13,793 research outputs found

    Organic production systems in Northern highbush blueberries

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    The production of highbush blueberries is increasing worldwide. Organic production of blueberries in Sweden is presently very limited but is expected to have a great potential to expand as the berries are popular and have a good shelf life. The fact that blueberries require acid soils raises several questions concerning suitable substrates in combination with mycorrhizal inoculation and fertilization in organic production systems. Field and pot experiments have been established during 2011 and 2012 with the aim of developing a sustainable production system for high quality organic blueberries. After the second experimental year, total fruit yields were similar for plants grown in a plastic tunnel and in the open field. Yields were not affected by the addition of 10% forest soil to the peat-based substrate. Inoculation with ericoid mycorrhizal fungi had little effect on shoot length in a greenhouse pot experiment. Blueberries may be particularly suitable for organic production as the need for fertilizers is low combined with a relatively low disease pressure on the blueberry crop in the Nordic countries. The Swedish blueberry production might be expected to expand in the near future. The development of a successful and resource-efficient growing system for organic blueberries may encourage new blueberry growers to chose organic production

    Maternal haemodynamic function differs in pre‐eclampsia when it is associated with a small‐for‐gestational‐age newborn: a prospective cohort study

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    Objective To describe maternal haemodynamic differences in gestational hypertension with small‐for‐gestational‐age babies (HDP + SGA), gestational hypertension with appropriate‐for‐gestational‐age babies (HDP‐only) and control pregnancies. Design Prospective cohort study. Setting Tertiary Hospital, UK. Population Women with gestational hypertension and healthy pregnant women. Methods Maternal haemodynamic indices were measured using a non‐invasive Ultrasound Cardiac Output Monitor (USCOM‐1A®) and corrected for gestational age and maternal characteristics using device‐specific reference ranges. Main outcome measures Maternal cardiac output, stroke volume, systemic vascular resistance. Results We included 114 HDP + SGA, 202 HDP‐only and 401 control pregnancies at 26–41 weeks of gestation. There was no significant difference in the mean arterial blood pressure (110 versus 107 mmHg, P = 0.445) between the two HDP groups at presentation. Pregnancies complicated by HDP + SGA had significantly lower median heart rate (76 versus 85 bpm versus 83 bpm), lower cardiac output (0.85 versus 0.98 versus 0.97 MoM) and higher systemic vascular resistance (1.4 versus 1.0 versus 1.2 MoM) compared with control and HDP‐only pregnancies, respectively (all P < 0.05). Conclusion Women with HDP + SGA present with more severe haemodynamic dysfunction than HDP‐only. Even HDP‐only pregnancies exhibit impaired haemodynamic indices compared with normal pregnancies, supporting a role of the maternal cardiovascular system in gestational hypertension irrespective of fetal size. Central haemodynamic changes may play a role in the pathogenesis of pre‐eclampsia and should be considered alongside placental aetiology

    Evidence for uteroplacental malperfusion in fetuses with major congenital heart defects.

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    AIMS: Fetuses affected by congenital heart defects (CHD) are considered to be at increased risk of fetal growth restriction and intrauterine demise. Whether these risks are a direct consequence of fetal CHD or a result of associated uteroplacental dysfunction is not evident from the data of recent studies. The aim of this study was to investigate the prevalence of uteroplacental dysfunction reflected by abnormal uterine artery Doppler indices and reduced fetal growth in CHD pregnancies. METHODS: This is a retrospective case-control study including singleton pregnancies referred for detailed fetal cardiac assessment subsequently diagnosed with or without CHD. Mid-trimester uterine artery Doppler assessment at 20-24 weeks as well as third trimester fetal biometry and arterial Doppler pulsatility indices (PI) were performed. All fetal biometry were converted into centiles and Doppler values to multiples of median (MoM) to adjust for physiological changes with gestation. RESULTS: The study included 811 pregnancies including 153 cases where the fetus was diagnosed with CHD. Mid-pregnancy uterine artery PI was significantly higher in women with fetal CHD compared to controls (0.90MoM vs 0.83MoM; p = 0.006). In the third trimester, median centiles for fetal head circumference (45.4 vs 57.07; p<0.001), abdominal circumference (51.17 vs 55.71; p = 0.014), estimated fetal weight (33.6 vs 56.7; p<0.001) and cerebroplacental ratio (CPR: 0.84MoM vs 0.95MoM; p<0.001) were significantly lower in fetuses with CHD compared to controls. The percentage of small for gestational age births <10th centile (24.0% vs 10.7%; <0.001) and low CPR <0.6MoM (11.7% vs 2.5%; p<0.001) were significantly higher in the fetal CHD cohort. CONCLUSIONS: Mid-pregnancy uterine artery resistance is increased and subsequent fetal biometry reduced in pregnancies with CHD fetuses. These findings suggest that fetal CHD are associated with uteroplacental dysfunction, secondary to impaired maternal uteroplacental perfusion resulting in relative fetal hypoxaemia and reduced fetal growth

