Identification of Mexican Maize Races (Zea mays L.) with Drought Tolerance using Osmotic Potential Experiments for Genetic Breeding

Received: July 13th, 2023 ; Accepted: September 23rd, 2023 ; Published: October 23rd, 2023 ; Correspondence: [email protected] (Zea mays L.) is the third most important cereal crop worldwide after wheat and rice per cultivated area with 249,225,876 hectares and the most important crop for number of harvested grain tons with 1,482,997,259 in 2021. Some native Mexican maize races could be a source for drought tolerance to improve commercial cultivars and hybrids. The experiments were conducted using various osmotic pressures (OP) induced by polyethylene glycol (PEG-6000) (0, -0.05, -0.15, -0.30 and -0.49 MPa) simulating an increase of drought stress in ten maize genotypes. The main objectives of this study were the evaluation of germination and seedling growth components in response to drought stress and the identification of sources of drought tolerance in Mexican maize races. Apachito-r showed an increased germination in 110.4%, Cristalino-079 had a decreased germination in 98.7% and Cristalino-279 reduced its germination in a 91.1% compared to the control. Apachito-r outstands in root length at -0.05 OP increasing 200.1% and at -0.49 increasing 129.8%. The values for stem length were decreasing as the OP was increasing and only Apachito-r showed a significant difference at -0.30 MPa decreasing 39.8% respect to its control. Cristalino-279 showed significant difference in the variable root fresh weight and its value outstand at -0.15 increasing 267.2%, at -0.30 increasing 281.6% and at -0.49 MPa increasing 189.3% compared to the control in water. The variable root dry weight had the highest value for Apachito-r at -0.05 MPa increasing in a 189.4%, decreasing at -0.15 in 72% and at -0.30 MPa in a 79.8% and increasing at -0.49 MPa in 112.3%. Also noteworthy are E-zapata-r increasing 190.5% and Cristalino-061 increasing 142.9% at -0.30. E-zapata-r at -0.49 increased 115.1%. Cristalino-279 showed significant difference in the variable stem fresh weight and its value outstand at -0.05, -0.15 and -0.30 MPa increasing 146.7%, 103.7% and 60.2% respectively. Finally, in stem dry weight the tendency was to decrease as OP was increasing, however Cristalino-279 showed differences at -0.30 decreasing in 89.5% and at -0.49 MPa increasing in a 143.5% respect to the control. The most drought tolerant genotypes were Cristalino-279, Apachito-r, Azul and 8-carreras-PP. The most tolerant genotypes showed greater root length, greater root fresh and dry weight, better germination and greater stem length. Resistant and susceptible genotypes are ideal material to understand the physical and chemical mechanisms related to drought tolerance. Cristalino-279 shows the best level of drought tolerance at all levels of osmotic pressure, this genotype can be used as a source of drought tolerance for the improvement of commercial maize

Theoretical description of phase coexistence in model C60

We have investigated the phase diagram of the Girifalco model of C60 fullerene in the framework provided by the MHNC and the SCOZA liquid state theories, and by a Perturbation Theory (PT), for the free energy of the solid phase. We present an extended assessment of such theories as set against a recent Monte Carlo study of the same model [D. Costa et al, J. Chem. Phys. 118:304 (2003)]. We have compared the theoretical predictions with the corresponding simulation results for several thermodynamic properties. Then we have determined the phase diagram of the model, by using either the SCOZA, or the MHNC, or the PT predictions for one of the coexisting phases, and the simulation data for the other phase, in order to separately ascertain the accuracy of each theory. It turns out that the overall appearance of the phase portrait is reproduced fairly well by all theories, with remarkable accuracy as for the melting line and the solid-vapor equilibrium. The MHNC and SCOZA results for the liquid-vapor coexistence, as well as for the corresponding critical points, are quite accurate. All results are discussed in terms of the basic assumptions underlying each theory. We have selected the MHNC for the fluid and the first-order PT for the solid phase, as the most accurate tools to investigate the phase behavior of the model in terms of purely theoretical approaches. The overall results appear as a robust benchmark for further theoretical investigations on higher order C(n>60) fullerenes, as well as on other fullerene-related materials, whose description can be based on a modelization similar to that adopted in this work.Comment: RevTeX4, 15 pages, 7 figures; submitted to Phys. Rev.

Liquid-Solid Transition of Hard Spheres Under Gravity

We investigate the liquid-solid transition of two dimensional hard spheres in the presence of gravity. We determine the transition temperature and the fraction of particles in the solid regime as a function of temperature via Even-Driven molecular dynamics simulations and compare them with the theoretical predictions. We then examine the configurational statistics of a vibrating bed from the view point of the liquid-solid transition by explicitly determining the transition temperature and the effective temperature, T, of the bed, and present a relation between T and the vibration strength.Comment: 14 total pages, 4 figure

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

Neuroinflammatory disease as an isolated manifestation of hemophagocytic lymphohistiocytosis

Isolated neuroinflammatory disease has been described in case reports of familial hemophagocytic lymphohistiocytosis (FHL), but the clinical spectrum of disease manifestations, response to therapy and prognosis remain poorly defined. We combined an international survey with a literature search to identify FHL patients with (i) initial presentation with isolated neurological symptoms; (ii) absence of cytopenia and splenomegaly at presentation; and (iii) systemic HLH features no earlier than 3 months after neurological presentation. Thirty-eight (20 unreported) patients were identified with initial diagnoses including acute demyelinating encephalopathy, leukoencephalopathy, CNS vasculitis, multiple sclerosis, and encephalitis. Median age at presentation was 6.5 years, most commonly with ataxia/gait disturbance (75%) and seizures (53%). Diffuse multifocal white matter changes (79%) and cerebellar involvement (61%) were common MRI findings. CSF cell count and protein were increased in 22/29 and 15/29 patients, respectively. Fourteen patients progressed to systemic inflammatory disease fulfilling HLH-2004 criteria at a mean of 36.9 months after initial neurological presentation. Mutations were detected inPRF1in 23 patients (61%),RAB27Ain 10 (26%),UNC13Din 3 (8%),LYSTin 1 (3%), andSTXBP2in 1 (3%) with a mean interval to diagnosis of 28.3 months. Among 19 patients who underwent HSCT, 11 neurologically improved, 4 were stable, one relapsed, and 3 died. Among 14 non-transplanted patients, only 3 improved or had stable disease, one relapsed, and 10 died. Isolated CNS-HLH is a rare and often overlooked cause of inflammatory brain disease. HLH-directed therapy followed by HSCT seems to improve survival and outcome

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions. © Copyright

Diminishing benefits of urban living for children and adolescents’ growth and development

Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified. © 2023, The Author(s)