To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
To investigate the prevalence and socio-economic inequalities in breast milk, breast milk substitutes (BMS) and other non-human milk consumption, by children under 2 years in low- and middle-income countries (LMIC).
We analysed the prevalence of continued breast-feeding at 1 and 2 years and frequency of formula and other non-human milk consumption by age in months. Indicators were estimated through 24-h dietary recall. Absolute and relative wealth indicators were used to describe within- and between-country socio-economic inequalities.
Nationally representative surveys from 2010 onwards from eighty-six LMIC.
394 977 children aged under 2 years.
Breast-feeding declined sharply as children became older in all LMIC, especially in upper-middle-income countries. BMS consumption peaked at 6 months of age in low/lower-middle-income countries and at around 12 months in upper-middle-income countries. Irrespective of country, BMS consumption was higher in children from wealthier families, and breast-feeding in children from poorer families. Multilevel linear regression analysis showed that BMS consumption was positively associated with absolute income, and breast-feeding negatively associated. Findings for other non-human milk consumption were less straightforward. Unmeasured factors at country level explained a substantial proportion of overall variability in BMS consumption and breast-feeding.
Breast-feeding falls sharply as children become older, especially in wealthier families in upper-middle-income countries; this same group also consumes more BMS at any age. Country-level factors play an important role in explaining BMS consumption by all family wealth groups, suggesting that BMS marketing at national level might be partly responsible for the observed differences.
Bemisia tabaci (Gennadius) represents a relatively large cryptic species complex. Australia has at least two native populations of B. tabaci sensu lato and these were first found on different host plants in different parts of Australia. The species status of these populations has not been resolved, although their mitochondrial sequences differ by 3.82–4.20%. We addressed the question of whether these AUSI and AUSII B. tabaci populations are distinct species. We used reciprocal cross-mating tests to establish whether the insects from these different populations recognize one another as potential mating partners. The results show that the two native Australian populations of B. tabaci have a mating sequence with four phases, each of which is described. Not all pairs in the control crosses mated and the frequency of mating differed across them. Some pairs in the AUSI-M × AUSII-F did mate (15%) and did produce female progeny, but the frequency was extremely low relative to controls. Microsatellite genotyping of the female progeny produced in the crosses showed these matings were successful. None of the AUSII-M × AUSI-F crosses mated although some of the males did search for females. These results demonstrate the critical role of the mate recognition process and the need to assess this directly in cross-mating tests if the species status of different populations is to be tested realistically. In short, AUSI and AUSII B. tabaci populations are distinct species because the individual males and females do not recognize individuals of the alternative population as potential mating partners.
There have been few studies realized that evaluate the effects of adopting
different nutritional systems in more than one phase of cattle production on
carcass and meat characteristics. This study was realized to evaluate carcass
and meat characteristics from bulls submitted to different nutritional systems
during two production phases. The experiment was conducted at
Figueira’s farm during two production phases: I (cow–calf)
– 80 calves (99.6±2.72 days of age and
109.7±2.99 kg of BW) with their mothers were randomly assigned into
two supplemental diets: cow–calf mineral supplement
(n=40) or cow–calf creep-feeding
(n=40); II (stocker) – the same 80
calves (201.2±2.11 days of age and 190.2±3.37 kg of BW)
were redistributed into two production systems: stocker pasture
(n=40) or stocker feedlot (SF;
n=40). After, all 80 animals were kept on a pasture
system (III) for 290 days, and then finished in a feedlot system (IV) for more
33 days. Then, they were slaughtered at an average 764.2±3.06 days of
age and at 499.2±3.33 kg of final BW. After slaughter, the average
daily gain was calculated, and the carcass and meat characteristics were
measured. The statistical model design used was completely randomized in a
2×2 factorial arrangement (two treatment groups on
cow–calf phase and two treatment groups on stocker phase). The single
effects between the groups in each phase and the interactions between both
phases (cow–calf v. stocker) were analyzed. The
results were compared by Fisher’s test, using the R statistical
software. A cow–calf by stocker phases interaction occurred for
carcass conformation and fiber diameter. For single effects, the greatest
influences observed were in the stocker phase. The feedlot group was slaughtered
17 days earlier, with greater final BW (3.8%), hot carcass weight
(5.7%), average daily gain (6.9%), dressing percentage
(1.8%), carcass length (1.8%), carcass width
(1.5%), longissimus muscle area (4.8%)
and muscle depth (2.3%) than pasture group. The SF group also had
influence on fat color; showing higher L* and lower
b* values. These results reveal that bulls
reared in feedlot at the stocker phase have higher muscle development and that
the stocker phase has the greatest potential to influence carcass
characteristics and meat quality.
