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Abstract One of the most typical dishes of traditional Mexican cuisine is pozole, made with nixtamalized maize. This dish has a special place as part of the identity of Mexican culture. However, it is time-consuming to prepare. With an increasing demand for precooked maize for pozole and the limited information on its preparation process, this study aims to assess the impact of both traditional (TN) and commercial nixtamalization (CN) on the quality of processed maize and its reception by consumers, focusing on the three most popular maize landraces used in pozole recipes. This study was carried out with the Cacahuacintle (‘CAC’), Elotes Occidentales (‘EO’) and Ancho (‘AN’) landraces, which were nixtamalized using the traditional method (only lime) and the commercial method (lime + additives) and the grain was flowered. The quality of the flowered grain was determined, and a sensory analysis consisting of magnitude of difference tests, a descriptive analysis, affective test and evaluation of consumer preferences was carried out. The ‘CAC’ landrace, when processed traditionally, yielded the highest sensory and commercial quality. The ‘EO’ landrace demanded a longer flowering time, resulting in less volume but retaining the aleurone layer. This characteristic helped preserved a portion of the anthocyanins. Consistently, maize landraces subjected to traditional nixtamalization displayed higher ratings for attributes related to masa and nejayote aroma. The ‘CAC’ landrace subjected to CN faced challenges in acceptability due to odors of acetic acid and sulfuric acid. These findings underscore the importance and advantages the TN techniques. They also emphasize the need to preserve grain quality and meeting consumer preferences when exploring alternative maize processing methods for emerging markets.

Utilizing Utah state data, the aim of this study is to examine the association between language program types programs (dual language programs [DLI], sheltered instruction [SEI], and English as a second language [ESL]) since first grade and third-grade basic literacy skills of Spanish-speaking English learners (ELs) in the United States. We employ propensity score matching (PSM) to generate matched samples using child and family factors known to be associated with children’s early literacy: child sex, immigrant status, unhoused status, special education status, child met Dynamic Indicators of Basic Early Literacy Skills (DIBELS) benchmark at start of first grade, as well as family income and parental language (DLI & ESL, n = 380; DLI & SEI, n = 380; SEI & ESL, n = 550). Regression models comparing early literacy outcomes for each matched group indicate small trends, based on effect sizes, in favor of DLI programs when compared to other program types, although differences were not statistically significant. Implications for policy and practice related bilingual education are addressed.

Abstract Fatigue is a common reason that patients seek medical care. Only a fraction of these patients meet criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). To determine if ME/CFS is just a more extreme form of fatigue, or a qualitatively different condition, we assessed whether risk factors for ME/CFS and for Severe Fatigue were similar. An email questionnaire that inquired about symptoms of Severe Fatigue and ME/CFS was completed by 41,802 US female nurses from whom detailed medical and lifestyle information had been collected since 1989: 102 met criteria for ME/CFS, 522 had Severe Fatigue, and 41,178 individuals were without significant chronic fatigue. We used Cox proportional hazards regression to estimate the Hazard Ratio (HR) of Severe Fatigue and of ME/CFS with each of several potential risk factors, according to the level of exposure to each risk factor. The risk of Severe Fatigue was significantly increased among participants who were older, had a higher BMI in adulthood, used hormone therapy, had increased alcohol intake and decreased caffeine intake. In contrast, these risk factor associations were not seen in people with ME/CFS. A self-reported past history of acute infectious mononucleosis was associated with a non-significantly increased Hazard Ratio of later ME/CFS (HR 1.77, 0.87–3.61) and, to a lesser extent, of Severe Fatigue (HR 1.28, 0.98–1.66). The different contribution of various risk factors to Severe Fatigue and ME/CFS suggests that ME/CFS has a qualitatively different underlying biology from the more common state of Severe Fatigue.

The two most important activities in maize breeding are the development of inbred lines with high values of general combining ability (GCA) and specific combining ability (SCA), and the identification of hybrids with high yield potentials. Genomic selection (GS) is a promising genomic tool to perform selection on the untested breeding material based on the genomic estimated breeding values estimated from the genomic prediction (GP). In this study, GP analyses were carried out to estimate the performance of hybrids, GCA, and SCA for grain yield (GY) in three maize line-by-tester trials, where all the material was phenotyped in 10 to 11 multiple-location trials and genotyped with a mid-density molecular marker platform. Results showed that the prediction abilities for the performance of hybrids ranged from 0.59 to 0.81 across all trials in the model including the additive effect of lines and testers. In the model including both additive and non-additive effects, the prediction abilities for the performance of hybrids were improved and ranged from 0.64 to 0.86 across all trials. The prediction abilities of the GCA for GY were low, ranging between − 0.14 and 0.13 across all trials in the model including only inbred lines; the prediction abilities of the GCA for GY were improved and ranged from 0.49 to 0.55 across all trials in the model including both inbred lines and testers, while the prediction abilities of the SCA for GY were negative across all trials. The prediction abilities for GY between testers varied from − 0.66 to 0.82; the performance of hybrids between testers is difficult to predict. GS offers the opportunity to predict the performance of new hybrids and the GCA of new inbred lines based on the molecular marker information, the total breeding cost could be reduced dramatically by phenotyping fewer multiple-location trials.

