490 research outputs found
Real time 100 Gbit/s electrical Nyquist WDM transmitter
We demonstrate the use of passive electrical filters to produce high quality spectrally-shaped 29 Gbaud WDM signals with a 20 dB bandwidth of 32 GHz, a roll-off of 4.8 dB/GHz and a required OSNR of 12.1 dB
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Error probability performance of a short-reach multicore fiber optical interconnect transmission system
A standalone module for rectangular array multicore fiber (MCF)-based optical interconnect (OI) is realized that includes inherent intercore crosstalk and provides space division multiplexed coupling/decoupling of optical power. The module is integrated in a short-reach communication system to provide bit error probability (BEP). Next, a closed-form equation for BEP applicable to MCF OI with intercore crosstalk is derived. For characteristic parameters of the module, results obtained by two approaches agree within 1% for 40 Gbps per channel and predict an error-free transmission of aggregated data rate of 2.5 Tbps through the MCF OI under consideration
Prevalence and predictors of poor mental health among pregnant women in Wales using a cross-sectional survey
Objectives
To assess the prevalence of self-reported mental health problems in a cohort of women in early pregnancy.
To describe the relationship between poor mental health and sociodemographic characteristics, self-efficacy and support networks.
To assess if participants were representative of the local antenatal population.
Research design and setting
The UK government has pledged money to provide more support for women with perinatal mental health issues. Understanding the prevalence and predicting women who may need support will inform clinical practice. This paper reports part of the larger ‘Mothers Mood Study’, which explored women's and midwives’ experience of mild to moderate perinatal mental health issues and service provision. Routinely collected population level data were analysed and a smaller cross-sectional survey design used to assess predictors of poor mental health in early pregnancy in one health board in Wales.
Participants
Routinely collected data were extracted for all women who registered for maternity care between May 2017 and May 2018 (n = 6312) from the electronic maternity information system (pregnant population). Over a three month period 302 of these women completed a questionnaire at the antenatal clinic after an ultrasound scan (participants). Eligible women were aged ≥18 years, with sufficient spoken and written English to complete the questionnaire and a viable pregnancy of ≤18 weeks’ gestation. The questionnaire collected data on sociodemographic status, self-efficacy and support networks, self-reported mental health problems. Current anxiety and depression were assessed using the General Anxiety Disorders Assessment and Edinburgh Postnatal Depression Scale.
Findings
Among the pregnant population 23% (n = 1490) disclosed a mental health problem during routine questioning with anxiety and depression being the most common conditions. Participants completing the detailed questionnaire were similar in age and parity to the pregnant population with similar levels of depression (15.6%; n = 15.6 v 17.3%, n = 1092). Edinburgh Postnatal Depression Scale and General Anxiety Disorder 7 scores identified 8% with symptoms of anxiety (n = 25) or depression (n = 26) and a further 24.2% (n = 73) with symptoms of mild anxiety and 25.2% (n = 76) with mild depression. Low self-efficacy (OR 1.27, 95% CI 1.12–1.45), a previous mental health problem (OR 3.95, 95% CI 1.37–11.33) and low support from family (OR 1.13, 95% CI 1.00–1.27) were found to be associated with early pregnancy anxiety and/or depression.
Key conclusions and implications for practice
Around one in five women who register for maternity care may have a mental health problem. Mild to moderate anxiety and depression are common in early pregnancy. Services need to improve for women who do not currently meet the threshold for referral to perinatal mental health services. Assessment and active monitoring of mental health is recommended, in particular for pregnant women with risk factors including a history of previous mental health difficulties, poor family support or low self-efficacy
Cardiorespiratory fitness is associated with hard and light intensity physical activity but not time spent sedentary in 10–14 year old schoolchildren: the HAPPY study
Sedentary behaviour is a major risk factor for developing chronic diseases and is associated with low cardiorespiratory fitness in adults. It remains unclear how sedentary behaviour and different physical activity subcomponents are related to cardiorespiratory fitness in children. The purpose of this study was to assess how sedentary behaviour and different physical activity subcomponents are associated with 10–14 year-old schoolchildren's cardiorespiratory fitness
Associations between cardiorespiratory fitness, physical activity and clustered cardiometabolic risk in children and adolescents: the HAPPY study
Clustering of cardiometabolic risk factors can occur during childhood and predisposes individuals to cardiometabolic disease. This study calculated clustered cardiometabolic risk in 100 children and adolescents aged 10-14 years (59 girls) and explored differences according to cardiorespiratory fitness (CRF) levels and time spent at different physical activity (PA) intensities. CRF was determined using a maximal cycle ergometer test, and PA was assessed using accelerometry. A cardiometabolic risk score was computed as the sum of the standardised scores for waist circumference, blood pressure, total cholesterol/high-density lipoprotein ratio, triglycerides and glucose. Differences in clustered cardiometabolic risk between fit and unfit participants, according to previously proposed health-related threshold values, and between tertiles for PA subcomponents were assessed using ANCOVA. Clustered risk was significantly lower (p < 0.001) in the fit group (mean 1.21 ± 3.42) compared to the unfit group (mean -0.74 ± 2.22), while no differences existed between tertiles for any subcomponent of PA. Conclusion These findings suggest that CRF may have an important cardioprotective role in children and adolescents and highlights the importance of promoting CRF in youth
Choice of activity-intensity classification thresholds impacts upon accelerometer-assessed physical activity-health relationships in children
It is unknown whether using different published thresholds (PTs) for classifying physical activity (PA) impacts upon activity-health relationships. This study explored whether relationships between PA (sedentary [SED], light PA [LPA], moderate PA [MPA], moderate-to-vigorous PA, vigorous PA [VPA]) and health markers differed in children when classified using three different PTs
The Grown in Wales Study: Examining dietary patterns, custom birthweight centiles and the risk of delivering a small-for-gestational age (SGA) infant
Objectives
Maternal lifestyles, including diet, have been linked to infant birthweight. However, customised birthweight centiles (CBWC), which more accurately identify small babies that have increased fetal growth restriction and are at higher risk of newborn morbidity and later life health complications, are rarely considered when studying maternal diet. This study investigated maternal dietary patterns and their impact on infant CBWC within a cohort of women living in South Wales.
