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 compare the prevalence of malnutrition (undernutrition and excess weight) by wealth, education level, ethnicity and urban/rural areas in Mexican children and women of reproductive age.
We compared the prevalence of overweight, obesity, wasting/underweight, stunting/short stature and anaemia by socioeconomic and ethnic indicators. For each indicator, we estimated prevalence ratios (PR) adjusted by all other socioeconomic and ethnic indicators. We analysed if results differed by urban/rural areas.
Mexican National Health and Nutrition Survey 2012.
Children <5 years, non-pregnant women 11–19 years and non-pregnant women 20–49 years (n 33 244).
In most age groups, belonging to non-indigenous households, with high wealth, high education and in urban areas were inversely associated with stunting or short stature (PR ranging from 0·40 to 0·83), and wealth and education were inversely associated with anaemia (PR ranging from 0·53 to 0·78). The prevalence of overweight was similar across subgroups among children <5 years; however, among women 11–19 years, wealth, non-indigenous household and urban areas were positively associated (PR ranging from 1·16 to 1·33); and among women 20–49 years, education was inversely associated (PR 0·83).
Socially disadvantaged populations have a higher prevalence of undernutrition, whereas the prevalence of excess weight is either equal (children <5 years), slightly lower (women 11–19 years) or even higher (women 20–49 years) with lower education. These results highlight the need for specific actions to address social inequalities in malnutrition in the Mexican population.
TwinsMX is a national twin registry in Mexico recently created with institutional support from the Universidad Nacional Autónoma de México. It aims to serve as a platform to advance epidemiological and genetic research in the country and to disentangle the genetic and environmental contributions to health and disease in the admixed Mexican population. Here, we describe our recruitment and data collection strategies and discuss both the progress to date and future directions. More information about the registry is available on our website: https://twinsmxofficial.unam.mx/ (content in Spanish).
To determine the prevalence of low scores for two neuropsychological tests with five total scores that evaluate learning and memory functions.
N = 5402 healthy adults from 11 countries in Latin America and the commonwealth of Puerto Rico were administered the Rey–Osterrieth Complex Figure (ROCF) and the Hopkins Verbal Learning Test (HVLT-R). Two-thirds of the participants were women, and the average age was 53.5 ± 20.0 years. Z-scores were calculated for ROCF Copy and Memory scores and HVLT-R Total Recall, Delayed Recall, and Recognition scores, adjusting for age, age2, sex, education, and interaction variables if significant for the given country. Each Z-score was converted to a percentile for each of the five subtest scores. Each participant was categorized based on his/her number of low scoring tests in specific percentile cutoff groups (25th, 16th, 10th, 5th, and 2nd).
Between 57.3% (El Salvador) and 64.6% (Bolivia) of the sample scored below the 25th percentile on at least one of the five scores. Between 27.1% (El Salvador) and 33.9% (Puerto Rico) scored below the 10th percentile on at least one of the five subtests. Between 5.9% (Chile, El Salvador, Peru) and 10.3% (Argentina) scored below the 2nd percentile on at least one of the five scores.
Results are consistent with other studies that found that low scores are common when multiple neuropsychological outcomes are evaluated in healthy individuals. Clinicians should consider the higher probability of low scores when evaluating learning and memory using various sets of scores to reduce false-positive diagnoses of cognitive deficits.