IntroductionIntegrating the heterogeneity of small-scale agriculture with the regulation, material, and non-material contributions is key to complementing the rural-support policy instruments. The objectives of the present study were to analyze the diversity of agricultural types of management in small-scale maize agroecosystems and discuss their implications for nature's contributions in the region of Valles Altos, México.MethodsThe methodology was conducted by constructing an agricultural management typology with multivariate statistical analysis for 112 small plots interviews. The operationalization of regulation, material, and non-material nature's contributions was based on the definition and counting of cultural elements from agronomic management for each class of contribution.ResultsThe results indicate three different types of agricultural management defined mainly by the type of seed, the destination of harvest, and the type of tillage. This management diversity is guided by farmers' motivation to achieve food self-sufficiency or generate income from grain sales. Each management type has a unique provision of regulation, material, and no material contributions defined by the use of the native seed, use of stover, and management diversification.DiscussionThe integration of farm typology methods and nature's contributions framework reveals that it is critical to establish new incentives that include the biological and cultural diversity of agroecosystems and the individual motivations of farmers. This may help conserve the natural and cultural values of agriculture and design appropriate incentives for small-scale agriculture.

BackgroundIncreasing numbers of opioid-overdose deaths have been witnessed among Hispanics and other underserved populations in Massachusetts. Puerto Rican adults (PRs) have a disproportionately higher prevalence of chronic diseases than non-Hispanic White adults-conditions linked to increased prescription opioid use and misuse. Stress indicators, including low acculturation, low social support, and perceived discrimination, have been recognized as correlates of chronic diseases. However, little research has been undertaken on how these socio-cultural factors relate to persistent prescription opioid use among PRs. This study evaluated the prevalence of prescription opioid use and socio-cultural factors associated with persistent prescription opioid use among PRs.MethodsData from the prospective population-based Boston Puerto Rican Health Study, at baseline, ~2-year, and ~ 6-year follow-up, were used to estimate prescription opioid use prevalence and its associations with acculturation, social support, and perceived discrimination. Analyses were conducted using multivariable binary logistic regression modeling.ResultsThe study sample was comprised of 798 PRs (age 56.5 ± 7.5y) with data at all three-time points. A high prevalence of prescription opioid use was observed and was associated with lower household income. PRs with experiences of perceived discrimination had higher odds of persistent prescription opioid use (y/n; OR = 2.85, 95% CI: 1.46-5.58). No significant associations were found between acculturation, social support, and persistent prescription opioid use.ConclusionOur study reported a high prevalence of prescription opioid use in PRs, with persistent prescription opioid use significantly associated with perceived discrimination. Future programs to limit discrimination practices may reduce persistent prescription opioid use and opioid-related complications among PRs.

Zinc deficiency poses a significant health challenge worldwide, particularly in regions where access to and the affordability of dietary diversity are limited. This research article presents a time course analysis of kernel development on the zinc content in maize kernels with different genetic backgrounds, including normal maize, quality protein maize, and high-zinc maize, grown at two locations. Zn concentrations during stage I were high, decreasing between stages II and IV and increasing during stages V to VII. High-zinc kernel genotypes, including those ones with high-quality protein genetic backgrounds, have higher contents of zinc and iron during the milky stage (fresh/green maize). The zinc and iron content in fresh maize differed depending on the genotype. By consuming fresh maize biofortified with zinc, up to 89% and 100% of EAR needs can be fulfilled for pregnant women and children. The results demonstrate that fresh high-zinc maize accumulates a substantial amount of this micronutrient, highlighting its potential as a valuable source for addressing zinc deficiency.

Traditional approaches to understanding metabolomics in mental illness have focused on investigating a single disorder or comparisons between diagnoses, but a growing body of evidence suggests substantial mechanistic overlap in mental disorders that could be reflected by the metabolome. In this study, we investigated associations between global plasma metabolites and abnormal scores on the depression, anxiety, and phobic anxiety subscales of the Brief Symptom Inventory (BSI) among 405 older males who participated in the Normative Aging Study (NAS). Our analysis revealed overlapping and distinct metabolites associated with each mental health dimension subscale and four metabolites belonging to xenobiotic, carbohydrate, and amino acid classes that were consistently associated across all three symptom dimension subscales. Furthermore, three of these four metabolites demonstrated a higher degree of alteration in men who reported poor scores in all three dimensions compared to men with poor scores in only one, suggesting the potential for shared underlying biology but a differing degree of perturbation when depression and anxiety symptoms co-occur. Our findings implicate pathways of interest relevant to the overlap of mental health conditions in aging veterans and could represent clinically translatable targets underlying poor mental health in this high-risk population.

