332 research outputs found

    Lung function and respiratory outcomes in teenage boys and girls born very prematurely

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    OBJECTIVES: Male sex in prematurely born infants has been associated with worse respiratory outcomes in early childhood. WORKING HYPOTHESIS: Respiratory outcomes at 11 to 14 years of age in children born very prematurely and routinely exposed to antenatal corticosteroids and postnatal surfactant would differ according to sex. STUDY DESIGN: Analysis of follow‐up data. PATIENT-SUBJECT SELECTION: Three hundred and nineteen children born before 29 weeks of gestational age from the United Kingdom Oscillation Study. METHODOLOGY: Spirometry was used to assess forced expiratory flow at 75%, 50%, and 25% of expired vital capacity (FEF_{75}, FEF_{50}, and FEF_{25}), forced expiratory volume in 1 second (FEV_{1}), peak expiratory flow (PEF), and forced vital capacity (FVC). Lung volumes were measured using a helium dilution technique (FRC_{He}) and by plethysmography (FRC_{pleth}). Total lung capacity (TLC) and residual volume (RV) were calculated. Mean lung function measurements were compared using linear mixed models and reported as unadjusted and adjusted for neonatal and age 11 to 14 years factors. The participants also completed health questionnaires and provided a urine sample for assessment of passive or active smoking. RESULTS: Three (FEF_{25}, FEF_{25‐75}, FEV_{1}) lung function measures showed significant differences in favor of females after adjustment. The percentage of children with abnormal lung function (below 5th centile for normal) had adjusted differences between 10 and 30 percentage points, for example, for FEF25 15% females compared with 26% males. CONCLUSIONS: Among extremely prematurely born school children airway function was significantly worse in males

    Psychological Distress in Elite Sambo and Recreational Athletes

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    Background: Previous studies suggest that engagement in any type of physical activity can be protective against mental health issues, whereas elite-level athletes can endure various mental health challenges. The aim of this study was to determine variations in the prevalence of psychological distress among elite sambo athletes and their recreational counterparts. Methods: A sample consisting of 245 athletes (127 males and 118 females) was chosen. Out of the total sample, 105 were elite-level athletes while 140 were recreational athletes. Participants were accessed via the Depression Anxiety Stress Scales-21 to determine their stress in various domains at a given time. Results: Data indicated that all tested differences between elite sambo athletes and recreational athletes were statistically significant; recreational athletes had a higher score on the depression scale, anxiety and stress, and a general distress score than sambo athletes. Although there are no gender differences in psychological distress in the total sample of athletes, elite sambo athletes achieve significantly lower scores in all tested variants than recreational ones. Women who engage in recreational activities have stood out as a vulnerable subsample in psychological stress. Conclusion: Future epidemiological and interventional studies should explore optimal strategies to identify mental health needs based on specific sport activity, especially in terms of gender. There is a need to place special emphasis on psychological distress in the context of combat sports

    Pulmonary Artery Pressures in School-Age Children Born Prematurely

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    Objectives To test the hypothesis that pulmonary artery pressures were higher in school aged children born extremely premature than those born at term. We also wanted to assess whether pulmonary artery pressures differed between children born prematurely with or without bronchopulmonary dysplasia (BPD) or between those randomized in the neonatal period to different ventilation modes. Study design Transthoracic echocardiography was performed on 193 children born extremely premature (106 had BPD) and 110 children born at term when they were 11-14 years of age. Ninety-nine children born extremely premature had been supported by high-frequency oscillation and 94 by conventional ventilation. Tricuspid regurgitation was assessed in the apical 4-chamber and modified parasternal long-axis views. Continuous-wave Doppler of the peak regurgitant jet velocity was used to estimate the right-ventricular-to-right-atrial systolic pressure gradient. Results Tricuspid regurgitation was measurable in 71% (137/193) of the children born preterm and 75% (83/110) of the children born at term (P .23). The children born prematurely compared with the children born at term had a greater peak tricuspid regurgitation velocity (2.21 vs 1.95 m/s, P < .001) and the children born prematurely who had BPD vs those without BPD had a greater peak tricuspid regurgitation velocity (P = .023). There were no significant differences in pulmonary artery pressures according to neonatal ventilation mode. Conclusions Pulmonary artery pressures were estimated to be greater in 11- to 14-year-old children born extremely prematurely compared with those born at term and in those born prematurely who developed BPD compared with those who did not but did not differ significantly by neonatal ventilation mode

