1,379 research outputs found
An Alternate Method for Fourier Transform Infrared (FTIR) Spectroscopic Determination of Soil Nitrate Using Derivative Analysis and Sample Treatments
This study aimed at examining effective sample treatments and spectral processing for an alternate method of soil nitrate determination using the attenuated total reflectance (ATR) of Fourier transform infrared (FTIR) spectroscopy. Prior to FTIR measurements, soil samples were prepared as paste to enhance adhesion between the ATR crystal and sample. The similar nitrate peak heights of soil pastes and their supernatants indicated that the nitrate in the liquid portion of the soil paste mainly responded to the FTIR signal. Using a 0.01-M CaSO4 solution for the soil paste, which has no interference bands in the characteristic spectra of the analyte, increased the concentration of the nitrates to be measured. Second-order derivatives were used in the prediction model to minimize the interference effects and enhance the performance. The second-order derivative spectra contained a unique nitrate peak in a range of 1,400-1,200 cm(-1) without interference of carbonate. A partial least square regression model using second-order derivative spectra performed well (R (2) = 0.995, root mean square error (RMSE) = 23.5, ratio of prediction to deviation (RPD) = 13.8) on laboratory samples. Prediction results were also good for a test set of agricultural field soils with a CaCO3 concentration of 6% to 8% (R (2) = 0.97, RMSE = 18.6, RPD = 3.5). Application of the prediction model based on soil paste samples to nitrate stock solution resulted in an increased RMSE (62.3); however, validation measures were still satisfactory (R (2) = 0.99, RPD = 3.0
Comprehensiveness of infant formula and bottle feeding resources: A review of information from Australian healthcare organisations.
The use of infant formula is widespread internationally. In Australia, 55% of infants receive formula before 6 months of age, with higher rates among disadvantaged communities. Infant formula use can contribute to childhood overweight and obesity, through formula composition and feeding behaviours, such as adding cereal to bottles and parental feeding style. While information abounds to promote and support breastfeeding, formula-feeding parents report a paucity of advice and support; many rely on formula packaging for information. This study systematically searched and reviewed online resources for infant formula and bottle feeding from Australian governments, health services, hospitals, and not-for-profit parenting organisations. A comprehensive search strategy located 74 current resources, mostly for parents. Researchers evaluated the resources against best practice criteria derived from Australian government and UNICEF guidelines on six topics. They assessed how comprehensively the resources addressed each topic and whether the resources provided all the information necessary for parents to understand each topic. The mean 'comprehensiveness' rating for topics across all resources was 54.36%. However, some topics were addressed more fully than others. Information on 'discussing infant formula with health workers' and on 'preparing infant formula' was more frequently accurate and comprehensive. However, there was much less comprehensive information on 'using infant formula', including amounts of formula to feed, use of bottle teats, appropriate bottle-feeding practice and responsiveness to infant satiety cues. Over half the resources were written at an acceptable reading level
The Effect of Water Deficits during Flowering and Seed Production on Cultivars of Subterranean Clover and Annual Medic
In improved pastures in inland southern Australia, the persistence and growth of annual pasture legumes depends in part on their ability to produce and conserve abundant seed for regeneration and production. For near-maximum seed production in spring, adequate soil water is needed for at least 70 days in subterranean clover (Trifolium subterraneum) and medic (Medicago) species. Water deficits during spring are a common occurrence, and they appear to be increasing in frequency. The effect of relatively short periods of water deficit during reproductive development has received some attention but the findings conflict. The present experiment was conducted to examine further the responses of subterranean clover to water deficits imposed during the reproductive phase, and to compare the response of medic to that of subterranean clover. The flowering of two early strains of subterranean clover (Northam, Daglish) was synchronised with two early-flowering cultivars of annual medic (Cyprus barrel medic and Harbinger strand medic). Seed production parameters were observed on four watering treatments (nil, early, mid and late deficits during the reproductive phase). Notable differences occurred between the two genera and between the water treatments in their effect on reproductive development. A highly significant interaction favouring medic was recorded between the legumes (clover, medic) and the early deficit treatment, in that the individual seed weight of medic was slightly enhanced by water stress and clover was significantly depressed. In the mid- and late-stress treatments, a significantly lower proportion of viable seed was recorded with clover versus medic. The implications of the findings for the use of adapted annual legumes are discussed. This research was supported by a Reserve Bank Research Fellowship
Addressing obesity in the first 1000 days in high risk infants: Systematic review.