Abstract We present an assessment of the extent, diversity, and nutritional contribution of the milpa through a quantitative analysis of data from a survey conducted in 989 small scale farm households in the Western Highlands of Guatemala (WHG). The milpa is a traditional agricultural system in which maize is intercropped with other species, such as common beans, faba beans, squashes or potatoes. Our study shows that more than two-thirds of the 1,205 plots recorded were under the milpa system, with a great diversity of crop combinations. As shown with the 357 plots for which specific yields were available, milpa systems present higher total productivity than monocropped maize, expressed as total energy yield of the harvested crops in the respective system, and were also better at providing the recommended daily allowances of fourteen essential nutrients, based on a Potential Nutrient Adequacy (PNA) indicator. Maize-bean-potato, maize-potato, and maize-bean-faba intercrops had the highest PNAs, and monocropped maize, the lowest. These results support the implementation of milpa systems tailored to different agro-ecologies in order to improve nutrition in the WHG and a variety of similar regions.

High kernel-zinc maize varieties are available to consumers in several countries in Latin America to contribute to increase the zinc intake of their populations. Minerals, phytic acid and amino acids retention were measured after processing six maize varieties including three high kernel-zinc, one quality protein maize and two conventional maize. Grain for each variety was processed into tortillas, arepas and mazamorra, common maize dishes in the region. To evaluate the effect of processing kernel-zinc maize varieties on zinc retention, varieties were grouped in zinc biofortified maize (ZBM) and non-ZBM. Iron, zinc, phytic acid, tryptophan and lysine concentrations in non-processed maize were 17.1–19.1 ​μg/g DW, 23.9–33.0 ​μg/g DW, 9.9–10.0 ​mg/g DW, 0.06–0.08% and 0.27–0.37%, respectively. In tortillas, the iron, zinc, phytic acid and lysine content did not change (p ​

Zinc (Zn) deficiency is a major risk factor for human health, affecting about 30% of the world’s population. To study the potential of genomic selection (GS) for maize with increased Zn concentration, an association panel and two doubled haploid (DH) populations were evaluated in three environments. Three genomic prediction models, M (M1: Environment + Line, M2: Environment + Line + Genomic, and M3: Environment + Line + Genomic + Genomic x Environment) incorporating main effects (lines and genomic) and the interaction between genomic and environment (G x E) were assessed to estimate the prediction ability (rMP) for each model. Two distinct cross-validation (CV) schemes simulating two genomic prediction breeding scenarios were used. CV1 predicts the performance of newly developed lines, whereas CV2 predicts the performance of lines tested in sparse multi-location trials. Predictions for Zn in CV1 ranged from -0.01 to 0.56 for DH1, 0.04 to 0.50 for DH2 and -0.001 to 0.47 for the association panel. For CV2, rMP values ranged from 0.67 to 0.71 for DH1, 0.40 to 0.56 for DH2 and 0.64 to 0.72 for the association panel. The genomic prediction model which included G x E had the highest average rMP for both CV1 (0.39 and 0.44) and CV2 (0.71 and 0.51) for the association panel and DH2 population, respectively. These results suggest that GS has potential to accelerate breeding for enhanced kernel Zn concentration by facilitating selection of superior genotypes.

Current approaches to supporting students in the transition to elementary school fail to meet the needs of Latinx immigrant children and their families in the United States. Typical approaches place the responsibility on families to help their children adapt to the expectations of their teacher, classroom, and school without recognizing the specific barriers to participation faced by Latinx immigrant parents. In this article, we describe these barriers and consider the ways community-based practice can support and prioritize co-constructed partnerships among teachers, schools, parents, and communities.

Smallholder farmers who grow maize landraces face important challenges to preserve their seed biodiversity from one season to another. This study was carried out in the central highlands of Mexico to compare the effectiveness of two seed storage practices—specifically, polypropylene woven bags (farmers’ conventional practice) vs. hermetic containers—for minimizing seed losses and maintaining germination. Four Mexican landraces were stored for three and six months. Data on moisture content and kernel damage were collected at the beginning and the end of the storage period. Pest-free samples collected were also analyzed for seed germination. Moisture content was below 13% overall and was not significantly affected by storage technology or storage time. Samples from the polypropylene woven bags suffered significant damage from Sitophilus zeamais and Prostephanus truncatus, with the percentages of insect damage and weight loss reaching 61.4% and 23.4%, respectively. Losses were minimal in seed stored in hermetic containers, with a maximum insect damage of 4.1% and weight loss of 2.2%. Overall, the germination rate of samples stored in these airtight containers was greater than 90%. This study provides additional evidence on the effectiveness of hermetic containers at maintaining Mexican landraces’ seed quantity and quality during storage in smallholder conditions in central Mexico.

