Biomarkers of systemic inflammation and growth in early infancy are associated with stunting in young Tanzanian children

Stunting can afflict up to one-third of children in resource-constrained countries. We hypothesized that low-grade systemic inflammation (defined as elevations in serum C-reactive protein or alpha-1-acid glycoprotein) in infancy suppresses the growth hormone–insulin-like growth factor (IGF) axis and is associated with subsequent stunting. Blood samples of 590 children from periurban Dar es Salaam, Tanzania, were obtained at 6 weeks and 6 months of age as part of a randomized controlled trial. Primary outcomes were stunting, underweight, and wasting (defined as length-for-age, weight-for-age and weight-for-length z-scores < −2) between randomization and endline (18 months after randomization). Cox proportional hazards models were constructed to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of time to first stunting, underweight, and wasting as outcomes, with measures of systemic inflammation, insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) as exposures, adjusting for numerous demographic and clinical variables. The incidences of subsequent stunting, underweight, and wasting were 26%, 20%, and 18%, respectively. In multivariate analyses, systemic inflammation at 6 weeks of age was significantly associated with stunting (HR: 2.14, 95% CI: 1.23, 3.72; p = 0.002). Children with higher levels of IGF-1 at 6 weeks were less likely to become stunted (HR: 0.58, 95% CI: 0.37, 0.93; p for trend = 0.019); a similar trend was noted in children with higher levels of IGF-1 at 6 months of age (HR: 0.50, 95% CI: 0.22, 1.12; p for trend = 0.07). Systemic inflammation occurs as early as 6 weeks of age and is associated with the risk of future stunting among Tanzanian children.This research was funded by the National Institutes of Health (R01 HD048969, 2P30 DK040561, K24 DK104676-Dr. Duggan) and the Bill and Melinda Gates Foundation (OPP1066203-Dr. Duggan). (R01 HD048969 - National Institutes of Health; 2P30 DK040561 - National Institutes of Health; K24 DK104676 - National Institutes of Health; OPP1066203 - Bill and Melinda Gates Foundation)Accepted manuscrip

The impact of integrated infant and young child feeding and micronutrient powder intervention on feeding practices and anemia in children aged 6-23 months in Madagascar

This study assesses the impact of an integrated infant and young child feeding (IYCF) and micronutrient powder (MNP) intervention on children's risk of anemia and IYCF practices in Madagascar. Quantitative baseline and endline surveys were conducted in representative households with children 6-23 months from two districts, where an 18-month IYCF-MNP intervention was implemented. Relative risks comparing children's risk of anemia and maternal IYCF knowledge and practices at baseline versus endline, and also at endline among MNP-users versus non-users were estimated using log-binomial regression models. 372 and 475 children aged 6-23 months were assessed at baseline and endline respectively. Prevalence of anemia fell from 75.3% to 64.9% from baseline to endline (p = 0.002); the reduction in the risk of anemia remained significant in models adjusting for sociodemographic characteristics (ARR (95% CI): 0.86 (0.78, 0.95), p = 0.003). In endline assessments, 229 out of 474 (48.3%) of children had consumed MNPs. MNP-users had a lower risk of anemia (ARR (95% CI): 0.86 (0.74, 0.99), p = 0.04) than non-users, after controlling for child's dietary diversity and morbidity, maternal counseling by community-health-workers, and sociodemographic characteristics. Mothers interviewed at endline also had greater nutrition knowledge and were more likely to feed their children ≥4 food groups (ARR (95% CI): 2.92 (2.24, 3.80), p < 0.001), and the minimum acceptable diet (ARR (95% CI): 2.88 (2.17, 3.82), p < 0.001) than mothers interviewed at baseline. Integration of MNP into IYCF interventions is a viable strategy for improving children's consumption of micronutrients and reducing risk of anemia. The addition of MNP does not negatively impact, and may improve, IYCF practices.We are grateful to all of the mothers and children and participating communities, as well as data enumerators, and the USAID-supported SALOHI project team for the technical and financial support during the baseline and endline surveys. We also thank Jacky Raharinjatovo the PSI-Madagascar statistician for support in analyses as well as Roland Kupka, France Begin and Jennifer Marcy for their comments and feedback on this manuscript. The views expressed in this manuscript are those of the authors and do not necessarily reflect the official positions or policies of their affiliated institutions. Both the baseline and the endline surveys were funded by USAID/SALOHI. (USAID; USAID/SALOHI)Published versio

Multivitamin Supplementation Improves Haematologic Status in Children Born to HIV-positive women in Tanzania.

