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South Africa (SA) is a developing country with an ageing population. Adequate nutrition and physical activity (PA) protect against the loss of muscle mass and physical function, both of which are important components of sarcopenia. This study aimed to measure the prevalence of sarcopenia in older black SA women and investigate its associations with PA and protein intake.
Materials and Methods
Older black SA women (age, 68 (range; 60–85 years) n = 122) completed sociodemographic questionnaires, 24 h urine collection (estimate protein intake), venous blood (hs-C-reactive protein (hs-CRP) and ferritin), functional tests (grip strength, 3 m timed-up-and-go (TUG), 10 m walk test) and PA monitoring (activPAL). Dual-energy x-ray absorptiometry whole-body scans assessed fat and fat-free soft tissue mass (FFSTM).
According to the European Working group on Sarcopenia in Older People (EWGSOP)2, 2.5% (n = 3) had confirmed sarcopenia of a low severity based on normal physical function. Of the total cohort, 9% (n = 11) had low grip strength, 22.1% (n = 27) had a low appendicular skeletal muscle index (ASMI), and no women had low TUG (s) or gait speed (m/s). Higher ASMI was associated with lower hs-CRP (p = 0.05; Rho = -0.209) and higher ferritin (Rho = 0.252; p = 0.019), grip strength (kg, Rho = 0.223; p = 0.015), and gait speed (m/s, Rho = 0.180; p = 0.050). Protein intake suggested intake of 41.8g/day/ or 0.51 g/kg of body mass/day. Higher total protein intake (g/24h), was associated with higher FFSTM (kg) and ASMI (p < 0.001). PA outcomes were not correlated with FFSTM or ASMI (p > 0.05), however, there was a strong positive correlation of TUG (s) and gait speed (m/s) with time spent: 1) stepping per day (min) and; 2) at a high cadence (> 100 steps/min) (all p < 0.01). Daily step count was 7137 ± 3233 (mean ± Standard deviation), with 97.9 ± 38.7 min of total time spent stepping and 12.6 ± 16.8 min spent stepping at a high cadence (> 100 steps/min). Of note, 13.9% (n = 17) of women were completing > 10,000 steps/day.
Based on the EWGSOP2 criteria, there is a low prevalence of sarcopenia in older black SA women, explained by the maintenance of strength and physical function that directly related to PA, especially that performed at higher intensities. In contrast, low muscle mass was relatively prevalent (22.1%) and was associated with low dietary protein and not PA. Notably, it may be important to review the cut-points of EWGSOP2 criteria to be specific to the older SA women from disadvantaged communities.
Osteoporosis was not a public health concern in black South African (SA) women, until recently when it was reported that the prevalence of vertebral fractures was 9.1% in black compared to 5.0% in white SA women. Accordingly, this study aimed to measure bone mineral density (BMD) of older black SA women and to investigate its association with risk factors for osteoporosis, including strength, muscle and fat mass, dietary intake and objectively measured physical activity (PA).
Methods and materials
Older black SA women (age, 68 (range; 60–85 years) n = 122) completed sociodemographic and quantitative food frequency questionnaires (QFFQ), fasting venous blood samples (25-hydroxycholecalciferol: Vitamin D-25), 24 h urine collection (estimate protein intake), grip strength and PA monitoring (activPAL). Dual-energy x-ray absorptiometry (DXA) scans of the hip (femoral neck and total) and lumbar spine determined BMD and whole-body scans for fat and fat-free soft tissue mass (FFSTM). WHO classifications were used to determine osteopenia (t-score -2.5 to -1), and osteoporosis (t-score < -2.5).