Background: The impact of Levodopa on the gut microbiota of Parkinson's disease (PD) patients has not been sufficiently addressed.Methods: We conducted a longitudinal study to examine the impact of Levodopa initiation on the gut microbiota composition of 19 PD patients who had not previously been exposed to Levodopa. Patients provided two stool samples prior to and two samples 90 days after starting Levodopa. Motor impairment (MDS-UPDRS Part III), diet, and other patient characteristics were assessed. 16S rRNA gene amplicon sequencing was used to characterize the microbiota. We examined, cross-sectionally and longitudinally, the associations between Levodopa use and alpha and beta diversity and performed feature-wise, multivariate modeling to identify taxa associated longitudinally with Levodopa use and with improvement in motor function after Levodopa administration.Results: We did not observe significant differences in alpha or beta diversity before vs. after initiation of Levodopa. In longitudinal feature-wise analyses, at the genus level, no taxa were significantly associated with Levodopa use after false discovery rate (FDR) correction (q < 0.05). We observed a marginally lower relative abundance of bacteria belonging to Clostridium group IV in PD patients who experienced a medium or large improvement in motor impairment in response to Levodopa compared to those with a small response [β = −0.64 (SE: 0.18), p-trend: 0.00015 p-FDR: 0.019].Conclusions: In this study, Levodopa was not associated with changes in microbiota composition in this longitudinal analysis. The association between abundance of Clostridium group IV and short-term motor symptom response to Levodopa is preliminary and should be investigated in larger, longer-term studies, that include a control group.

Maize is one of the three worldwide cereal crops with the most outstanding production; however, its postharvest losses range from 2 to 40% due to inadequate harvesting, drying, and storage technologies. This study focuses on the Instant Controlled Pressure Drop technology (DIC) effect on maize kernels’ drying and rehydration kinetics. In total, 19 different DIC treatments were carried out on maize kernels (~25% d.b.). The DIC parameters studied were steam pressure (0.1 to 0.4 MPa) and treatment time (10 to 90 s). After DIC treatment, drying kinetics were carried out by Convective Air Drying (CAD) at 50 °C and 0.4 ms−1 airflow. Rehydration kinetics and Water Holding Capacity (WHC) were evaluated at 20 °C. In comparison to CAD samples, DIC (0.4 MPa and 90 s) reduced the drying time from 180 min to ~108 min. Additionally, regarding the rehydration and WHC results, DIC achieved the same moisture content in only 3.5 min that controls achieved after 1 h of rehydration (0.40 g H2O/g dry matter). Moreover, DIC (0.4 MPa and nine cycles of 10 s) increased the WHC 2.3 times compared to the control. In this way, DIC could be a postharvest technology to improve maize kernels’ drying operations and functional properties.

BackgroundA number of studies have reported the association between the use of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin-II receptor blocker (ARB) medications and the occurrence or severity of coronavirus disease 2019 (COVID-19). Published results are inconclusive, possibly due to differences in participant comorbidities and sociodemographic backgrounds. Since ACEI and ARB are frequently used anti-hypertension medications, we aim to determine whether the use of ACEI and ARB is associated with the occurrence and severity of COVID-19 in a large study of US Veterans with hypertension.MethodsData were collected from the Department of Veterans Affairs (VA) National Corporate Data Warehouse (VA-COVID-19 Shared Data Resource) between February 28, 2020 and August 18, 2020. Using data from 228,722 Veterans with a history of hypertension who received COVID-19 testing at the VA, we investigated whether the use of ACEI or ARB over the two years prior to the index date was associated with increased odds of (1) a positive COVID-19 test, and (2) a severe outcome (hospitalization, mortality, and use of intensive care unit (ICU) and/or mechanical ventilation) among COVID-19-positive patients. We used logistic regression with and without propensity score weighting (PSW) to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for the association between ACEI/ARB use and a positive COVID-19 test result. The association between medication use and COVID-19 outcome severity was examined using multinomial logistic regression comparing participants who were not hospitalized to participants who were hospitalized, were admitted to the ICU, used a mechanical ventilator, or died. All models were adjusted for relevant covariates, including demographics (age, sex, race, ethnicity), selected comorbidities, and the Charlson Comorbidity Index (CCI).ResultsThe use of ACEI significantly decreased the odds of a positive COVID-19 test among Veterans with hypertension (OR = 0.917, (0.887, 0.948) and OR = 0.926, (0.894, 0.958) with PSW). The use of ACEI, but not of ARB, was also associated with significantly increased odds of using mechanical ventilators (OR = 1.265, (1.010, 1.584) and OR = 1.210, (1.053, 1.39) with PSW) among all COVID-19 inpatients compared to outpatients.ConclusionsIn this study of Veterans with hypertension, ACEI was significantly associated with decreased odds of testing positive for COVID-19. With the exception of the association of ACEI with a small non-clinically-important increase in the odds of using mechanical ventilators, neither ACEI nor ARB was found to be associated with clinical severity or mortality among COVID-19-positive Veterans. The results of this study need further corroboration and validation in other cohort samples outside the VA.

