97,616 research outputs found
The Still Dark Side of the Moon: Molecular Mechanisms of Lunar-Controlled Rhythms and Clocks
No full text: Starting with the beginning of the last century, a multitude of scientific studies has documented that the lunar cycle times behaviors and physiology in many organisms. It is plausible that even the first life forms adapted to the different rhythms controlled by the moon. Consistently, many marine species exhibit lunar rhythms, and also the number of documented "lunar-rhythmic" terrestrial species is increasing. Organisms follow diverse lunar geophysical/astronomical rhythms, which differ significantly in terms of period length: from hours (circalunidian and circatidal rhythms) to days (circasemilunar and circalunar cycles). Evidence for internal circatital and circalunar oscillators exists for a range of species based on past behavioral studies, but those species with well-documented behaviorally free-running lunar rhythms are not typically used for molecular studies. Thus, the underlying molecular mechanisms are largely obscure: the dark side of the moon. Here we review findings that start to connect molecular pathways with moon-controlled physiology and behaviors. The present data indicate connections between metabolic/endocrine pathways and moon-controlled rhythms, as well as interactions between circadian and circatidal/circalunar rhythms. Moreover, recent high-throughput analyses provide useful leads toward pathways, as well as molecular markers. However, for each interpretation, it is important to carefully consider the, partly substantially differing, conditions used in each experimental paradigm. In the future, it will be important to use lab experiments to delineate the specific mechanisms of the different solar- and lunar-controlled rhythms, but to also start integrating them together, as life has evolved equally long under rhythms of both sun and moon
Joshua Davis: Author of Spare Parts
No full textCitation: K-State First (2016). Joshua Davis: Author of Spare Parts [Flier]. Manhattan, Kansas: K-State First.Flyer advertising Joshua Davis's author talk at Kansas State University
Steven Johnson Author Talk Poster
No full textK-State Book NetworkA poster advertising an author talk by Steven Johnson at Kansas State University on September 3, 2014. Steven Johnson's book "The Ghost Map" was the 2014-2015 common book
Linguistische Textanalyse. Überlegungen zur Gliederung von Texten
No full textGülich E, Heger K, Raible W. Linguistische Textanalyse. Überlegungen zur Gliederung von Texten. Papiere zur Textlinguistik. Vol 8 2., durchges. u. erg. Aufl. Hamburg: Buske; 1979
Populations and pathways: Genomic approaches to understanding population structure and environmental adaptation
No full textThe field of Genomics has essentially been fuelled by medical research with developments in human gene therapy, such as the Human Genome Project. This major international undertaking resulted in a significantly increased sequencing capacity, a dramatic decrease in the time and cost of sequencing and also the computational effort required for the analysis. Marine biologists are taking advantage of this high throughput technology, hence, the tools are now available to answer questions that would have not been possible even five years ago. Genomics, in terms of studying DNA, can effectively define the genetic structure of populations and as a consequence the mapping of species boundaries, approximate drift in populations and accurately measure biodiversity. Studying transcribed sequences (RNA) enables the identification of changes at the cellular level associated with the adaptation of species to particular habitats and now, in our changing environment, predicts their ability to survive perturbation.
The aim of this chapter is to familiarize the reader with the most commonly used genomic techniques that are available for population and adaptation studies. These encompass both DNA based methodologies for population studies and RNA based techniques for expression studies. Which technique is used largely depends on the species under study and the resources available. In environmental research it is important to understand that “resources” does not just refer to money for sequencing and library production, but also access to starting material and the ability to store the material successfully, often under difficult conditions. For example, a cruise to investigate a particular hydrothermal vent may only happen once in a researcher’s lifetime and so material will be scarce, numbers will be limited and it may not be possible to store the material at a low enough temperature to prevent RNA degradation (thereby excluding expression studies). Also species availability tends to be on what is there at the time, rather than being able to perform a calculated choice for which species is the best to study. In other studies such as aquaculture or invasive species, a means has to be found to work on a particular species even if the material is intractable as there is a defined requirement for work in that area. So having outlined the techniques, the question is how to use them?
In this chapter specific examples will be used to demonstrate how such techniques are being used to address these important ecological issues in the marine environment, concentrating on lower vertebrates (fish) and invertebrates. These encompass both population analyses and gene expression (functional) studies to understand how populations have adapted to and interact with, their environment.