At the lumbar spine 34.4% of the women (n = 42) had osteopenia and 19.7% (n = 24) had osteoporosis. Osteopenia at the left femoral neck was 32% (n = 40) and osteoporosis was 13.1% (n = 16) of participants. The total left hip BMD indicated osteopenia in 27.9% (n = 34) and osteoporosis in 13.1% (n = 16) of participants. Multinomial regression revealed no differences in age (y) or frequency of falls in the past year between all groups (p = 0.727). Compared to those with normal BMD, participants with osteoporosis at the hip neck and lumbar spine were shorter, weighed less and had a lower body mass index (BMI) (all p < 0.05). When adjusted for height, the osteoporotic group (hip neck and lumbar spine) had lower trunk fat (% whole body), FFSTM (kg) and grip strength (kg), compared to those with normal BMD (p < 0.05). Only protein intake (g; 24 h urine analyses) was lower in women with osteoporosis (all sites) compared to those with normal BMD. Fat, carbohydrate and micronutrient intakes (relative to total daily energy intake), and vitamin D concentrations were not associated with BMD (all sites). Number of daily step count and stepping time (min) were inversely associated with BMI (p < 0.05), but not with BMD (all sites; p > 0.05).
A high prevalence of osteopenia and osteoporosis was evident at the lumbar spine and hip in older black SA women. This study highlights the importance of strength, body composition, and protein intake in maintaining BMD and preventing the development of osteoporosis in older women.
Stellarator configurations with reactor relevant energetic particle losses are constructed by simultaneously optimizing for quasisymmetry and an analytically derived metric (
), which attempts to align contours of the second adiabatic invariant,
with magnetic surfaces. Results show that with this optimization scheme it is possible to generate quasihelically symmetric equilibria on the scale of ARIES-CS which completely eliminate all collisionless alpha particle losses within normalized radius
. We show that the best performance is obtained by reducing losses at the trapped–passing boundary. Energetic particle transport can be improved even when neoclassical transport, as calculated using the metric
, is degraded. Several quasihelically symmetric equilibria with different aspect ratios are presented, all with excellent energetic particle confinement.
Ion-temperature-gradient-driven (ITG) turbulence is compared for two quasi-symmetric (QS) stellarator configurations to determine the relationship between linear growth rates and nonlinear heat fluxes. We focus on the quasi-helically symmetric (QHS) stellarator HSX and the quasi-axisymmetric (QAS) stellarator NCSX. In normalized units, HSX exhibits higher growth rates than NCSX, while heat fluxes in gyro-Bohm units are lower in HSX. These results hold for simulations made with both adiabatic and kinetic electrons. The results show that HSX has a larger number of subdominant modes than NCSX and that eigenmodes are more spatially extended in HSX. We conclude that the consideration of nonlinear physics is necessary to accurately assess the heat flux due to ITG turbulence when comparing QS stellarator equilibria.
To assess type, nutrient profile and cost of food items sold by informal vendors to learners; and to determine nutrient content of corn-based processed snacks frequently sold.
Quintile 1 to 3 schools (n 36) randomly selected from six education districts; Eastern Cape, South Africa.
Informal food vendors (n 92) selling inside or immediately outside the school premises.
Food items sold at most schools were corn-based processed snacks (94 % of schools), sweets (89 %), lollipops (72 %) and biscuits (62 %). Based on the South African Nutrient Profiling model, none of these foods were profiled as healthy. Foods less commonly sold were fruits (28 % of schools) and animal-source foods; these foods were profiled as healthy. Mean (sd) energy cost (per 418 kJ (100 kcal)) was highest for animal-source foods (R2·95 (1·16)) and lowest for bread and vetkoek (R0·76 (0·21)), snacks (R0·76 (0·30)) and confectionery products (R0·70 (0·28)). The nutrient profiling score was inversely related to the energy cost of the food item (r = −0·562, P = 0·010). Compared with brand-name corn-based processed snacks, non-branded snacks had lower energy (2177 v. 2061 kJ; P = 0·031) content per 100 g. None of the brand-name samples contained sucrose; six of the nine non-branded samples contained sucrose, ranging from 4·4 to 6·2 g/100 g.
Foods mostly sold were unhealthy options, with the healthier food items being more expensive sources of energy.