Agri-food systems are besieged by malnutrition, yield gaps, and climate vulnerability, but integrated, research-based responses in public policy, agricultural, value chains, and finance are constrained by short-termism and zero sum thinking. As they respond to current and emerging agri-food system challenges, decision makers need new tools that steer toward multi-sector, evidence-based collaboration. To support national agri-food system policy processes, the Integrated Agri-food System Initiative (IASI) methodology was developed and validated through case studies in Mexico and Colombia. This holistic, multi-sector methodology builds on diverse existing data resources and leverages situation analysis, modeled predictions, and scenarios to synchronize public and private action at the national level toward sustainable, equitable, and inclusive agri-food systems. Culminating in collectively agreed strategies and multi-partner tactical plans, the IASI methodology enabled a multi-level systems approach by mobilizing design thinking to foster mindset shifts and stakeholder consensus on sustainable and scalable innovations that respond to real-time dynamics in complex agri-food systems. To build capacity for these types of integrated, context-specific approaches, greater investment is needed in supportive international institutions that function as trusted in-region 'innovation brokers.' This paper calls for a structured global network to advance adaptation and evolution of essential tools like the IASI methodology in support of the One CGIAR mandate and in service of positive agri-food systems transformation.

Enriching of kernel zinc (Zn) concentration in maize is one of the most effective ways to solve the problem of Zn deficiency in low and middle income countries where maize is the major staple food, and 17% of the global population is affected with Zn deficiency. Genomic selection (GS) has shown to be an effective approach to accelerate genetic gains in plant breeding. In the present study, an association-mapping panel and two maize double-haploid (DH) populations, both genotyped with genotyping-by-sequencing (GBS) and repeat amplification sequencing (rAmpSeq) markers, were used to estimate the genomic prediction accuracy of kernel Zn concentration in maize. Results showed that the prediction accuracy of two DH populations was higher than that of the association mapping population using the same set of markers. The prediction accuracy estimated with the GBS markers was significantly higher than that estimated with the rAmpSeq markers in the same population. The maximum prediction accuracy with minimum standard error was observed when half of the genotypes were included in the training set and 3,000 and 500 markers were used for prediction in the association mapping panel and the DH populations, respectively. Appropriate levels of minor allele frequency and missing rate should be considered and selected to achieve good prediction accuracy and reduce the computation burden by balancing the number of markers and marker quality. Training set development with broad phenotypic variation is possible to improve prediction accuracy. The transferability of the GS models across populations was assessed, the prediction accuracies in a few pairwise populations were above or close to 0.20, which indicates the prediction accuracies across years and populations have to be assessed in a larger breeding dataset with closer relationship between the training and prediction sets in further studies. GS outperformed MAS (marker-assisted-selection) on predicting the kernel Zn concentration in maize, the decision of a breeding strategy to implement GS individually or to implement MAS and GS stepwise for improving kernel Zn concentration in maize requires further research. Results of this study provide valuable information for understanding how to implement GS for improving kernel Zn concentration in maize.

Vitamin A deficiency (VAD) is a public health issue worldwide. Provitamin A (PVA) biofortified maize serves as an alternative to help combat VAD. Breeding efforts to develop maize varieties with high PVA carotenoid content combine molecular and phenotypic selection strategies. The phenotypic assessment of carotenoids is currently done using liquid chromatography, a precise but time- and resource-consuming methodology. Using near-infrared spectroscopy (NIRS) could increase the breeding efficiency. This study used ultra-performance liquid chromatography (UPLC) data from 1857 tropical maize genotypes as a training set and NIRS data to do an independent test of a set of 650 genotypes to predict PVA carotenoids using Bayesian and modified partial least square (MPLS) regression models. Both regression methods produced similar prediction accuracies for the total carotenoids (r2 = 0.75), lutein (r2 = 0.55), zeaxanthin (r2= 0.61), β-carotene (r2 = 0.22) and β-cryptoxanthin (BCX) (r2 = 0.57). These results demonstrate that Bayesian and MPLS regression of BCX on NIRS data can be used to predict BCX content, the current focus on PVA enhancement, and thus offers opportunities for high-throughput phenotyping at a low cost, especially in the early stages of PVA maize breeding pipeline when many genotypes must be screened.

