529 research outputs found

    OPTIMAL CROP INSURANCE OPTIONS FOR ALABAMA COTTON-PEANUT PRODUCERS: A TARGET-MOTAD ANALYSIS

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    Target-MOTAD was used to determine the optimal crop insurance options for two representative cotton and peanut farms in southern Alabama. Results showed that, for one of the farms, no crop insurance option was risk reducing given the yield history. For the other farm, risk reduction involved shifting to higher levels of insurance coverage.Risk and Uncertainty,

    Comparative genomics of the Hedgehog loci in chordates and the origins of Shh regulatory novelties

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    The origin and evolution of the complex regulatory landscapes of some vertebrate developmental genes, often spanning hundreds of Kbp and including neighboring genes, remain poorly understood. The Sonic Hedgehog (Shh) genomic regulatory block (GRB) is one of the best functionally characterized examples, with several discrete enhancers reported within its introns, vast upstream gene-free region and neighboring genes (Lmbr1 and Rnf32). To investigate the origin and evolution of this GRB, we sequenced and characterized the Hedgehog (Hh) loci from three invertebrate chordate amphioxus species, which share several early expression domains with Shh. Using phylogenetic footprinting within and between chordate lineages, and reporter assays in zebrafish probing >30 Kbp of amphioxus Hh, we report large sequence and functional divergence between both groups. In addition, we show that the linkage of Shh to Lmbr1 and Rnf32, necessary for the unique gnatostomate-specific Shh limb expression, is a vertebrate novelty occurred between the two whole-genome duplications

    Proresolving and cartilage-protective actions of resolvin D1 in inflammatory arthritis

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    Rheumatoid arthritis (RA) is a debilitating disease characterized by persistent accumulation of leukocytes within the articular cavity and synovial tissue. Metabololipidomic profiling of arthritic joints from omega-3 supplemented mice identified elevated levels of specialized proresolving lipid mediators (SPM) including resolvin D1 (RvD1). Profiling of human RA synovial fluid revealed physiological levels of RvD1, which - once applied to human neutrophils - attenuated chemotaxis. These results prompted analyses of the antiarthritic properties of RvD1 in a model of murine inflammatory arthritis. The stable epimer 17R-RvD1 (100 ng/day) significantly attenuated arthritis severity, cachexia, hind-paw edema, and paw leukocyte infiltration and shortened the remission interval. Metabololipidomic profiling in arthritic joints revealed 17R-RvD1 significantly reduced PGE2 biosynthesis, while increasing levels of protective SPM. Molecular analyses indicated that 17R-RvD1 enhanced expression of genes associated with cartilage matrix synthesis, and direct intraarticular treatment induced chondroprotection. Joint protective actions of 17R-RvD1 were abolished in RvD1 receptor-deficient mice termed ALX/fpr2/3-/- . These investigations open new therapeutic avenues for inflammatory joint diseases, providing mechanistic substance for the benefits of omega-3 supplementation in RA

    Directional memory arises from long-lived cytoskeletal asymmetries in polarized chemotactic cells

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    Chemotaxis, the directional migration of cells in a chemical gradient, is robust to fluctuations associated with low chemical concentrations and dynamically changing gradients as well as high saturating chemical concentrations. Although a number of reports have identified cellular behavior consistent with a directional memory that could account for behavior in these complex environments, the quantitative and molecular details of such a memory process remain unknown. Using microfluidics to confine cellular motion to a 1D channel and control chemoattractant exposure, we observed directional memory in chemotactic neutrophil-like cells. We modeled this directional memory as a long-lived intracellular asymmetry that decays slower than observed membrane phospholipid signaling. Measurements of intracellular dynamics revealed that moesin at the cell rear is a long-lived element that when inhibited, results in a reduction of memory. Inhibition of ROCK (Rho-associated protein kinase), downstream of RhoA (Ras homolog gene family, member A), stabilized moesin and directional memory while depolymerization of microtubules (MTs) disoriented moesin deposition and also reduced directional memory. Our study reveals that long-lived polarized cytoskeletal structures, specifically moesin, actomyosin, and MTs, provide a directional memory in neutrophil-like cells even as they respond on short time scales to external chemical cues