    Record extension for short-gauged water quality parameters using a newly proposed robust version of the Line of Organic Correlation technique

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    In many situations the extension of hydrological or water quality time series at short-gauged stations is required. Ordinary least squares regression (OLS) of any hydrological or water quality variable is a traditional and commonly used record extension technique. However, OLS tends to underestimate the variance in the extended records, which leads to underestimation of high percentiles and overestimation of low percentiles, given that the data are normally distributed. The development of the line of organic correlation (LOC) technique is aimed at correcting this bias. On the other hand, the Kendall-Theil robust line (KTRL) method has been proposed as an analogue of OLS with the advantage of being robust in the presence of outliers. Given that water quality data are characterised by the presence of outliers, positive skewness and non-normal distribution of data, a robust record extension technique is more appropriate. In this paper, four record-extension techniques are described, and their properties are explored. These techniques are OLS, LOC, KTRL and a new technique proposed in this paper, the robust line of organic correlation technique (RLOC). RLOC includes the advantage of the LOC in reducing the bias in estimating the variance, but at the same time it is also robust in the presence of outliers. A Monte Carlo study and empirical experiment were conducted to examine the four techniques for the accuracy and precision of the estimate of statistical moments and over the full range of percentiles. Results of the Monte Carlo study showed that the OLS and KTRL techniques have serious deficiencies as record-extension techniques, while the LOC and RLOC techniques are nearly similar. However, RLOC outperforms OLS, KTRL and LOC when using real water quality records

    Últimos retos en el tratamiento de la catarata congénita

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    La descripció de la cataracta congènita és una opacitat de la lent ocular que apareix en el part o durant la primera infància, és una malaltia rara i sovint desconeguda, però a excepció d'altres raons associades amb ella que inclouen: genètica, metabòlica, infeccions, ús de corticoesteroides, trauma, uveitis, així com anomalies oculars. L'objectiu d'aquest treball és investigar diversos articles sobre els últims reptes del tractament de la cataracta congènita i quins tipus d'enfocaments es poden utilitzar per curar-los i per a l'ambliopia que es produeix a causa de la cataracta. Per a concloure, malgrat l'avanç de les tècniques quirúrgiques per als nens molt millor del que ho va ser fa anys, així que els reptes com la mida de l'ull, l'edat, la selecció d'exàmens de l'OL, l'horari de cirurgia i les complicacions, així com la remodelació de la visió post-cirúrgica; encara existeixen, però sobretot la rehabilitació de la visió i el tractament amblòpic per a les condicions post-cirúrgiques, i per a aquests casos menors, han de ser seguits periòdicament.La descripción de la catarata congénita es una opacidad del cristalino que aparece en el parto o durante la primera infancia, es una enfermedad rara y muchas veces de causa desconocida, pero salvo por otras razones asociadas a ella que incluyen; genéticas, metabólicas, infecciones, uso de corticoides, traumatismos, uveítis, así como anomalías oculares. El objetivo de este trabajo es investigar varios artículos sobre los últimos desafíos del tratamiento de la catarata congénita y qué tipos de enfoques se pueden utilizar para curarlos y para la ambliopía que se produce debido a la catarata. Para concluir, a pesar del avance en las técnicas quirúrgicas para niños mucho mejor que hace años, los desafíos como el tamaño del ojo, la edad, la selección de exámenes de LIO, el cronograma de cirugía y las complicaciones, así como la rehabilitación de la visión posquirúrgica; aún existen, pero sobre todo la rehabilitación de la visión y el tratamiento ambliópico para condiciones post-quirúrgicas, y para aquellos casos menores, deben ser objeto de un seguimiento periódico.The description of congenital cataract is an opaqueness of eye lens that appears at childbirth or during early childhood, It is a rare disease and often unknown cause, but except for other reasons associated with it that include; genetic, metabolic, infections, corticosteroids usage, trauma, uveitis, as well as ocular anomalies. The goal of this work is to research various articles on the latest challenges of treating congenital cataract and what kinds of approaches can be used for curing them and for the amblyopia that is produced due to cataract. To conclude, in spite of the advancement in surgical techniques for children much better than it was years ago, so the challenges such as eye size, age, selection of IOL examinations, surgery schedule, and complications, as well as vision rehab post-surgical; still exist, but most of all the vision rehabilitation and amblyopic treatment for post-surgical conditions, and for those minor cases, they must be followed up periodically
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