9 research outputs found
Mechanisms of adaptation to climate variability in West African pearl millet landraces – a preliminary
Landraces are generally expected to possess specific
mechanisms of adaptation to their growing environments.
In West and Central Africa (WCA), growing conditions
of pearl millet (Pennisetum glaucum) are characterized,
among other hazards, by highly variable beginnings and
endings of the rainy season, and unpredictable drought
stress at any time during the growing season. Adaptation
to such unpredictable variable environment can be due to
individual and/or populational buffering (Allard and
Bradshaw 1964), two mechanisms initially defined by
Lerner (1954) as developmental and genetic
homeostasis. Individual buffering may be favored by
phenotypic plasticity. Photoperiod-sensitive flowering is
an example of phenotypic plasticity that can enhance
adaptation to variable planting dates followed due to a
scattered beginning of the rainy season in a region, as
typical for WCA. It enhances simultaneous flowering of
the cultivar in the target region, independent of the
individual date of planting in different fields. This has
particular advantages in terms of reducing bird damage
and insect pressure; prolonging vegetative development
in case of early planting but accelerating development in
case of late planting; therefore fitting plant development
to available rainfall patterns and resulting potentially in
increased yielding stability. Populational buffering can
be promoted by genetic heterogeneity in plant stand as
different genotypes present in the population are
specifically adapted to different environmental
conditions (Bradshaw 1965). An example is intra-varietal
variation for flowering time, which would assure that in
case of a dry spell, not all plants in the field will be
affected by drought in their most sensitive flowering
stage
Characterization of West and Central African accessions from a pearl millet reference collection for agro-morphological traits and Striga resistance
To promote the utilization of West and Central African (WCA) genetic resources of pearl millet [Pennisetum glaucum (L.) R. Br.], this study aimed at agro-morphological characterization of selected accessions from the pearl millet reference collection, established by the Generation Challenge Program and the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). A total of 81 accessions were included, comprising 78 landraces originating from 13, predominantly WCA countries and three improved cultivars. All 81 accessions were evaluated together with 18 checks for resistance to the parasitic weed Striga hermonthica (Del.) Benth. in an artificially infested field at one location in Niger. Determined by available seed quantity, 74 accessions were characterized together with seven checks in the rainy season 2009 in field trials under low-input and fertilized conditions in Nigeria, Niger and Mali, respectively. Wide ranges were observed for various traits. Several accessions were identified as sources for specific traits of interest, i.e. long panicles, high-grain density, earliness, Striga resistance and stable yielding across environments. The observed yield inferiority of all Genebank accessions compared with checks may indicate lost adaptation or inbreeding depression due to an insufficient effective population size during multiplication. A principal component analysis revealed an immense diversity but also strong admixture among the tested accessions, i.e. there were no clearly distinct groups. The seed of all genotypes is available from ICRISAT. The online availability of the characterization data is expected to facilitate efficient use of these pearl millet accessions by breeding programmes in WCA and worldwide
Identification of High-Yielding Iron-Biofortified Open-Pollinated Varieties of Pearl Millet in West Africa
Pearl millet is a predominant food and fodder crop in West Africa. This study was
carried out to test the newly developed open-pollinated varieties (OPVs) for field
performance and stability for grain yield, grain iron (Fe), and grain zinc (Zn) contents
across 10 locations in West Africa (i.e., Niger, Nigeria, Mali, Burkina Faso, Senegal, and
Ghana). The test material consisted of 30 OPVs, of which 8 are Fe/Zn biofortified. The
experiment was conducted in a randomized complete block design in three replications.
ANOVA revealed highly significant variability for grain yield and micronutrient traits. The
presence of genotype x environment (G x E) indicated that the expressions of traits are
significantly influenced by both genetic and G x E factors, for grain Fe and Zn contents.