OBJECTIVES/SPECIFIC AIMS: The Title V Cooperative Project of the UPR-MSC and UCC has demonstrated that educational interventions in CTR are very effective in fulfilling the objective of promoting awareness, stimulate interest and increase the knowledge, skills and opportunities, to US, GS and F (participants) in CTR. METHODS/STUDY POPULATION: The training sessions (TS) offered through the Title V initiative have become an engine for the involvement in CTR for participants from higher education institutions island-wide. TS consisted of cycles –level 1 and 2–: Research Education Towards Opportunities (RETO,I,II) and Mentorship Offering Training Opportunities for Research (MOTOR,I,II), ending in the formation of the Clinical and Translational Mentoring Teams (CTMT)s, in which participants, paired by their research interests, were mentored by a well-established CT researchers in their research project, to be developed in the Intensive Development and Experiences in Advancement of Research and Increased Opportunities (IDEARIO). RESULTS/ANTICIPATED RESULTS: Up to date, 4 TS-level 1 and 2 TS-level 2 were offered. Eighty (80) participants completed level 1, distributed: 42 (52.5%) US in RETO, 21 (26.25%) GS and 17 (21.25%) F in MOTOR and 17 participants completed level 2, distributed: 4 (23.52%) US in RETO, 6 (25.29%) GS and 7 (41.17%) F in MOTOR. From which, 15, with 8 CT researchers, formed 5 CTMTs in different research areas – cardio, neuro, liver, renal, Zika–. DISCUSSION/SIGNIFICANCE OF IMPACT: US, GS and F were integrated in the active process throughout educational levels for their development in CTR.
Cryptococcal Meningitis is a fungal infectious disease of worldwide distribution, primarily associated with underlying immunosuppression conditions such as HIV infection, glucocorticoid treatment, status post organ transplantation and oncological treatments. Prevalence is particularly high in third-world countries where it constitutes one of the primary causes of central nervous system infections and may carry fatal outcomes. We present two cases of Cryptococcal Meningitis that portray the vast spectrum of clinical presentations associated with Cryptococcal Meningitis as well as relevant diagnostic and therapeutic implications.
Case study - These adult otherwise healthy patients presented at a public urban university hospital in southern Colombia. Both had an unusual clinical course and suffered fatal outcomes despite being seemingly immunocompetent at baseline. A diagnosis of hepatic cirrhosis could have been considered a cause of immunosuppression in one of the patients and the diagnostic work-up for the other patient revealed no evidence of immunological deficiency.
Cryptococcal Meningitis affecting immunocompetent individuals has been increasingly reported in recent years. Furthermore, outcomes in this population are particularly worse than those generally affected by the disease. A review of the literature related to the possible immunological mechanisms’ underlying the presented clinical course is included. We emphasize the importance of considering Cryptococcus spp. as a possible etiologic agent among differential diagnoses upon encountering suggestive meningeal conditions in immunocompetent patients.
To estimate changes in taxed and untaxed beverages by volume of beverage purchased after a sugar-sweetened beverage (SSB) tax was introduced in 2014 in Mexico.
We used household purchase data from January 2012 to December 2015. We first classified the sample into four groups based on pre-tax purchases of beverages: (i) higher purchases of taxed beverages and lower purchases of untaxed beverages (HTLU-unhealthier); (ii) higher purchases of both types of beverages (HTHU); (iii) lower purchases of taxed and untaxed beverages (LTLU); and (iv) lower purchases of taxed beverages and higher purchases of untaxed beverages (LTHU-healthier). Next, we estimated differences in purchases after the tax was implemented for each group compared with a counterfactual based on pre-tax trends using a fixed-effects model.
Areas with more than 50 000 residents in Mexico.
Households (n 6089).
The HTLU-unhealthier and HTHU groups had the largest absolute and relative reductions in taxed beverages and increased their purchases of untaxed beverages. Households with lower purchases of untaxed beverages (HTLU-unhealthier and LTLU) had the largest absolute and relative increases in untaxed beverages. We also found that among households with higher purchases of taxed beverages, the group with lowest socio-economic status had the greatest reduction in purchases of taxed beverages.
Evidence associating the SSB tax with larger reductions among high purchasers of taxed beverages prior to the tax is relevant, as higher SSB purchasers have a greater risk of obesity, diabetes and other cardiometabolic outcomes.
Childhood obesity has increased rapidly in Mexico, along with changes in the food environment. However, little is known about the dietary patterns (DP) of Mexican children. We aimed to characterize the DP of schoolchildren and to analyse their associations with sociodemographic factors.