Maize is a major source of food security and economic development in sub-Saharan Africa (SSA), Latin America, and the Caribbean, and is among the top three cereal crops in Asia. Yet, maize is deficient in certain essential amino acids, vitamins, and minerals. Biofortified maize cultivars enriched with essential minerals and vitamins could be particularly impactful in rural areas with limited access to diversified diet, dietary supplements, and fortified foods. Significant progress has been made in developing, testing, and deploying maize cultivars biofortified with quality protein maize (QPM), provitamin A, and kernel zinc. In this review, we outline the status and prospects of developing nutritionally enriched maize by successfully harnessing conventional and molecular marker-assisted breeding, highlighting the need for intensification of efforts to create greater impacts on malnutrition in maize-consuming populations, especially in the low- and middle-income countries. Molecular marker-assisted selection methods are particularly useful for improving nutritional traits since conventional breeding methods are relatively constrained by the cost and throughput of nutritional trait phenotyping.

Objective. Antibiotic use is one of the strongest environmental predictors of an altered and less diverse gut microbiome, which has been linked to Parkinson’s disease. To our knowledge, no prior study has examined the association between long-term antibiotic use and Parkinson’s disease. Design. We conducted a prospective study of 59,637 women in the Nurses’ Health Study who reported total duration of antibiotic use at ages 20–39, 40–59, 60 +, or during the past 4 years. We used Cox Proportional Hazard regression to estimate hazard ratios and 95% confidence intervals for the association between categories of antibiotic use and risk of PD. Results. One hundred and eighty cases of PD were confirmed during the follow-up. Self-reported antibiotic use at ages 20–39, 40–59, and 60 +, as assessed in 2004, was not significantly associated with PD risk in our cohort. The hazard ratio comparing participants who used antibiotics for 2 or more months vs. 1–14 days at age 20–39 was 0.98 (95% CI: 0.54, 1.78), at age 40–59 was 1.44 (95% CI: 0.88, 2.33), and at age 60 +was 0.88 (95% CI: 0.53, 1.47). Antibiotic use during the past four years, as assessed in 2008, was also not associated with future risk of PD (HR: 1.14, 95% CI: 0.62, 2.10). Conclusion. In this cohort study, we did not observe a significant association between antibiotic use and incidence PD. A major limitation of our study is assessment of exposure, which required many participants to recall their antibiotic use decades in the past. Thus, although the results of this study do not support an effect of antibiotic use on PD risk, larger investigations relying on records of antibiotic prescriptions would provide more definitive evidence.

To explore the ways in which Latinx older siblings support younger siblings during shared reading, researchers investigated the following question with three Latinx families in the U.S.: "How are older siblings modeling and intentionally supporting focal children's cognitive self-regulation in the context of shared reading?" Analyses of video recorded interactions across six visits revealed that older siblings intentionally supported focal children's cognitive self-regulation by fostering autonomy and choice through the use of verbal and nonverbal cues to guide attention, using prosody to engage their sibling, and to initiate reading beyond resistance, and vicarious modeling of metacognitive processes by engaging in self-corrections and demonstrating positive affect during shared reading interactions. Findings highlight the importance of older siblings, particularly sisters, as key figures in the sociocultural context of development for Latinx younger siblings in the U.S.

Latin America is the center of domestication and diversity of maize, the second most cultivated crop worldwide. In this region, maize landraces are fundamental for food security, livelihoods, and culture. Nevertheless, genetic erosion (i.e., the loss of genetic diversity and variation in a crop) threatens the continued cultivation and in situ conservation of landrace diversity that is crucial to climate change adaptation and diverse uses of maize. We provide an overview of maize diversity in Latin America before discussing factors associated with persistence of large in situ maize diversity, causes for maize landrace abandonment by farmers, and strategies to enhance the cultivation of landraces. Among other factors, maize diversity is linked with: (1) small-holder farming, (2) the production of traditional food products, (3) traditional cropping systems, (4) cultivation in marginal areas, and (5) retention of control over the production system by the farmers. On the other hand, genetic erosion is associated with substitution of landraces with hybrid varieties or cash crops, and partial (off-farm labor) or complete migration to urban areas. Continued cultivation, and therefore on-farm conservation of genetic diversity held in maize landraces, can be encouraged by creating or strengthening market opportunities that make the cultivation of landraces and open pollinated varieties (OPVs) more profitable for farmers, supporting breeding programs that prioritize improvement of landraces and their special traits, and increasing the access to quality germplasm of landraces and landrace-derived OPVs.