Gyrokinetic simulations of drift waves in low-magnetic-shear stellarators reveal that simulation domains comprised of multiple turns can be required to properly resolve critical mode structures important in saturation dynamics. Marginally stable eigenmodes important in saturation of ion temperature gradient modes and trapped electron modes in the Helically Symmetric Experiment (HSX) stellarator are observed to have two scales, with the envelope scale determined by the properties of the local magnetic shear and an inner scale determined by the interplay between the local shear and magnetic field-line curvature. Properly resolving these modes removes spurious growth rates that arise for extended modes in zero-magnetic-shear approximations, enabling use of a zero-magnetic-shear technique with smaller simulation domains and attendant cost savings. Analysis of subdominant modes in trapped electron mode (TEM)-driven turbulence reveals that the extended marginally stable modes play an important role in the nonlinear dynamics, and suggests that the properties induced by low magnetic shear may be exploited to provide another route for turbulence saturation.
The ICDD has implemented an option in Powder Diffraction File (PDF)-4 products to calculate time-of-flight (TOF) neutron powder diffraction patterns using atomic coordinates and structure information (the PDF-4+ 2016 has 271 499 entries that contain atomic coordinates and structure data). The calculated pattern data are used to populate PDF data cells and entries that contain d-spaces and neutron intensities, and are also available for calculated on-the-fly fully digitized patterns. To extend this on-the-fly capability, we include size and strain effects that affect the profile shapes. For specific application to TOF neutron diffraction full pattern analyses, a method was developed for calculating a background function. This method treats incoherent scattering and a zeroth order approximation to thermal diffuse scattering. The results are compared with experimental data from SRM 640C (Si), SRM 676 (Al2O3 corundum), SRM 660C (LaB6), and NAC (Na2La3Al2F14) instrument standards. Finally, a comparison of the calculated total patterns (Bragg scattering plus background) scattering contrast between Nd2Ni2InD7.52 and Nd2Ni2InH7.52 shows the value of neutron scattering simulation for planning experiments.
The PDF-4+ 2016 contains 271 449 entries with atomic coordinates that can be used to calculate neutron time-of-flight (TOF) powder diffraction patterns. These diffraction patterns can all be calculated on-the-fly. Three TOF results can be realized: the live calculation of on-the fly diffraction patterns, the population of static PDF® entries, and data for search/match tables for phase identification. In connection with search/match, we have extended the development of the I/Ic formalism to include both constant wavelength (CW) and TOF neutron diffraction data. It is shown that the wavelength dependence of X-ray and CW neutron data must be factored into the behavior of I/Ic, whereas this dependence is directly incorporated into TOF data.
We have used high-resolution, HST WFC3/IR, near-infrared imaging to conduct a detailed bulge-disk decomposition of the morphologies of ≃ 200 of the most massive (M* > 1011 M⊙) galaxies at 1 < z < 3 in the CANDELS-UDS field. We find that, while such massive galaxies at low redshift are generally bulge-dominated, at redshifts 1<z<2 they are predominantly mixed bulge+disk systems, and by z > 2 they are mostly disk-dominated. Interestingly, we find that while most of the quiescent galaxies are bulge-dominated, a significant fraction (25–40%) of the most quiescent galaxies, have disk-dominated morphologies. Thus, our results suggest that the physical mechanisms which quench star-formation activity are not simply connected to those responsible for the morphological transformation of massive galaxies.
Nearby galaxies come in two flavors: red quiescent galaxies (QGs) with old stellar populations, and blue young star-forming galaxies (SFGs). This color bimodality seems to be already in place at z = 2 − 3, presenting also strong correlations with size and morphology. Surprisingly, massive QGs at higher redshifts are ~5 times smaller than local, equal mass analogs. In contrast, most of the massive SFGs at these redshifts are still relatively large disks. The strong bimodality in both SFR and sizes indicates that some SFGs must experience strong structural transformations accompanied by a rapid truncation of the star-formation to match the observed properties of QGs. Using high-resolution HST/WFC3 F160W imaging from the CANDELS survey in GOODS-S and UDS, along with multi-wavelength ancillary data, we analyze stellar masses, SFRs and sizes of a sample of massive (M* > 1010M⊙) galaxies at z = 1.4 − 3.0 to identify a population of compact SFGs with similar structural properties as compact QGs at z~2. We also find that the number density of QGs increases rapidly since z = 3. Among these, the number of compact QGs builds up first, and only at z < 1.8 we do start finding a sizable number of extended QGs. This suggests that the bulk of these galaxies are assembled at late times by both continuous migration (quenching) of non-compact SFGs and size growth of cQGs. As a result of this growth, the population of cQGs disappears by z~1. Simultaneously, we identify a population of compact SFGs (cSFGs) whose number density decreases steadily with time since z = 3.0, being almost completely absent at z < 1.4. The number of cSFGs makes up less than 20% of all massive SFGs, but they present similar number densities as cQGs down to z~2, suggesting an evolutionary link between the two populations.