Cross-sectional analysis. Dietary and sociodemographic information was obtained, including a single 24 h recall, socio-economic status (SES), geographic region, area of residence and ethnicity. DP were defined with cluster analysis (using k-means). Multinomial logistic regression models, adjusted for the survey design, were used to assess associations between DP and sociodemographic variables.
2012 Mexican National Health and Nutrition Survey (ENSANUT-2012).
Schoolchildren (n 2751) aged 5–11 years who participated in ENSANUT-2012.
Four DP were identified: ‘Traditional’, ‘Industrialized’, ‘Varied’ and ‘Modern’. Reported energy intake (mean (sd)) was lowest in the ‘Traditional’ and highest in the ‘Industrialized’ DP (7037 (3707) kJ/d (1682 (886) kcal/d) v. 8427 (3753) kJ/d (2014 (897) kcal/d), respectively, P<0·05). Significant differences in fat and fibre intakes were seen across DP. Non-indigenous v. indigenous children were 22·0 times (95 % CI 5·1, 93·6) more likely to have a ‘Modern’ rather than ‘Traditional’ DP. Relative likelihood of having an ‘Industrialized’ rather than ‘Traditional’ DP was 6·2 (95 % CI 3·9, 9·9) among schoolchildren from high SES v. low SES.
Among Mexican schoolchildren, DP were associated with sociodemographic variables. Non-indigenous children were significantly more likely to consume a ‘Modern’ than a ‘Traditional’ DP. Children with higher SES were more likely to have an ‘Industrialized’ pattern. It is necessary to consider dietary characteristics in the different sociodemographic strata when dietary interventions are designed.
We study ultrametric germs in one variable having an irrationally indifferent fixed point at the origin with a prescribed multiplier. We show that for many values of the multiplier, the cycles in the unit disk of the corresponding monic quadratic polynomial are ‘optimal’ in the following sense: they minimize the distance to the origin among cycles of the same minimal period of normalized germs having an irrationally indifferent fixed point at the origin with the same multiplier. We also give examples of multipliers for which the corresponding quadratic polynomial does not have optimal cycles. In those cases we exhibit a higher-degree polynomial such that all of its cycles are optimal. The proof of these results reveals a connection between the geometric location of periodic points of ultrametric power series and the lower ramification numbers of wildly ramified field automorphisms. We also give an extension of Sen’s theorem on wildly ramified field automorphisms, and a characterization of minimally ramified power series in terms of the iterative residue.
A two-dimensional global stability analysis is numerically conducted for the basic fully developed steady flow inside symmetric wavy channels. The relative amplitude of channel modulation, defined as ratio of wall modulation amplitude to mean hydraulic diameter, is fixed via the analysis at a large value of 0.15. The relative channel wavelength, defined as the ratio of wall modulation wavelength to mean hydraulic diameter, is varied between 1 and 5. An important feature of the present approach is the detailed consideration of the streamwise conditions imposed on the flow, which allows a tailored restriction of the possible disturbances by modifying the number of channel sections that set the periodicity. Stability of the base flow is determined on the basis of the spectral structure analysis conducted, possible after calculation of the complete eigenvalue spectrum and facilitated by the spectral method employed. Two different destabilization mechanisms have been identified for the geometry studied. For small relative channel wavelengths, with values below approximately 2.7, the flow is destabilized via a Hopf bifurcation produced by a Tollmien–Schlichting wave at Reynolds numbers in the approximated range from 265 to 324. For large relative channel wavelengths, with values above approximately 2.5, a pitchfork bifurcation (or a Hopf bifurcation with very small oscillation frequency), not previously reported in the literature and produced by a symmetric stationary disturbance, is found at Reynolds numbers in the approximated range from 146 to 230.