    Effect of dexamethasone exposure on the neonatal unit on the school age lung function of children born very prematurely

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    The objective of this study was to determine the impact of postnatal dexamethasone treatment on the neonatal unit on the school age lung function of very prematurely born children. Children born prior to 29 weeks of gestational age had been entered into a randomised trial of two methods of neonatal ventilation (United Kingdom Oscillation Study). They had comprehensive lung function measurements at 11 to 14 years of age. One hundred and seventy-nine children born at a mean gestational age of 26.9 (range 23–28) weeks were assessed at 11 to 14 years; 50 had received postnatal dexamethasone. Forced expiratory flow at 75% (FEF75), 50%, 25% and 25–75% of the expired vital capacity, forced expiratory volume in one second, peak expiratory flow and forced vital capacity and lung volumes including total lung capacity and residual volume were assessed. Lung function outcomes were compared between children who had and had not been exposed to dexamethasone after adjustment for neonatal factors using linear mixed effects regression. After adjustment for confounders all the mean spirometry results were between 0.38 and 0.87 standard deviations lower in those exposed to dexamethasone compared to the unexposed. For example, the mean FEF75z-score was 0.53 lower (95% CI 0.21 to 0.85). The mean lung function was lower as the number of courses of dexamethasone increased. In conclusion, postnatal dexamethasone exposure was associated with lower mean lung function at school age in children born extremely prematurely. Our results suggest the larger the cumulative dose the greater the adverse effect on lung function at follow-up

    Longitudinal assessment of lung function in extremely prematurely born children

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    OBJECTIVES: To assess longitudinally small airway function in children born extremely prematurely and whether there was a correlation between airway function in infancy and at 11-14 years. WORKING HYPOTHESES: There would be tracking of airways obstruction and small airway function would deteriorate during childhood in those born extremely prematurely. STUDY DESIGN: A longitudinal study. PATIENT-SUBJECT SELECTION: Thirty-five children with a mean gestational age of 26 weeks had lung function assessed at 1 year corrected and 11-14 years of age. METHODOLOGY: Lung volumes were measured by helium gas dilution (FRCHe ) and plethysmography (FRCpleth ) and small airway function assessed by calculating the FRCHe :FRCpleth ratio. Airway function was assessed at 1 year corrected by measurement of airway resistance (Raw ) and at 11-14 years by assessment of Raw , forced expiratory flow from 75% of vital capacity (FEF75 ), and forced expiratory volume at one second (FEV1 ). RESULTS: At the first assessment, the children had a mean (SD) FRCHe :FRCpleth of 0.90 (0.13) and at the second, 0.83 (0.12) (P = 0.035). There was a significant 0.54% decrease (95%CI: -1.02%, -0.06%) in FRCHe :FRCpleth for increased age per year after adjusting for birth weight, gestational age, sex, and bronchopulmonary dysplasia (P = 0.027). There were significant correlations between Raw at the first assessment and Raw (P = 0.012), FEF75 (P = 0.034), and FEV1 (P = 0.04) at 11-14 years. CONCLUSIONS: These results demonstrate in those born extremely prematurely there is tracking of airway function during childhood

    Single-cell immune profiling reveals markers of emergency myelopoiesis that distinguish severe from mild respiratory syncytial virus disease in infants.

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    Whereas most infants infected with respiratory syncytial virus (RSV) show no or only mild symptoms, an estimated 3 million children under five are hospitalized annually due to RSV disease. This study aimed to investigate biological mechanisms and associated biomarkers underlying RSV disease heterogeneity in young infants, enabling the potential to objectively categorize RSV-infected infants according to their medical needs. Immunophenotypic and functional profiling demonstrated the emergence of immature and progenitor-like neutrophils, proliferative monocytes (HLA-DRLow , Ki67+), impaired antigen-presenting function, downregulation of T cell response and low abundance of HLA-DRLow B cells in severe RSV disease. HLA-DRLow monocytes were found as a hallmark of RSV-infected infants requiring hospitalization. Complementary transcriptomics identified genes associated with disease severity and pointed to the emergency myelopoiesis response. These results shed new light on mechanisms underlying the pathogenesis and development of severe RSV disease and identified potential new candidate biomarkers for patient stratification

    Effect of Ultrasonic-Assisted Blanching on Size Variation, Heat Transfer, and Quality Parameters of Mushrooms