Days to 50% flowering and plant height showed less G x E, suggesting these traits are
largely under genetic control. The genotypes CHAKTI (46 days), ICTP 8203 (46 days),
ICMV 177002 (50 days), ICMV 177003 (48 days), and Moro (53 days) had exhibited
early flowering across locations leading to early physiological maturity. CHAKTI (1.42 t/ha
yield; 62.24 mg/kg of grain Fe, 47.29 mg/kg of grain Zn) and ICMP 177002 (1.19 t/ha
yield, 62.62 mg/kg of grain Fe, 46.62 mg/kg of grain Zn) have performed well for grain
yield and also for micronutrients, across locations, compared with the check. Additive
Main Effect and Multiplicative Interaction (AMMI) ANOVA revealed the highly significant
genotypic differences, the mean sum of squares of environment, and its interaction with
the genotypes. Based on the AMMI stability value (ASV), the most stable genotype is
SOSAT-C88 (ASV = 0.04) for grain yield and resistance to downy mildew; mean grain
yield and stability rankings (YSI) revealed that the genotypes CHAKTI, SOSAT-C88, and
ICMV IS 99001 were high yielding and expressed stability across regions. The strong
correlation (r = 0.98**) of grain Fe and Zn contents that merits Fe-based selection
is highly rewarding. CHAKTI outperformed over other genotypes for grain yield (71% higher), especially with early maturing varieties in West Africa, such as GB 8735, LCIC
9702, and Jirani, and for grain Fe (16.11% higher) and Zn (7% higher) contents across
locations, and made a candidate of high-iron variety to be promoted for combating the
micronutrient malnutrition in West and Central Africa (WCA)
A national e-health program for the prevention and management of overweight and obesity in childhood and adolescence in Greece
Obesity in childhood and adolescence represents one of the most challenging public health problems of the 21st century owing to its epidemic proportions worldwide and the associated significant morbidity, mortality and public health costs. In Greece, the prevalence of overweight and obesity in childhood and adolescence exceeds 30–35%. To address the increasing prevalence of overweight and obesity in children and adolescents in our country, we developed the ‘National e-Health Program for the Prevention and Management of Overweight and Obesity in Childhood and Adolescence’, which provides specific and detailed guidance to all primary health care physicians about the personalized management of children and adolescents with overweight or obesity. In the present study we evaluated 2400 children and adolescents [mean age ± SD: 10.10 ± 0.09 years.; Males: 1088, Females: 1312; Obesity (n = 1370, 57.1%), Overweight (n = 674, 28.1%), normal BMI (n = 356, 14.8%)], who followed the personalized multi-disciplinary management plan specified by the ‘National e-Health Program for the Prevention and Management of Overweight and Obesity in Childhood and Adolescence’, and were studied prospectively for 1 year. We demonstrated that at the end of the first year, the prevalence of obesity decreased by 32.1%, the prevalence of overweight decreased by 26.7%, and the cardiometabolic risk factors improved significantly. These findings indicate that our National e-Health Program is effective at reducing the prevalence of overweight and obesity in childhood and adolescence after one year of intervention in the largest sample size reported to date. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Hair Cortisol Concentrations in Overweight and Obese Children and Adolescents
Introduction: Obesity in childhood and adolescence is associated with complications that resemble those seen in hypercortisolism. Hair cortisol concentration (HCC) in children is a reliable marker of long-term endogenous cortisol concentrations. We determined HCC in overweight and obese children and adolescents, and examined the relation between HCC and other cardiometabolic parameters. Methods: Three hundred children and adolescents aged 4-18 years (mean age ± standard error of the mean [SEM]: 10.49 ± 0.15 years; 140 [46.7%] obese, 94 [31.3%] overweight, 66 [22%] of normal BMI; 76 males, 224 females) were studied prospectively. Blood samples for determination of hematological, biochemical, and endocrinologic parameters were obtained. Systolic (SBP) and diastolic blood pressure (DBP) was determined. Scalp hair samples were collected from the posterior vertex, and HCC was measured using an electrochemiluminescence immunoassay. Results: Obese subjects had significantly higher SBP, DBP, waist and hip circumferences, waist-to-hip ratio, waist-to-height ratio, ALT, γ-GT, triglycerides, apolipoprotein-B, insulin, and HbA1C concentrations than overweight and normal-BMI subjects. HCC did not differ significantly among the three groups of subjects (mean ± SEM: 8.74 ± 0.43 vs. 8.88 ± 0.52 vs. 9.33 ± 0.72, all p > 0.05). No significant association was noted between HCC and cardiometabolic or body composition parameters. HCC was significantly higher in prepubertal girls than prepubertal boys (9.45 ± 0.38 vs. 7.35 ± 0.39, p = 0.007). Conclusion: In our study, overweight and obesity was not associated with elevated HCC. Furthermore, no association was found between HCC with cardiometabolic parameters and fat mass. Further studies are required to delineate the association between overweight/obesity and HCC. © 2019 S. Karger AG, Basel. Copyright: All rights reserved
Novel e-health applications for the management of cardiometabolic risk factors in children and adolescents in greece