Early intervention is critical for addressing the challenge of childhood obesity. Yet many preventive interventions do not target infants most at risk of future overweight or obesity. This systematic review examines interventions delivered before 2 years that aim to ameliorate excess weight gain among infants at high risk of overweight or obesity, due to sociodemographic characteristics, parental weight or health status, infant feeding or health behaviours. We searched six databases for interventions: (a) delivered before age two, (b) specifically aimed at infants at high risk of childhood obesity and (c) that reported outcomes by weight status beyond 28 days. The search identified over 27,000 titles, and 49 papers from 38 studies met inclusion criteria: 10 antenatal interventions, 16 postnatal and 12 conducted both before and after birth. Nearly all targeted infant and/or maternal nutrition. Studies varied widely in design, obesity risk factors, outcomes and quality. Overall, nine interventions of varying quality reported some evidence of significantly improved child weight trajectory, although effects tended to diminish over time. Interventions that improved weight outcomes tended to engage parents for a longer period, and most offered health professional input and support. Two studies of limited quality reported significantly worse weight outcomes in the intervention group
Pasture legume varieties and ewe fertility
ALTHOUGH it was first thought that all varieties of subterranean clover would cause ewe infertility, research in the last 10 to 15 years has shown that varieties differ in potency.
The relative level of potency has also been shown to remain consistent for any one variety under normal conditions
The Feeding Practices and Structure Questionnaire: development and validation of age appropriate versions for infants and toddlers
Background
In order to measure and understand trajectories of parental feeding practices and their relationship with child eating and weight, it is desirable to perform assessment from infancy and across time, in age-appropriate ways. While many feeding practices questionnaires exist, none is presently available that enables tracking of feeding practices from infancy through childhood. The aim of the study was to develop a version of the Feeding Practices and Structure Questionnaire (FPSQ) for parents with infants and toddlers (< 2 years) to be used in conjunction with the original FPSQ for older children (≥2 years) to measure feeding practices related to non-responsiveness and structure across childhood.
Methods
Constructs and items for the FPSQ for infants and toddlers were derived from the existing and validated FPSQ for older children and supplemented by a review of the literature on infant feeding questionnaires. Following expert review, two versions of the questionnaire were developed, one for milk feeding parents and one for solid feeding parents. Data from two studies were combined (child ages 0–24 months) to test the derived constructs with Confirmatory Factor Analysis for the milk feeding (N = 731) and solid feeding (N = 611) versions.
Results
The milk feeding version consisted of four factors (18 items) and showed acceptable model fit and good internal reliability: ‘feeding on demand vs. feeding routine’ (α = 0.87), ‘using food to calm’ (α = 0.87), ‘persuasive feeding’ (α = 0.71), ‘parent-led feeding’ (α = 0.79). The same four factors showed acceptable model fit for the solid feeding version (21 items), likewise with good internal reliability (α = 0.74, 0.86, 0.85, 0.84 respectively). Two additional factors (13 items) were developed for the solid feeding version that appeared developmentally appropriate only for children aged 12 months or older: ‘family meal environment’ (α = 0.81) and ‘using (non-)food rewards’ (α = 0.92). The majority of factor-factor correlations were in line with those of the original FPSQ.
Conclusions
The FPSQ milk and solid feeding versions are the first measures specifically developed as precursors to the FPSQ to measure parental feeding practices in children < 2 years, particularly practices related to non-responsiveness and structure. Further validation in more diverse samples is required
One, two, or three stars? An investigation of an unusual eclipsing binary candidate undergoing dramatic period changes
We report our investigation of 1SWASP J234401.81-212229.1, a variable with a 18 461.6 s period. After identification in a 2011 search of the SuperWASP archive for main-sequence eclipsing binary candidates near the distribution's short-period limit of ~0.20 d, it was measured to be undergoing rapid period decrease in our earlier work, though later observations supported a cyclic variation in period length. Spectroscopic data obtained in 2012 with the Southern African Large Telescope did not, however, support the interpretation of the object as a normal eclipsing binary. Here, we consider three possible explanations consistent with the data: a single-star oblique rotator model in which variability results from stable cool spots on opposite magnetic poles; a two-star model in which the secondary is a brown dwarf; and a three-star model involving a low-mass eclipsing binary in a hierarchical triple system. We conclude that the latter is the most likely model
Optimising mothers’ health behaviour after hypertensive disorders of pregnancy: a qualitative study of a postnatal intervention