Persistent infection with high-risk human papillomavirus (HPV) is the main cause of cervical cancer and the prevalence of HPV types varies depending on the geographic region. Therefore, this study assessed the prevalence of HPV types in women with cervical lesions from Sergipe state, Northeastern Brazil. A cross-sectional study was conducted in women with cervical lesions from March to December 2014. These lesions were investigated by PCR and HPV types were identified by DNA sequencing. 432 patients were included, of which 337 patients tested positive for HPV. Eighteen different HPV types were detected, and high-risk HPV types were detected in 69.2%. HPV 16 (63.4%) was the most prevalent HPV type found, followed by HPV 66 (4.6%), HPV 18 (1.6%) and HPV 45 (1.4%). These results highlight the importance of the high prevalence of HPV 66, which is a possibly carcinogenic virus type not covered by the available vaccines. The prevalence of HPV 16 was high in the studied population, reaffirming the importance of young vaccination. However, the high prevalence of HPV 66 found in this study shows the importance of monitoring the diversity of HPV types in different populations and geographic regions to better understand the impacts of current HPV vaccines.
The aim of this study was to evaluate the association of dietary patterns (DP) with maternal adiposity indicators, leptin, adiponectin and insulin concentrations during pregnancy. A prospective cohort of pregnant women followed up at the 5th–13th, 20th –26th and 30th–36th gestational weeks and 30–40 d postpartum was conducted in Rio de Janeiro. A FFQ was administered in the third trimester (30th–36th gestational weeks). The reduced rank regression procedure was used to identify DP that explain response variables (dietary fibre and total fat) related to indicators of maternal adiposity (postpartum weight retention and gestational weight gain (GWG) adequacy), and plasma leptin, adiponectin and insulin concentrations. The associations between tertiles of DP and the outcomes were determined using logistic regression or longitudinal linear mixed-effect regression models. The mean daily energy intake during pregnancy was 10 104 (sd 3234) kJ (2415 (sd 773) kcal), and GWG was 11·9 (sd 4·2) kg. In all, 40 % of women presented pre-gestational overweight/obesity. Excessive GWG occurred in 34·7 % of pregnant women and 56·6 % were overweight/obese at postpartum. The ‘common-Brazilian’ DP (characterised by higher intake of beans, rice and lower intake of fast food/snacks, candies/table sugar and processed meats/bacon) was positively associated with adiponectin (β=1·07; 95 % CI 0·17, 1·98). The ‘Western’ DP (characterised by higher intake of fast food/snacks and processed meat/bacon and lower intake of noodles/pasta/roots/tubers and sodas) was negatively associated with adiponectin (β=−1·11; 95 % CI −2·00, −0·22) and positively associated with leptin concentrations (β=64·9; 95 % CI 22·8, 107·0) throughout pregnancy. It may be suggested that the ‘common-Brazilian’ is a healthy DP and beneficial for serum concentrations of adiponectin and leptin.
We performed two different approaches (broth enrichment step prior to culture (BEC) and PCR (BEPCR)) for detecting Streptococcus pneumoniae from nasopharyngeal specimens collected from 242 children aged <6 years attending one hospital (n = 140) and one childcare centre (n = 102) in a major urban area in Brazil. These specimens were collected immediately before the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) and the 13-valent vaccine (PCV13) for routine use in Brazil. Results were compared with previous findings obtained with direct culture (DC) on a selective medium. Colonisation prevalence was 58·3% (n = 141), being higher among children attending the childcare centre (62·7% vs. 55%). The culture-based methods (DC and BEC) enabled the detection of S. pneumoniae in 119 (49·2%) and 115 (47·5%) children, respectively. The PCR-based method (BEPCR) was more sensitive and 137 (56·6%) carriers were identified. Twenty-six serogroups/serotypes were identified, predominantly 6B, 19F, 14, 6A, 15C and 23F. Multiple colonisation was observed in 13 (5·4%) children. The estimated serotypes coverage of available PCVs was 40·4% for the 10-valent (included in the Brazilian immunisation programme) and 55·8% for the 13-valent (only available in private clinics). The use of robust approaches to obtain a more realistic insight about the asymptomatic carrier status is of paramount importance to estimate and assess the impact of vaccine implementation. The combination between culture-based and molecular methods constitutes a suitable strategy.