Obesity in childhood and adolescence represents a major health problem. Novel e-Health technologies have been developed in order to provide a comprehensive and personalized plan of action for the prevention and management of overweight and obesity in childhood and adolescence. We used information and communication technologies to develop a “National Registry for the Prevention and Management of Overweight and Obesity” in order to register online children and adolescents nationwide, and to guide pediatricians and general practitioners regarding the management of overweight or obese subjects. Furthermore, intelligent multi-level information systems and specialized artificial intelligence algorithms are being developed with a view to offering precision and personalized medical management to obese or overweight subjects. Moreover, the Big Data against Childhood Obesity platform records behavioral data objectively by using inertial sensors and Global Positioning System (GPS) and combines them with data of the environment, in order to assess the full contextual framework that is associated with increased body mass index (BMI). Finally, a computerized decision-support tool was developed to assist pediatric health care professionals in delivering personalized nutrition and lifestyle optimization advice to overweight or obese children and their families. These e-Health applications are expected to play an important role in the management of overweight and obesity in childhood and adolescence. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Fast eating is associated with increased bmi among high-school students
Fast self-reported eating rate (SRER) has been associated with increased adiposity in children and adults. No studies have been conducted among high-school students, and SRER has not been validated vs. objective eating rate (OBER) in such populations. The objectives were to investigate (among high-school student populations) the association between OBER and BMI z-scores (BMIz), the validity of SRER vs. OBER, and potential differences in BMIz between SRER categories. Three studies were conducted. Study 1 included 116 Swedish students (mean ± SD age: 16.5 ± 0.8, 59% females) who were eating school lunch. Food intake and meal duration were objectively recorded, and OBER was calculated. Additionally, students provided SRER. Study 2 included students (n = 50, mean ± SD age: 16.7 ± 0.6, 58% females) from Study 1 who ate another objectively recorded school lunch. Study 3 included 1832 high-school students (mean ± SD age: 15.8 ± 0.9, 51% females) from Sweden (n = 748) and Greece (n = 1084) who provided SRER. In Study 1, students with BMIz ≥ 0 had faster OBER vs. students with BMIz < 0 (mean difference: +7.7 g/min or +27%, p = 0.012), while students with fast SRER had higher OBER vs. students with slow SRER (mean difference: +13.7 g/min or +56%, p = 0.001). However, there was “minimal” agreement between SRER and OBER categories (κ = 0.31, p < 0.001). In Study 2, OBER during lunch 1 had a “large” correlation with OBER during lunch 2 (r = 0.75, p < 0.001). In Study 3, fast SRER students had higher BMIz vs. slow SRER students (mean difference: 0.37, p < 0.001). Similar observations were found among both Swedish and Greek students. For the first time in high-school students, we confirm the association between fast eating and increased adiposity. Our validation analysis suggests that SRER could be used as a proxy for OBER in studies with large sample sizes on a group level. With smaller samples, OBER should be used instead. To assess eating rate on an individual level, OBER can be used while SRER should be avoided. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
A Comprehensive Multidisciplinary Management Plan Is Effective in Reducing the Prevalence of Overweight and Obesity in Childhood and Adolescence
Background: Obesity in childhood and adolescence represents a major health problem of our century. In Greece, 30-35% of children and adolescents are overweight or obese. Objective and Hypotheses: To investigate the effectiveness of a comprehensive multidisciplinary personalized management plan at reducing the prevalence of overweight and obesity in childhood and adolescence. Patients and Methods: One thousand (n = 1,000) children and adolescents aged 2-18 years (mean age ± SD: 10.09 ± 2.86 years; 520 females, 480 males) were studied prospectively. Subjects were classified as obese (n = 579, 57.9%), overweight (n = 295, 29.5%) or having a normal body mass index (BMI) (n = 126, 12.6%) according to the International Obesity Task Force cutoff points. All subjects were evaluated by a multidisciplinary team at frequent intervals, received personalized advice on diet and exercise and were studied prospectively for 1 year. Detailed clinical evaluation and laboratory investigations were performed at the beginning and at the end of the study. Results: At initial evaluation, 57.9% of subjects were obese, 29.5% overweight and 12.6% of normal BMI. Indices of cardiometabolic disease were higher in obese than in overweight and normal-BMI subjects. Following 1 year of multidisciplinary management interventions, the prevalence of obesity decreased by 16.8%, the prevalence of normal BMI increased by 8.2%, and all cardiometabolic indices improved significantly. Conclusions: A personalized multidisciplinary management plan is effective at reducing the prevalence of obesity in childhood and adolescence. © 2020 S. Karger AG. All rights reserved