Background: Hypertensive disorders of pregnancy have longer-term implications, increasing women’s lifetime cardiovascular disease risk. The Blood Pressure Postpartum study is a multi-centre randomised three-arm trial of interventions, ranging in intensity and including education and lifestyle coaching, to support women to maintain or adopt healthy eating and physical activity during the first postpartum year. This qualitative sub-study nested within the main trial aimed to investigate whether and how women adopted healthy behaviours after a pregnancy complicated by a hypertensive disorder. Methods: Semi-structured telephone interviews were recorded, transcribed and analysed thematically, following Braun and Clarke principles. They explored behaviour change among new mothers following their hypertensive pregnancy, and the intervention’s effect on their capacity and motivation to pursue healthy lifestyles. Results: Thirty-four women from all three trial arms participated at 10–12 months postpartum. The three main themes were 1) Awareness of cardiovascular risk: some did not acknowledge the health risks, whereas others embraced this information. 2) Sources of motivation: while the majority were motivated to make a concerted effort to adapt their health behaviour, motivation often centred on their baby and family rather than their own needs. 3) Sustaining behaviour change with a new baby: women in the more intensive intervention arm demonstrated increased recognition of the importance of reducing cardiovascular health risks, with greater motivation and guidance to change their health behaviour. There was minimal evidence of crossover amongst groups, with women largely accepting their randomised level of intervention and not seeking additional help when randomised to minimal intervention. Conclusions: Among women participating in an early post-hypertensive disorders of pregnancy randomised controlled trial aimed at improving their cardiovascular disease risk profile, the majority recognised the future health risks and appeared motivated to improve their lifestyle, particularly women in the highest-intensity intervention group. This highlights the importance of structured support to assist women embrace healthy lifestyles especially during the challenges of new parenthood. Trial registration: The Blood Pressure Postpartum study was prospectively registered as a clinical trial with the Australian New Zealand Clinical Trials Registry (anzctr.org.au) on 13 December 2018 (registration number: ACTRN12618002004246)
COVID-19, lifestyle behaviors and mental health: A mixed methods study of women 6 months following a hypertensive pregnancy
Introduction: The COVID-19 pandemic introduced unprecedented challenges to both the physical and psychological health of postpartum women. The aim of this study was to determine how the COVID-19 pandemic affected the diet, physical activity and mental health of women 6 months following a hypertensive disorder of pregnancy. Methods: Mixed methods sub-study of the Blood Pressure Postpartum trial, which recruited women following a hypertensive disorder of pregnancy from six Sydney metropolitan hospitals. Cross sectional analysis of baseline quantitative data, collected at 6-months postpartum from March 2019-February 2022, and qualitative data analysis from semi-structured telephone interviews, was performed. Dates of COVID-19 lockdowns for Sydney, Australia were collected from government websites. Diet (vegetable, fruit, alcohol, take away intake) and physical activity (walking, vigorous activity, strength training frequency and duration) were assessed using the self-report NSW Population Health Survey. Depression and anxiety were assessed using the Edinburgh Depression Scale and GAD-7 scale, respectively. Outcome data were compared between women who completed surveys “In Lockdown” vs. “Not in Lockdown” as well as “Prior to any Lockdown” vs. “During or Following any Lockdown”. Results: Of 506 participants, 84 women completed the study surveys “In Lockdown,” and 149 completed the surveys “Prior to any Lockdown.” Thirty-four participants were interviewed. There were no statistically significant differences in diet, physical activity, depression and anxiety among women who completed the survey “In Lockdown” vs. “Not in Lockdown.” “Prior to any Lockdown,” participants were more likely to do any walking (95% vs. 89%, p = 0.017), any vigorous activity (43% vs. 30%, p = 0.006) or any strength training (44% vs. 33%, p = 0.024), spent more time doing vigorous activity (p = 0.003) and strength training (p = 0.047) and were more likely to drink alcohol at least monthly (54% vs. 38%, p < 0.001) compared with “During or Following any Lockdown.” Conclusions: Our findings suggest that the confinements of lockdown did not markedly influence the mental health, diet and physical activity behaviors of women 6 months following hypertensive pregnancy. However, physical activity levels were reduced following the emergence of COVID-19, suggesting targeted efforts may be necessary to re-engage postpartum women with exercise. Trial registration: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=376286&isReview=true, identifier: ACTRN12618002004246
Spatially and temporally distinct encoding of muscle and kinematic information in rostral and caudal primary motor cortex
The organising principle of human motor cortex does not follow an anatomical body map, but rather a distributed representational structure in which motor primitives are com- bined to produce motor outputs. Electrophysiological recordings in primates and human imaging data suggest that M1 encodes kinematic features of movements, such as joint position and velocity. However, M1 exhibits well-documented sensory responses to cu- taneous and proprioceptive stimuli, raising questions regarding the origins of kinematic motor representations: are they relevant in top-down motor control, or are they an epiphe- nomenon of bottom-up sensory feedback during movement? Here we provide evidence for spatially and temporally distinct encoding of kinematic and muscle information in human M1 during the production of a wide variety of naturalistic hand movements. Using a powerful combination of high-field fMRI and MEG, a spatial and temporal multivariate representational similarity analysis revealed encoding of kinematic information in more caudal regions of M1, over 200 ms before movement onset. In contrast, patterns of muscle activity were encoded in more rostral motor regions much later after movements began. We provide compelling evidence that top-down control of dexterous movement engages kinematic representations in caudal regions of M1 prior to movement production
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