A turbulent boundary layer developed over a herringbone patterned riblet surface is investigated using stereoscopic particle image velocimetry in the cross-stream plane at
. The three velocity components resulting from this experiment reveal a pronounced spanwise periodicity in all single-point velocity statistics. Consistent with previous hot-wire studies over similar-type riblets, we observe a weak time-average secondary flow in the form of
-filling streamwise vortices. The observed differences in the surface and secondary flow characteristics, compared to other heterogeneous-roughness studies, may suggest that different mechanisms are responsible for the flow modifications in this case. Observations of instantaneous velocity fields reveal modified and rearranged turbulence structures. The instantaneous snapshots also suggest that the time-average secondary flow may be an artefact arising from superpositions of much stronger instantaneous turbulent events enhanced by the surface texture. In addition, the observed instantaneous secondary motions seem to have promoted a free-stream-engulfing behaviour in the outer layer, which would indicate an increase turbulent/non-turbulent flow mixing. It is overall demonstrated that the presence of large-scale directionality in transitional surface roughness can cause a modification throughout the entire boundary layer, even when the roughness height is 0.5 % of the layer thickness.
There are still uncertainties on the psychometric validity of the DSM-5 attention deficit hyperactivity disorder (ADHD) criteria for its use in the adult population. We aim to describe the adult ADHD phenotype, to test the psychometric properties of the DSM-5 ADHD criteria, and to calculate the resulting prevalence in a population-based sample in their thirties.
A cross-sectional evaluation using the DSM-5 ADHD criteria was carried out in 3574 individuals from the 1982 Pelotas Birth Cohort. Through receiver operator curve, latent and regression analyses, we obtained parameters on construct and discriminant validity. Still, prevalence rates were calculated for different sets of criteria.
The latent analysis suggested that the adult ADHD phenotype is constituted mainly by inattentive symptoms. Also, inattention symptoms were the symptoms most associated with impairment. The best cut-off for diagnosis was four symptoms, but sensitivity and specificity for this cut-off was low. ADHD prevalence rates were 2.1% for DSM-5 ADHD criteria and 5.8% for ADHD disregarding age-of-onset criterion.
The bi-dimensional ADHD structure proposed by the DSM demonstrated both construct and discriminant validity problems when used in the adult population, since inattention is a much more relevant feature in the adult phenotype. The use of the DSM-5 criteria results in a higher prevalence of ADHD when compared to those obtained by DSM-IV, and prevalence would increase almost threefold when considering current ADHD syndrome. These findings suggest a need for further refinement of the criteria for its use in the adult population.
This study aimed to assess the contribution of hosts characteristics (rodents and marsupials) in the organization of ectoparasite communities present in woodland patches in western central Brazil. We verified the effect of host species, sex, body mass and vertical strata in addition to the role of seasonality on the ectoparasite composition, richness and abundance. The total sampling effort was 22 032 trap-nights equally distributed in 54 woodland patches. Variance partition and principal coordinate analysis were used to verify the existence of significant relationships between response variables and predictors. As expected, host species was the most important variable in ectoparasite community assembly. The composition, richness and abundance of mites and lice were highly influenced by host species, although higher for mites than for lice. Host body mass had a determining role on the richness and abundance of tick species. Vertical stratification and seasonality had weak influence, while the sex of the host had no influence on the organization of these communities. The results are closely related to the evolutionary characteristics of the species involved, as well as with local environmental characteristics of the study area.
One of the most important parts of a hybrid reactor is the cladding because it should withstand high temperatures, neutrons with high energy, high neutron flux, as well as provide the first security contention. Besides, the material should have good mechanical properties to remove the heat. Although, the cladding material choice will have a great influence on criticality calculations. In previous works on ADS there is no cladding used, therefore in this paper it is tested different cladding materials based on SS-316, ODS, T91 and 15-15Ti used in nuclear reactors, to study the variations on the fuel depletion and variations on the neutronic parameters. The results using the cladding are compared with the one obtained without using it. The best material choice is based on the neutronic parameters that presents the closest behavior to the ADS simulated without clad.
