detection is calculated using the LEAP 5000

    Genomic and neural analysis of the estradiol-synthetic pathway in the zebra finch

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    <p>Abstract</p> <p>Background</p> <p>Steroids are small molecule hormones derived from cholesterol. Steroids affect many tissues, including the brain. In the zebra finch, estrogenic steroids are particularly interesting because they masculinize the neural circuit that controls singing and their synthesis in the brain is modulated by experience. Here, we analyzed the zebra finch genome assembly to assess the content, conservation, and organization of genes that code for components of the estrogen-synthetic pathway and steroid nuclear receptors. Based on these analyses, we also investigated neural expression of a cholesterol transport protein gene in the context of song neurobiology.</p> <p>Results</p> <p>We present sequence-based analysis of twenty steroid-related genes using the genome assembly and other resources. Generally, zebra finch genes showed high homology to genes in other species. The diversity of steroidogenic enzymes and receptors may be lower in songbirds than in mammals; we were unable to identify all known mammalian isoforms of the 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase families in the zebra finch genome assembly, and not all splice sites described in mammals were identified in the corresponding zebra finch genes. We did identify two factors, Nobox and NR1H2-RXR, that may be important for coordinated transcription of multiple steroid-related genes. We found very little qualitative overlap in predicted transcription factor binding sites in the genes for two cholesterol transport proteins, the 18 kDa cholesterol transport protein (TSPO) and steroidogenic acute regulatory protein (StAR). We therefore performed in situ hybridization for TSPO and found that its mRNA was not always detected in brain regions where StAR and steroidogenic enzymes were previously shown to be expressed. Also, transcription of TSPO, but not StAR, may be regulated by the experience of hearing song.</p> <p>Conclusions</p> <p>The genes required for estradiol synthesis and action are represented in the zebra finch genome assembly, though the complement of steroidogenic genes may be smaller in birds than in mammals. Coordinated transcription of multiple steroidogenic genes is possible, but results were inconsistent with the hypothesis that StAR and TSPO mRNAs are co-regulated. Integration of genomic and neuroanatomical analyses will continue to provide insights into the evolution and function of steroidogenesis in the songbird brain.</p
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