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Folic acid (FA) supplementation is recommended periconceptionally for the prevention of neural tube defects. Limited data are available on the folate status of New Zealand (NZ) pregnant women and its association with FA supplementation intake. Objectives of this study were to examine the relationship between plasma folate (PF) concentrations and reported FA supplement use at 15±1 weeks’ gestation, and to explore sociodemographic and lifestyle factors associated with PF. We used data and blood samples from NZ participants of the Screening for Pregnancy Endpoints (SCOPE) international pregnancy cohort study. Healthy nulliparous women with singleton pregnancy (n = 1921) were interviewed and blood samples collected. PF was analysed via microbiological assay. Seventy-three percent of participants reported taking an FA supplement at 15±1 weeks’ gestation - of these, 79% were taking FA as part of or alongside a multivitamin supplement. Fifty-six percent of FA supplement users reported consuming a daily dose of ≥800µg; 39% reported taking less than 400µg/day. Mean (±SE) PF was significantly higher in women reporting FAS (54.6 ±1.5nmol/L) vs no FAS (35.1 ±1.6 nmol/L) (p<0.0001). Reported daily FA supplement dose and PF were significantly positively correlated (r=0.41; p<0.05). Younger maternal age, Pacific and Māori ethnicity and obesity were negatively associated with PF levels; vegetarianism was positively associated with PF. Reported FA supplement dose was significantly associated with PF after adjustment for sociodemographic, lifestyle confounders and multivitamin intake. The relationship observed between FA supplement intake and PF demonstrates that self-reported intake is a reliable proxy for FA supplement use in this study population.
To examine the relationship between protein intake and the risk of incident premenstrual syndrome (PMS).
Nested case–control study. FFQ were completed every 4 years during follow-up. Our main analysis assessed protein intake 2–4 years before PMS diagnosis (for cases) or reference year (for controls). Baseline (1991) protein intake was also assessed.
Nurses’ Health Study II (NHS2), a large prospective cohort study of registered female nurses in the USA.
Participants were premenopausal women between the ages of 27 and 44 years (mean: 34 years), without diagnosis of PMS at baseline, without a history of cancer, endometriosis, infertility, irregular menstrual cycles or hysterectomy. Incident cases of PMS (n 1234) were identified by self-reported diagnosis during 14 years of follow-up and validated by questionnaire. Controls (n 2426) were women who did not report a diagnosis of PMS during follow-up and confirmed experiencing minimal premenstrual symptoms.
In logistic regression models adjusting for smoking, BMI, B-vitamins and other factors, total protein intake was not associated with PMS development. For example, the OR for women with the highest intake of total protein 2–4 years before their reference year (median: 103·6 g/d) v. those with the lowest (median: 66·6 g/d) was 0·94 (95 % CI 0·70, 1·27). Additionally, intakes of specific protein sources and amino acids were not associated with PMS. Furthermore, results substituting carbohydrates and fats for protein were also null.
Overall, protein consumption was not associated with risk of developing PMS.
In addition to being associated with a higher risk of complications during pregnancy, twinning may also be a proxy for altered hormonal exposure for mothers and twin offspring, with implications for their health later in life. We compared maternal and fetal steroid hormone and insulin-like growth factor concentrations between singleton (n=62) and twin (n=41) pregnancies. Maternal concentrations of androgens, estrogens, insulin-like growth factor (IGF)-1, IGF-binding protein (BP)-3 and prolactin were quantified during the third trimester and at delivery, as well as in the fetal circulation at birth. Geometric means accounting for gestational age were calculated for hormone concentrations and compared between matched twin and singleton pregnancies. Most maternal hormone concentrations were modestly higher in twin than in singleton pregnancies in the third trimester (ranging from 8.3% for IGF-1 to 17.1% for estradiol) and at delivery (ranging from 11.1% for IGFBP-3 to 15.2% for estriol). Cord serum hormones were generally similar in twin and singleton pregnancies, except for IGFBP-3, which was 200% lower in twins. The modest differences in maternal hormones in late gestation seem unlikely to explain alterations in hormonally related disease risk in mothers of twins compared with singletons. The large deficit of IGFBP-3 in the fetal circulation of twins at birth may allow for sufficient concentrations of IGF-2 for growth and development in an environment of shared nutritional resources.