Among the many challenges to deal with, when a robot is interacting with its environment, friction at the contact surface and/or at the joints is one of the most important to be considered. In this paper we propose a control algorithm for the tracking of position and force (unconstrained orientation case only) of a manipulator end-effector that does not require the robot model for implementation. This characteristic has the advantage of making it capable to compensate friction effects without any previous estimation. Furthermore, no velocity measurements are needed, and the unit quaternion is employed for orientation control. Experimental and simulation results are provided.
To investigate the relationship between dietary patterns and self-perceived body shape silhouette and BMI in a sample of Mexican women.
A cross-sectional analysis of dietary habits from baseline data of a large cohort study (EsMaestra) conducted in 2006–2008.
The state of Veracruz, Mexico.
Mexican teachers (n 20 330) provided information on body shape silhouette at baseline, changes in body shape silhouette and BMI, as well as information on sociodemographic variables and lifestyle.
The median BMI was 26·8 kg/m2; 43 % of women were overweight and 24 % were obese. The carbohydrates, sweet drinks and refined foods pattern was associated with a greater risk of having a large silhouette and a large BMI (BMI ≥ 30·0 kg/m2v. BMI < 25·0 kg/m2; ORT1−3 = 1·86, 95 % CI 1·56, 2·22 and 1·47, 95 % CI 1·28, 1·69, respectively) with a significant trend when comparing the first and third tertiles of intake. The fruit and vegetable pattern was associated with a lower risk of having a large silhouette and a large BMI (ORT1−3 = 0·68, 95 % CI 0·57, 0·82 and ORT1−3 = 0·77, 95 % CI 0·67, 0·88, respectively) with a significant decreasing trend. Similar results were observed when change in silhouette (from 18 years of age to current silhouette) was considered.
High intakes of carbohydrates, sweet drinks and refined foods are related to larger silhouettes. Public health intervention improving access to healthy dietary guidelines, healthy food choice in the work place, promotion of physical activity and regulation of beverages with a high sugar content and of refined foods should be considered.
We show some level-2 large deviation principles for rational maps satisfying a strong form of non-uniform hyperbolicity, called ‘Topological Collet–Eckmann’. More precisely, we prove a large deviation principle for the distribution of iterated preimages, periodic points, and Birkhoff averages. For this purpose we show that each Hölder continuous potential admits a unique equilibrium state, and that the pressure function can be characterized in terms of iterated preimages, periodic points, and Birkhoff averages. Then we use a variant of a general result of Kifer.
The use of nanoparticles as carriers of photosensitizer (PS) molecules for photodynamic therapy (PDT) has attracted much interest on core-shell nanosize structures. Herein, we used a simple aqueous solution method to synthesize Fe3O4/ZnO core-shell nanoparticles. X-ray diffraction (XRD) analyses showed the presence of well defined peaks corresponding to Fe3O4 and ZnO in as-synthesized nanocrystals. Vibrating sample magnetometer (VSM) measurements showed that these nanoparticles exhibited superparamagnetic behavior of the core with no coercivity nor remanence. X-ray photoelectron spectroscopy (XPS) analyses revealed the presence of Zn1/2 and Zn3/2 species on the surface of nanocrystals. Photoluminescence measurements showed excitonic emission of ZnO co-existing with a weak and broad defect- related green emission at room temperature. The generation of singlet oxygen was monitored via the photooxidation of diphenyl-1,3-isobenzofuran (DPBF) with different light sources, followed by absorption spectroscopy at 409 nm. The capability of synthesized nanoparticles to generate singlet oxygen has also been verified.
Despite significant reductions in income poverty in recent years, under-nutrition remains widespread. Estimates published in the Lancet (Black et al. 2008) suggest that “maternal and child Under-nutrition is the underlying cause of 3.5 million deaths, 35 percent of the disease burden in children younger than 5 years, and 11 percent of total global DALYs.” Under-nutrition can be indicated both by anthropometric indices (underweight, stunting, and wasting) and by missing micronutrients in poor-quality diets.
