INTERACTION OF RESEARCH AND SUBJECTS IN SOCIAL INTERVENTION STUDIES

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74684/1/j.1749-6632.1973.tb47621.x.pd

Maize Cultivar Performance under Diverse Organic Production Systems

Maize (Zea mays L.) performance can vary widely between different production systems. The need for high-performing hybrids for organic systems with wide adaptation to various macroenvironments is becoming increasingly important. The goal of this study was to characterize inbred lines developed by distinct breeding programs for their combining ability and hybrid yield performance across diverse organic environments. Parent lines were selected from five different breeding programs to give a sample of publically available germplasm with potential for use in organic production systems with expired plant variety protection (Ex-PVP) and current commercial inbreds as benchmarks. A North Carolina Design II mating design was used to produce all possible cross combinations between seven lines designated as males and seven lines designated as females. A significantly positive general combining ability for the female inbred UHF134 suggests that it performs well in hybrid combination. Significant general combining ability was not observed for any male inbred line in this study. Several significantly positive specific combining abilities suggest that nonadditive genetic effects play an important role in determining yield in this germplasm. Further analysis revealed that hybrids containing either an Ex-PVP line or a commercial inbred line were on average superior to hybrids containing only inbreds developed by the cooperators of this study. This demonstrates the utility of testing inbreds from diverse sources when developing hybrids for organic production systems

The potential impact of improvements in contraception on fertility and abortion in western countries

Survey information on fertility intentions, patterns of contraceptive use, contraceptive failures and abortions is used to develop estimates of unwanted births and of unplanned pregnancies for seven countries, by method of contraception. Potential improvements in contraception, leading to more use of highly efficient methods are considered, and several scenarios for improved contraceptive use are presented. The impact each would have on fertility levels and on abortion rates is estimated. Although improvements in contraception will have only a limited impact on fertility — which is already very low — their impact on abortion could be considerable Les auteurs utilisent des données d'enquêtes sur les intentions de procréation, le recours à la contraception, les échecs de la contraception et l'avortement pour évaluer les naissances non désirées et les grossesses non planifiées, selon la méthode de contraception utilisée, dans sept pays. Ils envisagent d'éventuels progrès de la contraception conduisant à un élargissement de l'emploi de méthodes très efficaces, et évaluent, dans différents scénarios de progrès du recours à la contraception, son impact sur les niveaux de la fécondité et de l'avortement. Si le progrès de la contraception n'aura qu'un effet limité sur la fécondité — déjà très basse — son impact sur les niveaux de l'avortement pourrait être considérable.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42729/1/10680_2005_Article_BF01797090.pd

Agronomic and Kernel Compositional Traits of Blue Maize Landraces from the Southwestern United States

Diverse landraces of maize have been cultivated for centuries in the southwestern United States and northern Mexico primarily for human food consumption. A striking feature of these landraces is the wide array of kernel colors displayed. Traditional cultivation is declining, but blue maize has received increasing commercial interest due to rising consumer demand for unique food products with health benefits and special culinary uses. We evaluated grain yield, agronomic and morphological traits, and analyzed the kernel biochemical composition of five blue and one purple landraces representative of diversity in the Southwest. These were compared with selected open-pollinated populations derived from Southwest and Corn Belt blue maize at several New Mexico locations in 2012 and 2013. Kernel amino acids, oil, protein, starch, fatty acids, crude fiber, ash and anthocyanin pigment contents were determined. Grain yield across all locations, years, and accessions averaged 2.11 Mg ha−1. Navajo Blue and Hopi Blue were the highest and lowest yielding accessions, respectively. The majority of southwestern landraces displayed higher oil content, and two displayed higher protein content, than the Corn Belt Dent variety. Little variation in total amino acid content was observed. Several southwestern floury accessions displayed ∼10% greater lysine and methionine than did dent or flint genotypes. Considerable variation for plant, ear, and kernel compositional traits within and across southwestern landraces was consistent with the presence of racial admixtures. The health-promoting properties of anthocyanin-rich landraces contribute to sound dietary nutrition and human health. This study further illustrates the diversity of southwestern maize and supports the rationale for their continued conservation through sustained cultivation and utilization. Directed selection to improve grain yield and uniformity will be necessary to enhance their potential for commercial production

Long-Term Relationships between Synaptic Tenacity, Synaptic Remodeling, and Network Activity

Long term time-lapse imaging reveals that individual synapses undergo significant structural remodeling not only when driven by activity, but also when network activity is absent, raising questions about how reliably individual synapses maintain connections