Anaemia is prevalent among children born to HIV-positive women, and it is associated with adverse effects on cognitive and motor development, growth, and increased risks of morbidity and mortality. To examine the effect of daily multivitamin supplementation on haematologic status and mother-to-child transmission (MTCT) of HIV through breastfeeding. A total of 2387 infants born to HIV-positive women from Dar es Salaam, Tanzania were enrolled in a randomized, double-blind, placebo-controlled trial, and provided a daily oral supplement of multivitamins (vitamin B complex, C and E) or placebo at age 6 weeks for 24 months. Among them, 2008 infants provided blood samples and had haemoglobin concentrations measured at baseline and during a follow-up period. Anaemia was defined as haemoglobin concentrations <11 g/dL and severe anaemia <8.5 g/dL. Haemoglobin concentrations among children in the treatment group were significantly higher than those in the placebo group at 12 (9.77 vs. 9.64 g/dL, p=0.03), 18 (9.76 vs. 9.57 g/dL, p=0.004), and 24 months (9.93 vs. 9.75 g/dL, p=0.02) of follow-up. Compared to those in the placebo group, children in the treatment group had a 12% lower risk of anaemia (hazard ratio (HR): 0.88; 95% CI: 0.79-0.99; p=0.03). The treatment was associated with a 28% reduced risk of severe anaemia among children born to women without anaemia (HR: 0.72; 95% CI: 0.56-0.92; p=0.008), but not among those born to women with anaemia (HR: 1.10; 95% CI: 0.79-1.54; p=0.57; p for interaction=0.007). One thousand seven hundred fifty three infants who tested HIV-negative at baseline and had HIV testing during follow-up were included in the analysis for MTCT of HIV. No association was found between multivitamin supplements and MTCT of HIV. Multivitamin supplements improve haematologic status among children born to HIV-positive women. Further trials focusing on anaemia among HIV-exposed children are warranted in the context of antiretroviral therapy

Knowledge and debate in the American Journal of Clinical Nutrition: new sections, new science, and looking forward and outward

New scientific areas of inquiry and tools require new approaches from the scientific literature, and nutrition is no exception. We expect that these new features will generate tremendous interest, as measured by website traffic and citations, and that articles in these new series, as well as our standard sections, will be enjoyed by the broad AJCN readership

How Many Squirrels Are in the Shrubs? A Lesson Plan for Comparing Methods for Population Estimation

Estimating the population sizes of animals is a key skill for any student interested in ecology, conservation, or management. However, counting animals in natural habitats is difficult, and the many techniques that exist each rely on assumptions that can bias results. Most wildlife courses teach one or two of these methods, but rarely are students given an opportunity to compare approaches and explore how underlying assumptions affect the accuracy of estimates. Here, we describe a hands-on activity in which students estimate the size of a single population of animals using multiple methods: strip censuses, scat counts, and camera traps. They then compare the estimates and evaluate how the assumptions of each model (e.g., random use of habitats and animal behavior) bias the results. Finally, students submit their data to a national database that aggregates observations across multiple institutions as part of Squirrel-Net (http://squirrel-net.org). They can then analyze the national dataset, permitting exploration of these questions across a broader variety of habitats and species than would be possible at any single institution. Extensions of this activity guide students to enumerate the advantages and disadvantages of each method in different contexts and to select the most appropriate method for a given scenario. This activity and the database focus on estimating population sizes of squirrels, which are diurnal, charismatic, easily identified, and present in a wide range of habitats (including many campuses), but the same methods could be broadly used for other terrestrial species, including birds, amphibians, reptiles, or invertebrates

Squirrels in Space: Using Radio Telemetry to Explore the Space Use and Movement of Sciurid Rodents

Biotelemetry is used by researchers to track the interactions of animals with each other and the environment. While advancing technology has led to the development of numerous biotelemetry tools, radio telemetry remains the most common method for tracking small animals. Moreover, telemetry tracking of animal movement is an important skill for entry-level positions in wildlife biology. Thus, hands-on experience using radio telemetry provides students with an advantage as they pursue careers in wildlife biology, as well as an opportunity to build science process skills. We present a lesson in which students use radio telemetry to track animals; collect, analyze and interpret spatial data; and consider its applications to local wildlife management and conservation. Students submit their data to a national database collecting observations from multiple institutions as part of Squirrel-Net (http://squirrel-net.org). The aggregated data allows students to generate and test hypotheses across a broader variety of species and habitats than would be possible at any single institution. The lesson is designed for adaptation to diverse educational contexts, from a single two-hour laboratory period (basic skills acquisition) to a semester-long student-driven research project (open inquiry Course-based Undergraduate Research Experience, or CURE). Although this activity and the national database focus on spatial data for squirrels, which are diurnal, charismatic, easily identified, and present on most college campuses, the same methods and materials can be modified for any animal capable of carrying a radio transmitter and being safely tracked by students

Squirreling from Afar: Adapting Squirrel-Net Modules for Remote Teaching and Learning