Ultimately, the challenge for the marine biologist is to utilize the tools produced for the study of model organisms, where significant amounts of sequence data exist (i.e. resource rich) and to develop these for non-model species, essentially from a zero base-line. It is not an easy task
Genomic approaches in aquaculture and fisheries
No full textDespite the enormous input into the worldwide development of fish and shellfish farming in the recent decades, in part as an attempt to minimize the impact of fishing on already overexploited natural populations, the application of genomics to aquaculture and fisheries remains poorly developed. Improving state-of-the-art genomics research in various aquaculture systems, as well as its industrial applications, remains one of the major challenges in this area and should be the focus of well developed strategies to be implemented in the next generation of projects. This chapter will first provide an overview of the genomic tools and resources available, then discuss the application of genomic approaches to the improvement of fish and shellfish farming (e.g. breeding, reproduction, growth, nutrition and product quality), including the evaluation of stock diversity and the use of selection procedures. The chapter will also discuss the use of genomic approaches to study and monitor natural fish and shellfish populations and to understand interactions within their ecosystems
Linguistische Textanalyse. Überlegungen zur Gliederung von Texten
No full textGülich E, Heger K, Raible W. Linguistische Textanalyse. Überlegungen zur Gliederung von Texten. Papiere zur Textlinguistik. Vol 8. Hamburg: Buske; 1974
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Spatial language use predicts spatial memory of children: Evidence from sign, speech, and speech-plus-gesture
No full textThere is a strong relation between children’s exposure to spatial terms and their later memory accuracy. In the current study, we tested whether the production of spatial terms by children themselves predicts memory accuracy and whether and how language modality of these encodings modulates memory accuracy differently. Hearing child speakers of Turkish and deaf child signers of Turkish Sign Language described pictures of objects in various spatial relations to each other and later tested for their memory accuracy of these pictures in a surprise memory task. We found that having described the spatial relation between the objects predicted better memory accuracy. However, the modality of these descriptions in sign, speech, or speech-plus-gesture did not reveal differences in memory accuracy. We discuss the implications of these findings for the relation between spatial language, memory, and the modality of encoding
The Nereid on the rise: Platynereis as a model system
No full text: The Nereid Platynereis dumerilii (Audouin and Milne Edwards (Annales des Sciences Naturelles 1:195-269, 1833) is a marine annelid that belongs to the Nereididae, a family of errant polychaete worms. The Nereid shows a pelago-benthic life cycle: as a general characteristic for the superphylum of Lophotrochozoa/Spiralia, it has spirally cleaving embryos developing into swimming trochophore larvae. The larvae then metamorphose into benthic worms living in self-spun tubes on macroalgae. Platynereis is used as a model for genetics, regeneration, reproduction biology, development, evolution, chronobiology, neurobiology, ecology, ecotoxicology, and most recently also for connectomics and single-cell genomics. Research on the Nereid started with studies on eye development and spiralian embryogenesis in the nineteenth and early twentieth centuries. Transitioning into the molecular era, Platynereis research focused on posterior growth and regeneration, neuroendocrinology, circadian and lunar cycles, fertilization, and oocyte maturation. Other work covered segmentation, photoreceptors and other sensory cells, nephridia, and population dynamics. Most recently, the unique advantages of the Nereid young worm for whole-body volume electron microscopy and single-cell sequencing became apparent, enabling the tracing of all neurons in its rope-ladder-like central nervous system, and the construction of multimodal cellular atlases. Here, we provide an overview of current topics and methodologies for P. dumerilii, with the aim of stimulating further interest into our unique model and expanding the active and vibrant Platynereis community
Exact Elimination of Cycles in Graphs
No full textOne of the standard basic steps in drawing hierarchical graphs is to invert some arcs of the given graph to make the graph acyclic. We discuss exact and parameterized algorithms for this problem. In particular we examine a graph class called (1, n)-graphs, which contains cubic graphs. We discuss exact and parameterized algorithms, where we use a non-standard measure approach for the analysis. Especially the analysis of the parameterized algorithm is of special interest, as it is not an amortized analysis modelled by ’finite states’ but is rather a ’top-down’ amortized analysis. For (1, n)-graphs we achieve a running time of O ∗ (1.1871 m) and O ∗ (1.212 k), for cubic graphs O ∗ (1.1798 m) and O ∗ (1.201 k), respectively. As a by-product the the trivial bound of 2 n for Feedback Vertex Set on planar directed graphs is broken
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