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    The main aim of this work was to assess the influence of the application of power ultrasound during blanching of mushrooms (60 90 °C) on the shrinkage, heat transfer, and quality parameters. Kinetics of mushroom shrinkage was modeled and coupled to a heat transfer model for conventional (CB) and ultrasonic-assisted blanching (UB). Cooking value and the integrated residual enzymatic activity were obtained through predicted temperatures and related to the hardness and color variations of mushrooms, respectively. The application of ultrasound led to an increase of shrinkage and heat transfer rates, being this increase more intense at low process temperatures. Consequently, processing time was decreased (30.7 46.0 %) and a reduction in hardness (25.2 40.8 %) and lightness (13.8 16.8 %) losses were obtained. The best retention of hardness was obtained by the UB at 60 °C, while to maintain the lightness it was the CB and UB at 90 °C. For enhancing both quality parameters simultaneously, a combined treatment (CT), which consisted of a CB 0.5 min at 90 °C and then an UB 19.9min at 60 °C, was designed. In this manner, compared with the conventional treatment at 60 °C, reductions of 39.1, 27.2, and 65.5 % for the process time, hardness and lightness losses were achieved, respectively. These results suggest that the CT could be considered as an interesting alternative to CB in order to reduce the processing time and improve the overall quality of blanched mushrooms.The authors acknowledge the financial support of Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional de La Plata from Argentina, Erasmus Mundus Action 2-Strand 1 and EuroTango II Researcher Training Program and Ministerio de Economia y Competitividad (SPAIN) and the FEDER (project DPI2012-37466-CO3-03).Lespinard, A.; Bon Corbín, J.; Cárcel Carrión, JA.; Benedito Fort, JJ.; Mascheroni, RH. (2015). Effect of Ultrasonic-Assisted Blanching on Size Variation, Heat Transfer, and Quality Parameters of Mushrooms. Food and Bioprocess Technology. 8(1):41-53. https://doi.org/10.1007/s11947-014-1373-zS415381Aguirre, L., Frias, J. M., Barry-Ryan, C., & Grogan, H. (2009). Modelling browning and brown spotting of mushrooms (Agaricus bisporus) stored in controlled environmental conditions using image analysis. Journal of Food Engineering, 91, 280–286.Anantheswaran, R. C., Sastry, S. K., Beelman, R. B., Okereke, A., & Konanayakam, M. (1986). Effect of processing on yield, color, and texture of canned mushrooms. Journal of Food Science, 51(5), 1197–1200.Biekman, E. S. A., Kroese-Hoedeman, H. I., & Schijvens, E. P. H. M. (1996). Loss of solutes during blanching of mushrooms (Agaricus bisporus) as a result of shrinkage and extraction. Journal of Food Engineering, 28(2), 139–152.Biekman, E. S. A., van Remmen, H. H. J., Kroese-Hoedeman, H. I., Ogink, J. J. M., & Schijvens, E. P. H. M. (1997). Effect of shrinkage on the temperature increase in evacuated mushrooms (Agaricus bisporus) during blanching. Journal of Food Engineering, 33(1–2), 87–99.Brennan, M., Le Port, G., & Gormley, R. (2000). Post-harvest treatment with citric acid or hydrogen peroxide to extend the shelf life of fresh sliced mushrooms. Lebensmittel Wissenschaft und Technologie, 33, 285–289.Cárcel, J. A., Benedito, J., Rosselló, C., & Mulet, A. (2007). Influence of ultrasound intensity on mass transfer in apple immersed in a sucrose solution. Journal of Food Engineering, 78, 472–479.Cárcel, J. A., Benedito, J., Bon, J., & Mulet, A. (2007). High intensity ultrasound effects on meat brining. Meat Science, 76, 611–619.Cárcel, J. A., García-Pérez, J. V., Benedito, J., & Mulet, A. (2011). Food process innovation through new technologies: Use of ultrasound. Journal of Food Engineering, 110, 200–207.Cheng, X., Zhang, M., & Adhikari, B. (2013). The inactivation kinetics of polyphenol oxidase in mushroom (Agaricus bisporus) during thermal and thermosonic treatmemts. Ultrasonics Sonochemistry, 20, 674–679.Cliffe-Byrnes, V., & O’Beirne, D. (2007). Effects of gas atmosphere and temperature on the respiration rates of whole and sliced mushrooms (Agaricus bisporus): implications for film permeability in modified atmosphere packages. Journal of Food Science, 72, 197–204.Coskuner, Y., & Ozdemir, Y. (1997). Effects of canning processes on the elements content of cultivated mushrooms (Agaricus bisporus). Food Chemistry, 60(4), 559–562.Cruz, R. M. S., Vieira, M. C., Fonseca, S. C., & Silva, C. L. M. (2011). Impact of thermal blanching and thermosonication treatments on watercress (Nasturtium officinale) quality: thermosonication process optimisation and microstructure evaluation. Food and Bioprocess Technology, 4(7), 1197–1204.De