    Biomagnetic signatures of uncoupled gastric musculature

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    Gastric slow waves propagate in the electrical syncytium of the healthy stomach, being generated at a rate of approximately three times per minute in a pacemaker region along the greater curvature of the antrum and propagating distally towards the pylorus. Disease states are known to alter the normal gastric slow wave. Recent studies have suggested the use of biomagnetic techniques for assessing parameters of the gastric slow wave that have potential diagnostic significance. We present a study in which the gastric syncytium was uncoupled by mechanical division as we recorded serosal electric potentials along with multichannel biomagnetic signals and cutaneous potentials. By computing the surface current density (SCD) from multichannel biomagnetic recordings, we were able to quantify gastric slow wave propagation as well as the frequency and amplitude of the slow wave and to show that these correlate well with similar parameters from serosal electrodes. We found the dominant slow wave frequency to be an unreliable indicator of gastric uncoupling as uncoupling results in the appearance of multiple slow wave sources at various frequencies in external recordings. The percentage of power distributed in specific frequency ranges exhibited significant postdivision changes. Propagation velocity determined from SCD maps was a weak indicator of uncoupling in this work; we believe that the relatively low spatial resolution of our 19-channel biomagnetometer confounds the characterization of spatial variations in slow wave propagation velocities. Nonetheless, the biomagnetic technique represents a non-invasive method for accurate determination of clinically significant parameters of the gastric slow wave

    Pleiotropic contribution of rbfox1 to psychiatric and neurodevelopmental phenotypes in two zebrafish models

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    RBFOX1 is a highly pleiotropic gene that contributes to several psychiatric and neurodevelopmental disorders. Both rare and common variants in RBFOX1 have been associated with several psychiatric conditions, but the mechanisms underlying the pleiotropic effects of RBFOX1 are not yet understood. Here we found that, in zebrafish, rbfox1 is expressed in spinal cord, mid- and hindbrain during developmental stages. In adults, expression is restricted to specific areas of the brain, including telencephalic and diencephalic regions with an important role in receiving and processing sensory information and in directing behaviour. To investigate the contribution of rbfox1 to behaviour, we used rbfox1sa15940, a zebrafish mutant line with TL background. We found that rbfox1sa15940 mutants present hyperactivity, thigmotaxis, decreased freezing behaviour and altered social behaviour. We repeated these behavioural tests in a second rbfox1 mutant line with a different genetic background (TU), rbfox1del19, and found that rbfox1 deficiency affects behaviour similarly in this line, although there were some differences. rbfox1del19 mutants present similar thigmotaxis, but stronger alterations in social behaviour and lower levels of hyperactivity than rbfox1sa15940 fish. Taken together, these results suggest that mutations in rbfox1 lead to multiple behavioural changes in zebrafish that might be modulated by environmental, epigenetic and genetic background effects, and that resemble phenotypic alterations present in Rbfox1-deficient mice and in patients with different psychiatric conditions. Our study, thus, highlights the evolutionary conservation of rbfox1 function in behaviour and paves the way to further investigate the mechanisms underlying rbfox1 pleiotropy on the onset of neurodevelopmental and psychiatric disorders

    Influenţa condiţiilor de păstrare asupra unor compuşi bioactivi din fructele de pădure şi contribuţia acestora asupra sănătăţii umane