Methods
This study utilised cross-sectional data from the longitudinal Grown in Wales (GiW) cohort. Women 18–45 years old were recruited the morning prior to an elective caesarean section (ELCS). Women completed a food frequency questionnaire (FFQ). Additional data on pregnancy and birth outcomes was extracted from medical notes. Data from 303 participants was analysed.
Results
‘Western’ and ‘Health conscious dietary patterns were identified. The ‘Health Conscious’ dietary pattern was significantly associated with maternal BMI, age, education, income and exercise. Adjusted regression analyses indicated that greater adherence to a ‘Health Conscious’ dietary pattern was significantly associated with increased CBWC (AOR = 4.75 [95% CI: 1.17, 8.33] p = .010) and reduced risk of delivering a small-for-gestational age (SGA) infant (AOR = .51 [95% CI: .26, .99] p = .046).
Conclusion
A healthier diet was significantly associated with higher birthweight using CBWC and a reduced risk of delivering an SGA infant suggesting that birthweight will be improved in areas of Wales by focused support encouraging healthier dietary habits
Unrepeatered Transmission Over 253.4 km Ultra Low Loss Fibre Achieving 6.95 (b/s)/Hz Se Using EDFA-Only Pre-Amplifier
A 560 Gb/s (7×80 Gb/s Nyquist spaced PDM-16QAM) superchannel achieving 6.95 b/s/Hz spectral efficiency is transmitted over 253.4 km SMF-28® ULL fiber using only EDFA pre-amplification and full-field nonlinear back-propagation, corresponding to a record SE-distance product of 1761.1 b/s/Hz·km
Seasonal variation in salivary cortisol but not symptoms of depression and trait anxiety in pregnant women undergoing an elective caesarean section
Objectives
Seasonal changes in mood and behaviour are commonly reported in the general population but considerably less is known regarding seasonality and pregnancy. This study investigated the relationship between seasons and depression and anxiety symptoms, salivary cortisol concentrations, custom birthweight centiles (CBWC) and placenta weight for pregnant women living in South Wales.
Methods
This study utilised data from the longitudinal Grown in Wales (GiW) cohort. Women were recruited at the presurgical elective caesarean section (ELCS) appointment, when they provided saliva samples and completed the Edinburgh Postnatal Depression Scale (EPDS) and trait subscale of the State-Trait Anxiety Inventory (STAI). Data on birthweight and placental weight was extracted from medical notes. Seasonal data was available for 316 participants.
Results
No association was identified between seasons and EPDS (p = .178), STAI scores (p = .544), CBWC (p = .683) or placental weight (p = .857). Significance was identified between seasons and salivary cortisol concentration (p<.001), with highest levels in autumn and winter. Adjusted linear regression identified spring (B=−.05, p=.007, 95% CI −.09, −.01) and summer (B=−.06, p = .001, 95% CI −09, −.02) compared to autumn, and spring (B=−.05, p=.009, 95% CI −.09, −.01) and summer (B=−.06, p=.002, 95% CI −.10, −.02) compared to winter to be associated with decreased cortisol concentrations.
Conclusion
This study found no association between season and maternally-reported mental health symptoms, birthweight by CBWC or placental weight but did between season and term salivary cortisol. This finding will have implications for studies that do not account for seasonality when using salivary cortisol as a biomarker
Measuring motivation for appetitive behaviour: food-restricted broiler breeder chickens cross a water barrier to forage in an area of wood shavings without food
Broiler breeders (parents of meat chickens) are selected for fast growth and become obese if fed ad libitum. To avoid this and maintain good health and reproductive ability, they are feed restricted to about 1/3 of what they would eat ad libitum. As a result, they experience chronic hunger and exhibit abnormal behaviour patterns that may indicate stress and frustration. One approach to measuring hunger is to observe how much birds will work, such as pecking a key, for access to more or different types of food. However, the sight, smell, and feedback from consumption of the feed reward changes the context and may artificially raise feeding motivation. To avoid this, we tested broiler breeders in an apparatus in which they could work for access to a wooden platform covered in wood shavings by crossing a water runway which increased in length and depth in 8 successive tests. In the wood shavings area, they could perform exploratory and foraging behaviour (the appetitive phase of feeding) but were never rewarded with feed. Sixty birds were divided into three feed quantity treatments: commercial restriction (R), and twice (2R) or three times (3R) this amount. Overall, birds fed R worked harder to reach the wood shavings area (reached it in a larger number of tests) than 2R and 3R birds (P2R>3R). This indicates that restricted-fed birds were hungry and willing to work for the opportunity to forage even though food was never provided, suggesting that their motivation to perform the appetitive component of feeding behaviour (foraging/food searching) was sufficient to sustain their response. Thus food restriction in broiler breeders is a welfare concern. However these methods could be used to test alternative feeding regimes to attempt to find ways of alleviating hunger while still maintaining healthy growth and reproduction in these birds
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