Approximately 8–20 % of reproductive-aged women experience premenstrual syndrome (PMS), substantially impacting quality of life. Women with PMS are encouraged to reduce fat intake to alleviate symptoms; however, its role in PMS development is unclear. We evaluated the association between dietary fat intake and PMS development among a subset of the prospective Nurses’ Health Study II cohort. We compared 1257 women reporting clinician-diagnosed PMS, confirmed by premenstrual symptom questionnaire and 2463 matched controls with no or minimal premenstrual symptoms. Intakes of total fat, subtypes and fatty acids were assessed via FFQ. After adjustment for age, BMI, smoking, Ca and other factors, intakes of total fat, MUFA, PUFA and trans-fat measured 2–4 years before were not associated with PMS. High SFA intake was associated with lower PMS risk (relative risk (RR) quintile 5 (median=28·1 g/d) v. quintile 1 (median=15·1 g/d)=0·75; 95 % CI 0·58, 0·98; Ptrend=0·07). This association was largely attributable to stearic acid intake, with women in the highest quintile (median=7·4 g/d) having a RR of 0·75 v. those with the lowest intake (median=3·7 g/d) (95 % CI 0·57, 0·97; Ptrend=0·03). Individual PUFA and MUFA, including n-3 fatty acids, were not associated with risk. Overall, fat intake was not associated with higher PMS risk. High intake of stearic acid may be associated with a lower risk of developing PMS. Additional prospective research is needed to confirm this finding.
Recent issues of Antiquity have seen much discussion on the topic of Carthaginian infant sacrifice: was it a Graeco-Roman fiction or did it really happen? There are strongly held opinions on both sides of the argument, with much resting on the age profile of the children interred at the cemetery known as the Carthage Tophet. Here, the authors respond to claims by Smith et al. (2011, 2013) that their ageing of the infants and children was incorrect, and so also by extension was their interpretation that not all interments at the Tophet were the result of sacrifice.
We present the KMOS (K-band Multi-Object Spectrograph) Cluster and VIRIAL (VLT IRIFU Absorption Line) Guaranteed Time Observation (GTO) programs. KMOS provides 24 arms each feeding an integral field unit (14×14 spaxels of 0.2″ pixels) for IZ, YJ, H and K band near infrared (NIR) medium resolution spectroscopy (R ∼ 3500). Targets are selected from a 7.2′ diameter patrol field. Ultra-deep spectroscopy of ∼ 80 early-type cluster galaxies (∼ 20hr on source) and ∼ 200 (∼ 10hr on source) early-type field galaxies at 1 < z < 2 will dramatically improve the situation at z > 1 for which measurements of stellar velocity dispersions and absorption indices are limited to a few, often relatively young passively evolving galaxies (e.g. Bezanson 2013). In ESO Periods P92 and P93, 15 nights worth of data has been collected for KMOS-Clusters and 6 nights for VIRIAL: this will be supplemented with more data in upcoming semesters. All galaxies have multiband HST imaging including existing or upcoming WFC3 IR imaging, providing stellar mass maps and sizes. Combined with our dispersion measurements, this will allow us to examine the fundamental plane and the dynamical mass of a large sample of z > 1 galaxies for the first time, for both cluster and field galaxies.
KMOS is a cryogenic infrared spectrograph fed by twentyfour deployable integral field units that patrol a 7.2 arcminute diameter field of view at the Nasmyth focus of the ESO VLT. It is well suited to the study of galaxy clusters at 1 < z < 2 where the well understood features in the restframe V-band are shifted into the KMOS spectral bands. Coupled with HST imagining, KMOS offers a window on the critical epoch for galaxy evolution, 7-10 Gyrs ago, when the key properties of cluster galaxies were established. We aim to investigate the size, mass, morphology and star formation history of galaxies in the clusters. Here we describe the instrument, discuss the status of the observations and report some preliminary results.
To evaluate the impact of a mandatory bread fortification programme on estimated iodine intakes of childbearing women and to describe the extent to which uptake of a maternal iodine supplement recommendation is associated with sociodemographic characteristics.
A postpartum survey was conducted using a self-administered questionnaire. Details on pre- and post-conceptional supplement use, bread intake, iodized salt use and maternal sociodemographic and obstetric characteristics were obtained.
Eleven maternity wards and hospitals located across New Zealand.
Seven hundred and twenty-three postpartum New Zealand women.
Mean iodine intake from fortified bread was 37 μg/d prior to conception. Younger women, women with higher parity, single women and those with unplanned pregnancies were less likely to meet the pregnancy Estimated Average Requirement (EAR) for iodine (all P ≤ 0·022). Although not statistically significant for all months of pregnancy, women with less education and income were less likely to meet the EAR (P ≤ 0·11 and P ≤ 0·2 for all months, respectively) and indigenous Māori women and Pacific women were less likely than New Zealand Europeans to meet the EAR (P ≤ 0·17 and P ≤ 0·051 for all months, respectively). During pregnancy, iodine-containing supplement uptake at the recommended level (150 μg/d) was non-uniform across sociodemographic subgroups, with the most disadvantaged women benefiting the least from this public health policy.