Under-nutrition in turn has negative effects on income and on economic growth. Undernutrition leads to increased mortality and morbidity, which lead to loss of economic output and increased spending on health. Poor nutrition means that individuals are less productive (due to both physical and mental impairment), and that children benefit less from education. The 2004 Copenhagen Consensus paper on the topic discusses these mechanisms in detail (Behrman, Alderman, and Hoddinott 2004) (hereafter, BAH 2004). Reducing under-nutrition is one of the MDGs (Goal 1 aims to eradicate extreme poverty and hunger), and is also a key factor underpinning several others. Achieving goals in primary education, reducing child mortality, improving maternal health, and combating HIV/AIDS, malaria, and other diseases all depend crucially on nutrition.
There are cost-effective interventions for improving nutrition. The first section below discusses the challenge in more detail, the second describes selected priority solutions; the third section undertakes more detailed economic analysis of these solutions, and the fourth and final section discusses the implications of the analysis.
Concordance of nutritional research priorities with the related burden of disease is essential to develop cost-effective interventions to address the nutritional problems of populations. The present study aimed to evaluate whether nutrition research priorities are in agreement with the population’s nutritional problems in Latin America.
The epidemiological profile was contrasted with the research priorities and research produced by academic institutions for each country. Qualitative analysis of research production by type of contribution to problem solving was also conducted.
Nine Latin American countries.
Obesity (high body mass index (BMI)) and micronutrient deficiencies (anaemia) emerged as key problems, followed by stunting, breast-feeding/lactation and low birth weight. Wasting in children and women (low BMI) was uncommon. Concordance of ranked research priorities with the epidemiological profile of the country was generally good for nutrition-related chronic diseases, micronutrients and low birth weight, but not for undernutrition, stunting and breast-feeding. Studies on the efficacy and effectiveness of interventions were uncommon.
The present research agenda insufficiently supports the goal of public health nutrition, which is to ensure the implementation of cost-effective nutrition programmes and policies. A more rational approach to define research priorities is needed.
We introduce and study a non-uniform hyperbolicity condition for complex rational maps that does not involve a growth condition. We call this condition backward contraction. We show this condition is weaker than the Collet–Eckmann condition, and than the summability condition with exponent one. Our main result is a connecting lemma for backward-contracting rational maps, roughly saying that we can perturb a rational map to connect each critical orbit in the Julia set with an orbit that does not accumulate on critical points. The proof of this result is based on Thurston's algorithm and some rigidity properties of quasi-conformal maps. We also prove that the Lebesgue measure of the Julia set of a backward-contracting rational map is zero, when it is not the whole Riemann sphere. The basic tool of this article is sets having a Markov property for backward iterates that are holomorphic analogues of nice intervals in real one-dimensional dynamics.
To explore anthropometric indicators and mental development in very-low-income children in the second year of life.
Low-income areas (income <20th percentile) in semi-urban Mexico (defined as towns or cities with 2500–50 000 inhabitants).
Eight hundred and ninety-six children aged 12.5–23.5 months surveyed from September to December 2001.
Questionnaire survey and anthropometric survey of households. Multivariate regression models evaluated differences across age in anthropometry (height-for-age Z-score (HAZ) and weight-for-height Z-score) and cognitive function (Mental Development Index (MDI) of the Bayley Scales of Infant Development) while controlling for socio-economic and parental characteristics.
There was a significant decline in HAZ and in age-adjusted MDI score across the second year of life. Although the children showed MDI scores close to the mean, normed US values at 13–14 months, the scores were significantly lower than expected in older children (P < 0.0001), even after controlling for socio-economic status and parental characteristics. At 13–14 months, only 3% of children received scores below 70 (less than minus two standard deviations), whereas by 19–20 months, almost 17% of children were performing below this level. No socio-economic or parental characteristics were significant predictors of HAZ or MDI.
Parallel deficits are evident in both height-for-age and cognitive functioning during the second year of life in low-income Mexican infants. The consistency of these growth and development findings further stresses the need for targeted interventions to reduce the vulnerability of low-income Mexican children very early in life.