Gennaro, L., Cavella, S., Romano, R., & Masi, P. (1999). The use of ultrasound in food technology I: inactivation of peroxidase by thermosonication. Journal of Food Engineering, 39, 401–407.De la Fuente, S., Riera, E., Acosta, V. M., Blanco, A., & Gallego-Juárez, J. A. (2006). Food drying process by power ultrasound. Ultrasonics, 44, 523–527.Delgado, A. E., Zheng, L., & Sun, D. W. (2009). Influence of ultrasound on freezing rate of immersion-frozen apples. Food and Bioprocess Technology, 2, 263–270.Devece, C., Rodríguez-López, J. N., Fenoll, J. T., Catalá, J. M., De los Reyes, E., & García-Cánovas, F. (1999). Enzyme inactivation analysis for industrial blanching applications: comparison of microwave, conventional, and combination heat treatments on mushroom polyphenoloxidase activity. Journal of Agricultural and Food Chemistry, 47(11), 4506–4511.Fernandes, F. A. N., & Rodrigues, S. (2007). Ultrasound as pre-treatment for drying of fruits: dehydration of banana. Journal of Food Engineering, 82, 261–267.Gabaldón-Leyva, C. A., Quintero-Ramos, A., Barnard, J., Balandrán-Quintana, R. R., Talamás-Abbud, R., & Jiménez-Castro, J. (2007). Effect of ultrasound on the mass transfer and physical changes in brine bell pepper at different temperatures. Journal of Food Engineering, 81, 374–379.Gallego-Juárez, J. A., Riera, E., De la Fuente, S., Rodríguez-Corral, G., Acosta-Aparicio, V. M., & Blanco, A. (2007). Application of high-power ultrasound for dehydration of vegetables: processes and devices. Drying Technology, 25, 1893–1901.Gamboa-Santos, J., Montilla, A., Soria, A. C., & Villamiel, M. (2012). Effects of conventional and ultrasound blanching on enzyme inactivation and carbohydrate content of carrots. European Food Research and Technology, 234, 1071–1079.García-Pérez, J. V., Cárcel, J. A., De la Fuente, S., & Riera, E. (2006). Ultrasonic drying of foodstuff in a fluidized bed. Parametric study. Ultrasonics, 44, 539–543.García-Pérez, J. V., Cárcel, J. A., Riera, E., Rosselló, C., & Mulet, A. (2012). Intensification of low-temperature drying by using ultrasound. Drying Technology, 30, 1199–1208.Gonzáles-Fandos, E., Giménez, M., Olarte, C., Sanz, S., & Simón, A. (2000). Effect of packaging conditions on the growth of microorganisms and the quality characteristics of fresh mushrooms (Agaricus bisporus) stored at inadequate temperatures. Journal of Applied Microbiology, 89, 624–632.Gormley, T. R. (1975). Chill storage of mushrooms. Journal of the Science of Food and Agriculture, 26, 401–411.Gouzi, H., Depagne, C., & Coradin, T. (2012). Kinetics and thermodynamics of thermal inactivation of polyfenol oxidase in an aqueous extract from Agaricus bisporus. Journal of Agricultural and Food Chemistry, 60, 500–506.Holdsworth, S. D. (1997). Thermal processing of packaged foods. London: Chapman Hall.Horžić, D., Jambrak, A. R., Belščak-Cvitanović, A., Komes, D., & Lelas, V. (2012). Comparison of conventional and ultrasound assisted extraction techniques of yellow tea and bioactive composition of obtained extracts. Food and Bioprocess Technology, 5, 2858–2870.Jambrak, A. R., Mason, T. J., Paniwnyk, L., & Lelas, V. (2007a). Ultrasonic effect on pH, electric conductivity, and tissue surface of button mushrooms, brussels sprouts and cauliflower. Czech Journal of Food Science, 25, 90–99.Jambrak, A. R., Mason, T. J., Paniwnyk, L., & Lelas, V. (2007b). Accelerated drying of button mushrooms, Brussels sprouts and cauliflower by applying power ultrasound and its rehydration properties. Journal of Food Engineering, 81, 88–97.Jasinski, E. M., Stemberger, B., Walsh, R., & Kilara, A. (1984). Ultra structural studies of raw and processed tissue of the major cultivated mushroom, Agaricus bisporus. Food Microstructure, 3, 191–196.Jolivet, S., Arpin, N., Wicher, H. J., & Pellon, G. (1998). Agaricus bisporus browning: a review. Mycological Research, 102, 1459–1483.Konanayakam, M., & Sastry, S. K. (1988). Kinetics of shrinkage of mushroom during blanching. Journal of Food Science, 53(5), 1406–1411.Kotwaliwale, N., Bakane, P., & Verma, A. (2007). Changes in textural and optical properties of oyster mushroom during hot air drying. Journal of Food Engineering, 78(4), 1207–1211.Leadley C. & Williams A. (2002). Power ultrasound—current and potential applications for food processing, Review No 32, Campden and Chorleywood Food Research Association.Lespinard, A. R., Goñi, S. M., Salgado, P. R., & Mascheroni, R. H. (2009). Experimental determination and modeling of size variation, heat transfer and quality indexes during mushroom blanching. Journal of Food Engineering, 92, 8–17.Lima, M., & Sastry, S. K. (1990). Influence of fluid rheological properties and particle location on ultrasound-assisted heat transfer between liquid and particles. Journal of Food