The shift from face-to-face instruction to remote teaching and learning has proven to be a challenging endeavor for many reasons, including lack of time, resources, and inspiration. Lab courses, the “hands-on” portion of many curricula, may be especially difficult to adapt to online learning given the common use of specialized equipment, materials, and techniques that require close supervision. Without the time and resources to creatively modify existing activities or create new ones, remote lab courses run the risk of becoming less effective, equitable, and/or engaging. Squirrel-Net has created four field-based activities for biology labs that are easy to implement, highly flexible for different course aims, and readily adaptable to a remote learning environment. In this essay, we briefly summarize the modules and propose several ways that each can be adjusted to accommodate online teaching and learning. By providing authentic learning opportunities through distance delivery we hope to promote widespread student engagement and creative solutions for instructors

Sorry to Eat and Run: A Lesson Plan for Testing Trade-off in Squirrel Behavior Using Giving Up Densities (GUDs)

All animals need to find and compete for food, shelter, and mates in order to survive and reproduce. They also need to avoid being eaten by predators. Optimal foraging theory provides a framework to examine the trade-offs individuals make while foraging for food, taking into account an animal’s body condition, predation pressure, quality of food resources, and food patch availability in the habitat. Here we describe an activity that uses Giving Up Densities (GUDs), which could be used as part of a course-based undergraduate research experience (CURE) or as a stand-alone activity. GUDs provide an experimental approach to quantify the costs and benefits of foraging in a particular patch and is simple to measure in that it is literally the density of food remaining in a patch. However, its interpretation allows students to compare foraging decisions under different environmental conditions, between species, or with different food sources. This activity was designed to study the foraging behavior of squirrels, which are active during the day, forage on seeds, and are found on and around many college campuses, but it can be adapted to nocturnal animals, birds, or other vertebrates. This module is hands-on. Students weigh seeds, sift sand, walk out into the field with bags of sand and trays, and analyze data. The module can be designed at various levels of inquiry to suit the needs of a particular class. Further, students can work individually, in pairs, or in teams. Finally, students and instructors are encouraged to upload their data to a national dataset, which is available to instructors for use in the classroom to broaden the possible hypotheses and analyses students can explore

An Introduction to the Squirrel-Net Teaching Modules

Although course-based undergraduate research experiences (CUREs) are gaining popularity in biology, most are designed for benchwork-based laboratory courses while few focus on field-based skills. Many barriers to implementing field CUREs exist, including the difficulty in designing authentic research that can be accomplished in a limited lab timeframe, permitting and liability issues, and problems gathering sufficient data to meaningfully analyze. Squirrel-Net (http://squirrel-net.org) is a consortium of mammalogists from eight different institutions who have worked to overcome these limitations through four field-based CUREs focused on sciurid rodents (e.g., squirrels, chipmunks, marmots, prairie dogs). Each module is linked to a national dataset, allowing for broader and more complex hypotheses and analyses than would be possible from a single institution. Modules have been field tested at different institutions and are easily implemented and highly flexible for different courses, levels of inquiry, habitats, and focal species. Beyond the basic lesson plan, each module also provides suggestions for adaptation at different levels of inquiry and scaffolding across a course or an entire curriculum. Moreover, our website provides templates to help lower barriers to CURE implementation (e.g., selecting a field site and writing institutional animal care protocols). Here, we introduce Squirrel-Net and give an overview of the four CURE modules. Additionally, we demonstrate how the modules can be used singly or together to provide authentic research experiences to a diversity of undergraduates

Squirreling Around for Science: Observing Sciurid Rodents to Investigate Animal Behavior

Hands-on research experiences are important opportunities for students to learn about the nature of inquiry and gain confidence in solving problems. Here, we present an inquiry-based lesson plan that investigates the foraging behavior of sciurid rodents (squirrels) in local habitats. Squirrels are an ideal study system for student research projects because many species are diurnal, easy to watch, and inhabit a range of habitats including college campuses. In this activity, instructors identify appropriate field sites and focal species, while students generate questions and brainstorm predictions in small groups regarding factors that might influence behavioral trade-offs in sciurids. Students conduct observational surveys of local squirrels in pairs using a standardized protocol and upload their data to a national database as part of the multi-institutional Squirrel-Net (http://squirrel-net.org). Instructors access the nationwide dataset through the Squirrel-Net website and provide students with data for independent analysis. Students across the country observe and record a range of squirrel species, including behaviors and habitat characteristics. The national dataset can be used to answer student questions about why squirrels behave in the way they do and for students to learn about authentic analyses regarding behavior trade-offs. Additionally, the lesson is designed to be modified across a range of inquiry levels, from a single two-hour laboratory activity to a unit- or semester-long student-driven course-based research experience. Our activity highlights the value of using observational data to conduct research, makes use of the Squirrel-Net infrastructure for collaboration, and provides students equitable access to field-based projects with small mammals