The quality of political information

The article conceptualizes the quality of political information and shows how the concept can be used for empirical research. I distinguish three aspects of quality (intelligibility, relevance, validity) and use them to judge the constituent foundations of political information, that is component claims (statements of alleged facts) and connection claims (argumentative statements created by causally linking two component claims). The resulting conceptual map thus entails six manifestations of information quality (component claimintelligibility, connection claim intelligibility, component claimrelevance, connection claim relevance, component claim validity, and connection claim validity). I explain how the conceptual map can be used to make sense of the eclectic variety of existing research, and how it can advance new empirical research, as a guide for determining variation in information quality, as a conceptual template for the analysis of different types of political messages and their common quality deficiencies, and as a generator of new research questions and theoretical expectations

A new skeleton of the cryptoclidid plesiosaur Tatenectes laramiensis reveals a novel body shape among plesiosaurs

Current knowledge of plesiosaurs of clade Cryptoclidia is constrained by a lack of fossils from outside the Oxford Clay deposits of England. Recent fieldwork in the Sundance Formation of the Bighorn Basin, Wyoming, has resulted in the recovery of significant new fossils of cryptoclidid plesiosaurs, including the small-bodied form Tatenectes laramiensis. A new partial skeleton of this taxon is reported here; it is the most complete and best-preserved example of the taxon found to date, comprising a complete dorsal vertebral series, many ribs and gastralia, and a complete pelvic girdle. This skeleton illuminates several unique features of the taxon, including a novel pattern of midline pachyostosis in the gastralia. In addition, a range of both axial and appendicular morphological features reveals that Tatenectes had a body shape unique among known plesiosaurs, characterized by extreme dorsoventral compression, and modest anteroposterior reduction. The combination of the new skeleton with information from previous finds allows the first reconstruction of the taxon. Tatenectes had a dorsoventrally compressed, oblate spheroid body shape, with a high skeletal mass concentration in the ventral elements. We hypothesize that these features were adaptations for increased near-surface stability, perhaps allowing access to above normal wave base, inshore environments in the shallow Sundance Seaway

Combinatorial control of temporal gene expression in the Drosophila wing by enhancers and core promoters

Abstract Background The transformation of a developing epithelium into an adult structure is a complex process, which often involves coordinated changes in cell proliferation, metabolism, adhesion, and shape. To identify genetic mechanisms that control epithelial differentiation, we analyzed the temporal patterns of gene expression during metamorphosis of the Drosophila wing. Results We found that a striking number of genes, approximately 50% of the Drosophila transcriptome, exhibited changes in expression during a time course of wing development. While cis-acting enhancer sequences clearly correlated with these changes, a stronger correlation was discovered between core-promoter types and the dynamic patterns of gene expression within this differentiating tissue. In support of the hypothesis that core-promoter type influences the dynamics of expression, expression levels of several TATA-box binding protein associated factors (TAFs) and other core promoter-associated components changed during this developmental time course, and a testes-specific TAF (tTAF) played a critical role in timing cellular differentiation within the wing. Conclusions Our results suggest that the combinatorial control of gene expression via cis-acting enhancer sequences and core-promoter types, determine the complex changes in gene expression that drive morphogenesis and terminal differentiation of the Drosophila wing epithelium.http://deepblue.lib.umich.edu/bitstream/2027.42/112935/1/12864_2012_Article_4965.pd

Active versus passive acquisition of spatial knowledge while controlling a vehicle in a virtual urban space in drivers and non-drivers

Historically real world studies have indicated a spatial learning advantage for active explorers of environments over those whose experience is more passive; a common contrast is made between car drivers and passengers. An experiment was conducted to explore the dual hypotheses that active explorers learn more about the layout of a virtual environment than passive observers and that real world car drivers will learn more regardless of their experimental Active/Passive status. Consistent with earlier studies in VEs, there was no benefit from activity (controlling exploration/movement), arguably because input control competes with spatial information acquisition. However, the results showed that Drivers were more accurate than Non-Drivers at indicating the positions of target locations on a map, in both active and passive conditions and had better route scores than Non-Drivers in the passive condition. It is argued that driving experience may convey a spatial learning advantage over and above activity per se

Doing what others do: norms, science, and collective action on global warming

Does rhetoric highlighting social norms or mentioning science in a communication affect individuals’ beliefs about global warming and/or willingness to take action? We draw from framing theory and collective-interest models of action to motivate hypotheses that are tested in two large web-based survey-experiments using convenience samples. Our results show that attitudes about global warming, support for policies that would reduce carbon emissions, and behavioral intentions to take voluntary action are strongly affected by norm- and science-based interventions. This has implications for information campaigns targeting voluntary efforts to promote lifestyle changes that would reduce greenhouse gas emissions

Multicolour interphase cytogenetics: 24 chromosome probes, 6 colours, 4 layers

From the late 1980s onwards, the use of DNA probes to visualise sequences on individual chromosomes (fluorescent in-situ hybridisation - FISH) revolutionised the study of cytogenetics. Following single colour experiments, more fluorochromes were added, culminating in a 24 colour assay that could distinguish all human chromosomes. Interphase cytogenetics (the detection of chromosome copy number in interphase nuclei) soon followed, however 24 colour experiments are hampered for this application as mixing fluorochromes to produce secondary colours produces images that are not easily distinguishable from overlapping signals. This study reports the development and use of a novel protocol, new fast hybridising FISH probes, and a bespoke image capture system for the assessment of chromosome copy number in interphase nuclei. The multicolour probe sets can be used individually or in sequential hybridisation layers to assess ploidy of all 24 human chromosomes in the same nucleus. Applications of this technique are in the investigation of chromosome copy number and the assessment of nuclear organisation for a range of different cell types including human sperm, cancer cells and preimplantation embryos

Differential influences of environment and self-motion on place and grid cell firing

Place and grid cells in the hippocampal formation provide foundational representations of environmental location, and potentially of locations within conceptual spaces. Some accounts predict that environmental sensory information and self-motion are encoded in complementary representations, while other models suggest that both features combine to produce a single coherent representation. Here, we use virtual reality to dissociate visual environmental from physical motion inputs, while recording place and grid cells in mice navigating virtual open arenas. Place cell firing patterns predominantly reflect visual inputs, while grid cell activity reflects a greater influence of physical motion. Thus, even when recorded simultaneously, place and grid cell firing patterns differentially reflect environmental information (or ‘states’) and physical self-motion (or ‘transitions’), and need not be mutually coherent

Odor supported place cell model and goal navigation in rodents

Experiments with rodents demonstrate that visual cues play an important role in the control of hippocampal place cells and spatial navigation. Nevertheless, rats may also rely on auditory, olfactory and somatosensory stimuli for orientation. It is also known that rats can track odors or self-generated scent marks to find a food source. Here we model odor supported place cells by using a simple feed-forward network and analyze the impact of olfactory cues on place cell formation and spatial navigation. The obtained place cells are used to solve a goal navigation task by a novel mechanism based on self-marking by odor patches combined with a Q-learning algorithm. We also analyze the impact of place cell remapping on goal directed behavior when switching between two environments. We emphasize the importance of olfactory cues in place cell formation and show that the utility of environmental and self-generated olfactory cues, together with a mixed navigation strategy, improves goal directed navigation