Episodes of depression and anxiety (D&A) during the transition from late adolescence to adulthood, particularly when persistent, are predictive of long-term disorders and associated public health burden. Understanding risk factors at this time is important to guide intervention. The current objective was to investigate the associations between maternal symptoms of D&A with offspring symptoms during their transition to adulthood.
Data from a large population-based birth cohort study, in South Brazil, were used. Prospective associations between maternal D&A and offspring risk of these symptoms during the transition to adulthood (18/19, 24 and 30 years) were estimated.
Maternal D&A in adolescence was associated with offspring symptoms across the transition to adulthood, associations were consistently stronger for females than for males. Daughters whose mothers reported D&A were 4.6 times (95% confidence interval 2.71–7.84) as likely to report D&A at all three time-points, than daughters of symptom-free mothers.
Maternal D&A is associated with persistent D&A during the daughter's transition to adulthood. Intervention strategies should consider the mother's mental health.
In traditional transit timing variations (TTVs) analysis of multi-planetary systems, the individual TTVs are first derived from transit fitting and later modelled using n-body dynamic simulations to constrain planetary masses. We show that fitting simultaneously the transit light curves with the system dynamics (photo-dynamical model) increases the precision of the TTV measurements and helps constrain the system architecture. We exemplify the advantages of applying this photo-dynamical model to a multi-planetary system found in K2 data very close to 3:2 mean motion resonance, K2-19. In this case the period of the larger TTV variations (libration period) is much longer (>1.5 years) than the duration of the K2 observations (80 days). However, our method allows to detect the short period TTVs produced by the orbital conjunctions between the planets that in turn permits to uniquely characterise the system. Therefore, our method can be used to constrain the masses of near-resonant systems even when the full libration curve is not observed.
Much is known about national trends in child undernutrition, but there is little information on how socio-economic inequalities are evolving over time. We aimed to assess socio-economic inequalities in stunting prevalence over time.
We selected nationally representative surveys carried out since the mid-1990s for which information was available on asset indices and on child anthropometry. We identified twenty-five countries that had at least two surveys over an interval of 10 years or more, totalling eighty-seven surveys. Stunting prevalence was calculated according to wealth quintiles. Absolute and relative inequalities were calculated and time trends were obtained by regression.
Nationally representative household surveys from twenty-five low- and middle-income countries.
Children <5 years of age.
National prevalence declined significantly in twenty-two of the twenty-five countries. In eighteen out of twenty-five countries, relative reductions were higher among the rich than among the poor. Overall, there was no indication that inequalities improved. Striking examples are Nepal, with a 17·0 percentage points decline in stunting per decade, but where inequalities increased sharply; and Brazil, where stunting fell by 6·7 percentage points and inequalities were all but eliminated.
Global progress in reducing stunting has not been accompanied by improved equity, but countries varied markedly in how successful they were in reducing prevalence among the poorest children. It is important to document how some countries were able to reduce inequalities, so that these lessons can be used to foster global progress, particularly in light of the increased importance of within-country inequalities in the post-2015 agenda.
The aim of the present study was to compare BMI and anthropometric indicators of abdominal obesity in Brazilian adolescents from public schools between 2003 and 2008.
A comparison of anthropometric indicators in adolescents was done based on two cross-sectional surveys conducted in 2003 (n 530) and in 2008 (n 498). BMI (= weight/height2), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were evaluated. The age-adjusted means were compared between the two studies by linear regression and the percentile values were compared by quantile regression. A P value <0·05 was adopted for statistical significance.
Metropolitan area of Rio de Janeiro, Brazil.
Two probabilistic samples of students aged 15–19 years old, from public schools.
There was a decrease in boys’ mean WC (72·9 cm v. 70·9 cm, P = 0·01) and an increase in girls’ mean BMI (21·1 kg/m2v. 22·0 kg/m2, P = 0·03). Among boys, the WC, HC and WHtR percentiles were lower whereas the WHR percentiles were higher in 2008 than in 2003. Among girls, the percentiles of all measures were higher in 2008, except for WHR.