Science, 55(4), 1112–1115.López, P., & Burgos, J. (1995). Peroxidase stability and reactivation after heat treatment and manothermosonication. Journal of Food Science, 60(3), 551–553.López, P., Sala, F. J., Fuente, J. L., Cardon, S., Raso, J., & Burgos, J. (1994). Inactivation of peroxidase lipoxigenase and phenol oxidase by manothermosonication. Journal of Agricultural and Food Chemistry, 42(2), 253–256.Mansfield, T. (1962). High temperature-short time sterilization. Proceedings First International Congress on Food Science and Technology, 4, 311–316.Mason T. J. (1998). Power ultrasound in food processing—the way forward. In M. J. W. Povey & T. J. Mason (Eds.), Ultrasound in Food Processing (pp 103–126). Blackie Academic & Professional, London.McArdle F. J. & Curwen D. (1962). Some factors influencing shrinkage of canned mushrooms. Mushroom Science, 5, 547–557.McArdle, F. J., Kuhn, G. D., & Beelman, R. B. (1974). Influence of vacuum soaking on yield and quality of canned mushrooms. Journal of Food Science, 39, 1026–1028.Mohapatra, D., Bira, Z. M., Kerry, J. P., Frías, J. M., & Rodrigues, F. A. (2010). Postharvest hardness and color evolution of White button mushrooms (Agaricus bisporus). Journal of Food Science, 75(3), 146–152.Ohlsson, T. (1980). Temperature dependence of sensory quality changes during thermal processing. Journal of Food Science, 45(4), 836–847.Ortuño, C., Martínez-Pastor, M., Mulet, A., & Benedito, J. (2013). Application of high power ultrasound in the supercritical carbon dioxide inactivation of Saccharomyces cerevisiae. Food Research International, 51, 474–481.Peralta-Jimenez, L., & Cañizares-Macías, M. P. (2012). Ultrasound-assisted method for extraction of theobromine and caffeine from cacao seeds and chocolate products. Food and Bioprocess Technology, 6, 3522–3529.Rodríguez-López, J. N., Fenoll, N. G., Tudela, J., Devece, C., Sánchez-Hernández, D., De los Reyes, D., et al. (1999). Thermal inactivation of mushroom polyphenoloxidase employing 2450 MHz microwave radiation. Journal of Agricultural Food Chemistry, 47, 3028–3035.Sala, F., Burgos, J., Condon, S., Lopez, P., & Raso, J. (1995). Effect of heat and ultrasound on microorganisms and enzymes. In G. W. Gould (Ed.), New methods of food preservation (1st ed., pp. 176–204). Glasgow: Blackie Academic and professional.Sanjuán, N., Hernando, I., Lluch, M. A., & Mullet, A. (2005). Effects of low temperature blanching on texture, microstructure and rehydration capacity of carrots. Journal of the Science of Food and Agriculture, 85, 2071–2076.Santos, M. V., & Lespinard, A. R. (2011). Numerical simulation of mushrooms during freezing using the FEM and an enthalpy—Kirchhoff formulation. Heat and Mass Transfer, 47, 1671–1683.Sastry, S. K., Beelman, R. B., & Speroni, J. J. (1985). A three-dimensional finite element model for thermally induced changes in foods: application to degradation of agaritine in canned mushrooms. Journal of Food Science, 50(5), 1293–1299.Sastry, S. K., Shen, G. Q., & Blaisdel, J. L. (1989). Effect of ultrasonic vibration on fluid-to-particule convective heat transfer coefficients. Journal of Food Science, 54(1), 229–230.Sensoy, I., & Sastry, S. K. (2004). Ohmic blanching of mushrooms. Journal of Food Process Engineering, 27(1), 1–15.Sheen, S., & Hayakawa, K. (1991). Finite difference simulation for heat conduction with phase change in an irregular food domain with volumetric change. International Journal of Heat and Mass Transfer, 34(6), 1337–1346.Simal, S., Benedito, J., Sanchez, E. S., & Rossello, C. (1998). Use of ultrasound to increase mass transport rates during osmotic dehydration. Journal of Food Engineering, 36, 323–336.Siró, I., Vén, C., Balla, C., Jónás, G., Zeke, I., & Friedrich, L. (2009). Application of an ultrasonic assisted curing technique for improving the diffusion of sodium chloride in porcine meat. Journal of Food Engineering, 91, 353–362.Soria, A. C., & Villamiel, M. (2010). Effect of ultrasound on the technological properties and bioactivity in foods: a review. Trends in Food Science and Technology, 21, 323–331.Verlinden, B. E., Yuksel, D., Baheri, M., De Baerdemaeker, J., & Van Dijk, C. (2000). Low temperature blanching effect on the changes in mechanical properties during subsequent cooking of three potato cultivars. International Journal of Food Science and Technology, 35, 331–340.Wu, C. M., Wu, J. L.-P., Chen, C.-C., & Chou, C.-C. (1981). Flavor recovery from mushroom blanching water. In G. Charalambous & G. Inglett (Eds.), The quality of foods and beverages: chemistry and technology, vol. 1. New York: Academic Press.Zivanovic, S., & Buescher, R. (2004). Changes in mushroom texture and cell wall composition affected by thermal processing. Journal of Food Science, 69, 44–48

