110 research outputs found

    EFFECTS OF HIGH AND LOW MANAGEMENT INTENSITY ON PROFITABILITY FOR THREE WATERMELON GENOTYPES

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    A replicated, small plot study on watermelon [Citrullus lanatus (Thunberg) Matsumura and Nakai] in 1997, 1999, and 2000 revealed that production management intensity affected yields and profitability of watermelon, in Oklahoma. Management intensity was based on a combination of cultural practices and levels of use of production methods. Low intensity management (LM) consisted of use of soil fertilization and weed control. High intensity management (HM) included the same weed control and fertilization as LM but also included use of plastic mulch, drip irrigation, insect pest control, and plant disease control. Cost and return analyses were based on the range of actual prices during the cropping season and the range of yields during the three years. Yields from the seedless triploid genotype 'Gem Dandy' consistently resulted in greater positive net revenue under HM than the diploid open pollinated 'Allsweet' or the hybrid diploid 'Sangria'. Under LM, yields from the seedless triploid also resulted in greater net revenues when conditions were favorable or lost less money than the open pollinated 'Allsweet' or the hybrid diploid 'Sangria' when conditions were unfavorable.Crop Production/Industries,

    Sensitivity of markers of DNA stability and DNA repair activity to folate supplementation in healthy volunteers

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    We have previously reported that supplementation with folic acid (1.2 mg day−1 for 12 week) elicited a significant improvement in the folate status of 61 healthy volunteers. We have examined effects of this supplement on markers of genomic stability. Little is known about the effect of folate supplementation on DNA stability in a cohort, which is not folate deficient. Preintervention, there was a significant inverse association between uracil misincorporation in lymphocyte DNA and red cell folate (P<0.05). In contrast, there were no associations between folate status and DNA strand breakage, global DNA methylation or DNA base excision repair (measured as the capacity of the lymphocyte extract to repair 8-oxoGua ex vivo). Folate supplementation elicited a significant reduction in uracil misincorporation (P<0.05), while DNA strand breakage and global DNA methylation remained unchanged. Increasing folate status significantly decreased the base excision repair capacity in those volunteers with the lowest preintervention folate status (P<0.05). Uracil misincorporation was more sensitive to changes in folate status than other measures of DNA stability and therefore could be considered a specific and functional marker of folate status, which may also be relevant to cancer risk in healthy people

    A case study of electron precipitation fluxes due to plasmaspheric hiss

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    We find that during a large geomagnetic storm in October 2011 the trapped fluxes of >30, >100, and >300 keV outer radiation belt electrons were enhanced at L=3-4 during the storm main phase. A gradual decay of the trapped fluxes was observed over the following 5–7 days, even though no significant precipitation fluxes could be observed in the Polar Orbiting Environmental Satellite (POES) electron precipitation detectors. We use the Antarctic-Arctic Radiation-belt (Dynamic) Deposition - VLF Atmospheric Research Konsortium (AARDDVARK) receiver network to investigate the characteristics of the electron precipitation throughout the storm period. Weak electron precipitation was observed on the dayside for 5–7 days, consistent with being driven by plasmaspheric hiss. Using a previously published plasmaspheric hiss-induced electron energy e-folding spectrum of E0=365 keV, the observed radiowave perturbation levels at L=3-4 were found to be caused by >30 keV electron precipitation with flux ~100 el. cm−2 s−1 sr−1. The low levels of precipitation explain the lack of response of the POES telescopes to the flux, because of the effect of the POES lower sensitivity limit and ability to measure weak diffusion-driven precipitation. The detection of dayside, inner plasmasphere electron precipitation during the recovery phase of the storm is consistent with plasmaspheric hiss wave-particle interactions, and shows that the waves can be a significant influence on the evolution of the outer radiation belt trapped flux that resides inside the plasmapause

    Relationship between physical performance testing results and peak running intensity during professional rugby league match play

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    The purpose of this study was to examine the relationship between individual athletes' physical characteristics and both the peak running intensities and the decline in peak running intensities during competition. Twenty-two professional rugby league athletes (age; 24.1 ± 4.0 years, body mass; 101.4 ± 9.5 kg) underwent a series of physical testing procedures. Peak running intensity was determined using a moving average technique, applied to the speed (m·min-1), acceleration/deceleration (m·s-2) and metabolic power (W·kg-1) during competition, across 10 different durations. The power law relationship was then established, yielding an intercept and slope for the movement variables. Mixed linear models were then used to determine the relationship between physical characteristics and intercept and slope values. There were large, positive relationships between a player’s maximal speed and both peak running speeds (ES = 0.56, 90% CI: 0.20 to 0.78) and metabolic power (0.57, 0.21 to 0.79) during competition. In contrast, there were large, negative associations between maximal speed and the rate of decline in running speed (-0.60, -0.81 to -0.27) and metabolic power (-0.65, -0.83 to -0.32) during competition. Similarly, there were negative associations between relative squat strength and the rate of decline in running speed (moderate: -0.41, -0.69 to -0.04) and metabolic power (large: -0.53, -0.77 to -0.17) during competition. The findings of this study demonstrate that a players running intensity during competition is underpinned by the individual athletes physiological qualities. Athletes demonstrating higher maximal speeds in testing were able to maintain higher running intensities over short durations, but had a greater decrease in running intensity as duration increased

    Using 3D Imaging and Machine Learning to Predict Liveweight and Carcass Characteristics of Live Finishing Beef Cattle