Anthropometric measures among boys tended to decrease, while among girls there was a tendency to increase from 2003 to 2008, indicating an important gender effect and a higher morbidity risk associated with excess body fat in girls. The school setting offers opportunities for interventions to address this situation.
Some recent observations seem to disagree with hierarchical theories of galaxy formation on the role of major mergers in a late build-up of massive early-type galaxies. We re-address this question by analysing the morphology, structural distortion level, and star formation enhancement of a sample of massive galaxies (M* > 5 × 1010M⊙) lying on the Red Sequence and its surroundings at 0.3 < z < 1.5. We have used an initial sample of ~1800 sources with Ks < 20.5 mag over an area ~155 arcmin2 on the Groth Strip, combining data from the Rainbow Extragalactic Database and the GOYA Survey. Red galaxy classes that can be directly associated to intermediate stages of major mergers and to their final products have been defined. For the first time we report observationally the existence of a dominant evolutionary path among massive red galaxies at 0.6 < z < 1.5, consisting in the conversion of irregular disks into irregular spheroids, and of these ones into regular spheroids. This result points to: 1) the massive red regular galaxies at low redshifts derive from the irregular ones populating the Red Sequence and its neighbourhood at earlier epochs up to z ~ 1.5; 2) the progenitors of the bulk of present-day massive red regular galaxies have been blue disks that have migrated to the Red Sequence majoritarily through major mergers at 0.6 < z < 1.2 (these mergers thus starting at z ~ 1.5); 3) the formation of E-S0's that end up with M* > 1011M⊙ at z = 0 through gas-rich major mergers has frozen since z ~ 0.6. Our results support that major mergers have played the dominant role in the definitive build-up of present-day E-S0's with M* > 1011M⊙ at 0.6 < z < 1.2, in good agreement with the hierarchical scenario proposed in the Eliche-Moral et al. (2010a) model (see also Eliche-Moral et al. 2010b). This study is published in Prieto et al. (2012).
Supported by the Spanish Ministry of Science and Innovation (MICINN) under projects AYA2009-10368, AYA2006-12955, AYA2010-21887-C04-04, and AYA2009-11137, by the Madrid Regional Government through the AstroMadrid Project (CAM S2009/ESP-1496), and by the Spanish MICINN under the Consolider-Ingenio 2010 Program grant CSD2006-00070: “First Science with the GTC” (http://www.iac.es/consolider-ingenio-gtc/). S. D. H. & G.
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.
Accretion of minor satellites has been postulated as the most likely mechanism to explain the significant size evolution of massive galaxies over cosmic time. A direct way of probing this scenario is to measure the frequency of satellites around massive galaxies at different redshifts. Here we present our study of satellites around massive galaxies (Mstar ~ 1011 M⊙) up to z ~ 2. We find (Fig. 1) that the fraction of massive galaxies with satellites down to 1:10 mass ratio is ~15% (~30% down to 1:100), not varying with redshift (Mármol-Queraltó et al., (2012)). We also find that our satellites are younger than their central galaxies at low z (Mármol-Queraltó et al., 2013). Then, if minor merging is acting to form massive galaxies, their ourtskirts should be younger than their cores. The challenge to find this age gradient in nearby massive galaxies is opened.
To investigate the association of family income at birth with BMI among young adults who have been followed since birth.
A birth cohort study.
In 1982, all children born in Pelotas, southern Brazil, were included in a perinatal survey and visited at ages 1, 2, 4, 15, 18–19 and 23 years.
Cohort members (n 4297) were traced and interviewed in 2004–2005. In all follow-ups, participants were weighed and measured, and BMI and prevalence of obesity were calculated for each age. Family income was obtained in minimum wages in 1982 and as a continuous variable, in reais, in later follow-ups. Skin colour was self-reported in 2004–2005.
Mean BMI and prevalence of obesity differed between males and females. In males, a direct relationship was found throughout life and among females this relationship was modified by age. During childhood, BMI was higher among girls from higher income groups and this association was inversed at age 23 years. At this same age, mean BMI among black women was 1·3 kg/m2 higher than among white women, even after adjustment for current family income.
The findings show in men that the relationship between income and BMI is similar to that seen in less developed areas, whereas among adult women the relationship is similar to that observed in developed countries. In addition to the effect of socio-economic status, skin colour also has an influence on the BMI of adult women.