An experimental X-ray powder diffraction pattern was produced and analyzed for imipenem monohydrate, an antimicrobial pharmaceutical agent. Although there are no experimental powder patterns in the ICDD PDF-4/Organics Database, there is one powder pattern calculated with single-crystal X-ray diffraction data from the Cambridge Structural Database. Here, we report the refined experimental powder diffraction data for imipenem monohydrate. These data for imipenem monohydrate are consistent with an orthorhombic crystal system having reduced unit-cell parameters of a = 8.2534(3) Å, b = 11.1293(4) Å, and c = 15.4609(6) Å. The resulting unit-cell volume, 1420.15(15) Å3, indicates four formula units per unit cell. Observed peaks are consistent with the P212121 space group.
Fish proteins have been reported to be more satiating than meat proteins. The objective was to determine the effect of different animal protein pre-meals on satiety. A total of ten intact female hounds were fed pork loin, beef loin, chicken breast, salmon fillet or pollock fillet. Each pre-meal was fed to contain 100 g protein. Blood was collected at 0, 5, 15, 30, 60, 90 and 120 min postprandially and analysed for glucose, insulin, total ghrelin, active glucagon-like peptide-1 (GLP-1) and plasma amino acids (AA). Dogs were fed 2 × metabolisable energy, 3 h following the pre-meal, and intake was determined 30, 60, 180 and 1440 min after food presentation. Glucose decreased over time (P < 0·001), but was lowest (P = 0·01) when dogs consumed pollock or chicken. Insulin increased (P < 0·0001) over time, and was greater (P = 0·09) when dogs consumed salmon. GLP-1 increased (P < 0·001) over time, and was greatest (P = 0·04) when dogs consumed beef. Ghrelin decreased (P < 0·0001) over time for all pre-meals. The tryptophan:large neutral AA ratio tended to be greater (P = 0·08) when dogs consumed pork, salmon and pollock. Different protein sources may influence blood markers in dogs, but it does not appear that fish substrates have different satiating abilities than mammalian or avian sources.
The ICDD sponsored a round robin on the quantitative Rietveld phase analysis of pharmaceuticals. 11 participating laboratories from the pharmaceutical community submitted both raw data and processed quantitative results. The purpose of the round robin was to evaluate current practices in laboratories, so procedures and methods were not specified, but they were recorded. Cluster analysis tools were applied to all the data sets and their use helped identify the root causes of several types of errors in specimen preparation, data treatment, and Rietveld analysis. The authors considered this round robin to be difficult. Sample homogeneity was an issue and molecular orientation was observed in many data sets. Each material studied has structural polymorphs so the selection of starting parameters and their refinement was nontrivial. Similar to prior round robins on inorganic materials and minerals, this round robin identified operator errors as the major contributor to poor results. Four laboratories achieved excellent results on all phases in all three samples, with accuracy within relative errors of 5% to 10%.
The biaxial stress and thermal expansion of multilayer doped-aluminosilicate environmental barrier coatings were measured in situ during cooling using microfocused high-energy X-rays in transmission. Coating stresses during cooling from 1000 °C were measured for as-sprayed and thermally cycled samples. In the as-sprayed state, tensile stresses as high as 75 MPa were measured in the doped-aluminosilicate topcoat at 375 °C, after which a drop in the stress occurred accompanied by through-thickness cracking of the two outermost layers. After thermally cycling the samples, the stress in the topcoat was reduced to approximately 50 MPa, and there was no drop in stress upon cooling. This stress reduction was attributed to a crystallographic phase transformation of the topcoat and the accompanying change in thermal expansion coefficient. The addition of a doped aluminosilicate to the mullite layer did not lower the stress in the topcoat, but may offer increased durability due to an increased compressive stress.