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    Selection of finishing beef cattle for slaughter and evaluation of performance is currently achieved through visual assessment and/or by weighing through a crush. Consequently, large numbers of cattle are not meeting target specification at the abattoir. Video imaging analysis (VIA) is increasingly used in abattoirs to grade carcasses with high accuracy. There is potential for three-dimensional (3D) imaging to be used on farm to predict carcass characteristics of live animals and to optimise slaughter selections. The objectives of this study were to predict liveweight (LW) and carcass characteristics of live animals using 3D imaging technology and machine learning algorithms (artificial neural networks). Three dimensional images and LW's were passively collected from finishing steer and heifer beef cattle of a variety of breeds pre-slaughter (either on farm or after entry to the abattoir lairage) using an automated camera system. Sixty potential predictor variables were automatically extracted from the live animal 3D images using bespoke algorithms; these variables included lengths, heights, widths, areas, volumes, and ratios and were used to develop predictive models for liveweight and carcass characteristics. Cold carcass weights (CCW) for each animal were provided by the abattoir. Saleable meat yield (SMY) and EUROP fat and conformation grades were also determined for each individual by VIA of half of the carcass. Performance of prediction models was assessed using R2 and RMSE parameters following regression of predicted and actual variables for LW (R2 = 0.7, RMSE = 42), CCW (R2 = 0.88, RMSE = 14) and SMY (R2 = 0.72, RMSE = 14). The models predicted EUROP fat and conformation grades with 54 and 55% accuracy (R2), respectively. This study demonstrated that 3D imaging coupled with machine learning analytics can be used to predict LW, SMY and traditional carcass characteristics of live animals. This system presents an opportunity to reduce a considerable inefficiency in beef production enterprises through autonomous monitoring of finishing cattle on the farm and marketing of animals at the optimal time

    Mild folate deficiency induces genetic and epigenetic instability and phenotype changes in prostate cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Folate (vitamin B9) is essential for cellular proliferation as it is involved in the biosynthesis of deoxythymidine monophosphate (dTMP) and s-adenosylmethionine (AdoMet). The link between folate depletion and the genesis and progression of cancers of epithelial origin is of high clinical relevance, but still unclear. We recently demonstrated that sensitivity to low folate availability is affected by the rate of polyamine biosynthesis, which is prominent in prostate cells. We, therefore, hypothesized that prostate cells might be highly susceptible to genetic, epigenetic and phenotypic changes consequent to folate restriction.</p> <p>Results</p> <p>We studied the consequences of long-term, mild folate depletion in a model comprised of three syngenic cell lines derived from the transgenic adenoma of the mouse prostate (TRAMP) model, recapitulating different stages of prostate cancer; benign, transformed and metastatic. High-performance liquid chromatography analysis demonstrated that mild folate depletion (100 nM) sufficed to induce imbalance in both the nucleotide and AdoMet pools in all prostate cell lines. Random oligonucleotide-primed synthesis (ROPS) revealed a significant increase in uracil misincorporation and DNA single strand breaks, while spectral karyotype analysis (SKY) identified five novel chromosomal rearrangements in cells grown with mild folate depletion. Using global approaches, we identified an increase in CpG island and histone methylation upon folate depletion despite unchanged levels of total 5-methylcytosine, indicating a broad effect of folate depletion on epigenetic regulation. These genomic changes coincided with phenotype changes in the prostate cells including increased anchorage-independent growth and reduced sensitivity to folate depletion.</p> <p>Conclusions</p> <p>This study demonstrates that prostate cells are highly susceptible to genetic and epigenetic changes consequent to mild folate depletion as compared to cells grown with supraphysiological amounts of folate (2 μM) routinely used in tissue culture. In addition, we elucidate for the first time the contribution of these aspects to consequent phenotype changes in epithelial cells. These results provide a strong rationale for studying the effects of folate manipulation on the prostate <it>in vivo</it>, where cells might be more sensitive to changes in folate status resulting from folate supplementation or antifolate therapeutic approaches.</p

    Targeting DNA Damage Response and Replication Stress in Pancreatic Cancer

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    Background and aims: Continuing recalcitrance to therapy cements pancreatic cancer (PC) as the most lethal malignancy, which is set to become the second leading cause of cancer death in our society. The study aim was to investigate the association between DNA damage response (DDR), replication stress and novel therapeutic response in PC to develop a biomarker driven therapeutic strategy targeting DDR and replication stress in PC. Methods: We interrogated the transcriptome, genome, proteome and functional characteristics of 61 novel PC patient-derived cell lines to define novel therapeutic strategies targeting DDR and replication stress. Validation was done in patient derived xenografts and human PC organoids. Results: Patient-derived cell lines faithfully recapitulate the epithelial component of pancreatic tumors including previously described molecular subtypes. Biomarkers of DDR deficiency, including a novel signature of homologous recombination deficiency, co-segregates with response to platinum (P &lt; 0.001) and PARP inhibitor therapy (P &lt; 0.001) in vitro and in vivo. We generated a novel signature of replication stress with which predicts response to ATR (P &lt; 0.018) and WEE1 inhibitor (P &lt; 0.029) treatment in both cell lines and human PC organoids. Replication stress was enriched in the squamous subtype of PC (P &lt; 0.001) but not associated with DDR deficiency. Conclusions: Replication stress and DDR deficiency are independent of each other, creating opportunities for therapy in DDR proficient PC, and post-platinum therapy

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

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    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
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