    Absolute Quantification of Plasma Apolipoproteins for Cardiovascular Disease Risk Prediction

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    Apolipoproteins have important structural and functional roles in several lipoprotein particles. Apolipoproteins regulate lipid metabolism, adipose tissue, and energy production and serve major regulatory roles in both pre- and pro-atherosclerotic mechanisms. They are also involved in protective mechanisms against atherosclerotic plaques. Therefore, accurate quantification of apolipoproteins may serve as a crucial biomarker for cardiovascular diseases. However, most apolipoproteins cannot be detected using standard clinical immunoassays, and multiplexing is not available for some species of apolipoproteins. Herein, we describe a highly robust and quantitative method using liquid chromatography coupled to tandem mass spectrometry to quantify apolipoproteins in plasma. This methodology may add clinical value for profiling cardiovascular risk in vulnerable individuals and enable monitoring of apolipoprotein levels in plasma following intervention strategies.Australian Research Council Discovery Early Career Research Award at the University of New South Wales, Sydney, AustraliaN.B. is the recipient of the Australian Research Council Discovery Early Career Research Award at the University of New SouthWales, Sydney, Australia

    Stable population structure in Europe since the Iron Age, despite high mobility

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    Ancient DNA research in the past decade has revealed that European population structure changed dramatically in the prehistoric period (14,000-3000 years before present, YBP), reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries. However, little is known about how population structure changed from the historical period onward (3000 YBP - present). To address this, we collected whole genomes from 204 individuals from Europe and the Mediterranean, many of which are the first historical period genomes from their region (e.g. Armenia and France). We found that most regions show remarkable inter-individual heterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region where they were sampled, some indicating cross-Mediterranean contacts. Despite this high level of mobility, overall population structure across western Eurasia is relatively stable through the historical period up to the present, mirroring geography. We show that, under standard population genetics models with local panmixia, the observed level of dispersal would lead to a collapse of population structure. Persistent population structure thus suggests a lower effective migration rate than indicated by the observed dispersal. We hypothesize that this phenomenon can be explained by extensive transient dispersal arising from drastically improved transportation networks and the Roman Empire's mobilization of people for trade, labor, and military. This work highlights the utility of ancient DNA in elucidating finer scale human population dynamics in recent history
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