The disparities in supplement uptake noted here highlight the need for prioritizing further efforts towards universal salt iodization, such as the mandatory fortification of additional processed foods with iodized salt.
During strombolian eruptions, large bubbles of exsolved magmatic gas, with sizes of meters or more, intermittently burst at the magma surface, spraying magma clots over distances of tens to hundreds of meters. This style of activity results from low magma viscosities allowing gas bubbles to move through the liquid magma phase. Relatively small bubbles rise and coalesce into bubbles with diameters similar to that of the conduit, at which point they are called gas slugs. This coalescence is responsible for converting the continuous degassing processes at depth into the observed intermittent surface activity, and may be controlled by the decompression expansion of the bubbles or by portions of non-vertical conduit geometry. Models of strombolian systems cover the bubble coalescence phase (slug generation), the slug ascent, and finally slug burst and the ejection of pyroclasts. A wide range of geophysical measurements, notably from Stromboli and Erebus volcanoes, are available to test these subsurface models. Nevertheless, key questions, such as the degree to which the activity is controlled by the geometry of the conduit, remain.
At volcanoes with relatively low-viscosity magmas such as basalt and basaltic andesite, large bubbles (with sizes of meters or greater) of exsolved gas can ascend rapidly through the melt and burst energetically at the surface, producing sprays of molten pyroclasts (Fig. 6.1). This type of intermittent explosion, in which a limited amount of magma is erupted with a relatively significant mass of gas, is known as “strombolian” after the characteristic activity at Stromboli volcano, where several such events usually occur every hour.
The global carbon (C) cycle can be characterized in multiple ways. In Chapter 2, C pools, fluxes, and mechanisms controlling the size and rates of pools and fluxes of C are reviewed as a whole. In this chapter, the primary concern is with annual net exchanges of C between the atmosphere and three other major C pools – land, oceans, and fossil fuels – with an emphasis on the role that land use and land-use change have in adding C to or removing it from the atmosphere. The net exchanges are important because they determine the rate at which carbon dioxide (CO2) accumulates in the atmosphere and, hence, the rate and extent of climate change.
The dominant feature of the annual net global emissions of C from land use and land-use change is the gradually increasing trend over the past 155 years (1850 to 2005; Figure 3.1) and probably much longer (Kaplan, Krumhardt, and Zimmermann 2009). This trend, however, is misleading for at least two reasons. First, the trend is not representative of any specific geographic region; because the trend is global, it obscures regional trends. The gradually increasing trend is the result of recently decreasing net emissions and increasing sinks in developed countries (in temperate and boreal zones) offsetting more rapidly increasing net emissions from developing countries in the tropics (Figure 3.2). Second, the net emissions hide the much larger gross sources and sinks of C from land use and land-use change (Figure 3.3). More C is emitted to and removed from the atmosphere each year as a direct result of human activity than is revealed by estimates of the net flux.
Writing about the ‘Tophet’, a children's cemetery in Carthage, Smith et al. argued in these pages that the age distribution of the children peaks at 1–1.49 months, supplying “another link in the chain of evidence—funerary practices, texts, iconography—that supports the interpretation of the Phoenician Tophets as ritual sites set aside for infant sacrifice” (2011: 871). In this they had challenged Jeffrey Schwartz and colleagues, who previously argued (2010) that “skeletal remains from Punic Carthage do not support systematic sacrifice of infants”. Here Schwartz et al. restate their position for Antiquity readers, showing that the verdict on the Phoenician practice of child sacrifice is, at best, not proven.
Public health recommendations do not distinguish between vitamin D2 and vitamin D3, yet disagreement exists on whether these two forms should be considered equivalent. The objective of the present study was to evaluate the effect of a daily physiological dose of vitamin D2 or vitamin D3 on 25-hydroxyvitamin D (25(OH)D) status over the winter months in healthy adults living in Dunedin, New Zealand (latitude 46°S). Participants aged 18–50 years were randomly assigned to 25 μg (1000 IU) vitamin D3 (n 32), 25 μg (1000 IU) vitamin D2 (n 31) or placebo (n 32) daily for 25 weeks beginning at the end of summer. A per-protocol approach, which included ≥ 90 % supplement compliance, was used for all analyses. Serum 25-hydroxyvitamin D3 (25(OH)D3), 25-hydroxyvitamin D2 (25(OH)D2) and parathyroid hormone (PTH) were measured at baseline and at 4, 8, 13 and 25 weeks. Geometric mean total serum 25(OH)D concentrations (sum of 25(OH)D2 and 25(OH)D3) at baseline was 80 nmol/l. After 25 weeks, participants randomised to D2 and placebo had a significant reduction in serum 25(OH)D3 concentrations over the winter months compared with vitamin D3-supplemented participants (both P< 0·001). Supplementation with vitamin D2 increased serum 25(OH)D2 but produced a 9 (95 % CI 1, 17) nmol/l greater decline in the 25(OH)D3 metabolite compared with placebo (P< 0·036). Overall, total serum 25(OH)D concentrations were 21 (95 % CI 14, 30) nmol/l lower in participants receiving vitamin D2 compared with those receiving D3 (P< 0·001), among whom total serum 25(OH)D concentrations remained unchanged. No intervention-related changes in PTH were observed. Daily supplementation of vitamin D3 was more effective than D2; however, the functional consequence of the differing metabolic response warrants further investigation.