Genetic improvement of maize with elevated levels of zinc (Zn) can reduce Zn deficiency among populations who rely on maize as a staple. Inbred lines of quality protein maize (QPM) and non-QPM with elevated Zn levels in the kernel have been identified. However, information about the optimal strategy to utilize the germplasm in breeding for high-Zn concentration is lacking. As a preliminary step, this study was conducted to ascertain the potential of QPM, non-QPM, or a combination of QPM and non-QPM hybrids for attaining desirable Zn concentration. Twenty elite inbreds, 10 QPM and 10 non-QPM, were crossed according to a modified mating design to generate hybrids, which were evaluated in four environments in Mexico during 2015 and 2016 in order to evaluate their merits as parents of hybrids. The highest mean values of Zn were observed when high-Zn QPM lines were crossed with high-Zn non-QPM lines. Hybrids with high Zn and grain yield were identified. General combining ability (GCA) effects for Zn concentration were more preponderant than specific combining ability (SCA) effects, suggesting the importance of additive gene action for the inheritance of Zn.

Aflatoxin contamination of maize grain and products causes serious health problems for consumers worldwide, and especially in low- and middle-income countries where monitoring and safety standards are inconsistently implemented. Vitamin A deficiency (VAD) also compromises the health of millions of maize consumers in several regions of the world including large parts of sub-Saharan Africa. We investigated whether provitamin A (proVA) enriched maize can simultaneously contribute to alleviate both of these health concerns. We studied aflatoxin accumulation in grain of 120 maize hybrids formed by crossing 3 Aspergillus flavus resistant and three susceptible lines with 20 orange maize lines with low to high carotenoids concentrations. The hybrids were grown in replicated, artificially-inoculated field trials at five environments. Grain of hybrids with larger concentrations of beta-carotene (BC), beta-cryptoxanthin (BCX) and total proVA had significantly less aflatoxin contamination than hybrids with lower carotenoids concentrations. Aflatoxin contamination had negative genetic correlation with BCX (-0.28, p < 0.01), BC (-0.18, p < 0.05), and proVA (-0.23, p < 0.05). The relative ease of breeding for increased proVA carotenoid concentrations as compared to breeding for aflatoxin resistance in maize suggests using the former as a component of strategies to combat aflatoxin contamination problems for maize. Our findings indicate that proVA enriched maize can be particularly beneficial where the health burdens of exposure to aflatoxin and prevalence of VAD converge with high rates of maize consumption.

Following a theoretical framework that recognizes the potential of promotive and inhibitive effects on children's development, this study explored child-, family-, classroom-, and school-level factors as predictors of Latinx (N = 4,590) students' early elementary science achievement. Research Findings: Employing a path modeling approach with ECLS-K:2011 data, we found that child factors were both positively (early reading, cognitive flexibility, working memory, and being older) and negatively (having a disability, being assessed in Spanish) associated with first-grade science achievement and gains between first and second grades. Family factors were also positively (higher parental education and family income) and negatively (children with foreign-born parents or who spoke Spanish at home) associated with initial science achievement but were unrelated to achievement gains. Frequency of teaching science, use of Spanish for instruction, and attending a school in the first grade with a larger percentage of Latinx children were associated with initial science achievement, while use of Spanish for instruction in first grade and whether the school made AYP in first grade predicted change in science through second grade. Policy or Practice: Results have implications for U.S. education policy, uncovering potential levers of change in supporting early science achievement among Latinx children.

En este trabajo se realizó un análisis de la calidad nutricional a 50 accesiones de maíz amarillo, colectadas en fincas de agricultores de las tres regiones de Cuba (occidente, centro y oriente). Para ello, se examinaron los caracteres siguientes: contenidos (%) de ceniza, aceite, azúcares totales, nitrógeno, lisina y triptófano, en el Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT) en México. Como resultado se obtuvieron valores normales de ceniza, aceite, azúcares y lisina; sin embargo, en el contenido de azúcares, se destacan tres accesiones. En cuanto al contenido de triptófano, el 76 % de las accesiones muestran valores relativamente altos, incluso comparados con algunos maíces de alta calidad proteica (QPM), lo que tributa a que el 74 % de la población total evaluada tenga un índice de calidad relativamente alto, que supera a la variedad normal usada como testigo e incluso siete accesiones superan a los reportes de la evaluación de un QPM en otra región. Este resultado es alentador, dado que permite trazar estrategias para elevar la calidad nutricional de algunas accesiones y utilizarlas en la alimentación de poblaciones meta y animales de interés. También se mostraron correlaciones interesantes en la población estudiada. Además, se demostró que existe dispersión en las accesiones cuando se realiza un análisis de componentes principales, existiendo accesiones que se separan de otras atendiendo a caracteres que influyen decisivamente en la calidad nutricional del maíz.

