Phylogenetic Relationships among North American Popcorns and Their Evolutionary Links to Mexican and South American Popcorns

To determine genetic relationships among representative popcorns (Zea mays L.) of the New World, 56 maize populations from the USA and nine Latin American countries were characterized for 29 morphological traits, 18 isozyme loci, and 31 SSR loci. Cluster and principal component analyses were performed upon standardized morphological data and allelic frequencies from isozyme and SSR loci to elucidate relationships among populations within a geographical and historical context. Three groups of popcorn, with distinctive morphological characteristics and genetic profiles, were identified in the North American populations. The first group includes the North American Yellow Pearl Popcorns, which are currently the most important for U.S. commercial production. This group could be derived from introductions of the race Curagua from Chile into New England in the 19th Century. The second group includes the North American Pointed Rice Popcorns, which probably originated from the complex of traditional races of pointed popcorns from Latin America, such as Palomero Toluqueño, Confite Puntiagudo, Canguil, and Pisankalla, which diffused from the highlands of central Mexico into northern Mexico and then into southwestern USA. The third group includes the North American Early Popcorns, which show a marked influence of Northern Flint maize, from which they probably acquired the trait of early maturity. This third group also shows genetic influences of maize from northwestern Mexico and even from early European varieties of popcorn introduced late in the 19th Century. We propose that the three groups of North American popcorn identified in this study be recognized taxonomically as distinct races, and we provide characteristic traits as well as isozyme and SSR alleles to define the new races

Race diversity in dryland maize (Zea mays L.) landraces from southern Nuevo León, Mexico

This study was done for reviewing the diversity and distribution of native maize grown at southern Nuevo León, Mexico, in 40 accessions collected in the area. Information obtained was on the production unit and on the ears traits, according to the CONABIO guidelines. In this area maize is usually grown during the Spring-Summer period, and using little technology, without fertilization or pest control. The 40 accessions correspond to seven races and seven interracial crosses. The most frequent maize races were Ratón and Cónico Norteño, especially in dry areas with little rain. Races Celaya, Tablilla de Ocho and Elotes Cónicos found in this study, had not been previously reported; but the Tabloncillo and Olotillo races that had previously been reported were no longer found. Three collections stood out for producing large ears with large kernels, thus having a high yield potential. Native maize harvested in dryland areas might offer advantages to be grown under harsh environments.Objective: To analyze the race diversity and geographic distribution of the native maize landraces currently cropped at southern Nuevo León, México. Design/Methodology/Approach: Data was obtained from 41 accessions which represent the commercial production in the dry land area, where fertilization and pest control are scarcely used. Landraces were classified according to the CONABIO guidelines for ear traits. Results: The measured accessions correspond to seven maize races and to seven interracial crosses. The two most frequent maize races were Ratón and Cónico Norteño, mostly located in the dry areas with less rain. Study Limitations/Implications: Three races, Celaya, Tablilla de Ocho and Elotes Cónicos, had not been previously reported; while two formerly reported races Tabloncillo and Olotillo, were no longer found. This study did not include the grain-colored accessions. Findings/Conclusions: Three collections stood out for producing large ears with large kernels, thus showing a high yield potential. The maize landraces harvested in dryland areas might offer advantages to be grown under harsh environments or be used as gene donors for drought tolerance

Morphological variability of native maize (Zea mays L.) of the west highland of Puebla and east highland of Tlaxcala, Mexico

The objective of this research was to assess the morphological variability of maize landraces native of the west highland of Puebla and east highland of Tlaxcala, México, in order to, besides define it, related it to races, commercial varieties and with the altitude of the localities of seed collection. The genetic resources evaluated were 134 accessions collected in 34 localities, along with 10 controls. Experiments were established on three localities using a Lattice 12 x 12. Thirty-two morphological traits were analyzed, 27 of them resulting with highly significant differences, reflecting the high variability at the level of morphological characters, many of them of agronomic interest. From variance analysis 16 traits were selected for use in a cluster analysis through the Modified Localization Method, which joint the populations in six groups, most of them in the group 1, with morphological traits of long cycle varieties: high plants, with greater primary branches of the tassel, greater ear diameter and length, and greater grain length and width. The conclusions indicate that the morphological variability of Landraces is not associated with the altitude of localities of seed collection and that these have more relation with Chalqueño race, small with Conico race, absent with Conico Norteño and Palomero Toluqueño races and almost absent with commercial varieties.The objective of this research was to assess the morphological variability of maize landraces native of the west highland of Puebla and east highland of Tlaxcala, México, in order to, besides define it, related it to races, commercial varieties and with the altitude of the localities of seed collection. The genetic resources evaluated were 134 accessions collected in 34 localities, along with 10 controls. Experiments were established on three localities using a Lattice 12 x 12. Thirty-two morphological traits were analyzed, 27 of them resulting with highly significant differences, reflecting the high variability at the level of morphological characters, many of them of agronomic interest. From variance analysis 16 traits were selected for use in a cluster analysis through the Modified Localization Method, which joint the populations in six groups, most of them in the group 1, with morphological traits of long cycle varieties: high plants, with greater primary branches of the tassel, greater ear diameter and length, and greater grain length and width. The conclusions indicate that the morphological variability of Landraces is not associated with the altitude of localities of seed collection and that these have more relation with Chalqueño race, small with Conico race, absent with Conico Norteño and Palomero Toluqueño races and almost absent with commercial varieties

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

Calibration of the CMS Drift Tube Chambers and Measurement of the Drift Velocity with Cosmic Rays

Peer reviewe

CMS Data Processing Workflows during an Extended Cosmic Ray Run

Peer reviewe

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

Commissioning and performance of the CMS silicon strip tracker with cosmic ray muons

This is the Pre-print version of the Article. The official published version of the Paper can be accessed from the link below - Copyright @ 2010 IOPDuring autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comprehensive test, in the presence of the 3.8 T magnetic field produced by the CMS superconducting solenoid. Cosmic ray muons were detected in the muon chambers and used to trigger the readout of all CMS sub-detectors. About 15 million events with a muon in the tracker were collected. The efficiency of hit and track reconstruction were measured to be higher than 99% and consistent with expectations from Monte Carlo simulation. This article details the commissioning and performance of the Silicon Strip Tracker with cosmic ray muons.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)