We have grown a series of Ge and graded Si1-xGex epilayers on (100)Si substrates by MBE under different conditions. The quality of the layers has been characterized by cross-sectional TEM, Rutherford backscattering/ channeling and x-ray diffraction. This work addresses the optimization of growth temperature, (300–700°C) an evaluation of compositional grading, the effect of the incorporation of strained layer superlattice dislocation filters and post growth anneal cycles. Particular attention has been paid to grading GexSi1-x, x = 0 to 1 and the growth morphology of intermediate alloy epilayers.
It is shown that the presence of 8 × 1015 hydrogen atoms/cm2 in the CoSi2/Si (100) interface causes an increase in the Schottky barrier height of 120 meV, and that passivation of dopants in the substrate is not the cause of this change. The data is evidence that the position of the Fermi level in this interface is controlled by defect-related interface states. After hydrogenation the Schottky barrier height agrees with that predicted by theory for Fermi level pinning by virtual gap states of the silicon.
Elemental Vapor Transport Epitaxy (EVTE) is a novel technique for semiconductor manufacturing, which combines the advantages of Molecular Beam Epitaxy (MBE) and Vapor Phase Epitaxy (VPE). EVTE provides a high level of elemental flux control, scaling to large deposition areas, and elimination of elemental Ga source related oval defects. EVTE has been successfully applied to the deposition of III-V and II-VI thin films and heterostructures. Design considerations and evaluations of the novel EVTE elements: elemental flux regulating valve operating at temperatures >1250°C with demonstrated response times less than 1 second and elemental flux distribution manifold are presented. The calculated operational parameters for EVTE are in good agreement with the observed experimental results.
In this work we report on detailed temperature dependent photoluminescence measures on InGaAs/GaAs strained layer quantum well structures. Excitation energies above and below the GaAs band gap have been used in order to separate the contributions of the carrier trapping to the generation-recombination processes from the recombination mechanisms proper of the quantum wells. The results show that a decrease of the trapping efficiency contributes to the photoluminescence quenching, and suggest that the strong photoluminescence quenching observed in these structures should be mainly attributed to defects present in the quantum wells. A clear dependence of the luminescence quenching on the excitation intensity has also been found.
We report the first InSb film growth on Si by low-pressure metalorganic chemical vapor deposition. High-quality layers of InSb have been grown on Si and GaAs substrates. InSb films displayed mirror-like morphology on both substrates. X-ray full width at half maximum of 171 arcsec on GaAs and 361 arcsec on Si for a InSb layer thickness of 3.1 μm were measured. Room-temperature Hall mobilities of 67,000 and 48,000 cm2/V.s with carrier concentration of 1.5×1016 and 2.3×1016 cm−3 have been achieved for InSb films grown on GaAs and Si substrates, respectively. A 4.8 μ-thick InSb film on GaAs exhibited mobility of 76,200 cm2/Vs at 240 K.
Using current-voltage measurements and high-resolution electron microscopy (HREM), we have studied the electrical and structural properties of Ti contacts on an atomically clean n-type GaAs (110) surface. The Ti/n-GaAs diodes are formed at room temperature in ultrahigh vacuum and in situ isochronally (10 min) annealed at temperatures ranging from 200 to 450°C. We find that the Schottky barrier height of the diodes increases by ≈0.10 eV upon annealing at 200°C and remains basically stable for higher-temperature anneals. HREM investigation reveals that Ti reacts with GaAs in its as-deposited state to form an amorphous interlayer ≈1.5 nm thick. After anneals to 450°C, extensive reactions occur at the interface, resulting in the formation of a layered structure Ti/Ga3Ti2/TiAs/GaAs, with TiAs protruding into the GaAs substrate.