Los metabolitos secundarios producidos por las plantas están involucrados en una multitud de interacciones ecológicas, entre ellas las interacciones planta-planta, planta-microorganismos, planta-animales y planta-insectos. Además de protegerlas de algunos patógenos, también ayudan a las plantas a sobrevivir en condiciones medioambientales adversas. Dadas sus características medicinales e industriales, dichos metabolitos también son de gran importancia para el ser humano. Sin embargo, el estudio de estos compuestos en plantas tropicales a nivel bioquímico, molecular y genético, es aún limitado. Dentro de las estrategias de bioprospección de la diversidad de muchos países tropicales como Colombia, la exploración y explotación del metabolismo secundario de plantas constituye un reglón importante. En el presente trabajo se reporta una metodología experimental basada en el aislamiento de ADN genómico de plantas colectadas en campo, y el uso de cebadores degenerados empleados en la amplificación en cadena de la polimerasa (PCR) para identificar genes que codifican enzimas decarboxilasas dependientes de piridoxal. Estas enzimas están involucradas en la vía metabólica para la síntesis de alcaloides. Basados en la homología de secuencias reportadas en las bases de datos, se diseñaron cebadores degenerados para amplificar secuencias conservadas de estas enzimas en 18 familias de plantas diferentes. Se obtuvieron seis secuencias obtenidas de plantas del género Piper sp. Este reporte demuestra el potencial uso de ésta y otras metodologías actuales para aumentar el conocimiento, entendimiento y exploración del metabolismo secundario de las plantas de Colombia. Palabras clave: bioprospección, metabolismo secundario, cebadores degenerados, microarreglos, decarboxilasas dependientes de piridoxal.

Los alcaloides indol terpenoicos (TIA) son metabolitos secundarios de importancia medicinal por sus propiedades como agentes anticancerígenos, entre otras. Sin embargo, su explotación en la industria farmacéutica se ha visto limitada, ya que la acumulación de estos compuestos en las plantas que los producen es mínima. Dichos alcaloides son biosintetizados por la vía del shikimato y de los terpenoides, los cuales proveen los precursores: secologanina y triptamina, respectivamente. La secologanina es sintetizada vía terpenoides, y estudios preliminares sugieren que es sintetizada vía del 2-C-metil-D-eritrol-4-fosfato (MEP) y no vía acetato/ácido mevalónico. Se cree que la secologanina es una de las moléculas limitantes en la biosíntesis de TIA. En el presente estudio se cuantif ican y evalúan por HPLC los niveles de este compuesto y sus predecesores iridoides, ácido logánico y secologanina, en diferentes partes de la planta medi­cinal Catharanthus roseus. La distribución de estos iridoides varía según el tejido analizado, encontrándose mayor acumulación de secologanina en el segundo par de hojas de la planta. Los niveles de transcriptos de las enzimas involucradas en los pasos tempranos de la vía de los iridoides fueron monitoreados también en diferentes tejidos usando la técnica transferencia de ARN, Northern blots. Adicionalmente, las plantas se elicitaron con jasmonato de metilo (MeJA), con el fin de estudiar el efecto de esta molécula en la trans­cripción de genes que codifican enzimas involucradas en los pasos tempranos de la vía de los iridoides. Los resultados obtenidos en este estudio sugieren que la vía del MEP puede estar más activa que la vía del acetato/ácido mevalónico en tejidos aéreos jóvenes de la planta. Adicionalmente, es evidente que el MeJA afecta la biosíntesis de TIA estimulando la transcripción de diferentes genes. Palabras clave: metabolismo secundario, alcaloides indol terpenoicos, jasmonato de metilo, vía del mevalonato, secologanina.

Students' academic achievement is the result of the interplay between person-level and contextual factors (R. R: Greene, 2014; D. E. Hunt, 1975). Students perform better when classroom characteristics support their characteristics. The authors examine whether student perceptions of two classroom characteristics (care and control) fit with two Latino student characteristics (English language learner status and grit) in relation to their academic achievement. Using a sample of fourth- and fifth-grade Latino students from the Measures of Effective Teaching dataset (n =3,272), the authors conducted a series of nested regression models with two- and three-way interactions between student characteristics and student perceptions of classroom characteristics. Findings revealed that grit is most strongly associated with Latino English language learners' English/language arts achievement when students perceived that teachers used high levels of care and control. We conclude with implications for practitioners.