B843: The Ecology, Economics, and Management of Potato Cropping Systems: A Report of the First Four Years of the Maine Potato Ecosystem Project

The bulletin reports on the first four years of the Maine Potato Ecosystem Project, a long-term, multidisciplinary study of alternative crop management strategies. The study site is a 15-acre tract on the northern boundary of the University of Maine\u27s Aroostook Farm in Presque Isle, Maine, divided into 96 main plots that are grouped into four blocks. Each block is an area where soil survey data show similar soil characteristics. Thus, given the same production inputs, the crop output is expected to be the same on each plot within a block. Within each block there are 24 plots to which the different treatments have been randomly assigned. A treatment is a particular combination of the following factors: (1) pest management—conventiorial, reduced input, or biological; (2) potato variety—Atlantic or Superior; and (3) soil management—amended or unamended.https://digitalcommons.library.umaine.edu/aes_bulletin/1025/thumbnail.jp

Supersymmetric D-term Inflation, Reheating and Affleck-Dine Baryogenesis

The phenomenology of supersymmetric models of inflation, where the inflationary vacuum energy is dominated by D-terms of a U(1), is investigated. Particular attention is paid to the questions of how to arrange for sufficient e-folds of inflation to occur, what kind of thermal history is expected after the end of inflation, and how to implement successful baryogenesis. Such models are argued to require a more restrictive symmetry structure than previously thought. In particular, it is non-trivial that the decays of the fields driving D-inflation can reheat the universe in such a way as to avoid the strong gravitino production constraints. We also show how the initial conditions for Affleck-Dine baryogenesis can arise in these models and that the simplest flat directions along which baryon number is generated can often be ruled out by the constraints coming from decoherence of the condensate in a hot environment. At the end, we find that successful reheating and baryogenesis can take place in a large subset of D-inflationary models.Comment: 23 pages LaTe

Constraints on the braneworld from compact stars

According to the braneworld idea, ordinary matter is confined on a three-dimensional space (brane) that is embedded in a higher-dimensional space-time where gravity propagates. In this work, after reviewing the limits coming from general relativity, finiteness of pressure and causality on the brane, we derive observational constraints on the braneworld parameters from the existence of stable compact stars. The analysis is carried out by solving numerically the brane-modified Tolman–Oppenheimer–Volkoff equations, using different representative equations of state to describe matter in the star interior. The cases of normal dense matter, pure quark matter and hybrid matter are considered.info:eu-repo/semantics/publishedVersio

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Sensory and skeletal development and growth in relation to the duration of the embryonic and larval stages in damselfishes (Pomacentridae)

Several trends were found in comparisons of rates of growth and development of larvae of four coral-reef damselfishes (Chromis atripectoralis, Pomacentrus amboinensis, Premnas biaculeatus, Acanthochromis polyacanthus), which were reared under constant temperature conditions in the laboratory, and which varied in their early life stage durations (respectively, egg stage durations were 2, 4, 7, 16; larval stage durations were 25, 23, 14, 0). Parameters measured included standard length, muscle area, eye diameter, and selected stages of retinal development, olfactory development, and skeletal ossification. Rates of ossification and olfactory development were inversely related to growth rate (in length and muscle area) among most species. Rates of eye growth and retinal development were also negatively correlated among all species. These results are consistent with the concept of a trade-off between growth and development. We observed a positive relationship between egg stage duration and developmental rate, and a negative correlation between larval stage duration and developmental rate. Acanthochromis developed slower than predicted by the general trends, although retinal development was very rapid. Specific retinal stages correlated with settlement, regardless of ontogenetic rates. Olfactory development was especially rapid in the anemonefish Premnas biaculeatus, which imprints to olfactory cues as an embryo. Skeletal ossification was rapid in species with pelagic larvae, and much slower in the benthic brooder. Literature-derived data on size and age at hatching and settlement from > 40 species of tropical pomacentrids were transformed into growth and developmental rates; correlations of these literature-derived parameters were mostly consistent with our controlled four-species comparison