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    The main criteria underlying this research consist in assessing the influence of the principal storage technologies on the content of some bioactive compounds contained by berry fruits. To balance fluctuations in product supply and market demand, fresh berry fruits often require short-or long-term storage in order to extend the supply of the berry fruits beyond the end ofthe harvest season. Understanding the interaction between the fruits and the environment is crucial for obtaining the most suitable conditions for extending shelf life. Portions of 250 g of strawberries, cranberries, gooseberries, blackberries or raspberries contain considerably more than the minimum daily requirement of vitamin C, while most of the other fruit can provide more than half the daily requirement. In order to freeze the berries fruits, generally no pretreatments are applied and therefore no changes in nutritive values occur during storage if proper packaging is used. During thawing, however, losses may occur. The fruits were monitorized in three fixed time points of refrigerated storage conditions at 20C, and also after different freezing condition (-180C in laboratory freezing condition and from supermarket freezing condition). The biological material studied was represented by 4 types of berries, as follows: Vaccinum myrtillius, Ribes rubrum, Rubus fructicocus and Rubus idaeus which were asseassed in terms of quality in fresh condition (T0 –moment), and after 3, respectively 7 days of refrigerate storage condition as well as after 6 month of freezing (in bulk and packaged in polyethylene bags). The soluble dry matter substances content was noticed to decrease in refrigerated storage condition between T1 and T2 time points (p<0.001). As concerning the differences in vitamin C content between fruits storage in bulk and packaged with polyethylene film were highlight significantly higher values (p<0.001) for all analyzed species that were packaged also in freezing storage conditions. When compared to the other fruits tested, the red gooseberries (43.5 mg/ 100 g), followed by raspberries (35.6 mg/ 100 g) were evidenced by their high vitamin C content. By keeping the fruits refrigerated for 7 days, although the sensory characteristics have undergone major changes, a significant decrease in vitamin C content is noted, however its final values at Tf moment are still remarkable: 27.8 mg/ 100 g for currants and 24.3 mg/ 100 g for raspberries

    Experimental admixture among geographically disjunct populations of an invasive plant yields a global mosaic of reproductive incompatibility and heterosis

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    1. Invasive species have the ability to rapidly adapt in the new regions where they are introduced. Classic evolutionary theory predicts that the accumulation of genetic differences over time in allopatric isolation may lead to reproductive incompatibilities resulting in decreases in reproductive success and, eventually, to speciation. However, experimental evidence for this theoretical prediction in the context of invasive species is lacking. We aimed to test for the potential of allopatry to determine reproductive success of invasive plants, by experimentally admixing genotypes from six different native and non‐native regions of Centaurea solstitialis, an invasive forb for which preliminary studies have detected some degree of reproductive isolation between one native and non‐native region. 2. We grew plants under common garden conditions and outcrossed individuals originating from different source populations in the native and introduced range to evaluate reproductive success in terms of seed to ovule ratio produced. We also assessed geographical and genetic isolation among C. solstitialis regions as a potential driving factor of reproductive success. 3. Experimental admixture generated mixed fitness effects, including significant increases, decreases and no differences in reproductive success as compared to crosses within population (control). Centaurea solstitialis invasive populations in the Americas generated preponderantly negative fitness interactions, regardless of the pollen source, suggesting selection against immigrants and reinforcement. Other non‐native populations (Australia) as well as individuals from the native range of Spain demonstrated an increase in fitness for between‐region crosses, indicating inbreeding. These differences show an asymmetrical response to inter‐regional gene flow, but no evidence of isolation by distance. 4. Synthesis. The speed of adaptation and the accumulation of reproductive incompatibilities among allopatric populations of invasive species might be more rapid than previously assumed. Our data show a global mosaic of reproductive outputs, showcasing an array of evolutionary processes unfolding during colonization at large biogeographical scales

    Extensive analysis of native and non-native Centaurea solstitialis L. populations across the world shows no traces of polyploidization

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    Centaurea solstitialis L. (yellow starthistle, Asteraceae) is a Eurasian native plant introduced as an exotic into North and South America, and Australia, where it is regarded as a noxious invasive. Changes in ploidy level have been found to be responsible for numerous plant biological invasions, as they are involved in trait shifts critical to invasive success, like increased growth rate and biomass, longer life-span, or polycarpy. C. solstitialis had been reported to be diploid (2n = 2x = 16 chromosomes), however, actual data are scarce and sometimes contradictory. We determined for the first time the absolute nuclear DNA content by flow cytometry and estimated ploidy level in 52 natural populations of C. solstitialis across its native and non-native ranges, around the world. All the C. solstitialis populations screened were found to be homogeneously diploid (average 2C value of 1.72 pg, SD = ±0.06 pg), with no significant variation in DNA content between invasive and non-invasive genotypes. We did not find any meaningful difference among the extensive number of native and non-native C. solstitialis populations sampled around the globe, indicating that the species invasive success is not due to changes in genome size or ploidy level
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